Note: Descriptions are shown in the official language in which they were submitted.
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This inv~ntion rela'~es to a sys~m for the permanent
~aving of hair in which an ammonium thioglycolate solution of
controlled strength is utilized in conjunction ~1ith the appli-
cation of heat at a controlled temperature and for a con-
trolled period o~ time.
The perm~nent waving of hair is commonly carried out
by applying to the hair, while it is wound around rolls, an ~-
aqueous solution o~ ammonium thioglycolate to so~ten the hair
strands, followed by removal of excess thioglycolate solution
and then by application o~ an oxidizing solution to the hair
to neutralize the ammonium thioglycolate solution and to
restore firmness to the hair strands. Substantially all per-
manent wavin~ for home use and much'of the permanent waving
in beauty shops is o~ the "cold wave" type in which no exter-
nal heat is used.- Such permanent waving takes a substantial
time to effect despite the fac~ that relatively strong am-
monium thioglycolate solutions are used.
To reduce the time necessary to effect a permanent
wave external heat may be applied to the hair while it is
wound around the rolls, preferably by the application to each
roll o~ a preheated clamp of sufficient heat capacity to main-
tain the hair within a desired temperature range ~or a suffi-
cient time to permit the ammon.;um thioglycolate to effect its
desired action. ~ith such heat-assisted permanent waving,
ammonium thioglycolate solutions o~ lesser strength are used
than are used in non-heat-assisted permanent waving for hair
of the same type.
Because of the~ rapidity o~ the action o~ the ammon-
.
ium thioglycolate solution when heat-assisted, it is necessary
to control the time o~ its action to avoid overprocessing and
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conse~uent damage to the hair. The operators in such heat-assisted permanent
waving æe instructed to limit processing time but so~.etimes fail to do so.
This invention relates to improvements in a heat-assisted method
for the permanent waving of hair in which an aqueous solution containing
ammonium thioglycolate is applied to hair wound around a roll to wet said
hair, the wetted hair is maintained at an elevated temperature by a heated
clamp holding said hair æound said roll, excess ammonium thioglycolate
solution is then removed and an oxidixing solution is thereafter applied to
said hair to neutralize said ammonium thioglycolate solution, the improvement
which comprises permitting said heated clamp to heat said wetted hair to a
temperature above 120F. and to maint~;n a temperature above 120F. for no
more than 6 minutes, and utilizing as said ammo.nium thioglycolate solution,
a solution of greater strength than is used on similar hair in prior heat-
assisted permanent waving and of lesser strength than is used in prior non-
heat-assisted permanent waving, wherein said ammonium thioglycolate solution
is an aqueous solution selected from a group consisting of solutions having
a thioglycolate content between 9.6 and 9.8 weight percent and a pH level
between 7.5 and 7.7; solutions having a thioglycolate conbent between 2.4
and 2.6 weight percent and a pH level be~ween 9.30 and 9.40; solutions having
a thioglycolate content between 8.4 and 8.6 weight percent and a pH level
between 8.3 and 8.5; or solutions having a thioglycolate content between
0.70 and 0.80 weight percent and a pH of 7.5 to 7.7.
This invention further relates to a permanent waving ccmpositiQn ..
for heat-assisted permanent waving whereby hair wetted by said composition
is maintained at an elevated temperature by a heated clamp holding hair
around a roll, said compositiQn co~prising an aqueous solution selected
from a grcup cQnsisting of solutions having a thioglycolate content between
9.6 and 9.8 weight percent and a pH level between 7.5 and 7.7; solutions
having a thioglycolate content between 8.4 and 8.6 weight percent and a pH
level k#tween 8.3 and 8.5; or solutions having a thioglycolate content
between 0.70 and 0.80 weight percent and a pH of 7.5 to 7.7; said ammonium
thioglycolate solution being of greater strength than is used in prior heat-
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assisted permanent waYing and of lesser strength than is used in prior
non-heat-assisted permanent waving.
In accordan oe with the present invention the heat content of the
clamps and the strength of the ammanium thioglycolate are correlated so that
the clamps cool within the appropriate processing time to a temperature at
which the amm~nium thioglycolate solution loses substantially all of its
processing activity. Specifically, the construction and material of the
clamps and the temperature to which they are preheated are selected to permit
the clamps to heat the wetted hair on the rolls to a bemperture above 120F.
and to mainta m a temperature above 120F. for no more than six minutes and
the strength of the ammonium thioglycolate solution is at a level lower than
that of ammonium thioglycolate solutions used in non-heat-assisted permanent
hair waving systems and higher than that of ammonium thioglycolate solutions
used in prior heat-assisted permanent waving systems.
