SELF-LUBRICATING ANTI-FRICTION COMPOSITION.

The invention concerns a self-lubricating anti-friction composition. The erfindungsgemiissen compositions one knows ftir the production yon construction units of the friction units, for example GMT camps, uses, those hauptsiichlich without lubricants or with its delimitation (season lubricants, unique when assembling, periodic with repair) claimant werden.

Application yon pure polymers ffir the production yon construction units of the friction units corresponds to the demands, which are made in mechanical engineering on working reliability and life span of the sliding bearings, mobile seals and other machine units, not. That is due to relatively low abrasion resistance yon polymers and Stabilitiit during effect of the AtmosphS.renfaktoren. The friction units are often operated in corrosion-active media, which causes the Vefletzung of the Metalloberfliichen yon construction units, and as consequence erh6hten VerschMss coupled polymere construction units. ) khnliche injuries k6nnen when long storage or preservation of the machines and mechanisms develop, which enthaIten coupled construction units from polymer composition and metallic construction units (metallic-polymere units). In this case the corrosion can cause for example a metal wave the keying of the unit, which to their Zerst6rung with the enterprise ffihrt.

It is well-known a self-lubricating anti-friction composition, those from 70-99,9 mA. - % PP and 0.1-30 mA. - % polyolefin exists (US-PS No. 3,726,945, class C 08 G 41/04). With the friction a Schmelzdiinnschicht develops yon for polyolefin, reduction of the coefficient of friction and the Erh6hung of the abrasion resistance gewiihrleistet on the Oberflgche of the construction unit from soIcher composition. This effect appears however only with sufficiently high loads and running speeds. Darfiber outside gew hrleistet the erwfitmte composition the corrosion protection of the coupled metal construction units with the work of the friction unit in aggressive media nicht.

It is well-known a self-lubricating anti-friction composition, those from 100 Gew. - T. PP, 10-30 Gew. - T. powders yon burned 01koksen and 10-15 Gew. - T. Sehmier61 exists (SU-PS 531,831, C 08 L 77/00, veriSffentlieht 1976).

This composition is certain fiir the production yon friction units, which are sufficiently well yon the effect of the environment (Feuehte, solar radiation among other things) gesehfitzt and work at relatively low temperatures (hfehstens 100 °C). Due to Uberlastungen and b.e.i unstable Reibungsverhiiltnissen develops however local Uberhitzungen, which aktivieten the dismantling and the oxidation yon polymer materials, which to their accelerated aging and to the premature loss yon friction units ffihrt.

It is also a self-lubricating anti-friction composition on the PP basis admits (SU-PS No. 704,958, class C 08 J 5/16, vedSffentlicht 1979), those among other things from Schmier61 (10-15 mA. - %), dry lubricant Polytetrafluoriithylen (I 0-15 mA. - %) - and Athylendiamintetraessigsiiure (0.5-0.7 mA. - %) exists. The composition exhibits high ptiysikalisch mechanical characteristics and wear barness and low coefficient of friction. During continuous effect yon erh6hten temperatures (100 '- C) worsen however physical-mechanical characteristic data of the composition. In addition the composition is not befiihigt, the corrosion processes to the Oberfliiche of the metallic Gegenk6rpers with the enterprise or with the storage of the metallic-polymere friction unit too hemmen.

The Erfmdung is appropriate the task edge of course to develop a selbstsclmaierende anti-friction composition the products out welchel sufficiently high physikalisch-mechanisehe characteristics and wear barness with 1iingerer effect yon for high temperatures and aggressive media beibehalten.

The task becomes thereby gel6st that it will vorgesehlagen a selbstsehmierende anti-friction composition, the PP, Sehmier61 and dry Sehmierstoff enthilt.

The erfindungsgemfisse anti-friction composition is gekennzeiehnet dadutch that it exhibits groups - NOz, C = O, or one the electron acceptor effect, containing groups - as troekenen lubricant graphite and a corrosion inhibitor of the electron donor effect, containing NH2, - OH and polyolefin enthiilt, whereby the quantitative composition in mA. - %, as is fotgt:

Polyolefin 5-15 Sehmier61 3-10 graphite 5-10 corrosion inhibitor 1-5 PP remainder on 100 the erfindungsgemiisse anti-friction composition points stable physical-mechanical and anti-friction particularly clinging with erh6hten temperatures (until °C) up, the intergranular corrosion in friction units, which are operated continuously or periodiseh and long preservation time to have, erm6glieht it, the Intensitiit of the korrosionsmechanisehen wear of the coupled metallic construction units of a friction unit herabzusetzen.

