EP0291808B1 - Use of water soluble copolymerisates, wherein monomers having at least two ethylenically unsaturated monomers are taking part in wasking and cleaning agents - Google Patents

Abstract

The copolymers which contain a) 99.5 to 15 mol% of at least one monoethylenically unsaturated C3- to C6-monocarboxylic acid, b) 0.5 to 20 mol% of at least one comonomer which has at least 2 ethylenically unsaturated, non-conjugated double bonds and which has at least one -CO-OX group in which X is a hydrogen, an alkali metal or an alkaline earth metal equivalent or an ammonium group, c) 0 to 84.5 mol% of at least one monoethylenically unsaturated C4- to C6-dicarboxylic acid, d) 0 to 20 mol% of one or more hydroxyalkyl esters of monoethylenically unsaturated C3- to C6-carboxylic acids and e) 0 to 30 mol% of other water-soluble, monoethylenically unsaturated monomers which are copolymerisable with a) to d), with the proviso that the total of mol% data for a) to e) is always 100, and which have a K value by the Fikentscher method of 8 to 120, are used as additives to detergents and cleaners.

Description

In laundry detergents and cleaning agents, as is well-known, builders (builder) are required as ingredients in addition to surface-active substances. The builders have a variety of tasks in detergent and cleaning agent formulations, e.g. should they support the surfactants in the detachment of dirt, render the hardness formers of the water harmless, be it by sequestering the alkaline earth metal ions or by dispersing the hardness formers precipitated out of the water, promote the dispersion and stabilization of the dirt that is colloidally distributed in the wash liquor and to keep the optimal pH Value as a buffer during washing. With solid detergent and cleaning agent formulations, the builders should make a positive contribution to a good powder structure or flowability. Phosphate-based builders largely perform the tasks described above that are placed on a builder. For a long time, pentasodium triphosphate was indisputably the most important builder in detergents and cleaning agents. However, the phosphates contained in detergents reach the wastewater practically unchanged. As the phosphates are a good nutrient for aquatic plants and algae, they are responsible for the eutrophication of lakes and slow-flowing waters. In sewage treatment plants that do not have a so-called third purification stage, in which the phosphates are specially precipitated, they are not sufficiently removed. It was therefore early on to look for substances that could replace phosphates in detergents as builders.

In the meantime, water-soluble ion exchangers based on zeolites have found their way into phosphate-free or low-phosphate detergents. However, due to their specific properties, the zeolites cannot replace the phosphates as builders alone. The action of the zeolites is supported by other detergent additives which are compounds containing carboxyl groups, such as citric acid, tartaric acid, nitrilotriacetic acid and, above all, polymeric compounds containing carboxyl groups or their salts. Among the last-mentioned compounds, the homopolymers of acrylic acid and the copolymers of acrylic acid and maleic acid are particularly important as detergent additives, cf. U.S. Patent 3,308,067 and EP Patent 25,551.

The polymers mentioned are ecologically harmless because they are adsorbed on the activated sludge in the sewage treatment plants and are thus removed from the water cycle. However, these polymers are not sufficiently biodegradable in the sense of today's requirements for the wastewater constituents.

The object of the present invention is to provide additives for detergents and cleaning agents based on polymers which have a far better biodegradability than the polymers previously used for them.

• a) 99,5 bis 15 Mol.% wenigstens einer monoethylenisch ungesättigten C₃- bis C_e-Monocarbonsäure,
• b) 0,5 bis 20 Mol.% wenigstens eines mindestens 2 ethylenisch ungesättigte, nicht konjugierte Doppelbindungen aufweisenden Comonomers, das mindestens eine -CO-OX -Gruppe hat, in der X ein Wasserstoff-, Alkalimetall- oder Erdalkalimetalläquivalent oder eine Ammoniumgruppe bedeutet,
• c) 0 bis 84,5 Mol.% wenigstens einer monoethylenisch ungesättigten C₄-bis C_e-Dicarbonsäure,
• d) 0 bis 20 Mol.% eines oder mehrerer Hydroxyalkylester mit 2 bis 6 C-Atomen in der Hydroxyalkylgruppe von monoethylenisch ungesättigten C₃- bis C_B-Carbonsäuren und
• e) 0 bis 30 Mol.% andere, mit a), b), c) und d) copolymerisierbare, wasserlösliche, monoethylenisch ungesättigte Monomere mit der Maßgabe einpolymerisiert enthalten, daß die Summe der Angaben in Mol.% a) bis e) immer 100 beträgt und die einen K-Wert von 8 bis 120 (bestimmt am Na-Salz der Copolymerisate nach H. Fikentscher in wäßriger Lösung bei 25°C, einem pH-Wert von 7 und einer Polymerkonzentration des Na-Salzes von 1 Gew.%) haben, als Zusatz zu Wasch- und Reinigungsmitteln.

The object is achieved according to the invention by using water-soluble copolymers which

• a) 99.5 to 15 mol% of at least one monoethylenically unsaturated C ₃ to C _e monocarboxylic acid,
• b) 0.5 to 20 mol% of at least one comonomer having at least 2 ethylenically unsaturated, non-conjugated double bonds and having at least one -CO-OX group in which X is a hydrogen, alkali metal or alkaline earth metal equivalent or an ammonium group,
• c) 0 to 84.5 mol% of at least one monoethylenically unsaturated C _{4 to} C _e dicarboxylic acid,
• d) 0 to 20 mol.% of one or more hydroxyalkyl esters with 2 to 6 carbon atoms in the hydroxyalkyl group of monoethylenically unsaturated C ₃ to C _B carboxylic acids and
• e) 0 to 30 mol.% of other water-soluble, monoethylenically unsaturated monomers copolymerizable with a), b), c) and d) with the proviso that the sum of the data in mol.% a) to e) always 100 and which has a K value of 8 to 120 (determined on the Na salt of the copolymers according to H. Fikentscher in aqueous solution at 25 ° C., a pH of 7 and a polymer concentration of the Na salt of 1% by weight ) as an additive to detergents and cleaning agents.

The copolymers described above act as builders in detergents and cleaning agents and thus contribute to a washing activation of surfactants in the detergents and cleaning agents, a reduction in the incrustation on the washed textile and to a dirt dispersion in the washing liquor. However, these copolymers are surprisingly biodegradable and, in some cases, even more effective than the polymers previously used in detergents.

