Носитель магнитной записи

Изобретение относится к технике магнитной записи и позволяет повысить качество маркировки носителя и улучшить его электромагнитные свойства . На немагнитную основу 1 с рабочим слоем 2 с одной стороны нанесен с противоположной стороны дополнительный слой 3 из немагнитного полимерного вещества с пигментом белого цвета, позволящим наносить на полученное покрытие маркировки типографским способом. Дополнительный слой уменьшает деформацию носителя . Приведено соотношение использованных компонентов. 1 ил., I табл. с S (Л К5 Сл 4 сд ...

Магнитная лента

Состав обратного слоя носителя магнитной записи

Изобретение относится к технике магнитной записи, а именно к технологии изготовления обратного слоя носителей магнитной записи, и может быть использовано при изготовлении магнитных носителей для видеозаписи. Цель - снижение коэффициента статического и динамического трения. Это достигается за счет дополнительного использования поливинилформальэтилаля (5,0-8,2 мас.%), бутанола (3,90-5,25 мас.%) и сплава стеариновой кислоты и бутилстеарата в соотношении 1:4-1:6 (1,00-1,65 мас.%) в композиции следующего состава, мас.%: аэросил 3,3-4,9 ацетиленовая сажа 6,6-9,8 полиуретановый эластомер СКУ-8М 5,0-8,2 гексаметоксиметилмеламин 1,00-1,65 додецилбензолсульфокислота 0,2-0,3 дихлорэтан 35,20-47,15 циклогексанон 20,6-31,1. 2 табл.

Audio tape cassette contg. magnetic tape - with coating of pigment and binder on rear face with specified max. coefft. of friction against felt cushion

Cassette (I) comprises (A) cassette housing (B) pair of hubs arranged so they rotate in (A) (C) magnetic tape which is wound around (B) with magnetic layer turned outwards, (D) guide part in (A) and guiding running of (C) (E) felt cushion between (B) and contacting rear face of (C) to press (C) against a magnetic head, (C) having coating (II) on rear face comprising a pigment and binder and having coefft. of friction against (E) of not more than 0.4. Pref. (A) is of synthetic resin esp. ethylene-propylene copolymer or phenolic resin, or composite of ethylene-propylene copolymer and CaCO3 and opt ZnO or of phenolic resin and glass fibres. (E) is of Angora rabbit hair. (II) has max. pencil hardness of 5H. (II) has max. ave. thickness along middle line of 0.03 micron. Pigment in (II) has max. hardness on Moh scale of 4, pigment in (II) is CaCO3. Binder in (II) is resin having max coeffct. of friction against (E) of 0.4 when (II) is formed only from this resin. Resin in (II) is vinyl chloride-vinyl ...

MAGNETISCHES AUFZEICHNUNGSMEDIUM

TRAEGERFOLIE FUER MAGNETISCHE INFORMATIONSTRAEGER UND DEREN HERSTELLUNG.

MAGNETISCHES AUFZEICHNUNGSMEDIUM MIT EINER RUECKUEBERZUGSSCHICHT

Magnetaufzeichnungsmedium

MAGNETIC RECORDING MEDIUM FOR IMAGE RECORDING

A ferromagnetic alloy image recording tape, wherein the stiffness of the entire tape is represented by the formula: where w: load (g) a: radius (mm) of the tape ring b: width (mm) of the tape d: deformation (mm) of the tape ring ...

Magnetic recording medium

A magnetic recording medium having a thin magnetic metal film on a non-magnetic base is disclosed. A surface layer is formed on either the thin magnetic metal film or the other side of the base or both by irradiating a coating of a polymer having an unsaturated bond polymerizable by radiation. A process for producing such magnetic recording medium is also disclosed.

Magnetic recording medium and method for producing the same

A magnetic recording medium comprises in combination a supporting member, a ferromagnetic thin film formed on one surface side of said supporting member, and a back layer provided on the other surface side of the supporting member The back layer is composed of filler material dispersed in a binder containing a radiation-sensitive curable resin, and then cured. ...

MAGNETIC RECORDING MEDIUM

MAGNETIC RECORDING MEDIUM

MAGNETIC RECORDING MEDIA AND DEVICE UTILIZING THE SAME

MAGNETIC RECORDING MEDIUM

METHOD OF PRODUCING MAGNETIC RECORDING TAPE

Magnetic Recording Mediam and Method of Manufacturing the Same

Magnetogrammträger mit geringer Neigung zu elektrostatischer Aufladung

MAGNETIC STORAGE MEDIUM WITH A BACKING LAYER CONTAINING CARBON BLACK

MAGNETIC TAPE, ITS CLEANING METHOD, AND OPTICAL SERVOTRACK FORMING/CLEANING APPARATUS

A magnetic tape which comprises a nonmagnetic support, a magnetic layer formed over one face of the nonmagnetic support, and a backcoat layer formed over the other face of the nonmagnetic support and containing a nonmagnetic powder with carbon black as one component and a binder, and which has an optical servotrack recess in the backcoat layer. This magnetic tape is characterized in that the mean value of the light reflectance of a flat part of the backcoat layer is 8.5% or more, and a maximum fluctuation in the light reflectance of the flat part with position of the magnetic tape: [maximum value of absolute value of (light reflectance) - (mean value of light reflectance) x 100/(mean value of light reflectance) is 10% or less. This tape has a high S/N ratio of a servosignal at the initial use and a high S/N ratio of the servosignal after two runs.

GLASS FOR USE AS SUBSTRATE FOR INFORMATION RECORDING MEDIUM, SUBSTRATE FOR INFORMATION RECORDING MEDIUM AND INFORMATION RECORDING MEDIUM, AND THEIR PRODUCTION METHODS

According to one aspect of the present invention, provided is glass for use in substrate for information recording medium, which comprises, denoted as molar percentages, a total of 70 to 85 percent of SiO2 and Al2O3, where SiO2 content is equal to or greater than 50 percent and Al2O3 content is equal to or greater than 3 percent; a total of equal to or greater than 10 percent of Li2O, Na2O and K2O; a total of 1 to 6 percent of CaO and MgO, where CaO content is greater than MgO content; a total of greater than 0 percent but equal to or lower than 4 percent of ZrO2, HfO2, Nb2O5, Ta2O5, La2O3 Y2O3 and TiO2; with the molar ratio of the total content of Li2O, Na2O and K2O to the total content of SiO2, Al2O3, ZrO2, HfO2, Nb2O5, Ta2O5, La2O3, Y2O3 and TiO2 ((Li2O+Na2O+K2O)/(SiO2+Al2O3+ZrO2+HfO2+Nb2O5+Ta2O5+La2O3+Y2O3+TiO2)) being equal to or less than 0.28. Further provided are the substrate for information recording medium, information recording medium and their manufacturing methods according ...

MAGNETIC RECORDING MEDIUM, MAGNETIC RECORDING AND REPRODUCING APPARATUS, MAGNETIC TAPE CARTRIDGE, AND MAGNETIC TAPE CARTRIDGE GROUP

In the magnetic recording medium, a number distribution A of a plurality of bright regions, based on equivalent circle diameters thereof, in a binarized image of a secondary electron image obtained by imaging a surface of the magnetic layer by a scanning electron microscope at an acceleration voltage of 5 kV and a number distribution B of a plurality of dark regions, based on equivalent circle diameters thereof, in a binarized image of a secondary electron image obtained by imaging a surface of the magnetic layer by a scanning electron microscope at an acceleration voltage of 2 kV respectively satisfy a predetermined number distribution.

Magnetic recording medium having a back coat layer containing carbon black treated with fatty acids

A magnetic recording medium comprises a back coat layer on one side of a non-magnetic support which is opposite to a side on which a magnetic recording layer has been formed. The back coat layer is made of a composition which comprises, in a resin binder, carbon black treated with a fatty acid of the formula, RCOOH, in which R represents a linear saturated or unsaturated hydrocarbon having from 13 to 17 carbon atoms. The medium is particularly suitable for high density recording.

Magnetic recording medium

A magnetic recording medium comprising a nonmagnetic flexible substrate, a magnetic layer provided on the surface of the substrate and containing ferromagnetic grains dispersed in a binder, and a back layer provided on the back surface of the substrate. The magnetic recording medium has a stiffness (STD) of 6.0 or less. The friction coefficient (μB) of the back layer surface with respect to the axial direction of a loading post in a video tape recorder is controlled to satisfy the condition: 0≦μB ≦0.1STD -0.05 so as to make the magnetic recording medium highly resistant to damage due to movement in a video tape recorder.

Magnetic recording medium

The method of improving a magnetic recording medium having a support, provided thereon a magnetic layer, and provided on an another side of the support a back coating layer, is disclosed. The improvement comprises the back coating layer containing a binder and a non-magnetic powder comprising essentially of a combination of carbon black and a non-magnetic particle selected from the group consisting of zinc oxide, titanium oxide, barium sulfate, ferric oxide and calcium carbonate.

Magnetic recording medium

There is provided a magnetic recording medium which comprises a substrate, a magnetic layer on one surface of a substrate and a backcoating layer on the other surface of the substrate, wherein the magnetic layer contains a magnetic metal powder having a major axis of not larger than 0.2 mu m and an inorganic powder having a Mohs' hardness of at least 5, and the backcoating layer contains an inorganic powder having a particle size smaller than the size of the major axis of the magnetic metal powder and which has sufficiently reduced noise at high density recording and high output required in, for example, a small size video tape with high picture quality, the magnetic recording medium in the form of a magnetic tape having a total thickness of not larger than 14 mu m inclusive of the substrate, the magnetic layer and the backcoating layer, and reliably maintained not to increase the noise after long term storage.

Magnetic recording medium and process for producing same

A magnetic recording medium having a thin magnetic film on a non-magnetic support base is disclosed. A layer of a compound which contains at least two isocyanate groups is formed in connection with the medium, and may be formed on either the surface of the metal film or the surface of the base opposite the metal film, or both. The resulting medium has excellent running properties, wear resistance and electro-to-magnetic conversion characteristics which are maintained after repeated use. The medium is formed by providing a non-magnetic support base surface and coating that surface with a thin magnetic metal film by use of a process such as vapor deposition. A solution of a compound containing at least two isocyanate groups is then applied to the medium within a solvent after which a heat treatment is carried out, thus forming the layer of compound containing the isocyanate groups.

MAGNETIC TAPE

Provided is a magnetic tape in which an Ra measured regarding a surface of a magnetic layer is equal to or smaller than 1.8 nm, Int(110)/Int(114) of a hexagonal ferrite crystal structure obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, a vertical squareness ratio of the magnetic tape is 0.65 to 1.00, the back coating layer includes one or more kinds of component selected from the group consisting of fatty acid and fatty acid amide, and a C—H derived C concentration calculated from a C—H peak area ratio of C1s spectra obtained by X-ray photoelectron spectroscopic analysis performed on the surface of the back coating layer at a photoelectron take-off angle of 10 degrees is equal to or greater than 35 atom %. 1. A magnetic tape comprising:a non-magnetic support;a magnetic layer including ferromagnetic powder, non-magnetic powder, and a binding agent on one surface side of the non-magnetic support; anda back coating layer including non-magnetic powder and a binding agent on the other surface side of the non-magnetic support,wherein the ferromagnetic powder is ferromagnetic hexagonal ferrite powder,a center line average surface roughness Ra measured regarding a surface of the magnetic layer is equal to or smaller than 1.8 nm,an intensity ratio Int(110)/Int(114) of a peak intensity Int(110) of a diffraction peak of a (110) plane with respect to a peak intensity Int(114) of a diffraction peak of a (114) plane of a hexagonal ferrite crystal structure obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0,a vertical squareness ratio of the magnetic tape is 0.65 to 1.00,the back coating layer includes one or more kinds of component selected from the group consisting of fatty acid and fatty acid amide, anda C—H derived C concentration calculated from a C—H peak area ratio of C1s spectra obtained by X-ray photoelectron spectroscopic analysis performed on the surface of ...

MAGNETIC RECORDING MEDIUM AND MAGNETIC RECORDING AND REPRODUCING DEVICE

Provided are a magnetic recording medium, in which a magnetic layer includes a ferromagnetic hexagonal ferrite powder, a binding agent, and an oxide abrasive, an intensity ratio Int(110)/Int(114) obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, a vertical squareness ratio of the magnetic recording medium is 0.65 to 1.00, a contact angle with respect to 1-bromonaphthalene measured regarding a surface of the magnetic layer is 50.0° to 55.0°, and an average particle diameter of the oxide abrasive obtained from a secondary ion image obtained by irradiating the surface of the magnetic layer with a focused ion beam is 0.04 μm to 0.08 μm, and a magnetic recording and reproducing device including this magnetic recording medium.

RECORDING DEVICE, READING DEVICE, RECORDING METHOD, RECORDING PROGRAM, READING METHOD, READING PROGRAM, AND MAGNETIC TAPE

An information processing device includes a generation unit that generates a hierarchy of a group that classifies each piece of data from information about each of a plurality of pieces of data to be recorded, and a control unit that controls recording of the plurality of pieces of data included in a group of the hierarchy at a highest level on a magnetic recording medium in a recording order according to an order from an upper hierarchy to a lower hierarchy, for each group of the hierarchy at the highest level. The magnetic recording medium has a magnetic layer containing a ferromagnetic powder and a binding agent on a non-magnetic support. A difference between spacings S0.5 and S13.5 measured under pressures of 0.5 atm and 13.5 atm by an optical interference method after n-hexane cleaning on a surface of the magnetic layer is equal to or less than 3.0 nm.

MAGNETIC TAPE, MAGNETIC TAPE CARTRIDGE, AND MAGNETIC TAPE DEVICE

Provided are a magnetic tape including a non-magnetic support and a magnetic layer including a ferromagnetic powder, a magnetic tape cartridge and a magnetic tape apparatus including this magnetic tape. An amount of a fluid lubricant collected by wiping a surface of the magnetic layer by a nonwoven fabric is in a range of 5 to 400 ng/m2as a value per unit area of the surface of the magnetic layer.

Magnetic tape having controlled dimensions, magnetic tape cartridge, and magnetic tape apparatus

The magnetic tape satisfies TDSage+TDSenv−TC≤0.30 μm. TDSage is a maximum absolute value of a difference between the servo band interval obtained before a predetermined storage and the servo band interval obtained after the storage, TDSenv is a value calculated by multiplying a difference between a maximum value and a minimum value of the servo band interval respectively obtained under five predetermined environments by ½, TC is a value calculated by multiplying TDStens by 0.5 N, and TDStens is a ratio of a change in the servo band interval to a change in tension calculated from the servo band interval respectively obtained under five predetermined environments by applying a plurality of different tensions in the longitudinal direction of the magnetic tape.

Magnetic recording medium

Disclosed is a magnetic recording medium good in production efficiency, paint stability and electromagnetic characteristics, and improved in running properties and durability, which has a magnetic layer formed on a surface side of a non-magnetic support and a backcoat layer formed on a back side thereof, in which said backcoat layer is formed by kneading a compounded composition comprising 50 parts to 120 parts by weight of carbon black (P) per 100 parts by weight of a resin binder (B) (P/B = 0.5/1 to 1.2/1), said carbon black (P) having an average particle size of 18 nm to 25 nm and a DBP oil absorption of 90 cc/100 g to 125 cc/100 g, 0.3 part to 2.5 parts by weight of large-sized carbon black or carbon graphite having an average particle size of 150 nm to 500 nm per 100 parts by weight of said carbon black, and a vinyl chloride copolymer as the resin binder, said copolymer containing at least amine-modified vinyl units and acidic functional group-containing vinyl units at the same time ...

Magnetic recording medium

The magnetic recording medium of this invention comprises a magnetic layer (10) formed on one (2a) of the opposite surfaces of a nonmagnetic support (2) and a backcoat layer (20) using a nonmagnetic powder and a binder as main components thereof and formed on the other surface (2b) thereof and uses as the binder in the backcoat layer a vinyl chloride-based copolymer having an amine-modified vinyl unit and an acidic functional group-containing vinyl unit. Owing to this construction, a paint to be used therein realizes perfect dispersibility and perfect stability. As a result, the backcoat layer to be formed therein is enabled to acquire excellent surface properties and the magnetic recording medium to be finally produced is allowed to exhibit an excellent electromagnetic conversion property. ...

Magnetic recording medium

MAGNETIC RECORDING MEDIUM

PURPOSE: To improve antistatic effect and durability by providing a back coat layer formed by dispersing conductive titanium oxide powder and carbon black into a resin binder on the other face of a nonmagnetic base having a magnetic layer on one face. CONSTITUTION: A magnetic coating compd. is dispersed by a ball mill and is coated on a PE terephthalate film. The film is then subjected to a calender treatment by which the magnetic layer is formed. A coating compd. prepd. by kneading and dispersing a back coating compd. in a ball mill and mixing polyisocyanate therewith is coated on the surface on the side opposite from the magnetic layer by which the back coat layer is formed. The magnetic recording medium which has the excellent antistatic effect and runnability of the back coat layer, obviates chipping of the back coat layer and the increase in output fluctuation and number of drop-outs and has the excellent durability is thereby obtd. COPYRIGHT: (C)1988,JPO&Japio ...

