Paper sizing agent

The invention relates to a reactive sizing agent comprising stabilizing the stable aqueous dispersion, method for preparing the same and its in the paper, paperboard, and cardboard the use of sizing.

Reactive sizing agent such as alkyl ketene dimer used for a large number of paper, paperboard, and cardboard sizing in the machine. The reactive sizing agent is usually regarded as commercially available dispersions. Its generally comprise cationic polymer such as cationic starch, or substantially given on the cellulose reactive sizing and/or as a protective colloid, synthetic cationic polymer.

In order to ensure that the sizing agent dispersion is suitable, they must have sufficient stable viscosity in order to make it keep the pumping and can be diluted in order to add to the paper making machine. In practice, in the dispersion is at most 40 the keep the low viscosity under [...] a few weeks. Because of the inherent instability of colloidal system, it is difficult to meet these requirements. Usually, a sharp increase in the viscosity of the dispersion until the dispersion can no longer be pumping or condensing. Dispersion the higher the content of the reactive sizing agent, the more obvious problems.

US-A-3,223,544 disclosed comprising cationic starch is used as a protective colloid, and anionic dispersing agent as a stabilizing agent, alkyl-ketene (AKD) dispersion.

WO-A-96/26318 disclosed comprising N-vinyl pyrrolidone and N-vinyl imidazole copolymer or polyethylenimine-based condensation products as protective colloid to AKD dispersion.

WO   2004/022847 discloses polyvinyl amines the AKD dispersion containing starch as a promoter used in the use of internal sizing.

WO-A-98/41565 discloses includes amino-containing polymer and the reaction product of a diketene of as the protective colloid AKD dispersion, wherein the amino-containing polymer is a polymer containing vinylamine units, and branched polyethylene imine grafted branched polymer with diketene and the weight ratio of the 10000 [...] the 1-1 [...] 3.

Prior German Patent application DE   102004010447.6 discloses polyvinyl amines in reactive sizing agent aqueous dispersions as in the use of a protective colloid. Dispersion preferably not containing cationic starch.

The purpose of this invention is to provide-based stabilizing the reactive sizing agent aqueous dispersion, wherein the paper sizing agent has good sizing effect and sufficient stable viscosity.

We have found that the object according to the present invention, through the stabilizing comprises the following components:

(A) a stable aqueous dispersion of the reactive sizing agent,

(B) based on reactive sizing agent, 5-100 weight %, preferably 10-100 weight %, especially 20-50 weight % having at least 5mmol/g substantially linear basic nitrogen atom of the nitrogen-containing polymer,

(C) based on reactive sizing agent, 1-50 weight %, preferably 3-25 weight %, especially 10-20 weight % substitution degree is at least 0.05, preferably 0.05-0.5, in particular 0.08-0.3, more preferably 0.1-0.2 cationic starch.

Usually, this invention paper sizing agent comprises on the basis of total weight of the paper sizing agent 1-15 weight % reactive sizing agent.

The term "stable dispersion" means a dispersion in the 40 the stored under [...] 4 week still more than maintain the fluid and does not condense.

"Linear polymer" should be understood as basic does not have the branching and cross-linked polymer. A polyalkyleneimine, in particular polyethylene imine because of its structure is azoly perssad branched not considered to be "linear polymer".

"Basic nitrogen atom" should be understood as in the aqueous solution by the Br can be Nsted acid protonated those nitrogen atom. Basic nitrogen atom, in particular primary amino, secondary amino groups and tertiary amino, wherein the preferred primary amino. In the nitrogenous polymer is protonated basic nitrogen atom preferably to at least 90mmol %, in particular basic quantitative. Protonated by the mineral acid such as hydrochloric acid, sulfuric acid or phosphoric acid to reaction, but is preferably carried out by reaction with a carboxylic acid. In particular, suitable carboxylic acid is formic acid, acetic acid, propionic acid, oxalic acid, tartaric acid, citric acid, and the like. If the nitrogen-containing polymer is less than the whole acid for 5 the pH, the basic quantitative of protonated.

According to the present invention comprising at least nitrogen-containing polymers for 3mmol/g, preferably at least 5mmol/g, particularly preferably 7.5-23mmol/g, most preferably 12-18mmol/g basic nitrogen atom. Basic nitrogen atom in the polymer content of ρ can be calculated according to the following formula:

ρ=x_N / (x_N M_N + x_o M_o)

Wherein x_N is provided with a basic nitrogen atom of a monomer (such as vinylamine) the mole fraction, x_o not to have nitrogen atom (alkaline) of a monomer (such as vinyl formamide) the mole fraction, M_N is provided with a basic nitrogen atom and the molecular weight of the monomer M_o not to have nitrogen atom (alkaline) the molecular weight of the monomer. The term "mole fraction" here means a polymer of the monomer.

