EP2882836B1 - Automatic dishwashing composition comprising hydrobobically modified polysaccharides - Google Patents

Description

The present invention relates to the use of hydrophobically modified polysaccharides for preventing the discoloration of plastic dishes, a machine dishwashing detergent containing hydrophobically modified polysaccharides for preventing discoloration of plastic dishes, the use of this dishwashing detergent, and a machine dishwashing method using this dishwashing detergent.

If discoloration occurs in the course of machine dishwashing on plastic, this is usually the result of very color intensive foods, such as, for example, Curry, peppers, tomatoes, red cabbage, ketchup, carrots, etc., which are introduced in the form of leftovers in the dishwasher. Discolorations of the plastic, e.g. of plastic crockery, lead to dissatisfaction with the consumer, because the plastic crockery in question remains true on a purely functional level unimpaired, but many consumers as visually devalued, not sufficiently cleaned or disturbs at least the aesthetic sensibility.

Compounds for reducing the discoloration of plastics, for example, in the application WO 02/064720 described. Here it is disclosed that copolymers based on hydrophobically modified polycarboxylates suppress the discoloration of plastics. In the GB 2309975 Cellulose ethers are used to inhibit the transfer of colored food soils to plastic in automatic dishwashing. The international patent application WO 03/095602 discloses a method for removing colored stains on plastic by a component having a density of 0.6 to 1 g / l, especially paraffin oil and similar hydrocarbons, olive oil and soybean oil.

In the WO 2010/078979 the use of porous polyamide particles and synthetic phyllosilicates to reduce the discoloration of plastic dishes is disclosed.

From the international Patent Applications WO 99/31211 and WO 2006/065848 detergents or cleaners are known which include hydrophobically modified polysaccharides such as hydroxypropylcelluloses. These cellulose ethers have the advantages of being compatible with salts, possessing good solubility in various solvents, and stable under both acidic and alkaline conditions. The hydrophobically modified polysaccharides are suitable for a number of applications. From the WO 99/31211 shows that they can also be used in machine, especially in solid automatic dishwashing detergents. Thus, by way of example, dry powders containing hydrophobically modified polysaccharides can be prepared without problems. However, the property of reducing discoloration of plastic dishes during machine dishwashing can not be deduced from the references.

The object of the present invention was to provide further compounds for use in automatic dishwashing detergents which at least reduce the occurrence of discoloration on plastics in the course of automatic dishwashing as a result of colored food residues.

A first subject of the present invention is therefore the use of hydrophobically modified polysaccharides selected from hydroxypropylmethylcellulose (HPMC) and / or hydroxyethylmethylcellulose (HEMC). for reducing the discoloration of plastic dishes in automatic dishwashing processes. In this case, the reduction in discoloration is generally to be understood as meaning that the transfer of dyes, resulting from colored food residues, to plastic utensils when they are being cleaned in an automatic dishwashing machine is at least reduced, in the best case even completely suppressed. However, this also means that a change in the color impression of plastic dishes during its cleaning in an automatic dishwashing machine is at least reduced and in the best case completely suppressed.

Another object of the present invention is a machine dishwashing detergent containing sulfonic acid-containing polymers as a softener and further at least one hydrophobically modified polysaccharide selected from HPMC and / or HEMC. Another object of the present invention is the use of a machine dishwashing detergent according to the invention for preventing and / or reducing the staining of plastic and / or for preventing the change in the color impression of plastic dishes during its cleaning in an automatic dishwashing machine

A further subject matter of the present invention is a machine dishwashing process in which a machine dishwasher detergent according to the invention is used in particular for the purpose of reducing and / or preventing the discoloration of plastics.

• orangerote Carotinoide wie z.B. Lycopin oder beta-Carotin, z.B. aus Tomaten, Ketchup oder Möhren,
• gelbe Curcumafarbstoffe, wie z.B. Curcumin, z.B. aus Curry und Senf.

Surprisingly, hydrophobically modified cellulose derivatives exhibit the property of enabling a substantial prevention or at least a marked reduction in the discoloration of plastic materials during the automatic dishwashing process, while hydrophilic cellulose derivatives modified with carboxylic acid or sulphonic acid groups such as carboxymethylcellulose or sulphoethylcellulose have no effect or only an insufficient effect demonstrate. The hydrophobically modified cellulose derivatives are hydroxyethylmethylcellulose, hydroxypropylmethylcellulose, or a mixture thereof. The change in the color impression of plastic dishes during its cleaning in an automatic dishwashing machine can be avoided or at least reduced. The transfer of dyes, resulting from colored food residues on plastic utensils when it is cleaned in an automatic dishwasher can be suppressed or at least reduced. Particularly effective, the transmission of the following dyes can be inhibited or at least reduced:

• orange-red carotenoids such as lycopene or beta-carotene, for example from tomatoes, ketchup or carrots,
• yellow curcuma dyes, such as curcumin, eg from curry and mustard.

• rote bis blaue Anthocyanfarbstoffe, wie z.B. Cyanidin, z.B. aus Kirschen oder Heidelbeeren,
• rotes Betanidin, z.B. aus der roten Beete,
• braune Gerbstoffe, z.B. aus Tee, Obst, Rotwein
• tiefbraune Huminsäure, z.B. aus Kaffee, Tee, Kakao,
• grünes Chlorophyll, z.B. aus grünen Kräutern.

Optionally, furthermore, the transfer of the following dyes can be inhibited:

• red to blue anthocyanin dyes, such as cyanidin, for example from cherries or blueberries,
• red betanidin, eg from the red bed,
• brown tannins, eg from tea, fruit, red wine
• deep brown humic acid, eg from coffee, tea, cocoa,
• green chlorophyll, eg from green herbs.

In particular, white and light-colored plastic materials benefit from the invention. The plastic materials are in a preferred embodiment of polyethylene or polypropylene.

In view of the above, hydrophobically modified cellulose derivatives include hydroxyethylmethylcellulose (HEMC), hydroxypropylmethylcellulose (HPMC), or mixtures thereof, or mixtures of at least one of these hydrophobically modified cellulose derivatives with other cellulose derivatives. These other cellulose derivatives can then also be hydrophilic nature such as carboxymethyl cellulose or sulfoethyl cellulose.

Cellulose derivatives can be obtained, for example, under the names Ethocel®, Methocel®, Walocel® or Cellosize® from The Dow Chemical Company.

Hydroxypropylmethylcellulose (HPMC) and hydroxyethylmethylcellulose (HEMC) have proven particularly advantageous in the context of the present invention.

The hydrophobically modified polysaccharides and in particular the hydrophobically modified cellulose derivatives are usually used in amounts of from 0.1 to 10% by weight, based on the total formulation of the agent used. Below the specified minimum quantity, the effects are generally insufficient, whereas above the stated maximum quantity no further overall performance advantages are found. Preferred amounts of hydrophobically modified cellulose derivatives and especially of HPMC and / or HEMC are 1 to 8% by weight and in particular 2 to 6% by weight.

