FI73727B - FETTSYRA INNEHAOLLANDE TVAETTMEDELSKOMPOSITIONER. - Google Patents

Abstract

Detergent compositions, preferably heavy-duty liquids, containing an anionic surfactant, a selected cosurfactant and a fatty acid are disclosed. The compositions are formulated to provide an initial pH of from about 6.0 to about 8.5 at a concentration of from about 0.1% to about 2% by weight in water at 20 DEG C. The compositions preferably also contain ethoxylated nonionic surfactants, a detergent builder and enzymes.

Description

1 73727

Detergent mixtures containing fatty acids

The present invention relates primarily to textile detergent compositions, preferably liquid detergent compositions, comprising an anionic synthetic surfactant, a co-surfactant selected from the group consisting of certain quaternary ammonium, diquaternary ammonium, amine surfactants. and diamine compounds and fatty acid. In these compositions, the molar ratio of anionic synthetic surfactant to co-surfactant is at least 1 and is formulated to provide a wash solution starting pH of about 6.0 to about 8.5 at a concentration of about 0.1 to about 2% by weight. in water at 20 ° C. The mixtures provide both excellent removal of greasy / oily dirt and good removal of builder / pH sensitive dirt in a near neutral wash.

U.S. Patent 4,285,841 to Barrat et al. (August 25, 1981) discloses anionic surfactants, nonionic surfactants, and liquid detergents containing from about 8% to about 20% by weight of fatty acid. The pH of the mixtures is about 6.0 to 7.5.

U.S. Patent 4,287,082 to Tolfo et al. (September 1, 1981) discloses liquid detergents containing saturated fatty acids, enzymes, enzyme-reactive calcium, and selected short chain carboxylic acids.

In U.S. Patent 4,321,165, Smith et al. (March 23, 1982) discloses non-fatty detergents containing anionic, nonionic and cationic surfactants. The solution pH of the mixtures is at least about 6, and more preferably greater than 30.

The detergent composition of the invention is characterized in that it contains: a) from about 2% to about 60% by weight of an anionic synthetic surfactant; B) from about 0.5% to about 8% by weight of a co-surfactant selected from the group consisting of: ____ - ΊΓ _ 2 73727 i) surfactant quaternary ammonium compounds of the formula ZR2 (OR3) y7ZR4 (or3 ) 2r5n + x ~ 5 2 wherein R is an alkyl or alkylbenzyl group having from about 8 to about 18 carbon atoms in the alkyl chain; each R is selected from the group consisting of -CH 2 CH 2 -, -CH 2 CH (CH 3) -, -CH 2 CH (CH 2 OH) -, -CH 2 CH 2 CH 2 -, and mixtures thereof; each R 10 is selected from the group consisting of C 1-6 alkyl, C 1-4 hydroxyalkyl, benzyl, ring structures formed by combining two R 4 groups, -CH 9 CHOHCHOHCOR 6 CHOHCH 6 OH, wherein R is any hexose or hexose polymer having molecular weight up to about 1000, and hydrogen when y

Id 15 is not 0; R is the same as R or the alkyl chain in which the total number of carbon atoms contained in 2.5 R and R is at most about 18; each y is 0 to about 10 and the sum of the y values is 0 to about 15; and X is any suitable union; ii) surfactant diquartar ammonium compounds of formula ZR2 (or3) Zr4 (OR3) ^ 72n + r3n + r5Zr4 (OR3) y / 2 (x ") 2 2 3 4 5 wherein R, R, R, R, y and X are as defined above, iii) amine surfactants of formula ZR2 (OR3) y7 / R4 (OR3) y7R5N2 3 4 5 wherein R, R, R, R and y are as defined above and iv) surfactant diamine compounds of formula ZR2 (OR3) y7ZR4 (OR3) y7NR3NR5Z-R4 (OR3) 2 3 4 5 35 wherein R, R, R, R and y are as defined above and 3,73727 c) from about 5% to about 40% by weight of a fatty acid containing from about 10% to about 22 carbon atoms, wherein said mixture has a molar ratio of anionic synthetic surfactant to co-surfactant of at least 1 and is formulated as such. that it produces a wash solution to an initial pH of about 6.0 to about 8.5 at a concentration of about 0.1 to about 2% by weight in water at 20 ° C.