Nitrogen-containing polymer having a weight average molecular weight of Mw for example, 500 to 1 million, preferably 750 to 5 million, particularly preferably 1000 to 2 million (determined by light scattering). The molar mass range is equivalent to, for example, K value is 30-150, preferably 60-90 (under H.Fikentscher, in 25 the [...] , pH to 7 and polymer concentration of 0.5 weight % lower, in the concentration of 5 weight % in the measured sodium chloride solution).

Suitable nitrogen-containing polymers include N-vinyl carboxamide and/or N-ethylene homopolymers and copolymers of imide [...] hydrolysis product. In the hydrolysis, acyl by acid, the role of alkali or enzyme from some or all of the polymeric N-ethylene carboxamide of base or N-ethylene [...] imide unit removing, forming vinylamine unit.

Suitable N-ethylene carboxamide of base in principle open chain and ring N-ethylene carboxamide of base. N-vinyl carbonsaureamide preferably of the open chain N-ethylene carboxamide of base, especially those whose hydrolyzed to obtain the primary amine of the open chain N-ethylene carboxamide of base. Particularly suitable N-ethylene carboxamide of base embodiment is N-vinyl formamide, N-vinyl-N-methyl formamide, N-vinyl acetamide, N-vinyl-N-methyl acetamide, N-vinyl-N-ethyl acetamide and N-vinyl propionamide, especially N-vinyl formamide. Suitable N-vinyl-imide embodiment is N-vinyl succinimide and N-vinyl phthalimide. The monomers can be used alone or with another or mixture of polymerized along with other monomers.

The polymer containing vinylamine units such as US-A-4,421,602, S-A-5,334,287, EP-A-0   216   387, US-A-5,981,689, WO-A-00/63295 and US-A-6,121,409 open.

N-vinyl carbonsaureamide and copolymerizing monoethylenically unsaturated monomer is copolymerized with the all of the compound. Examples of these compounds has 1-6 carbon atoms of the unsaturated carboxylic acid of the vinyl group formic acid acetate, vinyl acetate, vinyl propionate and butyrate acetate, and vinyl ether such as C₁-C₆ alkyl vinyl ether such as methyl vinyl ether or ethyl vinyl ether. Other suitable comonomers are ethylenically unsaturated C₃-C₆ carboxylic acid ester, amide and nitriles, such as methyl acrylate, methyl methacrylate, ethyl acrylate and ethyl methacrylate, acrylamide and methacrylamide and acrylonitrile and methacrylonitrile.

Other suitable carboxylic acid ester is derived from the in each case there is only one OH group esterified glycol or polyalkylene glycol, such as hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxide propyl acrylate, acrylic acid hydroxy Ding Zhi , methyl hydroxide propyl acrylate, methyl acrylate and hydroxy Ding Zhi for mole of quality 500-10000 polyalkylene glycol acrylic acid monoester.

Other suitable co-monomer is an ethylenically unsaturated carboxylic acid amide, such as acrylamide or methacrylamide and has 1-6 carbon atoms of the alkyl group of monoethylenically unsaturated carboxylic acids and N-alkyl mono amide such as diacid N-methyl acrylamide, N, N-dimethyl acrylamide, N-methyl methyl acrylamide, N-ethyl acrylamide, N-propyl acrylamide and tertiary-butyl acrylamide.

Other suitable comonomer is N-vinyl pyrrolidone, N-vinyl caprolactam, acrylonitrile, methacrylonitrile, N-vinyl imidazole and substituted N-vinyl imidazole such as N-vinyl-2-methyl imidazole, N-vinyl-4-methyl imidazole, N-vinyl-5-methyl-imidazole or N-vinyl-2-ethyl imidazole, and N-vinyl imidazoline such as N-vinyl imidazoline, N-vinyl-2-methyl-imidazoline and N-vinyl-2-ethyl imidazoline.

The copolymer preferably comprises at least 50 mole % of at least one polymerization unit forms incorporated N-ethylene carboxamide of base. Copolymerized monomer is preferably acid-free base.

In order to prepare suitable polyvinyl amines, preferably starting at N-vinyl formamide in the homopolymer or copolymer N-vinyl formamide, for example, with formic acid acetate, vinyl acetate, vinyl propionate, acrylonitrile, N-vinyl caprolactam, N- ethenyl urea , N-vinyl-pyrrolidone or C₁-C₆ a copolymer of alkyl vinyl ether, then its N-vinylformamide unit the hydrolisis becomes N-vinylamine unit, wherein the degree of hydrolysis of up to preferably 25-100 mol %, particularly preferably 50-100 mol %, and in particular preferably 70-100 mol %. The hydrolysis of the above-mentioned polymer by a known method, by acid, the role of alkali or enzyme. When using the acid as a hydrolytic agent, polymer of the vinylamine unit to ammonium salt form, the under the situation of hydrolysis with an alkali to form a free amino group.

Vinylamine polymer preferably in the form of a salt-free. Not containing the solution of salt may, for example, by means of the suitable for ultrafiltration on a film by the above-mentioned preparation of polymer solution containing salt, a suitable membrane such as blocking 1000-50000 Dalton, preferably 10000-300000 Dalton.