MAGNETIC TAPE

PROBLEM TO BE SOLVED: To provide a magnetic tape suitable for a magnetic recording and reproducing system in which a linear recording mode is utilized and a built-in magnetoresistive reproducing head is used. SOLUTION: The magnetic tape has a substantially nonmagnetic layer containing a nonmagnetic powder and a binder, and a magnetic layer containing a ferromagnetic powder and a binder, in this order on one face of the base and a back coat layer containing carbon black on the other face. The coefficient of thermal expansion of the magnetic tape in the width direction is ≤0.0015%/°C and the coefficient of moisture expansion is ≤0.0015%/%RH. The offset yield strength of the magnetic tape in the longitudinal direction is ≥10N and the break-down strength is ≥30N. The number of projections being present on the surface of the magnetic layer of the magnetic tape and having ≥50 nm height and a height to width ratio of ≤0.02 is ≤6 per 1 cm2. COPYRIGHT: (C)2002,JPO ...

BACK COATING MATERIAL FOR MAGNETIC RECORDING MEDIUM

PURPOSE: To obtain the back-coating material capable of utilizing an UV-curing method and of easily curing a film in an air without the curing inhibition by oxygen, by incorporating an antistatic agent, a lubricant and a compd. capable of generating a Lewis acid by irradiating a light to an epoxy resin having at least two of the epoxy groups in a molecular. CONSTITUTION: The epoxy resin having at least two of epoxy groups in the molecular comprises a glycidyl ether of aromatic phenol such as 2,2'-bis(P- hydroxy phenyl) propane. The epoxy resin may be used independently or in a combination thereof. The antistatic agent comprises a solid antistatic agent usable to an ordinary magnetic recording tape, such as a carbon black. The compounding amount of the antistatic agent is preferably added 5W50pts.wt. to the epoxy resin from the antistatic effect of the cured material point of view. In such a way that the surface resistance of the titled back-coating mate rial makes ≤1012Ω/square. The dispersion ...

MAGNETIC RECORDING MEDIUM

PURPOSE: To enhance the physical property, wear resistance, toughness, and filler retaining property of the backcoat layer and to prevent the deformation of a tape and generation of abnormality in repeated traveling by incorporating zinc oxide having a single-peak distribution of particles having specified diameter into nonmagnetic powder. CONSTITUTION: A magnetic layer is provided on one surface of a carrier, and the backcoat layer contg. a binder and nonmagnetic powder is furnished on the other surface. The powder contg. zinc oxide and contg. 10W50wt% of particles having ≥0.5μ diameter and 60W1wt% of particles having ≤0.15μm diameter in a single-peak distribution is used as the nonmagnetic powder. The polyurethane resin to be used in the backcoat layer is synthesized by the reaction of a polyol with a polyisocyanate. Consequently, the traveling stability of the medium under high-temp. and high-humidity conditions can be improved. COPYRIGHT: (C)1987,JPO&Japio ...

MAGNETIC TAPE

PROBLEM TO BE SOLVED: To provide a magnetic tape which has excellent electromagnetic transducing characteristics and traveling durability even in the case of forming the magnetic tape to have a relatively small thickness over the entire part and thickness of a back coating layer, has high reliability to recording and reading out of data, and is useful as the magnetic tape for computer. SOLUTION: The back coating layer of the magnetic tape consisting of a nonmagnetic base, a magnetic layer and the back coating layer having the thickness of 0.2 to 0.8μm and the total thickness of 3 to 10μm contains particulate carbon black having an average particle size of 10 to 20μm and coarse particulate carbon black having an average particle size of 230 to 300μm. Further, the back coating layer contains calcium carbonate having an average particle size of 30 to 50μm and an inorg. powder having an average particle size of 80 to 250μm and Mohs hardness of 5 to 9 and the surface roughness Ra thereof is ...

MAGNETIC RECORDING MEDIUM

PROBLEM TO BE SOLVED: To provide a magnetic tape suitable for using to a recording/ reproducing device of a non-tracking system. SOLUTION: In a tape like magnetic recording medium having a magnetic layer of a metallic magnetic thin film on a non-magnetic supporting body, when the frictional coefficient of the magnetic surface of the magnetic recording medium is defined μ1, and the frictional coefficient of a non-magnetic surface is μ2, the ranges of μ1 and μ2 are made 0.15≤μ1≤0.30, and 0.20≤μ2≤0.40. By respectively setting the frictional coefficients of the magnetic surface and the non-magnetic surface of the magnetic tape 3 in the ranges, a strike between the tape and a guide at a tape 3 running time becomes excellent, and an error rate when information is recorded/reproduced is improved. Lubricant 4 is applied by holding in the magnetic tape 3 between a roll 1 controlling its surface property and the roll 2 arranged oppositely to the roll 1 and with a size smaller than the roll 1, and ...

MAGNETIC RECORDING MEDIUM

PURPOSE: To inhibit the charging, to improve the running stability and to reduce the output change by laying a coated film contg. powder of a specified quat. ammonium salt optionally together with a fatty acid on the back side of a substrate having a magnetic layer. CONSTITUTION: A coated film contg. powder of a quat. ammonium salt represented by the general formula optionally together with a fatty acid is laid on the back side of a substrate for forming a magnetic layer. The preferred ammonium salt has a bivalent phenyl group having no substituent as Z, 1 as n and Cl as X in the formula or O as Z, 2 as n and Cl as X, and the preferred average particle size of the ammonium salt is ≤5μm. The thickness of the coated film is generally regulated to about 0.05W5μm, and vinyl chloride-vinyl acetate copolymer resin or the like is used as a binder for forming the coated film on the substrate. COPYRIGHT: (C)1983,JPO&Japio ...

MAGNETIC RECORDING MEDIUM FOR VIDEO

PURPOSE: To enhance long wavelength recording characteristics and to prevent the generation of missing, etc. of voice recording by incorporating magnetic powders having specific surface areas into respective plural magnetic layers and specifying the relations between the film thicknesses and respective coercive forces of the magnetic layer on the extreme surface among these magnetic layers and the other magnetic layer. CONSTITUTION: The magnetic powder having ≥30m2/g and ≤80m2/g specific surface area in BET value are incorporated into the respective plural magnetic layers. The film thickness of the magnetic layer on the extreme surface among the plural magnetic layers is specified to ≥0.1μm and ≤1.5μm and the magnetic layer having the coercive force larger by ≥50 ersted than the coercive force of the magnetic layer on the extreme surface is provided. This magnetic layer is so formed as to have ≥1.5μm and ≤3.0μm film thickness. The short wave length recording is, therefore, executed by the ...

MAGNETIC RECORDING MEDIUM

PROBLEM TO BE SOLVED: To enable a magnetic recording medium improved in storage efficiency under bad environments, by forming a metallic anti-corrosive layer to an opposite face on a non-magnetic supporting body to a face where a magnetic layer is formed, and restricting a chemical change caused at the non-magnetic supporting body to a minimum. SOLUTION: A metallic anti-corrosive layer 3 is formed at an opposite face on a non-magnetic supporting body of a polymer film 1 to a face where a magnetic layer 2 is formed. The metallic anti-corrosive layer 3 has a thickness of 0.01-0.7 μm. A metal having low moisture permeability and gas permeability and high barrier effect is selected for the metallic anti-corrosive layer 3, so that storage efficiency under severe environments can be improved greatly. For example, a multilayered film of copper-nickel alloy, an alloy including at least one of copper and nickel, or many layers is used as the metallic anti-corrosive layer 3. The metallic anti-corrosive ...

MAGNETIC RECORDING MEDIUM

PURPOSE: To improve the S/N of a signal at and under a wide range of temp. and humidity by forming a thin ferromagnetic metallic film and resin layer contg. pulverized metallic particles on the surface of a high-polymer film. CONSTITUTION: The thin ferromagnetic metallic film 7 and a vacuum deposited film 8 consisting of a perfluorooctanoic acid are formed on one face of the high-polymer film 6 consisting of a PE terephthalate. A metal-contg. coating layer 9 contg. pulverized aluminum particles 10 in an urethane resin 11 is formed on the other face. Such magnetic tape is subjected to recording and reproducing by a metal-in gap type ring head formed by sputtering a 'SendustÅ' alloy near a gap, by which the good S/N is obtd. COPYRIGHT: (C)1987,JPO&Japio ...

MAGNETIC RECORDING MEDIUM

PURPOSE: To provide a magnetic recording medium having high durability even when used at the interior and exterior of a house over a long period of time and especially useful in practical use. CONSTITUTION: When a magnetic layer contg. at least magnetic powder and a resin binder is formed on a nonmagnetic substrate to obtain a magnetic recording medium, anitmold powder obtd. by carrying a mildew-resistant metal on the surface of powder insoluble in an org. solvent is incorporated into he magnetic layer or into the magnetic layer and/or a back coat layer in the case where the back coat layer is formed on the rear side of the nonmagnetic substrate. The resulting magnetic recording medium can satisfactorily maintain its magnetic characteristics and mechanical strength while exhibiting an antimold effect even in an environment at high temp. and humidity. COPYRIGHT: (C)1994,JPO ...

MAGNETIC RECORDING MEDIUM

PROBLEM TO BE SOLVED: To provide a magnetic recording medium attaining excellent electromagnetic transducing characteristics and running stability, maintaining a high S/N and having reduced dropout and a low error rate. SOLUTION: In the magnetic recording medium having a non-magnetic layer and a magnetic layer on one surface of a non-magnetic supporting body and back coat layer on the other surface, the back coat layer has 65 to 95°C Tg and a binder which constitutes the back coat layer satisfies the following conditions. (1) The binder consists essentially of a vinyl chloride resin PVC and a polyurethane resin PU. (2) The PVC has a solubility parameter of 9 to 11, 65 to 95°C Tg and Mw of 5,000 to 25,000. (3) The binder has 10 to 60 mass% PVC to the total PVC and PU. (4) The PU has a solubility parameter of 9.5 to 11.5, 80 to 110°C Tg and Mw of 20,000 to 60,000. (5) The binder has 90 to 30 mass% PU to the total PVC and PU. COPYRIGHT: (C)2008,JPO&INPIT ...

MAGNETIC RECORDING MEDIUM

PURPOSE: To maintain a good S/N ratio under various environmental conditions by providing a thin ferromagnetic metallic film on one face of a high-polymer film, forming a vapor deposited film having 0.3W0.7 filling factor on the other face and disposing a lubricant on both faces. CONSTITUTION: The thin ferromagnetic metallic film 6 consisting of a Co-O film having 0.12μm thickness is provided on one face of the high-polymer film 5 consisting of a polyethylene naphthalate having 9μm thickness and the vapor deposited Ni film 7 having 0.3W0.7 filling factor is formed on the other face. The lubricant layers 8, 9 consisting of a stearic acid are formed on both these faces by a both-faces vapor deposition method. Since the lubricant is disposed on both the faces, the starvation of the lubricant during the use in a winding state is obviated. Since the filling factor is adequately set, the output fluctuation is surely prevented. The good S/N ratio is thus maintained even if the medium is used under ...

PRODUCTION OF BASE FOR MAGNETIC RECORDING MEDIUM

PURPOSE: To form the more uniform and smoother image plane by coating an under coating liquid contg. a radiation crosslinking type stock and fine particles simultaneously on both faces and curing the coating by radiations. CONSTITUTION: The under coating liquid 6 contg. the radiation crosslinking type stock and the fine particles is simultaneously coated on both faces of a nonmagnetic base and is cured by the radiations 9. The radiation crosslinking type stock is a compd. which can be polymerized by the irradiation of the radiations. Said stock is preferably a (meth)acrylate compd. contg. a triazine ring. Fine silica particles introduced from a silica sol are used as the fine particles. Since the simultaneous coating on both faces and the electron ray irradiation are executed in such a manner, the base which is smooth and is uniform in the surface roughness of both faces is obtd. even in the case of the short-sized nonmagnetic base. COPYRIGHT: (C)1989,JPO&Japio ...

MAGNETIC RECORDING MEDIUM

PURPOSE: To improve the electromagnetic transducing characteristic and light transmissivity of the titled medium by providing a magnetic layer on one surface of a carrier and forming a layer contg. specified carbon black and fatty acid- modified organosilicon on the other surface. CONSTITUTION: A layer contg. carbon black is provided as a back-coat layer on the surface of a carrier opposite to the surface on which a magnetic layer is formed. Carbon black having about 2.0W8.5pH and ≥about 90 tinting power by the ASTM method is used as the carbon block to be incorporated into the back-coat layer. About 25W400pts.wt. carbon black having about 0.01W0.05μm particle diameter and about 0.5W4.5pts.wt. fatty acid-modified organosilicon are incorporated into 100pts.wt. binder to form the back-coat layer. Consequently, the electromagnetic transducing characteristic is improved and the light transmittance is reduced. COPYRIGHT: (C)1986,JPO&Japio ...

MAGNETIC RECORDING MEDIUM

PURPOSE: To avoid such problems that the surface property of a magnetic layer or back coating layer deteriorates because of high hardness binder resin in a magnetic recording medium used for such as audiotape, video tape, and magnetic disk and that electromagnetic characteristics deteriorate, and to obtain a magnetic tape having high surface property of a back coating layer and having high output and excellent durability. CONSTITUTION: This magnetic recording medium consists of a magnetic layer on one surface of a nonmagnetic supporting body and a back coating layer on the other surface. An intermediate layer containing a planer inorg. powder material and granular inorg. powder material is formed between the nonmagnetic supporting body and the magnetic layer, or between the nonmagnetic supporting body and the back coating layer, or both of these. COPYRIGHT: (C)1993,JPO&Japio ...

Фрикционный слой носителя магнитной записи

Magnetic tape cassette for audio, video or computer use - has magnetic tape formed from material having thermal shrinkage of 0.6 per cent and min. 300 windings on spool

The magnetic tape is designed to provide a good thermal resistance characteristic with a small thermal shrinkage coefficient. The tape is produced with a base foil of polyethyleneenterephlate that is heat treated before a surface coating is formed. The coating is produced from needle shaped Fe powder combined with vinyl chloride resin, urethane resin, polyisocyanate, butylstearate, cyclohexanon, methylethylceton and toluol. The film formed is 3 micron thick and is dried and calenderised. USE/ADVANTAGE - For high quality reproduction of recordings. Suitable for high temperature operation.

Magnetic recording material

A magnetic recording material is proposed which comprises a non-magnetic base with a magnetic layer formed thereupon and, on the opposite surface of the same, a backing layer of a thickness of 2 mu m or less which contains an inorganic powder and a binder, the average particle size of the inorganic powder being 0.02 to 0.5 mu m, the Mohs' hardness being 2.5 or more and the surface roughness of the backing layer, specified as the average centre-line roughness (Ra) in the section from 0.08 mm, being 0.025 to 0.1 mu m.

Magnetische Aufzeichnungsträger

MAGNETISCHES AUFZEICHNUNGSMATERIAL

Magnetisches Aufzeichnungsmedium

Magnetogrammtraeger mit verminderter Neigung zu elektrostatischer Aufladung

Magnetic recording medium having a rear coating of carbon black in a vinyl alcohol/vinyl chloride resin

The invention relates to a magnetic recording medium which contains a nonmagnetic base (support), a magnetic recording layer formed on one side of the nonmagnetic base, and a rear coating formed on the other side. According to the invention, the rear coating is produced from a composition in which carbon black is dispersed in a vinyl alcohol/ vinyl chloride resin having a vinyl chloride content of not less than ..% by weight. Since the resin has good compatibility with carbon black, the magnetic recording medium has improved properties.

MAGNETISCHES AUFZEICHNUNGSMATERIAL

Magnetisches Aufzeichnungsmaterial

Recording media

MAGNETIC TAPE CARTRIDGE

MAGNETISABLE RECORDING TAPES

... 1530911 Magnetic recording tapes EMI Ltd 22 Jan 1976 [22 Jan 1975] 2727/75 Heading B2E A multi-layer record tape structure has a base layer with, on opposite surfaces, a magnetisable recording layer comprising an evaporated film of a metal or alloy and an additional base layer, comprising a plastics loaded with a magnetically inert pigment and of uniform thickness greater than that of the recording layer. The recording material may be an evaporated film of a metal or an alloy. The additional layer may be of plastics material which may be loaded with pigment such as iron oxide, talc, carbon or titanium dioxide. Preferably the binder is a polyvinylidene chloride/polyurethane system or a polyvinyl chloride/polyester system. Preferably the base is of polyethylene terephthalate.

