Graftcopolymer of monosaccharides, oligosaccharides, polysaccharides and modified polysaccharides, process of preparing same and its application.

0001US Pat. No. 3,558,499 discloses detergents which contain as essential constituents about 10 to about 25% of an anionic or nonionic surface-active agent, about 60 to about 89.9% of an inorganic builder, such as sodium tripolyphosphate, sodium carbonate or sodium silicate and about 0 , 1 to about 10% by weight of a graying inhibitor. The graying inhibitor consists of a graft polymer of starch with acrylic acid or methacrylic acid. The content of polymerized acrylic acid or methacrylic acid in the graft polymer is about 1 to 50%.

0002JP-A-55/155 097 detergent formulations are known which contain 0.05 to 5% by weight of a grafted starch to suppress the re-soiling of laundry during washing, which by polymerizing 0.5 to 100 parts by weight of a water-soluble monomers or monomers which become water-soluble by hydrolysis in the presence of 100 parts by weight of starch. According to the information in the examples, an oxidized starch grafted with sodium acrylate (8 parts by weight of sodium acrylate per 100 parts by weight of oxidized starch) and an oxidized starch grafted with hydroxypropyl methacrylate (2.5 parts by weight of hydroxypropyl acrylate per 100 parts by weight) Parts of starch) and a corn starch-polyvinyl alcohol graft polymer (100 parts by weight of corn starch / 5 parts by weight of vinyl acetate, 63% degree of hydrolysis).

0003JP-A-61/031 498 discloses detergents which contain 0.5 to 50% by weight of graft polymers of a monosaccharide and / or an oligosaccharide and a water-soluble ethylenically unsaturated monomer as a builder. According to the examples, acrylic acid was grafted onto sucrose or glucose. As the examples and comparative examples of this publication show, adding polyacrylic acid to a detergent formulation increases the washing power more than adding the same amount of a starch grafted with acrylic acid or methacrylic acid. In contrast to the practically non-biodegradable polyacrylic acid, the grafted starches are said to be largely biodegradable.

0004EP-PS 0 075 820 discloses the preparation of copolymers from monoethylenically unsaturated dicarboxylic acids and monoethylenically unsaturated monocarboxylic acids. In this known production process, the degree of neutralization of the carboxylic acid groups of the monomers during the polymerization is 20 to 80%. This gives copolymers with low levels of residual dicarboxylic acid.

0005EP-PS 0 025 551 discloses the use of copolymers of, for example, maleic acid and acrylic acid as incrustation inhibitors in detergents.

0006The object of the present invention is to provide new substances which, when used in detergents, have an improved effectiveness compared to comparable known products. The new substances should also be as largely biodegradable as possible or at least eliminable from the wastewater from sewage treatment plants. Another goal is the use of high amounts of renewable raw materials to further improve ecological acceptance with a comparable property profile to purely synthetic detergent additives.

0007The object is achieved according to the invention with graft copolymers of monosaccharides, oligosaccharides, polysaccharides and derivatives which are obtainable by free-radical copolymerization of<ul id="ul0001" list-style="none"><li>(A) monomer mixtures<ul id="ul0002" list-style="none"><li>(a) 90 to 10% by weight of monoethylenically unsaturated C₄ to C₈ dicarboxylic acids, their anhydrides or alkali and / or ammonium salts,</li><li>(b) 10 to 90% by weight of monoethylenically unsaturated C₃ to C₁₀ carboxylic acids or their alkali and / or ammonium salts,</li><li>(c) 0 to 40% by weight of other monoethylenically unsaturated monomers which are copolymerizable with the monomers (a) and (b), and</li><li>(d) 0 to 5% by weight of at least two monomers containing ethylenically unsaturated double bonds in the molecule</li></ul> in the presence of</li><li>(B) monosaccharides, oligosaccharides, polysaccharides, thermally and / or mechanically treated, oxidatively, hydrolytically or enzymatically degraded polysaccharides, oxidized hydrolytically or enzymatically degraded polysaccharides, chemically modified mono-, oligo- and polysaccharides or mixtures of the compounds mentioned</li></ul> in the weight ratio (A): (B) from (95 to 20): (5 to 80).

0008These graft copolymers are used as additives for washing and cleaning agents in amounts of 0.1 to 20% by weight, based on the respective formulations.

0009The graft copolymers can be obtained by copolymerizing (A) monomer mixtures in the presence of (B) natural products based on mono-, oligo- and polysaccharides and their derivatives. The monomer mixtures (A) contain as monomers of group (a) monoethylenically unsaturated C₄ to C₈ dicarboxylic acids, their anhydrides or the alkali and / or ammonium salts of the dicarboxylic acids. Suitable dicarboxylic acids are, for example, maleic acid, fumaric acid, itaconic acid, mesaconic acid, methylene malonic acid, citraconic acid, maleic anhydride, itaconic anhydride and methylene malonic anhydride. The ethylenically unsaturated dicarboxylic acids can be used in the form of the free acids or in a form neutralized with alkali metal bases, ammonia or amines in the copolymerization. Preferably used as the monomer of group (a) is maleic acid, maleic anhydride, itaconic acid, itaconic anhydride and the sodium, potassium or ammonium salts of maleic acid or itaconic acid. These salts can be obtained, for example, from maleic anhydride or itaconic anhydride in a simple manner by neutralizing the anhydrides mentioned in aqueous solution with sodium hydroxide solution, potassium hydroxide solution or ammonia. The monomers of group (a) are present in the monomer mixture in an amount of 10 to 90, preferably 12 to 80% by weight and particularly preferably 15 to 60% by weight.

0010Suitable monomers of group (b) are monoethylenically unsaturated C₃ to C₁₀ carboxylic acids and their alkali and / or ammonium salts. These monomers include, for example, acrylic acid, methacrylic acid, dimethylacrylic acid, ethyl acrylic acid, allylacetic acid and vinyl acetic acid. From this group of monomers, preference is given to using acrylic acid, methacrylic acid, their mixtures and the sodium, potassium or ammonium salts or mixtures thereof.

0011The monomers of group (c) which are optionally used in the graft copolymerization include, for example, C₁ to C₆ alkyl and hydroxyalkyl esters of the compounds mentioned under (a) and (b), for example Methyl acrylate, ethyl acrylate, n-butyl acrylate, methyl methacrylate, maleic acid monomethyl ester, maleic acid dimethyl ester, maleic acid monoethyl ester, maleic acid diethyl ester, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxyethyl methacrylate and hydroxypropyl methacrylate. In addition, the amides and N-substituted alkylamides of the compounds given under (a) and (b) are suitable as monomers of group (c), for example Acrylamide, methacrylamide, N-alkylacrylamides with 1 to 18 carbon atoms in the alkyl group, such as, for example, N-methylacrylamide, N-dimethylacrylamide, N-tert.-butylacrylamide, N-octadecylacrylamide, maleic acid monoethylhexylamide, maleic acid monododecylamide, dimethylaminopropyl methacrylamide and acrylamide. Also suitable as monomers of group (c) are monomers containing sulfo groups, such as, for example, vinylsulfonic acid, allylsulfonic acid, methallylsulfonic acid, styrenesulfonic acid, 3-sulfopropyl acrylate, 3-sulfopropyl methacrylate and acrylamidomethylpropanesulfonic acid, and monomers containing phosphonic acid groups, such as vinylphosphonic acid and acrylamide phosphonyl allyl This group of monomers also includes N-vinylpyrrolidone, N-vinylcaprolactam, N-vinylformamide, N-vinyl-N-methylformamide, 1-vinylimidazole, 1-vinyl-2-methylimidazole, vinyl acetate and vinyl propionate. Also suitable as monomers of group (c) are the esters of alkoxylated C₁ to C₁₈ alcohols which have been reacted with 2 to 50 moles of ethylene oxide, propylene oxide, butylene oxide or mixtures thereof, with the monoethylenically unsaturated carboxylic acids of groups (a) and ( b), e.g. the esters of acrylic acid, methacrylic acid or maleic acid with a C₁₃ / C₁₅ oxo alcohol which has been reacted with different amounts of ethylene oxide, for example 3 mol, 5 mol, 7 mol, 10 mol or 30 mol ethylene oxide.

0012Both the mono- and the diesters of the dicarboxylic acid esters come into consideration.

0013Also come as monomers of group (c) amides of monoethylenically unsaturated C₃ to C₈ carboxylic acids with amide groups of the structure<chemistry id="chem0001" num="0001"><img file="EP0441197A2_D0001.tif" /></chemistry> considered in the<chemistry id="chem0002" num="0002"><img file="EP0441197A2_D0002.tif" /></chemistry> R³, R⁴ = H, CH₃, C₂H₅, R = C₁ to C₂₈ alkyl, n = 2 to 100 and R² = H, R¹ mean.

0014The monomers of component (c) are only used, if appropriate, for modifying the graft copolymers and in such cases they contain up to 40% by weight in the monomer mixtures used in the polymerization.

0015The preferred monomers of group (c) are hydroxyethyl acrylate. Hydroxypropyl acrylates, vinyl acetate, N-vinyl pyrrolidone and acrylamidomethyl propanesulfonic acid.