, restrains 150 Owing to the presence in the composition yon polyolefin becomes the Selbstsehmierungsbetrieb with erh6hten Gesehwindigkeiten and loads (high temperature enterprise) secured. The presence in the composition of Schmier61 erm6glicht it to bring self-lubricating characteristics with the very low-temperature enterprise for validity (to 80-100 °C). Being present graphite in the composition erm6glieht it to lower the coefficient of friction and the abrasion resistance of the composition to erh6hen. The Einfiihrung of a schwerl6slichen of corrosion inhibitor into the composition permits it to decrease the Intensitfit of the corrosion processes to the Oberfliiehe of the coupled metal construction unit with the work of a friction unit in aggressive media (Wasser16sungen yon electrolytes, Siiuren, caustic solutions) the gewiihlten types yon corrosion inhibitors exhibits fibre outside good anti-oxidation characteristics regarding the material of the polymer basis of the composition - PP -, which it erm6glieht, with the help of a composition component (the corrosion inhibitor) simultaneously Thermodestruktion of the polymer composition and wfihrend the enterprise of the friction unit at the border Polymerkomposition Metall> > running corrosion processes more passively too machen.

The Massenverhiiltnis between the polyolefin and the Flfissigphasenkompositionskomponente (Sehmier61 + corrosion inhibitor) should be 1:0,8 to 1:1. This Verhiiltnis is gewfihlt from the following Grtinden. As well known becomes with the Ffillung of polyolefin with the Flfissigphasenplastifikator (40-50 mA. - %) and following melts of the mixture a Kolloidl6sung in an educated manner, which transforms with the Kiihlung into gel, i.e. into a system with not s0 of completed phase separation. The formed Polymergerfist has kommunizicrende cells (pores) with a Gr6sse yon to 30 GM, in which see the Flfissigkeit (Plastifikator) finds. Owing to the Syniirese regelmiissiger Flfissigkeitsaustritt from the pores is gesiehert. Plastifikator serves Schmier61 and sehwerI6slichem Korrosionsinhibitor.<br in the orfindungsgem issen composition a Flfissigphasengemisch yon/> The polymer gel is distributed gleiehmiissig fibre the whole volume of the erfindungsgcmfissen composition, and therefore the erwiihnte Flfissigphasenkomponente regelmiissig z0 on the Oberflfiche of the product will withdraw, which is made of the erfindungsgemiissen composition. With the consumption of the Flfissigphasenkomponente in the friction zone, which is away-carried yon for the metallic Gegenk Srper, the obenbesehriebene process of the F6rderung von Inhibitorschmier61 from the material volume of the product repeats itself on the Reibungsoberflfiche. Thus become the self adjustment as well as the friction, and anti-corrosion particularly clinging of the composition aufrechterhalten.

It is unzweckmfissig, polyolefin in a quantity of under 5 mA. - % into the composition einzuffihren, see thereby the self-lubricating characteristics of the composition weft being beeintriichtigt. The Erh6hung of the polyolefin content fibre 15 mA. - ffihrt % for the degradation of the physical-mechanical characteristic data of the composition. From fihnliehen Grtinden the presence in the composition of the Flfissigphasenkomponente (Schmier61 + corrosion inhibitor) is determined. As it was already hnt erw, the quantity was to stand yon for Flfissigphasenffiller in certain proportion to polyolefin content. Which concerns the corrosion inhibitor, it is not advisable, it in a quantity yon under i mA. - einzuffihren %, because dadurctt those are beeintriichtigt anti-corrosion particularly clinging of the composition, and the Einffihrung of inhibitor in a quantity yon fibre 5 mA. - is unzweckmfissig %, because too no Erh6hung yon anti-corrosion characteristics ffihrt.

The Einfiihrung yon graphite in a quantity yon under mA. - % sets the anti-corrosion characteristics of the composition down (the coefficient of friction and the wear erhfht).

