WO1993013192A1

WO1993013192A1 - Polycondensation products of butane tetracarboxylic acid and polyhydroxy compounds, and their use in washing and cleaning agents

Info

Publication number: WO1993013192A1
Application number: PCT/EP1992/002848
Authority: WO
Inventors: Dieter Boeckh; Heinrich Hartmann; Elisabeth Kappes; Alfred Oftring; Richard Baur; Alexander Kud; Volker Schwendemann
Original assignee: Basf Aktiengesellschaft
Priority date: 1991-12-20
Filing date: 1992-12-10
Publication date: 1993-07-08
Also published as: DE4142131A1

Abstract

Described are polycondensation products obtained by condensing (a) butane-1,2,3,4-tetracarboxylic acid, optionally mixed with hydroxycarboxylic acids or other carboxylic acids, with (b) polyhydroxy compounds selected from the group comprising mono-, oligo- and polysaccharides, reduced mono- and oligosaccharides and their amino derivatives, oxidized mono-, oligo- and polysaccharides, alkyl polyglycosides, polyvinyl alcohols and oligoglycerins with more than 2 glycerin units, or mixtures thereof, plus, optionally, (c) up to 20 mole %, relative to component a, of alkylene glycols, polyalkylene glycols or monohydric C4-C20 alcohols, in the ratio, by weight, of a:b from 50:1 to 0.5:1, the condensation products produced having a K-value of 8 to 100 (determined by the H. Fikent method in a 2 % by wt. aqueous solution at 25 °C and pH 7 on the Na salts of the condensation products). The invention also concerns the use of the polycondensation products as additives to low-phosphate or phosphate-free washing or cleaning agents in amounts ranging from 0.1 to 30 % by wt. relative to the agent.

Description

Polycondensates from butane tetracarboxylic acid and polyhydroxy compounds and their use in detergents and cleaning agents

description

The invention relates to polycondensates of butane tetracarboxylic acid, which can optionally be partially replaced by other carboxylic acids, with polyhydroxy compounds from the group of mono-, oligo- and polysaccharides, reduced mono- or oligosaccharides and their amino derivatives, sugar carboxylic acids, polyvinyl alcohols, oligoglycerols or mixtures thereof and optionally Glycols, polyalkylene glycols or alkoxylated alcohols and the use of the polycondensates as an additive to low-phosphate or phosphate-free washing and cleaning agents.

From DE-B-2 147 778, detergents and cleaning agents are known which have water-soluble salts of acidic carboxylic acid esters from at least trihydric aliphatic or olefinically unsaturated carboxylic acids or hydroxycarboxylic acids and at least trihydric aliphatic alcohols as builders, with each hydroxyl group containing Alcohol is a molecule of carboxylic acid bound. Typical examples of such esters are glycerol tricitrate, sorbitol hexacitrate and pentaerythritol tetracitrate. These citric acid esters are readily biodegradable, act as builders in detergents and cleaners and form stable dispersions in the wash liquor with hydrophilic pigment particles.

From DE-B-1 617 122 washing and cleaning agents are known which contain 0.1 to 20% by weight, based on the total weight of the agent, of water-soluble salts of free carboxyl groups containing polyesters are characterized, the acid esters of tricarboxylic acids and / or tetracarboxylic acids and their alcohol residues derived from dihydric alcohols. Suitable polyesters of this type are, for example, polyesters from citric acid and ethylene glycol. The polyesters described have a graying-inhibiting effect in washing liquors and prevent the re-accumulation of dirt particles from the washing liquor on the textile goods to be washed.

From JP-A-58/91775, aqueous paints are known which contain reaction products from polycarboxylic acids, such as citric acid, isocitric acid, tricarballylic acid or butanetetracarboxylic acid, and polyols, such as, for example, glycerol, diglycerin, pentaerythritol, ethylene glycol or polyethylene glycol, as binders ¬ th. EP-A-0 433 010 discloses polycarboxylates which can be obtained by esterification of citric acid, isocitric acid or propane tricarboxylic acid with glycol, glycerol, erythritol, pentaerythritol, mono-, oligo- and polysaccharides as well as polyvinyl alcohol or polyallyl alcohol. Polyvinyl citrate and polyallyl citrate are emphasized as preferred compounds. The polycarboxylates are used as builders in detergent formulations.

