US2899965A - Bromate-urea oxidative fixing - Google Patents

Description

I lt& States BROMATE-UREA OXIDATIVE FIXING Y COR [POSITION AND PROCESS No Drawing. Application July 9, 1954 Serial No. 442,440

Claims (Cl. 132-7) This invention relates generally to the treatment of a keratin containing material, such as hair, which has been partially reduced, and more particularly to treatment which will restore such a keratin containing material to its normal condition after. it has been so reduced by a'mercaptan or other reducing solution such as can be used in the permanent waving of hair.

Objects and advantages of the invention will be set forth in part hereinafter and in part will be obvious herefrom, or may be learned by practice with the invention, the same being realized and attained by means of the steps, compositions, combinations and improvements pointed out in the appended claims.

The invention consists in the novel steps, compositions, combinations and improvements herein described.

In the permanent waving of hair, particularly the cold Waving process, the hair-is treated with a mercaptan solution which reduces part of the keratin of the hair.

Subsequently the hair must be restored to a normal state and the excess mercaptan solution plus by-products of its reaction with the hair must be removed from the hair or rendered inactive. Thus it has been the practice to follow such mercaptan treatment of hair with a treatment whereby the hair is subjected to contact with a solution containing an oxidizing agent. This treatment is generally but not necessarily preceded by liberal water washing. -This treatment with the oxidizing agent, by oxidizing these reduced materials and so making them inactive as reducing agents, sets or fixes the hair so that it does not tend to relax or lose its configuration or Wave.

For a compound to be a suitable commercial fixing or neutralizing agent it must have unique and critical properties. In low concentrations and in a relatively, fast period of time the compound:

1) Must oxidize the long chain mercaptans present in the reduced keratin to disulfide linkages in order to return the hair towits-nonnal state. This type of oxidation is selective and critical for there are manyv compounds acting as oxidizing agents which will oxidize .mercaptans to groups other than disulfides, such as sulfoxy and sulfone groups. In the latter case, the hair is not converted back to its normal state. resulting in serious hair damage. Thus, the oxidation of the mercaptans in the keratin must be of a particular type if damage is to be avoided and a proper fixing action is to be elfectuated. (2') Must oxidize the short chain mercaptans present in the excess portion of the waving solution.

(3) Must not oxidize the chemical groups in the keratin, other than the mercaptan groups, for to do. so would result in undesirable side efiects such as bleaching of the hair, loss of resiliency, loss of strength, loss of elasticity and other. types of damage. A compound may be unsuitable as a fixing agent, therefore,.even though it possesses .the required oxidizing action on the long chain mercaptan of the keratin and short chain mercaptans of the waving solution. if it also oxidizes the other chemical groups of the keratin.

The materials heretofore used aswneutralizing agents 2,899,965 Patented Aug. 18, i959 are ammonium persulfate, hypochlorites, potassium bromate, sodium perborate and hydro-gen peroxide.

Ammonium persulfate, potassium bromate and sodium perborate, in addition to .showing very slow reaction, must also be used in substantial amounts. The hypochlorites, though more satisfactory on these points, have the disadvantages of objectionable odor and of exhibiting bleaching and other deleterious effects on the hair. Hydrogen peroxide, which under conditions of use reacts with moderately rapid speed and shows less tendency to bleach and impair hair fibre, has come to be preferred in commercial practice.

Hydrogen peroxide, however, has not, been ideal for this purpose since it .mustbe used under' acid conditions to prevent excessivebleaching of hair, and even when used according to such standard accepted methods-of use, noticeable bleaching'frequently occurs and oxidation of the mercaptans present is not always sufficiently com: plete during the time allowed'and in the concentrations practical for use to completely fix the wave in a permanent set.

It is an object ,of the present invention to provide an oxidizing agent which overcomes all the above mentioned disadvantages. Another object is to provide an agent that, in addition to; o'vercoming these disadvantages, fixes the wave more permanently than any previously used oxidizing a gent. A further object is to provide an OXidlZe ing agent which will produce an actual improvement in the condition of the hair. Still another objectis'to pro.- vide a neutralizer which will not cause organic materials with which it comes into contact to explode and burn. Another object of our invention is to provide a neutralizer which issafe for the skin of the patron as well as for that of the operator applying it. A further object of this invention is to provide a neutralizer which may be packaged as a solution, an emulsion or a powder, each remaining stable in such forms.- It is also an object of this invention to provide a method of neutralization which is fast, safe and completely effective.