Although the machine dishwashing detergent according to the invention does not contain sulfonic acid-modified cellulose derivatives in a preferred embodiment, it does contain sulfonic acid-containing polymers in addition to the hydrophobically modified cellulose derivatives, which are usually used as softeners in automatic dishwashing detergents. Such sulfonic acid-containing polymers are known to those skilled in the literature. Particularly preferred as sulfonic acid-containing polymers are copolymers of unsaturated carboxylic acids, sulfonic acid-containing monomers and optionally other ionic or nonionic monomers.

Preferred copolymeric sulfopolymers contain not only sulfonic acid-containing monomer (s) but also at least one monomer selected from the group consisting of unsaturated carboxylic acids.

Unsaturated carboxylic acid (s) used are, with particular preference, unsaturated carboxylic acids of the formula R ¹ (R ² ) C =C (R ³ ) COOH, in which R ¹ to R ³ independently of one another are -H, -CH ₃ , a straight-chain or branched saturated alkyl radical having 2 to 12 carbon atoms, a straight-chain or branched, mono- or polyunsaturated alkenyl radical having 2 to 12 carbon atoms, alkyl or alkenyl radicals substituted by -NH ₂ , -OH or -COOH as defined above or -COOH or -COOR ⁴ , wherein R ^{4 is} a saturated or unsaturated, straight-chain or branched hydrocarbon radical having 1 to 12 carbon atoms.

Particularly preferred unsaturated carboxylic acids are acrylic acid, methacrylic acid, ethacrylic acid, α-chloroacrylic acid, α-cyanoacrylic acid, crotonic acid, α-phenyl-acrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, citraconic acid, methylenemalonic acid, sorbic acid, cinnamic acid or mixtures thereof.

In the sulfonic acid-containing monomers are those of the formula

R ⁵ (R ⁶ ) C = C (R ⁷ ) -X-SO ₃ H

in which R ⁵ to R ⁷ independently of one another are -H, -CH ₃ , a straight-chain or branched saturated alkyl radical having 2 to 12 carbon atoms, a straight-chain or branched, mono- or polyunsaturated alkenyl radical having 2 to 12 carbon atoms, NH ₂ , -OH or -COOH substituted alkyl or alkenyl radicals or -COOH or -COOR ⁴ , wherein R ^{4 is} a saturated or unsaturated, straight-chain or branched hydrocarbon radical having 1 to 12 carbon atoms, and X is an optional spacer group which is selected from - (CH ₂ ) _n - with n = 0 to 4, -COO- (CH ₂ ) _k - with k = 1 to 6, -C (O) -NH-C (CH ₃ ) ₂ - , -C (O) -NH-C (CH ₃ ) ₂ -CH ₂ - and -C (O) -NH-CH (CH ₃ ) -CH ₂ -.

Among these monomers are those of the formulas

H ₂ C = CH-X-SO ₃ H

H ₂ C = C (CH ₃ ) -X-SO ₃ H

HO ₃ SX (R ⁶⁾ C = C (R ⁷⁾ -X-SO ₃ H

Preferred in which R ⁶ and R ^{7 are} independently selected from -H, -CH ₃ , -CH ₂ CH ₃ , -CH ₂ CH ₂ CH ₃ and -CH (CH ₃ ) ₂ and X is an optional spacer group which is selected from - (CH ₂ ) _n - with n = 0 to 4, -COO- (CH ₂ ) _k - with k = 1 to 6, -C (O) -NH-C (CH ₃ ) ₂ - , -C (O) -NH-C (CH ₃ ) ₂ -CH ₂ - and -C (O) -NH-CH (CH ₃ ) -CH ₂ -.

Particularly preferred monomers containing sulfonic acid groups are 1-acrylamido-1-propanesulfonic acid, 2-acrylamido-2-propanesulfonic acid, 2-acrylamido-2-methyl-1-propanesulfonic acid, 2-methacrylamido-2-methyl-1-propanesulfonic acid, 3 Methacrylamido-2-hydroxypropanesulfonic acid, allylsulfonic acid, methallylsulfonic acid, allyloxybenzenesulfonic acid, methallyloxybenzenesulfonic acid, 2-hydroxy-3- (2-propenyloxy) propanesulfonic acid, 2-methyl-2-propenylsulfonic acid, styrenesulfonic acid, vinylsulfonic acid, 3-sulfopropyl acrylate, 3-sulfopropyl methacrylate , Sulfomethacrylamide, sulfomethylmethacrylamide and mixtures of said acids or their water-soluble salts.

In the polymers, the sulfonic acid groups may be wholly or partially in neutralized form, i. the acidic acid of the sulfonic acid group in some or all sulfonic acid groups can be exchanged for metal ions, preferably alkali metal ions and in particular for sodium ions. The use of partially or fully neutralized sulfonic acid-containing copolymers is preferred according to the invention.

The monomer distribution of the copolymers preferably used according to the invention in the case of copolymers containing only monomers containing carboxylic acid groups and monomers containing sulfonic acid groups is preferably in each case from 5 to 95% by weight, particularly preferably Proportion of the sulfonic acid group-containing monomer 50 to 90 wt .-% and the proportion of the carboxylic acid group-containing monomer 10 to 50 wt .-%, the monomers are hereby preferably selected from the aforementioned.

The molar mass of the sulfo copolymers preferably used according to the invention can be varied in order to adapt the properties of the polymers to the desired end use. Preferred automatic dishwashing agents are characterized in that the copolymers have molar masses of from 2000 to 200,000 gmol ^-1 , preferably from 4000 to 25,000 gmol ^-1 and in particular from 5000 to 15,000 gmol ^-1 .

In a further preferred embodiment, in addition to the carboxyl group-containing monomer and the monomer containing the sulfonic acid group, the copolymers further comprise at least one nonionic, preferably hydrophobic monomer. The use of these hydrophobically modified polymers has made it possible in particular to improve the rinse aid performance of automatic dishwashing detergents according to the invention.

1. i) Carbonsäuregruppen-haltige Monomer(e)
2. ii) Sulfonsäuregruppen-haltige Monomer(e)
3. iii) nichtionische Monomer(e).

In a further preferred embodiment of the invention, the agents contain at least one anionic copolymer comprising

1. i) carboxylic acid group-containing monomer (s)
2. ii) sulfonic acid group-containing monomer (s)
3. iii) nonionic monomer (s).

The nonionic monomers used are preferably monomers of the general formula R ¹ (R ² ) C =C (R ³ ) -XR ⁴ , in which R ¹ to R ³ independently of one another are -H, -CH ₃ or -C ₂ H ₅ , X represents an optionally present spacer group selected from -CH ₂ -, -C (O) O- and -C (O) -NH-, and R ^{4 represents} a straight-chain or branched saturated alkyl radical having 2 to 22 carbon atoms or represents an unsaturated, preferably aromatic radical having 6 to 22 carbon atoms.

