This document describes a preparation and process for permanently changing the shape of hair, such as imparting a permanent wave, using a reducing solution containing a mercaptan (such as thioglycollic acid), a sulphite, and formamide or a substituted formamide (such as urea). Applying the solution to hair wrapped in curlers and heating it to 40-60°C (tepid waving) allows the concentration of mercaptan to be substantially reduced compared to conventional preparations while still effectively changing the hair shape. The preparation pH is preferably 9-10 and concentrations of ingredients like mercaptan, sulphite, and formamide or substitute are provided.

1. * GB780037 (A)
Description: GB780037 (A) ? 1957-07-31
Improvements in or relating to the treatment of hair
Description of GB780037 (A)
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The EPO does not accept any responsibility for the accuracy of data
and information originating from other authorities than the EPO; in
particular, the EPO does not guarantee that they are complete,
up-to-date or fit for specific purposes.
COMPLETE SPECIFICATION
Improvements in or relating to the Treatment of Hair
We, UNILEVER LIMITED, a company registered under the laws of Great
Britain, of Port
Sunlight, in the County of Chester, England, do hereby declare the
invention for which we pray that a patent may be granted to us and the
method by which it is to be performed, to be particularly described in
and by the following statement:
This invention relates to the treatment of hair and more particularly
to permanently changing the shape of hair, such as by imparting a
permanent wave to the hair or straightening the hair.
Nowadays the shape of hair is generally changed permanently at room
temperature by employing, as a reducing agent, an alkaline preparation
of a mercaptan, such as thioglycollic acid, followed by a neutralizing
or oxi- dizing agent, such as potassium bromate. It has been
postulated that large amounts of a swelling agent, such as urea or
formamide, may be beneficial in the operation of permanendy changing
the shape of hair when added to the reducing agent. Other reducing
agents. such as a substantially neutral solution cf alkali metal
bisulphites, have also been proposed to change permanently the shape
of hair without the use of heat, but in the absence of heat large
amounts of a swelling agent have to be incorporated with these other

2. reducing agents so that a satisfactory permanent change of the shape
of the hair may be obained. Usually, he process for permanently waving
hair consists in applying to the hair the reducing agent before or
after the hair has been wrapped in curlers, and allowing the reducing
agent to act on the keratin of the hair. The hair is then treated with
the neutralizing or oxidizing agent beware or after rinsing it with
water.
Surprisingly5 it has now been found that improved results in
permanentty changing the shape of hair may be obtained by employing as
a reducing solution a preparation including a mercaptan, a sulphite
and formamide, or a substituted formamide as defined herein, such as
urea. ldercaptans which may be used in place of or in addition to
thioglycollic acid are, for example, beta-mercapto-ethane-sulphonic
acid or glyceryl mono-mercaptan. The mercaptans are preferably used as
alkali metal, ammonium or amine salts although they may oe salts of
other alkalis, such as alkaline earth metal hydroxides.
Tue term " sulphite" whenever usad hereafter is intended to extend to
the sulphites, bisulphites and meta-bisuiphites, and in particular to
the sulphites, bisulphites and metabisulphites of the alkali metals
and ammonia.
Accordinglv, the present invention provides a preparation for
permanently changing the shape of hair which includes a mercaptan, a
sulphite and formamide or a substituted formamide as hereinbefore
defined.
The invention also provides a process for permanently changing the
shape of hair which mciudes applying to the hair a preparation
including a mercaptan, a sulphite and formamide or a substituted
formamide as hereinafter defined.
Of the substituted formamides according to the present invention, the
preferred compound is urea. Other substituted formamides are acetamide
or the ethanol formamide. For the purpose of the present specification
the term
substituted formamide " also includes thiourea, but apart from
thiourea does not include compounds derived from formamide other than
by simple substitution of the carben-hydrogen atom in the parent
molecule.
Conventional preparations for permanently changing the shape of hair
generally have the mercaptan at relatively high concentrations, and
therefore require skilful application to the hair so as to obtain the
most favourable results. in formulating such a preparation it is
generally desirable to keep the concentration of mercaptan to the
minimum with which effective hair shaping can be performed. According
to the present invention, the concentration of the mercaptan may be
substantially reduced over the concentrations found in conventional

