Cleansing composition

Abstract: The invention provides a cleansing composition, which comprises in addition to water, (a) from 10 to 30.% by weight of one or more C₆ tO C₁₆ acyl lactylates and (b) from 5 to 25% by weight of one or more co-surfactants, such as acyl taurates, isethionates, sarcosinates and sulphosuccinates. The cleansing compositions are primarily intended to be used as personal washing products, such as facial wash foams, bath foams and hair shampoos.

Description: FIELD OF THE INVENTION The invention relates to cleansing compositions. In particular, the invention is concerned with very mild and high foaming cleansing compositions suitable for cleansing the skin and hair. BACKGROUND TO THE INVENTION AND PRIOR ART The most widely used anionic surfactants in cleansing compositions are alkyl sulphates, polyoxyethylene alkyl sulphates and alkyl benzene sulphonates. These compounds are known to have a good foaming and deterging power. Due to their harshness, however, they are not desirable as components for cleansing compositions topically applied to human skin and hair. Their damaging effect particularly where young, tender or damaged skin is involved, has been the subject of intense study for many years. On the other hand milder surfactants often suffer from the draw-back that they do not provide high foam which is very important for the consumer. Therefore, there is a strong need for products which are not only very mild but also possess an excellent foaming power. US-A-3,728,447 (C J Patterson) discloses hair shampoo compositions containing fatty acid lactylates or glycolates. While the cleaning action of shampoos based on the fatty acid lactylates is satisfactory the foam is minimal. In order to achieve higher foaming action it is described to include harsh detergents such as sodium lauryl sulphate or triethanolamine lauryl sulphate. When the lactylates are used in conjunction with such a booster detergent the quantity of the lactylates present in the composition is reduced down to about 1 to 2% by weight. EP-A-224 796 (Kao) describes a detergent composition comprising (a) a phosphate surfactant and (b) an acyl lactylate having an acyl group containing 12 to 18 carbons atoms. The detergent composition is said to have excellent foaming characteristics as well as excellent detergency and mildness to the skin and hair. It is taught that these characteristics are only achievable if the acyl lactylate is used in an amount of not more than 5% by weight and preferably not more than 3% by weight of the composition. EP-A-371 803 (Unilever) describes a composition suitable for topical application to the skin or hair comprising (a) a phosphate surfactant and (b) an acyl lactylate surfactant. US-A-4,761,279 (Eastman Kodak) describes shaving cream formulations comprising salts of acyl lactylates, saturated monoglycerides, propyleneglycol mono esters and humectants. US-A-4,946,832 (RITA Corporation) describes cosmetic base compositions comprising 1 to 15% by weight sucrose fatty acid ester, 3 to 45% by weight acyl lactylate or its alkali metal salts and solvent. The compositions promote wound healing and reduces skin dryness. Foaming properties of the compositions are not reported. Applicants in their search for mild cleansing compositions, in particular for cleansing human skin or hair, with the added attribute that full lather is produced, have unexpectedly discovered that a narrow range of acyl lactylates in combination with specific co-surfactants provide the desired effects when used in particular amounts. The compositions so obtained are capable of producing a superior lather and accordingly have great consumer appeal. Also, the compositions are so mild that they can safely be used for cleansing the skin and the hair and other more delicate skin areas. DEFINITION OF THE INVENTION Accordingly, the invention provides a cleansing composition which comprises, in addition to water, (a) from 10 to 35% by weight of one or more acyl lactylate(s) of the following structure (1) where R 1 CO represents a C 6 to C 16 acyl radical; a is an integer from 1 to 3; M 1 represents hydrogen or a counterion chosen from alkali metal, ammonium or a substituted ammonium group having one or more C 1 to C 3 alkyl or hydroxy alkyl group(s); and (b) from 5 to 25% by weight of one or more co-surfactant (s) chosen from the following compounds (A) to (O): (A) N-methyl-N-acyl taurates of the following structure (2) where R 2 CO represents a C 10 to C 18 acyl group; and M 2 is as M 1 in structure (1); (B) Acylisethionates of the following structure (3) R 3 CO ― OCH 2 CH 2 ― SO 3 M 3 where R 3 CO represents a C 10 to C 18 acyl group; and M 3 is as M 1 in structure (1); (C) Alkylesters of ω-sulphonated carboxylic acids of the following structure (4) where R 4 represents a C 10 to C 18 alkyl group; M 4 is as M 1 in structure (1); and (b) is an integer from 1 to 3; (D) Fatty acylamido polyoxyethylene sulphates of the following structure (5) R 5 CO ― NH ― (CH 2 CH 2 O) c ― SO 3 M 5 where R 5 CO represents a C 10 to C 18 acyl group; M 5 is as M 1 in structure (1); and c is an integer from 1 to 