Particularly preferred nonionic monomers are butene, isobutene, pentene, 3-methylbutene, 2-methylbutene, cyclopentene, hexene, hexene-1, 2-methylpentene-1, 3-methylpentene-1, cyclohexene, methylcyclopentene, cycloheptene, methylcyclohexene, 2,4 , 4-trimethylpentene-1, 2,4,4-trimethylpentene-2,3,3-dimethylhexene-1, 2,4-dimethylhexene-1, 2,5-dimethlyhexene-1,3,5-dimethylhexene-1,4 , 4-dimethylhexane-1, ethylcyclohexyn, 1-octene, α-olefins having 10 or more carbon atoms such as 1-decene, 1-dodecene, 1-hexadecene, 1-octadecene and C22-α-olefin, 2-styrene, α Methylstyrene, 3-methylstyrene, 4-propylstryol, 4-cyclohexylstyrene, 4-dodecylstyrene, 2-ethyl-4-benzylstyrene, 1-vinylnaphthalene, 2, vinylnaphthalene, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, acrylic acid pentyl ester, Acrylsäurehexylester, methyl methacrylate, N- (methyl) acrylamide, acrylic acid 2-ethylhexyl ester, methacrylic acid 2-ethylhexyl ester, N - (2-ethylhexyl) acrylamide, octyl acrylate, Methacrylsäureoctylester, N - (octyl) acrylamide, (lauryl acrylate, lauryl methacrylate, N- Lauryl) acrylamide, stearyl acrylate, stearyl methacrylate, N - (stearyl) acrylamide, behenyl acrylate, behenyl methacrylate and N - (behenyl) acrylamide or mixtures thereof.

The automatic dishwashing agents according to the invention can be solid or liquid in nature and, in particular, can be in the form of powdery solids, in densified particle form, as homogeneous solutions or suspensions. In a further preferred embodiment of the invention, the automatic dishwashing detergent is present in a pre-portioned form. In a further preferred embodiment of the invention, the automatic dishwashing detergent has a plurality of spatially separate compositions, whereby it is possible to separate incompatible ingredients from one another, or to offer compositions in combination, which are used at different times in the dishwasher. This is particularly advantageous if the automatic dishwashing detergents are present in pre-portioned form. At least one of the compositions is solid and / or at least one of the compositions is liquid, wherein the hydrophobically modified polysaccharides are contained in at least one of the compositions, but can also be present in several compositions.

The agents according to the invention preferably comprise at least one further constituent, in particular at least two further constituents selected from the group consisting of builders, surfactants, polymers, bleaches, bleach activators, bleach catalysts, in particular catalysts based on manganese or cobalt, enzymes, corrosion inhibitors and glass corrosion inhibitors, Disintegration aids, fragrances and perfume carriers.

If desired, an agent according to the invention may, in addition to the active ingredients mentioned, additionally comprise a further, known color transfer inhibitor, then preferably in amounts of from 0.01% by weight to 5% by weight, in particular from 0.1% by weight to 1% by weight. %, contain. In a preferred embodiment of the invention, for example, a polymer of vinylpyrrolidone, vinylimidazole, vinylpyridine-N-oxide or a copolymer of these can be used. Useful are both polyvinylpyrrolidones having molecular weights of from 15,000 to 50,000 and also polyvinylpyrrolidones having molecular weights of more than 1,000,000, in particular from 1,500,000 to 4,000,000, N-vinylimidazole / N-vinylpyrrolidone copolymers, polyvinyl oxazolidones, polyamine N-oxide Polymers, polyvinyl alcohols and copolymers based on acrylamidoalkenylsulfonic acids.

Polyvinylpyrrolidone preferably has an average molecular weight in the range from 10 000 to 60 000, in particular in the range from 25 000 to 50 000, for use in compositions according to the invention. Among the copolymers, those of vinylpyrrolidone and vinylimidazole in a molar ratio of 5: 1 to 1: 1 having an average molecular weight in the range of 5,000 to 50,000, especially 10,000 to 20,000 are preferred.

As further known color transfer inhibitors, it is possible to use porous polyamide particles and / or synthetic sheet silicates and / or glycerol esters.

The following describes possible ingredients which can be advantageously used in the machine dishwashing detergents according to the invention.

Advantageously, builders can be used. The builders include, in particular, the zeolites, silicates, carbonates, organic cobuilders and, where there are no ecological prejudices against their use, also the phosphates.

Preference is given to using crystalline layer-form silicates of the general formula NaMSi _x O _{2x + 1} .yH ₂ O, where M is sodium or hydrogen, x is a number from 1.9 to 22, preferably from 1.9 to 4, with particularly preferred Values for x are 2, 3 or 4, and y is a number from 0 to 33, preferably from 0 to 20. The crystalline layer-form silicates of the formula NaMSi _x O _{2x + 1} .yH ₂ O are for example sold by Clariant GmbH (Germany) under the trade name Na-SKS. Examples of these silicates are Na-SKS-1 (Na ₂ Si ₂₂ O ₄₅ .xH ₂ O, Kenyaite), Na-SKS-2 (Na ₂ Si ₁₄ O ₂₉ .xH ₂ O, magadiite), Na-SKS-3 (Na ₂ Si ₈ O ₁₇ · x H ₂ O) or Na-SKS-4 (Na ₂ Si ₄ O ₉ · xH ₂ O, makatite). Particularly suitable for the purposes of the present invention are crystalline phyllosilicates of the formula NaMSi _x O _{2x + 1} .yH ₂ O, in which x is 2. In particular, both β- and δ-sodium disilicates are Na ₂ Si ₂ O ₅ .yH ₂ O and furthermore, in particular, Na-SKS-5 (α-Na ₂ Si ₂ O ₅ ), Na-SKS-7 (β-Na ₂ Si ₂ O _5, natrosilite), Na-SKS-9 (NaHSi ₂ O ₅ · H ₂ O), Na-SKS-10 (NaHSi ₂ O5 · 3H ₂ O, kanemite), Na-SKS-11 (t-Na ₂ Si ₂ O ₅ ) and Na-SKS-13 (NaHSi ₂ O ₅ ), but especially Na-SKS-6 (δ-Na ₂ Si ₂ O ₅ ).

Machine dishwashing detergents preferably contain a weight fraction of the crystalline layered silicate of the formula NaMSi _x O _{2x + 1} · yH ₂ O of from 0.1 to 20% by weight, preferably from 0.2 to 15% by weight and in particular of 0.4 to 10 wt .-%, each based on the total weight of these agents.

It is also possible to use amorphous sodium silicates with a Na ₂ O: SiO ₂ modulus of from 1: 2 to 1: 3.3, preferably from 1: 2 to 1: 2.8 and in particular from 1: 2 to 1: 2.6, which preferably delayed release and have secondary washing properties. The release delay opposite conventional amorphous sodium silicates may have been caused in various ways, for example by surface treatment, compounding, compaction / densification or by overdrying. In the context of this invention, the term "amorphous" is understood to mean that the silicates do not yield sharp X-ray reflections typical of crystalline substances in X-ray diffraction experiments, but at most one or more maxima of the scattered X-rays having a width of several degrees of diffraction angle , cause.

In the context of the present invention, it is preferred that these silicate (s), preferably alkali metal silicates, particularly preferably crystalline or amorphous Alkalidisilikate, in the compositions in amounts of from 3 to 60 wt .-%, preferably from 8 to 50 wt. % and in particular from 20 to 40 wt .-%, each based on the weight of the automatic dishwashing detergent are included.