The detergent compositions of the invention may be in any form, including granules, liquids, tablets or pastes. However, liquid compositions are highly preferred because the compositions in this form are particularly effective when applied directly to dirt and stains during the pretreatment step. The compositions of the invention have at least one molar ratio of anionic synthetic surfactant to co-surfactant, preferably from about 2: 1 to about 20: 1, and are formulated to provide a wash solution starting pH of about 6.0. - at a concentration of about 8.5 to about 0.1% by weight in water at 20 ° C. It has been found that the addition of a co-surfactant to these fatty acid-containing detergents provides important greasy / oily soil removal benefits only at near neutral wash pH. The wash pH is preferably from about 7.0 to about 8.5, more preferably from about 7.5 to about 8.0.

While not wishing to be bound by theory, it is believed that the co-surfactant and anionic surfactant used in accordance with the invention form complexes that improve the condensation of surfactants at the oil / water interface, reducing interface tension and improving washability. (The amine and diamine surfactants would be at least partially protonated at near neutral pH and could thus form a charge species capable of complexing with the anionic surfactant). In the pH range disclosed herein, the fatty acid component is present in a chemical form that is optimal for effective washing performance. At too low a pH, the form of acid dissociation- _____ - - ΊΤ 4 73727 tons is ineffective. It is also believed that higher pHs (i.e., pH above about 8.5) affect the reaction between the fatty acid and the co-surfactant and water and result in the formation of undesired forms on the oil / water interface, which reduces the washability.

Anionic synthetic surfactant

The detergent compositions of the invention contain from about 2% to about 60% by weight of an anionic synthetic surfactant or mixtures thereof. The anionic surfactant 10 preferably comprises from about 5% to about 40%, and preferably from about 10% to about 20% by weight of the detergent composition. Anionic surfactants useful in this invention are disclosed in U.S. Patent 4,285,841 to Barrat et al. (August 25, 1981) and U.S. Patent 3,919,678 to Laughlin et al. (December 30, 1975).

Useful anionic surfactants include water-soluble salts of alkyl groups having from about 10 to about 20 carbon atoms in their molecular structure and organic sulfur reaction products containing sulfonic acid or sulfuric acid ester groups, especially alkali metal, ammonium or ammonium ammonium (e.g. triethanolammonium) salts. (The term "alkyl" includes the alkyl moiety of aryl groups). Examples of this group of synthetic surfactants are alkyl sulphates, especially those obtained by sulphation of higher alcohols (C8-C18 carbon atoms) such as those produced by reduction of tallow or coconut oil glycerides; and alkyl benzene sulfonates in which the alkyl group contains from about 9 to about 15 carbon atoms, in a straight or branched configuration, e.g., the sulfonates described in U.S. Patent 2,220,099 and 30,477,383. Of particular value are linear straight chain alkyl benzene sulfonates having an average number of carbon atoms in the alkyl group of about 11-14.

Other useful anionic surfactants include water-soluble salts of paraffin sulfonates containing from about 8 to about 24 (preferably about 5,73727 12-18) carbon atoms; alkyl glyceryl ether sulfonates, especially cetter sulfonates of C0-C 1 alcohols (e.g. derived from tallow and coconut oil); alkylphenol ethylene oxide ether sulfates containing from about 1 to about 4 ethylene oxide units per molecule and from about 8 to about 12 carbon atoms in their alkyl group; and from about 1 to about 4 ethylene oxide units per molecule and from about 10 to about 20 carbon atoms in the alkyl group, alkyl ethylene oxide ether sulfates.

Other anionic surfactants useful herein include water-soluble salts of esters of c-sulfonated fatty acids having from about 6 to about 20 carbon atoms in the fatty acid group and from about 1 to about 10 carbon atoms in the ester group; water-soluble salts of 2-acyloxyalkane-1-sulfonic acids containing from about 2 to 9 carbon atoms in the acyl group and from about 9 to about 15 carbon atoms in the alkane group; water-soluble salts of oleyl sulfonates having from about 12 to about 24 carbon atoms; and β-alkyl-20-liaoxyalkane sulfonates containing about 1 to 3 carbon atoms in the alkyl group and about 8 to 20 carbon atoms in the alkane group.