10; (E) Fatty acid polyglyceride sulphates of the following structure (6) R 6 CO ― O ― (CH 2 - CHOH - CH 2 O) d ― SO 3 M 6 where R 6 CO represents a C 10 to C 18 acyl group; M 6 is as M 1 in structure (1); and d is an integer from 1 to 4; (F) Mono substituted sulphosuccinates of the following structures (7a) or (7b) where Z 7 is chosen from the following groups (i) to (iii): (i) R a CO - NH - (CH 2 CH 2 O) e -, where R a CO represents a C 10 to C 18 acyl group; and e is an integer from 1 to 10; (ii) R b - O - (CH 2 CH 2 O) f -, where R b represents a C 10 to C 18 alkyl group; and f is an integer from 1 to 10; (iii) R c - O -, where R c represents a C 10 to C 18 alkyl group; and X 7 and Y 7 are independently from each other chosen from the counterions represented by M 1 in structure (1); (G) Alkyl poly(ethylene glycol) acetates of the following structure (8) where R 9 represents a C 10 to C 18 alkyl group; M 9 is as M 1 in structure (1); and h is an integer from 1 to 10; (H) Salts of N-acyl α-amino acids of the following structure (9) where R 10 CO represents a C 10 to C 18 acyl group; Z 10 represents H or C 1 to C 2 alkyl; Y 10 represents H, C 1 to C 3 alkyl or C 1 to C 3 alkyl substituted with a COOH group; and M 10 is chosen from the counterions represented by M 1 in structure (1); (I) Alkyl polyglucosides of the following structure (10) where R 11 represents a C 10 to C 14 alkyl group; and n is an integer from 1 to 3; (J) Poly(oxyalkylene) fatty alkyl ether of the following structure (11) R 12 ― O ― (Z 12 O) p H where R 12 represents a C 8 to C 18 alkyl group; Z 12 is a C 2 or C 3 alkylene group; and p is an integer from 1 to 10; (K) N-substituted betaines of the following structure (12) where Z 13 represents (i) a C 10 to C 18 alkyl group; or (ii) a R 13 CO - NH - (CH 2 ) 3 group, where R 13 CO represents a C 10 to C 18 acyl group; (L) Sultaines of the following structure (13) where Z 14 represents a C 10 to C 18 alkyl group or a C 10 to C 18 acyl amido group; (M) Alkyl amphocarboxylates of the following structure (14) where R 15 CO represents a C 10 to C 18 acyl group; Z 15 and Y 15 are independently from each other chosen from H, CH 2 CH 2 OH or (CH 2 ) r COO - ; r is 1 or 2; and M 15 is as M 1 in structure (1); the composition having a foam height of more than 130mm, as measured by the foam height test described herein. DISCLOSURE OF THE INVENTION The Acyl lactylate The composition according to the invention comprises from 10 to 35% by weight of one or more acyl lactylate(s) of the following structure (1) where R 1 CO represents a C 6 to C 16 acyl radical; a is an integer from 1 to 3; M 1 represents hydrogen or a counterion chosen from alkali metal, ammonium or substituted ammonium group having one or more C 1 to C 3 alkyl or hydroxy alkyl group(s). Examples of acyl lactylates having the above structure (1) include: Sodium lauroyl monolactylate Sodium myristoyl monolactylate Sodium decanoyl monolactylate Potassium dodecanoyl monolactylate Potassium dodecanoyl dilactylaate Sodium myristoyl dilactylate Sodium lauroyl dilactylate Lauroyl dilactylic acid Palmitoyl dilactylic acid Triethanolammonium dodecanoyl monolactylate ammonium decanoyl monolactylate, and Triethanolammonium decanoyl monolactylate. The preferred acyl group R 1 CO is a C 10 to C 14 acyl group. Preferred examples for M 1 include sodium, potassium, ammonium and triethanolammonium. The amount of the acyl lactylate present in the composition according to the invention is preferably from 15 to 30%, most preferred from 20 to 30% by weight of the composition. The Co-surfactant The composition according to the invention further comprises one or more co-surfactant(s) in an amount from 5 to 25% by weight of the composition. The co-surfactant is chosen from the compounds (A) to (O) described hereinafter. The preferred amount of the co-surfactant present in the composition is from 10 to 25% by weight. The co-surfactants useful in the present invention are not only very mild but also result in high foaming compositions when combined with the acyl lactylate in the specified amounts. The following compounds are suitable as co-surfactant in the cleansing composition according to the invention. ( A ) N-methyl-N-acyl taurates , having the following structure (2) where R 2 CO represents a C 10 to C 18 acyl group; and M 2 is as M 1 in structure (1). Preferred examples for taurates having the structure (2) include: Sodium N-methyl-N-cocoyl taurate, eg. available as Diapon K from Nippon Oil and Fats, Sodium N-methyl-N-lauroyl taurate, eg. available as Diapon LM from Nippon Oils and Fats, Sodium N-methyl-N-myristoyl taurate , eg. available as Nikkol MMT from Nikkol Chemicals. ( B ) Acylisethionates , having the structure (3); R 3 CO ― OCH 2 CH 2 ― SO 3 M 3 where R 3 CO represents a C 10 to C 18 acyl group; and M 3 is as M 1 in structure (1). The preferred example for an Acylisethionate having the structure (3) is sodium cocoyl isethionate, eg. available as Fenopon AC 78 from Rhone Poulenc. ( C ) Alkylesters of ω-sulphonated carboxylic acids , having the structure (4); where R 4 represents a C 10 to C 18 alkyl group; M 4 is