The object of the present invention is to produce new substances which are suitable as detergent additives.

The object is achieved according to the invention with polycondensates of butanetetracarboxylic acid and polyhydroxy compounds which are obtainable by condensation of

a) butane-l, 2,3,4-tetracarboxylic acid, which can be replaced by up to 70 mol% with mono- or dibasic hydroxycarboxylic acids or up to 49 mol% with other two- to four-basic aliphatic carboxylic acids,

b) polyhydroxy compounds from the group of mono-, oligo- and polysaccharides, reduced mono- or oligosaccharides and their amino derivatives, oxidized mono-, oligo- or polysaccharides, alkyl (poly) glycosides, polyvinyl alcohols, oligoglycerols with more than 2 glycerol units or their mixtures

and if necessary

c) up to 20 mol%, based on component a), of C ₂ - to C ₁ -alkylene glycols, polyalkylene glycols with a molar mass of up to 2000 or monovalent C - to C o-alcohols optionally alkoxylated with up to 50 mol of alkylene oxide.

in the weight ratio a): b) from 50: 1 to 0.5: 1 to condensation products with a K value of 8 to 100 (determined according to H. Fikentscher in 2% by weight aqueous solution at 25 ° C and pH 7 on the Na salt of the condensation products).

The polycondensates are used as additives to low-phosphate or phosphate-free washing and cleaning agents in amounts of 0.1 to 30% by weight, based on the agent.

Component a) is preferably butane-1,2,3,4-racarboxylic acid. However, butanetetracarboxylic acid can be used in a mixture with 1- or 2-basic hydroxycarboxylic acids and / or other 1- to 4-basic aliphatic carboxylic acids in the polycondensation. Suitable 1- or 2-basic hydroxycarboxylic acid Ren are for example glycolic acid, lactic acid, malic acid and tartaric acid. This group of acids can replace up to 70 mol% of butane tetracarboxylic acid as component a). Suitable other di- to 4-basic aliphatic carboxylic acids are, for example, succinic acid, adipic acid, citric acid, oxalic acid, alkenyl succinic acids, alkyl succinic acids, aconitic acid, tricarballyl acid. This group of carboxylic acids can replace up to 49 mol- ^'* of butane tetracarboxylic acid as component a) in the polycondensation. In addition to the butanetetracarboxylic acid, the mono- or dianhydride or the mono- or diesters with C - to C ₄ -alcohols of this carboxylic acid can also be used in the condensation.

To produce the polycondensates, component b) comprises polyhydroxy compounds from the group of the mono-, oligo- and polysaccharides, the reduced mono- or oligosaccharides and their amino derivatives, oxidized mono-, oligo- or polysaccharides, alkyl (poly ) glycosides, polyvinyl alcohols, oligoglycerols with more than 2 glycerol units or mixtures thereof. Individual compounds from the group of the monosaccharides are, for example, glucose, manose and fructose, from the group of the oligosaccharides, sucrose, lactose, leucrose, isomaltulose, cellulose, maltose, glucose syrups and dextrins are mentioned as examples. Examples of polysaccharides are starch, degraded starches, acidic, enzymatically or thermally degraded starches, oxidized starches, etherified starches such as carboxymethyl starch, hydroxypropyl starch, cellulose, methyl cellulose, hydroxymethyl cellulose, carboxymethyl cellulose, inulin, chitin, chitosan, pectins and Alginate. Individual compounds from the group of reduced sugars and their aminated derivatives are, for example, sorbitol, mannitol, xylitol, inositol and aminosorbitol. Examples of suitable sugar carboxylic acids are gluconic acid, glucaric acid, glucoheptonic acid, alginic acid, sucrose mono-, di- and tricarboxylic acids. Suitable compounds b) are also alkyl glycosides and alkyl polyglycosides. The alkyl group can contain 1-20, preferably 1-4 and 8-16, particularly preferably 12-14, carbon atoms. Examples include methyl glucoside, butyl glucoside or the substance class of alkyl polyglycosides, as described in EP-A-0 357 696. The alkyl group can be saturated or unsaturated, branched or unbranched. The alkyl group can also be substituted, for example carry a hydroxyl group. Suitable compounds of this type are, for example, hydroxyethyl glucoside and hydroxypropyl glucoside and the corresponding polyglucosides. The polyglucosides contain an average of 1.1 to 10, preferably 1.3 to 3, glucoside units. Suitable oligoglycerols contain 3 to 10 glycerol units. These compounds arise, for example, from the condensation of glycerol in the presence of alkali or acid. Suitable oligoglycerols are, for example, triglycerol, tetraglycerol, pentaglycerol and hexaglycerol as well as polymers which have up to 10 glycerol units in the molecule.