Of course, a use of the well-known phosphates as builders is possible, unless such use should not be avoided for environmental reasons. Of the large number of commercially available phosphates, the alkali metal phosphates, with particular preference of pentasodium or Pentakaliumtriphosphat (sodium or potassium tripolyphosphate) in the washing or cleaning industry have the greatest importance.

Alkali metal phosphates is the summary term for the alkali metal (especially sodium and potassium) salts of various phosphoric acids, in which one can distinguish metaphosphoric acids (HPO ₃ ) _n and orthophosphoric H ₃ PO _{4 in} addition to higher molecular weight representatives. The phosphates combine several advantages: they act as alkali carriers, prevent lime deposits on machine parts or lime incrustations in fabrics and also contribute to the cleaning performance.

Technically particularly important phosphates are the pentasodium triphosphate, Na ₅ P ₃ O ₁₀ (sodium tripolyphosphate) and the corresponding potassium salt pentapotassium triphosphate, K ₅ P ₃ O ₁₀ (potassium tripolyphosphate). Preferably usable according to the invention are the sodium potassium tripolyphosphates.

If phosphates are used as washing or cleaning substances in machine dishwashing detergent in the present application, preferred agents comprise this phosphate (s), preferably alkali metal phosphate (s), particularly preferably pentasodium or pentapotassium triphosphate (sodium or potassium tripolyphosphate ), in amounts of 5 to 80 wt .-%, preferably from 15 to 75 wt .-% and in particular from 20 to 70 wt .-%, each based on the weight of the automatic dishwashing detergent.

Further builders are the alkali carriers. Suitable alkali carriers are, for example, alkali metal hydroxides, alkali metal carbonates, alkali metal hydrogencarbonates, alkali metal sesquicarbonates, the cited alkali metal silicates, alkali metal silicates, and mixtures of the abovementioned substances, it being possible to use the alkali metal carbonates, in particular sodium carbonate, sodium bicarbonate or sodium sesquicarbonate, for the purposes of this invention. Particularly preferred is a builder system comprising a mixture of tripolyphosphate and sodium carbonate. Also particularly preferred is a builder system comprising a mixture of tripolyphosphate and sodium carbonate and sodium disilicate. Because of their low chemical compatibility with the other ingredients of dishwasher detergents in comparison with other builders, the optional alkali metal hydroxides are preferably only in small amounts, preferably in amounts below 10 wt .-%, preferably below 6 wt .-%, more preferably below 4 % By weight and in particular below 2% by weight, in each case based on the total weight of the automatic dishwashing detergent. Particularly preferred are agents which, based on their total weight, contain less than 0.5% by weight and in particular no alkali metal hydroxides.

Particularly preferred is the use of carbonate (s) and / or bicarbonate (s), preferably alkali metal carbonate (s), more preferably sodium carbonate, in amounts of 2 to 50 wt .-%, preferably from 5 to 40 wt .-% and in particular from 7.5 to 30 wt .-%, each based on the weight of the automatic dishwashing detergent. Particularly preferred are agents which, based on the weight of the automatic dishwashing detergent, contain less than 20% by weight, preferably less than 17% by weight, preferably less than 13% by weight and in particular less than 9% by weight of carbonate (e ) and / or bicarbonate (s), preferably alkali metal carbonate (s), particularly preferably sodium carbonate.

Particularly suitable organic co-builders are polycarboxylates / polycarboxylic acids, polymeric polycarboxylates, aspartic acid, polyacetals, dextrins, further organic cobuilders and phosphonates. These classes of substances are described below.

Useful organic builders are, for example, the polycarboxylic acids which can be used in the form of the free acid and / or their sodium salts, polycarboxylic acids meaning those carboxylic acids which carry more than one acid function. For example, these are citric acid, adipic acid, succinic acid, glutaric acid, malic acid, tartaric acid, maleic acid, fumaric acid, sugar acids, nitrilotriacetic acid (NTA), if such use is not objectionable for ecological reasons, and mixtures thereof. In addition to their builder effect, the free acids also typically have the property of an acidifying component and thus also serve to set a lower and milder pH of the automatic dishwashing detergents. In particular, here are citric acid, Succinic acid, glutaric acid, adipic acid, gluconic acid and any mixtures thereof.

The use of citric acid and / or citrates in these compositions has proved to be particularly advantageous for the cleaning and rinsing performance of agents according to the invention. Therefore, automatic dishwashing detergents are preferred according to the invention in that the automatic dishwashing agent contains citric acid or a salt of citric acid and the weight fraction of citric acid or of the salt of citric acid is preferably more than 10% by weight, preferably more than 15% by weight in particular between 20 and 40 wt .-% is.

Another important class of phosphate-free builders are aminocarboxylic acids and / or their salts. Particularly preferred members of this class are methylglycinediacetic acid (MGDA) or its salts, and glutamic diacetic acid (GLDA) or its salts or ethylenediaminediacetic acid or its salts (EDDS). The content of these aminocarboxylic acids or their salts may for example be between 0.1 and 15% by weight, preferably between 0.5 and 10% by weight and in particular between 0.5 and 6% by weight. Aminocarboxylic acids and their salts can be used together with the abovementioned builders, in particular also with the phosphate-free builders.

Further suitable builders are polymeric polycarboxylates, for example the alkali metal salts of polyacrylic acid or of polymethacrylic acid, for example those having a relative molecular mass of from 500 to 70,000 g / mol.

Suitable polymers are, in particular, polyacrylates which preferably have a molecular weight of 2,000 to 20,000 g / mol. Because of their superior solubility, the short-chain polyacrylates, which have molar masses of from 2000 to 10000 g / mol, and particularly preferably from 3000 to 5000 g / mol, may again be preferred from this group.

Also suitable are copolymeric polycarboxylates, in particular those of acrylic acid with methacrylic acid and of acrylic acid or methacrylic acid with maleic acid. Copolymers of acrylic acid with maleic acid which contain 50 to 90% by weight of acrylic acid and 50 to 10% by weight of maleic acid have proven to be particularly suitable. Their relative molecular weight, based on free acids, is generally from 2000 to 70000 g / mol, preferably from 20,000 to 50,000 g / mol and in particular from 30,000 to 40,000 g / mol.

The (co) polymeric polycarboxylates can be used either as a powder or as an aqueous solution. The content of the automatic dishwashing agents in (co) polymeric polycarboxylates is preferably from 0.5 to 20% by weight and in particular from 3 to 10% by weight.

To improve the water solubility, the polymers may also contain allylsulfonic acids such as allyloxybenzenesulfonic acid and methallylsulfonic acid as a monomer.

Further preferred copolymers are those which have as their monomers acrolein and acrylic acid / acrylic acid salts or acrolein and vinyl acetate.

In addition, all compounds capable of forming complexes with alkaline earth ions can be used as builders.

The compositions of the invention may contain surfactants, wherein the nonionic, the anionic, the cationic and the amphoteric surfactants are counted among the group of surfactants.

As nonionic surfactants, it is possible to use all nonionic surfactants known to the person skilled in the art. Suitable nonionic surfactants are, for example, alkyl glycosides of the general formula RO (G) _x in which R corresponds to a primary straight-chain or methyl-branched, especially methyl-branched, 2-position aliphatic radical having 8 to 22, preferably 12 to 18, carbon atoms and G is the symbol which is a glycose unit having 5 or 6 C atoms, preferably glucose. The degree of oligomerization x, which indicates the distribution of monoglycosides and oligoglycosides, is any number between 1 and 10; preferably x is 1.2 to 1.4.