Preferably b alkenamine polymer is the degree of hydrolysis for 25-100 mol % of the amine homopolymer and degree of hydrolysis 25-100 mol % and in each case the K value is 30-150, especially 60-90 vinyl formamide with acetic acid acetate, vinyl alcohol, vinyl pyrrolidone or acrylamide copolymer.

As an alternative, comprises a pendant containing alkaline nitrogen atom of the polymerization of the monomer unit of the polymer or its and not (alkaline) nitrogen atom-containing monomer to be suitable for the copolymers can be used as the proportion of the nitrogen-containing polymer.

Suitable pendant groups with containing alkaline nitrogen atom of a monomer such as allylamine; alkaline acrylate such as acrylic dimethylamino ethyl acrylate, dimethylaminoethyl methacrylate, diethyl amino ethyl acrylate, diethyl amino ethyl methacrylate, acrylic acid dimethylamino propyl ester, dimethyl amino propyl methacrylate, acrylic acid diethylamino propyl ester, acrylic acid dimethylamino n-butyl and acrylic acid diethylamino n-butyl; alkaline (meth) acrylamide such as dimethyl amino ethyl acrylamide, dimethyl amino ethyl methyl acrylamide, diethyl amino ethyl acrylamide, diethyl amino ethyl methyl acrylamide, dimethyl amino propyl acrylamide, diethylamino propyl acrylamide, dimethyl amino propyl methyl acrylamide and diethyla amino propyl methyl acrylamide.

Suitable not (alkaline) nitrogen atom-containing monomer for the above-mentioned those.

The term "cationic starch" and "cationic modified starch" synonymous use here. Suitable cationic starch as a commercial. Initial starch can be any desired type of starch, such as potato starch, corn starch, wheat starch, waxy corn starch and cassava starch. Preferred branched starch content is more than 50 weight %, preferably 80-100 weight % of the starch, particularly preferably those branched starch content is at least 90 weight % of the starch.

Can be protonated or with cationic charge in the group such as dialkylamino or trioxane amino by means of chemical reaction with the starch some of the free hydroxyl. Suitable cationic reagent especially dialkylamino alkyl epoxides and dioxan amino alkyl halide. Alkyl outside in addition, cationic reagent can also include the aryl.

Preferred cationic reagent such as N, N-dimethylamino ethyl chloride, N, N-diethyl amino ethyl chloride, N, N-dimethylamino propyl chloride, 3-dibutylamino -1, 2-epoxypropane, 2-bromo-5-diethyla aminopentane hydrogen bromide , N-(2, 3-epoxy propyl) piperidine, chlorinated 2, 3-epoxy propyl trimethyl ammonium and N, N-(2, 3-epoxy propyl) methylaniline. Furthermore, free amine, can use the hydrochloric acid salt or other salt.

Initial starch and cationic reagent between the reaction preferably is carried out in an alkaline medium. Reagent for use depending on the desired proportion of the degree of substitution. The substitution degree is cationic group of the carbohydrate unit (i.e. glucose unit) ratio. It can be assumed that the maximum value of 3.

The invention paper sizing agent reactive sizing agent such as C₁₂-C₂₂ alkyl ketene dimer, C₅-C₂₂ alkyl succinic anhydride or C₅-C₂₂ alkenyl succinic anhydride, isocyanate C₁₂-C₃₆ alkyl ester and/or organic isocyanate such as isocyanic acid lauryl ester , eighteen alkyl isocyanate, alkyl isocyanate fourteen, sixteen alkyl esters of isocyanic acid, isocyanic acid twenty alkyl ester and isocyanic acid decyl. It is preferred to use a built-in sizing agent is alkyl ketene dimers and long-chain alkyl or alkenyl succinic anhydride.

Examples of alkyl ketene dimer to fourteen alkyl double-ketene, stearyl dihydrogenmethylenebisphosphonate ketene, laurel dihydrogenmethylenebisphosphonate ketene, palinitic dihydrogenmethylenebisphosphonate ketene, oil-based double-ketene, shan 萮 dihydrogenmethylenebisphosphonate ketene or mixtures thereof. With different alkyl groups such as alkyl diketene hard fatty group palinitic dihydrogenmethylenebisphosphonate ketene, shan 萮ji stearyl dihydrogenmethylenebisphosphonate ketene, shan 萮 -based oil-based double-ketene or palinitic base Shan 萮 dihydrogenmethylenebisphosphonate ketene is also suitable. It is preferred to use a stearine dihydrogenmethylenebisphosphonate ketene, palinitic dihydrogenmethylenebisphosphonate ketene, shan 萮 dihydrogenmethylenebisphosphonate ketene or shan 萮 dihydrogenmethylenebisphosphonate ketene and stearyl dihydrogenmethylenebisphosphonate ketene mixture. Suitable for use as active sizing agent substituted succinic anhydride such as decene yl succinic anhydride, is eighteen alkenyl succinic anhydride, succinic anhydride and is dodecylene base16 alkene yl succinic anhydride.

