Relation to the manufacture of personal cleansing compositions

Abstract

The invention relates to a method of making solid cleansing compositions which comprise a non-soap anionic surfactant, a carrier, an emulsifier and water. The method entails preparing an emulsion of the components at an elevated temperature using excess water and subjecting the emulsion to cooling and solidification, wherein the water content is reduced. The invention further relates to the emulsions and to the novel solid cleansing compositions formed therefrom.

Claims

1. A method of making a solid cleansing composition, the composition comprising: a. at least 15% wt of a non-soap anionic surfactant having a melting point of at least 45° C.; b. at least 10% wt of a carrier having a melting point of at least 45° C.; c. at least 3% wt of an emulsifier; and d. at least 7% wt water; wherein the composition is a solid throughout the range from 0° C. to 40° C.; wherein the composition does not contain soap; wherein the carrier (b) is a triglyceride; wherein the emulsifier, component (c), has an HLB value of up to 12; wherein when two or more emulsifiers are present, the HLB is a weighted average taking into account the individual HLB values and amounts of the two or more emulsifiers; and wherein the method comprises: (i) preparing an emulsion containing the components (a) to (d), but with a greater mass of water present than in the solid cleaning composition, the temperature of the emulsion being at least 45° C., (ii) subjecting the emulsion to cooling and solidification, wherein the water content is reduced during the cooling and solidification to produce the solid cleansing composition having components (a) to (d) in the amounts defined.

2. The method as claimed in claim 1 wherein the emulsion is cooled and solidified to form particles of the solid cleansing composition.

3. The method as claimed in claim 1 wherein the emulsion at a temperature of at least 45° C. is a free-flowing liquid.

4. The method as claimed in claim 1 wherein the solid cleansing composition is soap-free.

5. The method as claimed in claim 1 wherein the mass of water initially present in the emulsion is at least 40% higher than the mass of water present in the solid cleansing composition.

6. The method as claimed in claim 1 wherein component (a) comprises a sulfate, sulfonate, amphoacetate, sulfoacetate, sulfosuccinate, phosphate or carboxylate non-soap anionic surfactant; selected in each case to have a melting point above 45° C.

7. The method as claimed in claim 1, wherein component (a) comprises an acyl isethionate.

8. The method as claimed in claim 1 wherein the non-soap anionic surfactant constitutes at least 20% wt and up to 60% wt of the solid cleansing composition.

9. The method as claimed in claim 1 wherein the carrier (b) comprises one or more of a wax, a triglyceride, a fatty acid or a fatty alcohol.

10. The method as claimed in claim 1, wherein the carrier (b) comprises a triglyceride of vegetal origin which has been hydrogenated to achieve saturation of substantially all fatty acid chains in the triglyceride, and whose fatty acid chains are residues of C.sub.8-C.sub.32 fatty acids.

11. The method as claimed in claim 10 wherein component (b) comprises at least of one of hydrogenated rapeseed oil, hydrogenated soybean oil, hydrogenated sunflower oil, hydrogenated palm oil, hydrogenated castor oil, hydrogenated safflower oil and hydrogenated peanut oil.

12. The method as claimed in claim 1 wherein the carrier (b) constitutes at least 15% wt and up to 40% wt of the solid cleansing composition.

13. The method as claimed in claim 1 wherein the emulsifier, component (c), has an HLB value of at least 6 and up to 12, wherein when two or more emulsifiers are present, the HLB is a weighted average taking into account the individual HLB values and amounts of the two or more emulsifiers.

14. The method as claimed in claim 1 wherein the emulsifier (c) is selected from sorbitan fatty acid esters, ethoxylated sorbitan fatty acid esters and glycerol or polyglycerol esters of fatty acids.

15. The method as claimed in claim 14 wherein the emulsifier (c) comprises glycerol or polyglycerol esters of C.sub.8-C.sub.24 fatty acids.

16. The method as claimed in claim 15 wherein the emulsifier, component (c), is the esterification reaction product of: A. a triglyceride, or a fatty acid, or a methyl ester of a fatty acid (or any combination thereof), and B. a polyhydric alcohol which comprises B1) a polyglycerol having at least 3 glycerol units, wherein the average molecular weight of the polyglycerol in component B1), having at least 3 glycerol units, is in the range 220-500 g/mol, and B2) glycerol and/or diglycerol.