METHOD OF PRODUCING MAGNETIC RECORDING TAPE

... 1381869 Producing coated magnetic tapes FUJI PHOTO FILM CO Ltd 14 Dec 1971 [15 Dec 1970] 58128/71 Heading B2E In a method of producing a magnetic recording tape, a 3-ply starting material is calendered through a space between a metal roller and a non-metal roller so that a magnetic layer on one surface of the base makes contact with the metal roller and a layer of greater resilience than the base makes contact with the non-metallic roller whereby surface irregularities in the non-metallic roller are compensated for and a uniform pressure between the magnetic layer and the metal roller yields a smooth magnetic surface on the tape. The resilient layer is preferably applied to the back of a magnetic tape, may be porous and consist of polyurethane containing carbon black. Alternatively it may consist of TiO 2 in synthetic rubber e.g. chlorosulphonated polyethylene. Copolymers such as ethylene-vinyl acetate copolymer mixtures may provide the resilient layer and vinyl chloride-acetate mixtures ...

MAGNETIC RECORDING MEDIUM

Magnetic recording medium

Disclosed herein is a magnetic recording medium comprising a substrate polyester film having on both sides or one side thereof a coating layer comprising a polyurethane having anionic group or a mixture of a polyurethane having anionic group and a polyester having sulfonic group, and an electron radiation cured magnetic layer formed on said coating layer.

Antistatic magnetic recording tapes

The invention provides a novel means for solving and overcoming the problems in the magnetic recording tapes caused by the accumulation of static electricity during travelling of the tape affecting the quality of the reproduced sounds and picture images by playing the tape. The inventive method comprises providing at least one surface of the plastic-made film base with a layer of a plasma-polymerized gaseous compound of a specific type by exposing the surface of the film base to the atmosphere of low temperature plasma generated in the low pressure atmosphere of the gas or vapor of a compound such as an amine, organosilane, aliphatically unsaturated compound and aromatic compound, preferably, before coating the film base with a magnetic coating composition. The plasma-polymerized layer is effective to decrease the surface resistivity of the film base and to reduce the accumulation of static electricity induced by rubbing.

MAGNETIC RECORDING MEDIUM

Method of making a magnetic recording medium

To make a magnetic recording medium which will not curl at the edges, a non-magnetic support such as polyethylene terephthalate is coated (a) on one surface with a magnetic coating composition, and (b) on the other (rear) surface with an unsatured compound which is polymerizable by electron beams; the material is irradiated, e.g. from a curtain beam accelerator, at 100 to 1,000 Kv with electron beams at an absorbed dose of 0.5 to 20 megarads so as to polymerize the compound. Suitable polymerizable compounds have at least two -C=C- bonds, e.g. unsaturated polyesters having an acryloyl, acrylamido, allyl, vinyl ether or vinyl thioether group; preferably it has a meth(acryloyl) group on both ends of its straight chain. The magnetic coating may be of ferromagnetic particles also in a compound polymerizable by electron beams, which is irradiated separately or at the same time as the rear coating. An unsaturated -C=C- monomer and/or a thermoplastic resin may also be present in the rear coating ...

MAGNETIC TAPE AND MAGNETIC TAPE CARTRIDGE

MAGNETIC RECORDING MEDIUM

MAGNETIC TAPE

A magnetic tape characterized in that recesses (10) which have predetermined shapes so as to be able to produce contrast optically are formed in the surface of a backcoat layer (5) to enable the servotracking of the data tracks of a magnetic layer in accordance with optical information from the recesses, each recess (10) has a depth of 0.05-1 μm and a width of 0.25-30 μm, and the backcoat layer (5) has an arithmetical average surface roughness Ra of 4-20 nm.

Single reel magnetic tape cartridge with pre-defined tape width difference

Provided is a magnetic tape cartridge of a single reel type in which a magnetic tape is wound around a reel, in which the magnetic tape includes a non-magnetic support, and a magnetic layer including a ferromagnetic powder and a binding agent on the non-magnetic support, a tape thickness is equal to or smaller than 5.2 μm, a tape width difference (B−A) between a tape width A at a position of 10 m±1 m from a tape outer end and a tape width B at a position of 50 m±1 m from a tape inner end is 2.4 μm to 12.0 μm, and the tape width A and the tape width B are values measured 100 days from the date of magnetic tape cartridge manufacture.

Magnetic recording layer

A magnetic recording medium comprising a backcoating layer, a support, and a magnetic layer containing ferromagnetic powder, the backcoating layer having 800 to 1500 projections of 50 nm or more and less than 75 nm in height per 6400 mum² and 600 or less projections of 75 nm or more in height per 6400 mum².

Magnetic recording medium

A magnetic recording medium is disclosed which comprises a non-magnetic support, having a Young's modulus of 7x1010 to 1x1013 dyn/cm2, having coated on opposite surfaces, a magnetic recording layer comprising ferromagnetic particles and a fatty acid ester and a backing layer comprising a cellulose resin.

Magnetic recording tape

A magnetic recording tape comprising: a magnetic layer comprising a ferromagnetic powder and a binder; a nonmagnetic layer; a support; and a back coating layer, in this order, wherein the magnetic layer comprises, as the binder, a polyurethane resin comprising a dimer diol as a diol component, the back coating layer comprises nonmagnetic inorganic powders and from 1 to 5 parts by weight, based on 100 parts by weight of a total amount of the nonmagnetic inorganic powders, of a lubricant, and a number of protrusions having a height, as measured by an atomic force microscope, of from 30 to 100 nm present on a surface of the back coating layer is from 10 to 1,000 per a 90-mum square.

Magnetic tape cartridge

A magnetic tape cartridge comprising a magnetic tape suitable for long time recording which has a coefficient of thermal shrinkage of 0.6% or less the coefficient being measured after the tape is wound around a hub at least 300 turns and kept at 105 DEG C. for 30 minutes.

Magnetic recording medium

The present invention provides a magnetic recording medium, in particular a linear recording tape for use with computers, comprising a back coat layer with proper strength and having excellent electromagnetic conversion characteristics and excellent running durability. The magnetic recording medium comprises a lower non-magnetic layer on one surface of a non-magnetic support, an upper magnetic layer on the lower non-magnetic layer, and the back coat layer on the other surface of the non-magnetic support. And the magnetic layer has a SENDUST abrasion volume SMC of 3.0x10<4>(mum)<3>/m or less and a ratio (SBC/SMC) of a SENDUST abrasion volume SBC by the back coat layer to the SENDUST abrasion volume SMC by the magnetic layer is in the range of 0.5 to 3.0.

MAGNETIC TAPE

Provided is a magnetic tape in which ferromagnetic powder included in a magnetic layer is ferromagnetic hexagonal ferrite powder having an activation volume equal to or smaller than 1,600 nm, the magnetic layer includes one or more components selected from the group consisting of fatty acid and fatty acid amide, and an abrasive, a C—H derived C concentration calculated from a C—H peak area ratio of C1s spectra obtained by X-ray photoelectron spectroscopic analysis performed on the surface of the magnetic layer at a photoelectron take-off angle of 10 degrees is equal to or greater than 45 atom %, and a tilt cos θ of the ferromagnetic hexagonal ferrite powder with respect to the surface of the magnetic layer acquired by cross section observation performed by using a scanning transmission electron microscope is 0.85 to 1.00. 1. A magnetic tape comprising:a non-magnetic support; anda magnetic layer including ferromagnetic powder and a binder on the non-magnetic support,{'sup': '3', 'wherein the ferromagnetic powder is ferromagnetic hexagonal ferrite powder having an activation volume equal to or smaller than 1,600 nm,'}the magnetic layer includes one or more components selected from the group consisting of fatty acid and fatty acid amide, and an abrasive,a C—H derived C concentration calculated from a C—H peak area ratio of C1s spectra obtained by X-ray photoelectron spectroscopic analysis performed on the surface of the magnetic layer at a photoelectron take-off angle of 10 degrees is equal to or greater than 45 atom %, anda tilt cos θ of the ferromagnetic hexagonal ferrite powder with respect to the surface of the magnetic layer acquired by cross section observation performed by using a scanning transmission electron microscope is 0.85 to 1.00.2. The magnetic tape according to claim 1 ,wherein the C—H derived C concentration is 45 atom % to 80 atom %.3. The magnetic tape according to claim 1 ,wherein the C—H derived C concentration is 50 atom % to 80 atom %.4. The ...

Magnetic tape having servo pattern and characterized magnetic layer, and magnetic tape device

The magnetic tape includes a non-magnetic support; and a magnetic layer including a ferromagnetic powder and a binding agent on the non-magnetic support, in which a magnetic tape total thickness is equal to or smaller than 5.30 μm, the magnetic layer has a servo pattern, a center line average surface roughness Ra measured regarding a surface of the magnetic layer is equal to or smaller than 1.8 nm, and an isoelectric point of a surface zeta potential of the magnetic layer is equal to or greater than 5.5.

Styrene-based resin composite material and use thereof

MAGNETIC RECORDING MEDIUM

PURPOSE: To reduce frictional force to improve a running characteristic by forming a magnetic layer on the surface of a nonmagnetic base material and by forming an applied film including an interface activator of an HLB 8.0 or less and an interface activator of an HLB 8.0 or more on the surface of the magnetic layer or the reverse face of the base material. CONSTITUTION: An applied liquid including a binder such as vinylidene chlorideacrylic acid ester where an interface activator (such as sorbitan tristearate) of an HLB value (indicating balance between an affinity property for water and an affinity property for oil), which is obtained by the Davies method, 8.0 or less and interface acitvator (such as polyoxyethylene lauryl ether) of an HLB value 8.0 or more of several % are included is applied onto a magnetic layer provided on a support material film such as polyester or onto the face of the support material opposite to the magnetic layer. By the synergistic effect of the lubricant action ...

MAGNETIC RECORDING MEDIUM

PROBLEM TO BE SOLVED: To improve the characteristics of a magnetic coating material as a coating material, to reduce error rate and to improve durability as well as to increase output by using specified compds. as a binder and a curing agent in a magnetic layer. SOLUTION: A magnetic layer 4 positioned on a middle layer 3 in this magnetic recording medium 1 is the top layer of the medium, that is, a layer positioned at the surface of the medium and is formed by coating the top of the middle layer 3 with a magnetic coating material contg. linear polyurethane having at least two isocyanato groups in one molecule and a number average mol.wt. of 3,000-40,000 as a curing agent as well as magnetic powder, carbon powder (carbon black),,inorg. particles having a Mohs hardness of ≥8, fatty acid, fatty acid ester, a binder and an amine compd. COPYRIGHT: (C)1998,JPO ...

MAGNETIC RECORDING MEDIUM

PROBLEM TO BE SOLVED: To provide a magnetic recording medium which is excellent in running stability and durability and is optimum for high density magnetic recording by prescribing impregnation quantity of lubricant impregnating in a back coat layer in a magnetic recording medium in which recording and reproducing of signals are performed by a linear system. SOLUTION: This medium is a magnetic recording medium 10 in which a plurality of tracks are provided in parallel to a longitudinal direction and recording and reproducing of signals are performed by a linear system, the medium 10 has a non-magnetic supporting body 1 extended in the longitudinal direction, a magnetic layer 3 in which a plurality of magnetic films 3a, 3b having an orthorhombic prism type structure are laminated and formed, a growth direction of laminated each magnetic film 3a, 3b is inverse direction to the longitudinal direction, and a back coat layer 6 which is formed at the other plane of the non-magnetic supporting ...

ANTISTATIC FILM

PURPOSE: To obtain an antistatic film excellent in antistatic properties, adhesive properties, resistance to transfer to the back side, and antiblocking properties. CONSTITUTION: This antistatic film. used for a magnetic card, comprises a polyester film and an antistatic coating layer which is formed on at least one side of the film by applying a water-base coating fluid contg. a compsn. comprising 1-40wt.% antistatic polymer obtd. by polymerizing pyrrole and/or its deriv. and 60-99wt.% at least one binder resin having a second order transition temperature of 40-100°C and selected from among a polyester resin, an acrylic resin, an acrylic-modified polyester resin, and a urethane resin. COPYRIGHT: (C)1996,JPO ...

CONTINUOUS MAGNETIC THIN-FILM MEDIUM

PURPOSE: To improve durability by superposing and laminating the surfaces, which are not formed with a magnetic layers and carbon black layer, of a polyimide film formed with the magnetic layer on one surface and a specific high-polymer film formed with the carbon black layer on one surface on each other. CONSTITUTION: The high-polymer film 5 having resilience and 300 to 500kgf/mm2 modulus of elasticity is used on a pad side to disperse the pressure from the rear surface of the continuous medium 7, by which the durability is improved and the generation of scratches on the magnetic layer 2 formed on the other surface is prevented in spite of intrusion of dust to the one surface. The adsorption of the dust is prevented by the prevention of the triboelectrostatic charge by the rotation in contact with the pad and the traveling stability of the continuous medium 7 is held if the carbon black layer 6 is formed on the high-polymer film 5 which is on the rear side of the magnetic layer 2. The ...

MAGNETIC TAPE

PROBLEM TO BE SOLVED: To provide a magnetic tape adaptive for a magnetic recording and reproducing system capable of high density recording, exhibiting excellent electromagnetic transducing characteristic, handling property and traveling durability and particularly advantageous for recording computer data. SOLUTION: The magnetic tape has a magnetic layer containing ferromagnetic powder and a binder on one surface of a long-length support and a back coat layer containing carbon black and a binder on another surface of the long-length support, is 3-10 μm in the total thickness and is constituted so that the radius of curvature of curl of the magnetic tape in the longitudinal direction is ≥10 mm and the curl of the tape in the width direction is curved projectingly to the magnetic layer side and the radius of curvature is ≥40 mm. A magnetic tape provided with a non-magnetic layer between the support and the magnetic layer has the same constitution. COPYRIGHT: (C)2000,JPO ...

MANUFACTURING METHOD OF GLASS BLANK FOR MAGNETIC DISK, MANUFACTURING METHOD OF GLASS SUBSTRATE FOR MAGNETIC DISK, GLASS BLANK FOR MAGNETIC DISK, GLASS SUBSTRATE FOR MAGNETIC DISK, AND MAGNETIC DISK

To provide a method for manufacturing a glass blank for magnetic disk and a method for manufacturing a glass substrate for magnetic disk, which are capable of producing a glass blank for magnetic disk having a good surface waviness by press forming, and a method for manufacturing a glass substrate for magnetic disk. A method for manufacturing a glass blank for magnetic disk, which includes a forming process of press-forming a lump of molten glass using a pair of dies, wherein in the forming process, press forming is performed using thermally equalizing means for reducing a difference in temperature in the press forming surface of the die during pressing of the molten glass. 1. A method for manufacturing a glass blank for magnetic disk , the method comprising a forming process of press-forming a lump of molten glass using a pair of dies to obtain a sheet glass material , wherein in the forming process , a difference in temperature in a press forming surface of the die is controlled so that the surface waviness of the sheet glass material is equal to 30 nm or less.2. The method for manufacturing a glass blank for magnetic disk according to claim 1 , wherein thermally equalizing means reduces the difference in temperature in the press forming surface by heat-exhausting from the press forming surface and/or heating the press forming surface.3. The method for manufacturing a glass blank for magnetic disk according to claim 1 , wherein the thermally equalizing means is a heat sink.4. The method for manufacturing a glass blank for magnetic disk according to claim 3 , wherein the heat sink is provided on at least a part of the surface opposite to the press forming surface.5. The method for manufacturing a glass blank for magnetic disk according to claim 4 , wherein the heat sink is provided so that amount of heat exhausted from a central portion of the molten glass is larger than that from the circumferential edge portion of the molten glass during the press forming.6. The ...

MAGNETIC RECORDING MEDIUM

The average thickness tof a magnetic recording medium meets the requirement that t≤5.5 [μm], and the dimensional change amount Δw in the width direction of the magnetic recording medium with respect to the tension change in the longitudinal direction of the magnetic recording medium meets the requirement that 700 ppm/N≤Δw. 2. The magnetic recording medium according to claim 1 , wherein the dimensional change amount Δw satisfies 750 ppm/N≤Δw≤8000 ppm/N.3. The magnetic recording medium according to claim 1 , wherein the dimensional change amount Δw satisfies 800 ppm/N≤Δw≤8000 ppm/N.4. The magnetic recording medium according to claim 1 , whereina temperature expansion coefficient α of the magnetic recording medium satisfies 6 ppm/° C.≤α≤8 ppm/° C., anda humidity expansion coefficient β of the magnetic recording medium satisfies β≤5 ppm/% RH.5. The magnetic recording medium according to claim 1 , wherein a Poisson's ratio ρ of the magnetic recording medium satisfies 0.3≤ρ.6. The magnetic recording medium according to claim 1 , wherein an elastic limit value σin the longitudinal direction of the magnetic recording medium satisfies 0.8 N≤σand the elastic limit value σdoes not depend on a rate V in elastic limit measurement.7. The magnetic recording medium according to claim 1 , wherein an arithmetic mean roughness Ra of a magnetic surface of the magnetic recording medium is 2.0 nm or less.8. The magnetic recording medium according to claim 1 , further comprisinga magnetic surface and a back surface on an opposite side to the magnetic surface, whereinan interlayer friction coefficient μ between the magnetic surface and the back surface satisfies 0.20≤μ≤0.80.9. The magnetic recording medium according to claim 1 , wherein the squareness ratio in the perpendicular direction of the magnetic recording medium is 73% or more.10. The magnetic recording medium according to claim 1 , wherein a ratio R (=Hc(50)/Hc(25)*100) between a coercive force Hc (50) measured in a perpendicular ...