Polyvinyl alcohols are also suitable as component b), all water-soluble polyvinyl alcohols being suitable. They generally have viscosities of 3 to 10,000, preferably 10 to 5,000, mPas (determined in a 10% strength aqueous solution at 20 ° C. using a Höppler ball falling viscometer in accordance with DIN 53 015). The polyvinyl alcohols are usually produced by hydrolysis of polyvinyl acetate. They can be used in partially or completely hydrolyzed form in the preparation of the polycondensates according to the invention. The molar masses of the polyvinyl alcohols are up to 100,000 and preferably up to 25,000. It is also possible to use oxidatively degraded polyvinyl alcohols as component (b). Such degraded polyvinyl alcohols have molecular weights in the range from approximately 500 to 50,000. The molecular weights of the polyvinyl alcohols are preferably 1,000 to 10,000. The degree of hydrolysis of the polyvinyl alcohols produced from polyvinyl acetate is generally 50 to 100, preferably 85 up to 99%.

Component b) is preferably sorbitol, mannitol, methyl glucoside, gluconic acid, polyvinyl alcohols with molecular weights up to 15,000 and oligoglycerols with 3 to 10 glycerol units.

Component c) can optionally contain up to 20 mol%, based on component a), of C ₂ -C ₄ -alkylene glycols, polyalkylene glycols with a molar mass of up to 2,000 or monovalent, if appropriate with up to 50 mols Alkylene oxide alkylated C ₄ - to C *; o-alcohols are used. Examples of individual compounds of component c) are ethylene glycol, propylene glycol, 1,4-butanediol, polyethylene glycols and polypropylene glycols with molar masses of up to 2,000, block copolymers of ethylene oxide and propylene oxide with molar masses of up to 2,000, butanol, lauryl alcohol or Stearyl alcohol.

The polycondensates are produced by condensing components a) and b). This creates polyester. The condensation is carried out to such an extent that condensation products with a K value of 8 to 100, preferably 10 to 60, (determined according to H. Fikentscher in 2% strength by weight aqueous solution at 25 ° C. and pH 7 on sodium hydroxide) salting of the condensation products). The condensation can be carried out in inert organic solvents or in a melt the reactants are carried out. Which method is the most suitable depends on the nature of component b). Insoluble polysaccharides b) are preferably used in the finest possible form. When condensing in the absence of inert organic solvents, it is advantageous to dissolve the polyhydroxy compounds, in particular if these cannot be melted without decomposition, in a sufficient amount of water or to convert them into a finely divided aqueous dispersion. In order to dissolve or stably disperse component b), it is often necessary to heat the water-containing solution to temperatures up to 100 ° C. In the case of condensation, it can also be advantageous if the carboxylic acids to be used as component a) are neutralized up to a proportion of 30%.

For example, an aqueous solution of components a) and b) can be partially neutralized by adding sodium hydroxide solution or another base such as potassium hydroxide solution or ammonia, ethanolamine, triethanolamine, diethanolamine, morpholine or alkylamines. To produce the polyesters, the water is then largely distilled off at temperatures from 50 to 120 ° C., and the temperature of the reaction mixture is then increased to 100 to 220, preferably 120 to 170 ° C. The process variant in which one assumes a water-containing melt of the reaction participants and the water is distilled off at temperatures of 120 to 220 ° C. is preferred. In this variant of the process, the butanetetracarboxylic acid is used in a stoichiometric amount compared to the polyhydroxy compounds, in particular if they have higher molar masses, in order to avoid crosslinking of the polyesters.