• a) 99,5 bis 15 Mol.% wenigstens einer monoethylenisch ungesättigten C₃- bis C₈-Monocarbonsäure,
• b) 0,5 bis 20 Mol.% wenigstens eines mindestens 2 ethylenisch ungesättigte, nicht konjugierte Doppelbindungen aufweisenden Comonomers, das mindestens eine -CO-OX -Gruppe hat, in der X ein Wasserstoff-, ein Alkalimetall- oder Erdalkalimetalläquivalent oder eine Ammoniumgruppe bedeutet,
• c) 0 bis 84,5 Mol.% wenigstens einer monoethylenisch ungesättigten C₄-bis Ce-Dicarbonsäure,
• d) 0 bis 20 Mol.% eines oder mehrerer Hydroxyalkylester mit 2 bis 6 C-Atomen in der Hydroxyalkyl- gruppe von monoethylenisch ungesättigten C₃- bis C_e-Carbonsäuren und
• e) 0 bis 30 Mol.% anderen, mit a) bis d) copolymerisierbaren, wasserlöslichen, monoethylenisch ungesättigten Monomeren.

The water-soluble copolymers are prepared by copolymerizing monomer mixtures

• a) 99.5 to 15 mol% of at least one monoethylenically unsaturated C ₃ to C ₈ monocarboxylic acid,
• b) 0.5 to 20 mol% of at least one comonomer having at least 2 ethylenically unsaturated, non-conjugated double bonds and having at least one -CO-OX group in which X is a hydrogen, an alkali metal or alkaline earth metal equivalent or an ammonium group ,
• c) 0 to 84.5 mol% of at least one monoethylenically unsaturated C _{4 to} Ce dicarboxylic acid,
• d) 0 to 20 mol.% of one or more hydroxyalkyl esters with 2 to 6 C atoms in the hydroxyalkyl group of monoethylenically unsaturated C ₃ to C _e carboxylic acids and
• e) 0 to 30 mol.% of other water-soluble, monoethylenically unsaturated monomers copolymerizable with a) to d).

The sum of the data in mol.% A) to e) is always 100.

As component a) of the water-soluble copolymers, monoethylenically unsaturated C ₃ to C _e monocarboxylic acids come into consideration. Suitable carboxylic acids of this type are, for example, acrylic acid, methacrylic acid, ethacrylic acid, vinyl acetic acid, allylacetic acid and crotonic acid. Acrylic acid and / or methacrylic acid is preferably used as the monomer of component a). The monomers of component a) make up 99.5 to 15 mol% of the copolymers.

The monomers of component b) are an essential component of the copolymers. These are comonomers which have at least two ethylenically unsaturated, non-conjugated double bonds and at least one -CO-OH group and / or their salt with an alkali metal, ammonium or alkaline earth metal base. These comonomers generally bring about an increase in the molecular weight of the copolymers and make up 0.5 to 20, preferably 1 to 12, mol% of the copolymers.

The comonomers b) can be obtained by reacting

b1) maleic anhydride, itaconic anhydride, citraconic anhydride or their mixtures with b2) polyhydric alcohols containing 2 to 6 carbon atoms, water-soluble or water-insoluble polyalkylene glycols of a molecular weight of up to 400, water-soluble polyalkylene glycols of a molecular weight of more than 400 to 10,000, polyglycerols, polyamines of a molecular weight Polyalkylene polyamines, polyethyleneimines, amino alcohols, hydroxyamino or diaminocarboxylic acids, such as in particular lysine and serine, copolymers of alkylene oxide and carbon dioxide, polyvinyl alcohol with a molecular weight of up to 10,000, allyl alcohol, allylamine, hydroxyalkyl esters with 2 to 6 carbon atoms in the hydroxyalkyl unsaturated group of mono C ₃ - to C _e -carboxylic acids or of saturated C ₃ - to C ₈ -hydroxycarboxylic acids or mixtures thereof.

Polyhydric alcohols containing 2 to 6 carbon atoms are, for example, glycol, glycerol, pentaerythritol and monosaccharides, such as glucose, mannose, galactose, uronic acids, such as galacturonic acid, and sugar acids, such as mucic acid or galactonic acid.

Water-soluble polyalkylene glycols are to be understood as meaning the addition products of ethylene oxide, propylene oxide, n-butylene oxide and isobutylene oxide or their mixtures with polyhydric alcohols having 2 to 6 carbon atoms, e.g. the adducts of ethylene oxide with glycol, adducts of ethylene oxide with glycerol, adducts of ethylene oxide with pentaerythritol, sorbitol, adducts of ethylene oxide with monosaccharides, and also adducts of mixtures of the alkylene oxides mentioned with polyhydric alcohols. These addition products can be block copolymers of ethylene oxide and propylene oxide, of ethylene oxide and butylene oxides or of ethylene oxide, propylene oxide and butylene oxides. In addition to the block copolymers, addition products are also suitable which contain the alkylene oxides mentioned in copolymerized form in a random distribution. The molecular weight of the polyalkylene glycols is advantageously up to 5,000, preferably up to 2,000. Of the water-soluble polyalkylene glycols, preference is given to using diethylene glycol, triethylene glycol, tetraethylene glycol and polyethylene glycol with a molecular weight of up to 1,500.

Also possible as component b2) are polyglycerols with a molecular weight of up to 2,000. Of this class of substances, preference is given to using diglycerin, triglycerin and tetraglycerin.

Suitable polyamines are, for example, preferably diamines, such as ethylenediamine, 1,3-propylenediamine, 1,4-butylenediamine and 1,6-hexamethylenediamine and melamine. Examples of suitable polyalkylene polyamines are diethylene triamine, triethylene tetramine, pentaethylene hexamine, N- (3-aminopropyl) -1,3-propidiamine and 3- (2-aminoethyl) aminopropylamine. Particularly suitable polyethyleneimines have a molecular weight of up to 5,000.

Amino alcohols, such as ethanolamine, 2-aminopropanol-1, neopentanolamine and 1-methylamino-2-propanol, are also suitable as component b2).

