WO1999003960A2

WO1999003960A2 - Use of polyelectrolytes as sequestering agents

Info

Publication number: WO1999003960A2
Application number: PCT/EP1998/004243
Authority: WO
Inventors: Jaume Josa; Bernd Fabry
Original assignee: Henkel Kommanditgesellschaft Auf Aktien
Priority date: 1997-07-17
Filing date: 1998-07-08
Publication date: 1999-01-28
Also published as: DE19730650C2; DE19730650A1; ES2370113T3; PL338184A1; ATE521688T1; HUP0002896A3; EP0998547B1; HUP0002896A2; SK552000A3; WO1999003960A3; EP0998547A2

Abstract

The invention relates to the use of a polyelectrolytes as sequestering agents for producing aqueous bleaching agents. According to the invention, it is possible to obtain preparations which protect the fabric from yellowing, preferably chlorine bleaching solutions, especially together with buffers and chlorine-resistant tensides.

Description

Use of polyelectrolytes as sequestering agents

Field of the Invention

The invention relates to the use of the polyelectrolytes as sequestering agents for the production of aqueous bleaching agents.

State of the art

While heavily soiled textiles are used in many European countries to use powdered or liquid heavy-duty detergents that only reach their performance at higher temperatures, cold washing, for example, is preferred by consumers in the United States and Spain, where it is particularly difficult to remove a detergent and remove it Stains a liquid bleach, preferably based on hypochlorite.

A large number of liquid bleaching agents are known from the prior art. For example, EP-A 0274885 (ICI) recommends the use of mixtures of linear and branched amine oxides for the production of viscous hypochlorite bleaches. According to the teaching of EP-A 0145084 (Uni-lever), mixtures of amine oxides with soaps, sarcosinates, taurides or sugar esters can also be used for this purpose. From the documents EP-A 0137551 and EP-A 0447261 (Unilever) the use of amine oxides with soap or sarcosinate and other anionic surfactants, for example alkyl sulfates, alkyl ether sulfates, secondary alkane sulfonates or alkyl benzene sulfonates as a thickening component for hypochlorite solutions, is known. From EP-A1 0447261 aqueous bleaching compositions containing sodium hypochlorite and anionic surfactants are also known. However, the hypochlorite concentration of these agents is 0.1 to 8% by weight of active chlorine. In German patent DE-C1 4333100, the applicant finally proposed chlorine bleaching solutions based on hypochlorites, fatty alcohol ether sulfates, amine oxides and amine oxide phosphonic acids. The use of silicates or carbonates as buffers in chlorine bleaching liquors can be found, for example, in documents US 4,623,476 (Procter & Gamble) and EP-A1 0079102 and EP-A1 0137551 (Unilever). High demands are placed on bleaches of the type mentioned by the consumer: they must be compatible with textiles, ie the stains must be removed by treatment with the aggressive chemical hypochlorite without attacking the fabric. Since skin contact with the bleaching agents is not excluded, the preparations must also be as dermatologically compatible as possible. A particular problem is that hypochlorite solutions also attack metals and the dissolved metal traces can be deposited on the textile fibers during washing, which is ultimately reflected in the yellowing of the fabric. While market players are trying to prevent this redeposition by using silicates, in practice this measure does not always prove to be satisfactory.

Accordingly, the complex object of the invention was to counteract the yellowing of the laundry by the influence of heavy metal ions and to provide sequestering agents which allow the production of aqueous bleaching agents, in particular chlorine bleaching liquors, which are chlorine-stable, gentle on textiles and as skin-friendly as possible have a sufficiently high viscosity and reliably prevent the deposition of metal traces on the fabric if the stain removal capacity is high.

Description of the invention

The invention relates to the use of polyelectrolytes as sequestering agents for the production of aqueous bleaching agents.