0016A further modification of the graft copolymers can be achieved in that the monomer mixtures optionally contain up to 5% by weight of a monomer having at least two ethylenically unsaturated non-conjugated double bonds in the molecule. These compounds are usually used as crosslinkers in copolymerizations. They can be added to the monomer mixtures from (a) and (b) used for the copolymerization or to the monomer mixtures from (a), (b) and (c). When used, the amount preferably used is 0.05 to 2% by weight. The use of the monomers of group (d) during the copolymerization increases the K values ​​of the copolymers. Suitable compounds of this type are, for example, methylenebisacrylamide, esters of acrylic acid and methacrylic acid with polyhydric alcohols, for example glycol diacrylate, glycerol triacrylate, glycol dimethacrylate, glycerol trimethacrylate, and polyols esterified at least twice with acrylic acid or methacrylic acid, such as pentaerythritol and glucose. Suitable crosslinkers are also divinylbenzene, divinyldioxane, pentaerythritol triallyl ether and pentaallylsucrose. From this group of compounds, preference is given to using water-soluble monomers, such as glycol diacrylate or glycol diacrylates of polyethylene glycols having a molecular weight of up to 3,000.

0017The polymerization of the monomers (a) and (b) and, if appropriate, additionally (c) and (d) takes place in the presence of natural products based on polysaccharides, oligosaccharides, monosaccharides and their derivatives. The natural substances are, for example Saccharides of plant or animal origin or products of the metabolism of microorganisms and their degradation and modification products which are already dispersible or soluble in water or alkalis or during the polymerization of the monomers (a) and (b) and optionally (c) and / or (d ) become dispersible or soluble directly or in partial or completely neutralized form with alkalis, ammonia or amines.

0018These are, for example, pectin, algin, chitin, chitosan, heparin, carrageenan, agar, gum arabic, tragacanth, karaya gum, ghatti gum, locust bean gum, guar gum, tara gum, inulin, xanthan, dextran, nigeran and pentosans such as Xylan and araban, the main components of which are D-glucuronic acid, D-galacturonic acid, D-galacturonic acid methyl ester, D-mannuronic acid, L-guluronic acid, D- and L-galactose, 3,6-anhydro-D-galactose, L-arabinose, L- Rhamnose, D-glucuronic acid, D-xylose, L-fucose, D-mannose, D-fructose and D-glucose, 2-amino-2-deoxi-D-glucose and 2-amino-2-deoxi-D-galactose and their N-acetyl derivatives.

0019From an economic point of view, the polysaccharides of component (B) used in the graft copolymerization are preferably starch, thermally and / or mechanically treated starch, oxidatively, hydrolytically or enzymatically degraded starches, oxidized hydrolytically or oxidized enzymatically degraded starches, and also chemically modified starches and chemically modified starches Monosaccharides and oligosaccharides. In principle, all strengths are suitable. However, starches from corn, wheat, rice, tapioca and in particular starch from potatoes are preferred. The starches are practically insoluble in water and can be converted into a water-soluble form in a known manner by thermal and / or mechanical treatment or by enzymatic or acid-catalyzed degradation. The following compounds may be mentioned as starch degradation products, which are obtainable either by oxidative, hydrolytic or enzymatic degradation of starch: dextrins, such as white and yellow dextrins, maltodextrins, glucose syrups, maltose syrups, hydrolysates with a high content of D-glucose and maltose and D Glucose and its isomerization product fructose. Mono- and oligosaccharides, such as galactose, mannose, ribose, sucrose, raffinose, lactose and trehalose, and cellulose degradation products, for example cellubiose and its oligomers, are of course also suitable as component (B).

0020Colorless or only slightly yellow-colored aqueous solutions of the graft polymer list are obtained in particular when starches which have been degraded by acid catalytic or enzymatic means are used as component (B). Such degraded starches are commercially available under the name starch saccharification products. They contain 0.5 to 95, preferably 8 to 20% by weight of dextrose and 3 to 30, preferably 5 to 20% by weight of maltose, 2 to 90% by weight of maltotriose and higher sugars.

0021Oxidized starches, such as, for example, dialdehyde starch and oxidized starch degradation products, such as, for example, gluconic acid, glucaric acid and glucuronic acid, are also suitable as component (B). Such compounds are obtained, for example, by oxidizing starch with periodate, chromic acid, hydrogen peroxide, nitrogen dioxide, nitrogen tetroxide, nitric acid or hypochlorite.

0022Also suitable as component (B) are chemically modified polysaccharides, in particular chemically modified starches, for example starches and starch degradation products converted with acids to esters and with alcohols to ethers. The esterification of these substances is possible both with inorganic and with organic acids, their anhydrides or chlorides. In the case of direct esterification, the water released leads to acid-catalyzed cleavage of glycosidic bonds. Phosphated and acetylated starches and starch degradation products are of particular technical interest. The most common method for etherifying starch is to treat the starch and the starch degradation products with organic halogen compounds, epoxides or sulfates in aqueous alkaline solution. Starch ethers are, for example, the alkyl ethers, hydroxyalkyl ethers, carboxyalkyl ethers and allyl ethers of starch. Chemically modified starches according to component (B) are also to be understood as meaning cationically modified starches, for example starches reacted with 2,3-epoxypropyltrimethylammonium chloride, as described, for example, in US Pat. No. 3,649,616.

0023Chemically modified polysaccharides also include, for example, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl hydroxyethyl cellulose, sulfoethyl cellulose, carboxymethyl sulfoethyl cellulose, hydroxypropyl sulfoethyl cellulose, hydroxyethyl sulfoethyl cellulose, methyl sulfoethyl cellulose and ethyl sulfoethyl cellulose.

0024Particularly suitable as component (B) are chemically modified degraded starches, for example hydrogenation products of starch hydrolysates, such as sorbitol and mannitol, maltitol and in particular hydrogenated glucose syrups, because they can be used to produce colorless graft copolymers which do not change color even after prolonged storage. Oxidized, hydrolytically degraded or oxidized, enzymatically degraded starches are also suitable as component (B).

0025The products of acid-catalyzed or enzymatic re-glycosidation or glycosidation, such as methyl glucoside, are also suitable.

0026To prepare the graft copolymers, the monomers (a) and (b) and optionally (c) and (d) are polymerized by free radicals in the presence of compounds of component (B). In some cases, it may be favorable for the effect of the graft polymer formed to use two or more of the compounds indicated under (B), for example Mixtures of hydrolytically or enzymatically degraded starches and gluconic acid, mixtures of a monosaccharide and an oligosaccharide, mixtures of an enzymatically degraded starch and a monosaccharide or mixtures of glucose and sucrose or mannose. The polymerization can be carried out in the presence or in the absence of inert solvents or inert diluents. Since the polymerization in the absence of inert solvents or diluents usually leads to non-uniform graft copolymers, the graft copolymerization in an inert solvent or diluent is preferred. Suitable inert diluents are, for example, in which the compounds indicated under (B) can be suspended and which dissolve the monomers (A). In these cases, the graft copolymers are in suspended form after the copolymerization and can easily be isolated by filtration in solid form. Suitable inert diluents are, for example, toluene, xylene, o-, m-, p-xylene and isomer mixtures, ethylbenzene, aliphatic hydrocarbons, such as pentane, hexane, heptane, octane, nonane, dodecane, cyclohexane, cyclooctane, methylcyclohexane and mixtures of the hydrocarbons mentioned or Gasoline fractions that do not contain polymerizable monomers. Chlorinated hydrocarbons such as chloroform, carbon tetrachloride, hexachloroethane, dichloroethane and tetrachloroethane are also suitable. In the procedure described above, in which the compounds of component (B) are suspended in an inert diluent, preference is given to using anhydrous compounds of component (B) and preferably using the anhydrides from the group of monomers (a). A preferred way of producing the graft copolymers is solution polymerization, the compounds of component (B), the monomers (A) and the graft copolymer formed being at least dispersed, preferably in dissolved form. For example, inert solvents, such as methanol, ethanol, isopropanol, n-propanol, n-butanol, sec-butanol, tetrahydrofuran, dioxane, and mixtures of the inert solvents mentioned are suitable for the solution polymerization. The copolymerization can be carried out continuously or batchwise. As already mentioned above, components (A) and (B) can also be copolymerized in the absence of inert diluents or solvents. Continuous polymerization at temperatures of 160 to 250 ° C is particularly suitable for this. If necessary, it is possible to work in the absence of polymerization initiators. However, preference is also given to using catalysts which form free radicals under the polymerization conditions, for example inorganic and organic peroxides, persulfates, azo compounds and so-called redox catalysts.

0027The graft copolymers are generally prepared using free-radical initiators.

0028Suitable radical initiators are preferably all those compounds which have a half-life of less than 3 hours at the polymerization temperature chosen in each case. If the polymerization is first started at a lower temperature and ends at a higher temperature, it is advisable to work with at least two initiators which disintegrate at different temperatures, namely firstly using an initiator which already decomposes at a lower temperature for the start of the polymerization and then complete the main polymerization with an initiator that decomposes at a higher temperature. Water-soluble and water-insoluble initiators or mixtures of water-soluble and water-insoluble initiators can be used. The water-insoluble initiators are then soluble in the organic phase. The initiators listed for this purpose can be used, for example, for the temperature ranges given below.