as M 1 in structure (1); and (b) is an integer from 1 to 3. The preferred example for an Alkylester of a ω-sulphonated carboxylic acid having the structure (4) is sodium lauryl sulphoacetate, eg. available as Lathanol LAL from Stepan or as Nikkol LSA and Nikkol Chemicals. ( D ) Fatty acylamido polyoxyethylene sulphates , having the structure (5); R 5 CO ― NH ― (CH 2 CH 2 O) c ― SO 3 M 5 where R 5 CO represents a C 10 to C 18 acyl group; M 5 is as M 1 in structure (1); and c is an integer from 1 to 10. The preferred example for a sulphate having the structure (5) is sodium cocoyl amide EO-3 sulphate, eg. available as Sunamide C-3 from Nippon Oils & Fats. ( E ) Fatty acyl polyglyceride sulphates , having the structure (6); R 6 CO ― O ― (CH 2 - CHOH - CH 2 O) d ― SO 3 M 6 where R 6 CO represents a C 10 to C 18 acyl group; M 6 is as M 1 in structure (1); and d is an integer from 1 to 4; A preferred example for a fatty acyl poly(glyceride) sulphate having the structure (6) is sodium cocoyl monoglyceride sulphate, available from Jan Dekker International. ( F ) Mono substituted sulphosuccinates , having the structures (7a) or (7b); where Z 7 is chosen from the following groups (i) to (iii): (i) R a CO - NH - (CH 2 CH 2 O) e - , where R a CO represents a C 10 to C 18 acyl group; and e is an integer from 1 to 10; (ii) R b - O - (CH 2 CH 2 O) f -, where R b represents a C 10 to C 18 alkyl group; and f is an integer from 1 to 10; (iii) R c - O -, where R c represents a C 10 to C 18 aklyl group; and X 7 and Y 7 are independently from each other chosen from the counterions represented by M 1 in structure (1). Preferred examples for mono substituted sulphosuccinates represented by the structures (7a) and (7b) include: Disodium lauroyl amido (EO)-2 to 3 sulphosuccinate eg. available as Beaulight A-5000 from Sanyo Chemicals, a mixture of Disodium lauryl (PEG)-2 sulphosuccinate and Disodium myristyl (PEG)-2 sulphosuccinate, eg. available as Beaulight ESS from Sanyo Chemicals, Disodium lauryl (PEG)-2 to 3 sulphosuccinate, eg. available as Rewopol SBFA 30 from Rewo, and Disodium lauryl sulphosuccinate, eg. available as Beaulight SSS from Sanyo Chemicals. The short form (EO)-2 to 3 denotes that, as an average value, 2 to 3 oxyethylene groups are present per molecule sulphosuccinate. On the other hand, the short form (PEG)-2 to 3 stands for the presence of a polyethylene glycol group derived from, as an average value, 2 to 3 ethylene glycol molecules per molecule sulphosuccinate. (G) Alkyl poly(ethylene glycol) acetate , having the structure (8), where R 9 represents a C 10 to C 18 alkyl group; M 9 is as M 1 in structure (1); and h is an integer from 1 to 10. Preferred examples for Alkyl (PEG) acetates having the structure (8) include, Sodium Cocoyl PEG-10 acetate, eg. available as Marlinat CM 105 from Huls, and Sodium tridecyl (PEG)-3 acetate, eg. available as Beaulight ECA from Sanyo Chemicals. ( H ) Salts of N-acyl α-amino acids , having the structure (9); where R 10 CO represents a C 10 to C 18 acyl group; Z 10 represents H or C 1 to C 2 alkyl; Y 10 represents H, C 1 to C 3 alkyl or C 1 to C 3 alkyl substituted with a COOH group; and M 10 is chosen from the counteriouns represented by M 1 in structure (1). Preferred examples for salts of N-acyl α-amino acids having the structure (9) include: Sodium N-lauroyl glutamate, available as Amisoft, LS-11 from Ajinomoto Inc., Sodium N-cocoyl glutamate, eg. available as Amisoft CS-11 from Ajinomoto Inc., Triethanolammonium N-cocoyl sarcosinate, eg. available as Firet KT from Nippon Oil and Fats, Sodium N-decanoyl sarcosinate, Sodium N-lauroyl alaninate, eg. available as Alaninate LN-30 from Nikkol Chemicals, Sodium N-cocoyl alaninate, Sodium N-cocoyl aspartate, and Sodium N-lauroyl aspartate. ( I ) Alkyl poly glucoside , having the structure (10); where R 11 represents a C 10 to C 14 alkyl group; and n is an integer from 1 to 3. Preferred examples for Alkyl poly glucosides having the structure (10) include; Decyl poly glucoside (n = 1.44), eg. available as Oramix NS10 from Seppic, and C 9 - C 11 Alkyl poly glucoside (n = 1.4), eg. available as APG 300 from Henkel. (J) Poly(oxyalkylene) fatty alkyl ether , having the structure (11), R 12 ― O ― (Z 12 O) p H where R 12 represents a C 8 to C 18 alkyl group; Z 12 is a C 2 or C 3 alkylene group; and p is an integer from 1 to 10. Preferred examples for a poly(oxyalkylene)-fatty alkyl ether having the structure (11) are (PEG)-6 lauryl ether and (PEG)-6 myristyl ether. A mixture of (PEG)-6 C 12 -C 15 is available as Dobanol 91-6 from Shell Chemicals. (K) N-substituted Betaines , having the structure (12); where Z 13 represents (i) a C 10 to C 18 alkyl group; or (ii) a R 13 CO - NH - (CH 2 ) 3 group, where R 13 CO represents a C 10 to C 18 acyl group. Preferred examples for N-substituted Betaines having the structure (12) include: Lauryl dimethyl betaine, eg. available as Empigen BB from Albright & Wilson, and Cocoamidopropyl betaine, eg. available as Tegobetaine L7F from Goldschmidt. ( L ) Sultaines , having the structure (13); where Z 14 represents a C 10 to C 18 alkyl group or a C 10 to C 18 acyl amido