Another class of preferred nonionic surfactants which can be used either as the sole nonionic surfactant or in combination with other nonionic surfactants are alkoxylated, preferably ethoxylated or ethoxylated and propoxylated fatty acid alkyl esters, preferably having from 1 to 4 carbon atoms in the alkyl chain.

Nonionic surfactants of the amine oxide type, for example N-cocoalkyl-N, N-dimethylamine oxide and N-tallowalkyl-N, N-dihydroxyethylamine oxide, and the fatty acid alkanolamides may also be suitable. The amount of these nonionic surfactants is preferably not more than that of the ethoxylated fatty alcohols, especially not more than half thereof.

Further suitable surfactants are the polyhydroxy fatty acid amides known as PHFA.

Low-foaming nonionic surfactants can be used as preferred surfactants. With particular preference, the automatic dishwashing detergents contain nonionic surfactants from the group of the alkoxylated alcohols. As nonionic surfactants are preferably alkoxylated, advantageously ethoxylated, in particular primary alcohols having preferably 8 to 18 carbon atoms and an average of 1 to 12 moles of ethylene oxide (EO) per mole of alcohol used, in which the alcohol radical may be methyl linear or preferably in the 2-position methyl-branched or linear and methyl-branched radicals in the mixture, as they are usually present in Oxoalkoholresten. In particular, however, alcohol ethoxylates with linear radicals of alcohols of natural origin having 12 to 18 carbon atoms, for example of coconut, palm, tallow or oleyl alcohol, and on average 2 to 8 moles of EO per mole of alcohol are preferred. The preferred ethoxylated alcohols include, for example, C _12-14 alcohols with 3 EO or 4 EO, C _9-11 alcohols with 7 EO, C _13-15 alcohols with 3 EO, 5 EO, 7 EO or 8 EO, C _12-18 alcohols with 3 EO, 5 EO or 7 EO and mixtures of these, such as mixtures of C _12-14 -alcohol with 3 EO and C _12-18 -alcohol with 5 EO. The stated degrees of ethoxylation represent statistical averages, which may correspond to a particular product of an integer or a fractional number. Preferred alcohol ethoxylates have a narrow homolog distribution (narrow range ethoxylates, NRE). In addition to these nonionic surfactants, fatty alcohols with more than 12 EO can also be used. Examples include tallow fatty alcohol with 14 EO, 25 EO, 30 EO or 40 EO.

Particular preference is given to nonionic surfactants which have a melting point above room temperature. Nonionic surfactant (s) having a melting point above 20 ° C, preferably above 25 ° C, more preferably between 25 and 60 ° C and especially between 26.6 and 43.3 ° C, is / are particularly preferred ,

Preferably used surfactants come from the groups of alkoxylated nonionic surfactants, in particular the ethoxylated primary alcohols and mixtures of these surfactants with structurally complicated surfactants such as polyoxypropylene / polyoxyethylene / polyoxypropylene ((PO / EO / PO) surfactants). Such (PO / EO / PO) nonionic surfactants are also characterized by good foam control.

bevorzugt, in der R¹ für einen geradkettigen oder verzweigten, gesättigten oder ein- bzw. mehrfach ungesättigten C_6-24-Alkyl- oder -Alkenylrest steht; jede Gruppe R² bzw. R³ unabhängig voneinander ausgewählt ist aus -CH₃, -CH₂CH₃, -CH₂CH₂-CH₃, CH(CH₃)₂ und die Indizes w, x, y, z unabhängig voneinander für ganze Zahlen von 1 bis 6 stehen.In the context of the present invention, particularly preferred nonionic surfactants have been low foaming nonionic surfactants which have alternating ethylene oxide and alkylene oxide units. Among these, in turn, surfactants with EO-AO-EO-AO blocks are preferred, wherein in each case one to ten EO or AO groups are bonded to each other before a block of the other groups follows. Here are nonionic surfactants of the general formula

in which R ^{1 is} a straight-chain or branched, saturated or mono- or polyunsaturated C _6-24 alkyl or alkenyl radical; each group R ² or R ^{3 is} independently selected from -CH ₃ , -CH ₂ CH ₃ , -CH ₂ CH ₂ -CH ₃ , CH (CH ₃ ) ₂ and the indices w, x, y, z independently stand for integers from 1 to 6.

Thus, particularly preferred are nonionic surfactants having a C _9-15 alkyl radical having 1 to 4 ethylene oxide units followed by 1 to 4 propylene oxide units followed by 1 to 4 ethylene oxide units followed by 1 to 4 propylene oxide units. These surfactants have the required low viscosity in aqueous solution and can be used according to the invention with particular preference.

Surfactants of the general formula

R ^{1 is} -CH (OH) CH ₂ O- (AO) _w - (A "O) _x - (A" O) _y - (A '"O) _z -R ² ,

in the
R ¹ and R ² independently represent a straight-chain or branched, saturated or mono- or polyunsaturated C _2-40 alkyl or alkenyl radical; A, A ', A "and A'" independently represent a radical from the group -CH ₂ CH ₂ , -CH ₂ CH ₂ -CH ₂ , -CH ₂ -CH (CH ₃ ), -CH ₂ -CH ₂ -CH ₂ -CH ₂ , -CH ₂ -CH (CH ₃ ) -CH ₂ -, -CH ₂ -CH (CH ₂ -CH ₃ ); and w, x, y and z are values between 0.5 and 90, where x, y and / or z can also be 0, are particularly preferred according to the invention.

Very particularly preferred nonionic surfactants in a preferred embodiment have the general formula R ¹ O [CH ₂ CH (CH ₃ ) O] _x [CH ₂ CH ₂ O] _y [CH ₂ CH (CH ₃ ) O] _z CH ₂ CH ( OH) R ² in which R ^{1 is} a linear or branched aliphatic hydrocarbon radical having 4 to 22 carbon atoms or mixtures thereof, R ² denotes a linear or branched hydrocarbon radical having 2 to 26 carbon atoms, in particular 4 to 20 carbon atoms, or mixtures thereof and x and z are values between 0 and 40 and y is a value of at least 15.

The stated C chain lengths and degrees of ethoxylation or degrees of alkoxylation of the abovementioned nonionic surfactants represent statistical mean values which, for a specific product, may be an integer or a fractional number. Due to the manufacturing process, commercial products of the formulas mentioned are usually not made of an individual representative, but of mixtures, which may result in mean values for the C chain lengths as well as for the degrees of ethoxylation or degrees of alkoxylation and subsequently broken numbers.