In the case of high molecular weight polyhydroxy compounds, in particular polyvinyl alcohols or polysaccharides, the viscosity of the water-containing melt increases so much that it can no longer be mixed in stirred kettles. In order to lower the viscosity during the condensation, one adds to the highly viscous one

Melt a diluent and continue the condensation reaction. Suitable diluents are, for example, monobasic aliphatic carboxylic acids, such as formic acid, acetic acid, propionic acid, lauric acid, palmitic acid, stearic acid, coconut fatty acid, tallow fatty acid, oleic acid and mixtures thereof.

If the boiling point of the fatty acids used as diluent is below the condensation temperature, the condensation is carried out under increased pressure. This is especially the case when using formic acid, acetic acid and propionic acid. The readily volatile monobasic aliphatic carboxylic acids serve both as diluents and as entraining agents for the water formed during condensation. The difficultly volatile carboxylic acids, which are used to lower the viscosity, can remain in the condensation product.

In the condensation, viscous melts are obtained, some of which become solid as conversion progresses or when they cool to room temperature. The condensation is preferably carried out in an inert gas stream or under reduced pressure. If the condensation of components a), b) and optionally c) is carried out in an inert organic solvent, it is preferably carried out in suspension. For example, the compounds which are suitable as component a) can be introduced into the reactor together with the inert solvent and, if appropriate, a protective colloid, and components b) can be added batchwise or continuously and by boiling under reflux and distilling off the water formed in the reaction the reaction mixture are condensed. Suitable organic solvents are, for example, toluene, o-, m- and p-xylene, mesitylene, Cu ol, higher-boiling aliphatic hydrocarbon (boiling range from 120 to 160 ° C.) and mixtures of these solvents. The abovementioned solvents can also be used with polar aprotic solvents. agents such as ethylene glycol dimethyl ether, diethylene glycol diethyl ether, dioxane and / or cyclohexanone are used. In some cases it can be advantageous to carry out the condensation in the presence of protective colloids which then disperse the condensate formed and prevent the formation of a viscous mass which solidifies after cooling. Suitable protective colloids are, for example, alkylated polyhydric C ₂ to Ca alcohols, such as the reaction products of 3 to 35 mol of ethylene oxide and / or propylene oxide with glycerol, oligoglycerol or pentaerythritol. The protective colloids can additionally contain Cg to C ₂₂ alkyl groups bonded via ether, ester or amide bonds. The amount of protective colloid in the condensation is 0.05 to 5% by weight, based on the polyester. If an inert organic solvent is used in the condensation, the concentration of the solids, ie the polyester formed, in the inert diluent is 10 to 70, preferably 20 to 65% by weight.

Control of the progress of the reaction in the esterification can be determined in all process variants by determining the amount of water distilled off from the reaction mixture. Since the acid number and the viscosity of the reaction mixture also change during the esterification, the course of the esterification can be checked by determining these measurands on samples taken from the reaction mixture. The esterification of components a), b) and optionally c) is preferably carried out in the melt in the absence of catalysts. However, the use of customary acidic catalysts, which are usually used in esterification reactions, is possible. The condensation in the melt can be carried out in the usual flasks or kettles, each of which is equipped with a stirrer. In many cases, however, it is more advantageous to carry out the condensation reaction in a reactor which has a more powerful mechanical mixing device than a vessel provided with a conventional stirrer. For example, an evacuable kneading reactor with a vertical or horizontal shaft, inert gas supply and distillation device is particularly suitable. Other suitable reactors are, for example, condensation extrusion reactors which allow melt condensation in a first reaction zone by distilling off the water of reaction and in which the melt is then extruded in a shaping zone. The extruded strands are distributed or pulverized into a lumpy reaction product.