Particularly preferred union surfactants herein are alkyl sulfates of the formula RO (C "H. O) SO ~ Μ + 2 4 x 3 25 wherein R is a saturated or unsaturated alkyl chain having from about 8 to about 18 carbon atoms, and the longest alkyl chain the linear moiety has an average of 15 carbon atoms or less, M is a cation that renders the compound in aqueous solution, especially an alkali metal, ammonium, or substituted ammonium cation, and x is 0 to about 4. More preferred are non-ethoxylated primary and secondary C12-15 -alkylisulfaa-tit. Under washing conditions using cold water, i.e., the water temperature is below about 18.3 ° C, the presence of a mixture of such alkyl 35 sulfates is preferred.

_____ TT "6 73727

Mixtures of alkyl sulphates and the alkyl benzene sulphonates, paraffin sulphonates, alkyl glyceryl ether sulphonates and esters of oL-sulphonated fatty acids described above, in particular linear N-alkylbenzenesulphonates, are also preferred. Co-surfactant

The compositions of the invention also contain from about 0.5% to about 8%, preferably from about 1% to about 4% by weight of a co-surfactant selected from certain quaternary ammonium, diquaternary ammonium, amine and among diamine compounds. Quaternary ammonium surfactants are particularly preferred.

Quaternary ammonium surfactant compounds of formula 15 are useful in the invention.

Zr2 (or3) y // R4 (okj) ^ 72κ5ν + χ “2 wherein R is an alkyl or alkylbenzyl group containing from about 8 to about 18 carbon atoms in the alkyl chain; each R is selected from the group consisting of -CH 2 CH (CH 2 O) -, -CH 2 CH (CH 2 OH) -, -CH 2 CH 2 CH 2 -, and mixtures thereof; each R 4 is selected from the group consisting of C 1-4 alkyl, C 1-7 hydroxyalkyl, benzyl, ring structures formed by combining two R groups, -CH 9 CHOHCHOHCOR 6 CHOHCHOOH, 6 R 2 wherein R is any hexose or hexose polymer having a molecular weight of up to about 1000, and vetv when y 5 4 is not 0; R is the same as R or is an alkyl chain wherein 2. The total number of carbon atoms in R and R is up to about 18; each v is 0 to about 10 and the sum of the y values 30 is 0 to about 15; and X is any suitable anion.

Of the foregoing, preferred quaternary alkylammonium surfactants, especially mono-long chain alkyl surfactants described in the formula described above, when R is selected from the same groups as R. The most preferred quaternary surfactants ammonium compounds include chloride, bromide and methyl sulfate-C7-6 alkyl-tri-methylammonium salts, C1-6-alkyl di- (hydroxyethyl) motylammonium salts; Preferred additions are decyltrimethylammonium motyl sulfate, lauryltrimethylammonium chloride, myristyltrimethylammonium bromide and coconut trimethylammonium chloride and methyl sulfate.

Under washing conditions with a wash water temperature of less than about 18.3 ° C, C 1-6 alkyltrimethylammonium surfactants are particularly preferred because they have a lower Kraft limit and therefore a lower crystallization temperature than longer alkyl chains. -la with quaternary ammonium compounds.

Useful surfactant diquaternary ammonium compounds of the formula CB1 (OR2) 7 ^ R3 (OR2) 7? N + r2n + r4 / r3 (or2) 7 (x ~) yy ^ y -tz 2 3 4 are useful in the invention. Wherein R, R, R, R, y and X are as defined above for quaternary ammonium surfactants.

These substituents are also preferably selected to produce diquaternary ammonium surfactants corresponding to the preferred quaternary ammonium surfactants. Particularly preferred are C8-6 alkyl pentamethylethylenediammonium chloride, bromide and methyl sulfate salts.