Aqueous dispersions of the present invention based on the total weight of the dispersion usually has 1-50 weight % reactive sizing agent. For example, the dispersion of C₁₂-C₂₂ alkyl diketene based on the content of the total weight of the dispersion of 1-50 weight %, preferably 5-35 weight %. When using C₅-C₂₂ alkyl or C₅-C₂₂ the chain alkenyl succinic anhydride, based on the content of the total weight of the dispersion, such as 1-25 weight %, preferably 2-10 weight %.

Reactive sizing agent in order to stabilize the dispersion in the aqueous phase, usually paper sizing agent of the present invention comprising an anionic dispersing agent. In the anionic dispersant to the content of the aqueous dispersions based on reactive sizing agent for example, 0.01-5 weight %, preferably 0.01-2.5% by weight, very particularly preferably 0.1-1 weight %.

Preferred condensation of anionic dispersing agent is selected from the following:

(A) a condensate of naphthalene sulfonic acid and formaldehyde,

(B) phenol, a condensate of phenol sulfonic acid and formaldehyde,

(C) naphthalene sulfonic acid, a condensate of formaldehyde and urea, and

(D) phenol, phenol sulfonic acid, a condensate of formaldehyde and urea.

Anionic dispersing agent can be in order to free acid, alkali metal salt or alkaline earth metal salt and/or ammonium salt form. Ammonium salts derived from ammonia and can be primary amines, secondary amines and tertiary amine, such as dimethylamine, trimethylamine, hexylamine, cyclohexylamine, bicyclic hexyl amine , ethanolamine, diethanolamine and triethanolamine ammonium salt is suitable. The above-mentioned condensate is known and available on the market. The preparation of condensation of the said component, also can use the corresponding alkali metal salt, alkaline earth metal salt or ammonium salt to replace the free acid. Suitable for condensation catalyst such as acid such as sulfuric acid, toluene-P-sulfonic acid and phosphoric acid. optimal naphthalene sulfonic acid or its alkali metal salt with formaldehyde to the 1 [...] 0.1-1 the [...] 2, usually the 1 [...] 0.5-1 the [...] 1 molar ratio of condensation. For the preparation of phenol, a condensate of phenol sulfonic acid and formaldehyde molar ratio of the same in the above-mentioned range, use of phenol and phenol sulfonic acid any desired mixture replaces the naphthalene sulfonic acid and formaldehyde condensation. In addition to phenol sulfonic acid outer, also can use the phenol sulfonic acid alkali metal salt, ammonium salt. If necessary, the above-mentioned starting material in addition can be carried out in the presence of urea condensation. Naphthalene sulfonic acid, for example, based on or on the basis of a mixture of phenol and phenol sulfonic acid, sulfonic acid or each mole of naphthalene per mole of phenol and phenol sulfonic acid in a mixture of 0.1-5 mole urea.

The molar mass such as condensation 800-100000, preferably 1000-30000, especially 4000-25000. The anionic dispersant is preferably used by, for example, lithium hydroxide, sodium hydroxide, potassium hydroxide or ammonia and salt obtained condensates. Salt such as pH 7-10.

Furthermore, lignin sulfonic acid and its alkali metal salt, alkaline earth metal salt or ammonium salt is suitable for being used as anionic dispersing agent.

Other suitable anionic dispersing agent is amphipathic copolymer of the following monomers:

(I) hydrophobic monoethylenically unsaturated monomer, and

(Ii) a hydrophilic monomer having an anionic group, such as monoethylenically unsaturated carboxylic acid, mono-ethylenically unsaturated sulfonic acid, single ethylenically unsaturated phosphonic acid or mixtures thereof.

Suitable hydrophobic monoethylenically unsaturated monomer:

(A) for example, have 2-150 carbon atom olefin, styrene, α-methyl styrene, ethyl styrene, 4-methylstyrene, acrylonitrile, methacrylonitrile, single ethylenically unsaturated C₃-C₅ carboxylic acid and monobasic alcohol, acrylic acid or methacrylic acid and C₁-C₂₄ alkylamine amide, with 2-24 carbon atom of a vinyl ester of a saturated monocarboxylic acid, maleic acid or fumaric acid and C₁-C₂₄ diesters of monohydric alcohol, with 3-24 carbon atoms of the alcohol vinyl the ether or states mixture of compounds.

Amphiphilic copolymer containing a polymerization unit incorporated as, for example, of the hydrophilic monomer having an anionic group of monoethylenically unsaturated C₃-C₁₀ carboxylic acid or its anhydride, 2-acrylamide-2-methyl propane sulfonic acid, vinyl sulfonic acid, styrene sulfonic acid, vinyl phosphonic acid, said monomer salt or mixtures thereof as the hydrophilic monomer (b).

Particularly preferred polymeric unit includes the following monomer incorporated and the molar mass Mw 1500-100000 amphiphilic copolymers as the sizing agent aqueous dispersion of the anionic dispersant:

(A) with 4-12 carbon atom of the α-olefin, styrene or mixtures thereof as the hydrophobic monomer, and

(B) maleic acid, acrylic acid, methacrylic acid, maleic acid and has 1-25 carbon atoms or monoester of alcohol alkoxylated product these mellow , maleic acid monoamide, said monomer salt or mixtures of these compounds as the hydrophilic monomer having an anionic group.

