GB2343189A

GB2343189A - Skin cleansing composition

Info

Publication number: GB2343189A
Application number: GB9823440A
Authority: GB
Inventors: Adam Mather; Anthony Dymond
Original assignee: Tetrosyl Ltd
Current assignee: Tetrosyl Ltd
Priority date: 1998-10-27
Filing date: 1998-10-27
Publication date: 2000-05-03
Anticipated expiration: 2018-10-27
Also published as: GB2343189B; GB9823440D0

Abstract

A skin cleansing composition in the form of an emulsion comprises by weight of the total composition: <SL> <LI>(a) an oil phase incorporating: <LI>(i) 5% to 30% by weight of a liquid di-alkyl ester of a dibasic carboxylic acid or a mixture of such esters, and <LI>(ii) 1 to 10% by weight of a hydrocarbon solvent such as limonene; and <LI>(b) a water phase incorporating <LI>(i) 2 to 40% by weight of a water soluble emulsifying system stabilising the emulsion, and <LI>(ii) 15 to 70% by weight of water. </SL>

Description

SKIN CLEANSING COMPOSITION The present invention relates to a skin cleansing composition and more particularly, but not exclusively, to such a composition intended for removing hydrophobic materials such as oils, grease, paint and resin from skin. The invention relates even more particularly, but again not exclusively, to such a composition for use as a hand cleanser.

It is of course well known that hydrophobic materials are difficult to remove from skin by use of ordinary soap and water. Consequently a variety of hand cleansers for removing hydrophobic materials have been developed and are commercially available. Such hand cleansers are generally used by working the composition into the skin to"lift"the hydrophobic material from the skin followed by rising of the composition from the skin, e. g. with warm water. As such, the compositions are so formulated as to have both hydrophobic and hydrophilic characteristics. The former being for the purpose of removing soil and the latter to allow water removal.

Hand cleansers as described generally fall into one of two categories. One category comprises formulations which are effective particularly for the removal of oil and grease (and are therefore sold and recommended as such) but have rather less capability for removing paint and resin. Compositions in the other category are effective for removing paint and resin but rather less so for cleaning hands soiled with oil and grease.

It will therefore be appreciated that thorough cleansing of hands soiled with oil and/or grease and also with paint and/or resin has required the use of two different cleansing compositions. From the users point of view this is something of an inconvenience and involves the expense of purchasing two different cleansing compositions. From the manufacturers point of view, the need for two compositions means that they are not able to offer a single composition which is effective for removal of oil, grease, paint and resin.

According to the present invention there is provided a skin cleansing composition in the form of an emulsion comprising, by weight of the total composition: (a) an oil phase incorporating: (i) 5% to 30% by weight of a liquid di-alkyl ester of a dibasic carboxylic acid or a mixture of such esters, and (ii) 1 to 10% by weight of a hydrocarbon solvent; and (b) a water phase incorporating (i) 2 to 40% by weight of a water soluble emulsifying system stabilising the emulsion, and (ii) 15 to 70% by weight of water.

We have found, and this forms the basis of the present invention, that a formulation as defined above is effective for removing a wide range of hydrophobic materials from skin including (but not only) oils, grease, paint and resin.

Consequently the invention overcomes the disadvantages of the prior art as outlined above.

Preferred compositions of the invention are in the form of oil-in-water emulsions although depending on the amounts of the various components it is possible to produce water-in-oil emulsions.

The composition of the invention may be used in the same manner as the prior art composition, i. e. by working the composition into the skin to"lift"the hydrophobic soil and then effecting water rinsing.

Component (a) (i) is present in the composition in an amount of 5% to 30% by weight (based on the total weight of the composition) and is particularly effective for the removal of resin from skin. Preferably component (a) (i) provides 5% to 20%, more preferably 7% to 15%, and even more preferably 8% to 12% by weight of the total weight of the composition. It is particularly preferred that component (a) (i) provides about 10% by weight of the composition.

The ester or esters of component (a) (i) is/are preferably selected from di-(C, 3) alkyl esters of aliphatic dibasic C4~6 carboxylic acids. The methyl esters are preferred and as such preferred compounds for use as component (a) (i) include dimethyl succinate (DMS), dimethyl glutarate (DMG) and dimethyl adipate (DMA).

It is particularly preferred that component (a) (i) comprises a mixture of a major proportion of DMG together with lesser proportion of DMA and DMS. More preferably, component (a) (i) comprises (based on the weight of component (a) (i)) 12% to 23% DMA, 15% to 25% DMS and 55% to 65% DMG.

A suitable material for use as component (a) (i) is available under the name ESTASOL.

A further component of the oil phase of the composition of the invention is a hydrocarbon solvent. For use in the invention such a solvent should of course be skin compatible, i. e. no deleterious effect on skin within the time scale of use of the composition. The amount of the solvent present in the composition is 1% to 10%, more preferably 3% to 8% and even more preferably 4% to 6% by weight of the composition. A particularly suitable amount is about 5% by weight on the same basis.