Components a) and b) are used in the condensation in a weight ratio of 50: 1 to 0.5: 1, preferably 10: 1 to 1: 1. When using polyvinyl alcohol or polysaccharides as component (b), the weight ratio of components (a): (b) in the condensation is preferably 40: 1 to 4: 1. The production of polycondensates by condensation of a) butane-1,2,3,4-tetracarboxylic acid as the sole component a) with b) sorbitol, mannitol, gluconic acid, methylglucoside, oligoglycerol with 3-10 is particularly preferred Glycerol units, polyvinyl alcohol or mixtures thereof with a): b) weight ratio of 10: 1 to 1: 1. Portions of component a) used with stoichiometry favor the process of condensation in the melt. They can remain in the product as monomers or oligomers or can be partially or completely separated from the polycondensate by ultrafiltration, extraction or precipitation. The degree of esterification of the hydroxyl groups of the polyhydroxy compounds of component b) is at least 10, preferably 15 to 100%. The polyester carboxylates obtainable in this way are biodegradable. For example, over 85% of the reaction product of sorbitol with 6 mol of butane tetracarboxylic acid is degraded within 28 days (determined according to the Zahn-Wellens test, static test according to DIN 38 412, part 24.

The polycarboxylates can be used in the acid form or in partially neutralized form, if component a) has been partially neutralized during the manufacture of the products, directly after use. But you can also completely neutralize. The salts of the polycondensates are obtained by customary neutralization with bases such as sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide, sodium, potassium, lithium, calcium, ammonium carbonate or hydrogen carbonate, ammonium hydroxide, ethanolamine, diethanolamine or trietha - nolamine. The bases are preferably used as aqueous solutions for neutralization. Neutralization with sodium hydroxide solution is preferred. Soda or sodium bicarbonate carried out, the pH being monitored continuously so that the polyester hydrolysis is as low as possible. In order to store the polyesters obtained in the condensation without modification by hydrolysis, they can be isolated from the neutralized aqueous solution, preferably in the form of the neutral sodium salt. Freeze drying, spray drying or spray fluidized bed drying of the aqueous solutions is suitable for this. The aqueous solution can be dried without further additives or with a mixture with washing-active substances.

The polycondensates described above are used as additives in low-phosphate or phosphate-free detergents and cleaning agents. gene from 0.1 to 30 wt .-%, based on the washing and cleaning agents used. Low-phosphate detergents are understood to mean those formulations which contain no more than 25% by weight of phosphate, calculated as sodium triphosphate. The polyesters are preferably used in amounts of 0.5 to 15% by weight, based on the detergent or cleaning agent formulation.

The polycondensates in the detergent fleet have good dispersibility for particle dirt, especially for clay minerals (clay). This property is important because loamy dirt from textile goods is widespread. The polyesters are builders for detergents and reduce the incrustation and graying on the washed fabric during the washing process. They are therefore also suitable as incrustation and graying inhibitors.

The composition of the washing and cleaning formulations can be very different. Detergents and cleaning agents usually contain 2 to 50% by weight of surfactants and optionally builders. This information applies to both liquid and powder detergents. 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, Vol. 67, 35 (1989) tabulated. Further information on the composition of detergents and cleaners can be found in WO-A-90 13581 and Ulimann's Encyclopedia of Industrial Chemistry, Verlag Chemie, Weinhein 1983, 4th edition, Pages 63-160 are taken. Also of interest are detergent formulations which contain up to 60% by weight of an alkali silicate and up to 10% by weight of a polycondensation product according to the invention. Examples of suitable alkali silicates are the 5 amorphous sodium disilicates which are described in EP-A-0 444 41, and crystalline sheet silicates which, according to EP-A-0 337 219, are contained in detergent formulations as builders and according to EP -B-0 164 514 are used for softening water, and sodium silicates, which are obtainable by dewatering 10 sodium silicate solutions and drying to water contents of 15 to 23, preferably 18 to 20% by weight.

If necessary, detergents can also contain a bleaching agent, e.g. Sodium perborate, which in case of its use in quantity

15 to 30 wt .-% can be contained in the detergent formulation. The detergents and cleaning agents can optionally contain further conventional additives, e.g. Complexing agents, citrates, opacifiers, optical brighteners, enzymes, perfume oils, color transfer inhibitors, graying inhibitors and / or lead actives

20 fathers.