MAGNETIC TAPE AND MAGNETIC TAPE DEVICE

The magnetic tape includes: a non-magnetic support; a non-magnetic layer including non-magnetic powder and a binding agent on the non-magnetic support; and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic layer, in which a total thickness of the non-magnetic layer and the magnetic layer is equal to or smaller than 0.60 μm, the magnetic layer has a servo pattern, the ferromagnetic powder is ferromagnetic hexagonal ferrite powder, an intensity ratio of a peak intensity of a diffraction peak of a () plane with respect to a peak intensity of a diffraction peak of a () plane of a hexagonal ferrite crystal structure obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, and a vertical direction squareness ratio of the magnetic tape is 0.65 to 1.00, and a magnetic tape device including this magnetic tape. 1. A magnetic tape comprising:a non-magnetic support;a non-magnetic layer including non-magnetic powder and a binding agent on the non-magnetic support; anda magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic layer,wherein a total thickness of the non-magnetic layer and the magnetic layer is equal to or smaller than 0.60 μm,the magnetic layer has a servo pattern,the ferromagnetic powder is ferromagnetic hexagonal ferrite powder,an intensity ratio Int(110)/Int(114) of a peak intensity Int(110) of a diffraction peak of a (110) plane with respect to a peak intensity Int(114) of a diffraction peak of a (114) plane of a hexagonal ferrite crystal structure obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, anda vertical direction squareness ratio of the magnetic tape is 0.65 to 1.00.2. The magnetic tape according to claim 1 ,wherein the vertical direction squareness ratio of the magnetic tape is 0.65 to 0.90.3. The magnetic tape according to claim 1 ,wherein the total thickness of the non-magnetic ...

MAGNETIC TAPE AND MAGNETIC TAPE DEVICE

Provided are a magnetic tape including: a non-magnetic support; and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, in which the magnetic layer has a timing-based servo pattern, a center line average surface roughness Ra measured regarding a surface of the magnetic layer is equal to or smaller than 1.8 nm, the ferromagnetic powder is ferromagnetic hexagonal ferrite powder, an intensity ratio of a peak intensity of a diffraction peak of a (110) plane with respect to a peak intensity of a diffraction peak of a (114) plane of a hexagonal ferrite crystal structure obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, and a vertical direction squareness ratio of the magnetic tape is 0.65 to 1.00, and a magnetic tape device including this magnetic tape. 1. A magnetic tape comprising:a non-magnetic support; anda magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support,wherein the magnetic layer has a timing-based servo pattern,a center line average surface roughness Ra measured regarding a surface of the magnetic layer is equal to or smaller than 1.8 nm,the ferromagnetic powder is ferromagnetic hexagonal ferrite powder,an intensity ratio Int(110)/Int(114) of a peak intensity Int(110) of a diffraction peak of a (110) plane with respect to a peak intensity Int(114) of a diffraction peak of a (114) plane of a hexagonal ferrite crystal structure obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, anda vertical direction squareness ratio of the magnetic tape is 0.65 to 1.00.2. The magnetic tape according to claim 1 ,wherein the vertical direction squareness ratio of the magnetic tape is 0.65 to 0.90.3. The magnetic tape according to claim 1 ,wherein the center line average surface roughness Ra measured regarding the surface of the magnetic layer is 1.2 nm to 1.8 nm.4. The magnetic tape ...

MAGNETIC TAPE

The magnetic tape includes a magnetic layer including ferromagnetic powder, non-magnetic powder, and a binding agent and a back coating layer including non-magnetic powder and a binding agent, in which the ferromagnetic powder is ferromagnetic hexagonal ferrite powder, a center line average surface roughness measured regarding a surface of the magnetic layer is equal to or smaller than 1.8 nm, an intensity ratio of a peak intensity of a diffraction peak of a (110) plane with respect to a peak intensity of a diffraction peak of a (114) plane of a hexagonal ferrite crystal structure obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, a vertical squareness ratio of the magnetic tape is 0.65 to 1.00, and a contact angle with respect to 1-bromonaphthalene measured regarding a surface of the back coating layer is 15.0° to 30.0°. 1. A magnetic tape comprising:a non-magnetic support;a magnetic layer including ferromagnetic powder, non-magnetic powder, and a binding agent on one surface side of the non-magnetic support; anda back coating layer including non-magnetic powder and a binding agent on the other surface side of the non-magnetic support,wherein the ferromagnetic powder is ferromagnetic hexagonal ferrite powder,a center line average surface roughness Ra measured regarding a surface of the magnetic layer is equal to or smaller than 1.8 nm,an intensity ratio Int(110)/Int(114) of a peak intensity Int(110) of a diffraction peak of a (110) plane with respect to a peak intensity Int(114) of a diffraction peak of a (114) plane of a hexagonal ferrite crystal structure obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0,a vertical squareness ratio of the magnetic tape is 0.65 to 1.00, anda 1-bromonaphthalene contact angle measured regarding a surface of the back coating layer is 15.0° to 30.0°.2. The magnetic tape according to claim 1 ,wherein the center line average ...

MAGNETIC RECORDING MEDIUM

The magnetic recording medium includes a magnetic layer containing ferromagnetic powder and a binder, in which the ferromagnetic powder is ferromagnetic hexagonal ferrite powder, the magnetic layer contains an abrasive, an intensity ratio of a peak intensity of a diffraction peak of (110) plane of a crystal structure of the hexagonal ferrite, determined by performing X-ray diffraction analysis on the magnetic layer by using an In-Plane method, to a peak intensity of a diffraction peak of (114) plane of the crystal structure is equal to or higher than 0.5 and equal to or lower than 4.0, a squareness ratio of the magnetic recording medium in a vertical direction is equal to or higher than 0.65 and equal to or lower than 1.00, and a coefficient of friction measured in a base material portion within a surface of the magnetic layer is equal to or lower than 0.30. 1. A magnetic recording medium comprising:a non-magnetic support; anda magnetic layer which is provided on the support and contains ferromagnetic powder and a binder,wherein the ferromagnetic powder is ferromagnetic hexagonal ferrite powder, the magnetic layer contains an abrasive, an intensity ratio (Int (110)/Int (114)) of a peak intensity Int (110) of a diffraction peak of (110) plane of a crystal structure of the hexagonal ferrite, determined by performing X-ray diffraction analysis on the magnetic layer by using an In-Plane method, to a peak intensity Int (114) of a diffraction peak of (114) plane of the crystal structure is equal to or higher than 0.5 and equal to or lower than 4.0,a squareness ratio of the magnetic recording medium in a vertical direction is equal to or higher than 0.65 and equal to or lower than 1.00, anda coefficient of friction measured in a base material portion within a surface of the magnetic layer is equal to or lower than 0.30.2. The magnetic recording medium according to claim 1 ,wherein the squareness ratio in a vertical direction is equal to or higher than 0.65 and equal to or ...

MAGNETIC RECORDING MEDIUM

The magnetic recording medium includes a magnetic layer which contains ferromagnetic hexagonal ferrite powder and a binder, in which the magnetic layer contains an abrasive and a fatty acid ester, Int (110)/Int (114) of a crystal structure of the hexagonal ferrite, determined by performing XRD analysis on the magnetic layer by using an In-Plane method, is equal to or higher than 0.5 and equal to or lower than 4.0, a squareness ratio of the magnetic recording medium in a vertical direction is equal to or higher than 0.65 and equal to or lower than 1.00, FWHMand FWHMis greater than 0 nm and equal to or smaller than 7.0 nm, and a difference between spacings measured within a surface of the magnetic layer by an optical interference method before and after the heating in a vacuum is greater than 0 nm and equal to or smaller than 8.0 nm. 1. A magnetic recording medium comprising:a non-magnetic support; anda magnetic layer which is provided on the support and contains ferromagnetic powder and a binder,wherein the ferromagnetic powder is ferromagnetic hexagonal ferrite powder, the magnetic layer contains an abrasive and a fatty acid ester, an intensity ratio (Int (110)/Int (114)) of a peak intensity Int (110) of a diffraction peak of (110) plane of a crystal structure of the hexagonal ferrite, determined by performing X-ray diffraction analysis on the magnetic layer by using an In-Plane method, to a peak intensity Int (114) of a diffraction peak of (114) plane of the crystal structure is equal to or higher than 0.5 and equal to or lower than 4.0,a squareness ratio of the magnetic recording medium in a vertical direction is equal to or higher than 0.65 and equal to or lower than 1.00,a full width at half maximum of a spacing distribution measured within a surface of the magnetic layer by an optical interference method before the magnetic recording medium is heated in a vacuum is greater than 0 nm and equal to or smaller than 7.0 nm,a full width at half maximum of a spacing ...

MAGNETIC TAPE

The magnetic tape includes a magnetic layer including ferromagnetic powder, non-magnetic powder, and a binding agent and a back coating layer including non-magnetic powder and a binding agent, in which the ferromagnetic powder is ferromagnetic hexagonal ferrite powder, an Ra measured regarding a surface of the magnetic layer is equal to or smaller than 1.8 nm, an intensity ratio of a peak intensity of a diffraction peak of a (110) plane with respect to a peak intensity of a diffraction peak of a (114) plane of a hexagonal ferrite crystal structure obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, a vertical squareness ratio of the magnetic tape is 0.65 to 1.00, and a logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding a surface of the hack coating layer is equal to or smaller than 0.060. 1. A magnetic tape comprising:a non-magnetic support;a magnetic layer including ferromagnetic powder, non-magnetic powder, and a binding agent on one surface side of the non-magnetic support; anda back coating layer including non-magnetic powder and a binding agent on the other surface sick of the non-magnetic support,wherein the ferromagnetic powder is ferromagnetic hexagonal ferrite powder,a center line average surface roughness Ra measured regarding a surface of the magnetic layer is equal to or smaller than 1.8 nm,an intensity ratio Int(110)/Int(114) of a peak intensity Int(110) of a diffraction peak of a (110) plane with respect to a peak intensity Int(114) of a diffraction peak of a (114) plane of a hexagonal ferrite crystal structure obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0,a vertical squareness ratio of the magnetic tape is 0.65 to 1.00, and.a logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding a surface of the back coating layer is equal to or smaller than 0.060.2. The magnetic tape ...

MAGNETIC TAPE, ITS CLEANING METHOD, AND OPTICAL SERVOTRACK FORMING/CLEANING APPARATUS

A magnetic tape which comprises a nonmagnetic support, a magnetic layer which is formed on one surface of the nonmagnetic support, and a backcoat layer which comprises a binder and nonmagnetic powder containing carbon black as a component and which is formed on the other surface of the nonmagnetic support, having pits for optical servo formed thereon, characterized in that the average of the reflectance on the flat portion of the backcoat layer is 8.5% or higher, and that the maximum rate of fluctuation of the reflectance on the flat portion, depending on a position of the magnetic tape: 1. A magnetic tape comprising a nonmagnetic support , a magnetic layer which is formed on one surface of the nonmagnetic support , and a backcoat layer which comprises a binder and nonmagnetic powder containing carbon black as a component , which is formed on the other surface of the nonmagnetic support , and which has pits for optical servo formed thereon , whereina content of the nonmagnetic powder in the backcoat layer is from 50 wt. % to 60 wt. % based on the total weight of the nonmagnetic powder and the binder in the backcoat layer;an average surface roughness Ra of a flat portion of the backcoat layer, which is measured with an atomic force microscope, is 30 nm or less; andan average of reflection on a flat portion of the backcoat layer is from 8.5% to 14.9%.2. The magnetic tape according to claim 1 , wherein a maximum rate of fluctuation of the reflectance on the flat portion of the backcoat layer depending on a position of the magnetic tape claim 1 , which is defined by the following equation claim 1 , is from 2.8% to 10%:{'br': None, '[Maximum of absolute value of (Reflectance−Average of reflectance)]×100/(Average of reflectance).'}3. The magnetic tape according to claim 1 , wherein a half width of fluctuation of the surface roughness Ra claim 1 , depending on a site of the magnetic tape claim 1 , is 5 nm or less. This application is a Divisional of co-pending application ...

MAGNETIC TAPE, MAGNETIC TAPE CARTRIDGE, AND MAGNETIC RECORDING AND REPRODUCING APPARATUS

The magnetic tape includes: a non-magnetic support; and a magnetic layer including ferromagnetic powder, in which a change amount of a loss tangent tan δ at a measurement temperature in a range of 50° C. to 100° C. before and after heating at 70° C. for 10 hours is 0.000 or more and 0.012 or less. 1. A magnetic tape comprising:a non-magnetic support; anda magnetic layer including ferromagnetic powder,wherein a change amount Δ1 of a loss tangent tan δ at a measurement temperature in a range of 50° C. to 100° C. before and after heating at 70° C. for 10 hours is 0.000 or more and 0.012 or less.2. The magnetic tape according to claim 1 ,wherein the magnetic tape has the magnetic layer on one surface side of the non-magnetic support and has a back coating layer including non-magnetic powder on the other surface side, and {'br': None, 'i': =Δa×[Da/', 'Da+Db', +Δb×[Db/', 'Da+Db, 'Δ2()()]'}, 'a change amount Δ2 obtained by the following formula is 0.000 or more and 0.020 or less,'}in the formula, Da is a thickness of a portion on the magnetic layer side on the non-magnetic support, Δa is a change amount of a loss tangent tan δ of the portion on the magnetic layer side at a measurement temperature in a range of 50° C. to 100° C. before and after the heating, Db is a thickness of a portion on the back coating layer side on the non-magnetic support, and Δb is a change amount of a loss tangent tan δ of the portion on the back coating layer side at a measurement temperature in a range of 50° C. to 100° C. before and after the heating.3. The magnetic tape according to claim 2 ,wherein the thickness Da of the portion on the magnetic layer side is 0.20 μm or more and 0.50 μm or less, andthe thickness Db of the portion on the back coating layer side is 0.20 μm or more and 1.50 μm or less.4. The magnetic tape according to claim 2 ,wherein the thickness Da of the portion on the magnetic layer side is 0.20 μm or more and 1.00 μm or less, andthe thickness Db of the portion on the back ...

MAGNETIC TAPE

The magnetic tape comprises, on one surface of a nonmagnetic support, a nonmagnetic layer comprising nonmagnetic powder, lubricant, and binder, comprises, on a surface of the nonmagnetic layer, a magnetic layer comprising magnetic powder, lubricant, and binder, and comprises, on the opposite surface of the nonmagnetic support from the surface on which the nonmagnetic layer and magnetic layer are present, a backcoat layer comprising nonmagnetic powder, lubricant, and binder, wherein the contact angle for water of a surface of the magnetic layer ranges from 95° to 100°, and the contact angle for water of a surface of the backcoat layer ranges from 95° to 100°. 1. A magnetic tape , comprising , on one surface of a nonmagnetic support , a nonmagnetic layer comprising nonmagnetic powder , lubricant , and binder;comprising, on a surface of the nonmagnetic layer, a magnetic layer comprising magnetic powder, lubricant, and binder; andcomprising, on an opposite surface of the nonmagnetic support from the surface on which the nonmagnetic layer and magnetic layer are present, a backcoat layer comprising nonmagnetic powder, lubricant, and binder, whereina contact angle for water of a surface of the magnetic layer ranges from 95° to 100°, anda contact angle for water of a surface of the backcoat layer ranges from 95° to 100°.2. The magnetic tape according to claim 1 , wherein a thickness of the nonmagnetic layer ranges from 0.05 to 0.50 μm.3. The magnetic tape according to claim 1 , wherein the magnetic layer comprises:{'b': '1', 'nonmagnetic filler having an average particle size φ1; and'}{'b': 2', '1, 'nonmagnetic filler having an average particle size φ2 smaller than φ1 and a Mohs hardness greater than a Mohs hardness of nonmagnetic filler ;'} {'br': None, '20 nm≦φ1−φ2<50 nm equation 1.'}, 'where φ1 and φ2, each unit of which is nm, satisfy equation 14. The magnetic tape according to claim 2 , wherein the magnetic layer comprises:{'b': '1', 'nonmagnetic filler having an ...