3. preparations.
The hair shaping preparations according to the present invention may
be applied to a head of hair under temperature conditions normally
prevailing close to the human skin, that is, from 30 to 35 C. At
elevated temperatures of from about 40 to about 60 C. the activity of
the hair shaping preparation according to the present invention is
apparently increased, so that the concentration of the mercaptan
and/or the sulphide may be further reduced without affecting the steed
of operation, intensity or permanency of the shape to be imparted to
the hair. Alternatively, the time required for permanently changing
the shape of the hair may be reduced. Elevated temperatures of from
about 40 to about 60 C. are generally obtained under a hair drier, and
for the purposes of this specification temperatures from about 40" to
about 60 C. will hereinafter be referred to as tepid", and the process
of changing the shape of hair at these elevated temperatures as
"tepid-waving". For maximum efficiency of the preparations according
to the present invention, it is therefore preferred to use these
preparations under tepidwaving conditions. The invention will be
further illustrated with reference to these tepid-waving conditions,
it being understood that a person skilled in the art is able to adjust
the conditions in such a way as to adapt the invention, for example,
to cold-waving.
In another aspect the present invention provides, therefore a process
for tepid-waving which includes applying to the hair a preparation
including a mercaptan, a sulphite and formamide or a substituted
formamide as herein defined.
Under tepid-waving conditions, that is, at temperatures of from about
40 to about 60 C. the concentration of mercaptan employed according to
the present invention is usually less than 10%, and may be as low as
1.5%.
Generally, the mercaptan is present at a concentration of from 4 to
8.5%, the range of from 4 to 6.5)0, being preferred. The sulphite
concentration will generally be within the range of from 2.5 to 6%,
from 3.0 to 4.5% being preferred. Concentrations up to 10% and as low
as 1.5% may, however, be used with advantage under certain
circumstances.
The above percentages and those given hereinafter are all percentages
by weight.
Formamide or substituted formamides, and in particular urea, promote
the swelling of the hair but it has been found that proportions of any
of these compounds substantially in excess of 10S: will sometimes give
unfavourable results in tepid-waving. These unfavourable results, such
as a harsh appearance of the hair after waving, may in some instances
be counteracted bv adding to the preparation from about 1 to about 2

4. ,O of a vegetable or mineral oil, or alternately from about 0.1 to
about 0.3 of a cationic surface-active agent, such as lauryl dimethyl
benzyl ammonium chloride.
Generally, however, concentrations of from 3 to 6'., of formamide or a
substituted formamide are preferred, in which case the addition of oil
or cationic agent will not be required.
Concentrations of 2.5,0, and as low as 1.5%, of formamide or a
substituted formamide may be used under certain circumstances.
The pH of the preparations according to the invention may be critical
for achieving besr results. For the purpose of the present invention
the pH must always be at least 7. Most favourable conditions for
changing the shape of hair appear to exist when the preparations have
a pH of from 9 to 10. The pH of the preparations is advantageously
adjusted by means of ammonia, but other alkaline sus stances such as
sodium hydroxide may also be used for this purpose.
In giving a tepid-wave, procedures similar to the following, which may
be suitably modified, may be used. The hair is moistened with the
preparation according to the invention, and wound on a curler. After
applying a further amount of the preparation according to the
invention to the hair thus wound on curlers, the head of hair is
covered with a plastic cap. The hood of a pre-heated electric drier is
then placed over the head of hair, so as ro raise the temperature of
the preparation to from about 40c to about 60 C., and maintained in
position for a period of from 5 to 30 minutes, according to the
strength of curl required. The head of hair is then rinsed for
approximately three minutes with water, and is thereafter exposed to
the atmosphere for some time to facilitate aerial oxidation.
Alternatively, the rinsing step may be followed by applying to the
hair a neutralising agent, such as sodiurl perborate or hydrogen
peroxide.
Finally, the hair is set and dried in the usual manner.
Other ingredients, such as perfumes and colouring material normally
present in preparations for changing the shape of hair, may also be
added. In particular, some of the water in the preparations may be
replaced by alcohol.
The following examples illustrate the invention:
EXAMPLE 1
Switches of identical hair were prepared, wound on curler and each
treated with an excess of one of the following preparations.
After shaking off excess moisture, the switches were processed in a
thermostatically controlled oven at 37 C. for 15 and 30 minutes.
Preparation 1 2 3
Ammonium thioglycollate (100%) 5.33 4.15 1.78 Ammonium sulphite - 3.45
-