group. A preferred example for a Sultaine having the structure (13) is Cocoamidopropyl hydroxysultaine, eg. available as Cycloteric BET-CS from Alcolac. ( M ) Alkylamphocarboxylates , having the structure (14); where R 15 CO represents a C 10 to C 18 acyl group; Z 15 and Y 15 are independently from each other chosen from H, CH 2 CH 2 OH or (CH 2 ) r COO - ; r is 1 or 2; and M 15 is as M 1 in structure (1). Preferred examples for Alkylamphocarboxylates having the structure (14) include: Cocoamphoglycinate eg. available from GAF, Wheatgerm amphodiglycinate, Cocamphodipropionate, eg. available as Mirataine C2MS from Rhone Poulenc, Caprylamphodipropionate, eg. available as Miranol S2MSF from Rhone Poulenc, Cocoamphoacetate, eg. available as Nissan Anon GLM-R from Nippon Oils & Fats. Water The cleansing composition according to the invention also comprises water. The water will normally be present in an amount of up to 85%, preferably from 10 to 85% by weight of the composition. Optional Ingredients The cleansing composition according to the invention can also comprise optional ingredients to modify the physical or chemical characteristics of the composition, eg. product form, foaming properties, pH-value or shelf life. Examples for ingredients which can be included in the compositions according to the invention are: Emollients, such as: [PEG]-20 Corn Glycerides, [PEG]-60 Corn Glycerides, [PEG]-20 Almond Glycerides, [PEG]-60 Almond Glycerides, [PEG]-12 Palm Kernel Glycerides, [PEG]-45 Palm Kernel Glycerides, [PEG]-20 Evening primrose Glycerides, [PEG]-60 Evening Primrose Glycerides, Ethoxylated (EO)-20 methyl glucoside, also referred to as Methyl gluceth-20 Propoxylated (EO)-10 methyl glucoside. A group of preferred emollients are poly (oxyalkylene) glycerides mono-substituted with a C 10 to C 18 alkyl group and having up to 20 C 2 to C 3 oxyalkylene moieties per molecule of the glyceride, as an average value. Especially preferred emollients are Polyoxyalkylene methyl glucosides having, as an average value, up to 20 C 2 - C 3 oxyalkylene moieties per molecule glucoside. These emollients are very beneficial as they impart a soft feeling to the skin and support the ability of the skin to retain moisture. Examples for such Polyoxyalkylene methyl glucosides are available as Glucam E-20 and Glucam P10, respectively, from Amerchol. Humectants, such as glycerine, sorbitol, sodium 2-pyrrolidone-5-carboxylate, soluble collagen, gelatine, ethoxylated (EO)-20 methyl glucoside, and propoxylated (EO)-10 methyl glucoside. Preservatives, such as ethanol, benzoic acid, sodium benzoate, sorbic acid, alkali metal halides; PH controlling agents, such as Sodium hydroxide, Citric acid, Triethanolamine, Potassium hydroxide, Amino Sorbitol. The pH controlling agents are preferably present in an amount sufficient to adjust the composition to a pH value in the range of 5.5 to 8.5. Propellants, such as fluorochloro hydrocarbons, propane, butane, isobutane, dimethyl ether, carbon dioxide, nitrous oxide; Foam modifying agents, such as cationic polymers, especially quaternised ammonium hydroxy ethyl cellulose polymers, eg. available as polyquaternium-24 or polyquaternium-10. These polymers make the foam creamier and richer. Further Optional Ingredients The composition according to the invention can also contain other optional agents, that is ingredients other than the main ingredients already defined which are conventionally employed in cleansing compositions, such as thickeners. USE OF THE COMPOSITION The cleansing composition according to the invention is primarily intended as a personal washing product for cleansing the face. It can also be used for washing the hair as well as the whole body. The composition according to the invention is preferably used as facial cleanser, facial wash foam, hair shampoo, body shampoo, bath foam or shaving cream. Due to the high detergency provided by the composition it is also possible to use it in non-cosmetic applications, such as a household cleanser, carpet cleanser or detergent for tableware. The following procedure is an example for the use of the cleansing composition according to the invention; a small quantity, for example from 1 to 5ml, of the composition is either rubbed between the hands, together with water together to form a foam which is then used for washing or applied via a sponge to the area to be cleansed, or the foam is generated directly on that area. The foam is subsequently rinsed away with clean water. The cleansing composition according to the invention can take the form of a liquid or gel, intended to be dispensed from a capped container such as a bottle, roll-on applicator or tube, or a pump-operated or propellant-driven aerosol dispenser. The composition can also take the form of a solid, such as a stick or a bar or tablet intended to be used for washing instead of a conventional soap bar. Foaming Properties of the Composition Although the composition according to the invention does not include harsh surfactants, as are found in conventional cleansing compositions, its foaming power is excellent. This is shown by the foam-heights measured