MAGNETIC RECORDING MEDIUM AND MAGNETIC RECORDING AND REPRODUCING DEVICE

The magnetic recording medium includes a non-magnetic support; and a magnetic layer including a ferromagnetic powder, in which an isoelectric point of a surface zeta potential of the magnetic layer after pressing the magnetic layer at a pressure of 70 atm is equal to or less than 3.8. 1. A magnetic recording medium comprising:a non-magnetic support; anda magnetic layer including a ferromagnetic powder,wherein an isoelectric point of a surface zeta potential of the magnetic layer after pressing the magnetic layer at a pressure of 70 atm is equal to or less than 3.8.2. The magnetic recording medium according to claim 1 ,wherein the isoelectric point is 2.5 to 3.8.3. The magnetic recording medium according to claim 1 ,wherein the magnetic layer includes inorganic oxide-based particles.4. The magnetic recording medium according to claim 3 ,wherein the inorganic oxide-based particles are composite particles of an inorganic oxide and a polymer.5. The magnetic recording medium according to claim 1 ,wherein the magnetic layer includes a binding agent having an acidic group.6. The magnetic recording medium according to claim 5 ,wherein the acidic group is at least one kind of acidic group selected from the group consisting of sulfonic acid groups and salts thereof.7. The magnetic recording medium according to claim 1 , further comprising:a non-magnetic layer including a non-magnetic powder between the non-magnetic support and the magnetic layer.8. The magnetic recording medium according to claim 1 , further comprising:a back coating layer including a non-magnetic powder on a surface of the non-magnetic support opposite to a surface provided with the magnetic layer.9. The magnetic recording medium according to claim 1 ,wherein the magnetic recording medium is a magnetic tape.10. A magnetic recording and reproducing device comprising:a magnetic recording medium; anda magnetic head,whereinthe magnetic recording medium is a magnetic recording medium comprising:a non-magnetic ...

MAGNETIC TAPE HAVING CHARACTERIZED PSD RATIO, MAGNETIC TAPE CARTRIDGE, AND MAGNETIC RECORDING AND REPRODUCING APPARATUS

The magnetic tape includes a non-magnetic support, a magnetic layer that includes ferromagnetic powder having an average particle volume of 2,500 nmor less on one surface side of the non-magnetic support, and a back coating layer that includes non-magnetic powder on the other surface side of the non-magnetic support, in which the ferromagnetic powder is ferromagnetic powder selected from the group consisting of hexagonal ferrite powder and ε-iron oxide powder, and a ratio (PSD/PSD) of the magnetic layer and the back coating layer is in a range of 0.0050 to 0.20. A magnetic tape cartridge and a magnetic recording and reproducing apparatus include the magnetic tape. 1. A magnetic tape comprising:a non-magnetic support;a magnetic layer that includes ferromagnetic powder above one surface side of the non-magnetic support;a non-magnetic layer that includes non-magnetic powder between the magnetic layer and the non-magnetic support; anda back coating layer that includes non-magnetic powder on the other surface side of the non-magnetic support,wherein the ferromagnetic powder is ferromagnetic powder selected from the group consisting of hexagonal ferrite powder and ε-iron oxide powder,a thickness of the non-magnetic layer is 0.1 to 1.0 μm,{'sub': 5μm-PSDmag', '10μm-PSDbc', '5μm-PSDmag', '10μm-PSDbc, 'a ratio PSD/PSDof a PSDat a 5 μm pitch on a surface of the magnetic layer and a PSDat a 10 μm pitch on a surface of the back coating layer is in a range of 0.0052 to 0.20, and'}the PSD or power spectrum density at a given pitch in microns is obtained by:measuring profile data of a measurement target surface using a non-contact optical interference type surface roughness machine, the target surface being either the magnetic layer or the back coating layer;calculating a PSD in a longitudinal direction of the magnetic tape;employing a mounting function of the machine to carry out a Fourier transformation of the profile data in the longitudinal direction, and calculate a PSD; ...

MAGNETIC TAPE AND MAGNETIC RECORDING AND REPRODUCING DEVICE

Provided are a magnetic tape, in which a magnetic layer includes a ferromagnetic powder, a binding agent, and an oxide abrasive, ΔSFD in a longitudinal direction of the magnetic tape calculated by Expression 1, ΔSFD=SFD−SFD, is equal to or smaller than 0.50, a logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding a surface of the magnetic layer is equal to or smaller than 0.050, and an average particle diameter of the oxide abrasive obtained from a secondary ion image obtained by irradiating the surface of the magnetic layer with a focused ion beam is 0.04 μm to 0.08 μm, and a magnetic recording and reproducing device including this magnetic tape. 1. A magnetic tape comprising:a non-magnetic support; anda magnetic layer including a ferromagnetic powder and a binding agent on the non-magnetic support, {'br': None, 'sub': 25° C.', '−190° C., 'ΔSFD=SFD−SFD\u2003\u2003Expression 1,'}, 'wherein ΔSFD in a longitudinal direction of the magnetic tape calculated by Expression 1 is equal to or smaller than 0.50,'}{'sub': 25° C.', '−190° C., 'in Expression 1, the SFDis a switching field distribution SFD measured in the longitudinal direction of the magnetic tape at a temperature of 25° C., and the SFDis a switching field distribution SFD measured in the longitudinal direction of the magnetic tape at a temperature of −190° C.,'}the magnetic layer includes an oxide abrasive,a logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding a surface of the magnetic layer is equal to or smaller than 0.050, andan average particle diameter of the oxide abrasive obtained from a secondary ion image obtained by irradiating the surface of the magnetic layer with a focused ion beam is 0.04 μm to 0.08 μm.2. The magnetic tape according to claim 1 ,wherein the logarithmic decrement is 0.010 to 0.050.3. The magnetic tape according to claim 1 ,wherein the ΔSFD is 0.03 to 0.50.4. The magnetic tape according to claim 1 ,wherein the ...

MAGNETIC RECORDING MEDIUM AND MAGNETIC RECORDING AND REPRODUCING DEVICE

Provided are a magnetic recording medium, in which a magnetic layer includes ferromagnetic hexagonal ferrite powder, a binding agent, and an oxide abrasive, an intensity ratio Int(110)/Int(114) obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, a vertical squareness ratio of the magnetic recording medium is 0.65 to 1.00, a logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding a surface of the magnetic layer is equal to or smaller than 0.050, and an average particle diameter of the oxide abrasive obtained from a secondary ion image obtained by irradiating the surface of the magnetic layer with a focused ion beam is 0.04 μm to 0.08 μm, and a magnetic recording and reproducing device including this magnetic recording medium. 1. A magnetic recording medium comprising:a non-magnetic support; anda magnetic layer including a ferromagnetic powder and a binding agent,wherein the ferromagnetic powder is a ferromagnetic hexagonal ferrite powder,the magnetic layer includes an oxide abrasive,an intensity ratio Int(110)/Int(114) of a peak intensity Int(110) of a diffraction peak of a (110) plane with respect to a peak intensity Int(114) of a diffraction peak of a (114) plane of a hexagonal ferrite crystal structure obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0,a vertical squareness ratio of the magnetic recording medium is 0.65 to 1.00,a logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding a surface of the magnetic layer is equal to or smaller than 0.050, andan average particle diameter of the oxide abrasive obtained from a secondary ion image obtained by irradiating the surface of the magnetic layer with a focused ion beam is 0.04 μm to 0.08 μm.2. The magnetic recording medium according to claim 1 ,wherein the vertical squareness ratio is 0.65 to 0.90.3. The magnetic recording medium according to ...

MAGNETIC TAPE, MAGNETIC TAPE CARTRIDGE, AND MAGNETIC TAPE APPARATUS

The magnetic tape includes a non-magnetic support, and a magnetic layer including a ferromagnetic powder. A rate of change (AlFeSil abrasion value 2/AlFeSil abrasion value 1) in AlFeSil abrasion value measured on a surface of the magnetic layer before and after storage of the magnetic tape in an environment of a temperature of 23° C. and a relative humidity of 50% is 0.7 or more. 1. A magnetic tape comprising:a non-magnetic support; anda magnetic layer including a ferromagnetic powder,wherein a rate of change in AlFeSil abrasion value measured on a surface of the magnetic layer before and after storage of the magnetic tape in an environment of a temperature of 23° C. and a relative humidity of 50%, an AlFeSil abrasion value 2/an AlFeSil abrasion value 1, is 0.7 or more,the AlFeSil abrasion value 1 is an AlFeSil abrasion value measured by applying a tension of 2.0 N in a longitudinal direction of the magnetic tape, andthe AlFeSil abrasion value 2 is an AlFeSil abrasion value measured by applying a tension of 2.0 N in the longitudinal direction of the magnetic tape for which the AlFeSil abrasion value 1 has been measured after the magnetic tape is stored for 24 hours after being reciprocatively slid 1500 times with respect to an LTO8 head.2. The magnetic tape according to claim 1 ,wherein the AlFeSil abrasion value 2/the AlFeSil abrasion value 1 is 0.7 or more and 1.0 or less.3. The magnetic tape according to claim 1 ,wherein the magnetic layer further includes one or more non-magnetic powders.4. The magnetic tape according to claim 3 ,wherein the non-magnetic powder includes an alumina powder.5. The magnetic tape according to claim 1 , further comprising:a non-magnetic layer including a non-magnetic powder between the non-magnetic support and the magnetic layer.6. The magnetic tape according to claim 1 , further comprising:a back coating layer including a non-magnetic powder on a surface side of the non-magnetic support opposite to a surface side having the magnetic ...

MAGNETIC RECORDING MEDIUM

A magnetic recording medium includes: a substrate that is long in shape; and a magnetic layer containing magnetic powder and a binder. The glass transition point of the binder is not lower than 75° C. In a case where atomic force microscope observation images in a 10 μm×10 μm rectangular shape are acquired at five locations randomly selected from the surface on the side of the magnetic layer, any linear protrusion that is 3 nm to 20 nm in height, is 0.3 μm to 1.0 μm in width, and extends across two sides of the observation image does not exist in the observation images of four locations among the acquired observation images of the five locations. 1. A magnetic recording medium comprising:a substrate that is long in shape; anda magnetic layer containing magnetic powder and a binder, whereina glass transition point of the binder is not lower than 75° C., andin a case where atomic force microscope observation images in a 10 μm×10 μm square shape are acquired at five locations randomly selected from a surface on a side of the magnetic layer, any linear protrusion that is 3 nm to 20 nm in height, is 0.3 μm to 1.0 μm in width, and extends across two sides of the observation image does not exist in the observation images of four locations among the acquired observation images of the five locations.2. The magnetic recording medium according to claim 1 , wherein an arithmetic average roughness Ra of the surface is not higher than 1.5 nm.3. The magnetic recording medium according to claim 1 , wherein an average thickness is not greater than 5.0 μm.4. The magnetic recording medium according to claim 1 , wherein an average thickness is not greater than 4.5 μm.5. The magnetic recording medium according to claim 1 , further comprisinga nonmagnetic layer disposed between the substrate and the magnetic layer.6. The magnetic recording medium according to claim 5 , wherein a sum of an average thickness of the magnetic layer and an average thickness of the nonmagnetic layer is not ...

GLASS SUBSTRATE FOR MAGNETIC DISK AND MANUFACTURING METHOD THEREOF

The present invention provides a method for efficiently manufacturing a glass substrate for magnetic disk having good accuracy of a surface irregularity and an impact resistance. The method includes the steps of: performing press forming to molten glass to prepare a sheet glass material, the sheet glass material having a roughness of the principal surface of 0.01 μm or less and target flatness of a glass substrate for magnetic disk; chemically strengthening the sheet glass material by dipping the sheet glass material in a chemically strengthening salt, thereby preparing a disk substrate; polishing the principal surfaces of the disk substrate. A thickness of the sheet glass material prepared in the press forming step is larger than a target thickness of the glass substrate for magnetic disk by a polishing quantity of the principal surface polishing step. 1. A manufacturing method of a glass substrate for a magnetic disk , comprising:forming a sheet glass material by press forming a lump of molten glass while sandwiching the lump from opposing sides using surfaces of a pair of dies set at approximately the same temperature, such that the surfaces of the pair of dies are brought into close contact at approximately identical timing; andpolishing a principal surface of the sheet glass material by pressing a polishing pad against the principal surface of the sheet glass material while supplying a polishing solution including a polishing material between the sheet glass material and the polishing pad, and relatively moving the sheet glass material and the polishing pad.2. A manufacturing method of a glass substrate for a magnetic disk according to claim 1 , wherein the forming of the sheet glass material includes:press forming while sandwiching the lump between the surfaces of the pair of dies; andopening the pair of dies immediately thereafter.3. A manufacturing method of a glass substrate for a magnetic disk according to claim 1 , wherein the principal surface of the ...

MAGNETIC RECORDING MEDIUM, LAMINATE, AND FLEXIBLE DEVICE

A magnetic recording medium according to a first technique includes an elongated substrate having a first surface and a second surface, a first reinforcing layer disposed on the first surface, a second reinforcing layer disposed on the second surface, an adhesion suppressing layer disposed on the second reinforcing layer, and a recording layer disposed on the first reinforcing layer or the adhesion suppressing layer. 1. A magnetic recording medium comprising:an elongated substrate having a first surface and a second surface;a first reinforcing layer disposed on the first surface;a second reinforcing layer disposed on the second surface;an adhesion suppressing layer disposed on the second reinforcing layer; anda recording layer disposed on the first reinforcing layer or the adhesion suppressing layer.2. The magnetic recording medium according to claim 1 , whereinthe second reinforcing layer has an average thickness of 75 nm or more and 300 nm or less, anda ratio of an average thickness of the adhesion suppressing layer to the second reinforcing layer is 0.005 or more and 0.35 or less.3. The magnetic recording medium according to claim 1 , wherein the first reinforcing layer and the second reinforcing layer each contain at least one of a metal and a metal compound.4. The magnetic recording medium according to claim 3 , wherein the metal contains at least one of aluminum claim 3 , copper claim 3 , and cobalt.5. The magnetic recording medium according to claim 1 , wherein the adhesion suppressing layer contains carbon.6. The magnetic recording medium according to claim 5 , wherein the carbon is diamond-like carbon.7. The magnetic recording medium according to claim 1 , wherein the adhesion suppressing layer contains a metal oxide.8. The magnetic recording medium according to claim 7 , wherein the metal oxide includes at least one of aluminum oxide claim 7 , copper oxide claim 7 , and cobalt oxide.9. The magnetic recording medium according to claim 1 , whereinthe ...

MAGNETIC TAPE, MAGNETIC TAPE CARTRIDGE, AND MAGNETIC TAPE APPARATUS

A magnetic tape in which a minimum value of TDStens among five TDStens measured respectively at a temperature of 16° C. and a relative humidity of 20%, a temperature of 16° C. and a relative humidity of 80%, a temperature of 26° C. and a relative humidity of 80%, a temperature of 32° C. and a relative humidity of 20% and a temperature of 32° C. and a relative humidity of 55% is 1.43 μm/N or more, a ratio of a change of TDStens to a change of a relative humidity obtained from the five TDStens is 0.005 μm/N/% or less, and a ratio of a change of TDStens to a change of a temperature obtained from the five TDStens is 0.020 μm/N/° C. or less. 1. A magnetic tape comprising:a non-magnetic support and a magnetic layer containing a ferromagnetic powder, whereinthe magnetic layer has a plurality of servo bands, and a region sandwiched between two adjacent servo bands is called a data band, a temperature of 16° C. and a relative humidity of 20%,', 'a temperature of 16° C. and a relative humidity of 80%,', 'a temperature of 26° C. and a relative humidity of 80%,', 'a temperature of 32° C. and a relative humidity of 20%, and', 'a temperature of 32° C. and a relative humidity of 55%,, 'among five TDStens measured respectively in the following five environments;'}a minimum value of the TDStens is 1.43 μm/N or more,where TDStens is a ratio of a change of a servo band interval to a change of a tension obtained from a plurality of servo band intervals measured by respectively applying a plurality of different tensions in a longitudinal direction of a magnetic tape as a value based on a magnetic tape with a ½ inch width and four total data bands,a ratio of a change of the TDStens to a change of the relative humidity, which is obtained from the five TDStens, is 0.005 μm/N/% or less, anda ratio of a change of the TDStens to a change of the temperature, which is obtained from the five TDStens, is 0.020 μm/N/° C. or less.2. The magnetic tape according to claim 1 ,wherein the magnetic tape ...

MAGNETIC RECORDING MEDIUM, MAGNETIC RECORDING AND REPRODUCING APPARATUS, MAGNETIC TAPE CARTRIDGE, AND MAGNETIC TAPE CARTRIDGE GROUP

In the magnetic recording medium, a number distribution A of a plurality of bright regions, based on equivalent circle diameters thereof, in a binarized image of a secondary electron image obtained by imaging a surface of the magnetic layer by a scanning electron microscope at an acceleration voltage of 5 kV and a number distribution B of a plurality of dark regions, based on equivalent circle diameters thereof, in a binarized image of a secondary electron image obtained by imaging a surface of the magnetic layer by a scanning electron microscope at an acceleration voltage of 2 kV respectively satisfy a predetermined number distribution. 1. A magnetic recording medium comprising:a non-magnetic support; anda magnetic layer including ferromagnetic powder, (1) bright regions having an equivalent circle diameter of 1 nm or more and 50 nm or less are 20,000 or more and 40,000 or less;', '(2) bright regions having an equivalent circle diameter of 51 nm or more and 100 nm or less are 7,000 or more and 25,000 or less; and', '(3) bright regions having an equivalent circle diameter of 101 nm or more are 100 or more and 1,000 or less, and, 'wherein a number distribution A of a plurality of bright regions, based on equivalent circle diameters thereof, in a binarized image of a secondary electron image obtained by imaging a surface of the magnetic layer by a scanning electron microscope at an acceleration voltage of 5 kV satisfies the following (1) to (3) (4) dark regions having an equivalent circle diameter of 1 nm or more and 50 nm or less are 100 or more and 5,000 or less;', '(5) dark regions having an equivalent circle diameter of 51 nm or more and 100 nm or less are 200 or more and 5,000 or less; and', '(6) dark regions having an equivalent circle diameter of 101 nm or more are 300 or more and 600 or less., 'a number distribution B of a plurality of dark regions, based on equivalent circle diameters thereof, in a binarized image of a secondary electron image obtained by ...