17. The method as claimed in claim 1 wherein the emulsifier, component (c), constitutes at least 2% wt and up to 9% wt of the solid cleansing composition.

18. The method as claimed in claim 1 wherein water, component (d), constitutes at least 5% wt and up to 16% wt of the solid cleansing composition.

19. The method as claimed in claim 1 wherein the solid cleansing composition comprises: (a) at least 20% wt and up to 60% wt of a non-soap anionic surfactant having a melting point of at least 45° C.; (b) at least 20% wt and up to 60% wt of a carrier having a melting point of at least 45° C.; (c) at least 2% wt and up to 9% wt of an emulsifier; (d) at least 5% wt and up to 16% wt of water; wherein components (a) to (d) make up at least 70% and up to 100% of the weight of the solid cleansing composition.

20. A solid cleansing composition which comprises: (a) at least 15% wt of a non-soap anionic surfactant having a melting point of at least 45° C.; (b) at least 10% wt of a carrier having a melting point of at least 45° C.; (c) at least 3% wt of an emulsifier; and (d) at least 7% wt water; wherein the composition is a solid throughout the range from 0° C. to 40° C.; wherein the composition does not contain soap; wherein the carrier (b) is a triglyceride; wherein the emulsifier, component (c), has an HLB value of up to 12; and wherein when two or more emulsifiers are present, the HLB is a weighted average taking into account the individual HLB values and amounts of the two or more emulsifiers.

21. An emulsion for the preparation of a solid cleansing composition, wherein the composition is a solid throughout the range from 0° C. to 40° C., the emulsion comprising: (a) at least 20% wt and up to 50% wt of a non-soap anionic surfactant having a melting point of at least 45° C.; (b) at least 20% wt and up to 50% wt of a carrier having a melting point of at least 45° C.; (c) at least 2% wt and up to 9% wt of an emulsifier; and (d) at least 16% wt and up to 50 wt % water; wherein the emulsion does not contain soap; wherein the emulsion is at a temperature of at least 45° C.; wherein the emulsifier, component (c), has an HLB value of up to 12; wherein when two or more emulsifiers are present, the HLB is a weighted average taking into account the individual HLB values and amounts of the two or more emulsifiers; and wherein components (a) to (d) make up at least 70% and up to 100% of the weight of the emulsion.

22. The method as claimed in claim 1, wherein the solid cleansing composition is in the form of noodles, pellets, flakes or powder.

23. The method as claimed in claim 1, wherein the method comprises a step (iii) of consolidating the solid cleansing composition into a block, bar or tablet.

24. The method as claimed in claim 1, wherein the non-soap anionic surfactant constitutes at least 20% wt and up to 60% wt of the solid cleansing composition.

25. The method as claims in claim 1, wherein the solid cleansing composition comprises: a. at least 35% wt and up to 55% wt of a non-soap anionic surfactant having a melting point of at least 50° C.; b. at least 20% wt and up to 40% wt of a triglyceride having a melting point of at least 50° C.; c. at least 3% wt and up to 8% wt of an emulsifier; d. at least 8% wt and up to 12% wt of water; wherein components (a) to (d) make up at least 80% and up to 100% of the weight of the cleansing composition.

26. The solid cleansing composition according to claim 20, wherein the emulsifier, component (c), has an HLB value of at least 6 and up to 12; wherein when two or more emulsifiers are present, the HLB is a weighted average taking into account the individual HLB values and amounts of the two or more emulsifiers.

27. The solid cleansing composition according to claim 20, which comprises: a. at least 20% wt and up to 60% wt of a non-soap anionic surfactant having a melting point of at least 45° C.; b. at least 20% wt and up to 60% wt of a triglyceride carrier having a melting point of at least 45° C.; c. at least 3% wt and up to 9% wt of an emulsifier; d. at least 5% wt and up to 14% wt of water; wherein components (a) to (d) make up at least 70% and up to 100% of the weight of the solid cleansing composition; wherein the composition is a solid throughout the range from 0° C. to 40° C.; and wherein the solid cleansing composition has a completely or predominantly homogeneous microstructure.

28. The solid cleansing composition according to claim 20, wherein the solid cleansing composition is in the form of noodles, pellets, flakes or powder, or has been consolidated into the form of a block, bar or tablet.

