Permanent wave system using ammonium bisulfite prewrap

This invention relates to an improvement in the method of treating hair in which water wet hair is wrapped around rollers, a mercaptan-containing solution is applied to the hair on the rollers, and the mercaptan-wetted hair is thereafter neutralized with an oxidizing agent. This improvement comprises wetting the hair prior to wrapping it with an aqueous solution of a prewrap agent selected from the group consisting of alkali metal and ammonium sulfites and alkali metal and ammonium bisulfites. These prewrap agents are present at about 0.1 to about 1.0 Molar, at a pH of about 6.5 to about 7.5 and cleave no more than about 5 percent of the hair disulfide bonds before the mercaptan-containing solution is applied.

BACKGROUND OF THE INVENTION 
This invention relates to an improvement in hair treatments in which 
moistened hair is placed on rollers or rods (hereinafter "rollers"), hair 
protein disulfide bonds which cross-link the hair are broken by use of 
thiol-containing reagents, and then the disulfide bonds are reformed by 
use of an oxidizing neutralizer which causes the hair to acquire a new 
curl. The improvement of our invention involves the use of a bisulfite or 
sulfite containing aqueous solution which is applied to the hair prior to 
wrapping the hair on the rollers. 
Thiol-containing reagents for hair treatments are those materials which 
contain a free --SH group or mercaptan. Salts of thioglycolate acids and 
thioglycolic acid esters are the reagents which are normally used in such 
hair treatments. Other thiol-containing reagents such as thiolactic acid, 
.beta.-mercaptopropionic acid, .beta.-mercaptobutyric acid, and the like 
are known in the art to be effective. 
While hair treatments with thiol containing reagents used in conjunction 
with hair rollers are most frequently used for waving hair, i.e., putting 
in curl, these reagents may be used with rollers for straightening hair, 
i.e., taking some curl from curly hair. When a tight curl is wanted as in 
waving, curlers of a narrow diameter, such as about 1 cm or less, are 
used. For straightening, curlers of a wide diameter, such as about 5 cm, 
may be used. The improvement of this invention relates to both waving and 
straightening hair, although its primary uses will probably be in the 
field of hair waving. For convenience, the word "waving" is used 
hereinbelow to mean hair treatments which include both waving and 
straightening. Thus, those methods for imparting a tighter curl when a 
narrow diameter roller is used will also impart a looser curl when a wide 
diameter roller is used. 
The process of waving hair is old in the art and will not be explained in 
detail herein. Generally, in such processes, dampened hair is wound about 
a roller or curler and clamped in place. A solution containing the 
mercaptan reagent (waving lotion) is then applied to the hair upon the 
rollers to cleave the disulfide bonds within the hair. After waiting a 
suitable period of time, the waving lotion is rinsed from the hair. The 
hair is then neutralized with an oxidizing reagent which reforms disulfide 
bonds within the hair that had been broken by the thiol-containing 
reagent. It is believed that the reformation of the disulfide bonds within 
the hair is what causes the new wave or curl to be imparted to the hair. 
The curls so imparted will not wash out with water and consequently a curl 
or wave so formed is called a permanent wave. When this process is carried 
out at room temperature, without the use of external heating devices, it 
is called "cold waving." 
Modern, commercial, cold, permanent waving preparations frequently include 
an instruction to wet the hair with the waving solution or lotion prior to 
wrapping the hair upon the rollers. It has been found that such a prewrap 
treatment helps impart a tighter curl to the hair than if water, alone, is 
used to wet the hair prior to wrapping. A problem with such a prewrapping 
procedure however, is that although manufacturers suggest that gloves be 
worn during the wrapping procedure, the person, such as the hair dresser, 
who would do the wrapping usually finds that the use of gloves makes such 
wrapping quite difficult and cumbersome to achieve. As a consequence of 
this difficulty, many such users do not wear gloves during the wrapping 
process. Frequent and/or prolonged contact of the user's hands with the 
waving solution and its thiol containing reagent often causes skin 
irritation and in some cases causes allergic reactions. This is true even 
where the safest thiol-containing reagents, such as thioglycolic acid 
derivatives, are used. Thus, the hair dresser is frequently faced with the 
problems of getting a loose curl when a tight curl is desired because a 
prewrap solution of water was used rather than waving lotion, or of 
getting irritated skin from handling the waving lotion without gloves. 
While the general cold waving process is old in the art, there has been an 
evolution in the pH and constituents of the waving lotion. As originally 
introduced, the waving lotion pH was approximately 9.2 or higher. More 
recently cold waving has been practiced at a pH as low as about 7.6. Still 
more recently so-called "acid" waving has been introduced. The pH of an 
acid waving solution is approximately 6.9 or lower. While the principal 
waving constituent in the older waving lotions was a salt of thioglycolic 
acid, such as ammonium thioglycolate, the acid waving lotions usually 
contain glyceryl monothioglycolate as the principal active ingredient. 