Surprisingly, it was found that the addition of small amounts of polyelectrolytes to aqueous bleaching agents, in particular to hypochlorite solutions, significantly reduces the deposition of metals on the fabric during washing and counteracts the yellowing of the fibers. The invention includes the knowledge that the use of buffers such as in particular silicates, carbonates and / or phosphonates and optionally mild, chlorine-stable surfactants such as preferably alkyl ether sulfates, amine oxides, alkyl and / or alkenyl oligoglycosides and fatty acid salts to further improve the stabilization against yellowing, cleaning performance and dermatological compatibility. Finally, the agents according to the invention have a sufficiently high viscosity so that metering by the consumer is possible without problems. Polyelectrolytes

(a) Low molecular weight dicarboxylic acids. In the simplest case, low molecular weight dicarboxylic acids which follow the formula (I) can be used as polyelectrolytes

RiOOC (CH ₂ ) nOOCR ² (I)

in which R ¹ and R ^{2 represent} hydrogen, an alkali metal and / or alkaline earth metal, ammonium, alkyammonium, alkanolammonium or glucammonium and n represents numbers from 0 to 64. Typical examples are oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid and the dimer and trimer fatty acids based on unsaturated fatty acids, namely oleic acid, elaidic acid, gadoleic acid and erucic acid. The dicarboxylic acids can be mono- or polyunsaturated and / or have an aromatic ring instead of the alkylene groups. Typical examples are maleic acid, fumaric acid, sorbic acid, phthalic acid and terephthalic acid. Neutralization takes place when the acids mentioned are introduced into the alkaline bleaching agents. However, they can also be used directly in the form of their salts, preferably as sodium salts. The use of adipic acid or sodium adipate as the polyelectrolyte is particularly preferred.

(b) Low molecular weight polyvalent hydroxycarboxylic acids. Typical examples of suitable polyvalent hydroxycarboxylic acids are malic acid, tartaric acid and in particular citric acid. These acids can also be used in the form of their alkali and / or alkaline earth metal, ammonium, alkylammonium, alkanolammonium or glucammonium salts. The use of citric acid or sodium citrate as the polyelectrolyte is particularly preferred.

(c) Mono- and copolymers of unsaturated monocarboxylic acids and their esters. Suitable monomers follow the formula (II)

CH ₂ = CR3 (CH ₂ ) mCOOR ⁴ (II)

in which R ^{3 represents} hydrogen or a methyl group, R ^{4 represents} hydrogen or a linear or branched hydrocarbon radical having 1 to 22, preferably 2 to 12 and in particular 3 to 8 carbon atoms and m represents 0 or numbers from 1 to 10. Typical examples are acrylic acid and / or methacrylic acid and their esters with methanol, ethanol, propanol, isopropyl alcohol, n-butanol, isobutanol, sec-butanol, tert-butanol, pentanol, capro alcohol, caprylic alcohol, 2-ethylhexyl alcohol, capric alcohol, lauryl alcohol, Isotridecyl alcohol, myristyl alcohol, cetyl alcohol, palm oleyl alcohol, stearyl alcohol, isostearyl alcohol, oleyl alcohol, elaidyl alcohol, petroselinyl alcohol, linolyl alcohol, linolenyl alcohol, elaeostearyl alcohol, arachyl alcohol, gadoleyl alcohol, behenylalcohol alcohol, erucyl alcohol and brassidyl alcohol and their technical mixtures, which are obtained, for example, from high-pressure hydrogenation of technical methyl esters based on fats and oils or aldehydes from Roelen's oxosynthesis. Homopolymers or copolymers of acrylic acid, methacrylic acid and their methyl, tert-butyl or 2-ethylhexyl esters are preferably used. The resulting polymers can have average molecular weights of the order of 300 to 5,000,000, preferably 10,000 to 1,000,000, preferably 50,000 to 500,000 and particularly preferably 100,000 to 250,000 daltons. This distribution of preferred molecular weights also applies to the following groups of suitable polymeric sequestering agents. Typical examples of suitable homopolymers and copolymers of acrylic and methacrylic acid with a molecular weight in the range from 5,000 to 15,000 daltons are given in German Auslegeschrift DE-OS 1808824 (Grace). Polymers which are prepared in the presence of sulfur compounds such as, for example, thioglycolic acid or 2-mercaptoethanol are also particularly suitable [cf. US 3665035 and US 3787488 (Magna)]. The homopolymers and copolymers which are prepared by the process of DE-AS 2632773 (Ciba) are also suitable. The thioether groups formed during the polymerization are then oxidized to sulfoxide and / or sulfone groups. Suitable sulfur-containing acrylic acid / acrylic acid ester polymers with hydrophobic components are also the subject of US 4008164 (Nalco). Polymers containing hydroxyl groups can also be used, which are produced, for example, by copolymerizing acrylic acid with acrolein and subsequent disproportionation [cf. DE-AS 2522637], from US 3682224 (Bleyle) copolymers of methacrylic acid with vinylsulfonic acid are also known in this connection. Other suitable polyacrylates or polymethacrylates are described in the following publications: GB-A1 1034680 (Commonwealth Scientific), NL-A 7400160 (Grace), BE-A 620771 (cyanamide) and US 3516916 (Grace).