Amine surfactant compounds of formula 30 are useful in the invention

ZR1 (OR2) y7 / R3 (OR2) y7R4N

3 4 5 2 wherein R, R, R, R and y are as defined above for 3 quaternary silicon ammonium surfactants.

Particularly preferred are 2-8 alkyldimethylamines.

8 73727

Useful surfactant diamine compounds of the formula / Ck2 (OR3) 77> 4 (or3) ^ 7nr3nr57'R4 (or3) 7 5 2 3 4 5 are useful in the invention.

wherein R, R, R, R and y are as defined above. Preferred are C 2-2 g-allyltrimethylethylenediamines.

Fatty acid

The compositions of the present invention contain from about 5 to about 10 to 40, preferably from about 7 to about 30, most preferably from about 10 to about 20 weight percent of a fatty acid containing from about 10 to 22 carbon atoms. The fatty acid may also contain from about 1 to about 10 ethylene oxide units in the hydrocarbon chain.

Suitable fatty acids are saturated and / or unsaturated fatty acids and can be obtained from natural sources such as vegetable or fatty esters (e.g. palm kernel oil, palm oil, coconut oil, babassu oil, sunflower oil, tall oil, castor oil, castor oil, castor oil). lard and mixtures thereof) or synthetically prepared (e.g. by oxidizing ki-20 oil or hydrogenating carbon monoxide by the Fisher-Tropsch method). Examples of suitable saturated fatty acids for use in the compositions of this invention include capric, lauric, myristic, palmitic, stearic, arachic and behenic acids. Suitable unsaturated fatty acid species include: palmitoleic, oleic, linoleic, linolenic and castor oleic acids. Examples of preferred fatty acids are saturated C 1 -C 4 (coconut) fatty acids, about 5: 1 to 1: 1 (preferably about 3: 1) weight ratio mixtures of lauric and myristic acid, and mixtures of the above lauric / myricitin mixtures with oleic acid. laurine / myristin: oil mixed in a weight ratio of about 4: 1 to 1: 4.

Optional ingredients

The compositions of the present invention also preferably contain up to about 30, preferably from about 1 to about 20, more preferably from about 5 to about 15% by weight of ethoxylated nonionic surfactant. These materials are described in U.S. Patent No. 9,737,227 to Barrat et al. (August 25, 1981). Preferred are ethoxylated alcohols and ethoxylated alkyl phenols of the formula R fC 2 H 2 H 2 OH, wherein R is selected from the group consisting of aliphatic hydrocarbon radicals containing from about 8 to about 15 carbon atoms, and alkylphenyl radicals, wherein the alkyl groups contain from about 8 to about 12 carbon atoms, and n is from about 3 to about 9, and said nonionic surfactant has an HLB (hydrophilic lipophilic equilibrium) value of from about 10 to about 13. These surfactants 10 are more completely described in U.S. Patent 4,284,532 to Leikhim et al. (18.8.1981). Particularly preferred are ethoxylated alcohols having an average of about 10 to about 15 carbon atoms in the alcohol and an average degree of ethoxylation of about 3 to about 8 moles of ethylene oxide per mole of alcohol.

The compositions of the present invention also preferably contain up to 40, more preferably from about 1 to about 30, by weight of detergent builder. Although all builders known in the art can be used in the present compositions, the type and amount of builder must be selected so that the final mixture produces a wash solution starting pH of about 6.0 to about 8.5 at a concentration of about 0.1 to about 2% by weight. in water at 20 ° C. Detergent builders are described in U.S. Patent 4,321,164 to Smith et al. (March 23, 1982). In preferred liquid detergent compositions, the builders 25 preferably comprise from about 1% to about 20%, more preferably from about 3% to about 10% by weight of the composition. Preferred builders for use in liquid detergents are described in U.S. Patent 4,284,532 to Leikhim et al. (August 18, 1982). A particularly preferred building material is citric acid.

Other preferred ingredients for use in the liquid detergents of the invention include neutralizing agents, buffers, phase regulators, hydrotropes, enzymes, enzyme stabilizers, polyacids, suds controllers, opacifiers, antioxidants, bactericides, bactericides, dyes, 4,285,841 to Barrat et al. (25.8.1981). Preferred neutralizing agents for use in the compositions of the invention are organic bases, especially triethanolamine and monoethanolamine, which result in better detergency than inorganic bases such as sodium and potassium hydroxides.