Maleic anhydride and preferably C₄-C₁₂ olefin, particularly preferred C₈ olefin such as 1-octene and diisobutylene copolymer is used as the anionic dispersing agent. Diisobutylene is very particularly preferred. Maleic anhydride with olefins such as the molar ratio of the 0.9 [...] the 1-3 [...] 1, preferably 0.95 the [...] 1-1.5: 1. These copolymer preferably in order to hydrolyzed form as the use of aqueous solution or dispersion, an acid anhydride group in order to open form and preferably some or all of the carboxyl group is neutralized and. The following alkali to be used for the and: an alkali metal base such as sodium hydroxide, potassium hydroxide, sodium carbonate or potassium carbonate, alkaline earth metal salt such as calcium hydroxide, calcium carbonate or magnesium hydroxide, ammonia, primary amine, secondary amine or tertiary amine such as triethylamine, triethanolamine, diethanolamine, and ethanolamine and morpholine.

If the free acid form of the water-soluble amphiphilic copolymer is not full, then their use in the form of a water soluble salt; for example, to use a corresponding alkali metal salt, alkaline earth metal salts and ammonium salt. Amphipathic copolymer molar mass of for example the Mw 800-250000, usually 1000-100000, preferably 3000-20000, especially 1500-10000. The acid value of the amphipathic copolymer is, for example, 50-500mgKOH/g polymer, preferably 150-300mgKOH/g polymer.

Aqueous dispersions of this invention can include other components, for example, the hydrophobic substance with cellulosic reaction, these substances are described, for example, will contribute to the improvement in stability and EP-A-437   764 and EP-A-658   228 in. Suitable for the material of the reaction with the cellulose such as a fatty acid, fatty amides and fatty ester, and wax. For examples of these substances, do not purport to limited to, stearic acid shan 萮zhi , myristic acid stearyl esters, stearic acid heteroploid lauryl ester , the inhibition of carbonate, ester carbonate, oil-based-N, N-di-stearyl yl carbamate, paraffin, oleic acid b glycerlol, oleic acid tri-glycerinate three sweet oil and stearic acid ester.

Furthermore, additional dispersion of this invention containing finely divided aqueous polymer dispersion, the polymer dispersions to be used for paper sizing agent. These polymer dispersed body for example publicizes in EP-B-0   051   144, EP-B-0   257   412, EP-B-0   276   770, EP-B-0   058   313 and EP-B-0   150   003 in. These as a paper sizing agent polymer disperses through the body may, for example, be 1 parts by weight of copolymer solution in aqueous solution in the presence of polymerization 1-32 parts by weight to obtain a mixture of the following monomers:

(A) styrene, acrylonitrile and/or methacrylonitrile,

(b) C₁-C₁₈ alcohol acrylate and/or methyl acrylate, and/or saturated C₂-C₄ carboxylic acid vinyl ester, if required and,

(C) other monoethylenically unsaturated copolymerizable monomer, such as WO-A-96/31650 and its reference the literature.

Suitable (a) group of monomer is styrene, acrylonitrile, methacrylonitrile or styrene and acrylonitrile or of a mixture of a mixture of styrene and methacrylonitrile. The C₁-C₁₈ alcohol acrylate and/or methyl acrylate, and/or saturated C₂-C₄ carboxylic acid vinyl the ester serves as (b) group of monomer. Preferably ding Zhiru of butyl acrylate and methacrylic acid isobutyl acrylate, n-butyl acrylate and methacrylic acid isobutyl acetate is used as the (b) group of monomer. (C) group of monomer such as butadiene, isoprene, single ethylenically unsaturated C₃-C₅ carboxylic acid, acrylamide-based methyl propane sulfonic acid, sodium vinyl sulfonate, vinyl imidazole, N-vinyl formamide, acrylamide, methacrylamide, N-vinyl imidazoline, and cationic polymer, such as dimethyl amino propyl methyl acrylamide or acrylic acid dimethylamino b ester armor chloride. Per part by weight of copolymer using 1-32 weight parts comprising the component (a) to (c) of the monomer mixture. Component (a) and (b) the monomer can be any desired proportion of copolymerized, for example, in the 0.1 [...] the 1-1 [...] 0.1 molar ratio of copolymerized. If needed, (c) plurality of monomer used for changing the performance of the copolymer. Preparation of these additional polymer dispersions WO-A-96/31650 details can be found in the literature and its reference.

If the polymer dispersion used in the present invention in the reactive sizing agent aqueous dispersion, preferably such polymer dispersions containing cationic polymer, such as dimethyl amino propyl methyl acrylamide and/or acrylic acid dimethylamino acetic ester with styrene, acrylonitrile, butadiene and/or acrylic ester combination of those.