Also suitable as component b2) are copolymers of ethylene oxide and carbon dioxide, which can be obtained by copolymerizing ethylene oxide and carbon dioxide. Also suitable are polyvinyl alcohols with a molecular weight of up to 10,000, preferably polyvinyl alcohols with a molecular weight of up to 2,000. The polyvinyl alcohols which are produced by hydrolysis from polyvinyl acetate can be wholly or partly hydrolyzed. Other suitable compounds of component b2) are lysine, serine, allyl alcohol, allylamine and hydroxyalkyl esters with 2 to 6 carbon atoms in the hydroxyalkyl group from monoethylenically unsaturated C ₃ to Ce mono- and dicarboxylic acids.

The hydroxyalkyl ester groups of the last-mentioned monomers are derived from polyhydric alcohols, for example glycol, glycerol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 2,3-butanediol, mixtures of the Butanediols or propanediols, 1,6-hexanediol and neopentyl glycol. The polyhydric alcohols are esterified with monoethylenically unsaturated C ₃ to C ₆ carboxylic acids. These are the carboxylic acids mentioned above under a) and c). Suitable components b2) are thus, for example, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxy-n-propyl methacrylate, hydroxy-n-propylacrylate, hydroxyisopropyl acrylate, hydroxyisopropyl methacrylate, hydroxy-n-butyl acrylate, hydroxyisobutylacrylate, hydroxy-n-butyl methobutylethyl acrylate, hydroxyl nyl butyl methacrylate, hydroxyl Hydroxypropyldimaleinate, hydroxy-n-butylmonomaleinate, hydroxy-n-butyldimaleinate and hydroxyethylmonoitaconate. Of the hydroxyalkyl esters of the monoethylenically unsaturated dicarboxylic acids, both the mono- and the diesters of the dicarboxylic acids with the polyhydric alcohols mentioned above come into consideration.

Also suitable are hydroxyalkyl esters of saturated C ₃ to C _e hydroxycarboxylic acids such as hydroxyacetic acid glycol monoesters, lactic acid glycol monoesters and hydroxypivalic acid neopentylglycol esters.

Comonomers b) of maleic anhydride and ethylene glycol, polyethylene glycol with a molecular weight of up to 2,000, glycerol, diglycerol, triglycerol, tetraglycerol, and polyglycerols with a molecular weight of up to 2,000, pentaerythritol, monosaccharides, neopentylglycol, a, ω-diamines with 2 to 6 diamines with 2 to 6 diamines are preferably used. a, ω-diols with 3 to 6 carbon atoms, and hydroxypivalic acid neopentylglycol monoester used.

in der

• X = H, Alkalimetall oder eine Ammoniumgruppe und
• n = 1 bis 50 bedeutet.

Comonomers b) which are derived from ethylene glycol and α, ω-diols can be represented, for example, using the following formula:

in the

• X = H, alkali metal or an ammonium group and
• n = 1 to 50 means.

in der

• X = H, Alkalimetall oder eine Ammoniumgruppe und
• n = 0 bis 4 bedeutet, charakterisiert werden.

Comonomers b), which are formed by reacting maleic anhydride or maleic acid with a, ω-diamines, can, for example, using the following formula

in the

• X = H, alkali metal or an ammonium group and
• n = 0 to 4 means to be characterized.

Monoethylenically unsaturated C ₄ - to C _e -dicarboxylic acids are used as the monomer of component c). These are, for example, maleic acid, itaconic acid, citraconic acid, mesaconic acid, fumaric acid and methylene malonic acid. Maleic acid or itaconic acid are preferably used as Monomerc). The monomers c) make up 0 to 84.5, preferably 5 to 60 mol% of the copolymers.

The copolymers may optionally contain copolymerized hydroxyalkyl esters with 2 to 6 carbon atoms in the hydroxyalkyl group of monoethylenically unsaturated C ₃ to C _e carboxylic acids as component d). The hydroxyalkyl ester groups of this group of monomers are derived from polyhydric alcohols, for example glycol, glycerin, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 2,3-butanediol, mixtures of the Butanediols or propanediols, 1,6-hexanediol and neopentyl glycol. The polyhydric alcohols are reacted with monoethylenically unsaturated C ₃ - to C _e -carboxylic acids esterified. These are the carboxylic acids mentioned above under a) and c). Suitable as component d) are thus, for example, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxy-n-propyl methacrylate, hydroxy-n-propyl acrylate, hydroxyisopropyl acrylate, hydroxyisopropyl methacrylate, hydroxy-n-butyl acrylate, hydroxyisobutylacrylate, hydroxy-n-butyl methylacylate, hydroxymethyl acrylate, hydroxymethyl Hydroxypropyldimaleinate, hydroxy-n-butylmonomaleinate, hydroxy-n-butyldimaleinate and hydroxyethylmonoitaconate. Of the hydroxyalkyl esters of the monoethylenically unsaturated dicarboxylic acids, both the mono- and the diesters of the dicarboxylic acids with the polyhydric alcohols mentioned above can be used.

Preferably used as component d) is hydroxyethyl acrylate, hydroxyethyl methacrylate, butane-1,4-diol monoacrylate and the technical-grade mixtures of hydroxypropyl acrylates. Here are from The isomer mixtures of 2-hydroxy-1-propyl acrylate and 1-hydroxy-2-propyl acrylate are of particular technical importance. These hydroxyalkyl acrylates are produced by reacting acrylic acid with propylene oxide. The monomers of group d) are present in the copolymer in 0 to 20, preferably 0 to 15 mol% in polymerized form.

The copolymers may optionally contain, as component e), other water-soluble monoethylenically unsaturated monomers copolymerizable with a), b), c) and d). Suitable monomers of this type are, for example, acrylamide, methacrylamide, 2-acrylamido-2-methylpropanesulfonic acid, vinylsulfonic acid, allylsulfonic acid, vinylphosphonic acid, allylphosphonic acid, acrylonitrile, methacrylonitrile, dimethylaminoethyl acrylate, diethylaminoethylacrylate, diethylaminoethyl methacrylate, n-vinylazolonyl, nylon-vinylazolonyl, n-vinylpyronidyl, n-vinylpyronidyl, n-vinylpyronidyl, n-vinylpyronidyl, n-vinylpyronidyl, n-vinylpyronidyl, n-vinylpyronidyl, n-vinylpyronidyl, n-vinylpyronidyl, n-vinylpyronidyl, n-vinylpyronidyl, n-vinylpyronidyl, n-vinylpyridonyl, n-vinylpyronidol, n-vinylpyronidyl, n-vinylpyronidol, Vinylimidazoline, 1-vinyl-2-methyl-2-imidazoline, vinyl acetate and mixtures of the monomers mentioned. Those monomers in this group which contain acid groups can be used in the copolymerization in the form of the free acids or else in a form partially or completely neutralized with alkali metal bases or ammonium bases. The basic acrylates, such as diethylaminoethyl acrylate, are neutralized or quaternized with acids and then subjected to the copolymerization. The monomers e) make up 0 to 30, preferably 0 to 20, mol% of the copolymers. They only serve to modify the copolymers.