Anionic surfactants can also be used as a component of automatic dishwashing detergents. These include in particular alkylbenzenesulfonates, (fatty) alkyl sulfates, (fatty) alkyl ether sulfates and alkanesulfonates. The content of the anionic surfactant is usually 0 to 10% by weight.

worin jede Gruppe R¹ unabhängig voneinander ausgewählt ist aus C_1-6-Alkyl-, -Alkenyl- oder -Hydroxyalkylgruppen; jede Gruppe R² unabhängig voneinander ausgewählt ist aus C_8-28-Alkyl- oder -Alkenylgruppen; R³ = R¹ oder (CH₂)_nT-R²; R⁴ = R¹ oder R² oder (CH₂)_n-T-R²; T = -CH₂-, -O-CO- oder -CO-O- und n eine ganze Zahl von 0 bis 5 ist.Instead of the surfactants mentioned or in conjunction with them, it is also possible to use cationic and / or amphoteric surfactants. As cationic active substances, for example, cationic compounds of the following formulas can be used:

wherein each R ^{1 group is} independently selected from C _1-6 alkyl, alkenyl or hydroxyalkyl groups; each R ^{2 group is} independently selected from C _8-28 alkyl or alkenyl groups; R ³ = R ¹ or (CH ₂ ) _n TR ² ; R ⁴ = R ¹ or R ² or (CH ₂ ) _n -TR ² ; T = -CH ₂ -, -O-CO- or -CO-O- and n is an integer from 0 to 5.

In automatic dishwashing detergents, the content of cationic and / or amphoteric surfactants is preferably less than 6% by weight, preferably less than 4% by weight, very particularly preferably less than 2% by weight and in particular less than 1% by weight. %. Automatic dishwashing detergents containing no cationic or amphoteric surfactants are particularly preferred.

The group of polymers includes, in particular, the washing or cleaning-active polymers, for example the rinse aid polymers and / or polymers which act as softeners. In general, cationic, anionic and amphoteric polymers can be used in machine dishwashing detergents in addition to nonionic polymers.

"Cationic polymers" in the context of the present invention are polymers which carry a positive charge in the polymer molecule. This can be done, for example, in the polymer chain present (alkyl) ammonium groups or other positively charged groups can be realized. Particularly preferred cationic polymers come from the groups of quaternized cellulose derivatives, the polysiloxanes with quaternary groups, the cationic guar derivatives, the polymeric dimethyldiallylammonium salts and their copolymers with esters and amides of acrylic acid and methacrylic acid, the copolymers of vinylpyrrolidone with quaternized derivatives of dialkylamino and methacrylates, the vinylpyrrolidone-methoimidazolinium chloride copolymers, the quaternized polyvinyl alcohols or the polymers specified under the INCl designations Polyquaternium 2, Polyquaternium 17, Polyquaternium 18 and Polyquaternium 27.

For the purposes of the present invention, "amphoteric polymers" furthermore have, in addition to a positively charged group in the polymer chain, also negatively charged groups or monomer units. These groups may be e.g. to act carboxylic acids, sulfonic acids or phosphonic acids.

Preferred employable amphoteric polymers are from the group of the alkylacrylamide / acrylic acid copolymers, the alkylacrylamide / methacrylic acid copolymers, the alkylacrylamide / methylmethacrylic acid copolymers, the alkylacrylamide / acrylic acid / alkylaminoalkyl (meth) acrylic acid copolymers, the alkylacrylamide / methacrylic acid / alkylaminoalkyl (meth ) -acrylic acid copolymers, the alkylacrylamide / methylmethacrylic acid / alkylaminoalkyl (meth) acrylic acid copolymers, the alkylacrylamide / alkymethacrylate / alkylaminoethylmethacrylate / alkylmethacrylate copolymers and the copolymers of unsaturated carboxylic acids, cationically derivatized unsaturated carboxylic acids and optionally further ionic or nonionic monomers.

Preferably usable zwitterionic polymers are selected from the group of acrylamidoalkyltrialkylammonium chloride / acrylic acid copolymers and their alkali metal and ammonium salts, the acrylamidoalkyltrialkylammonium chloride / methacrylic acid copolymers and their alkali metal and ammonium salts and the methacroylethylbetaine / methacrylate copolymers.

• die Verkapselung der Polymere mittels wasserlöslicher oder wasserdispergierbarer Beschichtungsmittel, vorzugsweise mittels wasserlöslicher oder wasserdispergierbarer natürlicher oder synthetischer Polymere;
• die Verkapselung der Polymere mittels wasserunlöslicher, schmelzbarer Beschichtungsmittel, vorzugsweise mittels wasserunlöslicher Beschichtungsmittel aus der Gruppe der Wachse oder Paraffine mit einem Schmelzpunkt oberhalb 30°C;
• die Cogranulation der Polymere mit inerten Trägermaterialien, vorzugsweise mit Trägermaterialien aus der Gruppe der wasch- oder reinigungsaktiven Substanzen, besonders bevorzugt aus der Gruppe der Builder (Gerüststoffe) oder Cobuilder.

In a particularly preferred embodiment of the present invention, the polymers are present in prefabricated form. For the preparation of the polymers is suitable inter alia

• the encapsulation of the polymers by means of water-soluble or water-dispersible coating compositions, preferably by means of water-soluble or water-dispersible natural or synthetic polymers;
• the encapsulation of the polymers by means of water-insoluble, meltable coating compositions, preferably by means of water-insoluble coating agents from the group of waxes or paraffins having a melting point above 30 ° C;
• the co-granulation of the polymers with inert carrier materials, preferably with carrier materials from the group of washing- or cleaning-active substances, more preferably from the group of builders or cobuilders.

Machine dishwashing detergents preferably contain the abovementioned cationic and / or amphoteric polymers in amounts of from 0.01 to 10% by weight, based in each case on the total weight of the automatic dishwashing detergent. In the context of the present application, however, preference is given to those automatic dishwasher detergents in which the weight fraction of the cationic and / or amphoteric polymers is between 0.01 and 8% by weight, preferably between 0.01 and 6% by weight, preferably between 0, 01 and 4 wt .-%, particularly preferably between 0.01 and 2 wt .-% and in particular between 0.01 and 1 wt .-%, each based on the total weight of the automatic dishwashing detergent is.

The bleaching agents are a substance which can be used with particular preference for washing or cleaning. Among the compounds serving as bleaches in water H ₂ O ₂ , sodium percarbonate, sodium perborate tetrahydrate and sodium perborate monohydrate are of particular importance. Other useful bleaching agents are, for example, peroxypyrophosphates, citrate perhydrates and H ₂ O ₂ -producing peracidic salts or peracids, such as perbenzoates, peroxophthalates, diperazelaic acid, phthaloimino peracid or diperdodecanedioic acid. It is also possible to use all other inorganic or organic peroxy bleaches known to the person skilled in the art.

As a bleaching agent and chlorine or bromine releasing substances can be used. Among the suitable chlorine or bromine releasing materials are, for example, heterocyclic N-bromo- and N-chloroamides, for example trichloroisocyanuric acid, tribromoisocyanuric acid, dibromoisocyanuric acid and / or dichloroisocyanuric acid (DICA) and / or their salts with cations such as potassium and sodium. Hydantoin compounds such as 1,3-dichloro-5,5-dimethylhydantoin are also suitable.

According to the invention, automatic dishwashing agents are preferred which contain from 1 to 35% by weight, preferably from 2.5 to 30% by weight, particularly preferably from 3.5 to 20% by weight and in particular from 5 to 15% by weight of bleaching agent, preferably sodium percarbonate , contain.