While there are several advantages to using an acid waving system, there 
are also disadvantages. One important disadvantage to these systems is 
that they are more injurious to skin than were the more basic ammonium 
thioglycolate based, waving lotions. Consequently, most manufacturers do 
not suggest using the acid waving lotion as a prewrap solution because it 
is known that some users don't wear gloves during the wrapping step. With 
no prewrapping solution or, in effect, a water prewrapping solution, curl 
tightness often suffers. 
One benefit of our invention is to lessen the contact of the 
mercaptan-containing reagent with the user's hands by providing an 
alternative prewrap solution which does not contain a mercaptan reagent. 
Another benefit of our invention is to provide a prewrap solution which 
will allow the formation of a tighter curl than is possible by using only 
water as the prewrap solution. 
BRIEF SUMMARY OF THE INVENTION 
This invention relates to an improvement in the method of treating hair in 
which water wet hair is wrapped around rollers, a mercaptan-containing 
solution is applied to the hair on the rollers, and the mercaptan-wetted 
hair is thereafter neutralized with an oxidizing agent. This improvement 
comprises wetting the hair prior to wrapping it with an aqueous solution 
of a prewrap agent selected from the group consisting of alkali metal and 
ammonium sulfites and alkali metal and ammonium bisulfites. These prewrap 
agents are present at about 0.1 to about 1.0 Molar, at a pH of about 6.5 
to about 7.5 and cleave no more than about 5 percent of the hair disulfide 
bonds before the mercaptan-containing solution is applied. 
DETAILED DESCRIPTION OF THE INVENTION 
We have found that aqueous solutions containing prewrap agents such as 
sulfite and bisulfite salts are particularly mild to the user's hands when 
used in place of waving lotion in a prewrap solution, and that such 
solutions provide waved hair having a tighter curl than if water alone is 
used as a prewrap solution. The sulfite and bisulfite salts which are 
preferred as prewrap agents in our invention are the alkali metal and 
ammonium salts. These include sodium sulfite heptahydrate, potassium 
sulfite dihydrate, ammonium sulfite monohydrate and the like as well as 
sodium, potassium and ammonium bisulfites and the like. Ammonium bisulfite 
is particularly preferred. 
The concentrations of these preferred prewrap agents in the aqueous prewrap 
solution can range from about 0.1 Molar to about 1.0 Molar. The preferred 
range is about 0.2 Molar to about 0.3 Molar. 
At a given pH, the amount of disulfide bond cleavage is dependent at least 
upon the concentration of sulfite or bisulfite prewrap agents, the 
duration of contact of these prewrap agents with the hair and the 
temperature at which these reagents are used to treat the hair. High 
concentrations, long contact times and elevated temperatures are factors 
which promote increased disulfide bond cleavage. Therefore, these factors 
may be altered or played against each other to produce a desired amount of 
disulfide bond rupture. In practicing the method of our invention, the 
preferred concentration of sulfite or bisulfite, placed on the hair 
without external heating, allows the user a leisurely pace for applying 
the waving lotion so that the lotion is applied before too many disulfide 
bonds are broken by the prewrap agents. 
Although sulfite and bisulfite salts are known in the art for use in waving 
hair, the methods of such use as taught in the art and as practiced herein 
are different. In waving, at least about 15 percent, and preferably about 
20 to about 30 percent of the disulfide bonds are broken by the waving 
lotion, using virgin, European hair as the standard. As practiced in our 
prewrap method, no more than about 5 percent of the disulfide bonds in 
virgin, European hair are broken by the sulfite or bisulfite salts of the 
prewrap solution. While these salts may be used to practice our invention 
at a concentration of about 1 Molar, as is frequently practiced in the 
waving art, the user must work quickly at such concentrations to avoid 
breaking too many disulfide bonds to thereby avoid forming too many Bunte 
salt groups [Protein--SSO.sub.3 --] which remain in the hair after waving. 
Problems associated with excessive residual Bunte salt groups are 
discussed hereinbelow. By using the preferred concentration of about 0.2 
Molar to about 0.3 Molar, the user need not rush as such concentrations 
will not cleave the minimal 15 percent disulfide bonds needed for waving 
within normal working times. 