The sum of the data in mol% of components a) to e) is always 100. The copolymerization is carried out in an aqueous medium, preferably in a purely aqueous medium. It can be done according to different process variants, e.g. the monomers a) to e) can be polymerized batchwise in the form of aqueous solutions. In addition, it is possible to initially introduce some of the monomers and some of the initiator into the polymerization reactor, to warm them to the polymerization temperature under an inert gas atmosphere and then to add the remaining monomers and the initiator to the reactor after the polymerization has progressed. The polymerization temperatures range from 20 to 200 ° C. At temperatures above 100 ° C, pressure equipment is used. The polymerization temperature is preferably 50 to 150 ° C.

• b1) Maleinsäureanhydrid, Itaconsäureanhydrid, Citraconsäureanhydrid oder deren Gemische in einem Reaktor vorlegt und darin mit
• b2) mehrwertigen, 2 bis 6 C-Atome aufweisenden Alkoholen, wasserlöslichen oder wasserunlöslichen Polyalkylenglykolen eines Molekulargewichts bis etwa 400, wasserlöslichen Polyalkylenglykolen eines Molekulargewichts über etwa 400 bis 10.000, Polyglycerinen eines Molekulargewichts bis 2.000, Diaminen, Polyalkylenpolyaminen, Polyethyleniminen, Aminoalkoholen, Lysin, Serin, Copolymerisaten aus Alkylenoxid und Kohlendioxid, Polyvinylalkohol eines Molekulargewichts bis 10.000, Allylalkohol, Allylamin, Hydroxyalkylestem mit 2 bis 6 C-Atomen in der Hydroxyalkylgruppe von monoethylenisch ungesättigten C₃- bis C₃-Carbonsäuren oder von gesättigten C₃- bis C_e-Hydroxycarbonsäuren oder deren Mischungen bei Temperaturen von 50 bis 200°C umsetzt. Diese Umsetzung wird vorzugsweise in Abwesenheit von Wasser vorgenommen, geringe Mengen an Wasser stören dabei jedoch dann nicht, wenn die Komponente b1) in entsprechendem Überschuß eingesetzt wird. Anstelle von den unter b1) genannten Verbindungen kann man jedoch auch die sich davon ableitenden Mono- oder Diester mit C₁- bis C₄-Alkoholen einsetzen. In diesen Fällen wird eine Umesterung durchgeführt und vorzugsweise der dabei entstehende C₁- bis C₄-Alkohol aus dem Reaktionsgemisch abdestilliert. Bei Einsatz von Aminogruppen enthaltenden Verbindungen, die unter b2) genannt sind, entstehen bei der Umsetzung mit den Mono- oder Diestern der Säureanhydride gemäß b1) die entsprechenden Amide. Falls bei der Herstellung derComonomeren b) Ester der Komponente b1) eingesetzt werden, so sind dies vorzugsweise Maleinsäuredimethylester, Maleinsäuremonomethylester, Itaconsäuredimethylester, Maleinsäuremonoisopropylester und Maleinsäuredüsopropylester. Gegebenenfalls können übliche Veresterungskatalysatoren mitverwendet werden.

In a preferred embodiment of the production process, the comonomer b) is first prepared by

• b1) maleic anhydride, itaconic anhydride, citraconic anhydride or mixtures thereof are placed in a reactor and are included therein
• b2) polyhydric alcohols containing 2 to 6 carbon atoms, water-soluble or water-insoluble polyalkylene glycols with a molecular weight of up to approximately 400, water-soluble polyalkylene glycols with a molecular weight of more than approximately 400 to 10,000, polyglycerols with a molecular weight of up to 2,000, diamines, polyalkylene polyamines, polyethyleneimines, amino alcohols, lysine , Copolymers of alkylene oxide and carbon dioxide, polyvinyl alcohol with a molecular weight of up to 10,000, allyl alcohol, allylamine, hydroxyalkyl esters with 2 to 6 carbon atoms in the hydroxyalkyl group of monoethylenically unsaturated C ₃ to C ₃ carboxylic acids or of saturated C ₃ to C _e hydroxycarboxylic acids or their mixtures at temperatures of 50 to 200 ° C. This reaction is preferably carried out in the absence of water, but small amounts of water do not interfere when component b1) is used in a corresponding excess. Instead of the compounds mentioned under b1), however, it is also possible to use the mono- or diesters derived therefrom with C ₁ -C ₄ -alcohols. In these cases, a transesterification is carried out and the C ₁ to C ₄ alcohol formed is preferably distilled off from the reaction mixture. When using amino group-containing compounds mentioned under b2), the corresponding amides are formed in the reaction with the mono- or diesters of the acid anhydrides according to b1). If esters of component b1) are used in the preparation of the comonomers b), these are preferably dimethyl maleate, monomethyl maleate, dimethyl itaconate, monoisopropyl maleate and diisopropyl maleate. If necessary, customary esterification catalysts can also be used.

At least 0.5 mol of a compound of component b1) is used per mole of compounds b2). The temperature during the reaction is preferably 50 to 150 ° C. The reaction is carried out to such an extent that there is practically a quantitative conversion of component b2). Component b1), which is usually used in excess, can remain in the reaction mixture after the comonomer preparation has ended. In this case, the comonomer can be dissolved in a monoethylenically unsaturated C ₃ -C _e -monocarboxylic acid according to a) and then subjected to the copolymerization together with the unreacted part of component b1) and the other monomers. Since the copolymerization takes place in an aqueous medium, the excess dicarboxylic anhydride still present in the comonomer is hydrolyzed to the corresponding dicarboxylic acid in accordance with b1). This dicarboxylic acid is then to be understood as the comonomer c).