Description

EXAMPLE 1

(1) The following ingredients were added in the amounts stated in the second column and remained in the final product in the amounts stated in the third column. Addition of the ingredients was in the order stated, starting with water.

(2) TABLE-US-00001 Ingredient As added % wt Final product % wt Water 25.0 9.5 PUREACT I-78 36.1 43.4 Glycerine 3.6 4.3 DISSOLVINE GL 47S 0.2 0.12 DUROSOFT PK-SG (emulsifier) 6.9 8.4 Hydrogenated sunflower oil 28.2 34.3

(3) DISSOLVINE GL 47S is a Trade Mark of Akzo Nobel of the Netherlands. It is a chelating agent, tetrasodium N, N-bis(carboxylatomethyl)-L-glutamate (GLDA).

(4) PUREACT I-78 is a Trade Mark of Innospec Performance Chemicals, of Ellesmere Port, UK. Its major component is sodium cocoyl isethionate (SCI), 83-89% wt; generally also having <1% wt water, <14% wt coconut fatty acid and 4-7% wt sodium isethionate.

(5) DUROSOFT PK-SG is a Trade Mark of Stephenson Group Limited of Leeds, UK. It is an ester of palm kernel oil and polyglycerol-4 (average Mw=250). DUROSOFT PK-SG has an HLB value of 8.8. A preparation of this product is given in WO2014170641.

(6) The sodium cocoyl isethionate (SCI) and the hydrogenated sunflower oil were melted and added to the water, which was at 90° C. The other ingredients were added in turn (the hydrogenated sunflower oil last) and the mass was worked for about 5 hours, whilst still molten. The emulsion, a readily flowable liquid, was then pumped twice through a needle plate having a 0.5 mm mesh and allowed to solidify as particles. During this phase of the processing, water was lost by evaporation and the water content was thereby reduced to approximately 9.5% wt on weight of the resulting solid cleansing composition. The particles were allowed to cool before being passed to a proprietary plodder. A typical plodder is the Duplex Model M400-2/M400-4 plodder manufactured by Mazzoni S.P.A. of Busto Arsizio, Italy. During plodding the temperature of the solid cleansing composition was maintained between 38° C. and 42° C. The billet produced by plodding, still at 38-42° C., was stamped into bars on chilled dies.

(7) The pH of the solid cleansing composition was 6-7 at 5% dilution, as measured by a commercial pH meter.

(8) The resulting products were of high quality, perfectly suitable for use.

EXAMPLE 2

(9) The following ingredients were added in the amounts stated in the second column and remained in the final product in the amounts stated in the third column. Addition of the ingredients was in the order stated, starting with water and the process parameters described for Example 1 were applied.

(10) TABLE-US-00002 Ingredient As added % wt Final product % wt Water 29.5 10 Glycerine 3.2 4.1 Pentesodium pentatate 0.05 0.06 (pentasodium DTPA - chelant) DEQUEST 2016 (1-Hydroxyl 0.05 0.06 ethylidene-1,1,-diphosphonic acid/HEDP-chelant) PUREACT I-78 36.0 45.9 DUROSOFT PK-SG (emulsifier) 3.2 4.1 Hydrogenated sunflower oil 28.0 35.7

(11) DEQUEST is a Trade Mark of Italmatch Chemicals S.P.A. of Genova, Italy.

(12) Preparation of cleansing tablets was as described in Example 1.

(13) The pH of the solid cleansing composition was 6-7 at 5% dilution, as measured by a commercial pH meter.

EXAMPLE 3

(14) The following ingredients were added in the amounts stated in the second column and remained in the final product in the amounts stated in the third column. Addition of the ingredients was in the order stated, starting with water.

(15) TABLE-US-00003 Ingredient As added % wt Final product % wt Water 23.5 10 Glycerine 3.5 4.1 Stearic acid 4.3 5.1 PUREACT I-78 43.5 51.1 DUROSOFT PK-SG (emulsifier) 2.6 3.1 Cocamidopropyl betaine (CAPB) 4.3 5.1 Glyceryl monostearate (GMS) 4.3 5.1 Hydrogenated sunflower oil 13.9 16.4

(16) Preparation of cleansing tablets was as described in Example 1.

(17) The pH of the cleansing composition was 6-7 at 5% dilution, as measured by a commercial pH meter.

(18) The resulting tablets were quite soft but still suitable for use.