We have found that if a chlorite, and preferably sodium chlorite, is used as the oxidizing agent, the reaction'with mercaptan is more rapidand is sufficiently complete, with concentrations'practical for use, tofix the wave more permanently thananyof the abovementionedoxidizing agents. The chlorite treatment has the added advantage of not bleaching the hair or otherwise impairing it.

The effectiveness of the chlorite treatment is influenced by the concentration and amount of chlorite solution used, the pH of the solution, the temperature of the solution, the time of treatment, andalso, by the concent-ration of and total amount of mercaptan to be treated, and the amount of hair to be treated.

An aqueous solution of chlorite may be completely effective. Addition of Na CO NaCl, Na SO Na HPO4, H PO H BO NaH PO H 50 and similar agents can be used to regulate'the rate of reaction and to assist in production of desirable final hair condition.

For an averagehead of hair, where the concentration of the mercaptan or other reducing agent varies from 0 through 25% and the quantity is any amount up to 6 ounces, solutions of chlorite ranging in concentration from /2% through 3%, and in amounts from 175 cc. to 2 liters, give optimum results. The pH of the chlorite solution may range from pH -7 to pH 12, preferably 9.5 to 10.5, and treatment time from 3 to 15 minutes at temperatures from 20 C. to C.

By applying a chlorite solution under the above conditions an effective and safe neutralizer for home permanent waving is obtained. In the home permanent waving today it must be realized that the user is-not a profes sionally skilled operator. Moreover, the human hair varies widely in construction and it is most important that a neutralizer be available that not only effectively sets the hair after reduction by a waving solution, but also that 1t gives a wide margin of safety when used by the unskilled or non-professional operator. The chlorite solution provides such an effective and safe neutralizer heretofore not obtained by the prior known neutralizers.

As an example of use, the hair, either dry or moistened with mercaptan or other reducing solution as 2 to 4 ounces of 4 to 8% alkaline mercaptan, such as ammonium thioglycolate or 20% bisulfite is wrapped on solid rods suitably fastened, then saturated or resaturated with the solution. The hair either covered, or exposed to room condi tions, is then allowed to remain in this saturated state at room temperature until sufficient time has elapsed for definite wave ridges to be visible when a strand of the hair is uncoiled. At this time the hair is freely flooded with water delivered from a standard spray at 40 to 50 C. Water flooding is continued until treatment of 3 to 5 minutes, or approximately 12 gallons of water is completed. Following this, 500 cos. of a suitable chlorite solution at 40 C. to 50 C. is poured over the hair, caught in a suitable container, and reapplied with cotton or other applicator continuously for 3 to 5 minutes. The chlorite solution is then discarded and the hair is unwound from the rods. When all curler rods have been removed, a second 500 ccs. portion of the chlorite solution is poured through the hair hair for 2 to 3 minutes.

For such use, our preferred formulations of chlorite solutions are:

Still another modification of this treatment consists of rinsing the hair with water as above or omitting the water rinse if desired and subsequently applying 175 cc. to 250 cc. of a suitable chlorite solution to the coiled hair, saturating the hair thoroughly with the chlorite solution and allowing the hair to remain undisturbed for 15 minutes. Following this the hair is uncoiled and any unused portion of the chlorite solution is applied to the ends of the hair.

Another method of use consists in treating hair as in method above outlined, but with use of 2 /2 to 4 ounces of 8 to 25% concentration of a suitable reducing solution. Also, instead of winding the hair around a curler rod, it may, if desired, be coiled into so called pin curls and suitably fastened.

For such methods, we prefer to use double the amount of chlorite solution, i.e., 360 cc. to 2 liters for entire treatment, or to increase the concentration of chlorite, or to treat the hair for double the length of time noted above.

An additional method of use consists in winding the hair, dry or moistened with Water, around hollow curler rods and suitably fastening each. Next, 4 to 6 ounces of 3 /2 to 7% alkaline mercaptan solution, or suitable concentration of other reducing agent at 35 to 50 C., is forced through the curls from inside of curl to outside by means of suitable pump or applicator. This treatment is continued until definite wave ridges are produced which are visible if hair is uncoiled. Then a continuous flow of water, 8 to 12 gallons, is run through the curlers, This is followed by pump or applicator treatment with suitable chlorite solution at 40 to 50 C., for 3 to 5 minutes. For such use, we prefer 180 cc. to 250 cc. of 1% to 3% chlorite solution.