However, the comonomer b) initially prepared, which still contains excess dicarboxylic anhydride, can also remain in the reaction mixture in which it was produced and can first be dissolved therein by adding water or dilute aqueous sodium hydroxide solution. The dicarboxylic anhydride still present is hydrolyzed here. This monomer mixture is then copolymerized by adding the other comonomers. The copolymerization of the monomers a) to e) is carried out at a pH of the aqueous solution of 2 to 9, preferably 3 to 7. The monomers a), b) and c), which each contain carboxylic acid groups, can be copolymerized in the form of the free carboxylic acids or in neutralized, preferably in partially neutralized form, the degree of neutralization being 0 to 100, preferably 40 to 90 mol%. The neutralization is preferably carried out with alkali metal or ammonium bases. These include, for example, sodium hydroxide solution, potassium hydroxide solution, soda, potash or ammonium bases such as ammonia, C ₁ -C ₈ -alkylamines, dialkylamines such as dimethylamine, din-butylamine, dihexylamine, tertiary amines such as trimethylamine, triethylamine, tributylamine, triethanolamine and quaternized nitrogen bases, for example to understand tetramethylammonium hydroxide, trimethyllaurylammonium hydroxide and trimethylbenzylammonium hydroxide. Sodium hydroxide solution, potassium hydroxide solution or ammonia are preferably used for neutralization. However, the neutralization can also be carried out with alkaline earth metal bases, for example Ca hydroxide or MgC0 ₃ .

Water-soluble radical-forming compounds are preferably used as polymerization initiators, e.g. Hydrogen peroxide, peroxidisulfates and mixtures of hydrogen peroxide and peroxidisulfates. Suitable peroxydisulfates are, for example, lithium, sodium, potassium and ammonium peroxydisulfate. In the case of mixtures of hydrogen peroxide and peroxydisulfate, any ratio can be set, preferably hydrogen peroxide and peroxydisulfate in a weight ratio of 3: to 1: 3. Mixtures of hydrogen peroxide and sodium peroxydisulfate are preferably used in a weight ratio of 1: 1. The above-mentioned water-soluble polymerization initiators can optionally also be used in combination with reducing agents, e.g. Iron 11-sulfate, sodium sulfite, sodium hydrogen sulfite, sodium dithionite, triethanolamine and ascorbic acid can be used in the form of the so-called redox initiators. Suitable water-soluble organic peroxides are, for example, acetylacetone peroxide, methyl ethyl ketone peroxide, tert-butyl hydroperoxide and cumene hydroperoxide. The water-soluble organic peroxides can also be used with the reducing agents mentioned above. Other water-soluble polymerization initiators are azo starters, e.g. 2,2'-azobis (2-amidinopropane) dihydrochloride, 2,2'-azobis (N, N'-dimethylene) isobutyramidine dihydrochloride, 2- (carbamoylazo) isobutyronitrile and 4,4'-azo-bis- ( 4-cyanovaleric acid). The polymerization can also be started with water-insoluble initiators, such as dibenzoyl peroxide, dicyclohexyl peroxidicarbonate, dilauryl peroxide or azodiisobutyronitrile.

The initiators are used in amounts of 0.1 to 15, preferably 0.5 to 10,% by weight, based on the sum of the monomers used in the polymerization. The polymerization initiators can be added continuously or batchwise to the mixture to be polymerized either together with the monomers or separately in the form of aqueous solutions.

The copolymerization can optionally also be carried out in the presence of regulators. For this purpose, water-soluble compounds are preferably used which are either miscible with water in any ratio or dissolve more than 5% by weight therein at a temperature of 20.degree. Compounds of this type are, for example, aldehydes having 1 to 4 carbon atoms, such as formaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde and isobutyraldehyde, formic acid, ammonium formate, hydroxylammonium salts, in particular hydroxylammonium sulfate, compounds containing SH groups with up to 6 carbon atoms, such as thioglycolic acid, mercapto such as mercaptoethanol, mercaptopropanol, mercaptobutanols and mercaptohexanol, mono- and polyhydric alcohols with up to 6 carbon atoms, such as isopropanol, glycol, glycerin and isobutanol. Preferred regulators are water-soluble mercaptans, ammonium formate and hydroxylammonium sulfate. The regulators are used in amounts of 0 to 25% by weight, based on the sum of the monomers used in the polymerization. The particularly effective regulators, which are preferably used, are used in amounts of up to at most 15% by weight. If work is carried out in the presence of regulators, the minimum amount used is 0.2% by weight, based on the monomers to be polymerized.

• a) 99 bis 15 Mol% Acrylsäure, Methacrylsäure oder deren Mischungen,
• b) 0,5 bis 15 Mol% eines Comonomers aus b1) Maleinsäureanhydrid und b2) Ethylenglykol, Polyethylenglykol eines Molekulargewichts bis 2.000, Glycerin, Polyglycerinen eines Molekulargewichts bis 2.000, Pentaerythrit, Monosacchariden, Neopentylglykol, a,ro-Diaminen mit 2 bis 6 C-Atomen, α,ω-Diolen mit 3 bis 6 C-Atomen, Hydroxypivalinsäureneopentylglykolesteroder Mischungen aus diesen Verbindungen,
• c) 0 bis 84,5 Mol% Maleinsäure und/oder Itaconsäure und
• d) 0 bis 20 Mol% Hydroxypropylacrylaten, Hydroxypropylmethacrylaten, Hydroxyethylacrylat, Hydroxyethylmethacrylat, Hydroxybutylacrylaten, Hydroxybutylmethacrylaten oder deren Mischungen.

Polymer mixtures are preferably polymerized out

• a) 99 to 15 mol% of acrylic acid, methacrylic acid or mixtures thereof,
• b) 0.5 to 15 mol% of a comonomer from b1) maleic anhydride and b2) ethylene glycol, polyethylene glycol with a molecular weight up to 2,000, glycerol, polyglycerols with a molecular weight up to 2,000, pentaerythritol, monosaccharides, neopentyl glycol, a, ro-diamines with 2 to 6 C. Atoms, α, ω-diols with 3 to 6 C atoms, hydroxypivalic acid neopentylglycol esters or mixtures of these compounds,
• c) 0 to 84.5 mol% maleic acid and / or itaconic acid and
• d) 0 to 20 mol% of hydroxypropyl acrylates, hydroxypropyl methacrylates, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxybutyl acrylates, hydroxybutyl methacrylates or mixtures thereof.

• a) Acrylsäure und/oder Methacrylsäure,
• b) einem der oben genannten Comonomeren der Formel (I) oder (11) und
• c) Maleinsäure.