Particularly preferred compositions contain from about 0.1% to about 2% by weight of enzymes suitable for use in detergent compositions, especially amylases, proteases and mixtures thereof.

The following examples illustrate the compositions of the invention. All percentages, parts and ratios 10 used herein are by weight unless otherwise specified.

Example 1

Four sets of 7.6 cm x 7.6 cm square patches of polycotton (P / C) or cotton (C) stained with standard objects were washed in an automatic mini-15 washing machine using 2000 ppm of either mixture A, a commercially available "heavy -duty "liquid detergent; Mixture B containing 6.2% by weight of linear sodium 2-alkylbenzenesulfonate, 9.4% of sodium C 1-6 alkyl sulfate, 10.0% of C 1-4 alkylalkyl sulphate (6.5) , 10.0% coconut fatty acid, 5.0% oleic fatty acid, 15.0% citric acid, 0.3% diethylenetriaramepentamethylenephosphonic acid, 0.23% brightener, 1.0% protease enzyme, enough monoethanolamine to achieve the desired pH and equilibrium to 100% water; mixture C, which is mixture 25 B added with 2.7% by weight of C 1-2 alkyltrimethylammonium chloride; or mixture D, which is mixture B added to 2.7% by weight of C 1-12 alkyl dimethylamine oxide. The wash pH was about 7.3 for mixture A and about 7.4 for mixtures B, C and D. The temperature of the wash water was 35 ° C and the water hardness was 0.09 g / l (3: 1 Ca: Mg). The patches were dried and each set was anonymously compared to its counterparts to determine the relative removal of dirt by the detergent compositions. A grading scale of -4 to 4 was used, with -4 showing much less dirt removal, 0 showing no difference, and 4 35 showing much more dirt removal. The results for each mixture were averaged and mixture A was given a relative value of 0.

Il 11 73727

A similar comparison was made with the difference that the wash pH for mixtures B, C and D was about 9.5.

The results were as follows: 5 Mixture Wash pH 7.4 Wash pH 9.5

Lika Kangas B C D B C D

Bacon fat P / C 0.1 1.6 0.9 0.6 0.7 0.5

Synthetic P / C 0.1 1.9 2.6 -0.7 1.0 0.6 dirty engine oil 10 Make-up (oil P / C -0.5 1.5 1.6 -2.0 - 1.7 -2.6 based)

Spaghetti- P / C -1.3 -1.7 -1.8 -0.5 -0.7 -0.1 tike

Chocolate C 1.5 1.0 -0.2 -0.4 -2.0 -2.0 15 Grass P / C -1.6 1.8 2.3 3.5 3.6 4.2

Meat sauce C 0.9 0.5 1.6 4.0 3.6 3.7

Clay P / C 2.2 3.7 3.3 -1.0 0.9 -0.8

Clay C 3.2 2.9 3.5 4.1 3.6 3.2

Skin dirt P / C 0.6 0.4 0.5 0.8 1.3 0.8 20

The above results show that the mixture C of the present invention, which contains a quaternary ammonium surfactant and mixture D, provides important advantages for greasy / oily lions and also for grass and clay (by PC) compared to the washing results obtained in mixture B. at a washing pH of 7.4. However, these advantages are substantially eliminated at a wash pH of 9.5.

Example II

The liquid detergent compositions of the present invention are as follows:

Ingredient Weight%

A B

linear C 1-4 alkylbenzenesulfonic acid 5.8 5.5

Coconut alkyl sulfuric acid 8.8 8.3 35 C 1-4 alkyltrimethylammonium chloride 1,2 C 1-4 alkyltrimethylammonium bromide - 1.7 12 73727

Ingredient Weight%

A B

0χ2 x -alcohol polyethoxylate i 6 # 5) 10.0 * C, t-alcohol alcohol ethoxylate (7) - 9.4 5 Lauric acid 7.5 7.1