Temperature: 40 to 60 ° C:

0029Acetylcyclohexanesulfonyl peroxide, diacetyl peroxidicarbonate, dicyclohexyl peroxidicarbonate, di-2-ethylhexyl peroxidicarbonate, tert-butyl perneodecanoate, 2,2'-azobis- (4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis- (2-methyl-N- phenylpropionamidine) dihydrochloride, 2,2'-azobis- (2-methylpropionamidine) dihydrochloride.

Temperature: 60 to 80 ° C:

0030tert-butyl perpivalate, dioctanoyl peroxide, dilauroyl peroxide, 2,2'-azobis (2,4-dimethylvaleronitrile).

Temperature: 80 to 100 ° C:

0031Dibenzoyl peroxide, tert-butyl per-2-ethylhexanoate, tert-butyl permaleinate, 2,2'-azobis (isobutylronitrile), dimethyl 2,2'-azobisisobutyrate, sodium persulfate, potassium persulfate, ammonium persulfate.

Temperature: 100 to 120 ° C:

0032Bis- (tert-butyl peroxide) cyclohexane, tert-butyl peroxyisopropyl carbonate, tert-butyl peracetate, hydrogen peroxide.

Temperature: 120 to 140 ° C:

00332,2-bis (tert-butyl peroxy) butane, dicumyl peroxide, di-tert-amyl peroxide, di-tert-butyl peroxide.

Temperature:> 140 ° C

0034p-menthane hydroperoxide, pinane hydroperoxide, cumene hydroperoxide and tert-butyl hydroperoxide.

0035If, in addition to the initiators mentioned, salts or complexes of heavy metals, for example copper, cobalt, manganese, iron, vanadium, nickel and chromium salts or organic compounds such as benzoin, dimethylaniline or ascorbic acid, the half-lives of the specified radical-forming initiators can be reduced. For example, tert-butyl hydroperoxide with the addition of 5 ppm copper (II) acetylacetonate can be activated in such a way that polymerisation can take place at 100 ° C. The reducing component of redox catalysts can also be formed, for example, from compounds such as sodium sulfite, sodium bisulfite, sodium formaldehyde sulfoxylate and hydrazine. Based on the monomers used in the polymerization, 0.01 to 20, preferably 0.05 to 10,% by weight of a polymerization initiator or a mixture of several polymerization initiators is used. 0.01 to 15% of the reducing compounds are added as redox components. Heavy metals are used in the range of 0.1 to 100 ppm, preferably 0.5 to 10 ppm. It is often advantageous to use a combination of peroxide, reducing agent and heavy metal as a redox catalyst.

0036The copolymerization of the essential monomers (a) and (b) and the optionally used monomers (c) and / or (d) can also be carried out by the action of ultraviolet radiation, if appropriate in the presence of UV initiators. For the polymerization under the action of UV rays, the photo initiators or sensitizers that are usually suitable for this are used. These are, for example, compounds such as benzoin and benzoin ether, α-methylbenzoin or α-phenylbenzoin. So-called triplet sensitizers, such as benzyl diketals, can also be used. In addition to high-energy UV lamps, such as carbon arc lamps, mercury vapor lamps or xenon lamps, UV-low light sources, such as fluorescent tubes with a high proportion of blue, also serve as UV radiation sources.

0037In order to produce polymers with a low K value, the graft copolymerization is advantageously carried out in the presence of regulators. Suitable regulators are, for example, mercapto compounds, such as mercaptoethanol, mercaptopropanol, mercaptobutanol, mercaptoacetic acid, mercaptopropionic acid, butyl mercaptan and dodecyl mercaptan. Also suitable as regulators are allyl compounds, such as allyl alcohol, aldehydes, such as formaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde and isobutyraldehyde, formic acid, ammonium formate, propionic acid, hydrazine sulfate and butenols. If the polymerization is carried out in the presence of regulators, 0.05 to 20% by weight, based on the monomers used in the polymerization, are required.

0038In order to produce colorless or only slightly colored graft copolymers from components (A) and (B), the copolymerization is carried out in the presence of water-soluble phosphorus compounds in which the phosphorus has an oxidation number of 1 to 4, the water-soluble alkali metal or ammonium salts, water-soluble Compounds containing PO (OH) ₂ groups and / or their water-soluble salts. Phosphorous acid is preferably used. The phosphorus compounds in question are used to reduce the discoloration of the graft copolymers in amounts of from 0.01 to 5% by weight, based on the monomers (A) used. The phosphorus compounds in question are described in EP-A-0 175 317.

0039The copolymerization of components (A) and (B) is usually carried out in an inert gas atmosphere with the exclusion of atmospheric oxygen. Good mixing of the reactants is generally ensured during the polymerization. In the case of smaller batches in which a reliable removal of the heat of polymerization is ensured, the reactants, which are preferably present in an inert diluent, can be copolymerized discontinuously by heating the reaction mixture to the polymerization temperature. These temperatures are in the range of 40 to 150 ° C. With this method, however, graft copolymers are obtained which have a relatively high content of unpolymerized dicarboxylic acid. In order to be able to better control the course of the polymerization reaction, the monomers (A) are therefore added continuously or batchwise to the polymerizing mixture after the copolymerization has started, to the extent that the graft copolymerization is readily controllable in the desired temperature range. A type of addition of the monomers of component (A) is preferred in which the compounds of component (B) or at least some of the compounds of component (B) are initially introduced into the reactor and in it in the polymerization reactor together with at least one monomer (a) heated to the desired polymerization temperature with stirring. As soon as this temperature is reached, the monomers (b) and optionally (c) and / or (d) and the initiator and optionally a regulator are added over a period of about 1 to 10, preferably 2 to 8 hours. Such a procedure is used, for example, when polymerizing components (A) and (B) in an inert diluent in which component (B) is suspended and also in graft copolymerization carried out in solution.

0040The graft copolymers are preferably prepared by suspension or solution polymerization of components (A) and (B) in an aqueous medium, with solution polymerization in water being particularly preferred. In solution polymerization in an aqueous medium, the procedure is, for example, that the monomers (a) and at least some of the compounds of component (B) are initially introduced in an aqueous medium and the monomers (b) and, if appropriate, the monomers (c) and / or (d) continuously or batchwise added to the polymerizing reaction mixture and copolymerized in such a way that the degree of neutralization of the copolymerized monomer units (a) and (b) after completion of the graft copolymerization, ie when at least 95, preferably 98-99% of the monomers have polymerized, is 20 to 80%. The monomers (a) are preferably used in at least 20% neutralized form at the start of the polymerization. In the graft copolymerization in an aqueous medium, the entire amount of the compounds of component (B) or only a part, for example 50 Present% of the compounds of component (B) together with the monomers (a) and the remaining amounts of compounds of component (B) to the polymerizing reaction mixture together with the monomers (b) and, if appropriate, the monomers (c) and / or (d) add continuously or batchwise. To graft copolymers with low residual unpolymerized monomer (a), ie To obtain maleic acid in particular, it is important to control the degree of neutralization of the monomers during the copolymerization. It should be 20 to 80%, preferably 30 to 70%, during the graft copolymerization. For this purpose, for example, the monomers (a) and (b) can be partially neutralized so that their degree of neutralization is in each case in the range specified. However, it is also possible for the monomers of group (a) initially introduced in the reactor to be completely or approximately To neutralize 90% and to add the monomers of group (b) in non-neutralized form, so that the overall degree of neutralization of the monomers (a) and (b) and optionally (c), ie if one as (c) a monomer containing acid groups used, for example acrylamidopropanesulfonic acid or vinylphosphonic acid, during the polymerization from initially about 100% or about 90% to values ​​in the range from 20 to 80%. In order to maintain a certain degree of neutralization within this range of the monomers (a) and (b), a base, for example sodium hydroxide solution, potassium hydroxide solution, ammonia or ethanolamine, can be added during the copolymerization. Depending on the composition of the graft copolymers, the main amount, ie 60 to 80% of the monomers (a) and (b), is polymerized with a degree of neutralization of 20 to 80%. The solution copolymerization is particularly preferably carried out with hydrogen peroxide, sodium persulfate or mixtures in any ratio as initiator. This requires 0.5 to 20% by weight of initiator, based on the monomers (A). If the monomer mixtures (A) consist of a small proportion of the monomers of group (a), a relatively low amount of initiator and, for a high proportion of the monomers (a), a larger amount of initiator is used, for example at 90% by weight of monomer (a) about 15 to 18% by weight of initiator. Here too, the procedure is such that at least part of component (B) is initially introduced together with the monomers (a), which are preferably at least about 90% neutralized, and the monomers (b) and, if appropriate, the monomers (c) and / or (d) admits the required degree of neutralization of 20 to 80%. The degree of neutralization of the monomers (b) can be carried out either by adding appropriate amounts of base separately or by adding partially neutralized monomers (b) to the reaction mixture. The degree of neutralization of the partially neutralized monomers (b) is then in the range from 20 to 80%.

