IMPROVEMENTS IN RELATION TO PERSONAL CLEANSING COMPOSITIONS

Abstract

The invention relates to solid personal cleansing compositions which comprise a non-soap anionic surfactant, a carrier, an emulsifier, a humectant and water. The method entails preparing an emulsion of the components at an elevated temperature and cooling the emulsion to produce a block which can be re-melted and additised with colour, fragrance by downstream processors. The invention further relates to the emulsions and to methods for preparing the cleansing compositions.

Claims

1. A solid cleansing composition, the composition comprising: (a) at least 12% wt of a non-soap anionic surfactant having a melting point of at east 45° C.; (b) at least 8% wt of a carrier having a melting point of at least 45° C.; (c) at least 3% wt of an emulsifier; (d) at least 8% wt of a humectant; and (e) at least 8% wt water; wherein the composition is a solid throughout the range from 0° C. to 40° C.

2. The solid cleansing composition as claimed in claim 1 wherein the composition may be melted at a temperature above 45° C. and re-solidified at a temperature of 45° C. or below.

3. The solid cleansing composition as claimed in claim 1 wherein the solid cleansing composition does not contain soap or starch.

4. The solid cleansing composition as claimed in claim 1 wherein the non-soap anionic surfactant 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.

5. The solid cleansing composition as claimed in claim 4 wherein the non-soap anionic surfactant comprises an acyl isethionate.

6. The solid cleansing composition as claimed in claim 1 wherein the non-soap anionic surfactant constitutes at least 15% wt and up to 40% wt of the solid cleansing composition.

7. The solid cleansing composition as claimed in claim 1 wherein the carrier comprises one or more of a wax, a triglyceride, a fatty add or a fatty alcohol.

8.-9. (canceled)

10. The solid cleansing composition as claimed in claim 1 wherein the carrier constitutes at least 10% wt and up to 32% wt of the solid cleansing composition

11. The solid cleansing composition as claimed in claim 1 wherein the emulsifier has an HLB value of at least 6 and up to 12; and preferably at least 8 and up to 10.

12. The solid cleansing composition as claimed in claim 1 wherein the emulsifier is selected from sorbitan fatty acid esters, ethoxylated sorbitan fatty acid esters and glycerol or polyglycerol esters of fatty acids.

13. (canceled)

14. The solid cleansing composition as claimed in claim 1 wherein the emulsifier constitutes at least 4% wt and up to 14% wt of the solid cleansing composition.

15. The solid cleansing composition as claimed in claim 1 wherein the humectant is a humectant polyhydric alcohol or a humectant ester or humectant ether thereof.

16. The solid cleansing composition as claimed in claim 15 wherein the humectant is selected from compounds having from 2 to 6 hydroxyl groups and their di-, tri-, and oligomeric forms.

17. (canceled)

18. The solid cleansing composition as claimed in claim 1 wherein water constitutes at least 12% wt and up to 40% wt of the solid cleansing composition.

19. The solid cleansing composition as claimed in claim 1 which comprises: (a) at least 15% wt and up to 40% wt of a non-soap anionic surfactant having a melting point of at least 45° C.; (b) at least 10% wt and up to 32% wt of a carrier having a melting point of at least 45° C.; (c) at least 4% wt and up to 14% wt of an emulsifier; (d) at least 12% wt and up to 40% wt of a humectant; (e) at least 10% wt and up to 36% wt of water; wherein components (a) to (e) make up at least 70% and preferably at least 85% of the weight of the solid cleansing composition.

20.-22. (canceled)

23. The solid cleansing solid cleansing composition as claimed in claim 1 which has a completely or predominantly homogeneous microstructure.

24. (canceled)

25. An emulsion for the preparation of a solid cleansing composition, the emulsion comprising (a) at least 11% wt of a non-soap anionic surfactant having a melting point of at least 45° C.; (b) at least 7% wt of a carrier having a melting point of at least 45° C.; (c) at least 3% wt of an emulsifier; (d) at least 7 wt % of a humectant; and (e) at least 10% wt water; wherein the emulsion is flowable at a temperature of at least 45° C.