One example of hydrocarbon solvent which may be used is kerosene.

It is however more preferred to use a terpene and most preferably D-limonene which is not only very effective for paint and resin removal but also imparts a pleasant aroma of oranges to the composition.

The composition contains 2% to 40% of water soluble emulsifying system (b) (i) which serves to stabilise the emulsion.

The water soluble emulsifying system preferably includes an emulsifying wax and optionally (but preferably) also a soap.

The emulsifying wax preferably provides 2% to 20% by weight of the total weight of the composition, more preferably 2% to 10%, even more preferably 3% to 8%, e. g. and most preferably 4% to 6% by weight on the same basis. A particularly suitable amount of emulsifying wax is about 5% on the basis as quoted.

The emulsifying wax, in addition to stabilising the emulsion gives structure to the composition and provides and"after feel"after a skin cleansing operation.

The emulsifying wax may for example comprise at least one and preferably both of an ester ethoxylate of a long chain (preferably Cl6 8) fatty acid (e. g. PEG 20 stearate) and a long chain (preferably ci6-i8) fatty alcohol (e. g. cetearyl alcohol).

A particularly suitable emulsifying wax for use as component is available under the name POLAWAX which is a water soluble material comprised of PEG 20 stearate and cetearyl alcohol.

The soap (if used) may be present in the composition in an amount of 2% to 20% by weight, more preferably 2% to 10%, even more preferably 3% to 8% and most preferably 4% to 6% by weight of the total weight of the composition. A particularly suitable amount is about 5.5% on the same basis.

The soap will comprise a salt of a long chain (preferably C, 6, 8) carboxylic acid. The soap may be an alkali metal soap but is more preferably mono-, di-or triethanolamine soap. It is preferred to employ tri-ethanolamine soap and a particularly suitable example is triethanolamine stearate.

The composition preferably also incorporates up to 2% (preferably about 1%) by weight of a polyoxyethylene sorbate (e. g. 85 EO) which assists emulsification of the dibasic ester (s).

In addition to the components detailed above it is also preferred to include in the composition beads (e. g. of a polymeric material such as HDPE) having a size of 200 to 500 um, preferably 300 to 350 um. Such beads, which may be present in an amount of 1% to 10%, e. g. 4% to 8% by weight of the composition, serve to assist in removal of cleansing the grain of the skin.

A further optional, but preferred, component of the composition is talc (magnesium silicate) which may be present in an amount up to 30%, more preferably 5% to 15%, and ideally about 10% by weight of the composition. Talc gives bulk to the composition and"after feel"properties.

A further preferred addition for the composition is a preservative. Colouring agents may also be included.

Compositions in accordance with the invention will generally be formulated to have a paste-like consistency for packaging in a tub thus allowing the user to scoop an amount of the composition out of the tub and use it for cleansing purposes.

Compositions in accordance with the invention may be produced by blending together at elevated temperature (e. g. 60 C-70 C) the ester or esters of component (a) (i) and the hydrocarbon solvent together with any emulsifying wax present in the emulsifying system (b) (i). Furthermore if system (b) (i) includes a soap then the fatty acid component of that soap may be co-blended with the hydrocarbon solvent, ester (s) and any emulsifying wax. To the heated blend may be added similarly heated water.

If the emulsifying system includes a soap for which the"parent"acid was included in the blend of hydrocarbon solvent and ester (s) then the water will also include a dissolved base which reacts with the acid to generate the soap. The water may also contain any preservative required for the composition. The resulting blend may then be cooled, e. g. to 30 -35 C to produce a stable emulsion. At this stage, beads and/or talc (if either or both used) may be blended into the composition to produce the final product.

The invention is illustrated by the following non-limiting Example.

Example The following components were used to produce a hand cleansing composition by the procedure described below.

Component Amount (by weight) ESTASOL 10% Talc 10% Polawax 5% Stearic acid 4% Triethanolamine 1 % D-Limonene 5% HDPE Beads (325m) 6% Preservative 0.1 % Water Balance The Polawax (an emulsifying wax), ESTASOL (a blend of DMA, DMG and DMS), D-Limonene, and stearic acid were blended together with heating to 65 C. To the resulting blend was added, with mixing, a heated (65 C) blend of the water, triethanalamine and preservative. On cooling to 30 -35 C, the mixture gave a stable oil-in-water in oil emulsion. Into this emulsion were blended the HDPE beads and the talc.

The final composition was suitable for use as a hand cleanser and effectively removed oil, grease, paint and resin from skin.