Still another method of use consists in winding hair, which is dry, wet with water, or wet with the reducing solution, around a suitable curler rod, fastening hair in place and withdrawing the curler rod. The balance of 4 to 6 ounces of 4 to 20% reducing solution is then applied by means of a pump or any suitable applicator at room temperature for time required to produce definite wave ridges. Following this, liberal water rinse, as above, is given to the hair. Next the hair is treated for 3 to 5 minutes with 500 cos. of 1% chlorite solution at 40 to 50 C., then is uncoiled and treated with an additional 500 ccs. of 1% chlorite solution for 2 to 3 minutes.

Saturation of the water rinsed hair with to 250 cos. of suitable chlorite solution over a period of 15 minutes may be used instead of the above procedure.

Still another method of treatment consists in wetting the hair before or after it is wound about a suitable curler with a solution which contains a mixture of mercaptan, sulfites, bisulfites, or other reducing effects, sulfates or carbonates or combinations of any of these or, if desired, any of these alone. Heating devices, either exothermic chemical pads or machine heaters, are then placed about the curls and the hair plus solution is heated for 2 to 25 minutes as required for proper development of wave ridges with the solution being used and the hair being treated. The hair is then cooled and liberally rinsed with water. Each curl is then moistened with chlorite solution and allowed to stand Wet with the chlorite solution for several minutes. Then the curlers are removed and the balance of 500 cos. of chlorite solution poured through the hair and reapplied for 3 to 5 minutes.

Chlorite solutions are far more advantageous to use than any of the previous neutralizers. They have, hoW- ever, certain undesirable features which detract from their general commercial use. Because of their strong oxidizing properties chlorites tend to explode into flame and/ or cause certain organic materials when they come into contact to explode. In addition, chlorites have been found to decompose into products which irritate the human skin. These disadvantages are also possessed by other strong oxidizing neutralizing agents, such as the bromates; and the now described aspect of the invention, in regard to overcoming these disadvantages, apply to those neutralizing agents as well as chlorites.

, The process of neutralization requires intimate contact between the solutions and the scalp, between the solutions and organic materials utilized in the Wrapping of hair tresses (end papers) and in protecting the non-treated portions of the patrons head (cotton wadding and toweling). This contract presents a serious problem in view of the irritation and combustion properties of certain of the oxi- .dants.

Much effort has been expended to eliminate or obviate these aforementioned dangers. Furthermore, of lesser consequence, but nevertheless an important commercial consideration, is the problem of the stability of the solutions and emulsions.

The present processes of neutralization of the reduced hair involve a number of water rinses and neutralizer rinses, each of which is generally for a certain prescribed period of time. These treatments are time consuming and cumbersome, especially for the home user. Many neutralizers also require that the solutions be at elevated or reduced temperatures.

Prior attempts to avoid the above disadvantages have proved unsuccessful. One approach was to lessen the percentage of oxidant in the solution. This approach failed as the oxidant must be present in suflicient quantities to insure the complete oxidation of the reduced hair. Utilizing additional reagents created new problems, i.e., discoloration of the solution, malodor, lessening of the oxidizing property of the solution or partial or complete destruction of the neutralizing solution or emulsion.

We have found that the problem of skin irritation may be obviated and the explosive tendencies of the solutions of strong neutralizing agents may be eliminated by the addition to the neutralizer of a compound selected from the group consisting of urea and sodium lactate. It is believed that the reasons Why these compounds are so eifective in overcoming the vundesirableeffectsnormally produced by strong oxidizing agents such aschlorite. and bromates, are because. of the following properties possessed by each of said compounds:

(1) They prevent the neutralizingamaterialfrom drying down.

(2) When heated they give off carbon dioxide, .which takes up a large quantity of heat.

(3) They are acidic absorbers.

Although both the sodium lactate and the urea are equally eflicient in the prevention of combustion and skin irritation, the urea is preferred as itprovidesthe additional advantage of stabilizing the solutions and emul- In formulating our novel neutralizer we have found that the fire retardation effect of the urea is dependent upon the ratio between the amount of urea and the amount of oxidant in the solution. The complete prevention of explosiveburning occurs when the ratio, on a mole to mole basis, is 1.5 parts of urea to each part of oxidant. A decrease in the proportion renders the solution more susceptible to explode into flame; an increase in the ratio has no further effect on the retardation.