The K values of the polyesters were determined according to H. Fikentscher, Cellulose Chemie, Vol. 13, 58 to 64 and 71 to 74 (1932) in an aqueous solution at a temperature of 25 ° C. and a concentration of 25 2% by weight. determined at pH 7 on the sodium salt of the polyester. The percentages in the examples mean% by weight.

example 1

30.3 g of butane-1,2,3,4-tetracarboxylic acid were placed in a 100 ml glass reactor equipped with a stirrer, a distillation bridge, a dropping funnel and a device for supplying inert gas and melted by heating to a temperature of 200 ° C. Once the temperature of

35 200 ° C was reached, a solution of 9.1 g of sorbitol in 20.9 g of water was added to the melt within 30 minutes. The water distilled off from the reaction mixture. After the addition of the aqueous sorbitol solution had ended, the reaction mixture was stirred for a further 30 minutes in a gentle stream of inert gas at 200 ° C.

40 densifies. After cooling, a brittle solid product was obtained, which was dissolved in water, neutralized with sodium hydroxide solution and freeze-dried. The polyester thus obtained had a K value of 11.7.

45 Example 2

In the apparatus described in Example 1, 70.3 g of butanetetracarboxylic acid were mixed with 10.9 g of sorbitol and the mixture was heated to a temperature of 200 ° C. with stirring. The melt was then condensed in a nitrogen atmosphere at a temperature of 200 ° C. for 30 minutes. After the reaction mixture had cooled, a brittle solid product was obtained, which was dissolved in water and neutralized with sodium hydroxide solution. The polyester thus obtained had a K value of 13.8.

Example 3

8.8 g of 84,000 (M _w ) molecular weight polyvinyl alcohol were dissolved in 79.2 g of boiling water. An aqueous solution of 46.8 g of 1,2-butane, 2,3,4-tetracarboxylic acid in 46.8 g of water was added to the boiling solution with stirring. The mixture was heated from 100 to 200 ° C. while stirring and distilling off water, a partial esterification of the polyvinyl alcohol occurring. After distilling off 127 g of water, the reaction product became solid. The reaction mixture was then cooled to room temperature and adjusted to a pH of 7 by adding aqueous sodium carbonate solution. The neutralized solution was then largely freed of unreacted butanetetracarboxylic acid by ultrafiltration on a membrane with an exclusion limit of 10,000 D and then freeze-dried. The polyester thus obtained has a K value of 38.7.

Example 4

234 g of butanetetracarboxylic acid were introduced with 8.8 g of polyvinyl alcohol (M _w 3000), 35.2 g of water and 100 g of acetic acid in a 2 1 reactor equipped with a stirrer and distillation bridge, and the water / acetic acid azeotrope was added 160 ° C (bath temperature) distilled. After 2 h, a further 580 g of acetic acid were metered in and distilled within 3 h until the boiling temperature of the pure acetic acid was reached. The remaining acetic acid was largely distilled off in vacuo (10 mbar), the batch was suspended in water and neutralized with NaOH. The solution was filtered in order to separate small amounts of insoluble constituents and then worked up further as in Example 3. The product shows a K value of 24.3. Example 5

196 g of a 50% aqueous solution of gluconic acid and 118.1 g of butane-1,2,3,4-tetracarboxylic acid are mixed together and 5 by heating to a temperature in the range of 140 to

170 ° C melted. At the same time, 107 g of water are distilled off. The condensate still contains approx. 2% free butanetetracarboxylic acid and 1% free gluconic acid. It is dissolved in water and adjusted to pH 6.5 by adding aqueous sodium hydroxide solution. 10 The polyaddition product has a K value of 18.2.

Example 6

39.2 g of a 50% aqueous solution of gluconic acid and 118.1 g of 15 butanetetracarboxylic acid are mixed and melted. By heating the reaction mixture to a temperature in the range from 140 to 170 ° C., the components are condensed with one another and 28.5 g of water are distilled off. The condensate still contains about 2.9% unreacted butanetetracarboxylic acid and about 1.8% 20 free gluconic acid. After cooling, the condensation product is dissolved in water, adjusted to a pH of 6.5 by adding a 20% aqueous sodium carbonate solution, and the sodium salt of the condensation product is isolated by concentrating the aqueous solution in vacuo. The K value of the polyester is 13.8. 25

Example 7

Oligoglycerin / butanetetracarboxylic acid

30 24 g of a polyglycerol with an average degree of polymerization of n = 3.1 (OH number = 1150 mg KOH / g) and 117 g of butanetetracarbonic acid in 43.2 g of water are melted and heated to 140 ° to 170 ° C. Distilled 51 g of water. The reaction product is then dissolved in water by adding a

35 20% sodium carbonate solution adjusted to pH 6.5 and the sodium salt dried by concentration in vacuo. The polyaddition product has a K value of 15.3.