by the Foam-Height Test described hereinafter. Foam-Height Test The test-method which has been used to assess the foaming power of the cleansing compositions according to the invention is the ASTM D 1173-53 test, also referred to as Ross-Miles test, and described in J Ross and G D Miles, American Society for Testing Materials, 1953, pages 644-646. The test has been carried out at a temperature of 20°C by using an aqueous test solution of 0.3% by weight acyl lactylate and 0.1% by weight co-surfactant. This is a realistic concentration of the cleansing composition according to the invention when used by the consumer, eg. when topically applied on the face or body together with water to generate the desired foam. The pH value of the test solution has been adjusted to a pH of 7.5 by addition of aqueous sodium hydroxide solution. The following Table I shows the foam heights obtained by using various cleansing compositions according to the invention. In any case the acyl laactylate was a mixture of 70% by weight sodium lauroyl lactylate and 30% by weight myristoyl lactylate. This mixture is available under the trade name Pationic 138C from RITA Patterson. The foam height measured for this mixture without added co-surfactant is quoted as experiment (27). Co-surfactant Foam-height (mm) (1) Sodium N-methyl-N-cocoyl taurate 193 (2) Sodium N-methyl-N-lauroyl taurate 198 (3) Sodium N-methyl-N-myristoyl taurate 193 (4) Triethanolammonium N-cocoyl sarcosinate 210 (5) Sodium N-cocoyl glutamate 165 (6) Sodium cocoyl isethionate 185 (7) Sodium cocoyl [PEG]-10 acetate 180 (8) Sodium tridecyl [PEG]-3 acetate 155 (9) Sodium N-lauroyl alaninate 172 (10) Sodium lauryl sulphoacetate 194 (11) Sodium cocoyl amido [EO]-3 sulphate 190 (12) Disodium lauroyl amido [EO]-2 to 3 sulphosuccinate 148 (13) Disodium lauryl sulphosuccinate 175 (14) Disodium lauryl [PEG]-2 to 3 sulphosuccinate 170 (15) Mixture of Disodium lauryl/myristyl [PEG]-2 sulphosuccinate 180 (16) Sodium cocoyl mono glyceride sulphate 158 (17) Decyl polyglucoside ( = 1.44) 170 (18) C 9 -C 11 Alkyl polyglucoside ( = 1.4) 172 (19) [PEG]-6 C 12 -C 15 fatty alkyl ether 168 (20) N-lauryl dimethyl betaine 180 (21) Cocoamidopropyl betaine 170 (22) Cocoamphodipropionate 165 (23) Cocoamphoacetate 173 (24) - 125 It can be seen from experiment (24) that all the co-surfactants used in experiments (1)-(23) enhance the foam height of the acyl lactylate mixture Pationic 138C to some degree. In particular, taurates having the structure (2), sarcosinates having the structure (9), sulphosuccinates having the structures (7a) or (7b) and isethionates having the structure (3) are capable of increasing the foam height drastically. The components of the composition and their amounts are chosen in such a manner that the cleansing composition according to the invention has a foam height of more than 130mm, as measured by the foam height test carried out under the conditions described above. Preferably the compositions according to the invention have a foam height of more than 150mm, more preferred more than 170mm and most preferred more than 190mm. The superiority of the compositions according to the invention as compared to conventional products is shown by the foam heights stated in the following Table II for facial wash foams based on conventional surfactant systems. Again the Ross-Miles test under the above defined conditions was carried out to assess the respective foam heights. The test solutions were aqueous solutions containing the conventional product at a concentration of 1.0% by weight. The percentages given below for the ingredients of the surfactant systems are based on the weight of the respective product. Surfactant-System Foam Height (mm) (1) 14% cocoyl isethionate 99 (2) 37% mixture of C 18 /C 16 /C 14 /C 12 potassium soaps 76 (3) 36% mixture of C 14 /C 12 triethanolammonium soaps 52 (4) 19% Fatty acyl glutamate, 70 2% Fatty acyl sarcosinate, 4% C 14 /C 12 potassium soap, (5) 10% nonionic surfactant, 114 4% ether sulphate, 1.6% Fatty acyl sarcosinate (6) 30% C 18 /C 14 /C 12 potassium soaps 54 5% Sodium lauroyl glutamate (7) 10% Sodium lauryl ethersulphate 128 4% Cocamidopropyl betaine The above data clearly show that the compositions according to the invention give a much higher foam height than cleansing compositions based on conventional surfactant systems. Although the cleansing compositions according to the invention comprise high amounts of acyl lactylate, namely from 10 to 30% by weight an excellent foaming power is achieved, as is shown by the data in Table I. This is clearly in contrast to the teaching of the prior art as disclosed in EP-A-224 796 (Kao) that only amounts of less than 5% by weight of acyl lactylate should be included in surfactant systems to obtain mild and high foaming cleansing compositions. The data given in Table III below show the greater foaming power obtainable by compositions embodying the present invention compared to the prior art described in EP-A-224796. Examples (i) to (viii) in table III contain the same lactylates in the same amounts as corresponding Examples 2 to 9 in Table 7-1 of EP-A-224796. In each