(d) Homo- and copolymers of unsaturated dicarboxylic acids and their derivatives. Unsaturated dicarboxylic acids that can be used as monomers have already been mentioned under (a). However, maleic anhydride is preferably used because of its high reactivity and low price. The products that can be produced, for example, by hydrolysis of polymaleic anhydride have a high charge intensity. Ring structures, which arise during the polymerization as a result of side reactions, also give the molecules a certain chain stiffness, which has an advantageous effect on the sequesteration. Polymaleic anhydrides (PMSA) with molecular weights in the range from 300 to 5000 daltons are known, for example, from US 3810835 (Ciba). Copolymers of PMSA and poly (meth) acrylic acid with molecular weights in the range from 1,000 to 50,000 are mentioned in DE-AS 2412926 (Ciba). The subject of US 3650970 (Atlantic Richfield) are copolymers of maleic anhydride and styrene which are subjected to ring opening with polyethylene glycol (molecular weight 300 to 1,000) and also show a good sequestering effect. The same applies to copolymers of maleic anhydride with sulfonated styrene [FR-A 2322831 (Betz)], vinyl acetate [US 3755264 (Amicon)], methacrylic acid / styrene [US 4065607 (Pfitzner)], allyl acetate [US 4001134 (Grace)] and / or acrolein [DE-AS 2404192 (Ciba)].

(e) Homo- and copolymers of unsaturated monocarboxamides and their derivatives. In the

These substances are preferably compounds which are produced either by (co) polymerizing the monomers or by polymer-analogous hydrolysis of poly (meth) acrylamide or poly (meth) acrylonitrile. The production of a polyacrylamide with a molecular weight in the range from 500 to 5,000 daltons using thioglycolic acid as regulator and alkaline hydrolysis of 60 to 90% of the amide groups is described, for example, in US 4001161 (cyanamide). A polymer of similar composition is obtained according to US 3492240 (Nalco). The product contains 20 to 50% amide groups and 50 to 80% carboxy groups and a molecular weight in the range of 20,000 to 40,000. CA 982341 (Nalco) also discloses a hydrolyzed polyacrylonitrile which has 20 to 30% amide groups, 70 to 80% acid groups and a molecular weight of 5,000 to 40,000. Graft polymers of acrylamide or acrylonitrile on starch or vinyl alcohol and their hydrolysis products [cf. NL 66/5265 (ICI)].