As bleach activators, it is possible to use compounds which, under perhydrolysis conditions, give aliphatic peroxycarboxylic acids having preferably 1 to 10 C atoms, in particular 2 to 4 C atoms, and / or optionally substituted perbenzoic acid. Of all the bleach activators known to the person skilled in the art, polyacylated alkylenediamines, in particular tetraacetylethylenediamine (TAED), acylated triazine derivatives, in particular 1,5-diacetyl-2,4-dioxohexahydro-1,3,5-triazine (DADHT), acylated glycolurils, in particular tetraacetylglycoluril (TAGU), N-acylimides, especially N-nonanoylsuccinimide (NOSI), acylated phenolsulphonates, in particular n -Nonanoyl or Isononanloxybenzolsulfonat (n- or iso-NOBS) is particularly preferably used. Combinations of conventional bleach activators can also be used. These bleach activators are preferably used in amounts of up to 10% by weight, in particular from 0.1% by weight to 8% by weight, especially from 2 to 8% by weight and more preferably from 2 to 6% by weight, based in each case on the total weight of bleach activator-containing agents.

Enzymes can also be used to increase the washing or cleaning performance of automatic dishwasher detergents. These include in particular proteases, amylases, lipases, hemicellulases, cellulases, perhydrolases or oxidoreductases, and preferably mixtures thereof. These enzymes are basically of natural origin; Starting from the natural molecules, improved variants are available for use in automatic dishwasher detergents, which can be used correspondingly preferred. Machine dishwashing detergents preferably contain enzymes in total amounts of 1 ^× 10 ^-6 to 5% by weight, based on active protein. The protein concentration can be determined by known methods, for example the BCA method or the biuret method. However, it is also possible to use enzymatic systems comprising a peroxidase and hydrogen peroxide or a substance which produces hydrogen peroxide in water. The addition of a mediator compound for the peroxidase, for example an acetosyringone, a phenol derivative or a phenotiazine or phenoxazine, is preferred in this case, with the above-mentioned conventional polymeric color transfer inhibiting agents can additionally be used.

The enzymes can be used in any form known in the art. These include, for example, the solid preparations obtained by granulation, extrusion or lyophilization or, especially in the case of liquid or gel-form detergents, solutions of the enzymes, advantageously as concentrated as possible, sparing in water and / or added with stabilizers.

Alternatively, the enzymes may be encapsulated for both the solid and liquid dosage forms, for example by spray-drying or extruding the enzyme solution together with a preferably natural polymer or in the form of capsules, for example those in which the enzymes are entrapped as in a solidified gel or in those of the core-shell type, in which an enzyme-containing core is coated with a water, air and / or chemical impermeable protective layer. Preferably, a plurality of enzymes and / or enzyme preparations, preferably protease preparations and amylase preparations, in amounts of from 0.1 to 5 wt .-%, preferably from 0.2 to 4.5 wt .-% and in particular from 0.4 to 4 wt .-%, each based on the total enzyme-containing agent used.

Glass corrosion inhibitors prevent the occurrence of haze, streaks and scratches, but also iridescence of the glass surface of machine-cleaned glasses. Preferred glass corrosion inhibitors come from the group of magnesium and zinc salts and magnesium and zinc complexes. In the context of the present invention, the content of zinc salt in dishwasher detergents is preferably between 0.1 and 5 wt.%, Preferably between 0.2 and 4 wt.% And in particular between 0.4 and 3 wt the content of zinc in oxidized form (calculated as Zn ²⁺ ) is between 0.01 and 1% by weight, preferably between 0.02 and 0.5% by weight and in particular between 0.04 and 0.2% by weight .-%, each based on the total weight of the glass corrosion inhibitor-containing agent.

In order to facilitate the disintegration of preformed moldings, it is possible to incorporate disintegration aids, so-called tablet disintegrants, into these compositions in order to shorten the disintegration times. By tablet disintegrants or disintegrants are meant excipients which ensure the rapid disintegration of tablets in water or other media and for the rapid release of the active ingredients. Desintegration aids may preferably be used in amounts of from 0.5 to 10% by weight, preferably from 3 to 7% by weight and in particular from 4 to 6% by weight, based in each case on the total weight of the disintegration assistant-containing agent.

As perfume oils or perfumes, within the scope of the present invention, individual fragrance compounds, e.g. the synthetic products of the ester, ether, aldehyde, ketone, alcohol and hydrocarbon type are used. Preferably, however, mixtures of different fragrances are used, which together produce an attractive fragrance. Such perfume oils may also contain natural fragrance mixtures such as are available from vegetable sources, e.g. Pine, citrus, jasmine, patchouli, rose or ylang-ylang oil.

The preparation of automatic dishwashing agents according to the invention can take place in different ways. The agents may be in solid or liquid form as well as in a combination of solid and liquid forms. Powder, granules, extrudates, compacts, in particular tablets, are particularly suitable as firm supply forms. The liquid supply forms based on water and / or organic solvents may be thickened, in the form of gels. Inventive agents can be formulated in the form of single-phase or multi-phase products. In particular, automatic dishwashing detergents with one, two, three or four phases are preferred. Machine dishwashing detergent, characterized in that it is in the form of a prefabricated dosing unit with two or more phases, are particularly preferred. The individual phases of multiphase agents may be the same or different Have aggregate states. Machine dishwashing detergents which have at least two different solid phases and / or at least two liquid phases and / or at least one solid and at least one solid phase are preferred.

Automatic dishwasher detergents according to the invention are preferably prefabricated to form metering units. These metering units preferably comprise the necessary for a cleaning cycle amount of washing or cleaning-active substances. Preferred metering units have a weight between 12 and 30 g, preferably between 14 and 26 g and in particular between 16 and 22 g. In order to achieve an optimum cleaning and rinse-aid result, preference is given to those automatic dishwashing agents which are present in the form of a prefabricated dosing unit and between 0.001 and 1 g, preferably between 0.01 and 0.1 g, particularly preferably between 0.01 and 0, 07 g and in particular between 0.01 and 0.05 g of the polymer a) or between 0.1 and 2.5 g, preferably between 0.2 and 2.2 g, particularly preferably between 0.3 and 1.9 g and in particular between 0.4 and 1.5 g of nonionic (s) surfactant (s) b). The volume of the aforementioned metering units and their spatial form are selected with particular preference so that a metering of the prefabricated units is ensured via the metering chamber of a dishwasher. The volume of the dosing unit is therefore preferably between 10 and 35 ml, preferably between 12 and 30 ml.

The automatic dishwasher detergents according to the invention, in particular the prefabricated metering units, have a water-soluble coating, with particular preference.

The subject matter of the present application is furthermore a method for cleaning dishes in a dishwashing machine, in which the agent according to the invention is metered into the interior of a dishwasher during the passage of a dishwashing program before the main wash cycle or during the main wash cycle. The metering or the entry of the agent according to the invention into the interior of the dishwasher can be done manually, but preferably the agent is metered by means of the metering chamber into the interior of the dishwasher.