of cases (i) to (viii) a 7:3 mixture of triethanolamine mono:di lauryl phosphate was present at a level of 15 wt%, triethanolamine was added to adjust the pH to 7.5 and demineralised water was used to 100 wt%. As shown in Table III in each case the lactylate content is less than 5wt% and the foam height, as measured by the Ross-Miles test described above, is less than 130mm. Lactylate present Foam height (mm) (i) 0.5wt% stearoyl lactylate 100 (ii) 2.0wt% stearoyl lactylate 100 (iii) 0.5wt% iso-stearoyl lactylate 105 (iv) 2.0wt% iso-stearoyl lactylate 100 (v) 0.5wt% lauroyl lactylate 105 (vi) 2.0wt% lauroyl lactylate 115 (vii) 0.5wt% myristoyl lactylate 105 (viii) 2.0wt% myristol lactylate 109 In contrast Table IV below gives the foaming power of compositions embodying the present invention. The foaming power was measured by the Ross Miles test described above. In each case the solutions were adjusted to pH 7.5 by addition of 20% aqueous solution of NaOH and were made up to 100% with demineralised water. Surfactant System Foam Height (mm) (ix) 17wt% 1:1 Sodium C 10 :C 12 lactylate 135 2wt% Sodium N-myristoyl-N-methyl laurate (x) 10wt% 7:3 Sodium C 12 :C 14 lactylate 135 5wt% Disodium lauryl/myristoyl sulphosuccinate (xi) 17wt% 7:3 Sodium C 12 :C 14 lactylate 150 2wt% Decyl polyglucoside (xii) 17wt% 7:3 Sodium C 12 :C 14 lactylate 150 2wt% Sodium cocoyl isethionate As can be seen from Table IV each surfactant system embodying the present invention had a foam height above 130mm. The superiority of the cleansing compositions according to the invention to conventional compositions comprising less than 10% by weight of acyl lactylate is demonstrated by the data given in the following Table V. The foam heights were again measured by the Ross-Miles Test conducted under the conditions as defined above. All percentages given are based on the weight of the respective test solution. All test solutions were adjusted to a pH value of 7.5 by addition of aqueous NaOH solution. Test Solutions Foam Height (mm) (A) 5% lauroyl dilactylic acid 112 5% Triethanolammonium laury sulphate 5% Coconut diethanolamide to 100% demineralised water (B) 75% lauroyl dilactylic acid 119 5% Triethanolammonium laury sulphate 3% Coconut diethanolamide to 100% demineralised water (C) 9% lauroyl dilactylic acid 116 1% Triethanolammonium laury sulphate 1% Coconut diethanolamide to 100% demineralised water (D) 9% lauroyl dilactylic acid 104 3% Triethanolammonium laury sulphate 1% Coconut diethanolamide to 100% demineralised water (E) 10% Sodium lauroyl/myristol lactylate(Pationic 138 C) 141 4% Sodium cocoyl isethionate 1% Cocoampho carboxy glycinate to 100% demineralised water (F) 12% Sodium lauroyl/myristol lactylate (Pationic 138 C) 136 1.5% Sodium N-lauroyl sarcosinate 1.5% Sodium N-methyl-N-cocoyl taurate to 100% demineralised water (G) 15% Sodium lauroyl/myristol lactylate (Pationic 138 C) 136 2% Sodium laurylamide [EO]-3 sulphate to 100% demineralised water The above data show that, although the compositions according to the invention (E) to (G) are used in amounts of 10% by weight or more, they foam much better than the conventional compositions (A) to (D). The following examples further illustrate the invention by giving conventionally prepared formulations for different types of cleansing compositions. EXAMPLES Example 1 - Facial Cleanser wt % Potassium dodecanoyl monolactylate 15.00 Potassium dodecanoyl dilactylate 15.00 Disodium lauryl sulphosuccinate 7.00 Glycerol (Humectant) 5.00 Sodium chloride (Thickener) 4.20 Methyl gluceth-20 (Humectant/Emollient) 3.00 Polyquaternium 10 (Foam modifier) 0.40 Ethyleneglycol monostearate (Thickener) 0.40 Preservative 0.30 Fragrance 0.30 Citric acid to pH 7.0-7.5 Distilled water to 100.00 Foam height = 153mm Example 2 - Mild Facial Cleanser wt % Sodium myristoyl dilactylate 20.00 Sorbitol (Humectant) 9.00 Sodium cocoyl isethionate 7.00 Cocoamidopropyl hydroxysulphobetaine 4.00 Polyoxyethylene [EO]-20 sorbitan monolaurate (Thickener) 3.00 Hydroxypropyl methylcellulose (Thickener) 0.20 Preservative 0.20 Fragrance 0.10 Citric acid to pH 6.0-6.5 Distilled water to 100.00 Foam height = 162mm Example 3 - Mild Facial Cleanser for Sensitive Skin wt % Lauroyl dilactylic acid 20.0 Sodium N-methyl-N-myristoyl taurate 6.00 Cocoamphoacetate 3.50 Glycerol (Humectant) 9.00 Diglycerol (Humectant) 1.00 PEG-20 almond glycerides (Emollient) 5.00 Polyquaternium 24 (Thickener, Foam Modifier) 0.40 Sodium Hydroxide (aq. soln.) to pH 6.0-6.5 Distilled water to 100.00 Foam height = 150mm Example 4 - Liquid Hand Soap wt % Lauroyl dilactylic acid 7.50 Palmitoyl dilactylic acid 7.50 Triethanolammonium N-lauroyl glutamate 9.00 Cocoamidopropyl betaine 4.00 Propyleneglycol hydroxy isostearate (Thickener) 1.00 Trisodium citrate (Thickener) 7.00 Preservative 0.26 Fragrance 0.15 Triethanolamine to pH 7.0-7.3 Distilled water to 100.00 Foam height = 144mm Example 5 - Anti-Acne Facial Cleansing Scrub Gel wt % Sodium decanoyl monolactylate 18.00 Sodium N-cocoyl sarcosinate 6.00 Benzoyl peroxide (70% aq.soln.) 14.30 Polyoxyethylene (PEG)-20 cetyl ether (Thickener, Emulsifier) 10.00 Magnesium aluminium