Example 8

40 methyl glucoside / butanetetracarboxylic acid

141.9 g of butanetetracarboxylic acid are heated with 231 g of water and treated with 48 g of 50% strength aqueous NaOH and 28.95 g of α-methylglucoside. With stirring, 255 g of water are separated off as described in Example 6. After dissolving in water, adding aqueous sodium hydroxide solution until pH 6.5 is reached while cooling to <10 ° C and drying gives the corresponding sodium salt as a powder with a K value of 14.2.

Example 9

468.9 g of butanetetracarboxylic acid were heated to 100 ° C. while stirring with 64.8 g of wheat starch in 127 g of water, and 127 g of glacial acetic acid were added after 15 minutes. The water / acetic acid azeotrope was distilled off at 160 ^° C. (bath temperature). At the same time, a further 90 g of acetic acid were metered in and distilled within 5.5 h until the boiling point of the pure acetic acid was reached. The remaining acetic acid was largely distilled off in vacuo (10 mbar), the batch was suspended in water and neutralized with NaOH. Undissolved portions were filtered off and the solution freeze-dried. The product has a K value of 28.6.

Application engineering examples

Clay dispersion

The removal of particle dirt from tissue surfaces is supported by the addition of polyelectrolytes. The stabilization of the dispersion resulting from the detachment of the particles from the tissue surface is an important task of these polyelectrolytes. The stabilizing influence of the anionic dispersants results from the fact that, owing to the adsorption of dispersant molecules on the solid surface, their surface charge is increased and the repulsive energy is increased. Other factors influencing the stability of a dispersion include steric effects, temperature, pH value and the electrolyte concentration.

With the clay dispersion test (CD test) described below, the dispersibility of various polyelectrolytes can be assessed in a simple manner.

CD test

Finely ground china clay SPS 151 is used as a model for particulate dirt. 1 g of clay is intensively dispersed in a standing cylinder (100 ml) for 10 minutes with the addition of 1 ml of a 0.1% sodium salt solution of the polyelectrolyte in 98 ml of water. Immediately after stirring, a 2.5 ml sample is taken from the center of the standing cylinder and, after dilution to 25 ml, the turbidity of the dispersion is determined using a turbidimeter. After the dispersion has stood for 30 or 60 minutes, samples are taken again and the turbidity determined as above. The turbidity of the dispersion is specified in NTU (nephelometric turbidity units). The less the dispersion settles during storage, the higher the measured turbidity values and the more stable the dispersion. The dispersion constant, which describes the temporal behavior of the sedimentation process, is determined as the second physical measured variable. Since the sedimentation process can be approximately described by a mono-potential time law, τ indicates the time in which the turbidity drops to 1 / e-th of the initial state at time t = 0.

The higher a value for τ, the slower the dispersion settles.

The measured values show that the polycondensates according to the invention are good dispersants for clay.

Primary washing ability test

The clay detachability of textile fabrics was specifically investigated using washing tests. Clay minerals are colored and, when deposited on the fabric, give it a color veil. In order to determine the influence of the polycondensates on the primary washing action, a fabric soiled with clay was produced by mixing cotton / polyester fabric with a clay mixture consisting of 33.3% each of the types 178 / R (ocher), 262 (brown) and 84 / rf (red-brown) from Carl Jäger, Hilgert, evenly coated. The types of clay are different "bold"; ie they differ in the content of aluminum, iron and manganese oxide. The clay mixture was homogeneously applied to the tissue in the form of a 20% suspension in deionized water with vigorous pumping around the suspension. This was done with a jigger from Küsters, Krefeld, at 10 meters / min using BW / PES ² fabric (33/67, from Winkler, Waldshut). After 3 runs, 600 1 of completely deionized water were then rinsed once. The wet fabric was then dried in a tenter at 50 ° C. and a drying speed of 2 meters / min. The clay fabric produced in this way contains 1.76% clay, determined by ashing at 700 ° C, 2.5 h.