MAGNETIC RECORDING AND REPRODUCING DEVICE

In the magnetic recording and reproducing device, a distal end width of the first magnetic pole in the recording element is substantially the same as a distal end width of the second magnetic pole; the reproducing element width of the reproducing element is equal to or less than 0.8 μm; and in the magnetic recording medium, a number distribution A of equivalent circle diameters of a plurality of bright areas in a binarized image of a secondary electron image obtained by imaging a surface of the magnetic layer with a scanning electron microscope at an acceleration voltage of 5 kV, and a number distribution B of equivalent circle diameters of a plurality of dark areas in a binarized image of a secondary electron image obtained by imaging the surface of the magnetic layer with a scanning electron microscope at an acceleration voltage of 2 kV satisfy predetermined number distribution, respectively. w 2. The magnetic recording and reproducing device according to claim 1 ,wherein a total thickness of the magnetic recording medium is equal to or less than 5.3 μm.3. The magnetic recording and reproducing device according to claim 1 ,wherein the magnetic recording medium includes a non-magnetic layer including a non-magnetic powder between the non-magnetic support and the magnetic layer.4. The magnetic recording and reproducing device according to claim 1 , wherein the magnetic recording medium includes a back coating layer including anon-magnetic powder on a surface of the non-magnetic support opposite to a surface provided with the magnetic layer.5. The magnetic recording and reproducing device according to claim 1 ,wherein the magnetic layer includes two or more kinds of non-magnetic powder.6. The magnetic recording and reproducing device according to claim 5 ,wherein the non-magnetic powder of the magnetic layer includes an alumina powder.7. The magnetic recording and reproducing device according to claim 5 ,wherein the non-magnetic powder of the magnetic layer includes ...

MAGNETIC RECORDING MEDIUM, MAGNETIC RECORDING AND REPRODUCING APPARATUS, MAGNETIC TAPE CARTRIDGE, AND MAGNETIC TAPE CARTRIDGE GROUP

In the magnetic recording medium, a number distribution A of a plurality of bright regions, based on equivalent circle diameters thereof, in a binarized image of a secondary electron image obtained by imaging a surface of the magnetic layer by a scanning electron microscope at an acceleration voltage of 5 kV and a number distribution B of a plurality of dark regions, based on equivalent circle diameters thereof, in a binarized image of a secondary electron image obtained by imaging a surface of the magnetic layer by a scanning electron microscope at an acceleration voltage of 2 kV respectively satisfy a predetermined number distribution. 1. A magnetic recording medium comprising:a non-magnetic support; anda magnetic layer including ferromagnetic powder, (1) bright regions having an equivalent circle diameter of 1 nm or more and 50 nm or less are 25,000 or more and 40,000 or less;', '(2) bright regions having an equivalent circle diameter of 51 nm or more and 100 nm or less are 7,000 or more and 25,000 or less; and', '(3) bright regions having an equivalent circle diameter of 101 nm or more are 100 or more and 1,000 or less, and, 'wherein a number distribution A of a plurality of bright regions, based on equivalent circle diameters thereof, in a binarized image of a secondary electron image obtained by imaging a surface of the magnetic layer by a scanning electron microscope at an acceleration voltage of 5 kV satisfies the following (1) to (3) (4) dark regions having an equivalent circle diameter of 1 nm or more and 50 nm or less are 1,000 or more and 25,000 or less;', '(5) dark regions having an equivalent circle diameter of 51 nm or more and 100 nm or less are 200 or more and 5,000 or less; and', '(6) dark regions having an equivalent circle diameter of 101 nm or more are 200 or more and 350 or less., 'a number distribution B of a plurality of dark regions, based on equivalent circle diameters thereof, in a binarized image of a secondary electron image obtained by ...

MAGNETIC RECORDING MEDIUM, MAGNETIC RECORDING AND REPRODUCING APPARATUS, MAGNETIC TAPE CARTRIDGE, AND MAGNETIC TAPE CARTRIDGE GROUP

In the magnetic recording medium, a number distribution A of a plurality of bright regions, based on equivalent circle diameters thereof, in a binarized image of a secondary electron image obtained by imaging a surface of the magnetic layer by a scanning electron microscope at an acceleration voltage of 5 kV and a number distribution B of a plurality of dark regions, based on equivalent circle diameters thereof, in a binarized image of a secondary electron image obtained by imaging a surface of the magnetic layer by a scanning electron microscope at an acceleration voltage of 2 kV respectively satisfy a predetermined number distribution. 1. A magnetic recording medium comprising:a non-magnetic support; anda magnetic layer including ferromagnetic powder, (1) bright regions having an equivalent circle diameter of 1 nm or more and 50 nm or less are 10,000 or more and 30,000 or less;', '(2) bright regions having an equivalent circle diameter of 51 nm or more and 100 nm or less are 7,000 or more and 25,000 or less; and', '(3) bright regions having an equivalent circle diameter of 101 nm or more are 3,000 or more and 7,000 or less, and, 'wherein a number distribution A of a plurality of bright regions, based on equivalent circle diameters thereof, in a binarized image of a secondary electron image obtained by imaging a surface of the magnetic layer by a scanning electron microscope at an acceleration voltage of 5 kV satisfies the following (1) to (3) (4) dark regions having an equivalent circle diameter of 1 nm or more and 50 nm or less are 1,000 or more and 25,000 or less;', '(5) dark regions having an equivalent circle diameter of 51 nm or more and 100 nm or less are 200 or more and 5,000 or less; and', '(6) dark regions having an equivalent circle diameter of 101 nm or more are 200 or more and 350 or less., 'a number distribution B of a plurality of dark regions, based on equivalent circle diameters thereof, in a binarized image of a secondary electron image obtained ...

Magnetic tape cartridge and magnetic tape apparatus

The magnetic tape cartridge includes a magnetic tape that is accommodated in the magnetic tape cartridge while being wound around a reel hub. The magnetic tape has a non-magnetic support and a magnetic layer including ferromagnetic powder, and includes one or more components selected from the group consisting of a fatty acid and a fatty acid amide in a portion on the magnetic layer side on the non-magnetic support, and after the magnetic tape cartridge is stored in an environment of an atmosphere temperature of 60° C. and a relative humidity of 80% for 24 hours, a C—H derived C concentration calculated from a C—H peak area ratio of C1s spectra obtained by X-ray photoelectron spectroscopic analysis performed at a photoelectron take-off angle of 10 degrees on a surface of the magnetic layer in an inner region during winding of the magnetic tape is 45 at % or more.

MAGNETIC TAPE, MAGNETIC TAPE CARTRIDGE, AND MAGNETIC TAPE APPARATUS

The magnetic tape in which a difference (S−S) between a spacing Sand a spacing Sobtained after n-hexane cleaning on a surface of the magnetic layer is equal to or less than 32 nm. The Sis a value obtained as a spacing under a pressing force of 0.1 atm from a relational expression between a pressure and a spacing obtained by performing a spacing measurement on the surface of the magnetic layer by an optical interference method under a pressing force of each of a plurality of different pressures after the n-hexane cleaning, and Sis a spacing measured on the surface of the magnetic layer by the optical interference method under the pressing force of 1.6 atm after the n-hexane cleaning. 1. A magnetic tape comprising:a non-magnetic support; anda magnetic layer containing a ferromagnetic powder,{'sub': 0.1', '1.6', '0.1', '1.6, 'wherein a difference, S−S, between a spacing Sand a spacing Seach obtained after n-hexane cleaning on a surface of the magnetic layer is equal to or less than 32 nm,'}{'sub': '0.1', 'the spacing Sis a value obtained as a spacing under a pressing force of 0.1 atm from a relational expression between a pressure and a spacing obtained by performing a spacing measurement on the surface of the magnetic layer by an optical interference method under a pressing force of each of a plurality of different pressures after n-hexane cleaning, and'}{'sub': '1.6', 'the spacing Sis a spacing measured on the surface of the magnetic layer by the optical interference method under a pressing force of 1.6 atm after n-hexane cleaning.'}2. The magnetic tape according to claim 1 ,wherein the difference is equal to or less than 30 nm.3. The magnetic tape according to claim 1 ,wherein the difference is equal to or more than 10 nm and equal to or less than 30 nm.4. The magnetic tape according to claim 1 ,wherein the magnetic layer contains inorganic oxide particles.5. The magnetic tape according to claim 4 ,wherein the inorganic oxide particles are composite particles of an ...

Magnetic tape, magnetic tape cartridge, and magnetic tape apparatus

Provided are a magnetic tape including: a non-magnetic support; and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, in which a total thickness of the magnetic tape is equal to or smaller than 5.30 μm, the magnetic layer has a servo pattern, a center line average surface roughness Ra measured on a surface of the magnetic layer is equal to or smaller than 1.8 nm, and an absolute value ΔN of a difference between a refractive index Nxy of the magnetic layer, measured in an in-plane direction and a refractive index Nz of the magnetic layer, measured in a thickness direction is 0.25 to 0.40, a magnetic tape cartridge and a magnetic tape apparatus including this magnetic tape, a magnetic tape cartridge and a magnetic tape apparatus including this magnetic tape.

MAGNETIC TAPE, MAGNETIC TAPE CARTRIDGE, AND MAGNETIC TAPE APPARATUS

Provided are a magnetic tape including: a non-magnetic support; a magnetic layer including ferromagnetic powder and a binding agent on one surface side of the non-magnetic support; and a back coating layer including non-magnetic powder and a binding agent on the other surface side of the non-magnetic support, in which an isoelectric point of a surface zeta potential of the magnetic layer is equal to or greater than 5.5, and an isoelectric point of a surface zeta potential of the back coating layer is equal to or greater than 4.5, a magnetic tape cartridge, and a magnetic tape apparatus including this magnetic tape. 1. A magnetic tape comprising:a non-magnetic support;a magnetic layer including ferromagnetic powder and a binding agent on one surface side of the non-magnetic support; anda back coating layer including non-magnetic powder and a binding agent on the other surface side of the non-magnetic support,wherein an isoelectric point of a surface zeta potential of the magnetic layer is equal to or greater than 5.5, andan isoelectric point of a surface zeta potential of the back coating layer is equal to or greater than 4.5.2. The magnetic tape according to claim 1 ,wherein the isoelectric point of the surface zeta potential of the magnetic layer is 5.5 to 7.0.3. The magnetic tape according to claim 1 ,wherein the isoelectric point of the surface zeta potential of the back coating layer is 4.5 to 6.0.4. The magnetic tape according to claim 1 ,wherein the binding agent of the magnetic layer is a binding agent including an acidic group.5. The magnetic tape according to claim 4 ,wherein the acidic group includes at least one kind of acidic group selected from the group consisting of a sulfonic acid group and a salt thereof.6. The magnetic tape according to claim 1 ,wherein the binding agent of the back coating layer is a binding agent including an acidic group.7. The magnetic tape according to claim 6 ,wherein the acidic group includes at least one kind of acidic ...

HEXAGONAL STRONTIUM FERRITE POWDER, MAGNETIC RECORDING MEDIUM, AND MAGNETIC RECORDING AND REPRODUCING APPARATUS

A hexagonal strontium ferrite powder, in which an average particle size is 10.0 to 25.0 nm, a content of one or more kinds of atom selected from the group consisting of a gallium atom, a scandium atom, an indium atom, and an antimony atom is 1.0 to 15.0 atom % with respect to 100.0 atom % of an iron atom, and a coercivity Hc is greater than 2,000 Oe and smaller than 4,000 Oe. A magnetic recording medium including: a non-magnetic support; and a magnetic layer including a ferromagnetic powder and a binding agent on the non-magnetic support, in which the ferromagnetic powder is the hexagonal strontium ferrite powder. A magnetic recording and reproducing apparatus including this magnetic recording medium. 1. A hexagonal strontium ferrite powder ,wherein an average particle size is 10.0 to 25.0 nm,a content of one or more kinds of atom selected from the group consisting of a gallium atom, a scandium atom, an indium atom, and an antimony atom is 1.0 to 15.0 atom % with respect to 100.0 atom % of an iron atom, anda coercivity Hc is greater than 2,000 Oe and smaller than 4,000 Oe.2. The hexagonal strontium ferrite powder according to claim 1 , which is a ferromagnetic powder for magnetic recording.3. The hexagonal strontium ferrite powder according to claim 1 ,{'sup': '2', 'wherein a mass magnetization as is equal to or greater than 41 A·m/kg.'}4. The hexagonal strontium ferrite powder according to claim 1 ,wherein the content of the one or more kinds of atom selected from the group consisting of a gallium atom, a scandium atom, an indium atom, and an antimony atom is 1.0 to 12.0 atom % with respect to 100.0 atom % of an iron atom.5. The hexagonal strontium ferrite powder according to claim 1 , comprising:a gallium atom.6. The hexagonal strontium ferrite powder according to claim 4 , comprising:a gallium atom.7. The hexagonal strontium ferrite powder according to claim 1 , comprising:a scandium atom.8. The hexagonal strontium ferrite powder according to claim 4 , comprising ...

MAGNETIC TAPE

The magnetic tape has a magnetic layer containing ferromagnetic powder, abrasive, and binder on a nonmagnetic support, wherein the centerline average surface roughness Ra measured on the surface of the magnetic layer is less than or equal to 1.8 nm, the contact angle for 1-bromonaphthalene that is measured on the surface of the magnetic layer falls within a range of 45.0° to 60.0°, and the coefficient of friction that is measured on the base portion of the surface of the magnetic layer is less than or equal to 0.35. 1. A magnetic tape ,which comprises a magnetic layer comprising ferromagnetic powder, abrasive, and binder on a nonmagnetic support, wherein:a centerline average surface roughness Ra measured on a surface of the magnetic layer is less than or equal to 1.8 nm;a contact angle for 1-bromonaphthalene that is measured on the surface of the magnetic layer falls within a range of 45.0° to 60.0°; anda coefficient of friction that is measured on a base portion of the surface of the magnetic layer is less than or equal to 0.35.2. The magnetic tape according to claim 1 ,wherein the centerline average surface roughness Ra falls within a range of 1.2 nm to 1.8 nm.3. The magnetic tape according to claim 1 ,wherein the centerline average surface roughness Ra falls within a range of 1.2 nm to 1.6 nm.4. The magnetic tape according to claim 1 ,wherein the coefficient of friction that is measured on the base portion of the surface of the magnetic layer falls within a range of 0.15 to 0.35.5. The magnetic tape according to claim 1 ,wherein the contact angle for 1-bromonaphthalene that is measured on the surface of the magnetic layer falls within a range of 45.1° to 60.0°.6. The magnetic tape according to claim 1 ,wherein the coefficient of friction that is measured on the base portion of the surface of the magnetic layer falls within a range of 0.20 to 0.35.7. The magnetic tape according to claim 1 ,wherein the contact angle for 1-bromonaphthalene that is measured on the ...

MAGNETIC TAPE HAVING SERVO PATTERN AND CHARACTERIZED MAGNETIC LAYER, AND MAGNETIC TAPE DEVICE

The magnetic tape includes a non-magnetic support; and a magnetic layer including a ferromagnetic powder and a binding agent on the non-magnetic support, in which a magnetic tape total thickness is equal to or smaller than 5.30 μm, the magnetic layer has a servo pattern, a center line average surface roughness Ra measured regarding a surface of the magnetic layer is equal to or smaller than 1.8 nm, and an isoelectric point of a surface zeta potential of the magnetic layer is equal to or greater than 5.5. 1. A magnetic tape comprising:a non-magnetic support; anda magnetic layer including a ferromagnetic powder on the non-magnetic support,wherein a thickness of the non-magnetic support is 3.00 to 4.50 μm,the magnetic layer has a servo pattern,a center line average surface roughness Ra measured regarding a surface of the magnetic layer is equal to or smaller than 1.8 nm, andan isoelectric point of a surface zeta potential of the magnetic layer is equal to or greater than 5.5.2. The magnetic tape according to claim 1 ,wherein the isoelectric point is 5.5 to 7.0.3. The magnetic tape according to claim 1 ,wherein the magnetic layer includes a binding agent including an acidic group.4. The magnetic tape according to claim 3 ,wherein the acidic group includes at least one kind of acidic group selected from the group consisting of a sulfonic acid group and a salt thereof.5. The magnetic tape according to claim 1 ,wherein the center line average surface roughness Ra measured regarding the surface of the magnetic layer is 1.2 nm to 1.8 nm.6. The magnetic tape according to claim 1 , further comprising:a non-magnetic layer including a non-magnetic powder between the non-magnetic support and the magnetic layer.7. The magnetic tape according to claim 1 , further comprising:a back coating layer including a non-magnetic powder on a surface of the non-magnetic support opposite to a surface provided with the magnetic layer.8. A magnetic tape device comprising:{'claim-ref': {'@idref': ...