Myristic acid 2.5 2.3 oleic acid 5.0 4.7

Citric acid monohydrate 7.5 5.7

Diethylenetriaminepentamethylenephosphonic acid 0.3 0.3 10 Diethylenetriaminepentaacetic acid 0.3 0.3

Protease enzyme 1, Q 1.0

Amylase enzyme

Monoethanolamine 12.0

Triethanolamine 6.7 7.5 Sodium hydroxide - 3.2

Potassium hydroxide - 4,0 1,2-propanediol 5.0 8.5

Ethanol 1.0 4.7

Sodium formate 1.0 1.0 20 Sodium toluene sulphonate 5.0 Minor ingredients and water__Smoothing one hundred * 45% branched

Mixture A was prepared by adding the ingredients with constant stirring in the following order: alcohol polyethoxylate; monoethanolamine; a mixture of coconut alkyl sulfuric acid pastes (containing propanediol, triethanolamine, coconut alkyl sulfuric acid, water and minor ingredients) and alkylbenzenesulfonic acid neutralized with monoethanolamine; premix of toluenesulfonate and water; citric acid; Alkyltrimethylammonium chloride; premix of fatty acids; fos-phosphonic acid; acetic acid; a premix of color, brightener, formate, ethanol and water; adjusting the pH to about 8.1 with monoethanolamine or water; the protease enzyme; amylase enzyme; and perfume. The product obtained was a clear liquid. Its pe-35 potency was better than that of a similar product obtained by adding fatty acids before the addition of alkyltrimethylammonium chloride. The product also had better washing ability and phase stability and a less unpleasant washing odor than a similar product obtained by adding monoethanolamine after a mixture of coconut alkyl sulfuric acid paste and neutralized alkylbenzenesulfonic acid.

Mixture B was obtained by mixing the ingredients.

Other compositions of the present invention are obtained when the alkyl trimethylammonium halides in the above compositions are replaced by kookosalkyylitrimetyyliammoniumkloridil Ia-10, dekyylitrimetyyliammoniummetyylisulfaatilla, lauryl (hydroxyethyl) methylammonium chloride, ammonium chloride, decyloxy, lauryylipentametyyli-etyleenidiammoniumkloridillä, lauryylidietanoliamiinilla or kookosalkyylitrimetyylietyleenidiamiinilla.

Other mixtures of the invention are obtained when, in the above mixtures, the linear C 1-4 alkylbenzenesulfonic acid is replaced by coconut alkyl sulfuric acid or C 14 -C 5 alkyl sulfuric acid and the coconut alkyl sulfuric acid is replaced by C 14 -C 4 alkyl ethoxy (1st central) sulfuric acid.

The compositions of the present invention are also obtained by replacing the laurine / myristic / oleic fatty acid mixture in the above compositions with coconut fatty acid or a 3: 1 weight ratio mixture of lauric and myristic acids.

The granular compositions of the present invention can be obtained by spray-drying the above compositions and mixing them with heat-sensitive substances such as enzymes.

Claims (12)