The washing tests were carried out under the following conditions:

Washing machine: Launder-o-meter

Number of washing cycles: 1 Number of rinsing cycles: 1 Number of washing attempts: 6 Washing temperature: 20-24 C Washing time: 15 min. Fleet quantity: 500 g VE ¹ 'water + 80 ppm ethoxylated oxo alcohol (C13.15-oxa alcohol + 8 EO)

Water hardness (Ca ²⁺ + Mg ²⁺ ): 1 mmol / 1

MoI ratio 3: 1: 6 Ca ²⁺ : Mg ^{2 *} * -: HC0 ₃ -: pH: 10 + 0.1

Test concentration of the 80 ppm polymer:

Dirt tissue: 5 g clay tissue

White fabric or clean fabric: 5 g PES / BW ² 'fabric - VE = completely desalinated ^{2 *} PES / BW = polyester / cotton

After rinsing, the fabric is spun and the fabrics are hung up to dry individually. The fabric is measured with an Elrepho 2000 from Data Color, Heidenheim, namely 6 measuring points per piece of fabric. The wavelength range used for the evaluation is 420-700 nm. The reflectance is measured as a function of the wavelength. Barium sulfate serves as a reference. According to W. Baumann, R. Broßmann, BT Groebel, N. Kleinemeier, M. Krayer, AT Leaver and H.-P. Oesch; Melliand Textilberichte 67 (1986), 562 ff. Calculated the color strength without weighting the eye irritation function. The primary wash efficiency in% is calculated using the following equation: (fs.b - fs, a) /(fs.b -Ξ, O '' 100

fs, _b = color strength of the soiled fabric (clay fabric) before washing.

f _{s, a} = color strength of the soiled fabric after washing.

f _s . _o = color strength of the clean fabric before soiling (dirty fabric before soiling).

The use of the color strength for calculating the primary washing effect has the advantage in comparison to the reflectance at a wavelength or the K / S values used in the literature (K = absorption coefficient and S = scattering coefficient) at one wavelength that the visible range of the spectrum is recorded and dirt particles of all colors are taken into account.

Washing tests with the claimed compounds show the following results:

The table shows that by adding the claimed compounds, the primary washing action is higher than without addition. These compounds thus positively support the washing effect.

Claims

1. Polycondensates from butanetetracarboxylic acid and polyhydroxy compounds which are obtainable by condensation of

a) butane-1,2,3,4-tetracarboxylic acid, up to 70 mol% by mono- or dibasic hydroxycarboxylic acids or up to

49 mol% can be replaced by other two- to four-basic aliphatic carboxylic acids,

b) polyhydroxy compounds from the group of mono-, oligo- and polysaccharides, reduced mono- or oligosaccharides and their amino derivatives, oxidized mono-, oligo- or polysaccharides, alkyl (poly) glycosides, polyvinyl alcohols, oligoglycerols with more as 2 glycerol or their mixtures

and if necessary

c) up to 20 mol%, based on component a)

C ₂ to C ₄ alkylene glycols, polyalkylene glycols with a molecular weight of up to 2000 or monovalent C ₄ to C ₂ alcohols which are alkoxylated with up to 50 mol of alkylene oxide.

in the weight ratio a): b) from 50: 1 to 0.5: 1 to condensation products with a K value of 8 to 100 (determined according to H. Fikentscher in 2% by weight aqueous solution at 25 = C and pH 7 on the Na salt of the condensation products).

2. Polycondensates according to claim 1, characterized in that they are obtainable by condensation of

a) Butane-1,2,3,4-tetracarboxylic acid

With

b) sorbitol, mannitol, gluconic acid, methyl glucoside, oligoglycerol with 3 - 10 glycerol units, polyvinyl alcohol or mixtures thereof

in the weight ratio a): b) from 10: 1 to 1: 1.

3. Use of the polycondensates according to claims 1 and 2 as an additive to low-phosphate or phosphate-free detergents and cleaning agents in amounts of 0.1 to 30% by weight, based on the agent.