When the use of such polymer dispersions, based on the content of the reactive sizing agent is usually 25-300 weight %, preferably 50-250 weight %, particularly preferred and 75-200 weight %.

Furthermore, the invention relates to a method for preparing novel reactive sizing agent aqueous dispersion method.

To prepare the sizing agent dispersion, reactive sizing agent will normally be heated to above its melting point and the temperature of the water under the action of shearing force in order to melt the emulsified. Chain alkenyl succinic anhydride can be liquid at room temperature have been emulsified. By adding the lipophilic substances, such as the fatty acid, wax, resin acid and resin, aliphatic amide or aliphatic ester, if needed, can reduce the melting point of the reactive sizing agent, so as to improve the stability of the dispersions obtained.

For example, cationic starch and taking first aqueous solution of the anionic dispersant, in any desired sequence and the sizing agent and nitrogen-containing polymer into, and the obtained mixture to disperse the step. For example, in the dispersion step the 20-100 [...] , preferably 40-90 the under [...]. Sizing agent is preferably added in the form of in order to melt. Also not yet proved first heating a nitrogen-containing polymer and is advantageous by adding anionic dispersant. In the dispersion step, those skilled in the art use known device such as a high-pressure homogenizer, colloid mill and ultrasonic-diffuser. The in each case the dispersions obtained under cooling.

The viscosity of the paper sizing of this invention for example the 20-1000mPa.s, preferably 100-500mPa. s (using the Brookfield viscometer at 22 the measured under [...]). Viscosity in the 40 the store under [...] 4 rose, preferably at most less than immediately after two times of the initial viscosity value. In the preparation of the dispersion, preferably pH 3-4. Generally sizing agent has an average particle size of 100-3000nm, preferably 250-2000nm the sizing agent aqueous dispersion.

As the inventive dispersions internal sizing agent used for producing paper, paperboard, and cardboard. Paper, paperboard and card Cartonboard normally through the cellulose fiber slurry draining and production. Suitable cellulose fiber is the commonly used in all types of cellulose fiber, for example, from wood pulp obtained cellulose fiber and all the fiber plant. Woodpulps includes, for example, groundwood pulp, thermal mechanical pulp (TMP), chemical thermomechanical pulp (CTMP), pressure groundwood pulp, semi-chemical pulp, high-yield pulp and disc mill mechanical pulp (RMP) and waste paper. Can be bleached or unbleached chemical pulp the form is also suitable. For example these chemical pulp kraft pulp, sulfite pulp and alkaline slurry. It is preferred to use a not-bleaching pulp, it is also referred to as the sulfate french thick liquid not bleached. The fiber can be used alone or used as a mixture.

Cellulose fibers for example the pH of the slurry is 4-8, preferably 6-8. In a papermaking machine, the paper pulp can be conducted in a batch or continuous draining.

In the draining and drying of paper pulp after the paper products, the resulting built-in sized paper products such as paper, paperboard and cardboard quantitative such as paper 20-400g/m², preferably 40-220g/m².

In addition preferably the pulp in the presence of the retention aid draining. In addition to anionic retention aid or non-ion retention aid outside, such as polyacrylamide, also preferably the cationic polymer is used as retention aid and filter aid. The result is the significantly improved the operational performance of the paper machine.

The cationic retention aid can be used for all commercial products for the same. These products such as a cationic polyacrylamide, poly diallyl dimethyl ammonium chloride, high molecular weight polyvinyl amines, K value of greater than 150 high molecular weight polyvinyl amines, polyethylene imines, molar mass greater than 50000 polyamine, if suitable for graft ethyleni of and cross-linked modified polyamine, polyether amide, polyvinyl imidazole, polyvinyl pyrrolidone, polyvinyl imidazoline, polyvinyl tetrahydropyran (pyrines), poly (dialkylamino alkyl vinyl ether), in protonated form or in quaternized form of poly ((meth) acrylic acid dialkylamino alkyl ester), and can be made of binary carboxylic acids such as adipic acid can be a branched, and polyalkylene polyamine under DE-B-24   34   816 and for polyethylene glycol graft ethyleni ether crossing linking dichlorohydrine the diethylentriamine-amine with epichlorohydrin or reaction to get branched water-soluble reducing compound, and acrylamide or methyl acrylamide and acrylic acid dialkylamino ethyl ester or dimethylaminoethyl methacrylate copolymer, such as acrylamide and hydrochloride form or chlorinated methane quaternized forms of acrylic acid copolymer of dialkylamino ethyl ester. For the so-called other suitable retention aid comprises a cationic polymer such as cationic starch and fine silica microsomal series, or containing cationic polymer such as cationic polyacrylamide and bentonite particle system.

The cationic polymer used as a retention aid Fikentscher   K value for example greater than 150 (the polymer concentration is 0.5 weight %, 25 the [...] temperature and pH to 7 the lower, the concentration is 5% sodium chloride aqueous solution, measuring). Their consumption based on dry cellulosic fiber is preferably 0.01-0.3 weight %.