Another difference between the bisulfite waving art and that of our 
invention is that the sulfhydryl groups (Protein--SH) and the Bunte salt 
groups [Protein--SSO.sub.3 --] formed in either method by the action of 
bisulfite or sulfite ions with the disulfide bonds of the hair protein are 
reformed into disulfide bonds in the conventional waving processes with 
the aid of a fixing step carried out at a pH of about 8 to about 10, while 
in our invention, no such fixing step is used and the hair protein 
disulfide bonds are reformed by the oxidizing neutralizer which is used in 
conjunction with the mercaptan-containing waving lotion. If sufficient 
amounts of Bunte salt groups are present to allow waving to occur, i.e., 
greater than about 15 percent, oxidative neutralization as practiced 
herein leaves the hair harsh to the touch, brittle when dry and spongy 
when wet. However, as practiced by our method, fewer than about 5 percent 
Bunte salt groups are formed prior to application of the waving lotions, 
and, there is little tendency toward harsh feeling, brittle hair after 
oxidative neutralization. 
U.S. Pat. No. 3,644,084 to Hsiung and Wolfram discloses a method for 
reforming hair disulfide bonds broken by sulfitolysis. In their method, 
the hair disulfide bonds are cleaved by use of a sulfite type reagent and 
the bonds are reformed by a sulfur-containing reagent (including a 
mercaptan) present at about 0.02 to 0.3 Molar. In our method, only a small 
amount of the disulfide bonds (less than about 5 percent) are cleaved by 
sulfite reagents, while the great majority of bonds are broken by the 
mercaptan-containing reagent present, as in commercial waving lotion, at 
about 0.5 to about 2.5 Molar. The Hsiung and Wolfram method includes a 
step, not found in our method, in which sulfite reagent is rinsed from the 
hair prior to application of the sulfur-containing reagent. 
Essentially, the Hsiung and Wolfram method starts with a strong sulfite 
treatment (to cleave more than 15 percent of the disulfide bonds) and 
follows it with a weak mercaptan treatment (to reform the already cleaved 
disulfide bonds). In contrast, the instant invention starts with a weak 
sulfite treatment (to cleave fewer than about 5 percent of the disulfide 
bonds) and follows it with a strong mercaptan treatment (to cleave the 
remaining bonds necessary to provide a good wave). 
The Hsiung and Wolfram patent also discloses an analytical method for 
determining the amounts of Bunte salt groups and Protein--SH groups in the 
hair as well as the residual amounts of these groups after reformation of 
the disulfide bonds. The first step of this analytical method is hereby 
incorporated by reference for determining the amount of disulfide bond 
cleavage caused by the prewrap solution of our invention. The ratio of 
disulfide bond cleavage to total disulfide present, as found by the MNP 
method, times 100 percent yields the percent disulfide bond rupture as 
discussed herein. 
Additionally, in bisulfite waving, the usual practice is to treat the hair, 
wound on rods or rollers, with waving lotion, cover the hair with a 
plastic turban for 10 to 20 minutes, rinse, treat the hair with fixing 
lotion, followed by another rinse and then the neutralization step. In our 
method, the moistened hair is simply treated with our prewrap formulation 
to achieve limited disulfide cleavage, wound on rollers and then treated 
with a mercaptan containing waving lotion. 
The preferred pH of the prewrap solutions of our invention is about 6.5 to 
about 7.5. More preferred is a pH of about 6.9 to about 7.0. This 
preferred pH range is also the pH range at which many commercial waving 
lotions, including the acid waving lotions are supplied and thus, there is 
little if any problem of pH incompatibility between the prewrap solution 
and the waving lotion. The prewrap solutions of our invention also have a 
minimal buffering capacity so that if a buffered waving lotion of a higher 
pH is used, the pH of the prewrap solution does not greatly affect that of 
the waving lotion. Because of the bisulfite-sulfite equilibrium, the 
bisulfite ion predominates in solution at pH values less than about 7.2. 
To use the prewrap solutions of our invention, the hair to be waved is 
usually first dampened. This usual dampening is often the result of a 
prior shampoo treatment although such a shampooing is not necessary to 
practice this invention. After such a dampening or shampoo treatment, the 
hair is preferably towelled dry so that it is not dripping wet. An aqueous 
prewrap solution of this invention is then applied to the hair. The 
prewrap solution treated hair is then wrapped upon rollers of the desired 
diameter, and the hair treated with the mercaptan-containing waving lotion 
and oxidizing neutralizer as is the usual practice in the art. Upon 
drying, the curls obtained are tighter than those obtained when water 
alone is used as a prewrap liquid. 
The prewrap solutions used in the practice of this invention are usually 
formulated to contain emulsifiers, conditioners, swelling agents, 
preservatives, perfumes, coloring agents and the like. These added 
materials enhance the effect and appearance of the product and treated 
hair, but are not necessary for the practice of our invention.

The present invention is illustrated by, but not limited to the following 
examples. 