0041As already mentioned, polysaccharides in aqueous suspension can be subjected to the graft copolymerization. However, graft copolymers of polysaccharides are preferably prepared by first converting a water-insoluble polysaccharide in an aqueous suspension with the addition of enzymes and / or acids to a water-soluble form and subjecting the aqueous solution of the degraded polysaccharide to the graft copolymerization. Here, a water-insoluble polysaccharide, such as potato starch, is first suspended in water and broken down. This degradation can be carried out under the action of enzymes, for example α- or β-amylase or of debranching enzymes, for example pullulanase, or by the action of inorganic or organic acids in a known manner. Examples of suitable inorganic acids are phosphoric acid, sulfuric acid, hydrochloric acid and nitric acid. Suitable organic acids are, for example, saturated or unsaturated carboxylic acids, for example formic acid, acetic acid, propionic acid, acrylic acid, methacrylic acid, maleic acid, itaconic acid, p-toluenesulfonic acid and benzenesulfonic acid. The conversion of the polysaccharides into a water-soluble form is preferably carried out with a monomer (a), which is then used in the graft copolymerization. For example, potato starch or corn starch in aqueous suspension can be hydrolytically broken down in a temperature range from 50 to 150 ° C. by adding maleic acid or itaconic acid. As soon as the starch has reached the desired degree of degradation, the added maleic acid or itaconic acid is neutralized to at least 20, preferably 90%, and the graft copolymerization is carried out by adding the monomers (b) and optionally (c) and / or (d).

0042The enzymatic degradation of starch is carried out in the temperature range from 30 to 120 ° C, while the hydrolytic degradation of the starch is carried out at temperatures from 50 to 150 ° C. The hydrolytic degradation takes about 5 minutes to 10 hours, the degree of hydrolytic degradation of the starch depending on the selected temperature, pH and time. Further information on the breakdown of starch can be found in the specialist literature, cf. e.g. Günther Tegge, Starch and Starch Derivatives, Behr's Verlag, Hamburg 1984. In some cases it has proven advantageous to use at least one of the phosphorus compounds already according to the teaching of EP-A-0 175 317 in the enzymatic or hydrolytic degradation of the starch lead to polymers that are not or only very little colored.

0043In the graft copolymerization, the temperatures are usually in the range from 40 to 180, preferably 60 to 150 ° C. and in particular 70 to 110 ° C. As soon as the temperature in the copolymerization is above the boiling points of the inert diluent or solvent or the monomers, the copolymerization is carried out under pressure. The concentration of components (A) and (B) in the copolymerization in the presence of inert solvents or inert diluents is 10 to 80, preferably 20 to 70,% by weight. The graft copolymers can be prepared in the customary polymerization devices. For this purpose, for example, stirred kettles are used, which are equipped with an anchor, blade, impeller or multi-stage impulse countercurrent stirrer. In particular in the case of graft copolymerization in the absence of diluents, it can be advantageous to carry out the graft copolymerization in kneaders. It may also be necessary to polymerize in a kneader if you are working at high concentrations or if the natural products are high molecular weight and initially swell strongly.

0044Graft copolymers are obtained which, insofar as they are soluble in water, have K values ​​of 8 to 250, preferably 10 to 150 (measured on 1% strength aqueous solutions of the copolymers at pH 7 and 25 ° C.). The graft copolymers which can be prepared by the above-mentioned processes are colorless to brownish-colored products. When polymerizing in an aqueous medium, they are present as dispersions or polymer solutions. Depending on the particular composition of the graft copolymers, these are low-viscosity to pasty aqueous solutions or aqueous dispersions.

0045The high molecular weight graft copolymers, ie those with K values ​​from 120 to 250, are preferably used as thickeners for aqueous systems. Applications of this type are, for example, additions of the graft copolymers to paper coating slips in order to increase the viscosity and water retention of the paper coating slip, addition to aqueous paint dispersions and addition as a thickener in pigment printing pastes. Graft copolymers with a K value of 8 to 90, preferably 20 to 75, are used with particular advantage as additives for detergents and cleaning agents for textiles and hard surfaces in amounts of 0.1 to 20, preferably 0.5 to 12% by weight. based on the detergent formulation or detergent formulation. Graft copolymers of this K value range have an excellent incrustation-inhibiting effect in phosphate-free and low-phosphate (ie Phosphate contents below 25% by weight) detergents. Graft copolymers with K values ​​from 8 to about 35 can also be used as additives for detergents, such as those graft copolymers with K values ​​of at least 75. The low molecular weight graft copolymers additionally cause dispersion of the particle dirt in washing agents and prevent re-soiling of the items to be washed Textile goods. In addition, they often have a viscosity-reducing effect on detergent slurries. It is therefore often advantageous to use a mixture of graft copolymers with a higher K value and a low K value as a detergent additive. The high molecular weight graft copolymers act as thickeners in detergent formulations.

0046The graft copolymers with K values ​​from 8 to 90 are ideal as additives for dishwashing detergents. With additions of 0.1 to 20, preferably 0.5 to 12% by weight, they prevent deposits on dishes, cutlery and glassware.

0047The graft copolymers described above are biodegradable due to the natural substance content in the copolymer compared to the copolymers previously used based on ethylenically unsaturated monomers, but at least can be eliminated from the wastewater from sewage treatment plants with the sewage sludge. Particularly noteworthy is the fact that graft copolymers with a natural product content of about 40 wt 0 025 551 known as incrustation inhibitor in textile detergents highly effective copolymers of the monomers (a) and (b). In contrast to the graft copolymers described, mixtures of degraded starch, an oligosaccharide or monosaccharide and the copolymers of monomers (a) and (b), with a natural product content of approx. 40%, are significantly less effective as incrustation inhibitors when added to laundry detergents . The same applies to the graft polymers of acrylic acid onto polysaccharides or their degradation products known from the prior art mentioned at the outset.

0048The graft copolymers according to the invention can be used both in liquid and in powder detergents. Compared to the copolymers from the monomers of groups (a) and (b) known from EP-PS 0 025 551, they above all have improved compatibility in liquid detergent formulations.

0049The composition of detergent formulations can be very different. The same applies to the composition of detergent formulations. Detergent and cleaning agent formulations usually contain surfactants and optionally builders. This information applies to both liquid and powder detergent and cleaning agent formulations. Examples of the composition of detergent formulations which are common in Europe, the USA and Japan can be found, for example, in Chemical and Engn. News, volume 67, 35 (1989) tabulated.

0050The graft copolymers described above are used according to the invention in detergents which contain up to 45% by weight of phosphate, the use of the graft copolymers in detergents with a reduced phosphate content (which should be understood to mean a phosphate content of less than 25% by weight sodium triphosphate) or in phosphate-free ones Detergents and cleaning agents is preferred. The copolymers can be added to the detergent formulation in the form of granules, a paste, a highly viscous mass, as a dispersion or as a solution in a solvent. The graft copolymers can also be adsorbed on the surface of fillers, for example sodium sulfate or builders (zeolites or bentonites) and other solid auxiliaries in the detergent formulation.

0051Detergent formulations and detergent formulations are powdery or liquid. They can be composed differently regionally and according to the specific application.

0052Universal household detergents for drum washing machines, as are widespread in Europe, usually contain 5 to 10% by weight of anionic surfactants; 1 to 5% by weight of nonionic surfactants; 1 to 5% by weight of foam regulators, such as silicone oils or soaps; 0 to 40% by weight of softening agents, such as soda or pentasodium triphosphate, which can be partially or completely replaced by the compounds according to the invention; 0 to 30% by weight of ion exchanger, such as zeolite A; 2nd up to 7% by weight sodium silicates as corrosion inhibitors; 10 to 30% by weight of bleaches, such as sodium perborate, sodium percarbonate, organic peracids or their salts; 0 to 5% by weight of bleach activators, such as tetraacetylethylene diamine, pentaacetyl glucose, hexaacetyl sorbitol or acyloxybenzenesulfonate; Stabilizers, such as magnesium silicate or ethylenediaminetetraacetate; Graying inhibitors, such as carboxymethyl cellulose, methyl and hydroxyalkyl celluloses, polyglycols grafted with vinyl acetate, oligomeric and polymeric terephthalic acid / ethylene glycol / polyethylene glycol esters; Enzymes; optical brighteners; Fragrances; Plasticizers; Dyes and fillers.

0053In contrast to this, the heavy duty detergents used in the tub washing machines in the United States, Japan and these countries are mostly free of bleaching agents, their proportion of anionic surfactants is two to three times as high, they contain more washing alkalis, like soda and sodium silicates (usually up to 25% by weight) and mostly they also lack the bleach activators and bleach stabilizers. The content of surfactants and other ingredients can increase considerably if it is a matter of so-called detergent concentrates, which are sold on a retail basis without or without additives. Delicates and colored detergents, wool detergents and agents for manual washing also usually contain no bleach and low alkaline components with a correspondingly high proportion of surfactants.

0054Detergents for the commercial sector are tailored to the special conditions of industrial washing (soft water, continuous washing), which make it possible to focus on the type of laundry and the type of soiling. Combinations are therefore used in which one component predominates or others are completely absent, which are added separately if necessary. That is why the ingredients surfactants, builders (builders), alkalis and bleaches of these detergents vary within wide limits.

