DE2814287A1 - Detergent compsn. contg. N-vinyl! imidazole polymer - as discoloration-inhibiting additive - Google Patents

Abstract

Detergent compositions contain anionic and/or non-ionic surfactants, framework substances and other usual additives, with addn. of 0.1-10 wt.% water-soluble or -dispersible N-vinyl imidazole homo- or co-polymer. The polymer additive is more effective than polyvinyl pyrrolidone in preventing transfer of colour to white or light-coloured textiles during washing with coloureds, and can be used in detergents contg. anionic surfactants. Pref. content of N-vinyl imidazole polymer is 0.2-5 (0.5-4)wt.%. Polymerisation grade is 10-10000(20-5000).

Description

"Detergents with a content of discoloration-inhibiting additives The present invention is a detergent and cleaning agent, in addition to Surfactants, framework salts, lead compounds usually present in such agents and other accompanying substances contains a compound capable of dye transfer from colored textiles to white or light-colored textiles during a joint Counteracting washing. From DE-OS 22 32 353 such means are already known, wherein the dye transfer inhibiting agent is polyvinylpyrrolidone consists. However, these means have disadvantages that are once that the effect on a number of dyeings or textiles is very low and on the other hand, that the use of the inhibitor is limited to such detergents that do not contain anionic surfactants. However, anionic surfactants count because of them many advantages in terms of application technology to the most important or common ones Detergent ingredients.

The disadvantages indicated are eliminated by the present invention avoided. The invention relates to a washing and cleaning agent containing anionic and / or nonionic surfactants, builder substances and other common ones Detergent additives, characterized by an on the total balance of the means based content of 0.1 to 5 wt .-% of a water-soluble or dispersible Ilomo- or copolymers of N-Viny 1 imidazo ls.

The degree of polymerization of the polymers can be within wide limits are and is, for example, 10 to 10,000, but preferably 20 to 5000. Since the determination of the molecular weight and thus: the degree of polymerization is multiple is difficult, the specific viscosity is usually considered Measure for indicated the degree of polymerization. According to the invention, polymers and are well suited Copolymers with a 1% strength by weight aqueous solution at 20 ° C determined specific viscosity from 0.01 to 5 and in particular from 0.1 to 1. The production of the polymers, for which no protection is desired, can in a known manner by radical initiated take place in aqueous solution or in an organic solvent can be worked.

Except for the homopolymeric poly-N-vinylimidazole, which is very effective has shown, linear and crosslinked copolymers come into question. To form linear Compounds suitable for copolymers and having an olefinic double bond are: Hydrocarbons such as ethylene, propylene and styrene; Vinyl or allyl compounds, such as vinyl methyl ether, vinyl ethyl ether, allymethyl ether, allyl ethyl ether, vinyl acetate and propionate (which may be wholly or partially saponified after the copolymerization can be), allyl acetate, allyl alcohol, N-vinylpyrrolidone and N-vinyloxazolidone and derivatives of acrylic or methacrylic acid, z.fl. their methyl or ethyl esters, Amides and nitriles; Derivatives of olefinic dicarboxylic acids, such as the methyl and ethyl esters, Diamides and nitriles of maleic acid and fumaric acid. Particularly suitable copolymerizable ones Compounds are N-vinylpyrrolidone, N-vinyloxazolidone, vinyl acetate and (meth) -acrylamide. Several of the aforementioned copolymerizable compounds can also be used in one Copolymers have been used. Particularly suitable terpolymers are, for example, those of N-vinylimidazoles with N-vinyloxazoiidone and N-vinylpyrrolidone. In the copolymers the proportion of N-vinylimidazole should be at least 25 mol%, preferably at least 30 mol% and in particular at least 50 mol - t are In such copolymers, at theirs; Manufacture of both N-vinylimidazole and N-vinyloxazolidone is assumed, the molar proportion of N-vinylimidazole should be at least as large or greater than that of N-vinyl oxazolidone.