A typical framework formulation for a machine dishwashing detergent preferably used, for example in tablet form, comprises the following substances: Na tripolyphosphate 20-50% by weight sodium 10-30% by weight sodium 5-18% by weight bleach 0.5-5% by weight bleach catalyst 0.01-1% by weight sulfopolymer 2.5-15% by weight polycarboxylate 0.1-10% by weight nonionic surfactant 0.5-10% by weight phosphonate 0.5-5% by weight protease 0.1-5% by weight amylase 0.1-5% by weight, the data in% by weight are based on the total agent. Instead of the or part of the tripolyphosphate, it is also possible in particular to use 10-50% by weight of citrate or MGDA or GLDA or EDDS or mixtures of two or three of these substances in the formulation.

Examples Example 1: Inhibition of the Staining of Plastic in Automatic Dishwashing (Test Arrangement)

0.73 g of a soil mixture (composition see Table 1) were combined with 10 g of Lupolen® PE-HD (polyethylene spheres, BASF) in 25 ml of water with a hardness of 21 ° dH. 0.12 g (corresponding to 20 g per 4 liters) of a powdered automatic dishwashing detergent (composition see Table 2) and various amounts of the additive to be investigated were added. The mixture was stirred rapidly for 10 minutes at room temperature and then filtered. From the filtrate, 5 ml was taken, added with 5 ml of toluene, shaken for 1 minute and then centrifuged until a phase separation occurred. Using UV-VIS spectroscopy, 1 ml of the toluene phase was examined and the amount of dye quantified. The absorption of the main peak at 484 nm was used for comparison. For comparison, the extinctions of the pure soil mixture in water, the soil mixture with the polymer beads and the soil mixture with polymer beads and the automatic dishwashing agent were measured.

Higher amounts of dye in the solution mean that less dye is applied to the plastic (here: the polyethylene spheres).

The values given in Table 3 are the means from a triplicate. Table 1: Composition of the soil mixture in% by weight olive oil 12.8 Vinegar essence 4.2 tomato ketchup 68.0 Paprika spice 3.2 Curry spice 3.2 common salt 8.6 phosphate 40.0 sodium 13.5 phosphonate 2.5 Sulfonic acid group-containing polymer 5.5 polyacrylate 8.5 Nonionic surfactants 6.5 percarbonate 15.5 TAED 2.5 bleach catalyst 1.0 amylase 0.8 protease 2.4 zinc acetate 0.2 leftovers ad 100 0.73 g of dirt 0.72 0.73 g + 10 g Lupolen® PE-HD 0.1 0.73 g + 10 g Lupolen® PE-HD + 0.12 g dishwashing detergent 0.2 0.73 g + 10 g Lupolen® PE-HD + 0.12 g dishwashing detergent + 3.125 mg HPMC 0.30 0.73 g + 10 g Lupolen® PE-HD + 0.12 g dishwashing detergent + 6.25 mg HPMC 0.32 0.73 g + 10 g Lupolen® PE-HD + 0.12 g dishwashing detergent + 12.5 mg HPMC 0.50 0.73 g + 10 g Lupolen® PE-HD + 0.12 g dishwashing detergent + 6.25 mg HEMC 0.45 0.73 g + 10 g Lupolen® PE-HD + 0.12 g dishwashing detergent + 6.25 mg CMC 0.24 0.73 g + 10 g Lupolen® PE-HD + 0.12 g dishwashing detergent + 6.25 mg sulfoethyl cellulose 0.24

The table clearly shows that additions of hydroxypropylmethylcellulose (HPMC) and of hydroxyethylmethylcellulose lead to a marked improvement in discoloration inhibition, while carboxymethylcellulose (CMC) and sulfoethylcellulose give only a very slight improvement over the dishwashing detergent alone.

Example 2: Inhibition of staining of plastic in automatic dishwashing (practice test)

Polyethylene breakfast board (PE board) and polypropylene breakfast board (PP board) were subjected to a machine dishwashing process (AEG Proclean dishwasher, Quick program (55 ° C, 50 minutes, water hardness 21 ° dH) g of the soil composition given in Table 1. To clean the breakfast boards, 20 g of the powdered automatic dishwashing detergent indicated in Table 2 and the amounts of added additive indicated in Table 4 were dosed before and after rinsing using a colorimeter (Datacolor DC 600 -3) the values L, a and b were measured and the ΔE value was then determined from these values: the lower the determined ΔE value, the smaller is the soiling of the boards The results are shown in Table 4. The higher the The difference between the ΔE values is, the clearer the color difference (see Table 5). Table 4: ΔE values and ΔE value difference to base value AE AE difference PE board + dishwashing detergent (underlying) 9.17 PE board + dishwashing detergent + 1 g HPMC 6.4 2.77 PE board + dishwashing detergent + 1 g HEMC 5.15 4.02 PP board + dishwashing detergent (underlying) 6.98 PP board + dishwashing detergent 4.23 2.75 AE difference rating 0,0 .... 0,5 No to almost no difference 0.5 .... 1.0 Difference visible to the trained eye 1.0 .... 2.0 Noticeable color difference 2.0 .... 4.0 Noticeable color difference 4.0 .... 5.0 Essential color difference Bigger 5.0 Difference is rated as a different color

Claims (10)

1. The use of hydrophobically modified polysaccharides for reducing staining of plastics tableware in automatic dishwashing methods, wherein the hydrophobically modified polysaccharides are selected from hydroxypropyl methylcellulose (HPMC) and/or hydroxyethyl methylcellulose (HEMC).
2. An automatic dishwasher detergent, containing, as softeners, polymers that contain sulfonic acid groups, characterized in that the agent additionally contains at least one hydrophobically modified polysaccharide, the at least one hydrophobically modified polysaccharide being selected from hydroxypropyl methylcellulose (HPMC) and/or hydroxyethyl methylcellulose (HEMC).
3. An embodiment according to claim 2, characterized in that the agent comprises HPMC and/or HEMC in amounts of from 0.1 to 10 wt.%, in particular from 1 to 8 wt.% and particularly preferably from 2 to 6 wt.%.
4. The embodiment according to one of claims 2 or 3, characterized in that the agent is in solid form.
5. The embodiment according to one of claims 2 or 3, characterized in that the agent is in liquid form.
6. The embodiment according to one of claims 2 or 3, characterized in that the agent is in pre-portioned form.
7. The embodiment according to one of the preceding claims, characterized in that the agent contains a plurality of compositions which are spatially separate from one another, of which at least one composition is present in solid form and/or one composition is present in liquid form, the hydrophobically modified polysaccharides being contained in at least one of the compositions.
8. The embodiment according to one of the preceding claims, characterized in that the agent contains at least one additional component, preferably at least two additional components, selected from the group consisting of builders, surfactants, polymers, bleaching agents, bleach activators, bleach catalysts, enzymes, corrosion inhibitors, glass corrosion inhibitors, disintegration aids, fragrances, and scent carriers.
9. The use of an automatic dishwasher detergent according to one of the preceding claims for inhibiting and/or reducing staining of plastics material and/or for preventing a change in the perceived color of plastics tableware during cleaning thereof in an automatic dishwasher.
10. An automatic dishwashing method, characterized in that an automatic dishwasher detergent according to one of claims 2 to 8 is used.