US 2688972 A
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Patented Sept. 14, 1954 PROCESS FOR PERMANENTLY WAVING H MAN HAIR Alfred E. Brown, Takoma Park, Md., assignor to The Gillette Company, a corporation of Delaware N Drawing. Application November 20, 1951, Serial No. 257,433
This invention concerns a process for imparting a permanent Wave to human hair without the use of heat.
It has been heretofore proposed to cold wave human hair by a procedure in accordance with which the hair, while wound on curling rods, is treated with a solution of an agent capable of rendering the hair plastic through reduction of the disulphide bonds in the hair keratin. These bonds are later restored, with setting of the hair in the configuration determined by the curling rods, through application to the hair of a so-called neutralizing solution, normally an aqueous solution of hydrogen peroxide, sodium perborate or sodium bromate, such solution being applied in increments with intervening working period of from 5 to minutes, the last increment being applied after the hair has been unwound from the curling rods.
While the described process provides a generally acceptable wave, the requisite neutralization step is a troublesome feature, both because it involves considerable work by the user and because, unless the neutralizing is carefully and properly done, the wave may be seriously impaired. Significantly, a large percentage of reported adverse results with the process has been directly traceable to improper neutralization of the reduced hair, stemming from impatience on the part of the applicator who, in the case of home use of the process, is frequently the recipient of the wave as well. The neutralizing operation is especially difiicult to perform in the case of children due to their natural restlessness, which virtually precludes proper application of the solution. In any case, because of the difiiculty of penetrating a wet wrapped tress with the neutralizing solution, an insufiicient amount of the solution penetrates to the tips of the Wrapped tresses, and undue relaxation of ringlet curl often occurs on this account.
As indicated, the principal object of my invention is to provide a cold waving process in the execution of which the use of a neutralizing solution is not required. Another object is to provide such as process which is much simpler to perform than the prior process and which is relatively foolproof. A further object is to provide a process whereby the strongest Wave result can be attained with minimum chemical change of the hair. A still further object is to provide a process in which the hair following impartation of the wave is neutralized automatically. Still another object is to provide a process allowing for the employment of curling rods of a diameter enabling styling of the hair as an incident of the drying period. A still further object of the invention is to provide a process whereby the hair may be permanently waved in the form of pin curls. Still another object is to provide a process which gives extremely tight ringlets without hair damage.
Additional and corollary objects of the invention will appear as the description proceeds.
My invention stems from the fundamental discovery that in the cold waving of hair it is unnecessary that the disruption of the disulphide linkages in the hair keratin by the hair-reducing agent and the development of the wave by plastic flow proceed concomitantly, as previously supposed. In other words, I have found that it is possible to develop the wave essentially as a second step following substantially complete arrestment of the chemical action. And I have further found that when this is done, satisfactory wave results can only be achieved if restoration of the disulphide linkages is brought about gradually by simple aerial oxidation rather than efiected rapidly through employemnt of a neutralizing solution.
In accordance with my process, the reducing chemical is applied to the hair as before, but it is left on the hair in full strength for substantially less time-seldom, if ever, for more than half the time previoustly considered necessary for home waving. Thereafter, and before full development of the final wave the solution is diluted in situ on the hair, which may be wound or curledeither on rods or in a pin-curl configuration, the degree of dilution being such as to preclude further substantial reducing or chemical action of the reducing chemical on the hair. The hair with the diluted solution thereon is maintained on the curling rods or in the pin-curl configuration through a period of time sufficientto fully develop the wave and to insure substantially complete restoration of the normal disulphide linkages through aerial oxidation, the wound hair during this period being kept adequately open to the atmosphere. As the final step of the process, the hair is unwound and, if it is not already dry, wrapped into pin curls for any desired style.
Important differences between the present invention as set forth above and the prior art are that I dilute the reducing chemical prior to full development of the final wave instead of at or after full development of the final wave in order to preclude further substantial chemical action of'the reducing chemical on the curled hair, and
I maintain the hair in wound form for a period of time sufiicient to insure substantial aerial oxidation of the hair for further development of the wave, and after the wave is in permanent fully developed final form, I then unwind the hair.