We have found that there is a similar trend in theuse of the sodium lactate. The lactate will function effectively as a fire retandant if the mole to mole ratio is about 2 parts of lactate to each part of oxidant.

In general, theamount of oxidant is-determined by the concentration of the reducing agent present in the waving lotion. It is therefore a simplematter to calculate the requisite addition of the urea or the sodium lactate. For example, for .05 mole of thioglycolic acid as the reducing agent one may employ 0.066 mole of sodium bromate as the neutralizing agentwith 0.122 mole of sodium lactate .as the additive. In like. manner, for .05 mole of thioglyco'lic acid, 0.1 mole of sodium chlorite is used with 0.2 mole of urea. Prior to the addition of the sodium lactate or urea to the bromate and chlorite neutralizer it wasimperative that they be transported as aqueous solutions to obviate their explosive tendencies. This form of shipping was very costly because of the bulk and the weight of the contents and the water. Also, because of their potential and actual dangersit was'necessary that the chlorite and bromate neutralizers be present in relatively weak concentrations. This factor required the use of very large amounts of the neutralizer solutions, so that all the waving lotion can be rendered inactive. Even in weak solutions, however, hazards still remain.

By the addition of urea or sodium lactate to bromate and chlorite neutralizers it is no longer necessary that such neutralizers be transported as aqueous solutions. Now they may be shipped in the form of a powder, an emulsion or a clear solution, the first mentioned form being the most practical from a commercial point of view. It eliminates a major cost of shipping, insures against loss from breakages, permits facile and inexpensive packing, requires less storage space and allows the user to form a fresh solution at her convenience.

The reagents combined in powder form blend sulficiently well so that the powdered neutralizer may become clear solutions or emulsions upon the further addition of water. It is not essential that a thickening agent be added to the emulsion powder. We prefer to do so, however, as the emulsion is generally formed only a short While before it is to be used, and the agent will add body immediately. The amount of thickening agent, such as ammonium chloride, or other agent, added to the solution depends upon the consistency desired. The thickening and wetting agents, such as Dupanol (sodium lauryl sulphate) are also utilized in clear solution powder. These, too, may be added in amounts corresponding to the desired viscosity. Usually this is less than 5% of the solution. Also, coloring agents and/or perfume may be added to the emulsion.

Typical emulsifying agents which may be incorporated in the neutralizer are Clearol (liquid petrolatum), Lanagene (polyoxyalkylene lanolin), and 62135 (polyoxyethylene lauryl alcohol).

Advantageously, therefore, the addition of urea or sodium lactate to chlorite or bromate neutralizers eliminates the cost of transporting the neutralizer, as well as eliminating the danger thereof.

In addition'to the advantages obtained in regard to the transportation of the neutralizer further advantages may be obtained in regard to the use of the novel neutralizers. One important factor is the fact that complete oxidation of the reduced hair is obtained. It is now possible to use concentrations of. bromates and chlorites. which provided a complete oxidation of the waving lotion. It is therefore possible to complete neutralization in 2 or 3 minutes. As a general rule, it is best to wait about 5 minutes before rinsing the hair with water. In this period the operator will be certain that every curl, no matter how large or small, thickly or sparsely wrapped, will be completely neutralized. Actually, the bromate or chlorite neutralizer containing sodium lactate or urea may be kept on the hair indefinitely without injuring the hair or scalp. Once it has performed itsfunction in fixing the hair, however,..there is no need for further contact with the hair.-

There isa further commercial advantage in the use of novel neutralizers ofbromates and ohlorites. contianing sodiumlactate or urea, and that is with respect to the time saving. aspect efiectuated bytheir use. These neutralizers will not irritate the hands of the operator, so that she maywork unhampered by gloves. This is more than a matter of convenience. Attimes the waving lotions remain -on the operators hands, as she may be giving several waves per day, and the drying lotion may produce irritation or sorenessof her hands. This can be averted entirely in our process, as the operators hands can be neutralized simultaneously with the hair, with no possibility that the cure will be worse than the ailment.

Although the foregoing discussed novel neutralizers are discussed with respect to cold permanent waving, theiruse is by no means limited. Any systemof waving which utilizes an oxidizing and neutralizing procedure may be accomplished by our invention. Furthermore, it is not restricted to waving hair. The fixing process of hair which has been softened by a reducing agent, in order to remove excess curl, may also utilize our invention.

