US3457175A - Shampoos - Google Patents

Description

United States Patent 3,457,175 SHAMPOOS Kenneth Vasey Curry, Camberley, Surrey, England, as-

signor to Lever Brothers Company, New York, N.Y.,

a corporation of Maine No Drawing. Filed Dec. 21, 1965, Ser. No. 515,444 Claims priority, applicationzglgeat Britain, Jan. 4, 1965,

31 Int. Cl. A61k 7/08; (311d 1/14, 1/24 US. Cl. 252-89 4 Claims ABSTRACT OF THE DISCLOSURE The specification discloses shampoo formulations containing a solvent combination having high solvency power for the grease of the hair. The solvent combinations disclosed are (1) mixtures of dipropylene glycol and the monomethyl ether of diethylene glycol and (2) mixtures of glycerine and polyethylene glycol.

This invention relates to shampoos.

It has been found that certain solvents when used together in pairs in a shampoo have an unexpectedly high solvency power for the grease of the hair.

According to the invention there is provided a shampoo containing dipropylene glycol in combination with methyl digol (the monomethyl ether of diethylene glycol) or glycerine in combination with a polyethylene glycol.

The combined solvents may suitably constitute up to 5% by weight of the shampoo, preferably from 1 to 3%.

The dipropylene glycol or the glycerine, preferably constitutes from 20 to 80% by weight of the combined solvents.

The molecular weight of the polyethylene glycol is not critical, similar results having been obtained with diand triethylene glycol as with the high molecular weight glycols.

Conventional surface-active agents can be used in the shampoo, for example alkyl sulphates, alkyl benzene sulphonates, and alkyl ether sulphates.

The following are examples of typical shampoo formulae in accordance with the invention. Percentages are by weight.

3,457,175 Patented July 22, 1969 The unexpected solvency power for greases of the hair exhibited by the above pairs of solvents was demonstrated by the following experiment that was carried out.

A synthetic sebum Was first prepared; this had the fol lowing composition:

The synthetic sebum was dissolved in petroleum ether 40-60 C.) to give a 5% solution. 10 mls. of this solutlon were pipetted into each of three ml. beakers and the solvent evaporated off on a steam bath to give 0.50 g. of sebum in each beaker. The beakers were then allowed to cool in a desiccator and then weighed to check that all the petroleum ether and moisture had been removed.

20.00 g. of shampoo containing the solvents indicated in the table were then added to each beaker and then the beakers were placed on a water bath maintained at 40 C. for one hour with gentle agitation.

The solidified sebum broke up under the treatment and become suspended in the form of small solid particles in the warm shampoo.

These suspensions were then filtered to remove undissolved sebum and then cooled.

A ten gram sample of each shampoo was then weighed out and 100 mls. of 50% aqueous ethanol added and the solution warmed to assist solubilisation. The solution was again cooled and washed into a 250 ml. separating funnel with a further 50 mls. of 50% aqueous alcohol.

This solution was then extracted with 3X50 mls. of petroleum ether (40-60 C.) and the petroleum ether extracts combined and back washed with 2X20 mls. of distilled water.

The washed petroleum ether extract was then dried by filtering through a funnel containing anhydrous sodium sulphate into a tared flask and evaporating the petroleum ether on the steam bath. The residue in the flask was finally dried in an oven at 60 C. for one hour, cooled in a. desiccator, and then weighed. The sample was heated in the oven until a constant weight was obtained.

The above process was repeated using shampoo which had not been treated with sebum, to obtain the amount of petroleum ether soluble material already present in the shampoo, so that the true weight of sebum dissolved could be obtained.

The results are indicated in the following table. The shampoo base in each case was 16.5% monoethanolamine lauryl sulphate.

TABLE Percent Solvent in Shampoo Polyethylene Glycol (1500) Dipropylone Methyl Glycer- Glycol Digol P 95 95 9? 1- Nr-HNN no on cnqueaqlgo What is claimed is:

1. A shampoo preparation for cleaning hair and dissolving hair grease cOnsisting essentially of an organic anionic surface active agent, water, and from about 1% to about 5% by weight of a solvent for the grease of the hair selected from the class consisting of (1) a mixture of from about 20% to about 80% by weight dipropylene glycol and the balance the monomethyl ether of diethyl ene glycol and (2) a mixture of from about 20% to about 80% by weight glycerine and the balance polyethylene glycol.

2. The shampoo as defined by claim 1 wherein the amount of said solvent is from about 1% to about 3% by weight.

- 4 3. The shampoo as defined by claim 1 wherein the solvent is said mixture of dipropylene glycol and the monomethyl ether of diethylene glycol.

4. The shampoo as defined in claim 1 wherein the solvent is said mixture of glycerine and polyethylene glycol.

References Cited UNITED STATES PATENTS 2,978,416 4/1961 Fein et a1. 252161 3,085,067 4/1963 Anderson. 3,152,046 10/1964 Kapral l67-87 FOREIGN PATENTS 911,214 11/1962 Great Britain.

OTHER REFERENCES Specially Polyols, Lehne, Amer. Perf. and Cosmetics, v01. 78, No. 10, October 1963, pp. 103-107.

Polyethylene Glycols, Lesser Drug and Cosmetic Industry, September 1951; 69, 3, pp. 316, 317, 378, 379, 396- 401.

LEON D. ROSDOL, Primary Examiner P. E. WILLIS, Assistant Examiner US. Cl. X.R. 252-161