Claims

CLAIMS 1. A skin cleansing composition in the form of an emulsion comprising, by weight of the total composition: (a) an oil phase incorporating: (ii) 5% to 30% by weight of a liquid di-alkyl ester of a dibasic carboxylic acid or a mixture of such esters, and (ii) 1 to 10% by weight of a hydrocarbon solvent; and (b) a water phase incorporating (i) 2 to 40% by weight of a water soluble emulsifying system stabilising the emulsion, and (ii) 15 to 70% by weight of water.
2. A composition as claimed in claim 1 wherein component (a) (i) is present in the composition in an amount of 5% to 20% by weight.
3. A composition as claimed in claim 2 wherein component (a) (i) is present in the composition in an amount of 7% to 15% by weight.
4. A composition as claimed in claim 3 wherein component (a) (i) is present in the composition in an amount of 8% to 12% by weight.
5. A composition as claimed in claim 4 wherein component (a) (i) provides about 10% by weight of the composition.
6. A composition as claimed in any one of claims 1 to 6 wherein component (a) (i) comprises at least one di- (CI-3) alkyl ester of an aliphatic dibasic C4-6carbolxylic acid.
7. A composition as claimed in claim 7 wherein component (a) (i) comprises dimethyl succinate, dimethyl glutarate and dimethyl adipate.
8. A composition as claimed in claim 7 wherein component (a) (i) comprises based on the weight of component (a) (i) 12% to 23% by weight dimethyl adipate, 15% to 25% by weight dimethyl succinate and 55% to 65% by weight dimethyl glutarate.
9. A composition as claimed in any one of claims 1 to 8 wherein the hydrocarbon solvent (a) (ii) is present in an amount of 3% to 8% by weight of the composition.
10. A composition as claimed in claim 9 wherein the hydrocarbon solvent (a) (ii) is present in an amount of 4% to 6%.
11. A composition as claimed in claim 10 wherein the hydrocarbon solvent is present in amount of about 5% by weight of the composition.
12. A composition as claimed in any one of claims 1 to 11 wherein the hydrocarbon solvent is a terpene.
13. A composition as claimed in claim 12 wherein the terpene is D-Limonene.
14. A composition as claimed in any one of claims 1 to 13 wherein the water soluble emulsifying system (b) (i) includes an emulsifying wax.
15. A composition as claimed in claim 14 wherein the emulsifying wax provides 2% to 20% by weight of the total weight of the composition.
16. A composition as claimed in claim 15 wherein the emulsifying wax provides 2% to 10% by weight of the total weight of the composition.
17. A composition as claimed in claim 16 wherein the emulsifying wax provides 3% to 8% by weight of the total weight of the composition.
18. A composition as claimed in claim 17 wherein the emulsifying wax provides 4% to 6% by weight of the total weight of the composition.
19. A composition as claimed in claim 18 wherein the amount of the emulsifying wax is about 5% by weight of the composition.
20. A composition as claimed in any one of claims 15 to 19 wherein the emulsifying wax comprises a polyethylene glycol ester of a long chain fatty acid.
21. A composition as claimed in claim 20 wherein said polyethylene glycol ester is PEG 20 stearate.
22. A composition as claimed in any one of claims 1 to 21 wherein the water soluble emulsifying system (b) (i) includes a soap (b) (ii).
23. A composition as claimed in 1 wherein the soap is present in the composition in an amount of 2% to 20% by weight.
24. A composition as claimed in 23 wherein the soap is present in the composition in an amount of 2% to 10% by weight.
25. A composition as claimed in 24 wherein the soap is present in the composition in an amount of 3% to 8% by weight.
26. A composition as claimed in 25 wherein the soap is present in the composition in an amount of 4% to 6% by weight.
27. A composition as claimed in 26 wherein the soap is present in the composition in an amount of about 5.5% by weight.
28. A composition as claimed in any one of claims 22 to 27 (b) (ii) is triethanolamine soap.
29. A composition as claimed in claim 28 wherein the soap is tri-ethanolamine stearate.
30. A composition as claimed in any one of claims 1 to 29 incorporating beads having a size of 200 to 500pm.
31. A composition as claimed in claim 30 wherein said beads are of HDPE.
32. A composition as claimed in claim 30 or claim 31 wherein said beads are present in the composition in an amount of 1% to 10% by weight.
33. A composition as claimed in any one of claims 1 to 32 incorporating talc.
34. A skin cleansing composition in the form of an emulsion comprising, by weight of the total composition: (a) an oil phase incorporating: (i) 10% by weight of a dimethyl ester of a dibasic C4-6carboxylic acid or a mixture of such esters, and (ii) about 5% by weight D-Limonene; (b) (i) about 5% by weight of an admixture of PEG 20 stearate and cetearyl alcohol, and about 5.5% by weight of triethenolamine stearate; (c) (b (ii) 15 to 70% by weight of water emulsified in said continuous phase; and (c) about 6% by weight polymeric beads.
35. A composition as claimed in any one of claims 1 to 34 in the form of an oil-in water emulsion.