Specific examples will now be given of our novel neutralizers in the form of powders, emulsions and solutions. The percentages mentioned in the examples are all on a weight volume basis. An example will also be given of the novel neutralizing process utilizing a typical composition in accordance with our invention.

Example I A clear solution powder may be prepared by mixing 3% Dupanol and 4% of ammonium chloride to which has been added 2.5 moles of urea and 1 mole of sodium bromate, and pulverizing the entire mixture.

Example 11 An emulsion powder may be prepared by mixing 1% 62135, 0.7% cetyl alcohol, 0.2% lauryl alcohol, 2.7% urea, 1 mole of sodium chlorite and 0.5% Viscarin.

Example 111 An emulsion may be prepared by adding 0.55% of G2l35, 0.7% cetyl alcohol, 0.2% lauryl alcohol and water (q.s.d. to 1,000 ccs.) 2.7 mole of urea and 1 mole of sodium bromate are then added to the formed emulsion.

Example IV An emulsion may be prepared by adding 1% G2l35, 1% cetyl alcohol, 0.5% lauryl alcohol and distilled water (q.s.d. to 1,000 ccs.), 2.1 mole of sodium lactate and 1 reasonable period of time.

mole of sodium bromate are then added to the formed emulsion.

. Erample .V

I A clear solution may beprepared by adding 3% Dupanol, 4% ammonium chloride and distilled water (q.s.d. to 1,000 ccs.). To this solution are added 2.5 moles of urea and one mole of sodium bromate.

Example VI This example illustrates the process for carrying out the novel neutralization employing sodium lactate or from within the scope oi, the accompanying claims without departing fromthe principles 'of the invention and,

without sacrificing its chiet advantage;

The foregoing application isa continuation-impart application of Serial Noi 709,096, filed November 12, 1946,

now abandoned.

We claim: I I. A process for permanently changing the configuration of hair on the living human scalp without damage to the hair, including the steps of imparting the desired configurationto the hair, treating the hair with a mer'cap- 7 tan permanent waving solution, and subsequently treatcordance with Example III is then applied to the wound curl.' In a few minutes the hair is unwound, rinsed with Water and ready to be placed in the patrons favorite hair style. l i

We have also found that the presence of sodium nitrite in a neutralizer accelerates its neutralizing activity. It is particularly remarkable with respect to the reaction of the bromates. Sodium nitrite renders the previously inert chlorate and perchlorates effective as neuta'rilzers alone or in combination with other oxidants, such as sodium bromate or sodium chlorite. One part (by weight) of sodium nitrite is suflicient to accelerate as much as 25 parts of sodium bromate and 50 parts of sodium chlorate or perchlorate, so that neutralization occurs within a An example of a. neutralizer containing sodium nitrite is now given hereinbelow.

Example VII 0.55% 62135, 0.7% cetyl alcohol, 0.2% lauryl alcohol, and water (q.s.d. to 1,000 ccs.) are added together to from a base. To this base is added 2.5 moles of urea, 1 mole of sodium bromate, and 0.77 mole of sodium nitrite. I

The invention in its broader aspects is not limited to the specific steps, compositions, combinations and improvements described but departures may be made thereing the hair with a neutralizing solution comprising a bromate and an additive consisting of urea, said urea being present in amolar concentration of about l5 parts,

per part of bromate.

2. A process as defined inclaim 1 wherein the bromate is sodium bromate.

3. A process as defined in claim'l wherein the bromate is calcium; bromate. i V i 4. A process as defined in claim 1 wherein the bromate is potassium bromate.

5. A neutralizing solution for fixing mercaptan treated hair comprising a solution of'bromate and an additive consisting of urea, said ureabeing present in a molar concentration of about L5 parts per part of brornate.

References Cited in the file ofthis patent UNITED STATES PATENTS OTHER REFERENCES 7 Taylor et al.: Sodium Chlorite, Properties and Reactions, Ind. Eng. Chem., July 1940, pp. 899-903.

Gregory: Uses and Applications of Chem. and Related Materials, 1939, Reinhold Pub. Corp., N.Y., p. 630.

Claims (1)

1. 5. A NEUTRALIZING SOLUTION FOR FIXING MERCAPTAN TREATED HAIR COMPRISING A SOLUTION OF BROMATE AND AN ADDITIVE CONSISTING OF UREA, SAID UREA BEING PRESENT IN A MOLAR CONCENTRATION OF ABOUT 1.5 PARTS PER PART OF BROMATE.