EXAMPLE 4

(19) The following ingredients were added in the amounts stated in the second column and remained in the final product in the amounts stated in the third column. Addition of the ingredients was in the order stated, starting with water.

(20) TABLE-US-00004 Ingredient As added % wt Final product % wt Water 15.6 10 Glycerine 2.6 2.8 Monopropylene glycol (MPG) 6.1 6.5 PUREACT I-78 34.8 37.1 Disodium lauryl sulphosuccinate 7.0 7.4 (DSLSS) DUROSOFT PK-SG (emulsifier) 3.5 3.7 Hydrogenated sunflower oil 30.4 32.5

(21) Preparation of cleansing tablets was as described in Example 1.

(22) The pH of the cleansing composition was 6-7 at 5% dilution, as measured by a commercial pH meter.

(23) The resulting tablets were slightly too uneven in their dissolution to be regarded as optimal (“somewhat “gritty”, in the terminology used in the art) but were still suitable for use.

EXAMPLE 5

(24) The following ingredients were added in the amounts stated in the second column and remained in the final product in the amounts stated in the third column. Addition of the ingredients was in the order stated, starting with water.

(25) TABLE-US-00005 Ingredient As added % wt Final product % wt Water 18.7 10 Glycerine 2.6 2.8 Monopropylene glycol (MPG) 4.3 4.7 PUREACT I-78 34.2 37.9 Disodium lauryl sulphosuccinate 6.8 7.6 (DSLSS) DUROSOFT PK-SG 3.4 3.8 (emulsifier) Glyceryl monostearate (GMS) 3.0 3.3 Hydrogenated sunflower oil 14.1 15.6 C16-C18 linear alcohols 12.8 14.2 (NAFOL 1618)

(26) NAFOL is a trade mark of Sasol of Sandton, South Africa.

(27) Preparation of cleansing tablets was as described in Example 1.

(28) The pH of the cleansing composition was 6-7 at 5% dilution, as measured by a commercial pH meter.

(29) The resulting tablets were quite soft but still suitable for use.

EXAMPLE 6

(30) The following ingredients were added in the amounts stated in the second column and remained in the final product in the amounts stated in the third column. Addition of the ingredients was in the order stated, starting with water.

(31) TABLE-US-00006 Ingredient As added % wt Final product % wt Water 25.5 10 Glycerine 3.4 4.1 Diethylenetriamine pentaacetic 0.05 0.06 acid (VERSENEX-chelant) DEQUEST 2016 (chelant) 0.05 0.06 PUREACT I-78 40.1 48.4 Sorbitan monolaurate (SPAN 20) 3.4 4.1 Hydrogenated sunflower oil 27.6 33.3

(32) VERSENEX is a Trade Mark of Dow Chemicals of Auburn, Mich., USA.

(33) SPAN 20 is a Trade Mark of Croda International, of Yorkshire, UK.

(34) SPAN 20 has an HLB value of 8.6.

(35) Preparation of cleansing tablets was as described in Example 1.

(36) The pH (20%) of the cleansing composition was 6-7 at 5% dilution, as measured by a commercial pH meter.

(37) The resulting tablets were of high quality, perfectly suitable for use.

EXAMPLE 7

(38) The following ingredients were added in the amounts stated in the second column and remained in the final product in the amounts stated in the third column. Addition of the ingredients was in the order stated, starting with water.

(39) TABLE-US-00007 Ingredient As added % wt Final product % wt Water 25.5 10 Glycerine 3.4 4.1 Diethylenetriamine pentaacetic 0.05 0.06 acid (VERSENEX chelant) DEQUEST 2016 (chelant) 0.05 0.06 PUREACT I-78 40.1 48.3 Glyceryl stearate 2.1 2.5 Polyoxyethylene (20) sorbitan 1.3 1.6 monolaurate (Polysorbate 20) Hydrogenated sunflower oil 27.6 33.3

(40) Polysorbate 20 has a HLB value of 16.7. Glyceryl stearate has an HLB value of 3.8. The weighted average of these emulsifiers is calculated by the equation given above as 8.8.

(41) Preparation of cleansing tablets was as described in Example 1 except that during the processing small quantities of water were added to keep the foam down.

(42) The pH (20%) of the cleansing composition was 6-7 at 5% dilution, as measured by a commercial pH meter.

(43) The resulting tablets were softer than we would regard as optimal but still suitable for use.