0055Suitable anionic surfactants for the abovementioned powder detergents are, for example, sodium alkylbenzenesulfonates, fatty alcohol sulfates and fatty alcohol polyglycol ether sulfates. Individual compounds of this type are, for example, C₈ to C₁₂ alkyl benzene sulfonates, C₁₂ to C₁₆ alkane sulfonates, C₁₂ to C₁₆ alkyl sulfates, C₁₂ to C₁₆ alkyl sulfosuccinates and sulfated ethoxylated C₁₂ to C₁₆ alkanols. Also suitable as anionic surfactants are sulfated fatty acid alkanolamines, α-sulfofatty acid esters, fatty acid monoglycerides or reaction products of 1 to 4 moles of ethylene oxide with primary or secondary fatty alcohols or alkylphenols. Other suitable anionic surfactants are fatty acid esters or fatty acid amides of hydroxy or amino carboxylic acids or sulfonic acids, such as, for example, the fatty acid sarcosides, glycolates, lactates, taurides or isothionates. The anionic surfactants can be in the form of the sodium, potassium and ammonium salts and also as soluble salts of organic bases, such as mono-, di- or triethanolamine or other substituted amines. The anionic surfactants also include the usual soaps, ie the alkali salts of the natural fatty acids.

0056Addition products of 3 to 40, preferably 4 to 20 moles of ethylene oxide with 1 mole of fatty alcohol, alkylphenol, fatty acid, fatty amine, fatty acid amide or alkanesulfonamide can be used as nonionic surfactants (nonionics), for example. The above-mentioned addition products of ethylene oxide can optionally contain up to 90% by weight, based on condensed ethylene oxide and propylene oxide, of condensed propylene oxide. The addition products which contain ethylene oxide and propylene oxide in condensed form can, if appropriate, be modified by condensing in butylene oxide in amounts of up to 60% by weight, based on the total alkylene oxide content. The addition products of 5 to 16 moles of ethylene oxide with coconut oil or tallow fatty alcohols, with oleyl alcohol or with synthetic alcohols with 8 to 18, preferably 12 to 18 carbon atoms, and with mono- or dialkylphenols with 6 to 14 carbon atoms in are particularly important the alkyl residues. In addition to these water-soluble nonionics, not completely water-soluble polyglycol ethers with 1 to 4 ethylene glycol ether residues in the molecule of interest, especially if they are used together with water-soluble nonionic or anionic surfactants.

0057Furthermore, the non-ionic surfactants that can be used are the water-soluble adducts of ethylene oxide with 20 to 250 ethylene glycol ether groups and 10 to 100 propylene glycol ether groups on polypropylene glycol ethers, alkylene diaminopolypropylene glycol and alkyl polypropylene glycols with 1 to 10 carbon atoms in the alkyl chain, in which the polypropylene glycol ether chain acts as a hydrophobic residue.

0058Nonionic surfactants of the amine oxide or sulfoxide type can also be used.

0059The foaming power of the surfactants can be increased or decreased by combining suitable types of surfactants. A reduction can also be achieved by adding non-surfactant-like organic substances.

0060Other constituents of the detergent mixture can also be monomeric, oligomeric and polymeric phosphonates, ether sulfonates based on unsaturated fatty alcohols, for example oleyl alcohol ethoxylate butyl ether and their alkali metal salts. These substances can, for example, with the help of the formula RO (CH₂CH₂O)_n-C₄H₈-SO₃Na, in which n = 5 to 40 and R = oleyl, are characterized.

0061The graft copolymers described above can also be used as an additive to liquid detergents. The liquid detergents contain, as a blending 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. If the graft copolymers are not directly miscible with the other components of the liquid detergent, it is possible to use a small amount of solubilizers, for example water or a water-miscible organic solvent, for example isopropanol, methanol, ethanol, glycol, diethylene glycol or triethylene glycol or corresponding propylene glycols, to be homogeneous Make mixtures. The amount of surfactant in liquid detergents is 4 to 50% by weight, based on the overall formulation, since the proportions of the constituents of liquid detergents vary widely depending on the regional market conditions or the intended use.

0062The liquid detergents can contain water in amounts of 10 to 60, preferably 20 to 50,% by weight. But they can also be anhydrous.

0063Anhydrous liquid detergents can also contain peroxo compounds for bleaching in suspended or dispersed form. Examples of peroxo compounds which may be mentioned are: sodium perborate, peroxocarboxylic acids and polymers with partially peroxo-containing groups. In addition, the liquid detergents can optionally contain hydrotropes. This includes compounds such as 1,2-propanediol, cumene sulfonate and toluene sulfonate. If such compounds are used to modify the liquid detergent, their amount, based on the total weight of the liquid detergent, is 2 to 5% by weight. In many cases, the addition of complexing agents has also proven to be advantageous for modifying powdery and liquid detergents. Complexing agents are, for example, ethylenediaminetetraacetic acid, nitrilotriacetate and isoserinediacetic acid and phosphonates, such as aminotrismethylenephosphonic acid, hydroxyethane diphosphonic acid, ethylenediaminetetraethylenephosphonic acid and their salts. The complexing agents are used in amounts of 0 to 10% by weight, based on the detergents. The detergents can also contain citrates, di- or triethanolamine, opacifiers, optical brighteners, enzymes, perfume oils and dyes. If they are used to modify the liquid detergents, these substances are present together in amounts of up to 5% by weight. The detergents are preferably free of phosphates. However, they can also contain phosphates, for example pentasodium triphosphate and / or tetrapotassium pyrophosphate. If phosphates are used, the proportion of the phosphates in the total formulation of the detergent is up to 45, preferably up to 25,% by weight.

0064The graft copolymers according to the invention can also produce synergistic effects with other known detergent additives (such as, for example, graying inhibitors, clay dispersants and substances which enhance the primary washing action, color transfer inhibitors, bleach activators) in powder and liquid detergents (phosphate-containing and phosphate-free), in which not only the graying inhibitor but also inhibition the effect of the other detergent additive can be enhanced.

0065In order to improve the properties of the graft copolymers according to the invention for use in detergents, it can be advantageous in some cases to subject the graft copolymers to an oxidative treatment subsequently. For this purpose, oxidizing agents are either allowed to act directly on the powdered graft copolymers or on suspensions of graft copolymers in an inert suspension medium or else on solutions of graft copolymers in an inert solvent, for example in a monohydric alcohol such as methanol, ethanol, n-propanol or isopropanol or preferably in water or in mixtures of water and alcohols. The oxidation is preferably carried out in aqueous solutions of the graft copolymers.

0066Suitable oxidizing agents are those which release oxygen when heated alone or in the presence of catalysts. Suitable organic compounds are generally peroxides which release active oxygen very easily. At low temperatures, only hydroperoxides and peracids have a clear oxidizing effect; peresters, diacyl peroxides and dialkyl peroxides only work at higher temperatures.

0067Suitable peroxides are, for example, diacetyl peroxide, isopropyl percarbonate, tert.-butyl hydroperoxide, cumene hydroperoxide, acetylacetone peroxide, methyl ethyl ketone peroxide, ditertiary butyl peroxide, dicumyl peroxide, tert.-butyl perpivalate, tert.-butyl peroctanoate, tert.-butyl perethyl. Preferred are the inexpensive inorganic oxidizing agents, which are particularly well suited for the oxidation of aqueous solutions of the polymers containing carbonyl groups. Examples include chlorine, bromine, iodine, nitric acid, sodium permanganate, potassium chlorate, sodium hypochlorite, sodium perborate, sodium percarbonate and sodium persulfate. A particularly preferred oxidizing agent is hydrogen peroxide. The decomposition of the per compounds, i.e. the oxidation, can be accelerated by the addition of accelerators or activators. These accelerators or activators are reducing but slightly electron-donating substances such as tert-amines, sulfinic acids, dithionites, sulfites, α- and β-ketocarboxylic acids, glucose derivatives and heavy metals, preferably in the form of soluble salts of inorganic or organic acids or complexes. Dimethylaniline, dimethyl-p-toluidine, diethylaniline, sodium dithionite, sodium sulfite, ascorbic acid, glucose, pentaacetylglucose, ferroammon sulfate, copper chloride, the acetylacetonates of iron, copper, cobalt, chromium, manganese, nickel and vanadium are particularly worth mentioning.

0068The oxidizing agents, calculated on the graft copolymers, are added in amounts of 1 to 50% by weight, preferably 5 to 30% by weight. The reducing agents, calculated on the oxidizing agents, are used in amounts of 2 to 50% by weight.

0069The heavy metal compounds, calculated as heavy metal and based on the polymers, are used in amounts of 0.1 to 100 ppm, preferably 0.5 to 10 ppm. It is often advantageous to accelerate the reaction, especially when working at low temperatures, to add both reducing agents and heavy metal compounds to the per compounds. The reaction temperatures can vary between 20 and 150 ° C, preferably 50 to 120 ° C. Sometimes it is also advantageous to accelerate the oxidation by irradiating it with UV light, or to oxidize it at low temperatures and for a short time, especially if only the -S groups contained in the graft copolymer are to be oxidized without the K -Value of the graft copolymer is markedly reduced. Air and oxygen can also be used alone or in combination with oxidizing agents for the oxidation of the graft copolymers.

0070In the treatment of the graft copolymers with oxidizing agents, graft copolymers with a relatively high K value, for example in the range from 160 to 200, are degraded to a relatively great extent, for example in the oxidative treatment of these graft copolymers, oxidized graft copolymers are obtained which have the K values ​​in the range from Have 15 to 60. In contrast, relatively low molecular weight graft copolymers, for example graft copolymers with K values ​​from 20 to 70, are degraded relatively slightly. The K value of the relatively low molecular weight, oxidatively treated graft copolymers is only slightly lower or in some cases even corresponds to the K values ​​of the untreated graft copolymers. The oxidatively treated graft copolymers have an improved calcium dispersing capacity compared to the untreated graft copolymers and moreover have an increased stability in washing and cleaning agents containing oxidizing agents.