26. An emulsion for the preparation of a solid cleansing composition, the emulsion comprising (a) at least 14% wt and up to 36% wt of a non-soap anionic surfactant having a melting point of at least 45° C. (and preferably at least 16% wt and up to 28% wt of this component); (b) at least 10% wt and up to 32% wt of a carrier having a melting point of at least 45° C. (and preferably at least 12% wt and up to 24% wt of this component); (c) at least 4% wt and up to 14% wt of an emulsifier (and preferably at least 6% wt and up to 12% wt of this component); (d) at least 10 wt % and up to 36% wt of a humectant (and preferably at least 12% wt and up to 30% wt of this component); and (e) and at least 12% wt and up to 40% wt water (and preferably at least 14% wt and up to 32% wt of this component); wherein the emulsion is flowable at a temperature of at least 45° C., and wherein components (a) to (e) make up at least 70%, preferably at least 80%, more preferably at least 90% of the weight of the emulsion.

27. A method of making a solid cleansing product as claimed in claim 1, the method comprising: (i) providing the emulsion at a temperature at which it is flowable, and (ii) subjecting the emulsion to cooling and solidification to form the solid cleansing product; wherein the method takes place without water loss or with water loss not exceeding 50% of the mass of water added to form the emulsion; preferably not exceeding 40% of the mass of water added to form the emulsion; and preferably not exceeding 30% of the mass of water added to form the emulsion.

28. A method of providing individual personal cleansing bars by re-melting a larger solid cleansing product as claimed in claim 1, adding any colorants, perfumes that are required and casting the flowable composition into moulds.

Description

EXAMPLE 1

[0345] The following ingredients were employed in the amounts stated below.

TABLE-US-00001 Ingredient As added % wt Water 25.0 PUREACT I-78 31.5 Glycerol 17.5 Tetrasodium glutamate diacetate 0.2 Monopropyl glycol (MPG) 2.0 DUROSOFT PG4L-SG (emulsifier) 7.8 Hydrogenated sunflower oil 16.0

[0346] PUREACT 1-78 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.

[0347] DUROSOFT PG4L-SG (formerly known as 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 PG4L-SG has an HLB value of 8.8.

[0348] The emulsifier DUROSOFT and the glycerol were added to the water, which was at 90° C. The sodium cocoyl isethionate (SCI) was melted and blended to the composition. The hydrogenated sunflower oil was melted and was added last together with any further ingredients. The mass was worked for about 5 hours, whilst still liquid/molten. The resulting emulsion, a readily flowable liquid, was poured into a mould and allowed to cool under ambient conditions, producing a block of 11.5 kg weight.

[0349] The pH of the solid cleansing composition was 6-7 at 10% dilution, as measured by a commercial pH meter.

[0350] The moisture level of the cooled block was approximately 20 wt %; during the method some water was lost to the atmosphere. The solidified composition was as follows:

TABLE-US-00002 Ingredient of solid composition % wt Water 20.0 PUREACT I-78 33.6 Glycerol 18.7 Tetrasodium glutamate diacetate 0.2 Monopropyl glycol (MPG) 2.1 DUROSOFT PG4L-SG (emulsifier) 8.3 Hydrogenated sunflower oil 17.1

[0351] The resulting block could be heated (for example to temperatures in the range 65° C. to 85° C.), thereby re-melting it, additised with any desired additive, for example selected from colorants, opacifiers and perfumes, and cast into small individual cleansing bars or tablets for personal use. It is found that such bars or tablets form perfectly without any degradation of the cleansing composition, and do not crack, shrink or distort in any way. The emulsification and humectant system is highly effective is stabilising the composition in the solid and liquid phases.

[0352] The cleansing bars can be used for skin and hair cleansing.

EXAMPLE 2

[0353] The following ingredients were employed in the amounts stated below.

