US2087953A - Process and composition for rectification of curly hair - Google Patents

Description

Patented July 27, 1937 UNITED STATES PROCESS AND COMPOSITION FOR RECTIFI- OATION OF CURLY HAIR Julian Y. Malone, Joseph H. Carroll, and Charles R. McKee, Milwaukee, Wis., assignors to The Perwav Company, Milwaukee, Wis, a

tion of Wisconsin No Drawing.

3 Claims. This. invention deals with compositions and methods for removing objectionably obdurate kinkiness or curliness from human hair.

duce it to an easily moidable state. The mineral binder, present in proportion sufficient to render the composition pastelike, serves to preserve the hair in straightened order produced by brushing or combing until the softening ingredients of the composition effectively de-elasticizes the hair so that the kinkiness or curliness thereof is more or less completely removed and a practically straightened condition produced which, after removal of the composition, is preserved. Sometimes it is also desirable to include in the composition emollients such as glycerine, or tri,- ethanolamine, or other substituted amines, which will tend to adhere to the hair after the remainder of the composition is removed and prevent the hair from becoming dry.

The composition of this invention is an improvement upon compositions heretofore employed for the purpose. Compositions known prior to this invention have been harsh and irritating and, in some cases, dangerously so. Previously known compositions of any merit which have actually produced what might be called a permanent straightening of hair have depended for their action upon very strong free alkalies. These alkalies, together with waxes and the like, when applied to the hair have exerted a softening action. The amount of free alkali necessary to obtain this efiect has invariably exceeded a non-irritating concentration and the tendency has been to reduce the concentration of alkali in order to avoid irritation, in which case the softening action necessary to obtain permanent straightening has been lost. In the composition of this invention, on the other hand, the principal softening agents are negative radicals and free alkali is neither necessary nor desirable, although nonirritating amounts thereof may be employed. The mineral binder employed with this invention provides the necessary temporary retention of the hair, but at the same time, due to the ease of wetting thereof by the softening solution, the latter has at all times free and complete access to all parts of the hair surface.

In preparing the composition of this invention corpora- Application February 19, 1934, Serial No. 711,988

a soiution of stannous chloride is prepared to which solution suflicient alkali hydroxide, such as sodium hydroxide, is added to convert all of the stannous chloride to sodium stannite. To this is then added sodium polysulfide solution prepared by digesting sulphur in alkali hydroxide solution. To this alkali stannite, alkali sulfide composition is then added a small amount of zinc sulfate, suflicient to combine with all free alkali present forming alkali zincate, which substance, although of minor softening properties, itself substantially enhances the softening properties of the stannite and polysulfide. Inasmuch as the softening property of tin is dependent upon the tin being present in a stannous condition, there is added to the composition suflicient protective reducing agent, such as sodium hyposuliite to prevent atmospheric oxidation of the tin. This solution containing the softening and protective agents is then employed for the purpose of compounding a paste or cream in which the solution is the suspending fluid. The preferred manner of preparing such paste is to add alkali earth oxides directly to the solution. The alkali earth oxide added to the solution becomes hydrated therein and after the elapse of sufli'pient time an extremely fine, smooth, colloidal, mineral binder is formed. Theresult is a paste or cream which is smooth and plastic to a high degree. It is preferred that the proper amount of alkali earth oxide be added to produce a cream just stiff enough to stand alone. This may be varied widely, of course, depending upon the preference of the operator, but it should be borne in mind that the paste should have sufficient mobility so that it can be worked well into a head of hair and at the same time suflicient stiffness to maintain the hair in straightened condition.

In employing the composition described above, the paste is worked thoroughly into the hair and the hair is then combed until it lies in straightenedorder. The composition is then permitted to dry or'partially dry upon the hair. This occurs within an interval of about fifteen minutes to half an hour and may be hastened somewhat by the use of a hot air dryer. During this interval of drying, the hair is held in straightened order by the mineral binder and while so held the softening solution acts upon the hair substance itself. Large amounts of fluid are taken up by the hair, causing it to swell. Under the action of the softening agent the cement substance between hair cells is softened and this allows the cells to shift their relative position so that when the hair again hardens the new position is assumed. The elasticity of the hair returns as shown by its assuming the straight position after being bent, just as the hair prior to any treatment assumes the kinky position after being held straight. At the completion of the drying interval the dried material is preferably rinsed out with clear water. The hair is then combed to proper configuration and dried. The hair so straightened can also be shampooed with soap to remove the composition, if desired, without danger of recurrence of the kinky state, but the rinsing with clear water is more effective. After the hair has been so treated the new configuration of the hair will remain without reversion until replaced by new growth.