Examples of particularly suitable copolymers are accordingly those from N-vinylimidazole and N-vinylpyrrolidone in a molar ratio of 1: 2 to 100: 1 of the N-vinylimidazole and of N-vinyloxazolidone in a molar ratio of 1: 1 to 100: 1 and of the ternary Copolymers of N-vinylimidazole, N-vinyloxazolidone and N-vinylpyrrolidone in a molar ratio 1: 1: 1 to 100: 1: 1 or 100: 100: 1 or 100: 1: 100.

Finally, the copolymers can also be used with compounds with 2 or more copolymerizable double bonds. Because such copolymerizable compounds to three-dimensionally crosslinked polymers with high Viscosity and decreasing water solubility should lead to their proportion less than 10 mol%, preferably less than 5 mol%, based on the total amount of polymerizable Connections amount. Examples of suitable compounds are methylene-bis-acrylamide, Divinylbenzene, triallyl cyanurate and tetraallyloxyethane.

The content of the agents according to the invention in the omo- or

Copolymer of N-vinylimidazole is 0.1 to 10, preferably 0.2 to 5 and in particular 0.5 to 4% by weight.

In addition to the polymers mentioned, the agents according to the invention contain also anionic and / or nonionic surfactants and detergency enhancing agents or structural substances that bind alkaline earth ions. Suitable further ingredients are Washing alkalis, neutral salts, bleaching agents, anti-graying agents, optical ones Brighteners, enzymes and stabilizers as well as others, usually in detergents Auxiliaries and additives used.

Suitable anionic washing active substances are those from the sulfonate or sulfate type, for example alkylbenzenesulfonates, in particular n-dodecylbenzenesulfonate, also olefin sulfonates, d-sulfofetate, primary and secondary alkyl sulfates as well as the sulfates of ethoxylated or propoxylated higher molecular alcohols.

Other compounds of this mass, which may be in the detergents are the higher molecular weight sulfated partial ethers and partial esters of polyhydric alcohols, such as the alkali metal salts of the monoalkyl ethers or the monofatty acid esters of glycerol monosulfuric acid ester or

of 1,2-dioxypropanesulfonic acid. Sulphates also come from athoxylated ones or propoxylated fatty acid amides and AlkyS-phenols and fatty acid taurides and Fettäureisäthionate in question. Other suitable anionic kraschrohstoÎfe are Alkali soaps of fatty acids of natural or synthetic origin, e.g. Sodium soaps made from coconut, palm kernel or tallow fatty acids.

The anionic detergent raw materials can be in the form of sodium, potassium and ammonium salts and as salts of organic bases, such as mono-, di- or triethanolamine, are present. If the anionic and zwitterionic compounds mentioned have a have an aliphatic hydrocarbon radical, this should preferably be straight-chain and have 8 to 22 carbon atoms, In the compounds with an araliphatic Hydrogen radicals contain the preferably unbranched alkyl chains in a medium 6 to 15 carbon atoms.

As nonionic surface-active washing-active substances come in primarily polyglycol ether derivatives of alcohols, fatty acids and alkylphenols in question, the 3 to 30 glycol ether groups and 8 to 20 carbon atoms in the hydrocarbon radical contain. Polyglykolëtherderivate are particularly suitable in which the number of Ethylene glycol ether groups 5 to 15 and their hydrocarbon radicals of straight-chain, primary alcohols with 12 to 18 carbon atoms or of alkylphenols derive with a straight-chain alkyl chain having 6 to 14 carbon atoms.

Other suitable non-ionic washing raw materials are the water-soluble, Containing 20 to 250 ethylene glycol ether groups and 10 to 100 propylene glycol ether groups Polyethylene oxide adducts with polypropylene glycol, ethylenediaminopolypropylene glycol and alkyl polypropylene glycol having 1 to 10 carbon atoms in the alkyl chain. The compounds mentioned usually contain 1 per propylene glycol unit up to 5 ethylene glycol units.