(f) Other anionic or cationic polyelectrolytes. In addition to the substances mentioned, the following substances are also suitable as suitable polyelectrolytes: poly- (N, N-bis-carboxy-methylene acrylamide) [cf. GB-A 1310613 (Chemed)] copolymers of fumaric acid and vinyl sulfonic acid [cf. US 3879288, US 3706717 (Siegele)], polymers of 3-acrylamido-3-methylpropanesulfonic acid [cf. US 3709815, US 3928196 (Calgon)], copolymers of acrylic acid and styrene sulfonic acid [cf. US 4048066 (Chemed)], copolymers of acrylic acid with 2-hydroxyethyl methacrylate monophosphate [cf. JA-A 76/112447 (Sanyo)], homo- and copolymers of 3-acrylamido-3-methylbutyl-trimethylammonium chloride [cf. US 3752761 (Calgon)], copolymers of diallylglycinamide hydrochloride and acrylic acid [cf. US 3574175 (Grace)], copolymers of dimethylallylammonium chloride with acrylamide [cf. GB-A 1287489], polyethylene and / or propylene imines [cf. GB-A 1015612 (Grace)] and mixtures thereof.

Alkali hypochlorites

The aqueous bleaching agents may contain hydrogen peroxide, but they are preferably chlorine bleaching liquors containing alkali hypochlorite. Alkali hypochlorites are to be understood as lithium, potassium and in particular sodium hypochlorite. The hypochlorites can be used in amounts of 1.5 to 10, preferably 2 to 8 and in particular 4 to 6% by weight, based on the composition. buffer

In a preferred embodiment of the invention, the polyelectrolytes are used in combination with buffers which are alkali and / or alkaline earth metal silicates, carbonates, phosphonates or mixtures thereof. The salts support the sequestering effect of the polyelectrolytes and ensure that the preparations have a constantly highly alkaline pH in the range from 10 to 14. Typical examples are sodium silicate, potassium silicate, sodium carbonate, potassium carbonate and from the group of the phosphonates, in particular the amine oxide phosphonic acids sold by Bozetto / IT under the brand Sequion®. The buffers can be used alone or in mixtures in amounts of 0.01 to 5, preferably 0.1 to 2 and in particular 0.5 to 1% by weight, based on the composition.

Chlorine stable surfactants

(a) Alkyl ether sulfates. Alkyl ether sulfates are known anionic surfactants which are obtained by sulfation of nonionic surfactants of the alkylpolyglycol ether type and subsequent neutralization. The alkyl ether sulfates which are suitable for the purposes of the agents according to the invention follow the formula (III)

R ⁵ 0- (CH ₂ CH ₂ 0) _q S0 ₃ X (III)

in which R ^{5 represents} an alkyl radical having 12 to 18, in particular 12 to 14, carbon atoms, q represents numbers 2 to 5, in particular 2 to 3 and X represents sodium or potassium. Typical examples are the sodium salts of sulfates of the Ci2 / i4-coconut alcohol-2, -2,3- and -3-EO adduct. The alkyl ether sulfates can have a conventional or narrow homolog distribution. The alkyl ether sulfates are preferably used in amounts of 1 to 8, preferably 1.5 to 6 and in particular 2 to 4% by weight, based on the composition.

(b) amine oxides. Amine oxides are also known substances, which are occasionally attributed to the cationic, but usually the nonionic surfactants. They are prepared from tertiary fatty amines, which usually have either one long and two short or two long and one short alkyl radical, and are oxidized in the presence of hydrogen peroxide. The amine oxides which are suitable for the purposes of the invention follow the formula (IV)

R7

in which R ^{6 is} a linear or branched alkyl radical having 12 to 18 carbon atoms and R ⁷ and R ⁸ independently of one another are R ⁶ or an optionally hydroxyl-substituted alkyl radical having 1 to 4 carbon atoms. Amine oxides of the formula (IV) are preferably used in which R ⁶ and R ^{7 are} C1214 or C12 / 18 coconut alkyl radicals and R ^{8 is} a methyl or a hydroxyethyl radical. Also preferred are amine oxides of the formula (IV) in which R ^{6 represents} a C12 / 14 or C12 / 18 cocoalkyl radical and R ⁷ and R ^{8 have} the meaning of a methyl or hydroxyethyl radical. The amine oxides are preferably used in amounts of 1.5 to 6, preferably 2 to 4,% by weight, based on the composition.