My invention is novel not only in concept but also in terms of the waving results it affords, which are generally superior to those obtained by prior methods. It is important as emphasizing the difierence between the earlier processes and the process herein that an acceptable wave is not produced when the old processes are practiced without employment of a neutralizing solution or when in the practice of my process the hair is subjected to the action of a neutralizing solution prior to substantial aerial oxidation of the hair. Whereas in the earlier processes essentially all of the necessary plastic flow occurs while the reducing solution is on the hair in full strength, in my process the plastic flow occurs, for the most part, after most of the reducing agent has been removed.
Although solutions of other hair-reducing agents may be used in the practice of my invention, I prefer to use an alkaline solution of a mercaptan. Especially good results have been attained using an aqueous alkaline solution of ammonium thioglycolate. The concentration of the ammonium thioglycolate in the solution and the pH thereof will vary depending on the Waving characteristics of the particular hair, i. e., the ease with which the hair may be waved, the diameter of the hair shafts, whether the hair has been dyed or bleached, etc. Ordinarily, the solution is made 0.5 to 0.8 N in respect of the ammonium thioglycolate and its pH is so adjusted with ammonia that it lies within the range 9 to 9.5. However, acceptable waves can be produced using solutions not conforming to these .limits. Thus, with proper adjustment of the mercaptan concentration, which may be as low as 0.4 N, a solution having a pH as high as 9.7 may be employed with good effect. Conversely, using a solution 0.8 to 0.85 N in respect of the mercaptan, satisfactory results can be attained in some cases at a pH as low as 6.7.
As exemplary of other mercaptans or thiols applicable to the invention may be mentioned: the various amides of thioglycolic acid, amines such as fl-thioethylamine, hydrox mercaptans as ii-hydroxyethanethiol, mercaptans containing ketone, ether or ester groups, e. g., monothiodimethyl ketone, c-mon'othiodiethylether, ethyl thioglycolate, etc., and mercaptans containing sulphonic acid groups such as mercaptoethanesulphonic acid and 3-mercapto-2-hydroxypropanesulphonic acid.
The reducing solutions employed according to the invention generally include, in addition to the hair-reducing chemical, a perfume, a wetting agent, and normally an agent serving to render the solution opaque, with improvement of its appearance. If desired, the solution may further contain a urea compound and/or an ammonium salt.
In the preferred practice of the process the solution is applied both before and after the hair is wound. Curlers, when used, may have any suitable form, but are best manufactured of a material resistant to the action of the solution. Flexible curlers ar obviously advantageous from the standpoint of comfort where the individual receiving the wave proposes to allow the hair to oxidize slowly overnight following the dilution step. Drying time may be reduced by blotting each curl, as with a towel, immediately after the dilution.
It is not necessary that the hair be dried on the curlers (or with the pins in place in case of a pin-curl wave), but it is essential, as previously indicated, that the hair be left in the wound condition subsequent to the dilution long enough to insure essentially complete development and fixing of the wave. Although a drier may be used once the wave has become fixed, it is generally best to let the hair dry naturally.
It is believed that the development of the wave and the oxidation process are normally complete in from 2 to 3% hours, but it is recommended that the hair be left in the Wound condition following the dilution step for not less than 4 hours. At such time, the hair may be sufiiciently damp that it can be unwound and Wrapped into pin curls without rewetting. If rewetting is necessary, the hair can be moistened either before or after it is unwrapped. Satisfactory results are assured in substantially any case if the hair is allowed to go to complete dryness while in the wound form. Naturally, the total time elapsing before the hair is completely dr is determined by the ambient temperature and relative humidity, the thickness of the hair and by the nature of th curls, i. e., the more open the curl the faster the drying time.
Reverting to the initial step of the process, it should be stated that the length of the working period between application of the reducing solution and its dilution in situ on the wound hair is determined primarily by the strength of the solution and the character of the hair. In general, the stronger the solution, the shorter the period of time necessary for processing prior to dilution. As previously indicated, an advantage of my process resides in the fact that the stronger lotions may be used relatively more safely.