Also non-ionic compounds of the amine oxide and sulfoxide type, which can optionally also be ethoxylated can be used.

Zwitterionic washing active substances can also be used, such as alkyl betaines and alkyl sulfobetaines, e.g.

of 3- (N, N-dimethyl-N-alkylammonium) -propane-1-sulfonate and 3 », N-dimethyl-N-alkylammonium) -2-hydroxypropane-1-sulfonate.

Phosphates, such as pentasodium triphosphate, can be used as builder substances and its mixtures with its hydrolysis products, d. H. Sodium pyro- and orthophosphates or the acidic and neutral detergents, which are particularly suitable for the production of liquid detergents Potassium pyrophosphates.

Other suitable framework substances are complexing aminopolycarboxylic acids. These include in particular the alkali salts of nitrilotriacetic acid and ethylenediaminotetraacetic acid. The salts of diethylenetriaminopentaacetic acid and the higher salts are also suitable Homologues of the aminopolycarboxylic acid mentioned. These homologues can for example by polymerizing an ester, amide or nitrile of t4-acetic acid aziridine and subsequent saponification to carboxylic acid salts or by reaction of polyethyleneimine made with chloroacetic acid or bromoacetic acid salts in an alkaline medium will. Other suitable aminopolycarboxylic acids are poly (N-succinic acid) ethyleneimine, Poly (N-tricarballylic acid) ethyleneimine and poly (N-butane-2,3,4-tricarboxylic acid) ethyleneimine, which are available analogously to the N-acetic acid derivatives.

Furthermore, complexing polyphosphonic acid salts can be present be, e.g. the alkali salts of aminopolyphosphonic acids, especially aminotri- (methylene-phosphonic acid), 1-hydroxyethane 1, 1 diphosphonic acid, ifethylene diphosphonic acid, ethylene diphosphonic acid and salts of the higher homologues of the polyphosphonic acids mentioned. Mixtures too the aforementioned complexing agents can be used.

Of particular importance are the nitrogen- and phosphorus-free, Polycarboxylic acids which form complex salts with calcium ions, including carboxyl groups containing polymers include. Citric acid, tartaric acid and benzene hexacarboxylic acid are suitable and tetrahydrofuran tetracarboxylic acid. Also containing carboxymethyl ether groups Polycarboxylic acids are useful, such as 2,2'-oxydisuccinic acid as well as with glycolic acid partially or completely etherified polyhydric alcohols or hydroxycarboxylic acids, for example triscarboxymethylglycerin, biscarboxymethylglyceric acid and carboxymethylated or oxidized polysaccharides. The polymeric carboxylic acids are also suitable with a molecular weight of at least 350 in the form of the water-soluble sodium or potassium salts, such as polyacrylic acid, polymethacrylic acid, poly-α-hydroxacrylic acid, Polymaleic acid, polyitaconic acid, polymesaconic acid, polybutenetricarboxylic acid as well the copolymers of the corresponding monomeric carboxylic acids with one another or with ethylenically unsaturated compounds such as ethylene, propylene, isobutylene, vinyl methyl ether or furan.

Complexing agents which are insoluble in water can also be used. These include phosphorylated cellulose and graft polymers of acrylic acid or methacrylic acid on cellulose, which can be in the form of woven or non-woven fabrics. Furthermore are spatially cross-linked and therefore water-insoluble copolymers of acrylic, Methacrylic, crotonic and maleic acid and other polymerizable polycarboxylic acids, possibly with other ethylenically unsaturated compounds in the form of Sodium or potassium salts suitable as sequestering agents. These insoluble Copolymers can be used as fleeces, sponges or in the form of finely ground, specifically lighter foams with an open-cell structure are present.

Alkali aluminum silicates are also suitable as water-insoluble builder substances and alkali borosilicates, which may contain bound water, and a calcium binding capacity have at least 50 mg CaO / g active substance. This includes connections in particular of the formula (Na2O) xAl2O3 (SiO2) @ where x is a number from 0.7 to 1.5 and y is a number from 1.3 to 4 mean. Also mixtures of the aforementioned water-soluble and water-insoluble ones Framework substances are useful.