(c) alkyl and / or alkenyl oligoglycosides. Alkyl and alkenyl oligoglycosides are known nonionic surfactants which follow the formula (V)

R ⁹ 0- [G] _p (V)

in which R ^{9 represents} an alkyl and / or alkenyl radical having 4 to 22 carbon atoms, G represents a sugar radical having 5 or 6 carbon atoms and p represents numbers from 1 to 10. They can be obtained according to the relevant procedures in preparative organic chemistry. As representative of the extensive literature, reference is made here to the documents EP-A1 0301298 and WO 90/03977. The alkyl and / or alkenyl oligoglycosides can be derived from aldoses or ketoses with 5 or 6 carbon atoms, preferably glucose. The preferred alkyl and / or alkenyl oligoglycosides are thus alkyl and / or alkenyl oligoglucosides. The index number p in the general formula (V) indicates the degree of oligomerization (DP), ie the distribution of mono- and oligoglycosides, and stands for a number between 1 and 10. While p must always be an integer in a given compound and especially here can assume the values p = 1 to 6, the value p for a certain alkyl oligoglycoside is an analytically determined arithmetic parameter, which usually represents a fractional number. Alkyl and / or alkenyl oligoglycosides with an average degree of oligomerization p of 1.1 to 3.0 are preferably used. From an application point of view, those alkyl and / or alkenyl oligoglycosides are preferred whose degree of oligomerization is less than 1.7 and is in particular between 1.2 and 1.4. The alkyl or alkenyl radical R ⁹ can be derived from primary alcohols having 4 to 11, preferably 8 to 10, carbon atoms. Typical examples are butanol, capro alcohol, caprylic alcohol, capric alcohol and undecyl alcohol and their technical mixtures, such as are obtained, for example, in the hydrogenation of technical fatty acid methyl esters or in the course of the hydrogenation of aldehydes from Roelen's oxosynthesis. Alkyl oligoglucosides of the chain length Cβ-CiQ (DP = 1 to 3) are preferred, which are obtained as a preliminary step in the separation of technical Cβ-Ciβ coconut fatty alcohol by distillation and can be contaminated with a proportion of less than 6% by weight of Ci2-alcohol and Alkyl oligoglucosides based on technical Cg / n oxo alcohols (DP = 1 to 3). The alkyl or alkenyl radical R ⁹ can also differ from primary alcohols with 12 to 22 preferably derive from 12 to 14 carbon atoms. Typical examples are lauryl alcohol, myristyl alcohol, cetyl alcohol, palmoleyl alcohol, stearyl alcohol, isostearyl alcohol, oleyl alcohol, alaidyl alcohol, petroselinyl alcohol, arachyl alcohol, gadoleyl alcohol, behenyl alcohol, erucyl alcohol, brassidyl alcohol and the technical mixtures described above, which can be obtained as well as their technical mixtures. Alkyl oligoglucosides based on hydrogenated Ci2 / 14 coconut alcohol with a DP of 1 to 3 are preferred. The glycosides are preferably used in amounts of 1.5 to 6, preferably 2 to 4% by weight, based on the composition.

(d) fatty acid salts. The agents according to the invention can contain fatty acid salts of the formula (VI) as further surfactants,

in which R ¹⁰ CO is an acyl radical having 12 to 22 carbon atoms and X is an alkali metal. Typical examples are the sodium and / or potassium salts of lauric acid, myristic acid, palmitic acid, palmoleic acid, stearic acid, isostearic acid, oleic acid, elaidic acid, petroselinic acid, linoleic acid, linolenic acid, elaeostearic acid, arachic acid, gadoleic acid, behenic acid and erucic acid and their mixtures as they occur in the pressure splitting of technical fats and oils. Salts of technical coconut or tallow fatty acids are preferably used. Since the recipes according to the invention are strongly alkaline, the fatty acids which are neutralized in situ when they are introduced into the mixture can also be used instead of the salts. Those agents according to the invention preferably contain, as an optional component, fatty acid salts in which a particular low foam level is desired. The soaps are preferably used in amounts of 1.5 to 6, preferably 2 to 4% by weight, based on the.