EXAMPLE 1: Ammonium Bisulfite Prewrap Lotion 
A specific ammonium bisulfite containing prewrap lotion was prepared as 
follows: 
______________________________________ 
FORMULA 
Components Percent by Weight 
______________________________________ 
(1) Deionized water 90.00 
(2) Ammonium bisulfite (60%) 
5.40 
(3) Ammonium sulfate 0.50 
(4) Ascorbic acid 0.10 
(5) Ammonium hydroxide to pH 6.5- 
6.8 approx. 1.25 
(6) Ceraphyl 65.sup.1 0.20 
(7) Tween 20.sup.2 0.40 
(8) Fragrance 0.05 
(9) Coloring solutions 0.025 
(10) NH.sub.4 OH to pH 6.9-7.0 
-- 
(11) Deionized water balance 
100.00 
______________________________________ 
.sup.1 An amide formed from mink oil fatty acid and 
1amino-propyl-3,3-dimethyl-3-hydroxyethylammonium chloride. 
.sup.2 Polyoxyethylene sorbitan monolaurate. 
Components 3 and 4 were dissolved in component 1. Component 5 was added 
followed by component 2. Components 6, 7 and 8 were premixed and added to 
the above mixture with agitation. The final components, 10 and 11 were 
added and the entire mixture agitated to ensure homogeneity. 
EXAMPLE 2: Acid Waving Formulation 
Portion A--Glyceryl Monothioglycolate 
Glyceryl monothioglycolate is an item of commerce which typically contains 
about 80 percent by weight glyceryl monothioglycolate, about 1 percent to 
about 6 percent by weight free thioglycolic acid, with the remainder of 
the material being free glycerol. Portion A is packaged separately from 
Portions B and C. 
Portion B--Buffered Base 
______________________________________ 
FORMULA 
Components Weight Percent 
______________________________________ 
(1) Deionized water 
96.05 
(2) Borax 1.00 
(3) Dantoin MDMH.sup.1 
0.10 
(4) Igepal CO 730.sup.2 
0.75 
(5) Fragrance 0.10 
(6) Ammonium hydroxide 28% 
app. 2.00 
100.00 
solution pH is 9.9-10.1 
______________________________________ 
.sup.1 Monomethylol dimethylhydantoin. 
.sup.2 Nonylphenol condensed with ethylene oxide to about 73% of the 
phenol's weight. 
Components 1-5 may all be added together and mixed, component 6 is added 
last and then mixed in thoroughly. 
About 29.4 gm of Portion A are mixed with about 78.0 gm of Portion B to 
yield a buffered, acid waving formulation whose pH is about 6.9. 
Portion C--Oxidizing Neutralizer 
A typical oxidizing neutralizer solution comprises: 
______________________________________ 
FORMULA 
Components Weight Percent 
______________________________________ 
1) Deionized water 92.252 
2) Fatty acid quaternary ammonium complex.sup.1 
1.500 
3) Hydrogen peroxide (35% aqueous) 
6.230 
4) Silicone antifoam agent 
0.010 
5) Phosphoric acid to pH 3.5 
app. 0.008 
100.000 
______________________________________ 
.sup.1 The fatty acid quaternary ammonium complex is a conditioning agent 
which serves to improve the combability of the finished waves. 
Components 1-4 may all be added together and mixed with component 5 added 
last and then mixed in thoroughly. 
EXAMPLE 3: Waving Hair Using A Prewrap Formulation 
Models' heads were shampooed and rinsed in a usual fashion and then 
towelled so that while they were wet, they were not dripping wet. One side 
of their heads was then wrapped (while the hair was wet) on standard 
waving rollers. The other side of the models' heads was treated with the 
prewrap formulation of Example 1 by pouring the formulation onto the hair, 
working it into the hair and then wrapping sections of the treated hair 
onto rollers identical to those used on the water-only treated sides. 
Portions A and B of Example 2 were mixed as discussed in Example 2 and 
applied to the rolled hair on both sides of the heads as soon as the 
wrapping operation was completed (within about 15-45 minutes, depending on 
the speed of the operator and the hair of the model). After a suitable 
time, up to about 30 minutes, depending upon the models' hair type and 
desired curl tightness, the prewrap solution and waving lotion were rinsed 
from the hair. Portion C of Example 2 was added to the rolled hair on both 
sides of the heads. The neutralizer was then rinsed from the hair, and the 
hair dried. Evaluations for curl tightness for each half-head showed that 
those half-heads treated with the prewrap formulations of this invention 
had tighter curls than those treated with water alone. 
While the invention has been described with respect to its preferred 
embodiments, it will be understood by those skilled in the art that 
modifications and variations may be made without departing from the 
invention as defined in the appended claims.