The Ftillung of the composition with graphite in a quantity yon fibre 10 mA. - % fiihrt to the Beeintriichtigung that Eigenschaften.<br physikaliseh mechanisehen/> The erfindungsgerniisse anti-friction composition is manufactured as follows. The Polyamidgran ulat is &gt before at a temperature yon 100 to 110 '; C within yon 2 his 3 hours dried (the content of fliichtigen components is not 0.10-0.15 mA. - % fibersehreiten). Danaeh are eingeffihrt polyolefin granulates and graphitic powder, and the Gemiseh is gxlt verrfihrt. Then one fiigt Schmier61 also before in him gel6sten corrosion inhibitor too. The received mixture is verriihrt in a mixture of the arbitrary type, for example in the Trommelmfihle a mass homogeneous up to the achievement. The composition becomes products after the HoehMstungsverfahren of the extruding and/or the pressure pouring at a temperature yon 220 to 270 °C (abh ngig yon PP places) verarbeitet.

If after the operating conditions of the product from the erfindungsgemiissen composition the creation of the be668 774 triichtlichen resources of the Flfissigphasenkomponente fibre is nieht necessary the whole volume of the product, it is advisable to manufacture the product as follows. It semi-finished material from the Kompositionskornponenten with firm phase (the mixture from PP, polyolefin and graphite) for example sew the pressure pouring procedure formed. Then they are fed into the BehSlter, which is gefiillt with the F1iissigphasenkomponente, which a Gemiseh from Schmier61 and sehwerl6slichem corrosion inhibitor in a Verhiiltnis represents yon to 2:1 to 3:1. The temperature of the erwiihnten Fliissigphasenkomponente soil h6her as the fusing temperature of the polyolefin used in the composition its, but nieht 80-90% of the value of the Sehmelztemperatur of the PP, which is taken as composition basis, fibre-walks. The stop time hfingt yon the necessary Einffihrungstiefe of the Sehmier61s off. Thus the Durchtriinkungsgesehwindigkeit maeht with depths to 500 GM yon 8 to 10 GM/min out. After the Durchtriinken the composition of the Oberflfiehensehicht of the product of the Zusalnmensetzung entsprieht invention in accordance with tssen Komposition.

As PP one can use in the erfindungsgemiissen composition:

Polykaproamid (casting resin) - the product of hydrolytic polymerization yon A-Kaprolaktam in present yon catalysts, in the form of granulates with a diameter yon 1 to 5 mm, Diehte p = I 130 kg/m3, Sehmelztemperatur Tsehm = 215 C, zerst6rende tensile stress gz = 55-77 MPa, zerst6rende compression stress Crdr = 100-150 MPa; Casting PP - the product of the polycondensation of the salt yon hexadecimal hexadecimaldiaminehexadecimal diamine and Sebazinsiiure, in the form of granular with a diameter yon 3 to 5 RAM, P = 1140 kg! m3, Ts TC = 252-260 C, = 80 MPa; glasfasergeffillter PP - Polykaproamidharz, gefiillt with glass fibers with a Durehmesser from 9 to 11 grn in a quantity of 30 mA. - %, in form yon granular with eihem Durehmesser yon 3 to 9 mm, p= 1360 kg/m3, Tschm = 217 '°C, z = 115 MPa, Crar = 180 MPa.

As polyolefins recommends it see, in the composition for example Hoehdruckpolyiithylen (9 = 900-939 kg/m3), polypropylene (p = 900-910 kg/m3) too verwenden.

As Schmier61e one can for example Mineral61e, with which Buehstaben A, b, C marks, uses:

A Mineral61 of the selective refining without Zusfitze, which will receive from sehwefelarmen paraffinhaltigen and paraffin-poor Erd61on, with the following main characteristic data: Density with 20 °C 0.89 g/cm3, Viskosit t with 20 'C 14 ' 10,6 mZ/s, ash content nieht more than 0.003%, Siiurezab_l 0.25 mg KOH/g, setting point minus 30 C, flash point in closed crucible 200 °C; b - Mineral61 of the Selsktivraffination without Zusiitze, which will receive from schwefelarrnen Erd61en, with the following main characteristic data: Density with 20 °C 0.897 g/cm3, Viskositiit with 20 °C 20,5.10.6 m2/s, Asehegehalt no more than 0.003%, Siiurezahl 0.03 mg KOH/g, setting point minus 18 °C, flash point in gesehlossenem Tiege1250 °C; e - Destillatmineral61 with high cleaning temperature with the following main characteristic data: Density with 20 °C 0.894 g/cm, Viskositiit with 20: C 49 cSt, with 50 “C 20 " 10-6 m2/s, stick temperature minus 45 °C, flaming temperature in open crucible 163 °C.