The preparation of copolymerization from is particularly preferred

• a) acrylic acid and / or methacrylic acid,
• b) one of the above-mentioned comonomers of the formula (I) or (11) and
• c) Maleic acid.

The copolymerization of monomers a) to e) gives aqueous polymer solutions which have a polymer content of up to 70% by weight. It is of course also possible to use very dilute e.g. To produce 1% aqueous solutions, but the copolymerization is carried out for economic reasons so that at least 20% by weight aqueous copolymer solutions are prepared. After the copolymerization, the solutions can be adjusted to a pH in the range from 6.5 to 7, provided that the polymerization has not been carried out in this range anyway. The copolymers can be obtained by evaporating the aqueous solutions. They have a low residual monomer content and are surprisingly biodegradable. The biodegradability of the copolymers according to the invention is up to 100% in accordance with DIN 38 412, part 24, static test (L25), and is generally between 20 and 95%.

The copolymers are water-soluble. If they do not dissolve in water in the free acid form, they can be converted into a water-soluble form by partial or complete neutralization with NaOH, KOH, ammonia or amines. Copolymers, their alkali or ammonium salts, of which at least 20 g per liter of water dissolve at a temperature of 20 ° C, are referred to in the present context as water-soluble. The copolymers surprisingly have the advantage that, in the range of low polymer concentrations, they show no precipitation in the aqueous solutions containing Ca and / or Mg ions. It is therefore possible to prepare stable solutions of the copolymers in drinking water without the alkaline earth salts of the copolymers being precipitated.

The K value of the copolymers is in the range from 8 to 120, preferably 12 to 100. The K values of the copolymers are in each case on the sodium salt in aqueous solution at 25 ° C., a pH of 7 and a polymer concentration of the sodium salt of Copolymer determined from 1 wt.%. If the copolymers are in the form of other salts or free acids, they must first be converted into the sodium salts before the K value is determined.

The copolymers described above are used according to the invention as additives to detergents and cleaning agents. They can be added in powder or liquid formulations. The detergent and cleaning agent formulations are usually based on surfactants and, if appropriate, builders. Builders are usually not used for pure liquid detergents. Suitable surfactants are, for example, anionic surfactants such as C ₃ to C ₁₂ alkylbenzenesulfonates, C ₁₂ to C ₁₈ alkanesulfonates, C ₁₂ to C ₁₆ alkyl sulfates, C ₂ to C ₁₆ alkyl sulfosuccinates and sulfated ethoxylated C ₁₂ to C ₁₆ alkanols, furthermore nonionic surfactants, such as C ₈ to C ₁₂ alkylphenol ethoxylates, C ₁₂ -C ₂₀ alkanol alkoxylates, and block copolymers of ethylene oxide and propylene oxide. The end groups of the polyalkylene oxides can optionally be closed. This is understood to mean that the free OH groups of the polyalkylene oxides can be etherified, esterified, acetalized and / or aminated. Another modification possibility is that the free OH groups of the polyalkylene oxides are reacted with isocyanates.

The nonionic surfactants also include C ₄ -C ₁₈ -alkyl glucosides and the alkoxylated products obtainable therefrom by alkoxylation, in particular those which can be prepared by reacting alkyl glucosides with ethylene oxide. The surfactants that can be used in detergents can also have a zwitterionic character and represent soaps. The surfactants are generally present in an amount of 2 to 50, preferably 5 to 45,% by weight of the detergents and cleaners.

Builders contained in the detergents and cleaning agents are, for example, phosphates, e.g. orthophosphate, pyrophosphate and especially pentasodium triphosphate, zeolites, soda, polycarboxylic acids, nitrilotriacetic acid, citric acid, tartaric acid, the salts of the acids mentioned and monomeric, oligomeric or polymeric phosphonates. The individual substances are used in different amounts to produce the detergent formulations, e.g. Soda in quantities up to 80%, phosphates in quantities up to 45%, zeolites in quantities up to 40%, nitrilotriacetic acid and phosphonates in quantities up to 10% and polycarboxylic acids in quantities up to 20%, each based on the weight of the substances as well on the entire detergent formulation. Because of the severe environmental pollution that the use of phosphates entails, the phosphate content in detergents and cleaning agents is increasingly reduced, so that detergents today contain up to a maximum of 25% phosphate or are even preferably phosphate-free.

The biodegradable copolymers can also be used as an additive to liquid detergents. Liquid detergents usually contain, as a mixing component, liquid or solid surfactants which are soluble or at least dispersible in the detergent formulation.

Suitable surfactants for this are the products which are also used in powder detergents, and liquid polyalkylene oxides or polyalkoxylated compounds.

Detergent formulations can also contain corrosion inhibitors, such as silicates, as further additives. Suitable silicates are, for example, sodium silicate, sodium disilicate and sodium metasilicate. The corrosion inhibitors can be present in the detergent and cleaning agent formulation in amounts of up to 25% by weight. Other common additives for detergents and cleaning agents are bleaches, which can be present in an amount of up to 30% by weight. Suitable bleaching agents are, for example, perborates or chlorine-releasing compounds, such as chloroisocyanurates. Another group of additives, which can optionally be contained in detergents, are graying inhibitors. Known substances of this type are carboxymethyl cellulose, methyl cellulose, hydroxypropyl methyl cellulose and graft polymers of vinyl acetate onto polyalkylene oxides with a molecular weight of 1000 to 15 000. Graying inhibitors can be present in the detergent formulation in amounts of up to 5%. Other common additives for detergents, which may or may not be included, are optical brighteners, enzymes and perfume. The powder detergents can also contain up to 50% by weight of an adjusting agent, such as sodium sulfate. The detergent formulations can be anhydrous or small amounts, e.g. contain up to 10% by weight of water. Liquid detergents usually contain up to 80% by weight of water. Usual detergent formulations are described in detail, for example, in DE-OS 35 14 364, to which express reference is made.