Using ammonium thioglycolate solutions of the characteristics previously indicated the working period may vary from 10 minutes to 30 minutes. Usually the solution is applied to the hair both before and after the hair has been wound into the desired configuration.
The purpose of the dilution of the solution on expiration of the working period is to avoid any further significant chemical action. Normally the dilution is efiected by means of a conventional bathroom spray, although pitchers of water may be poured through the curls if a spray is not available or the head may be held under a faucet. Optimum results are generally achieved if the degree of dilution is equivalent to that resulting when the head is kept under a spray for about thirty seconds to one minute, but this period is not critical.
When in the practice of my process the hair is waved in the form of pin curls, with or without the use of devices aiding in the formation of such curls, the hair is styled as well as waved in one operation.
.An important advantage of my process resides in the fact that simultaneous waving and styling of the hair can also be accomplished using curling rods. For this purpose I prefer rods manufactured to a diameter of about 0.2 toabout 0.5 inch. Rods of this relatively large diameter cannot generally be used successfully in the prior procedures because impractical time .periods are then necessary to achieve even weak unacceptable curls (assuming a waving solution of safe strength).
5. Better lasting waves are obtained due to the more complete fixing of the curls.
6. An improved ringlet curled pattern is obtained, the pattern being manifested even in the heart of the curl.
'7. Themanual labor required in the giving of a wave is greatly reduced.
8. A stronger wave is achieved, yet without the use of harsh waving solutions over prolonged periods.
9. The waving of childrens hair is made much less of a problem.
My invention is illustrated by the following specific examples, which are in part comparative. It is understood that these examples will not be taken as in any way limitative of the scope of the invention.
EXAMPLE 1 Test tresses of natural hair cut from representative subjects were shampooed, rinsed, towel blotted to remove excess moisture, and treated with a lotion of the following composition:
Ammonium thioglycolate 0.5 N. Excess ammonium hydroxide 0.5 N. (sufiicient to give pH of 9.4).
Wetting agent 0.3%.
The tresses, wet with lotion, were wrapped on conventional curling rods using end papers and the wrapped tresses individually re-saturated With lotion. After a 30-minute processing period the tresses were divided into three groups,A, B and C. Tresses A were rinsed with water, unwrapped and allowed to dry; tresses B were sprayed with water and allowed to dry on the rods; tresses C were treated on the rods with a commercial neutralizer solution (sodium perborate), unwrapped and allowed to dry.
The tresses were rewetted and tested for strength of curl imparted, the test being repeated in each case after repeated shampooing. The results were as follows:
Wet Curl Strength Tresses ii++ i++ '6 sequence of the five shampoos. Moreover, the curl pattern held up much better. I
The properties of the waved hair. in the case of tresses B difiered little fromthe properties of the unwaved hair, as shown below:
Cystine Content 20% Index (Percent) Tresses Untreated 17. 5 1.00 Waved, rinsed, dried on rod 17. 9 0.89
The 20% index is a ratio of the amount of energy required to stretch an individual hair 20% after the wave compared to that required to stretch the hair the same amount prior to the wave and serves, with the cystineanalysis, as a measure of fiber modification.
EXAMPLE 2 The hair was shampooed in the usual manner and rubbed with a towel to remove excess moisture. An aqueous waving lotion of the following composition was used:
Tresses of the hair were moistened with the lotion and wrapped on rods using conventional end papers. After the head was wrapped, each of the curls was re-saturated with lotion. The lotion was allowed to work for 15 minutes. The hair was then held under a spray for thirty seconds. Excess moisture was removed by blotting the hair with a'dry towel, and the curls allowed to dry. After drying the hair was unwound and the curls were combed and brushed. Alternatively, depending on the hair style required, the hair may be wet out, wrapped in pin curls with water, and styled as desired.
EXAMPLE3 An aqueous waving lotion of the following composition was used:
Ammonium thioglycolate 0.7 N Excess ammonium hydroxide 0.5 N (sufflcient to give pH of 9.15).