The carbonates, bicarbonates, borates and are suitable as washing alkalis Silicates of sodium and potassium, in particular sodium carbonate and sodium silicates with a ratio of Na1O: SiO2 such as 1: 1 to 1: 3.5.

Oxygen-releasing bleaches are used as bleaching agents, such as alkali perborates, percarbonates, perpyrophosphates and persilicates as well as urea perhydrate in question, Sodium perborate is preferred in anhydrous form or as tetrahydrate used. To stabilize the per compounds, the agents can use magnesium silicate contain, for example in amounts of 3 to 20 wt .-%, based on the amount of Perborate. Agents to be used for washing textiles at temperatures below 70 ° C, so-called Ealtwaschmittel, bleach activators from the class of N or Contain O-acyl compounds with hydrogen peroxide in aqueous solution taking React formation of peracids.

Preferred bleach activators are tetraacetylmethylenediamine, the Tetraacetylethylenediamine and tetraacetylglycoluril. The ones from the bleach activator or powder particles consisting of the per compound can be coated with coating substances, like water-soluble polymers or fatty acids coated to interact to avoid between the per compound and the activator during storage.

Instead of the bleaching per compounds and their mixtures with bleach activators active chlorine-containing bleaches, for example sodium hypochlorite, Lithium hypochlorite, Na or K dichloroisocyanurate or trichloroisocyanuric acid or also mixtures of alkali persulphates and alkali chlorides, which are used under Formation of hypochlorite react, combined with the detergents according to the invention will.

This combination can already be done during the manufacture of the detergent or immediately before or during the application. To avoid -of The active chlorine compounds can also lose losses with inorganic or organic compounds Coating substances be coated or granulated.

The detergents can also contain optical brighteners, in particular Derivatives of diaminostilbndisulfonic acid or

their alkali metal salts. For example, salts of 4,4'-bis (-2 "-anilino-4" -morpholino-1,3,5-triazinyl-6 "-amino) -stilbene-2,2-disulfonic acid are suitable or similarly structured compounds which, instead of the morpholino group, have a Diethanolamino group, a methylamino group or a ß-methoxy-ethylamino group wear. Furthermore, brighteners of the diarylpyrazoline type are used as brighteners for polyamide fibers in question, for example 1 - (- p-sulfonamidophenyl) -3- (p-chlorophenyl) - # @ - pyrazoline as well as similarly structured compounds that instead of the sulfonaraido group a Carboxymethyl or acetylamino groups. Substituted ones can also be used Aminocoumarins, e.g. 4-methyl-7-dimethylamino- or 4-methyl-7-diethylaminocoumarin, The compounds 1- (2-benzimidazolyl) -2- (1-hydroxyethyl-2-benzimidazolyl) are also used as polyamide brighteners Ethylene and 1-ethyl-3-phenyl-7-diethylamino-catbostyril can be used. As a brightener for polyester and polyamide fibers the compounds are 2,5-di- (2-benzoxazolyl) -thiophene, 2- (2-benzoxazolyl) -naphtho- [2,3-b] -thiophene and 1,2-di- (5-methyl-2-benzoxazolyl) - suitable for ethylene. Furthermore, brighteners of the substituted diphenylstyrile type can be used to be present. Mixtures of the abovementioned brighteners can also be used.

Particularly suitable graying inhibitors are carboxymethyl cellulose, Methyl cellulose, as well as water-soluble polyesters and polyamides made from polyvalent ones Carboxylic acids and glycols or diaines, the free carboxyl groups capable of forming salts, Have betaine groups or sulfobetaine groups as well as colloidally soluble in water Polymers or copolymers of vinyl alcohol, vinyl pyrrolidone, acrylic amide and acrylic nitrile.