Industrial applicability

The bleaches obtainable using polyelectrolytes according to the invention generally have a nonaqueous fraction of 5 to 35 and preferably 8 to 15% by weight and are preferably suitable for the treatment of textile fabrics, such as yarns, fabric webs and in particular Textiles. Usually takes place their application at low temperatures, ie in the region of the cold wash (ca. 15 to 25 ^C C). The agents are not only characterized by excellent stain removal, they also reliably prevent metal traces from being deposited on the fibers and thus prevent yellowing. Although the actual use of the agents is to remove stains from laundry, they are suitable basically also for other purposes in which hypochlorite solutions are used, for example for cleaning and disinfecting hard surfaces.

Further auxiliaries and additives which may be used are, for example, other chlorine-stable surfactants or hydro tropes, such as, for example, alkyl sulfates, alkyl sulfonates, alkylbenzenesulfonates, xylene sulfonates, sarcosinates, taurides, isethionates, sulfosuccinates, betaines, sugar esters, fatty alcohol polyglycol ethers and fatty acid-N alkylglucamides. The sum of all surfactants preferably makes up at most 10 to 15% by weight of the total amount of ingredients in the formulation. The agents according to the invention can contain alkali metal compounds, preferably sodium hydroxide or potassium hydroxide, with the aid of which the pH of the recipes can be adjusted to an optimal value of 10 to 14, preferably 12.5 to 13.5.

In addition, the agents can contain active chlorine-stable fragrances, optical brighteners, dyes and pigments in a total amount of 0.01 to 0.5% by weight, based on the agents. The fragrances known to be active chlorine-resistant include, for example, monocyclic and bicyclic monoterpene alcohols and their esters with acetic or propionic acid (for example isobomeal, dihydroterpene oil, isobornyl acetate, dihydroterpenyl acetate). Other fragrances that are suitable for this purpose are mentioned, for example, in the publications EP-A1 0622451 (Procter & Gamble) and JP-A Sho 62/89800 (Raison). The optical brighteners can be, for example, the potassium salt of 4,4'-bis (1, 2,3-triazolyl) - (2 -) - stilbin-2,2-sulfonic acid, which is sold under the Phorwite® BHC brand 766 is distributed. Possible color pigments include green chlorophthalocyanines (Pigmosol® Green, Hostaphine® Green) or yellow Solar Yellow BG 300 (Sandoz). The preparation is made by stirring. If necessary, the product obtained can be decanted or filtered to remove foreign bodies and / or agglomerates. The agents also have a viscosity above 100 mPas - measured at 20 ° C in a Brookfield viscometer.

Examples

To investigate the bleaching effect, soiled tissue was treated with various bleaching solutions. The yellowing of the tissue was determined photometrically, the initial value of the soiled tissue serving as the standard (100%). The measurements were carried out in a liquor with a metal ion content of 300 ppb Fe and 100 ppb Mn; the water hardness was 1000 ppm CaCb, the hydrogen carbonate content was 0.013% by weight. The liquor ratio (tissue: water) was 1:50, the exposure time was 30 minutes at a temperature of 40 ° C. The results are summarized in Tables 1 and 2; the quantities are understood as% by weight.

Table 1

Bleaching effect - Examples according to the invention

ι Module 2.0, **) Sequion® Table 1 ^" (continued) bleaching effect

*) Polyacrylamide + Laureth-7 + Isoparaffin (SEPPIC / FR)

Table 2

Bleaching effect - comparative examples without polyelectrolytes

It can be seen that the addition of polyelectrolytes to the alkaline hypochlorite solutions leads to a significant lightening of the tissue, which can be increased even further by the addition of buffers. In contrast, the addition of buffers as sole stabilizers is sometimes still a disadvantage compared to pure hypochlorite solutions.