Wetting agent 0.3%
The hair was shampooed in the usual manner and rubbed with a towel to remove excess moisture. Tresses of the hair were then moistened with the lotion and wrapped into pin curls using the fingers. If desired, any type of pin-curling gadget, of which many are available, may be used. After all of the curls were wrapped and pinned, they were re-saturated with the waving lotion. The hair was allowed to process for about 25 minutes, then held under a spray as before and towel blotted. After the hair was dried, it was combed out and brushed. In this manner, the hair is waved and styled in one operation.
The lotion in this case contained only ammonium thioglycolate and ammonium hydroxide, the latter in an amount suificient to give a pH of 9.6. The lotion was 0.5 normal in point of the ammonium thioglycolate.
The hair was processed with the solution for 15 minutes on rods of conventional diameter,
.7 rinsed, allowed to remain on the rods for 4hours subsequent to the rinsing, unwound and unwrapped into pin curls. A very satisfactory wave resulted.
, In such a lotion other chemicals such as mono- 'ethanolamine, ethylene diamine, or sodium hy- 0.5 N ammonium thioglycolate 1.5 M urea 08 N ammonium sulphate Ammonium hydroxide added to pH 9.35
The lotion was left on the hair (wrapped on conventional curlers) in full strength for 20 minutes, whereafter the'hair was rinsed and allowed to dry for 5 hours before it was unwrapped. An excellent wave resulted.
EXAMPLE 6 The following lotion was used in the waving of bleached hair: 0.4 N ammonium thioglycolate 0.3 N ammonium sulphate Ammonium hydroxide to pH 9.1
The processing time was minutes, while the hair after dilution of the lotion was allowed to remain on the rods for 6 hours before being unwrapped. An acceptable wave was achieved without any noticeable hair damage, such as caused by conventional lotions.
EXAMPLE '7 Each of the following lotions was found suitable for use in the practice of the new process:
, Lotion I 0.6 N ammonium mercaptoethanesulphonate Ammonium hydroxide to pH 9.3 Process for minutes, rinse, dry for 6 hours.
Lotion II 0.5 N cystine hydrochloride 2.5 M urea Ammonium hydroxide to pH 9.35 Process for minutes, rinse, dry.
Lotion III 0.55 N ammonium thioglycolate 8 1.6 N ammonium carbonate Ammonium hydroxide to pH 8.65 Process for 25 minutes, rinse, dry for 4 hours,
unwrap, set into pin curls.
Lotion IV 0.5 N ammonium N- (a-mercaptoacetyl) -p-am.ino-
salicylate Ammonium hydroxide to pH 9.55 Process for minutes, rinse, dry.
EXAMPLE 8 A lotion especially adapted for the waving of childrens hair has the following composition:
0.7 N ammonium thioglycolate Ammonium hydroxide to pH 9.1
This lotion should be left on the hair in full strength for about 35 minutes before dilution. If conventional rods are used and the resultant hair curls are tighter than desired, the same may be wet out and the hair set in pin curls.
1. Method of imparting a permanent wave to human hair comprising applying to the hair a solution of a chemical agent capable of splitting the disulfide linkages in hair keratin, permitting the solution to act on the hair with the latter in wound curled condition to split said linkages and soften the hair, diluting the solution in situ on the wound curled hair prior to full development of the final wave to preclude further substantial chemical action of the agent on the curled hair, maintaining the hair in wound form before full development of the wave for a period of time sufficient to insure substantial aerial oxidation of the hair and to further and fully develop the wave, and when the wave is fully permanent and in final form, unwinding the hair.
2. The method as set forth in claim 1 wherein the chemical agent is ammonium thioglycolate.
3. The method as set forth in claim 1 wherein said period at time is at least two hours.
References Cited in the'file of this patent UNITED STATES PATENTS Number Name I Date 2,405,166 Reed Aug. 6, 1946 2,479,382 Mace Aug. 16, 1949 2,540,980 Den Beste Feb. 6, 1951 2,577,710 McDonough Dec. 4, 1951 FOREIGN PATENTS Number Country Date 117,071 Australia June 17, 1943