If needed, before the sheet can be formed by adding other additive in paper pulp, for example by technical personnel in the field of those additive known literature. These compounding chemicals such as a fixative, reinforcing agent and defoaming agent.

Furthermore, the present invention relates to novel paper sizing agent as internal sizing agent in the production of paper, paperboard and the use of cardboard.

The invention also relates to this invention paper sizing agent in the production of paper, paperboard, cardboard and is used for packaging cardboard of the liquid as in the use of internal sizing agent.

On the following embodiment of the present invention rather than limiting of the present invention.

Unless the civilization display otherwise indicated, in the embodiment the percentages are weight percentages. Under H.Fikentscher, Cellulose-Chemie   13 ( 1932), section 58-64 page and 71-74 page, in the 25 [...] temperature and pH to 7 the lower, in 0.5 weight % in polymer concentration the concentration of 5% aqueous sodium chloride solution of K value is measured. Polymer dispersions of the dispersed particles of an average particle diameter at the same time through the use of small volume module LS   230 by Coulter furlong Huo Philippines -diffraction (Fraunhoferdiffraction) determining and through electronic microscropy determination. Using the Brookfield viscometer at 22 the measuring viscosity [...] temperature.

Embodiment

floats the ink time

floats the ink time (measured in minutes) in accordance with DIN   53   126 test ink 50% through the time required for the test paper.

Water absorption

According to DIN   53   132 through the paper sheet stored in the water 60 seconds and measuring. To g/m² said water absorbing capacity.

Edge penetration

Both sides of the sheet with adhesive tape covering, not to be striped. Then the cutting by the 25 × 75 mm   a test piece. These test piece is immersed in a 70 the the concentration of the [...] 30% of hydrogen peroxide bath or dip in the 25 [...] to the concentration of 3% in the young acid bath. soaks in the bathdoes the preview and in the test piece to determine the heavy edge permeability.

Polyvinyl amines 1

By hydrolysis of poly N-vinyl formamide cationic polymer obtained, K value is 50, the degree of hydrolysis to 95 mol %, that is to say, it comprises about 95 mole % vinylamine unit and about 5 mol % vinyl formamide unit of the polymer. Formic acid for adjusting the pH of a polymer to 3.7.

Polyvinyl amines 2

By hydrolysis of poly N-vinyl formamide cationic polymer obtained, K value is 45, the degree of hydrolysis to 95 mol %, that is to say, it comprises about 75 mole % vinylamine unit and about 25 mol % vinyl formamide unit of the polymer. Formic acid for adjusting the pH of a polymer to 3.7.

Embodiment 1

The 30 parts by weight concentration is 5% by weight of cationic starch solution (using N, N-dimethylamino ethyl chloride modified starch, DS   0.1) heating to the 95 [...] , stirring into 5.7 parts by weight concentration is 5 weight % of a naphthalenesulfonic acid/formaldehyde condensation product sodium salt solution, mixture with 19.3 weight water mixing, and then add 90 the under [...] 20 parts by weight of molten C₁₆-C₁₈ alkyl ketene dimer. In the 90 under the [...] 25 parts by weight concentration is 12% by weight of the polyvinyl amines 1 is added to the emulsion in the aqueous solution.

The mixture through a high-pressure homogenizer in 100 and 75 the double-channel under [...] (two   passes) homogenizing and ice for rapid cooling.

A viscosity of the dispersions obtained 80 MPa. s (the 22 [...]), and the average particle size of the 1.3  m. In 40 the store under [...] 4 weeks, a viscosity of dispersions of 120 MPa. s.

Embodiment 2

Repeat embodiment 1, but to initially in the cationic starch solution by adding a naphthalenesulfonic acid/formaldehyde condensation product sodium salt solution and then adding polyamine 1. Alkyl ketene dimer to melt into mixture.

Subsequently, the high-speed stirrer the emulsification uses and homogenizing such as described in the high-pressure homogenizer in the to.

The dispersions obtained viscosity is 100 MPa. s (the 22 [...]), and the average particle size of the 1.5  m. In 40 the store under [...] 4 weeks, a viscosity of dispersions of 180 MPa. s.

The proportional 3

Repeat embodiment 1, but initially the cationic starch solution to adding polyvinyl amines 1 and then adding naphthalenesulfonic acid/formaldehyde condensation product sodium salt solution. Alkyl ketene dimer to melt into mixture.

Subsequently, the high-speed stirrer the emulsification uses and homogenizing such as described in the high-pressure homogenizer in the to.

The dispersions obtained viscosity is 250 MPa. s (the 22 [...]), and the average particle size of the 2.5  m. In 40 the store under [...] 4 weeks, dispersion is condensed and has become solid.

Embodiment 4

Repeating example 1, but using 22 parts by weight concentration is 18% by weight of the polyvinyl amines 2 solution instead of polyvinyl amines 1 solution.

A viscosity of the dispersions obtained 150 MPa. s (the 22 [...]), and the average particle size of the 1.4  m. In 40 the store under [...] 4 weeks, a viscosity of 300 MPa. s.