TABLE-US-00003 As added In solid composition Ingredient % wt % wt Water 25.0 20.0 PUREACT I-78 20.8 22.2 Glycerol 27.0 28.8 Tetrasodium glutamate diacetate 0.2 0.2 Monopropyl glycol (MPG) 1.0 1.1 DUROSOFT PG4L-SG (emulsifier) 8.0 8.5 Hydrogenated sunflower oil 18.0 19.2

[0354] The method was carried out as described in Example 1. The composition of the resulting solid composition is as shown above. It will be seen that there was a small water loss.

[0355] As with Example 1, the physical properties, stability, re-melt performance and cleansing performance of the cleansing composition were excellent.

EXAMPLE 3

[0356] The following ingredients were employed in the amounts stated. Addition of the ingredients was in the order stated, starting with water.

TABLE-US-00004 As added In solid composition Ingredient % wt % wt Water 24.5 19.5 PUREACT I-78 23.6 25.2 Glycerol 25.0 26.7 Tetrasodium glutamate diacetate 0.2 0.2 Monopropyl glycol (MPG) 1.0 1.1 DUROSOFT PG4L-SG (emulsifier) 7.0 7.5 Hydrogenated sunflower oil 18.7 19.9

[0357] The method was carried out as described in Example 1. The composition of the resulting solid composition is as shown above. It will be seen that there was a small water loss.

[0358] As with Example 1, the physical properties, stability, re-melt performance and cleansing performance of the cleansing composition were excellent.

EXAMPLE 4

[0359] The following ingredients were employed in the amounts stated. Addition of the ingredients was in the order stated, starting with water.

TABLE-US-00005 As added In solid composition Ingredient % wt % wt Water 25.0 20.0 PUREACT I-78 20.0 21.3 Glycerol 26.0 27.7 Tetrasodium glutamate diacetate 0.2 0.2 Monopropyl glycol (MPG) 1.0 1.1 DUROSOFT PG4L-SG (emulsifier) 8.8 9.4 Sodium benzoate 0.5 0.5 Potassium sorbate 0.5 0.5 Hydrogenated sunflower oil 18.0 19.2

[0360] The method was carried out as described in Example 1. The composition of the resulting solid composition is as shown above. It will be seen that there was a small water loss.

[0361] As with Example 1, the physical properties, stability, re-melt performance and cleansing performance of the cleansing composition were excellent.

EXAMPLE 5

[0362] Example composition 5 was prepared as described above for Example 1 with the following ingredients to produce a solid cleansing composition.

TABLE-US-00006 As added Ingredient % wt Water 24.90 PUREACT I-78 24.60 Glycerol 16.30 Tetrasodium iminodisuccinate 0.20 Monopropyl glycol (MPG) 1.00 DUROSOFT PG4L-SG (emulsifier) 3.00 Hydrogenated sunflower oil 17.00 DUROSOFT GML 7.00 Cetearyl Alcohol 1.50 Sunflower Wax 4.50

[0363] DUROSOFT GML is Glyceryl Mono Laurate, an emulsifier having an HLB of 5.2.

[0364] As with Example 1, the physical properties, stability, re-melt performance and cleansing performance of the cleansing composition were excellent. The hardness of the cleansing composition was observed to be greater than the hardness of the cleansing composition of Examples 1-4 and no cracking or surface oiling was observed.

EXAMPLE 6

[0365] Example composition 6 was prepared as described above for Example 1 with the following ingredients to produce a solid cleansing composition.

TABLE-US-00007 As added Ingredient % wt Water 22.20 PUREACT I-78 24.60 Glycerol 19.00 Tetrasodium iminodisuccinate 0.20 Monopropyl glycol (MPG) 1.00 DUROSOFT PG4L-SG (emulsifier) 3.00 Hydrogenated sunflower oil 17.00 DUROSOFT GMO 7.00 Cetearyl Alcohol 1.50 Sunflower Wax 4.50

[0366] DUROSOFT GMO is Glyceryl Mono Oleate, an emulsifier having an HLB of 4.2.

[0367] As with Example 1, the physical properties, stability, re-melt performance and cleansing performance of the cleansing composition were excellent. The hardness of the cleansing composition was observed to be greater than the hardness of the cleansing composition of Examples 1-4 and no cracking or surface oiling was observed.