0071The K values ​​of the polymers were determined according to H. Fikentscher, Cellulose-Chemie, Vol. 13, 58 to 64 and 71 to 74 (1932). K = kx 10³. The measurements were carried out on 1% aqueous solutions of the sodium salts of the graft copolymers at 25 ° C. and a pH of 7. Unless otherwise stated, the percentages are percentages by weight.

0072The DE values ​​of the starches or their derivatives mean dextrose equivalents. They were determined using the Luff-Schoorl method, cf. G. Tegge, Starch and Starch Derivatives, Behr's Verlag, Hamburg 1984, page 305.

Examples: Production of the graft copolymers

example 1

0073In a heatable reactor, which is provided with a stirrer, reflux condenser, thermometer, feed devices, nitrogen inlet and outlet devices, 263.1 g of water, 80 g of dextrin are white (90% soluble fraction), 63.8 g of maleic anhydride and 3.5 g of a 0.1% aqueous iron (II) ammonium sulfate solution and 94 g of 50% aqueous sodium hydroxide solution are heated to boiling. The degree of neutralization of the maleic acid formed from the maleic anhydride in aqueous solution is 90.2%. After the boiling of the reaction mixture has started, a solution of 178.2 g of acrylic acid in 141.9 g of water is added within 5 hours and a solution of 16.6 g of 50% hydrogen peroxide in 44.4 g of water is uniformly added within 6 hours Boil to. After the addition of acrylic acid has ended, the degree of neutralization of the maleic acid and acrylic acid units contained in the polymer is 31.1%. After the hydrogen peroxide metering has ended, the reaction mixture is heated to boiling for a further hour, then neutralized to a pH of 7.2 by adding 180 g of a 50% strength aqueous sodium hydroxide solution and cooled. A cloudy, highly viscous white solution with a solids content of 39.3% is obtained. The graft copolymer has a K value of 53 and a residual unpolymerized maleic acid content of 0.73%.

Example 2

0074Example 1 is repeated with the exception that instead of dextrin white, the same amount of maltodextrin with a DE value (according to Luff-Schoorl) of 11 to 14 is used. A cloudy, highly viscous yellowish solution with a solids content of 39.6% is obtained. The graft copolymer has a K value of 58.3 and contains 0.3% unpolymerized maleic acid.

Example 3

0075In the reactor given in Example 1, 263.1 g of water, 160 g of dextrose, 47.9 g of maleic anhydride, 3.5 g of a 0.1% iron (II) ammonium sulfate solution and 70.5 g of 50% aqueous sodium hydroxide solution Boiling heated. The degree of neutralization of the maleic acid formed from the maleic anhydride is 90.15%. Immediately after the start of boiling, a solution of 133.6 g of acrylic acid in 141.9 g of water is added within 5 hours and a solution of 12.45 g of 50% hydrogen peroxide in 44.4 g of water is uniformly boiled over 6 hours while the reaction mixture is boiling to. The degree of neutralization of the copolymerized maleic acid and acrylic acid units in the graft copolymer is then 31.1%. The reaction mixture is heated to boiling for a further 1 hour, then neutralized to a pH of 7.0 with 123.7 g of 50% strength aqueous sodium hydroxide solution and cooled. A clear, low-viscosity, brownish solution with a solids content of 37.5% is obtained. The graft copolymer has a K value of 26.4 and contains 0.24% unpolymerized maleic acid.

Example 4

0076Example 1 is repeated with the only exception that the same amount of potato starch is used instead of white dextrin. A cloudy, highly viscous white dispersion with a solids content of 39.4% is obtained. The residual monomer content of the graft copolymer of maleic acid is 1.8%. The K value cannot be determined because of the insolubility of the graft copolymer in water.

Example 5

0077In the reactor described in Example 1, 263.1 g of water, 120 g of dextrin are white (90% soluble fraction), 55.9 g of maleic anhydride, 3.5 g of 0.1% aqueous solution of iron (II) ammonium sulfate and 82 , 2 g of 50% aqueous sodium hydroxide solution and heated to boiling. The degree of neutralization of the maleic acid resulting from the maleic anhydride by hydrolysis is 90%. Immediately after the start of boiling, a solution of 155.9 g of 97% acrylic acid in 141.9 g of water is added within 5 hours and a solution of 14.5 g of 50% hydrogen peroxide in 44 is separated within 6 hours. 9 g of water are uniformly added and the reaction mixture is heated to boiling while stirring. The degree of neutralization of the maleic acid and acrylic acid units contained in copolymerized form in the copolymer is 31.7%. After the hydrogen peroxide addition has ended, the reaction mixture is heated to boiling for a further hour and then neutralized to a pH of 7 by adding 148 g of 50% strength sodium hydroxide solution. The cloudy, viscous, yellowish solution obtained has a solids content of 39.1%. The K value of the graft copolymer is 35 and the residual monomeric maleic acid content is 0.03%.

Example 6

0078The reactor described in Example 1 is 263.1 g of water, 160 g of maltodextrin with a DE value of 11 to 14, 47.9 g of maleic anhydride, 3.5 g of a 0.1% aqueous solution of iron (II) ammonium sulfate and 70.5 g of a 50% aqueous sodium hydroxide solution and heated to boiling. The degree of neutralization of maleic acid is 90.15%. Immediately after boiling begins, a solution of 133.6 g of 97% acrylic acid in 141.9 g of water is metered in within 5 hours and a solution of 12.45 g of 50% hydrogen peroxide in 44.4 g of water is metered in within 6 hours while maintaining the boiling of the mixture evenly. After the hydrogen peroxide addition has ended, the reaction mixture is heated to boiling for a further hour. The degree of neutralization of the maleic acid and acrylic acid units contained in the graft copolymer is 31.7%. 123.7 g of 50% strength aqueous sodium hydroxide solution are then added to a pH of 7. A clear, viscous brownish solution with a solids content of 39.7% is obtained. The graft copolymer has a K value of 37.9 and contains 0.09% of unpolymerized maleic acid.

Example 7

0079Example 6 is repeated with the exception that a dextrin of the Noredux type (Noredux E 200 from Cerestar) is used instead of maltodextrin. A clear, slightly viscous brownish solution with a solids content of 39.8% is obtained. The graft copolymer has a residual monomeric maleic acid content of 0.07% and has a K value of 35.7.

Example 8

0080235.4 g of maltodextrin with a DE value of 11 to 14, 230 g of water, 117.54 g of maleic anhydride and 173 g of 50% strength aqueous sodium hydroxide solution are placed in the reactor described in Example 1 and heated to boiling. The degree of neutralization of the resulting maleic acid is 90.1%. Immediately after the start of boiling, a solution of 139.2 g of 97% acrylic acid and 300 g of water is added within 5 hours, and solutions of 3.2 g of sodium persulfate in 80 g of water and 10.14 g of 30% are separately added within 6 hours. water peroxide in 60 g of water and polymerized at the boiling point of the reaction mixture. The maleic acid and acrylic acid units contained in the graft copolymer have a degree of neutralization of 50.6%. After the hydrogen peroxide addition has ended, the reaction mixture is heated to boiling for a further hour and neutralized by adding 137 g of 50% strength aqueous sodium hydroxide solution. A clear, viscous, brown solution with a solids content of 39% is obtained. The graft copolymer has a K value of 31.5 and contains 1.2% of monomeric maleic acid.

Example 9

0081298 g of water, 136 g of dextrose, 52.7 g of maleic anhydride, 3.5 g of a 0.1% strength aqueous solution of iron (II) ammonium sulfate and 77.5 g of 50% strength sodium hydroxide solution are placed in the reactor described in Example 1 and heated to boiling. The degree of neutralization of the maleic acid formed from the maleic anhydride by hydrolysis is 90.1%. Immediately after the start of boiling, 142.6 g of acrylic acid in 141.9 g of water are added over the course of 5 hours, and 13.7 g of 50% hydrogen peroxide in 44.4 g of water are separately added within 6 hours, and the polymerization is carried out at the boiling point of Mixed by. The degree of neutralization of the maleic acid and acrylic acid units contained in the graft copolymer is 31.7%. After the hydrogen peroxide addition has ended, the reaction mixture is heated to boiling for a further hour and then adjusted to a pH of 7 using 136 g of 50% strength aqueous sodium hydroxide solution. The clear, slightly viscous brown solution thus obtained has a solids content of 35%. The graft copolymer has a K value of 27 and contains 0.03% residual maleic acid.

Example 10

0082400 g of water, 320 g of dextrose, 16 g of maleic anhydride, 3.5 g of 0.1% strength aqueous solution of iron (II) ammonium sulfate and 23.5 g of 50% strength aqueous sodium hydroxide solution are placed in the reactor described in Example 1 and added to Boiling heated. The degree of neutralization of the resulting maleic acid is 90%. Immediately after the start of boiling, 43.21 g of acrylic acid in 141.9 g of water are metered in over the course of 5 hours, and a solution of 4.15 g of 50% strength hydrogen peroxide in 44.4 g of water is boiled separately within 6 hours. The reaction mixture is then heated to boiling for a further 1 hour. The degree of neutralization of the maleic acid and acrylic acid units contained in the copolymer is 31.7%. After the end of the polymerization, 20 g of 50% strength aqueous sodium hydroxide solution are added, giving a clear, slightly viscous, brown solution with a solids content of 37.5% and a pH of 7. The graft copolymer has a K value of 14 , 4 and contains 0.13% residual maleic acid.