The proportion 5

Repeat example 4, but in the homogenizing and after cooling by adding polyvinyl amines 2.

The dispersions obtained viscosity is 250 MPa. s (the 22 [...]), and the average particle size of the 2.8  m. In 40 the store under [...] 4 weeks, dispersion has become solid.

The proportion 6

The 50 parts by weight concentration is 5% by weight of cationic starch solution (DS   0.1) heating to the 95 [...] , stirring into 5.7 parts by weight concentration is 5 weight % of a naphthalenesulfonic acid/formaldehyde condensation product sodium salt solution, mixture with 24.3 weight water mixing, and then add 90 the under [...] 20 parts by weight of molten C₁₆-C₁₈ alkyl ketene dimer emulsified by high-speed stirrer.

The mixture through a high-pressure homogenizer in 100 and 75 the double-channel are under [...] ice and rapid cooling.

A viscosity of the dispersions obtained 50 MPa. s (the 22 [...]), and the average particle size of the 1.4  m. In 40 the store under [...] 4 weeks, a viscosity of 130 MPa. s.

The ratio 7

The 52.3 parts by weight softening water is heated to the 90 [...] , stirring into 5.7 parts by weight concentration is 5 weight % of a naphthalenesulfonic acid/formaldehyde condensation product sodium salt solution and then adding 22 parts by weight concentration is 18% by weight of the polyvinyl amines 2 solution. In the 90 is added to the mixture under [...] the 90 under [...] 20 parts by weight of molten C₁₆-C₁₈ alkyl ketene dimer emulsified by high-speed stirrer.

The mixture through a high-pressure homogenizer in 100 and 75 the double-channel are under [...] ice and rapid cooling.

The dispersions obtained viscosity is 40 MPa. s (the 22 [...]), and the average particle size of the 0.9  m. In 40 the store under [...] 4 weeks, a viscosity of 900 MPa. s.

The proportional 3 and 5 display if by adding a nitrogen-containing polymer (the proportion 3) is added after or during the dispersion step (the proportion 5) is not of the stable dispersion. The proportion 6 and 7 display does not include the nitrogen-containing polymer (the proportion 6) cationic starch or not (the proportion 7) dispersion of in 40 the store under [...] 4 week viscosity increase.

Application example

Application example 1

In each case based on the dry cellulosic fiber mixture, in table 1 by the above-mentioned dispersion reading , 20 weight % calcium carbonate, 0.6 weight % cationic corn starch and 0.04 weight % cationic polyacrylamide (Polymin KE2020) added as a retention aid pulp, the pulp consistency to 8 grams per litro and comprises fully bleached 70% pine sulfate pulp and 30% mixture of birch sulphate pulp, freeness value is 35° (Schopper-Riegler). The mixture shall be adjusted to pH 7. Then in Rapid-K The paper then obtained by processing mixture former is paper 80g/m² of a sheet. Furthermore, the paper sheet is the steam heating of the drying cylinder in the 90 under [...] dry until water content is 7%. Immediately after drying, the water absorbing capacity of determining the sheet. Furthermore, the paper sheet is in the 25 [...] and 50% relative humidity storage 24 hours. Then repeat the measurement. The results shown in table 1.

Table 1  

Application example 2

In each case based on the dry cellulosic fiber mixture, the table 2 by the above-mentioned dispersion reading , 0.6 weight % cationic corn starch and 0.04 weight % cationic polyacrylamide (Polymin KE2020) in the paper pulp is added as a retention aid, the pulp consistency to 8 grams per litro and comprises 100% waste paper. The mixture shall be adjusted to pH 7. Then in Rapid-K The mixture then is processed on the shaper of the paper sheets, the paper is obtained 100g/m² of a sheet. Furthermore, the paper sheet is the steam heating of the drying cylinder in the 90 under [...] dry until water content is 7%. Furthermore, the paper sheet is in the 25 [...] and 50% relative humidity storage 24 hours. Then repeat the measurement. The results shown in table 2.

Table 2  

Application example 3

In each case based on the dry cellulosic fiber mixture, the table 3 by the above-mentioned dispersion reading , 20 weight % calcium carbonate, 0.75 weight % cationic corn starch and 0.04 weight % cationic polyacrylamide (Polymin KE2020) in the paper pulp is added as a retention aid, the pulp consistency to 8 grams per litro and comprises fully bleached 70% pine sulfate pulp and 30% mixture of birch sulphate pulp, its freeness value is 35° (Schopper-Riegler). The mixture shall be adjusted to pH 7. Then in Rapid-K The mixture then is processed on the shaper of the paper sheets, the paper is obtained 150g/m² of a sheet. Furthermore, the paper sheet is the steam heating of the drying cylinder in the 90 under [...] dry until water content is 7%. Then both sides of the sheet with adhesive tape covering, not to be striped. Then cut from the sheet 25 × 75 mm a test piece. The test piece is immersed in a 70 the the concentration of the [...] 30% of in hydrogen peroxide bath. Determining permeability through the heavy edge. The results shown in table 3.

Table 3