14 73727 __ _ - ττ ^ A detergent composition, preferably for washing textiles, and preferably a liquid detergent, characterized in that it contains: a) from about 2% to about 60% by weight of an anionic synthetic surfactant; b) from about 0.5% to about 8% by weight of a co-surfactant selected from the group consisting of: i) quaternary ammonium surfactant compounds of the formula CR1 (OR2) y7 / R3 (or2) 2r4n + x 2 2 wherein R is an alkyl or alkylbenzyl group having from about 8 to about 18 carbon atoms in the alkyl chain; each R 2 is selected from the group consisting of -CH 2 CH 2 -, -CH 2 CH (CH 2) -, -CH 2 CH (CH 2 OH) -, -CH 2 CH 2 CH 2 -, and mixtures thereof; each R 3 is selected from the group consisting of C 1-6 alkyl, C 1-4 hydroxyalkyl, benzyl, ring structures formed by combining two R groups, -CH 2 CHOHCHOHCOR CHOHCH 2 OH with any hexose or hexose polymer having a molecular weight of up to about 1000, and hydrogen when y 5 4 is not 0; R is the same as R or is an alkyl chain in which 2 5. The total number of carbon atoms in R and R is up to about 18; each y is 0 to about 10 and the sum of the y values is 0 to about 15; and X is any suitable anion; ii) diquaternary ammonium surfactant compounds of formula ZR1 (OR2) ^ ^ 3 (OR2) y72N + R2N + R4ZR3 (OR2) 2 (X ~) 2 3 4 5 2 wherein R, R, R, R , y and X are as defined above; 3 iii) amine surfactant compounds of formula 35 4 R1 (OR2) y7 / fR3 (OR2) ^ 7R4N1573727 2 3 4 5 ... wherein R, R, R, R and y are as defined above ; and iv) diamine surfactants of the formula A mixture according to claim 1, characterized in that the anionic surfactant contains an alkyl sulphate of the formula ro (c 2 H 40) x 50 3 m + 20 wherein R is a saturated or unsaturated alkyl chain having from about 8 to about 18 carbon atoms, the longest linear the moiety comprises an average of 15 carbon atoms or less, M is a cation that renders the compound water soluble, and x is 0 to about 4. A mixture according to claim 2, characterized in that in the alkyl sulphate surfactant R is an alkyl group having from about 12 to about 15 carbon atoms, x is 0 and M is an alkali metal, ammonium or substituted ammonium cation. A composition according to claim 3, characterized in that the anionic surfactant further comprises a water-soluble salt of an alkyl benzene sulfonate, paraffin sulfonate, alkyl glyceryl ether sulfonate or o-sulfonated fatty acid ester. 16 73727 The composition of claim 3, wherein the anionic surfactant further comprises an alkali metal, ammonium, or substituted ammonium salt of a linear alkyl benzene sulfonate having from about 11 to about 14 carbon atoms in the alkyl chain. ZR2 (OR3) y7 / R4 (OR3) ir / NR3NR5 / R4 (OR3) y7 wherein R, R, R, R and y are as defined above; and c) about 5 to about 40% by weight of a fatty acid, containing from about 10 to about 22 carbon atoms, wherein said mixture has a molar ratio of anionic synthetic surfactant to co-surfactant of at least 1 and is formulated to produce a wash solution having an initial pH of about 6.0 to about 8; At a concentration of about 0.1 to about 2% by weight in water at 20 ° C. Mixture according to Claim 1, characterized in that the co-surfactant is chosen from the group consisting of chloride, bromide and methyl sulphate-C 1-6 alkyltrimethylammonium salts, C 1-6 alkyl-di (hydroxyethyl) ) methylammonium salts, C 1-6 alkylhydroxyethyldimethylammonium salts and C 1-6 alkyloxypropyltrimethylammonium salts. Mixture according to Claim 6, characterized in that the co-surfactant is decyltrimethylammonium methyl sulphate, lauryltrimethylammonium chloride, myristyltrimethylammonium bromide or coconut alkyltrimethylammonium chloride or methyl sulphate. A mixture according to claim 1, characterized in that the fatty acid contains a substance containing from about 10 to about 14 carbon atoms, or a mixture thereof. Mixture according to Claim 3, characterized in that the co-surfactant is selected from the group consisting of chloride, bromide and methyl sulphate-C 1-6 -alkyltrimethylammonium salts, C 1-6 -alkyl-di (hydroxyethyl) methylammonium salts , C 1-6 alkylhydroxyethyldimethylammonium salts and C 1-6 alkyloxypropyltrimethylammonium salts, and the fatty acid comprises a substance containing from about 10 to about 14 carbon atoms or a mixture thereof. A liquid detergent composition according to claim 9, characterized in that it contains from about 10% to about 20% by weight of an anionic synthetic surfactant, from about 1% to about 4% by weight of a co-surfactant and from about 10% to about 20% by weight. -% fatty acid. The composition of claim 10, further comprising from about 0.1% to about 2% to about 17,73727% by weight of an enzyme suitable for use in detergent compositions selected from the group consisting of amylases, proteases and mixtures thereof. . The composition of claim 11, further comprising from about 3% to about 10% by weight of citric acid. 18 73727 Patontkrav