PERPENDICULAR MAGNETIC RECORDING MEDIA HAVING NOVEL MAGNETIC UNDER-LAYER STRUCTURE

A magnetic medium for perpendicular magnetic data recording having improved corrosion characteristics and reduced surface roughness. The magnetic medium includes an under-layer and a perpendicular magnetic recording layer formed over the under-layer. The under-layer can be formed of MgO and has an oxygen concentration that is greater at the perpendicular magnetic recording layer than it is away from the perpendicular magnetic recording layer. 1. A magnetic medium for perpendicular magnetic data recording , comprising:an under-layer; anda magnetic recording layer formed over the under-layer;wherein the under-layer has a higher oxygen concentration closer to the magnetic recording layer and a lower oxygen concentration away from the magnetic recording layer.2. The magnetic medium as in wherein the under-layer comprises MgO.3. The magnetic medium as in wherein the under-layer comprises MgO and the magnetic recording layer comprises FePt.4. The magnetic medium as in wherein the concentration of oxygen in the under-layer varies in a step wise fashion.5. The magnetic medium as in wherein the oxygen concentration of the under-layer at the magnetic recording layer is about 2 atomic percent greater than it is away from the magnetic recording layer.6. The magnetic medium as in wherein the oxygen concentration of the under-layer at the magnetic recording layer is less than 5 atomic percent greater than it is away from the magnetic recording layer.7. The magnetic medium as in wherein the oxygen concentration of the under-layer at the magnetic recording layer is 1 to 5 atomic percent greater than it is away from the magnetic recording layer.8. The magnetic medium as in wherein the under-layer further comprises a first layer of MgO and a second layer of MgO with the second layer of MgO being located between the first layer of MgO and the magnetic recording layer claim 1 , wherein the second layer of MgO has a higher concentration of oxygen than the first layer of MgO.9. The ...

MAGNETIC RECORDING AND REPRODUCING DEVICE

The magnetic recording and reproducing device includes a magnetic recording medium, a recording element, and a reproducing element. The recording element is an inductive recording element having a first magnetic pole which generates a magnetic field, and a second magnetic pole which is spaced apart from the first magnetic pole with a write gap interposed therebetween, a tip width of the first magnetic pole is substantially the same as a tip width of the second magnetic pole, and a reproducing element width of the reproducing element is 0.2 μm or greater and less than 0.5 μm. In the magnetic recording medium, the number of recesses, which are present in a surface of the magnetic layer and have an equivalent circle diameter of 0.10 μm or greater and less than 0.20 μm, is 100 to 2,000 per area of 40 μm×40 μm. 1. A magnetic recording and reproducing device comprising:a magnetic recording medium;a recording element; anda reproducing element,wherein the recording element is an inductive recording element having a first magnetic pole which generates a magnetic field, and a second magnetic pole which is spaced apart from the first magnetic pole with a write gap interposed therebetween,a tip width of the first magnetic pole is substantially the same as a tip width of the second magnetic pole,a reproducing element width of the reproducing element is 0.2 μm or greater and less than 0.5 μm,the magnetic recording medium has a non-magnetic support, and a magnetic layer containing a ferromagnetic powder, andthe number of recesses, which are present in a surface of the magnetic layer and have an equivalent circle diameter of 0.10 μm or greater and less than 0.20 μm, is 100 to 2,000 per area of 40 μm×40 μm.2. The magnetic recording and reproducing device according to claim 1 ,wherein the number of bright regions having an equivalent circle diameter of 50 nm or greater and less than 100 nm is 7,000 to 25,000 in a binarized image of a secondary electron image obtained by imaging the ...

MAGNETIC RECORDING MEDIUM AND MAGNETIC RECORDING AND REPRODUCING APPARATUS

The magnetic recording medium includes: a non-magnetic support; and a magnetic layer including ferromagnetic powder and a binding agent, wherein the ferromagnetic powder is selected from the group consisting of hexagonal strontium ferrite powder and s-iron oxide powder, and has an average particle size of 5 nm or more and 20 nm or less, wherein the magnetic layer has a servo pattern, and wherein an average area Sdc of magnetic clusters of the magnetic recording medium in a DC demagnetization state, measured by a magnetic force microscope is 0.2×10nmor more and less than 5.0×10nm. 1. A magnetic recording medium comprising:a non-magnetic support; anda magnetic layer including ferromagnetic powder and a binding agent,wherein the ferromagnetic powder is selected from the group consisting of hexagonal strontium ferrite powder and ε-iron oxide powder, and has an average particle size of 5 nm or more and 20 nm or less,wherein the magnetic layer has a servo pattern, and{'sup': 4', '2', '4', '2, 'wherein an average area Sdc of magnetic clusters of the magnetic recording medium in a DC demagnetization state, measured by a magnetic force microscope is 0.2×10nmor more and less than 5.0×10nm.'}2. The magnetic recording medium according to claim 1 ,wherein a ratio Sdc/Sac of the Sdc to an average area Sac of magnetic clusters of the magnetic recording medium in an AC demagnetization state, measured by a magnetic force microscope is 0.8 or more and 2.0 or less.3. The magnetic recording medium according to claim 1 ,wherein the magnetic recording medium is a magnetic tape,wherein the servo pattern is a timing-based servo pattern, and{'sub': 99.9', '0.1', '99.9', '0.1, 'wherein an edge shape of the timing-based servo pattern, specified by magnetic force microscopy is a shape in which a difference L−Lbetween a value Lof a cumulative distribution function of 99.9% and a value Lof a cumulative distribution function of 0.1% in a position deviation width from an ideal shape of the ...

MAGNETIC RECORDING MEDIUM AND MAGNETIC RECORDING AND REPRODUCING APPARATUS

The magnetic recording medium includes: a non-magnetic support; and a magnetic layer including ferromagnetic powder, in which a difference (S−S) between a spacing Smeasured on a surface of the magnetic layer by optical interferometry after n-hexane cleaning under a pressure of 0.5 atm and a spacing Smeasured on the surface of the magnetic layer by optical interferometry after n-hexane cleaning under a pressure of 13.5 atm is 9.0 nm or more.

MAGNETIC TAPE, MAGNETIC TAPE CARTRIDGE, AND MAGNETIC RECORDING AND REPRODUCING APPARATUS

The magnetic tape includes a non-magnetic support, a magnetic layer that includes ferromagnetic powder having an average particle volume of 2,500 nmor less on one surface side of the non-magnetic support, and a back coating layer that includes non-magnetic powder on the other surface side of the non-magnetic support, in which the ferromagnetic powder is ferromagnetic powder selected from the group consisting of hexagonal ferrite powder and ε-iron oxide powder, and a ratio (PSD/PSD) of the magnetic layer and the back coating layer is in a range of 0.0050 to 0.20. A magnetic tape cartridge and a magnetic recording and reproducing apparatus include the magnetic tape. 1. A magnetic tape comprising:a non-magnetic support;{'sup': '3', 'a magnetic layer that includes ferromagnetic powder having an average particle volume of 2,500 nmor less on one surface side of the non-magnetic support; and'}a back coating layer that includes non-magnetic powder on the other surface side of the non-magnetic support,wherein the ferromagnetic powder is ferromagnetic powder selected from the group consisting of hexagonal ferrite powder and ε-iron oxide powder,{'sub': 5 μm-PSDmag', '10 μm-PSDbc', '5 μm-PSDmag', '10 μm-PSDbc, 'a ratio PSD/PSDof a PSDat a 5 μm pitch on a surface of the magnetic layer and a PSDat a 10 μm pitch on a surface of the back coating layer is in a range of 0.0050 to 0.20.'}2. The magnetic tape according to claim 1 ,{'sub': 3 μm-PSDbc', '10 μm-PSDbc', '3 μm-PSDbc', '10 μm-PSDbc, 'wherein a ratio PSD/PSDof a PSDat a 3 μm pitch on a surface of the back coating layer and a PSDat a 10 μm pitch on a surface of the back coating layer is in a range of 0.050 to 0.75.'}3. The magnetic tape according to claim 1 ,{'sub': mag', 'bc', 'mag', 'bc, 'wherein a product Rku×Rkuof a kurtosis Rkuof a surface of the magnetic layer and a kurtosis Rkuof a surface of the back coating layer is in a range of 7.0 to 20.0.'}4. The magnetic tape according to claim 3 ,{'sub': mag', 'bc', 'mag', 'bc, ...

COATING-TYPE MAGNETIC RECORDING MEDIUM FOR HEAT-ASSISTED RECORDING, AND HEAT-ASSISTED MAGNETIC RECORDING APPARATUS AND HEAT-ASSISTED MAGNETIC RECORDING METHOD USING THE SAME

The magnetic recording medium disclosed in the present application includes a non-magnetic support, an undercoat layer, a magnetic layer containing magnetic particles, and a back coat layer. The coercive force Hc of the magnetic layer in the thickness direction at 25° C. is not 4100 oersteds (Oe) or more, and the coercive force Hc of the magnetic layer in the thickness direction at a temperature between 55° C. and 80° C. inclusive is not less than 1200 oersteds (Oe) and not more than 3700 oersteds (Oe). 1. A coating-type magnetic recording medium for heat-assisted recording , comprising:a non-magnetic support; anda magnetic layer containing magnetic particles,wherein a coercive force Hc of the magnetic layer in a thickness direction at 25° C. is 4100 oersteds (Oe) or more, andthe coercive force Hc of the magnetic layer in the thickness direction at a temperature between 55° C. and 80° C. inclusive is not less than 1200 oersteds (Oe) and not more than 3700 oersteds (Oe).2. The coating-type magnetic recording medium according to claim 1 , whereinthe coercive force Hc of the magnetic layer in the thickness direction at 25° C. is 4500 oersteds (Oe) or more, and the coercive force Hc of the magnetic layer in the thickness direction at a temperature between 60° C. and 70° C. inclusive is not less than 1900 oersteds (Oe) and not more than 3500 oersteds (Oe).3. The coating-type magnetic recording medium according to claim 1 , whereinthe coercive force Hc of the magnetic layer in the thickness direction at 25° C. is 10,000 oersteds (Oe) or less.4. The coating-type magnetic recording medium according to claim 1 , whereinthe magnetic particles are composed of ε-iron oxide containing an element other than iron.5. The coating-type magnetic recording medium according to claim 1 , whereina temperature dependence of the coercive force Hc of the magnetic layer in the thickness direction is −30 oersteds (Oe)° C. or less.6. The coating-type magnetic recording medium according to claim ...

MAGNETIC RECORDING MEDIUM AND MAGNETIC RECORDING AND REPRODUCING DEVICE

The magnetic recording medium includes: a non-magnetic support; and a non-magnetic layer including a non-magnetic powder and a magnetic layer including a ferromagnetic powder on the non-magnetic support in this order, in which a vertical squareness ratio is 0.70 to 1.00, a center line average roughness Ra measured regarding a surface of the magnetic layer with an atomic force microscope is equal to or smaller than 2.5 nm, and an interface variation rate between the magnetic layer and the non-magnetic layer in a cross section image obtained by imaging with a scanning electron microscope is equal to or less than 2.5%. 1. A magnetic recording medium comprising:a non-magnetic support; anda non-magnetic layer including a non-magnetic powder and a magnetic layer including a ferromagnetic powder on the non-magnetic support in this order,wherein a vertical squareness ratio is 0.70 to 1.00,a center line average roughness Ra measured regarding a surface of the magnetic layer with an atomic force microscope is equal to or smaller than 2.5 nm, andan interface variation rate between the magnetic layer and the non-magnetic layer in a cross section image obtained by imaging with a scanning electron microscope is equal to or less than 2.5%.2. The magnetic recording medium according to claim 1 ,wherein a void volume of the non-magnetic layer in the cross section image obtained by imaging with a scanning electron microscope is equal to or less than 10.0%.3. The magnetic recording medium according to claim 1 ,wherein the non-magnetic powder of the non-magnetic layer includes carbon black.4. The magnetic recording medium according to claim 3 ,{'sup': '2', 'wherein a specific surface area of the carbon black included in the non-magnetic layer is 280 to 500 m/g.'}5. The magnetic recording medium according to claim 3 ,wherein the non-magnetic layer includes 30.0% by mass or more of the carbon black with respect to a total amount of the non-magnetic powder.6. The magnetic recording medium ...

MAGNETIC TAPE AND MAGNETIC RECORDING AND REPRODUCING DEVICE

The magnetic tape includes a non-magnetic support; and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, in which an absolute value ΔN of a difference between a refractive index Nxy measured regarding an in-plane direction of the magnetic layer and a refractive index Nz measured regarding a thickness direction of the magnetic layer is 0.25 to 0.40, and a logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding a surface of the magnetic layer is equal to or smaller than 0.050. 1. A magnetic tape comprising:a non-magnetic support; anda magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support,wherein an absolute value ΔN of a difference between a refractive index Nxy measured regarding an in-plane direction of the magnetic layer and a refractive index Nz measured regarding a thickness direction of the magnetic layer is 0.25 to 0.40, anda logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding a surface of the magnetic layer is equal to or smaller than 0.050.2. The magnetic tape according to claim 1 ,wherein the difference Nxy−Nz between the refractive index Nxy and the refractive index Nz is 0.25 to 0.40.3. The magnetic tape according to claim 1 ,wherein the logarithmic decrement is 0.010 to 0.050.4. The magnetic tape according to claim 1 , further comprising:a non-magnetic layer including a non-magnetic powder and a binding agent between the non-magnetic support and the magnetic layer.5. The magnetic tape according to claim 1 , further comprising:a back coating layer including a non-magnetic powder and a binding agent on a surface of the non-magnetic support opposite to a surface provided with the magnetic layer.6. A magnetic recording and reproducing device comprising:{'claim-ref': {'@idref': 'CLM-00001', 'claim 1'}, 'the magnetic tape according to ; and'}a magnetic head. This application claims priority under 35 U.S.C 119 to ...

MAGNETIC TAPE AND MAGNETIC TAPE DEVICE

The magnetic tape includes a non-magnetic support; a non-magnetic layer including a non-magnetic powder and a binding agent on the non-magnetic support; and a magnetic layer including a ferromagnetic powder and a binding agent on the non-magnetic layer, in which a total thickness of the non-magnetic layer and the magnetic layer is equal to or smaller than 0.60 μm, the magnetic layer has a servo pattern, and an isoelectric point of a surface zeta potential of the magnetic layer is equal to or greater than 5.5. 1. A magnetic tape comprising:a non-magnetic support;a non-magnetic layer including a non-magnetic powder and a binding agent on the non-magnetic support; anda magnetic layer including a ferromagnetic powder and a binding agent on the non-magnetic layer,wherein a total thickness of the non-magnetic layer and the magnetic layer is equal to or smaller than 0.60 μm,the magnetic layer has a servo pattern, andan isoelectric point of a surface zeta potential of the magnetic layer is equal to or greater than 5.5.2. The magnetic tape according to claim 1 ,wherein the isoelectric point is 5.5 to 7.0.3. The magnetic tape according to claim 1 ,wherein the binding agent is a binding agent including an acidic group.4. The magnetic tape according to claim 3 ,wherein the acidic group includes at least one kind of acidic group selected from the group consisting of a sulfonic acid group and a salt thereof.5. The magnetic tape according to claim 1 ,wherein the total thickness of the non-magnetic layer and the magnetic layer is 0.20 μm to 0.60 μm.6. The magnetic tape according to claim 1 , further comprising:a back coating layer including a non-magnetic powder and a binding agent on a surface of the non-magnetic support opposite to a surface provided with the magnetic layer.7. A magnetic tape device comprising:{'claim-ref': {'@idref': 'CLM-00001', 'claim 1'}, 'the magnetic tape according to ;'}a magnetic head; anda servo head. This application claims priority under 35 U.S.C. 119 ...