As Sehmier61e k6nnen also Silikon61e (siliziumorganisehe Flfissigkeiten) - Organosiloxanpolymere with low molecular mass to be used, those the Flfissigkeitseigenschaften within the far temperature range maintained k6nnen, ehernisch inertly, rustproof, 16slich in aromati668 774 schen and chlorinated themselves aliphatic hydrocarbons are good and with the Olen on Erd61basis vertragen.

From SilikonSlen one can use for example the following, with the letters e, f, g designation:

e - Polyiithylsiloxanfliissigkeit, density with 20 °C 0.97 g cm3, Viskositiit with 20 °C 42-10-6 m° /s, boiling point 250 °C, flash point in open crucible 170 °C, specific Wiirmekapazit it with 20 °C 0.445 kkal/(kg degrees); fPolyiithylsiloxanfliissigkeit, density with 20 °C 1.08 g cm3, Viskositiit with 20 °C 20-10-6 ma/s, setting point minus °C, boiling point 250 °C, flash point in the open crucible 265 °C, specific Wiirrne with 20 °C, 0.392 kkal/(kg. Degree); gPolymethylphenylsiloxanfliissigkeit, density with 20 °C 1.18 g/cm3, Viskositiit with 20 °C 54 " 10-6 m2/s, setting point minus 36 °C, boiling point 360 °C, specific Wiirmekapazit/it with 20 °C, 0.34 kcal/(kg degrees).

From 6115slichen corrosion inhibitors in the existence of the erfindungsgemiissen composition are [groups - NO2, C = O, and yore type of acceptor, containing groups - nhibitoren NH2, - OH, effektiv.

from the type of donor, containing As corrosion inhibitors of the donor effect for example the following products, designation with the letters A, kSnnen B, C, to be used:

A selective-cleaned nitrated Mineral51, thickens with paraffin (10 mA. - %), a 51ige Fliissigkeit is darkly color with a density yon 0.96 g/cm3 with 20 °C, a Viskositiit yon 100 cSt with 20 °C and 30 cSt with 100 °C, einero ash content of 3,5%, is in MineralSlen and organic LSsungsmitteln 15slich, enthfilt groups - NO2; B - Diiithyldihexadezylammoniumnitrat [(C2H5) 2N (C16H33)]NO2; C - Olefinsfiurefithylendiaminmonoamid O II NH2CH2CH2NHO - C17H33 Ats corrosion inhibitors of the acceptor effect one can use for example the following Zus itze, designation with the letters D, E, F:

D - Salt mixture yon Dizyklohexylamin (43 mA. - %) with synthetic fat iuren with 10 to 20 C-atoms (57 mA. - %) of the general formula (C H11) 2 NH OnH2 n+ 1COOH, the one paste-like product with a density yon 0.92 g/cm3 with 20: C, a fusing temperature yon 15-20 represents, which is into Olen and organic L6sungsmitteIn 16slich; E - Salt of Zyklohexylamin and synthetic Fettsiiuren with 7 to 11 C-atoms of the general molders (CnH2n +1COOHC6H11NH2), paste-like material, hay-brown, the setting point minus 12 ': 'C, 16st itself in alcohol, Olen, gasoline, acetone; F - Condensation product of Alkenylbernsteinsiiureanhydrid and urea (light brown Fliissigkeit with a density of 0,89 g/cm3 with 20 °C, with a Viskositiit yon cSt with 50: C, 16st in Olen and L6sungsmitteln, enthilt itself - NH2 - groups).

The damage mechanism of the lnhibitoren exists in the following. The inhibitors yore type of donor ibertragen, after they arrived at the Oberfliiche, fiberfltissige electrons on the Gegenk6rper, and form thus on its Oberfliiche chemosorption connections. The inhibitors of the acceptor effect form, taking up MetaUionen, also chemosorption layers, which schiitzen D e Obcrfl iche of the GegenkiJrpers against the corrosion. The gewiihlten in .hibitorengruppen contains usserdem anti-oxidising agent - materials, which restrain a Wiirmeoxydationsdestruktion of Polymeten. The corrosion inhibitors of the type of donor contain anti-oxidising agents - of reducing agents: organisehe sulfides, Selenide and fat-aromatic Phosphite, which react to PP without education of free radicals with groups of hydraulic peroxides yon. The acceptor inhibitors contain aromatic amines and alkylated phenol, which block the oxidation process yon PP, i.e. with active free radicals reagieren.