Example 11

0083263.1 g of water, 194 g of potato starch (82.4% strength), 23.95 g of maleic anhydride and 0.57 g of phosphorous acid are placed in the reactor specified in Example 1, heated to boiling and stirred under reflux for 1 hour. Then 23.95 g of maleic anhydride and 70.5 g of 50% aqueous sodium hydroxide solution are added to the template, so that a partially neutralized maleic acid with a degree of neutralization of 90.15% is present in the template. A solution of 133.6 g of acrylic acid and 141.9 g of water is added to the boiling reaction mixture in the course of 5 hours, and a solution of 12.45 g of 50% strength hydrogen peroxide in 44.4 g of water is uniformly added over the course of 6 hours. The degree of neutralization of the copolymerized maleic acid and acrylic acid units in the copolymer is 31.7%. After the initiator addition has ended, the reaction mixture is heated to boiling for a further 1 hour and then neutralized to a pH of 7 with 125 g of 50% strength aqueous sodium hydroxide solution. The slightly cloudy, slightly viscous, light brown solution has a solids content of 41%. The graft copolymer has a K value of 24.8 and contains less than 0.01% of unpolymerized maleic acid.

Example 12

0084384.1 g of water, 291 g of potato starch (82.4% strength), 32 g of maleic anhydride and 0.75 g of phosphorous acid are placed in the reactor described in Example 1 and heated to boiling for 1 hour. Then 47 g of 50% strength aqueous sodium hydroxide solution are added so that 90% of the maleic acid formed from the maleic anhydride is neutralized. Immediately after the sodium hydroxide solution has been added to the boiling mixture, a solution of 89.1 g of acrylic acid and 71 g of water is added, also under boiling conditions, within 5 hours and, separately, a solution of 4.98 g of 50% hydrogen peroxide within 6 hours 22.2 g of water metered in evenly. The reaction mixture is then stirred at the boiling point for a further 1 hour. The degree of neutralization of the maleic acid and acrylic acid units contained in the graft copolymer is 31.1%. After the end of the polymerization, 108 g of 50% strength aqueous sodium hydroxide solution are added to a pH of 7. A cloudy, viscous light brown solution with a solids content of 38.5% is obtained. The graft copolymer has a K value of 24.1 and contains 1.4% unpolymerized maleic acid.

Examples 13-22

0085In the reactor described in Example 1, water, natural product, 47.9 g of maleic anhydride, 0.57 g of phosphorous acid and 2 g of sodium hydrogen sulfite are placed in a reactor and stirred at 80 ° C. for 1 hour in a stream of nitrogen. Then 70.5 g of 50% aqueous sodium hydroxide solution are slowly added to the initial charge. The degree of neutralization of the maleic acid is then 90.15%. A solution of 133.6 g of acrylic acid in 141.9 g of water is then added over a period of 5 hours at a temperature of 80 ° C., and solutions of 5.7 g of 50% hydrogen peroxide in 40 g of water are added separately within 6 hours and 2.85 g sodium persulfate in 40 g water. The reaction mixture is then reheated for a further 2 hours. The degree of neutralization of the maleic acid and acrylic acid units contained in the copolymers is 31.13%. The amounts for water and natural product as well as the data of the polymer solutions are given in Table 1. The natural substances used in Examples 13, 15, 16 and 17 are saccharification products (maltodextrins and glucose syrups) which contain the following components:<tables id="tabl0001" num="0001"><img file="EP0441197A2_D0003.tif" /></tables><tables id="tabl0002" num="0002"><img file="EP0441197A2_D0004.tif" /></tables>

Example 24

0086248.9 g of maltodextrin with a DE value of 11 to 14, 543.5 g of water, 75.75 g of maleic anhydride and 111.3 g of 50% sodium hydroxide solution are placed in the reactor described in Example 1 and heated to boiling. The degree of neutralization of the resulting maleic acid is 90%. Immediately after the start of boiling, a mixture of 89.7 g of acrylic acid, 119.63 g of hydroxypropyl acrylate (isomer mixture) and 106.65 g of water and, separately therefrom, solutions of 9.98 g of 30% hydrogen peroxide are added within 5 hours 60 g of water and 6 g of sodium persulfate in 69 g of water are uniformly added and polymerize when the mixture is boiled. After the initiator has been added, the reaction mixture is heated to boiling for a further 1 hour. The degree of neutralization of the polymerized maleic acid and acrylic acid units is 49.8%. After completion of the copolymerization, 92 g of 50% strength aqueous sodium hydroxide solution are added up to a pH of 7. The clear, brownish, viscous solution thus obtained has a solids content of 38.5%. The graft copolymer has a K value of 33 and contains 1.1% unpolymerized maleic acid.

Example 25

0087290 g of maltodextrin with a DE value of 11 to 14, 470 g of water, 4.2 ml of 0.1% strength aqueous solution of iron (II) ammonium sulfate, 101.38 g of maleic anhydride and 74 are in the reactor specified in Example 1 , 52 g of sodium hydroxide and heated to boiling. The degree of neutralization of the resulting maleic acid is 90%. Immediately after the start of boiling, a mixture of 120 g of acrylic acid and 114.4 g of a 58% aqueous solution of the sodium salt of acrylamidomethylpropanesulfonic acid is added within 5 hours, and 80 g of 30% hydrogen peroxide and a solution of 24 g of sodium persulfate in 72 are added within 6 hours g of water evenly and polymerizes at the boiling point of the mixture. After the initiator addition has ended, the reaction mixture is heated to boiling for a further hour. The degree of neutralization of the acid groups is 53.5%. After the end of the polymerization, the reaction mixture is neutralized by adding 155 g of 50% strength aqueous sodium hydroxide solution. A clear brown solution with a solids content of 42.3% is obtained. The graft copolymer has a K value of 27.6 and a residual monomeric maleic acid content of 0.01%.

Example 26

0088A graft copolymer solution prepared according to Example 2 is heated to boiling. 131 g of 30% hydrogen peroxide are evenly metered into the boiling mixture over the course of 8 hours. A clear, yellow viscous solution with a solids content of 38% is obtained. The K value of the copolymer is 32.

Examples 27 to 34

0089231.4 g of water, 323 g of the 80% aqueous solution of a maltodextrin with a DE value of 30, 77.1 g of maleic anhydride, 0.91 g of phosphorous acid, 3.04 g of sodium disulfite, 4.24 g of 0.1% aqueous iron (II) ammonium sulfate solution heated to 55 ° C in a gentle stream of nitrogen. Now 113.4 g of 50% sodium hydroxide solution are metered in over the course of 15 minutes and the temperature is increased to 85.degree. A monomer mixture of the composition described in Table 2 is then metered in uniformly in 5 hours and a solution of 30.4 g of 30% strength hydrogen peroxide in 50 g of water is metered in uniformly in 6 hours at 85 ° C. in a weak nitrogen atom. The mixture is then heated for a further 1 hour at 85 ° C., cooled and neutralized with 50% sodium hydroxide solution to a pH of approx. 7.

0090The appearance, solids content and pH of the polymer solution and the K values ​​of the graft copolymers obtained are also given in Table 2.<tables id="tabl0003" num="0003"><img file="EP0441197A2_D0005.tif" /></tables><tables id="tabl0004" num="0004"><img file="EP0441197A2_D0006.tif" /></tables>

Example 35

0091In a reactor according to Example 1, 154.5 g of water, 316 g of hydroxypropyl potato starch, 80% strength (viscosity in 10% strength aqueous solution at 20 ° C. 100 mPas), 74.2 g of maleic anhydride, 0.88 g of phosphorous acid and 2. 93 g of sodium disulfite heated to 55 ° C. in a weak nitrogen atom. After reaching 50 ° C, 109 g of 50% sodium hydroxide solution are metered in and at the same time the temperature is increased to 80 ° C. Now within 5 hours a solution of 204.9 g acrylic acid and 180 g water and within 6 hours a solution of 8.78 g 50% hydrogen peroxide in 46 g water and a solution of 4.39 g sodium persulfate in 57.6 g water 80 ° C metered in the weak nitrogen atom. The mixture is then heated for a further 1 hour at 80 ° C., cooled and neutralized to a pH of 6.8 with 50% sodium hydroxide solution and then diluted with 230 g of water. The clear, almost colorless, highly viscous solution obtained has a solids content of 41.1% and the K value of the polymer is 81.9.

