Drug – bio-affecting and body treating compositions – Live hair or scalp treating compositions – Shaving preparation
Reexamination Certificate
1999-09-01
2001-05-15
Spear, James M. (Department: 1615)
Drug, bio-affecting and body treating compositions
Live hair or scalp treating compositions
Shaving preparation
C424S070200, C424S070400, C424S070500
Reexamination Certificate
active
06231846
ABSTRACT:
FIELD OF INVENTION
This invention concerns hair treatment compositions such as depilatory products and hair straightening and permanent waving products.
BACKGROUND TO THE INVENTION
Hair treatment compositions such as depilatory products and hair straightening and permanent waving products typically contain reducing sulphur species such as sulphides and thioglycolates, with depilatory products commonly including calcium thioglycolate and hair straightening and permanent waving products commonly including ammonium thioglycolate. The reducing sulphur species generate a variety of sulphur-containing volatiles, including hydrogen sulphide, methanethiol, dimethyl sulphide and dimethyl trisulphide, which are present at low levels in air above such products. This results in an unpleasant odour, which increases substantially during use, which can be offensive to users.
The present inventors have surprisingly found that incorporating zinc compounds, particularly zinc oxide, in such hair treatment compositions substantially reduces malodour production, both on storage and in use.
SUMMARY OF THE INVENTION
Accordingly, the present invention provides a hair treatment composition containing reducing sulphur species, wherein the composition also includes a zinc compound.
The invention is applicable to a range of hair treatment compositions containing reducing sulphur species, particularly thiol compounds such as thioglycolates. For example, the invention is applicable to depilatory compositions (eg in milk, cream, lotion or gel form) including thioglycolate, particularly calcium thioglycolate, which typically have a pH of about 12.5. The invention is also applicable to hair straightening and permanent waving compositions (eg in lotion form) including thioglycolate, particularly ammonium thioglycolate, which typically have a pH in the range 7 to 9.5.
The zinc compound may be a zinc salt such as zinc carboxylate eg zinc acetate, zinc chloride etc. Preferably, however, the zinc compound is zinc oxide. A mixture of zinc compounds may be used, but it is preferred to use zinc oxide alone.
We have found that during depilation using thioglycolate-based depilatories, substantial quantities of one sulphur-containing volatile are evolved. Gas chromatographic (gc) and mass spectral (ms) analyses have identified this material as methanethiol. Other substances are likely also to contribute towards the perceived malodour in-use, but nevertheless methanethiol lies at the heart of the problem.
We have similarly found that methanethiol is also liberated during hair relaxation using thioglycolate-based perming products, although in this case there is additionally a substantial amount of hydrogen sulphide present (possibly as a result of the much lower pH compared with depilatories, typically 7 to 9.5 versus 12.5 in depilatories). As with depilatories other materials may play a part in the in-use malodour.
Gc analysis of headspace gas above thioglycolate-based hair treatment products, with and without zinc compounds, has shown that the presence of zinc compounds, particularly zinc oxide, substantially reduces the production of methanethiol. Subjective odour evaluation tests showed a corresponding reduction in malodour with products including zinc compounds, both on storage and in use.
The zinc compound, preferably zinc oxide, is suitably present in an amount in the range 0.05 to 15%, preferably 0.1 to 10%, more preferably 0.2 to 5%, most preferably 0.3 to 3%, typically about 0.5%, of the total weight of the composition.
The composition may include one or more fragrance ingredients, as is conventional in hair treatment compositions. It is surprisingly found that use of one or more acetal fragrance ingredients is particularly effective in reducing malodour production. Typical examples of acetal fragrance ingredients are:
1-(ethoxymethoxy)cyclododecane
4,4a,5,9b-tetrahydroindeno[1,2-&agr;][1 ,3]dioxine
5-(sec-butyl)-2-(2,4dimethyl-3-cyclohexenyl)-5-methyl-1,3-dioxane
2-(1-ethylpentyl)-1,3-dioxolane
1-(2,2dimethoxyethyl)benzene
2-Isobutyl-5-methyl-1,3-dioxane
2-(1-phenylethyl)-4-methyl-1,3-dioxolan
1-(2,2-dimethoxy-1-methylethyl)benzene
A perfume formulation for use with such hair treatment compositions will typically contain a number of different fragrance ingredients. In accordance with the invention it is preferred to use a perfume formulation containing at least 5% by weight of acetal fragrance ingredient or ingredients, eg one or more of those listed above.
An example of a preferred perfume formulation, containing a mixture of ingredients in hedonic accord with one another and which are reasonably stable in thioglycolate base, is as follows:
% w/w
Boisambrene Forte (Henkel) (acetal)
5.0
Florosa (Quest)
5.0
Indolal 10% in DPG (Dragoco) (acetal)
0.5
Jasmacyclene (Quest)
1.5
Jasmopyrane Forte (Quest)
3.0
Lily Aldehyde (Bush Boake Allen)
10.0
Methyl dihydrojasmonate (Quest)
20.0
Phenyl ethyl alcohol
15.0
The perfume formulation is suitably present in an amount in the range 0.1 to 2%, preferably 0.2 to 1%, of the total weight of the composition.
In a preferred aspect the invention thus provides a hair treatment composition comprising thioglycolate, zinc oxide and at least one acetal fragrance ingredient.
The composition generally also includes other ingredients appropriate to the type of hair treatment, as is known to those skilled in the art.
The invention also includes within its scope a method of reducing malodour of hair treatment compositions containing reducing sulphur species, comprising adding a zinc compound, preferably zinc oxide.
The invention will be further described, by way of illustration, in the following Examples and with reference to the accompanying figures in which:
REFERENCES:
patent: 5051252 (1991-09-01), Schultz et al.
patent: 218 931 (1987-04-01), None
patent: 622 109 (1994-11-01), None
patent: 674195 (1952-06-01), None
patent: 91/02538 (1991-03-01), None
Chemical Abstract, vol. 122, No. 18, May 1, 1995, Columbus, Ohio, US; abstract No. 221603 K. ARAI: “Deodorants containing metal oxides for efficient removal of various malodor” XP002036850 see abstract & JP 07 016 422 A (Kobe Steel Ltd.) Jan. 20, 1995.
Goulding Philip William
Perring Keith Douglas
Pillsbury & Winthrop LLP
Quest International B.V.
Spear James M.
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