A useful addition to the paste as prepared above is a small amount of water-soluble emollient, such as glycerine or triethanolamine, or other substituted amines. When an emollient is employed the hair may be dressed and handled with greater facility after treatment; there is less tendency on the part of the hair to become excessively dry; and the straightening effect is somewhat improved. The emollient is also beneficial in its effect upon the paste, imparting a certain lubricity thereto which makes the paste easier to comb into the hair. The following directions for compounding may sometimes be employed:

Eight parts by weight of sodium hydroxide are dissolved in twelve parts by weight of water. To this is added six parts by weight of sodium polysulfide solution, formed by digesting sulphur in a forty percent solution of sodium hydroxide. To this is then added two parts by weight of stannous chloride contained in twenty-five parts by weight of water. There is then added two parts by weight of zinc sulphate dissolved in twentyfive parts by weight of water, and finally four parts by weight of sodium hyposulfite dissolved in sixteen parts by weight of water is added. A small amount of undissolved solids may remain and the solution as above prepared may be filtered to remove the solids. To about two parts by weight of the above solution is then added approximately one part by weight of MgO. After the elapse of a period of time this mixture sets into a thick paste. This thick paste is then thoroughly stirred while adding to about eighty-five parts by weight thereof approximately five parts of triethanolamine and four parts of glycerine. The paste is now in completed condition, but if through slight departures from the exact proportions or for other reasons the composition is not of exactly the desired consistency, this may be adjusted to either thicken it or thin it, as necessary, by the addition, respectively, of small amounts of MgO or small amounts of additional solution as first prepared.

In compounding the above composition the quantity of stannous chloride may be varied between relatively wide limits without producing an entirely inoperative composition. Some degree of operativeness will be found in the range between one-half to ten parts by weight of stannous chloride. In the case of zinc sulphate, this is also true in approximately the same range. The quantity of sodium hydroxide employed is related to the quantity of zinc and tin present. This can range between two to fifteen parts by weight.. The quantity of hyposulfite may range between three parts by weight and thirty parts by weight. The quantity of polysulfide solution employed may also be varied widely from two parts to twenty parts by weight. The quantity of magnesium oxide employed is entirely dependent upon the consistency of cream desired. This will be found to lie within the approximate neighborhood of three-fourths to two parts by weight of magnesium oxide to two parts by weight of solution, but variation therefrom may be resorted to if a different consistency is desired. The quantity or presence of the emollient is optional, the quantity shown being representative of only one functioning proportion within a wide range. Any quantity of triethanolamine from one-half to fifteen per cent is useful and the quantity of glycerine can vary within one-half to ten per cent.

Due to the chemical reactions which take place in compounding the composition under the above directions, a composition is formed which Will contain from three-tenths to eight per cent of stannous tin compounds, three-tenths to eight per cent of sodium zincate, two to fifteen per cent of sodium hypo-sulfite, and one-half to eighteen per cent of sodium polysulfide in addition to twenty-five to fifty per cent of magnesium hydrate and two to fifteen per cent of triethanolamine and one-half to ten per cent of glycerine, together with some neutral salts, such as sodium chloride and sulfate, and possibly some free alkali.

In the above composition the recognized equivalents of sodium, such as potassium, may be substituted. The sodium hypo-sulfite can be replaced with any other nonpoisonous, non-irritating, mild, reducing agent of sufiicient reducing activity to preferentially accept oxidation in the presence of stannous tin. Such reducing agents will hereinafter be referred to as protective agents. Examples of these are hydroquinone and Na2S.

The hydrated alkaline earth oxide which forms the mineral binder in the composition may be replaced in whole or in part by any well-known equivalent, such as calcium hydrate, and also, at times, as well by complex silicates with or without alumina such as kaolin, bentonite, or other colloidal mineral. Herein the term mineral binder will be employed to mean any of the above substances in a highly divided, suspended state.

What we claim as our invention is:

1. A composition of matter for the straightening of hair comprising three-tenths to eight per cent of basic compounds of stannous tin, threetenths to eight per cent of sodium zincate, two to fifteen per cent of sodium hyposulfite, one-half to eighteen per cent of sodium polysulfide, and twenty-five to fifty per cent of mineral binder.

2. A composition of matter for the straightening of hair comprising a suspension consisting of solid suspended matter and liquid, said liquid containing in the presence of hydroxyl ions and magnesium ions a non-depilating concentration of tin in stannous form as stannite and as stannous hydroxide, alkali polysulfide and alkali zincate, and the suspended matter consists of highly divided mineral binder.

3. The method of straightening obdurately curly hair which consists in applying to the hair a paste consisting in a mineral binder suspended in a softening solution containing from .3 to 8% of basic compound of stannous tin, to 18% of sodium polysulfide, and free hydroxyl mechanically extending the hair for retention in the extended state by the binder while permitting softening solution to remove the elastic tendency of the hair which would return the hair to curly condition, allowing the hair and applied composition to dry, and then removing the dried composition from the hair.

JULIAN Y. MALONE. JOSEPH H. CARROLL. CHARLES R. McKEE.