Examples 36 to 39

0092In a reactor according to Example 1, 154.5 g of water, 316 g of maltodextrin with a DE value of 40, 74.2 g of maleic anhydride, 0.88 g of phosphorous acid and 2.53 g of sodium disulfite are heated to 55 ° C. in a weak nitrogen atom. After this temperature has been reached, the mixture is neutralized with 109 g of 50% sodium hydroxide solution and the temperature is raised to 80.degree. A solution of 204.9 g of acrylic acid and 180 g of water is then added within 5 hours and within 6 hours. an initiator solution, as listed in the following Table No. 3, evenly metered in at 80 ° C in a weak stream of nitrogen. The mixture is then reheated at 80 ° C. for 1 hour, cooled and neutralized to a pH of 7 with 50% sodium hydroxide solution and diluted with 230 g of water. Appearance, solids content and K value can be seen from Table 3.<tables id="tabl0005" num="0005"><img file="EP0441197A2_D0007.tif" /></tables>

Comparative examples

Comparative Example 1 (according to JP-A-12350/87)

0093In the reactor specified in Example 1, 34 g of dextrose and 400 g of water are heated to a temperature of 80 ° C. for 1 hour under a nitrogen atmosphere. The reaction mixture is then cooled to 30 ° C. 66 g of acrylic acid, 0.005 g of L-ascorbic acid and 0.05 g of 30% hydrogen peroxide are added and the mixture is polymerized at a temperature of 40 ° C. within 4 hours. After completion of the polymerization, the pH is adjusted to 7 by adding 30% aqueous sodium hydroxide solution. A highly viscous, cloudy solution with a solids content of 18% is obtained. The K value of the polymer is 172.

Comparative Example 2

0094265.6 g of maltodextrin with a DE value of 11 to 14, 398.4 g of water and 1.8 g of phosphorous acid are placed in the reactor described in Example 1 and heated to 95 ° C. in a stream of nitrogen. 294.6 g of acrylic acid and a solution of 13.2 g of 2-mercaptoethanol in 55 g of water are added within 4 hours, and a solution of 2.94 g of sodium persulfate in 70 g of water at 95 is separated over the course of 4.5 hours ° C evenly. After the initiator has been added, the reaction mixture is heated at 95 ° C. for 1 hour. Then, with the aid of steam distillation, the mercaptoethanol not incorporated into the graft polymer is removed. The reaction mixture is then neutralized to a pH of 7 by adding 335 g of 50% strength aqueous sodium hydroxide solution. The light brown, cloudy solution has a solids content of 37.3%. The copolymer has a K value of 22.9.

Comparative Example 3

009580 g of the 40% aqueous solution of the sodium salt of a copolymer of 70% by weight acrylic acid and 30% by weight maleic acid with a K value of 60 are mixed well with 20 g of a 40% solution of dextrin white. The mixture is tested as an additive to detergents.

Comparative Example 4

009670 g of the 40% aqueous solution of the sodium salt of a copolymer of 70% by weight acrylic acid and 30% by weight maleic acid with a K value of 60 are mixed well with 30 g of a 40% solution of dextrin white.

Comparative Example 5

009760 g of a 40% aqueous solution of the sodium salt of a copolymer of 70% by weight acrylic acid and 30% by weight maleic acid with a K value of 60 are mixed with 40 g of a 40% solution of a dextrin of the Noredux type (Noredux E 200 from Fa. Cerestar) well mixed.

Comparative Example 6

009860 g of a 40% aqueous solution of the sodium salt of a copolymer of 70% by weight acrylic acid and 30% by weight maleic acid with a K value of 60 are mixed with 40 g of a 40% solution of dextrose.

Comparative Example 7

009960 g of a 40% aqueous solution of the sodium salt of a copolymer of 70% by weight acrylic acid and 30% by weight maleic acid with a K value of 60 are mixed well with 40 g of a 40% suspension of potato starch.

Comparative Example 8

0100A 40% solution of the sodium salt of a copolymer of 70% by weight acrylic acid and 30% by weight maleic acid with a K value of 60 is tested as an additive to detergent formulations.

Application engineering examples

0101In order to test the incrustation-inhibiting effect of the graft copolymers described above, the polymers were each incorporated into two different powder detergents A and B. Test fabrics made of cotton fabric were washed with these detergent formulations. The number of wash cycles was 10. After each cycle, the fabric was ironed dry. After this number of washes, the ash content of the fabric was determined by ashing the test fabric in each case. The more effective the polymer contained in the detergent is, the lower the ash content of the test fabric and the higher the percentage activity indicated, ie 0% effectiveness means the achievable ash content or incrustation without additive in the detergent formulation. 100 % Effectiveness means that the incrustation inhibitor completely prevents deposition. A negative effect or an effect that is less than zero means that the substance has an incrustation-promoting property. This is equivalent to the fact that the ash content with polymer addition is higher than without polymer addition.

0102The following formula is used to calculate the effectiveness "W" from the ash contents.<chemistry id="chem0003" num="0003"><img file="EP0441197A2_D0008.tif" /></chemistry>

0103After the 10 wash cycles, the cotton fabric showed an ash content of 4.14% when using detergent A and 2.33% when using detergent B.<tables id="tabl0006" num="0006"><img file="EP0441197A2_D0009.tif" /></tables><tables id="tabl0007" num="0007"><img file="EP0441197A2_D0010.tif" /></tables>

0104The graft copolymers 22 to 39, when tested for incrustation inhibition in detergent B analogously to Examples 40 to 58, gave effects of 59 to 77%. These values ​​are thus clearly above the effects of the compounds tested as incrustation inhibitors in Comparative Examples 1 to 7.<tables id="tabl0008" num="0008"><img file="EP0441197A2_D0011.tif" /></tables>

0105The application results with respect to incrustation inhibition show that the polymers according to the invention in Table 2 have a significantly greater effect than the graft polymers in Table 3 according to the prior art (Comparative Examples 1 and 2).

0106A comparison of the physical mixtures of natural product and commercial copolymer (this copolymer is a highly effective incrustation inhibitor according to EP-B-0025551) (cf. comparative examples 3 to 7) with the polymers 1, 3, 5, 7, 11 according to the invention shows that the inventive Graft copolymers are significantly more effective than the corresponding mixtures.

0107If one compares the graft copolymers according to the invention with a commercial copolymer (comparative example 8), it is surprisingly found that the polymers according to the invention are partially better, in particular in the ecologically promising phosphate-free detergent formulation, despite the high proportion of natural substances.

0108This effect is particularly surprising since the presence of the carboxyl-free or low-carboxyl group natural substance reduces the proportion of carboxyl groups in the graft copolymers according to the invention particularly strongly in comparison to the pure copolymer (comparative example 8) composed of acrylic acid and maleic acid.

0109The biodegradation according to Zahn-Wellens (DIN 38 142, part 24, static test (L 25)) was investigated on the graft copolymer according to Example 5 in comparison to the copolymer of Comparative Example 8. The decrease in carbon after different times is shown in Table 4.<tables id="tabl0009" num="0009"><img file="EP0441197A2_D0012.tif" /></tables>

0110While the copolymer according to comparative example 8 clearly shows elimination from the sewage sludge, the graft copolymer according to the invention according to example 5 can at least partially conclude that it is biodegradable.

Examples 59 to 63

0111The incrustation-inhibiting effect of the graft copolymer prepared according to Example 17 was investigated in the presence of bleach activators in accordance with the above-mentioned specification. First, the bleach activators listed in Table 5 were each added in an amount of 3% to detergent B described above and the ash content was determined without the addition of polymer. For the determination of the ash content with polymer, bleach activators indicated in Table 5 were added in an amount of 3% to detergent B and, in addition, in each case 3% of the graft copolymer prepared according to Example 17 in the form of the Na salt. As stated above, the effectiveness "W" was calculated from the two series of measurements for the ash contents. These values ​​are given in Table 5.

Table 5

0112Incrustation inhibition of the Na salt of the graft copolymer prepared according to Example 17 in the presence of bleach activators in detergent B.<tables id="tabl0010" num="0010"><img file="EP0441197A2_D0013.tif" /></tables>

0113A comparison of the activities from Table 5 with the copolymer according to Comparative Example 8 (see Table 3) shows that the graft copolymer prepared according to Example 17 in combination with bleach activators is a very good incrustation inhibitor.

0114The graft copolymers described above also show very good incrustation inhibition in the presence of other detergent additives, such as, for example, complexing agents, graying inhibitors or dispersants. Table 6 shows the results of examples in which the graft copolymer prepared according to Example 17 in the form of the Na salt in the presence of various other detergent additives (referred to as additive in Table 6) in detergent B was tested for its incrustation-inhibiting effect. The composition of the detergent formulation of Examples 64 to 69 can be found in Table 6.<tables id="tabl0011" num="0011"><img file="EP0441197A2_D0014.tif" /></tables> ISDA = isoserine diacetic acid Na salt NTA = nitrilotriacetate Na salt Homopolyacrylic acid sodium salt with a K value of 30 Graft copolymer PEO / VAc = graft polymer of vinyl acetate on polyethylene oxide with a molecular weight (number average) of 6000 g / mol in a weight ratio of 1.6: 1 according to US Pat. No. 4,746,456 oligoester = oligoester from tetraphthalic acid / ethylene glycol / PEO with a molecular weight (number average) = 1500 g / mol in a weight ratio of 19.4: 3.5: 77.1.

0115In addition, other builders and / or cobuilders and combinations with one another can be used. Zeolites, bentonite, crosslinked polycarboxylates of acrylic acid, maleic acid and other unsaturated carboxylic acids or dicarboxylic acids, hydroximono (di, tri) carboxylic acids, for example citric acid or tartaric acid, are to be mentioned in this connection.