The agents can also include enzymes from the class of the proteases, lipases and amylases or mixtures thereof. Bacterial strains are particularly suitable or fungi such as Bacillus subtilis, Bacillus licheniformis and Streptomyces griseus obtained enzymatic active ingredients.

Neutral salts, especially sodium sulfate, are also used as well as biocides such as halogenated diphenylniethane, salicylanilide, garbanilide and Phenols into consideration. Liquid agents can also contain hydrotropes and solvents contain, such as alkali salts of benzene, toluene or xylene sulfonic acid, urea, Glycerine, polyglycerine, di- or triglycol, polyethylene glycol, ethanol, i-propanol and ethereal alcohols.

If necessary, known foam inhibitors, such as saturated Fatty acids and their alkali soaps with 20 to 24 carbon atoms, trialkyl melamines, hydrocarbons and silicones, present.

The quantitave Z @@ ammens @ t @ ung the inventive detergent can fluctuate within wide limits, preferably within the range (in percent by weight): 0.1-10%, preferably 0.2-5% polymer according to the invention 0.5-30%, preferably 1 - 20% soap and resp.

or sulfate or sulfonate tonside, 0.5-30%, preferably 1-20 % nonionic surfactant, 0 - 60%, preferably 5 - 50% phosphorus-free builder substances, 0 - 60%, preferably 10 - 50% phosphorus-containing structural substance, 0 - 25% washing alkalis, 0-30%, preferably 10-25%, of oxygen-releasing bleaches, in particular Na perborate and its combination with bleach activators and stabilizers, 0 - 3%, preferably 0.5-2%, of anti-graying substances, 0-1% optical Brighteners, dyes and fragrances, as well as antimicrobial substances, 0 - 3%, preferably 0.2 - 2% foam inhibitors.

EXAMPLE A. Preparation of the Polymers 1. For the preparation of poly-N-vinylimidazole, 78 g of N-vinylimidazole, 78 g of water and 2 g of Azoisobuttexsäuxedinitril added. The reaction mixture is stirred under a nitrogen atmosphere for 6 hours at 80 ° C, the viscosity of the Solution increases sharply.

The polymer is then made by concentrating the reaction mixture isolated to dryness and purified by reprecipitation from methanol / ether, after which Filter off, it is dried in a vacuum oven at room temperature. The one on one The specific viscosity determined by 1% strength aqueous solution was 0.30.

2. For the production of an N-vinylimidazole-N-vinyloxazolidone copolymer (Molar ratio 1: 0.85) are in 120 g of methanol, which by boiling for one hour has been freed of oxygen under a nitrogen atmosphere, 15 g of N-vinyl oxazolidone, 15 g of N-Vihylimidazol and 0.6 g of azoisobutterw säuredinitril dissolved and the solution Heated to boiling for 6 hours while stirring and bubbling with nitrogen. After cooling down the polymer is precipitated by pouring the reaction mixture into approx. 4 liters of ether, filtered off and dried in a vacuum cabinet at 50 ° C., spec, viscosity: 0.30.

3. As described in Example 2, using 19 g N-vinylimidazole and 5.6 g of N vinyloxazolidone a copolymer (molar ratio 4: 1 ) with a specific viscosity of 0.3.

4. An N-vinylimidazole-N-vinyloxazolidone copolymer was produced analogously to Example 3 synthesized with a molar ratio of 8: 1 and a specific viscosity of 0.14.

5. For the purpose of producing an N-vinylimidazole-N-vinylpyrrolidone copolymer (Molar ratio 2: 1) are 18.8 g of N-vinylimidazole in the manner indicated in Example 2 and 11.1 g of N-vinylpyrrolidone in the presence of 0.6 g of azoisobutyric acid dinitrile in Polymerized 120 g of methanol and isolated the copolymer by precipitation. Spec. Viscosity: 0.28.

6. As described in Example 5 using 9.4 g N-vinylimidazole and 22.2 g of N-vinylpyrrolidone a copolymer (molar ratio 2: 1) with a specific viscosity of 0.27.