Claims

claims

1. Use of polyelectrolytes as sequestering agents for the production of aqueous bleaching agents.

2. Use according to claim 1, characterized in that one uses polyelectrolytes which are selected from the group formed by

(a) low molecular weight dicarboxylic acids,

(b) low molecular weight polyvalent hydroxycarboxylic acids,

(c) mono- and copolymers of unsaturated monocarboxylic acids and their esters,

(d) Homo- and copolymers of unsaturated dicarboxylic acids and their derivatives and / or

(e) Homo- and copolymers of unsaturated monocarboxamides and their derivatives.

3. Use according to claims 1 and 2, characterized in that low molecular weight dicarboxylic acids of the formula (I) are used as the polyelectrolytes of group (a),

RiOOC (CH ₂ ) _n OOCR2 (I)

in which R ¹ and R ^{2 represent} hydrogen, an alkali and / or alkaline earth metal, ammonium, alkylammonium, alkanolammonium or glucammonium and n represents numbers from 0 to 64

4. Use according to claims 1 to 3, characterized in that citric acid and / or sodium citrate is used as the polyelectrolyte of group (b).

5. Use according to claims 1 to 4, characterized in that homopolymers and copolymers are used as polyelectrolytes of group (c) which are derived from monomers of the formula (II),

CH ₂ = CR ³ (CH ₂ ) mCOOR ⁴ (II)

in which R ^{3 represents} hydrogen or a methyl group, R ^{4 represents} hydrogen or a linear or branched hydrocarbon radical having 1 to 22 carbon atoms and m represents 0 or numbers from 1 to 10.

6. Use according to claims 1 to 5, characterized in that homopolymers and copolymers of maleic anhydride are used as group (d) polyelectrolytes.

7. Use according to claims 1 to 6, characterized in that homopolymers and copolymers of group (s) of the polyacrylamide and / or of the polymethacrylamide are used as polyelectrolytes.

8. Use according to claims 1 to 7, characterized in that polyelectrolytes are used which are selected from the group formed by poly- (N, N-bis-carboxy-methylene-acrylamides), copolymers of fumaric acid and vinylsulfonic acid , Polymers of 3-acrylamido-3-methylpropanesulfonic acid, copolymers of acrylic acid and styrene sulfonic acid, copolymers of acrylic acid with 2-hydroxyethyl methacrylate monophosphate, homo- and copolymers of 3-acrylamido-3-methylbutyltrimethylammonium chloride, copolymers of diallylglycinamide hydrochloride and Acrylic acid, copolymers of dimethylallylammonium chloride with acrylamide and / or polyethylene and / or propyleneimines.

9. Use according to claims 1 to 8, characterized in that polyelectrolytes with a molecular weight in the range of 300 to 5,000,000 are used.

10. Use according to claims 1 to 9, characterized in that one uses the polyelectrolytes in amounts of 0.01 to 5 wt .-% - based on the aqueous bleaching agent.

11. Use according to claims 1 to 10, characterized in that the polyelectrolytes are used in bleaching agents containing hypochlorite.

12. Use according to claims 1 to 11, characterized in that the polyelectrolytes are used together with buffers which are selected from the group formed by alkali and / or alkaline earth metal silicates, carbonates and / or phosphonates.

13. Use according to claims 1 to 12, characterized in that the polyelectrolytes are used together with chlorine-stable surfactants which are selected from the group formed by alkyl ether sulfates, amine oxides, alkyl and / or alkenyl oligoglycosides and / or fatty acid salts.

14. Use according to claims 1 to 13, characterized in that the polyelectrolytes are used together with chlorine-stable fragrances.