silicate (Thickener) 1.00 Disodium ethylenediamine tetraacetate (Chelating Agent) 0.20 Sodium Hydroxide to pH 7.0-7.5 Distilled water to 100.00 Foam height = 135mm Example 6 - Hair Shampoo wt % Triethanolammonium dodecanoyl monolactylate 21.00 Sodium lauryl (PEG)-10 acetate 4.00 Cocoamphodipropionate 3.00 Propylene glycol (Humectant) 2.50 Sodium chloride (Thickener) 1.20 Preservative 0.20 Fragrance 0.20 Citric acid to pH 6.0-6.5 Distilled water to 100.00 Foam height = 158mm Example 7 - Conditioning Shampoo wt % Potassium lauroyl monolactylate 11.00 Sodium lauroylamide polyoxyethylene (EO)-3 sulphate 4.50 Lauryldimethyl betaine 4.00 Potassium chloride (Thickener) 2.50 Dimethicone copolyol (Conditioning agent) 0.50 Preservative 0.17 Fragrance 0.11 Dye 0.02 Citric acid to pH 6.5-7.0 Distilled water to 100.00 Foam height = 170mm Example 8 - Antidandruff Shampoo wt % Ammonium decanoyl monolactylate 14.00 Ammonium decanoyl dilactylate 4.00 Ammonium lauryl sulphoacetate 5.00 Zinc Pyrithione (48% aq.soln.) (Anti-fungal agent) 2.10 Hydroxypropyl methylcellulose 1.25 Magnesium aluminium silicate (Thickener) 1.00 Preservative 0.36 Fragrance 0.20 Dye 0.03 Citric acid to pH 7.0-7.3 Distilled water to 100.00 Foam height = 150mm Example 9 - Body Shampoo wt % Dodecanoyl dilactylic acid 13.00 Sodium N-cocoyl alaninate 4.00 Lauroamphoglycinaate 4.00 (PEG) -80 sorbitan laurate (Thickener) 3.30 Disodium ethylenediamine tetraacetate 0.20 Preservative 0.10 Fragrance 0.05 Dye 0.01 Citric acid to pH 7.0-7.5 Distilled water to 100.00 Foam height = 164mm Example 10 - Mild Body Shampoo wt % Triethanolammonium lauroyl monolactylate 7.50 Triethanolammonium myristoyl monolactylate 7.50 Disodium lauryl (PEG) -2.5 sulphosuccinate 10.00 Cocoamidopropyl betaine 5.00 Glycerol 5.00 Polyoxyethylene (PEG) -45 monostearate (Thickener) 2.00 Preservative 0.35 Fragrance 0.35 Citric acid to pH 7.0-7.5 Distilled water to 100.00 Foam height = 165mm Example 11 - Liquid Body Shampoo wt % Potassium decanoyl monolactylate 10.00 Potassium decanoyl dilactylate 10.00 Decyl polyglucoside (n=1.44) 5.00 Glycerol 5.00 Trisodium citrate dihydrate (Thickener) 1.50 Sodium carboxymethyl cellulose (Thickener) 1.00 Citric acid to pH 7.0-7.5 Distilled water to 100.00 Foam height = 138mm Example 12 - Aerosol Body Shampoo wt % Sodium decanoyl monolactylate 10.00 Sodium decanoyl dilactylate 10.00 Decyl polyglucoside (n=1.44) 5.50 Glycerol 2.00 Trisodium citrate dihydrate 1.50 Sodium carboxymethyl cellulose 1.00 Preservative 0.35 Fragrance 0.35 Citric acid to pH 7.0-7.5 Distilled water to 100.00 Foam height = 140mm 95% by weight of the solution obtained by mixing the above ingredients was combined with 5% by weight propellant and then sealed into a container. Example 13 - Bath Foam Concentrate wt % Lauroyl monolactylic acid 15.00 Lauroyl dilactylic acid 10.00 Cocoamphopropionate 5.00 Sorbitol 9.00 Sodium chloride 6.00 Sodium carboxymethyl cellulose (Thickener) 1.00 Preservative 0.30 Fragrance 0.60 Chamomile distillate (Anti-inflammatory agent) 1.00 Aminosorbitol to pH 7.0-7.5 Distilled water to 100.00 Foam height = 165mm Example 14 - Mild Bath Foam wt % Sodium myristoyl monolactylate 18.00 Sodium myristoyl dilactylate 6.00 Sodium lauroyl monoglyceride sulphate 5.00 Cocoamidopropyl hydroxysulphobetaine 4.00 Preservative 0.20 Fragrance 1.00 Citric acid to pH 7.2-7.7 Distilled water to 100.00 Foam height = 149mm Example 15 - Conditioning Bubble Bath wt % Triethanolammonium decanoyl monolactylate 20.00 Cocoamphodiacetate 5.00 Polyoxyethylene (PEG)-20 cetyl ether 4.00 Polyoxyethylene (PEG) -50 stearyl ether 4.00 Lauryl methyl gluceth-10 hydroxypropyl diammonium chloride (Conditioner) 0.50 Polyquaternium 24 (Thickener) 0.40 Citric acid to pH 7.0-7.5 Distilled water to 100.00 Foam height = 151mm Example 16 - Cleansing Bar wt % Sodium lauroyl dilactylate 20.00 Sodium myristoyl dilactylate 15.00 Sodium N-cocoyl glutamate 15.00 Sodium N-stearoyl aspartate 10.00 Glycerol 8.00 Diglycerol 8.00 Preservative 0.30 Fragrance 0.60 Pigment 0.10 Distilled water to 100.00% Foam height = 175mm Example 17 - Facial wash Foam %w/w Sodium lauroyl lactylate 14.00 Sodium myristoyl lactylate 6.00 Sodium lauryl ethoxy phosphate 6.00 Disodium lauroyl amido ethoxy sulphosuccinate 2.00 Disodium wheatgerm amido PEG-2 sulphosuccinate 2.00 Polyquaternium-24 0.40 Glycerol (humectant) 10.00 (PEG) -12 palm kernel glycerides (emollient) 5.00 Sodium hydroxide solution to pH 6.8-7.0 Distilled water to 100.00% Foam height = 190mm Example 18 - Facial Wash Foam %w/w Sodium lauroyl lactylate 14.00 Sodium myristoyl lactylate 6.00 Sodium cocoyl isethionate 6.00 wheatgerm amphodiacetate 2.00 Cocoamphocarboxy glycinate 2.00 Polyquaternium-24 0.40 Glycerol (humectant) 10.00 (PEG) -40 almond glycerides (emollient) 5.00 Sodium hydroxide solution to pH 6.8-7.0 Distilled water to 100.00% Foam height = 180mm Example 19 - Facial wash foam wt % Sodium lauroyl lactylate 14.00 Sodium myristoyl lactylate 6.00 Sodium cocoyl isethionate 6.75 Monolauryl phosphoric acid 2.40 Dilauryl phosphoric acid 0.60 Triethanolammonium N-cocoyl sarcosinate 1.00 Glycerol 10.00 Polyquaternium 10 0.40 Sodium hydroxide solution to pH 6.8-7.0 Distilled water to 100.00% Foam height = 185mm Example 20 - Facial wash foam wt % Sodium lauroyl lactylate 14.00 Sodium myristoyl lactylate 6.00 Sodium cocoyl isethionate 6.00 Sodium N-methyl-N-cocoyl taurate 3.00 Sodium N-cocoyl sarcosinate 1.00 Glycerol 10.00 Polyquaternium 10 0.40 Sodium hydroxide solution to pH 6.8-7.0 Distilled water to 100.00% Foam Height - 190mm