7. An N-vinylimidazole-N-vinyloxazolic10n-N-vinylpyrrolidone copolymer was made from 10 g of N-vinylimidazole, 10 g of N-vinyloxazolidone and 10 g of N-vinylpyrrolidone (Molar ratio 1.2: 1: 1) in the presence of 1% azoisobutyric acid dinitrile in methanol obtain. Polymerization and work-up were carried out as in Example 2. Specific viscosity: 0.40.

8. The production of a poly (N-vinylimidazole-co-vinyl acetate) is successful in a 500 ml flask using 126 g toluene, 37.6 g N-vinylimidazole, 17.2 g vinyl acetate and 0.54 g azoisobutyric acid dinitrile. Under a nitrogen atmosphere the reaction mixture is then stirred for G hours at 80 ° C., the resulting Polymcre fails.

After cooling, the substance is filtered off and dissolved by dissolving in a mixture of methanol and water and subsequent precipitation by pouring this solution purified in acetone. The polymer is filtered off and placed in a vacuum cabinet dried at 50 ° C. Specific viscosity: 0.26.

9. For the production of poly (N-vinylimidazole-co-acrylamide) are in a 1 liter flask 706 g of water, 141 g of N-vinylimidazole, 35.5 g of acrylamide and 1.8 g of azolesobutyric acid dinitrile. Under a nitrogen atmosphere this will be The reaction mixture was stirred at 80 ° C. for 8 hours, the viscosity of the solution being high increases. After cooling, it is diluted with methanol and the polymer by pouring the solution in acetone precipitated. For cleaning it is in a mixture of methanol and water dissolved and reprecipitated by pouring into acetone; afterward the copolymer is separated off and dried in a vacuum oven at 50 ° C, spec. Viscosity: 0.93.

B. Washing tests Textile samples made of cotton were made with the following dyes colored.

a) Cibacron brilliant orange 2GZ b) Naphthol AS-OL Variamin blue salt B c) Sirius light scarlet BN d) Inuanthrene brilliant green GG e) Sirius light blue BL These dyed textile samples were used along with various ones below listed colorless test fabrics washed in the launderometer.

I) cotton II) refined cotton (wush and we @ r equipment) III) Mixture of polyester and refined cotton (1: 1) IV) Polyester fabric V) Polyurethane fabric (Lycra #) The weight ratio of dyed cotton fabric to white test fabric was 2: 1. There L. <j- 'were 7.5 g / l of a detergent the following composition used (in% by weight) 4.0% polymer According to the invention 8.5% Na-n-dodecylbenzenesulfonate 2.5% tallow alcohol, ethoxylated 14 times 1.5 t tallow alcohol, 5 times ethoxylated 3.5% Na soap (tallow fatty acid to coconut fatty acid 9: 1) 40.0% sodium tripolyphosphate 5.5% sodium silicate (Na20: SiO2 = 1: 3.3) 1.5% magnesium silicate 0.5% Na ethylenediaminetetraacetate 1.5 t Na carboxymethyl cellulose 20.0% sodium perborate, 0.3% optical brighteners and fragrances, the remainder sodium sulfate When using the cotton test fabric (I), the liquor ratio was (textile weight in g to wash liquor in ml) 1:12 and the washing temperature 90 ° C. The remaining test tissues were washed at a liquor ratio of 1:30 and a temperature of 60 ° C, wherein after the washing liquor has been heated to the specified temperatures, a washing time of 15 minutes each time. After washing was 3 times with tap water rinsed. The water hardness was 160 d.

First, the tests were carried out in the absence of the invention using polymeric discoloration inhibitors carried out and the occurred Color transfer measured photometrically.