5. Sodium metabisulphite - - - - 1.5 1.5
Urea - - - - - - - 6.0 6.0 6.0
Free ammonia (100%) - - - 1.56 0.78 0.33
Water - - - - - - - q.s.100 q.s.100 q.s.100 pH - - - - - - - - 9.70
9.40 8.84
Strength of curl - - - - - tight tight slack
Following the heat treatment the switches of hair were rinsed with
water and then neutralised with 0.6% hydrogen peroxide solution.
The curlers were removed from the switches, which were rinsed again
with water and allowed to dry in a vertical position.
Nodifferences were observed in the strength of curl produced on
switches of hair treated for 15 or 30 minutes respectively with the
same preparation.
When the switches of hair were not processed under " tepid-waving "
conditions but were allowed to undergo a so-called "cold- wave"
treatment with any one of the above preparations, the time required
for obtaining a good strength of curl varied from 45 to GO minutes.
EXAMPLE 2
The following are examples of preparations which may be used for
permanently changing the shape of hair.
Solution 1
Ammonium thioglycollate
(100%) - - - - - 5.33
Ammonium sulphite - - 3.45
Urea - - - - - - 6.0
Free ammonia (100%) - - 1.56
Perfume - - - - - 2.00
Lauryl dimethyl benzyl
ammonium choride - - 0.20
Water q.s. - - - - - 100.00
Solution 2 %
Ammonium thioglycollate 4.15
Sodium metabisulphite - - 1.50
Urea - - - - - - 6.00
Free ammonia (100%) - - 0.78
Perfume - - - - - 2.00
Emulsified mineral oil - - 6.0fl
Water - - - - - q.s. 100.00
What we claim is: -
1. A preparation for permanently changing the shape of hair which
includes a mercaptan, a sulphite and formamide or a substituted
formamide as herein defined
2. A preparation according to Claim 1, in which the mercaptan and the
sulphite have concentrations of from about 1.5 to about 100/o by

6. weight.
3. A preparation according to Claim @ or
Claim 2, in which the mercaptan has a concentration of from 4 to 8.5 %
by weight.
4. A preparation according to any one of the preceding claims, in
which the mercaptan has a concentration of from 4 to 6.5% by weight.
5. A preparation according to any one of the preceding claims, in
which the sulphite has a concentration of from 2.5 to 6% by weight.
6. A preparation according to any one of the preceding claims, in
which the sulphite has a concentration of from 3 to 4.5 o,/o by weight
7. A preparation according to any one of the preceding claims, in
which the formamide curl substituted formamide as herein defined, has
R concentration nf from 1.5 to 10% by weight
8. A preparation according to any one of the preceding claims in which
the formamide or substituted formamide as herein defined, has a
concentration of from 3 to 6% by weight.
9. A preparation according to any one of the preceding claims in which
the mercaptan is ammonium thioglycollate.
10. A preparation according to any one of the preceding claims in
which the sulphite is ammonium sulphite or sodium metabisulphite.
11. A preparation according to any one of the preceding claims in
which the zubstituted formamide is urea.
12. A preparation according to any one of the preceding claims which
has a pH of from 9 to 10.
13. A "tepid-waving" preparation substanrally as herein described.
14. A process for permanently changing the shape of hair which
includes applying to the hair a preparation including a mercaptan, a
sulphite and formamide, or a substituted l mamide as herein defined.
15. A process for tepid-waving as herein defined which includes
applying to the hair a preparation including a thioglycollate, a
sulphite and formamide or a substituted formamide as herein defined,
and thereafter raising the temperature of the preparation so applied
to the hair to from about 40 to about 60 C.