Claims: A cleansing composition which comprises, in addition to water, (a) from 10 to 35% by weight of one or more acyl lactylate(s) of the following structure (1) where R 1 CO represents a C 6 to C 16 acyl radical; a is an integer from 1 to 3; M 1 represents hydrogen or a counterion chosen from alkali metal, ammonium or a substituted ammonium group having one or more C 1 to C 3 alkyl or hydroxy alkyl group(s); and (b) from 5 to 25% by weight of one or more co-surfactant(s) chosen from the following compounds (A) to (O): (A) N-methyl-N-acyl taurates of the following structure (2) where R 2 CO represents a C 10 to C 18 acyl group; and M 2 is as M 1 in structure (1); (B) Acylisethionates of the following structure (3) R 3 CO ― OCH 2 CH 2 ― SO 3 M 3 where R 3 CO represents a C 10 to C 18 acyl group; and M 3 is as M 1 in structure (1); (C) Alkylesters of ω-sulphonated carboxylic acids of the following structure (4) where R 4 represents a C 10 to C 18 alkyl group; M 4 is as M 1 in structure (1); and (b) is an integer from 1 to 3; (D) Fatty acylamido polyoxyethylene sulphates of the following structure (5) R 5 CO ― NH ― (CH 2 CH 2 O) c ― SO 3 M 5 where R 5 CO represents a C 10 to C 18 acyl group; M 5 is as M 1 in structure (1); and c is an integer from 1 to 10; (E) Fatty acid polyglyceride sulphates of the following structure (6) R 6 CO ― O ― (CH 2 - CHOH - CH 2 O) d ― SO 3 M 6 where R 6 CO represents a C 10 to C 18 acyl group; M 6 is as M 1 in structure (1); and d is an integer from 1 to 4; (F) Mono substituted sulphosuccinates of the following structures (7a) or (7b) where Z 7 is chosen from the following groups (i) to (iii): (i) R a CO - NH - (CH 2 CH 2 O) e -, where R a CO represents a C 10 to C 18 acyl group; and e is an integer from 1 to 10; (ii) R b - O - (CH 2 CH 2 O) f -, where R b represents a C 10 to C 18 alkyl group; and f is an integer from 1 to 10; (iii) R c - O -, where R c represents a C 10 to C 18 aklyl group; and X 7 and Y 7 are independently from each other chosen from the counterions represented by M 1 in structure (1); (G) Alkyl poly(ethylene glycol) acetates of the following structure (8) where R 9 represents a C 10 to C 18 alkyl group; M 9 is as M 1 in structure (1); and h is an integer from 1 to 10; (H) Salts of N-acyl α-amino acids of the following structure (9) where R 10 CO represents a C 10 to C 18 acyl group; Z 10 represents H or C 1 to C 2 alkyl; Y 10 represents H, C 1 to C 3 alkyl or C 1 to C 3 alkyl substituted with a COOH group; and M 10 is chosen from the counterions represented by M 1 in structure (1); (I) Alkyl polyglucosides of the following structure (10) where R 11 represents a C 10 to C 14 alkyl group; and n is an integer from 1 to 3; (J) Poly(oxyalkylene) fatty alkyl ether of the following structure (11) R 12 ― O ― (Z 12 O) p H where R 12 represents a C 8 to C 18 alkyl group; Z 12 is a C 2 or C 3 alkylene group; and p is an integer from 1 to 10; (K) N-substituted betaines of the following structure (12) where Z 13 represents (i) a C 10 to C 18 alkyl group; or (ii) a R 13 CO - NH - (CH 2 ) 3 group, where R 13 CO represents a C 10 to C 18 acyl group; (L) Sultaines of the following structure (13) where Z 14 represents a C 10 to C 18 alkyl group or a C 10 to C 18 acyl amido group; (M) Alkyl amphocarboxylates of the following structure (14) where R 15 CO represents a C 10 to C 18 acyl group; Z 15 and Y 15 are independently from each other chosen from H, CH 2 CH 2 OH or (CH 2 ) r COO - ; r is 1 or 2; and M 15 is as M 1 in structure (1); the composition having a foam height of more than 130mm, as measured by the foam height test described herein. A composition according to claim 1, which has a foam height of more than 150mm. A composition according to claim 1, which has a foam height of more than 170mm. A composition according to claim 1, which has a foam height of more than 190mm. A composition according to claim 1, in which the acyl group R 1 CO in structure (1) represents a C 10 to C 14 acyl radical. A composition according to claim 1, in which the acyl lactylate is present in an amount from 15 to 30% by weight. A composition according to claim 1, in which the co-surfactant is present in an amount of 10 to 25% by weight. A composition according to claim 1, which comprises a quaternised ammonium hydroxy ethyl cellulose polymer. Method of cleansing skin or hair using a composition according to claim 1.

Inventors: CARTER PETER, HAGAN DESMOND BERNARD, CARTER, PETER, HAGAN, DESMOND BERNARD, CARTER, PETER, UNILEVER RESEARCH, HAGAN, DESMOND BERNARD, UNILEVER RESEARCH
Applicants: UNILEVER NV, UNILEVER PLC, UNILEVER N.V.
Application year: 1993
Main classification: A61K7
IPC codes: C11D1, C11D3, C11D17, A61Q1, A61Q19, C07C309, A61K8, C07C69, A61Q5, C07F9