MAGNETIC TAPE CARTRIDGE AND MAGNETIC TAPE DEVICE

Provided is a magnetic tape cartridge of a single reel type in which a magnetic tape is wound around a reel, in which the magnetic tape includes a non-magnetic support and a magnetic layer containing a ferromagnetic powder, and has a tape thickness of 5.3 μm or less, the magnetic layer includes a plurality of servo bands, and a difference (G−G) between a servo band interval Gin a range of 49 m to 51 m from a tape inner end and a servo band interval Gin a range of 49 m to 51 m from a tape outer end is −3.9 μm to 1.1 μm as a value measured on 100th day from a date of magnetic tape cartridge manufacture. 1. A magnetic tape cartridge of a single reel type in which a magnetic tape is wound around a reel ,{'sub': inner', 'outer', 'inner', 'outer, 'wherein the magnetic tape includes a non-magnetic support and a magnetic layer containing a ferromagnetic powder, and has a tape thickness of 5.3 μm or less, the magnetic layer includes a plurality of servo bands, and a difference G−Gbetween a servo band interval Gin a range of 49 m to 51 m from a tape inner end and a servo band interval Gin a range of 49 m to 51 m from a tape outer end is −3.9 μm to 1.1 μm as a value measured on 100th day from a date of magnetic tape cartridge manufacture.'}2. The magnetic tape cartridge according to claim 1 ,wherein a tape width deformation rate of the magnetic tape measured within 20 minutes, after the magnetic tape is stored in a dry environment at a temperature of 52° C. for 24 hours in a state where a load of 100 g is applied in a tape longitudinal direction and the load is removed, is more than 400 ppm, and the tape width deformation rate is a value obtained by starting the storage on 100th day from the date of magnetic tape cartridge manufacture.3. The magnetic tape cartridge according to claim 1 ,wherein the magnetic tape includes a non-magnetic layer containing a non-magnetic powder between the non-magnetic support and the magnetic layer.4. The magnetic tape cartridge according to ...

MAGNETIC TAPE CARTRIDGE AND MAGNETIC TAPE DEVICE

In the magnetic tape cartridge, a tape has a tape thickness of 5.3 μm or less, and a difference W−Wbetween a tape width Wat a position of 50 m±1 m from a tape inner end and a tape width Wat a position of 50 m±1 m from a tape outer end is 4.1 μm to 19.9 μm as a value measured on 100th day from a date of magnetic tape cartridge manufacture, and a difference G−Gbetween a servo band interval Gin a range of 49 m to 51 m from the tape inner end and a servo band interval Gin a range of 49 m to 51 m from the tape outer end is −3.9 μm to 0.0 μm as a value measured on 100th day from the date of magnetic tape cartridge manufacture. 1. A magnetic tape cartridge of a single reel type in which a magnetic tape is wound around a reel ,wherein the magnetic tape includes a non-magnetic support and a magnetic layer containing a ferromagnetic powder, and has a tape thickness of 5.3 μm or less,the magnetic layer includes a plurality of servo bands,{'sub': inner', 'outer', 'inner', 'outer, 'a difference W−Wbetween a tape width Wat a position of 50 m±1 m from a tape inner end and a tape width Wat a position of 50 m±1 m from a tape outer end is 4.1 μm to 19.9 μm as a value measured on 100th day from a date of magnetic tape cartridge manufacture, and'}{'sub': inner', 'outer', 'inner', 'outer, 'a difference G−Gbetween a servo band interval Gin a range of 49 m to 51 m from the tape inner end and a servo band interval Gin a range of 49 m to 51 m from the tape outer end is −3.9 μm to 0.0 μm as a value measured on 100th day from the date of magnetic tape cartridge manufacture.'}2. The magnetic tape cartridge according to claim 1 ,wherein a tape width deformation rate of the magnetic tape measured within 20 minutes, after the magnetic tape is stored in a dry environment at a temperature of 52° C. for 24 hours in a state where a load of 100 g is applied in a tape longitudinal direction and the load is removed, is 400 ppm or less, and the tape width deformation rate is a value obtained by starting ...

記録面のエンボスメントを減少する裏側を備えた磁気記録媒体

【課題】磁気記録媒体の記録面のエンボスメントを減少しながら、磁気記録媒体の耐久性および摩擦特性を改善するべく構成された裏側を有する磁気記録媒体を提供する。 【解決手段】基材と、磁気側と、裏側と、を含む磁気記録媒体。基材は、第１の表面と、第１の表面の逆側の第２の表面を画定している。磁気側は、基材の第１の表面に形成されていて、記録面を画定している。裏側は、基材の第２の表面にコートされ、記録面のエンボスメントを減少するように構成されている。裏側は、基材の逆側の裏側表面を画定している。裏側表面のスキューは約０．５未満、尖度は約４．０未満である。 【選択図】図３

MAGNETIC TAPE CARTRIDGE AND MAGNETIC RECORDING AND REPRODUCING DEVICE

In the magnetic tape, a maximum value of magnetic tape deformation amounts after storage in each of five environments for 1 year is 0.50 μm or less, a rate of a change of magnetic tape deformation amount with respect to a change in relative humidity obtained from the five magnetic tape deformation amounts is 0.0001 μm/% to 0.0500 μm/%, and a rate of a change of the magnetic tape deformation amount with respect to a change in temperature obtained from the five magnetic tape deformation amounts is 0.0010 μm/° C. to 0.1000 μm/° C. 1. A magnetic tape cartridge comprising:a magnetic tape which is wound around a cartridge reel and accommodated in the magnetic tape cartridge,wherein the magnetic tape includes a non-magnetic support, and a magnetic layer containing a ferromagnetic powder,the magnetic layer includes a plurality of servo bands,a maximum value of the following five magnetic tape deformation amounts ofa magnetic tape deformation amount after storage for 1 year in an environment of a temperature of 16° C. and relative humidity of 20%,a magnetic tape deformation amount after storage for 1 year in an environment of a temperature of 16° C. and relative humidity of 80%,a magnetic tape deformation amount after storage for 1 year in an environment of a temperature of 26° C. and relative humidity of 80%,a magnetic tape deformation amount after storage for 1 year in an environment of a temperature of 32° C. and relative humidity of 20%, anda magnetic tape deformation amount after storage for 1 year in an environment of a temperature of 32° C. and relative humidity of 55%is 0.50 μm or less,a rate of a change in magnetic tape deformation amount with respect to a change in relative humidity, which is obtained from the five magnetic tape deformation amounts, is 0.0001 μm/% to 0.0500 μm/%, anda rate of a change in magnetic tape deformation amount with respect to a change in temperature, which is obtained from the five magnetic tape deformation amounts, is 0.0010 μm/° C. to 0 ...

磁気記録媒体

(57)【要約】本公報は電子出願前の出願データであるた め要約のデータは記録されません。

磁気記録媒体

(57)【要約】本公報は電子出願前の出願データであるた め要約のデータは記録されません。

磁気記録媒体

(57)【要約】本公報は電子出願前の出願データであるた め要約のデータは記録されません。

磁気記録媒体

磁気記録媒体

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磁気テープおよびその製造方法

Data storage media

Optical recording tape has a backcoat providing a surface texture designed to impart high static friction between the opposite faces of the tape to enable the tape to maintain pack integrity during storage and transport.

Magnetic recording medium

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Magnetic recording medium

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Magnetic tape

Magnetic tape and method of manufacturing the same

Magnetic recording media

Magnetic recording tape, manufacturing method thereof, magnetic recording tape cartridge

Magnetic recording medium

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Patent JPH0445887B2

Patent JPS5843817B2

Magnetic recording tape having a backcoat and specified edge profile

In the present invention, the anti-scrapability of the back layer of a magnetic recording medium is improved to reduce the frequency of occurrence of powder fall onto the surface of the magnetic layer and clogging between the magnetic head and the surface of the magnetic layer. As a result, a magnetic recording medium which is extremely less susceptible to dropout can be provided. A novel tape-shaped magnetic recording medium is provided which is obtained by longitudinally slitting a nonmagnetic support having on one side thereof a magnetic layer comprising a ferromagnetic powder dispersed in a binder and on the other side a back layer, wherein the edge face of said back layer doesn't protrude from the vertical line tangent to the highest protrusion on the slit section of said nonmagnetic support.

Magnetic tape

Magnetic recording medium

Magnetic recording medium

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Magnetic recording medium

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Magnetic recording medium

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Production of magnetic recording medium

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Magnetic recording medium

(57)【要約】本公報は電子出願前の出願データであるた め要約のデータは記録されません。

Magnetic recording medium

(57)【要約】本公報は電子出願前の出願データであるた め要約のデータは記録されません。

Magnetic tape

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Magnetic recording medium

Magnetic tape

本发明实现适合于数字信号的记录重放、长时间记录用的薄磁带。通过使非磁性支撑体(基膜)的宽度方向(TD)的杨氏模量在15.6GN/m 2 以上、19.6GN/m 2 以下,提供一种可减少磁带行走时等发生的磁带损伤、维持磁带和磁头的良好接触状态的磁带。

Magnetic recording medium

Magnetic disc and its production

(57)【要約】本公報は電子出願前の出願データであるた め要約のデータは記録されません。

Magnetic recording tape and its manufacturing method and magnetic recording tape drum

本发明旨在提供一种磁性记录带等，其允许磁带稳定地高速行进，同时维持磁头和磁带之间的距离保持窄的状态。本发明提供了一种具有至少包括磁性层的多层结构的磁性记录带。磁带具有5.6μm以下的总厚度，并且包括设置在磁性层的表面中的多个凹部。通过将每个凹部的深度D1除以磁性层的厚度D2获得的值为15％以上。磁性层垂直取向，并且在没有退磁校正的情况下具有65％以上的垂直取向度。磁性层包括形成在其中的多个凹部，多个凹部的每个的深度为磁性层的厚度的20％以上，并且磁性层的每6,400μm 2 的表面积的凹部的数量为55个以上。本发明还提供了一种磁性记录带的制造方法。

Magnetic recording medium

Magnetic recording medium, magnetic tape cartridge and magnetic recording/reproducing apparatus

【課題】六方晶ストロンチウムフェライト粉末およびε−酸化鉄粉末からなる群から選ばれる強磁性粉末を磁性層に含み、優れた電磁変換特性を発揮することができる磁気記録媒体を提供すること。【解決手段】非磁性支持体と強磁性粉末を含む磁性層とを有する磁気記録媒体。上記強磁性粉末は六方晶ストロンチウムフェライト粉末およびε−酸化鉄粉末からなる群から選択される強磁性粉末であり、上記磁性層の表面における磁性凸部の高さの標準偏差は０．５〜２．５ｎｍの範囲である。上記磁気記録媒体を含む磁気テープカートリッジおよび磁気記録再生装置。【選択図】なし

Magnetic tape

MAGNETIC RECORDING MEDIUM TREATED WITH ANTIFUNGAL AGENT

MAGNETIC RECORDING MEDIUM PROCESSED BY AN ANTIFUNGAL AGENT

L'invention a pour objet un milieu d'enregistrement magnétique comprenant un support non magnétique 1 et une couche magnétique 2 appliquée sur une face dudit support non magnétique et une couche dorsale 3 sur une seconde face dudit support, contenant un agent antifongique dans la couche magnétique, dans une couche appliquée sur la couche magnétique ou dans la couche dorsale. Le milieu magnétique selon l'invention comprend au moins un agent antifongique choisi parmi la p-tolyldiiodométhylsulfone, l'alcool 2,3,3-triidoallylique, le 2-méthoxycarbonylaminobenzimidazole et les sels de 2-méthoxycarbonylaminobenzimidazolium. Applications : fabrication de milieux magnétiques tels que films, bandes, feuilles, disques etc. pour l'utilisation dans les régions chaudes et humides. The invention relates to a magnetic recording medium comprising a non-magnetic medium 1 and a magnetic layer 2 applied on one side of said non-magnetic medium and a backing layer 3 on a second side of said medium, containing an antifungal agent in the layer. magnetic, in a layer applied on the magnetic layer or in the backing layer. The magnetic medium according to the invention comprises at least one antifungal agent chosen from p-tolyldiiodomethylsulfone, 2,3,3-triidoallyl alcohol, 2-methoxycarbonylaminobenzimidazole and 2-methoxycarbonylaminobenzimidazolium salts. Applications: manufacture of magnetic media such as films, tapes, sheets, discs etc. for use in hot and humid areas.

MAGNETIC RECORDING DISC AND MANUFACTURING METHOD THEREOF

Magnetic recording media having a backside coating which includes multicomponent, nonmagnetic particles

A magnetic recording medium comprising a support having two major surfaces, a magnetic layer provided on one major surface of the support, and a backside coating provided on the other major surface of the support wherein the backside coating comprises nonmagnetic, multicomponent particles dispersed in a polymeric binder. The nonmagnetic, multicomponent particles are comprised of a first component having a Mohs hardness equal to or less than 7 and a second component having a Mohs hardness greater than 7.

Magnetic recording material

A magnetic recording material, which is provided on one surface of a substrate with a magnetic recording coating, is characterised in that it is provided on the other surface of this substrate with a rear coating, which has been obtained by dispersing a non-magnetic powder in a binder, to which there has been added a radiation-sensitive curing synthetic resin which contains a fatty acid or a mixture of a fatty acid and a fatty acid ester.

Magnetic recording medium

ABSTRACT OF THE DISCLOSURE A magnetic recording medium comprising a magnetic layer on one surface of a non-magnetic base and a back coating on the other surface thereof which is not thicker than 2 µ and which contains inorganic particles and a binder is disclosed. The inorganic particles have an average size between 0.02 and 5 µ and a Mohs hardness of 2.5 to 9.0, and the surface of the back coating has a center line average roughness (Ra) of 0.024 or less and the surface of the magnetic layer has a center line average roughness (Ra) of 0.02.

Magnetic recording medium

Magnetic recording medium

A magnetic recording medium comprises a non-magnetic support on one side of which is formed a magnetic recording layer, and a back coating layer formed on the other side of the support. The coating layer comprises 25-400 pts. wt. of a carbon black dispersed in 100 pts. wt. of a resin binder. The carbon black has a colouring power of not less than 90 at pH 2.0-8.5 and an average size of 0.01-0.05 micrometer. The resin binder is a vinyl chloride resin, a urethane resin or a nitrocellulose.

Magnetic recording medium

Flexible magnetic recording carrier with back layer

The invention relates to flexible, magnetic recording carriers essentially comprising a web-form (sheet-form) nonmagnetic substrate, a magnetic layer applied to the principal side of the web-form substrate, and a back layer (backing) formed on the opposite principal side of the substrate from a polymeric binder and nonmagnetic fillers and supporting pigments.

Magnetic recording medium

A magnetic recording medium comprising a non-magnetic support having provided thereon a magnetic layer on one side and a backing layer on the other side, wherein the backing layer contains (1) non-magnetic powders containing carbon black having an average particle diameter of from 0.1 to 1 μm; (2) two or more binders wherein (a) at least one of the binders is a resin having a 100% modulus of from 15 to 150 kg/cm 2 in an amount of from 50 to 95 wt % based on the total amount of the binders in the backing layer, and (b) the rest binder(s) is/are a resin other than the resin having a 100% modulus of from 15 to 150 kg/cm 2 , and the weight ratio of all the non-magnetic powders to all the binders in the backing layer is from 300:100 to 40:100; and (3) a polyisocyanate in an amount of from 15 to 40 wt % based on the total amount of the binders in the backing layer.

Magnetic recording medium

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Audio magnetic recording tape

Magnetic recording medium

Magnetic recording medium

Provided is a magnetic recording medium that is employed to particular advantage as an external recording medium for the recording of digital data, having a layer in which carbon black is well dispersed, and in particular, a backcoat layer. A magnetic recording medium comprising a layer comprising a granular substance and a binder, wherein said layer comprises the compound denoted by general formula (I) below. A—N═N—X—Y  General formula (I) (in general formula (I), A denotes a component forming an azo dye with X—Y; X denotes a group selected from among the divalent connecting groups denoted by the structural formulas below: (in general formula (II), Z denotes a lower alkylene group; —NR 2 denotes a lower alkylamino group or a nitrogen-comprising five-membered or six-membered heterocyclic ring; and a denotes 1 or 2)).

Magnetic tape cartridges and magnetic tape devices

Magnetic recording medium - having a thermoplastic carrier backed with a smooth coating

A magnetic recording medium consists of a thermoplastic carrier material on the surface of which a magnetic coating is applied and which is coated on the reverse side with a material having a surface resistivity not >109 ohms and a smooth surface of roughness 0.2-1.0 mu m. The medium is used partic. for videotapes. The medium gives a better ratio of signal to background noise has a higher picture recording sensitivity and permits use of non-rotating carrier pins.

Magnetic recording medium

A magnetic recording medium having an excellent electromagnetic property with a low frictional magnetic layer surface which comprises a base material and a magnetic layer provided thereon, said magnetic layer comprising magnetic powder, a resinous binder and graphitized carbon black powder, optionally with non-graphitized carbon black powder.

Magnetic recording medium, magnetic recording and reproducing apparatus, magnetic tape cartridge, and magnetic tape cartridge group

In the magnetic recording medium, a number distribution A of a plurality of bright regions, based on equivalent circle diameters thereof, in a binarized image of a secondary electron image obtained by imaging a surface of the magnetic layer by a scanning electron microscope at an acceleration voltage of 5 kV and a number distribution B of a plurality of dark regions, based on equivalent circle diameters thereof, in a binarized image of a secondary electron image obtained by imaging a surface of the magnetic layer by a scanning electron microscope at an acceleration voltage of 2 kV respectively satisfy a predetermined number distribution.