For the illustration of the invention some compositions of the erfindungsgemiissen self-lubricating anti-friction compositions are manufactured in the above-described procedure, which are angefi.ihrt in the table 1. In the table 1 also the Zusammensetzang of the well-known compositions is angefiihrt, those in the SU-PS No. 704,958 descriptive ist.

2 table I Lfd.

Nr.

Components composition composition mA. - % I II IlI IV V 3 4 5 6 7 1 2 3 4 6 7 8 9 11 12 Polyakaproamid casting PP Glasfasergefiilltes PP Mineral61:

- A - b --C Silikon61:

- D --e - f graphite of polyethylenes PolypropyIen inhibitor of the donor effect:

86 73 60 - - - - - 73 -…. 73 3 7 10 - - -- -- -- 7 - 7 I0 7 7 10 15 - - - - 10 - Tahelle 1 (continuation) current Komponentcn Nr.

13 - A 14 - B - C inhibitor of the acceptor effect:

16 - D 17 - E 18 - F 19 Polytetrafluor. ylen Athylendiaminotetraessigsfiure Kom posifionszusanmmnsetztmg mA. - % I 11 11I IV V' 1 3 5 - - - - - 3 - q 668,774 continuation of the table 1 current VI VII VIII Nr.

1 8 9 I0 IX X Nachder SU-PS No. 704,958 11 12 13 1 86 73 60 - - 73.4 2 - - - 73 - - 3…. 73 4…. = 12 7 3 7 10 - - - 8 - - - 7 - - 9 - - - 7 - I0 “5 7 10 7 7 - 11 - - - 10 10 - 12 5 10 15 - - - 13 ......

14 ......

16 1 3 5 - - - 17 - - - 3 - - 18…. being inferior to 3 19…. 14…. 0.6, in the table 2, are physikaliseh mechanical (zerst6rende Zugund compression stress), friction (coefficient of friction and VerschMssintensitfit) and anti-corrosion (rate of corrosion) - characteristics invention in accordance with issen composition (Zusamnaensetzungen I-VI) and the Konapositionen after the SU-PS No. 704,958 angeffihrt.

The physical-mechanical characteristics of the selbsts5 schnaierenden compositions became with Hflfe of a tension testing machine at a speed of the shift of the mobile grip arm yon 50 RAM/rain ermittelt.

the bush constituted 2.5 and/or 0.5 MPa. The Verschleissintensit it (J) according to the formula was erreehnet:

J = A___G__G. 10-8, 9 " A's where AG - Gewiehtsverschleiss, gnaw, p - sample density with 20 °C, g/cm3, A sample-flat, cm2, S - friction way, kna.

Friction attempts became on the friction machine 6o of Korrosionsversuche became after the Sehnellnaethode according to the pattern Weller Lagerschale>) durchgeffihrt. As if durchgeffihrt, by the polarization resistance Rn GegenkSrper using one a role out Kohlenstoffdes of two-electrode giver, that stole with the sample from too nait einena content of carbon yon 0.42-0.50 priifenden material kontakfiert, in an electrolyte mass.

MA. - %, a Hfirte HRC yon 40--45, a Ranheit RA yon thereby was used electrodes, those from Kohlenstoff0,8-1 n. The F the iehe Arbeitsoberfl iche of the bush, 65 stole with a content of carbon yon 0.09 to 0.15 from the selbstschemierenden Antifrikfionskonapositionen mA. - % manufactured sin& the Arbeitsfi ichen the electrodes are manufactured, resemble 2 cmz. The linear running speed warden up to the Ranheit RA = 0,4--0.5 GM polished, those in the friction zone 0.1 and 1.0 m/s, demand amounted to not working flat steel bar ichen warden dutch paraffin isoliert.

668,774 as electrolytes became 0.1 n-HCIund ln-Na2 SO4 - L6sung angewendet.