The experiment was then repeated in the presence of the polymer and again the remission of the test tissue photometrically certainly. The difference AR of the two reflectance values is a measure of the "discoloration inhibition", i.e. the protective effect of the polymer in question. All in the following table The difference values listed are mean values from 5 parallel tests. the The results are compiled in the following table. The designations aI) bII) bIII) etc. stand for the combinations of dye a) with textile material I), dye b) with textile material II, dye b) with textile material III) etc. The "Elrepho" device from Carl Zeiss in Used in combination with the following filters.

Dye a) Filter 46/5 nb) "40/9" c) "46/5 nd)" 46/2 ne) "40/9 The results show that the polymers used according to the invention are suitable for measurably reducing color transfer. Bei- Polymeres Spec. Vis- aI bII bIII cIII dIV bV eV game kosity 1 poly-N-vinylimidazole 0.40 15 2 4 8 9-16 2 poly (N-vinylimidazole- 0.30 21 4 6 6 10-16 co-N-vinyloxazolidone) Mole ratio 1: 0.85 3 poly (N-vinylimidazole- 0.14 12 2 3 13 10 1 19 co-N-vinyloxazolidone) Mole ratio 4: 1 4 poly (N-vinylimidazole- 0.19 13 3 3 13 8-20 co-N-vinyloxazolidone) Mole ratio 8: 1 5 poly (N-vinylimidazole- 0.28 21 3 5 7 10-14 co-N-vinylpyrrolidone) Mole ratio 2: 1 6 poly (N-vinylimidazole-0.27 14 3 1 7 10 2 16 co-N-vinylpyrrolidone) Mole ratio 1: 2 7 poly (N-vinylimidazole- 0.40 19 4 5 7 9-19 co-N-vinyloxazolidone-co- N-vinylpyrrolidone) Mole ratio 1.2: 1: 1 8 poly (N-vinylimidazole-0.26 13 3 2 8 10-14 co-vinyl acetate) Mole ratio 2: 1 9 poly (N-vinylimidazole-0.98 13 1 2 8 11 6 15 co-acrylamide) Mole ratio 3: 1

Claims (12)

"Detergents with a content of discoloration-inhibiting additives" P a t e n t a n s p r ü c h e 1. Detergents and cleaning agents, containing anionic and / or nonionic surfactants, builders and other common detergent additives, characterized by a content based on the total weight of the agents 0.1 to 10 wt .-% of a water-soluble or dispersible homo- or Copolymers of N-vinylimidazole. 2. Means according to claim 1, characterized in that the degree of polymerization of the homo- or copolymer contained therein 10 to 10,000, preferably 20 to 5000 amounts to. 3. Means according to claim 1 and 2, characterized by a content of homopolymeric N-vinylimidazole. 4. Means according to claim i and 2, characterized in that the therein Polymers contained from a copolymer of N-vinylimidazole with an olefinic Double bond having copolymerizable compound exists. 5. Means according to claim 1, 2 and 4, characterized in that the polymers contained therein a copolymer of N-vinylimidazole with a copolymerizable one Olefin, vinyl, allyl, acrylic or methacrylic compound. 6. means according to search 4 and 5, characterized in that the proportion of the N-vinylimidazole on the copolymer is at least 25 moles. 7. Means according to claim 4 and 5, characterized in that the proportion of the N-vinylin dazene on the copolymer is at least 50 mol%. 8. Composition according to claim 4 to 7, characterized in that the copolymerizable Compound consists of N-vinylpyrrolidone and / or N-vinyloxazolidone, the molar The proportion of N-vinylimidazole is at least as large or greater than that of N-vinyloxazolidone. 9. Composition according to claim 4 to 7, characterized in that the copolymerizable Compound consists of vinyl acetate. 10. Means according to claim 4 to 7, characterized in that the copolymerizable compound consists of acrylamide and / or methacrylamide. 11. Means according to claim 4 to 10, characterized in that the copolymerizable compound up to 5 mol% of a compound with at least 2 copolymerizable double bonds exist. 12. Means according to claim 1 to 11, characterized in that its Content of homopolymers or copolymers of N-vinylimidazole 0.2 to 5, in particular 0.5 to 4% by weight