The biodegradable copolymers described above can be added to all detergent and cleaning agent formulations. The amounts used for this are between 0.5 and 25, preferably between 1 and 15% by weight, based on the overall formulation. The amounts of biodegradable copolymers used are in most cases preferably 2 to 10% by weight, based on the detergent and cleaning agent mixture. The use of the additives to be used according to the invention in phosphate-free and low-phosphate washing and cleaning agents is of particular importance. The low-phosphate formulations contain up to a maximum of 25% by weight of pentasodium triphosphate or pyrophosphate. Because of the biodegradability, the copolymers to be used according to the invention are preferably used in phosphate-free formulations

If desired, the biodegradable copolymers to be used according to the invention can be used in detergent formulations together with non-biodegradable copolymers of acrylic acid and maleic acid or homopolymers of acrylic acid. The last-mentioned biodegradable polymers have hitherto been used as incrustation inhibitors in detergent formulations. In addition to the polymers already mentioned, copolymers of C ₃ to C _e mono- and dicarboxylic acids or maleic anhydride and C ₁ to C ₄ -alkyl vinyl ethers are also suitable. The molecular weight of the homopolymers and copolymers is 1000 to 100,000. If desired, these incrustation inhibitors can be used in detergents in an amount of up to 10% by weight, based on the overall formulation, in addition to the biodegradable copolymers to be used according to the invention. Although the known incrustation inhibitors based on the above-mentioned polymers are not biodegradable, they can nevertheless be removed from the waste water in sewage treatment plants together with the activated sludge to which they are adsorbed. The biodegradable copolymers can be added to detergent formulations both in the form of the free acids, in completely neutralized form or in partially neutralized form.

The K values given in the examples were determined according to H. Fikentscher, Cellulosechemie, Vol. 13, 58-64 and 71-74 (1932). K = k-10 ^3. The measurements were in all cases on the sodium salt in aqueous solution at 25 ° C, a pH of 7 and a polymer concentration of the sodium salt of 1% by weight.

Examples Production of the biodegradable copolymers General manufacturing instructions

In a glass reactor equipped with a stirrer, thermometer, nitrogen inlet and 3 feed vessels, of which one feed vessel can be heated and stirred, 98 g (1 mol) each Maleic anhydride dissolved in 500 ml of 4 molar aqueous sodium hydroxide solution and heated to a temperature of 90 _° C. At the same time, 0.1 g of p-toluenesulfonic acid and the polyhydric alcohols indicated in Table 1 are added to 98 g (1 mol) of maleic anhydride in the heatable feed vessel and under a nitrogen atmosphere within 0.5 to 3.5 hours at temperatures in the range melted from 60 to 120 ° C.

The copolymerization is carried out at a temperature of 90 ° C within 5 hours by taking the amount of sodium acrylate shown in Table 1 as a 35% aqueous solution, the melt of the comonomers (from maleic anhydride and polyhydric alcohol and unreacted maleic anhydride) and over a period of 6 Hours, starting with the monomer feed, can also continuously run in 90 g of 30% hydrogen peroxide in 100 ml of water. A viscous, aqueous solution is obtained which is polymerized at a temperature of 90 ° C. for 1 hour after the addition of the initiator has ended. After cooling with 25% aqueous sodium hydroxide solution, the aqueous solution is adjusted to a pH of 6.5. The starting materials, the K values, the residual maleic acid content and the data on the biodegradability of the copolymers are given in Table 1.

Polyethylene glycol with a molecular weight of 400 was used to prepare the copolymers 11 to 13.

For the copolymers indicated under Nos. 2, 9, 11 and 16 in Table 1, the precipitation behavior at pH 7.5 was tested in aqueous solutions which contained 10 to 10,000 mgll of Ca ions (in the form of CaCl ₂ ). The following Ca ion concentrations were tested: 10, 50, 75, 100, 150, 500, 1000 and 10,000 mg / l. The copolymer concentrations were varied from 0.1 to 7 mg / l (the following concentrations were tested: 0.1; 0.5; 1.0; 2; 3; 4 and 7 mg copolymer water). No precipitation occurred even after the aqueous solutions of the copolymers had been stored for 20 days in the presence of Ca ions, while a copolymer of 30% by weight maleic acid and 70% by weight acrylic acid with a K value of 60 always failed under the test conditions specified.

(hergestellt nach I. Bauchop und S.R. Elsden_i J. gen. Hikrobiol. 23, 457-469 (1960) .The biodegradability of the copolymers was also demonstrated by bacterial growth tests. For this purpose, an enrichment medium was prepared on solid nutrient media and solidified with 18 g / l agar. The enrichment medium had the following composition:

(produced according to I. Bauchop and SR Elsden _i J. gen. Hikrobiol. 23, 457-469 (1960).

The copolymers described in Table 1 under Nos. 1 to 16 were added to the nutrient media in each case in concentrations of 10 g / l.

Soil samples were either placed in liquid medium and shaken there for 7 days at 30 ° C, or placed as an aqueous suspension directly on solid culture media and also incubated at 30 ° C. The enrichment cultures in liquid medium were transferred to solid culture media after 7 days. Colonies that were growing well were vaccinated from these plates and checked for uniformity in the separating smear.

In this way, pure bacterial cultures were isolated which clearly showed growth on the copolymers examined.

If, on the other hand, the bacterial growth experiments described above were carried out for comparison with a copolymer of 30% by weight maleic acid and 70% by weight acrylic acid with a K value of 60, no bacterial growth could be detected.

The mode of action of the biodegradable copolymers to be used according to the invention in washing and cleaning agents is explained in the following examples. The effect of the biodegradable copolymers as a builder is due to the properties of these polymers to inhibit incrustations on the laundry, to increase the washing power of the detergents and to reduce the graying of white test material when washing in the presence of dirty fabric.

For this purpose, test fabrics are subjected to multiple washes in detergent formulations with a wide variety of builder structures, the detergent formulations once containing the biodegradable copolymer to be used according to the invention and, for comparison with the prior art, a copolymer of acrylic acid and maleic acid previously used. The last three washes in a series were carried out with the addition of standard soiling fabric. The reduction in whiteness of the test fabric is a measure of the graying. The increase in whiteness of the dirty fabric is a measure of the washing power of the detergent used and is determined photometrically as a percent reflectance

Incrustation values are obtained by ashing the polyester / cotton blend or the cotton terry fabric after the test. The ash content is given in percent by weight. The more effective the polymer contained in the detergent, the lower the ash content of the test fabric. Depending on the effectiveness of the basic structure of the detergent used, different amounts of use of the biodegradable copolymers to be used according to the invention are necessary.