The Korrosionsgesehwindigkeit iB, g (m2 " h)] was calculated according to the formula:

iB_ 2KB S'Rn 'where KB - Gewiehtskoeffizient of the corrosion, yon that. Electrolyte concentration abhiingt, l - g/h (in the 0,1n-HCIL6sung is KB = 20.1 and in the ln-Na2 SO4 - L6sung is KB =0,032), Rn - polarization resistance, flat steel bar S - F1iiche of mutual Uberdeckung of electrodes m2.

(Zaschita metallow), No. 6, 1982, publishing house Nauka), Moscow: V.A. Goldade, Y.M. Zolotovitsky, A.S. Neverov, L.S. Pinehuk evaluation that protection particularly clinging yon inhibierten materials according to the polarization resistance method)), P. 946--949).

Table 2 Lfd.

No. Characteristic data composition compositions 1 2 3 4 6 7 8 2 Zerst6rende demand, MPa:

- with the course (cry) - with the pressure (dr) Zerst6rende Beanspruehung with course (az) sew 100 hours of the thermal oxidation at air with 150 °C, MPa coefficient of friction at steel without lubrication VersehMs sinten sit, it J x 108):

- P=2,5 MPa, V=0,1 m/s - P=0,5MPa, V=I, 0 m/s Korrosionsgesehwindigkeit 10-3 g (m2-h) of a steel electrode, which contacts with the sample of the too untersuehenden material:

- in 0,1n-HC1 - in ln-Na2 SO4 I 3 II III IV 4 5 6 50-68 45-60 38-52 6078 76-95 70-92 64-87 96-123 32--45 40-56 36--49 570.420.310.320.300.46 0.35 0.35 0.36 4.8 1.03 1.01 2.3,5.9,2.0,1.9,3.1 65-91 20-33 17-25 243, & 2.41.0 1.4,4.8,3.6,1.0 continuation animal table 2 current V VI VII Nr.

1 7 8 9 VIII IX X after the SU-PS 11 12 13 1 2 3 4 6 7 8 106-118 52-67 48-62 162-178 80-93 71-93 85-92 36--47 42-57 0.350.340.320.40 0.41 0.36 1.17 4.7,1.2,2.2,5.3,2.1 21-38 52-76 22-37 1.53.31.91.7 4.2,2.7 like it out 2 values angeffihrten in the table evidently, vergr6ssert is betrfichtlich the Einffihrung into the composition of the erfindungsgemiissen composition of a corrosion inhibitor the Wfirmestandfestigkeit, i.e. its Oxydationsbest ndigkeit. Thus crz the erfindungsge41-52 62-76 I05-120 65-80 100-119 168-180 79 37 sinks--46 56-70 78-89 26 0.290.310.350.37 0.37 0.36 0.37 1.08 2.24 1.05 3.5,1.7 3.12 2.09 3.8 16-20 21-42 25-37 120-150 0.8,1.6 1.560-87 1.9 m issen composition after 100 hours of thermal oxidation at air be/150 °C from 5 to 20%, wiihrend ffir the composition sew the SU-PS No. 704,958 around more than the H ilfte themselves reduced. The application of the Korrosionsinhibitots as a component of the erfindungsgemfissen composition makes it possible to lower the rate of corrosion of the metallic Gegenk6rpers on the 1/50 to 1/100. Also after the friction characteristic data the erfindungsgemiisse composition of the composition does not stand according to the SU-PS 704,958 nach.

Products, made of the erfindungsgemiissen composition, were geprtift at the units by motor vehicles, harvesting machines as well as Erd61und Erdgasausrfistungen. The test results witness yon to high effectiveness of the use of the given composition in the friction units instead of the anti-friction cast iron, the Babbite and babbitt metals on the basis yon copper, aluminum and Zink.

668,774 invention in accordance with isse self-lubricating anti-friction composition exhibits thus high physical-mechanical and anti-friction characteristics, erm6glicht it, to restrain and therefore s the corrosion-mechanical wear yon construction units decrease the intergranular corrosion at the friction units, increases the Konstantheff of physical-mechanical Eigenschaflen with erh6hten temperatures, is with the processing to products technologiegerecht.

The erfindungsgemiisse self-lubricating Antifriktionsl0 composition knows Krafffahrzeugen, harvesting machines, Erd61und Erdgasausrfistungen for production yon construction units of the friction units yon and in other fields of the technology their application finden.

C