Test conditions

• Device: Launder-O-Meter from Atlas, Chicago
• Number of wash cycles: 20
• Wash liquor: 250 ml, the water used has 4 mmol hardness per liter (calcium to magnesium equals 4: 1)
• Washing time: 30 minutes at 60 ° C (including heating up time)
• Detergent dosage: 8 gll
• Test fabric: 5 g polyester (stock no. 655) 5 g polyester / cotton (stock no. 766) 5 g cotton terry cloth (stock no. 295)
• Dirt tissue: 5 g WFK 10 D, 10 C and 20 D (standard dirt tissue from the Institute for Laundry Research Krefeld, Adlerstr. 44) or EMPA 104 (standard dirt tissue from Eigenössische Materialprüfungsanstalt, St. Gallen (CH)) (see table )

This dirt tissue was added in the 18th to 20th wash cycle. The detergent formulations 1 to 29 shown in Table 2 were prepared and investigated.

The photometric measurement of the reflectance in% was carried out in the present case on the Elrepho 2000 (Datacolor) at the wavelength of 460 nm (barium primary white standard according to DIN 5033).

The detergent formulations given in Tables 2 and 3 were tested according to the test methods given above. For comparison with the prior art, the detergent formulations either contained no copolymer or copolymer No. 17 (copolymer according to EP-PS 25 551 from acrylic acid and maleic acid). The detergent formulations used in each of the examples and comparative examples and the results obtained therewith are given in Tables 4 to 5.

Table 5 shows that the copolymers to be used according to the invention, which were used in Examples 22, 23 and 24, have a better primary washing action than the copolymer 17 (copolymer according to the prior art) in the comparable detergent formulations according to Comparative Examples 40 to 45 demonstrate.

Claims (6)

1. The use of a water-soluble copolymer which contains

a) from 99.5 to 15 mol% of one or more monoethylenically unsaturated C₃- to C₆-monocarboxylic acids,

b) from 0.5 to 20 mol% of one or more comonomers which contain two or more ethylenically unsaturated nonconjugated double bonds and which have one or more -CO-OX groups where X is hydrogen, an alkali metal, one equivalent of an alkaline earth metal or ammonium,

c) from 0 to 84.5 mol% of one or more monoethylenically unsaturated C₄- to C₈-dicarboxylic acids,

d) from 0 to 20 mol% of one or more hydroxyalkyl esters of from 2 to 6 carbon atoms in the hydroxyalkyl group of monoethylenically unsaturated C₃- to C₈-carboxylic acids and

e) from 0 to 30 mol% of other water-soluble, monoethylenically unsaturated monomers copolymerizable with a), b), c) and d)
as copolymerized units, with the proviso that the sum of the mol% ages a) to e) is always 100, and which has a K value of from 8 to 120 (determined on the sodium salt by the Fikentscher method on a 1% strength by weight aqueous solution at 25°C and pH 7) as an additive in detergents in an amount of from 0.5 to 25% by weight.

2. A surfactant based detergent which contains a copolymer which contains

a) from 99.5 to 15 mol% of one or more monoethylenically unsaturated C₃- to C_e-monocarboxylic acids,

b) from 0.5 to 20 mol% of one or more comonomers which contain two or more ethylenically unsaturated nonconjugated double bonds and which have one or more -CO-OX groups where X is hydrogen, an alkali metal, one equivalent of an alkaline earth metal or ammonium,

c) from 0 to 84.5 mol% of one or more monoethylenically unsaturated C₄- to C₆-dicarboxylic acids,

d) from 0 to 20 mol% of one or more hydroxyalkyl esters of from 2 to 6 carbon atoms in the hydroxyalkyl group of monoethylenically unsaturated C₃- to C_e-carboxylic acids and

e) from 0 to 30 mol% of other water-soluble, monoethylenically unsaturated monomers copolymerizable with a), b), c) and d)
as copolymerized units, with the proviso that the sum of the mol% ages a) to e) is always 100, and which has a K value of from 8 to 120 (determined on the sodium salt by the Fikentscher method on a 1% strength by weight aqueous solution at 25°C and pH 7).

3. A detergent as claimed in claim 2 which contains from 0.5 to 25% by weight of a water-soluble copolymer which contains

a) from 99.5 to 80 mol% of one or more monoethylenically unsaturated C3- to C6-monocarboxylic acids and

b) from 0.5 to 20 mol% of one or more comonomers which are obtainable by reaction of

b1) maleic anhydride, itaconic anhydride, citraconic anhydride or mixtures thereof with

b2) polyhydric C₂- to C_o-alcohols, water-soluble or water-insoluble polyalkylene glycols having a molecular weight of up to 400, water-soluble polyalkylene glycols having a molecular weight of from above 400 to 10,000, polyglycerols having a molecular weight of up to 2,000, polyamines, polyalkylene polyamines, polyethylene-imines, amino alcohols, hydroxy-amino- or -diaminocarboxylic acids, copolymers of alkylene oxide and carbon dioxide, polyvinyl alcohol having a molecular weight of up to 10,000, allyl alcohol, allylamine, hydroxyalkyl esters having from 2 to 6 carbon atoms in the hydroxyalkyl group of monoethylenically unsaturated C3- to C6-carboxylic acids or saturated C3- to C6-hydroxycarboxylic acids or mixtures thereof,
as copolymerized units and have a K value of from 8 to 120.

4. A detergent as claimed in claim 2 which contains a water-soluble copolymer which contains

a) from 99 to 15 mol% of one or more monoethylenically unsaturated C₃- to C_e-monocarboxylic acids,

b) from 0.5 to 15 mol% of one or more comonomers which contain two or more ethylenically unsaturated nonconjugated double bonds and have one or more -CO-OX groups where X is hydrogen, an alkali metal, one equivalent of an alkaline earth metal or ammonium, and

c) from 0.5 to 84.5 mol% of one or more monoethylenically unsaturated C₄- to C₈-dicarboxylic acids as copolymerized units, with the proviso that the sum of the mol% ages a) to c) is always 100 and which has a K value of from 12 to 100 (determined on a 1% strength by weight aqueous solution of the Na salt of the copolymer at 25°C and pH 7 by the Fikentscher method).

5. A detergent as claimed in any of claims 2 to 4 which contains from 1 to 15% by weight of a copolymer which contains as monomer b) one or more compounds of the formula

or

where

X is H, an alkali metal or an ammonium group,

n is from 1 to 120 and

m is from 0 to 4,

in polymerized form.

6. A detergent as claimed in any of claims 2 to 5 which is phosphate-free and contains one or more copolymers in an amount of from 2 to 10% by weight.