As is well known, ammanium thioglycolate solutions act on the
keratin~c~o~s protein of the hair to effect the splitting of disulfide bonds
in the protein and the creation of sulfhydryl groups capable of bonding to
each other upon oxidation to re-create disulfide groups. Distortion of the
hair strands by win~ing the hair around the rolls changes the spatial
r~lationship of sulfhydryl groups so that upon oxidation any particular
sulfhydryl group is highly likely to be joined to a sulfhydryl group other
than the one fram which it was originally split, resulting in the formation
of a different molecular structure in the hair strand and thereby permanently
altering its configuration.
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The streneth of an ammonium thioglycolate solution,
or the extent to which it can effect the desired split~ing
of disulfide bond~ ~ithin a given time at a given teMperature
is dependent on both its ar~lmonium thio~l~colate conten~ and
its alkalinity, stronger solutions having higher ammonlu~
thioglycolate contents, higher pH levels, or both
As is well known in the permanent waving art, human
hair varies substantially in the ease or difficulty o~ effect-
ing permanent ~laving and in its susceptibility to damage by
overprocessing, depending on the basic nat~re of the hair and
.
on its processing history. For this reason, it has been cus-
tomary, both in cold waving and in heat-assisted waving to
select for a particular hair waving operation one of several
ammonium thioglycolate solutions, depending on the nature of
~the hair to be treated. The system of the instant invention
also provides several ammonium thioglycolate solutions of
dif~erent strengths and requires selection ~rom æmong these
.
severa~ solutions of a s~ngle solution suitable for a partic-
ular head of hair.
It iS to be noted, however, that although the sev-
eral soluti~ns used in accordance with the present invention
di~fer substantially from each other in processing strength,
each of them ls weaker than the comparable solutions used on
the same ~ype of hair in cold waving, and each of them is
stronger than the comparable solutions used on the same type
of hair in prior heat-assisted waving systems in which ~pha-
eis was placed on having clamps of maximum specific heat a~
heat content so that the desired elevated temperature could
be maintained as long as possib-e.
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In the instant invention, the clamps are designed
to hold a substantial amount of heat but not so great an
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amount of heat as to retain a high temperature in the clamps beyond the
required processing time. The clamps are limited in mass by the avoidance
of metal inserts or metal particles, or heavy materials of construction
which have been used in prior clamps to maximize heat content. The clamps
used in accordance with this invention are designed to heat wet hair on a
roll to a temperature above 120F. and to maintain it for a period not
longer than six minutes. At temperatures below about 120F. the solutions
used are substantially inactivated with respect to the particular hair for
which they are utilized and the danger of overprocessing is obviated. The
clamps used in this invention and the apparatus for heating them are
described in U. S. Patent No. 3,889,097 dated June 10, 1975. -
In a typical operation, a clamp used in accordance with this
invention is removed from a rod heated to about 220F. and immediately
placed on a curl. The heat retained in the clamp brings the curl up to
processing temperature (about 120F.) in about one to one and one-quarter
minutes. The clamp then continues to raise the temperature of the curl to
a peak temperature of about 125F. and then begins to cool, dropping the
curl temperature to a level below about 120F. within six minutes after
application of the clamp to the curl.
Example 1 ;~
A specific formulation for use in the heat-assisted waving
of normal hair comprises:
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Ammonium thio~lyco~te (60~o aqueous).... 15.100~ parts
~later, deionized............................. 77.3977
Ammonium ~Iyd-roxide......................... 0.2800 "
- Ammonium Bicarbonate........................... 5.4000
Fatty acid modified protein.................Ø5000 "
Perfume.............. ;........................ 0.2000 "
Latex opacifier...... ~........................ 1.0000 "
Dyes.................................... ...... 0.1223 "
The ammonium thioglycolate acts to break disulfide
linkages in the hair. The ammonium hydroxide acts as a swell-
ing a~ent for hair. The a~monium bicarbonate is a buffer.
The ~at~y acid modi~ied protein acts as a carrier for the
perfv~e and also as a penetrating agent for the wetting of
the hair by the lotion.
The above formulation hæs a thioglycolate content
of 9.7~0.1 wt.% (calculated as thioglycolate ion) and a pH
of 7.6~0.1.
Example 2
A specific formulation for use in the heat-assisted
waving of hair ~hich is difficult to process comprises:
Ammonium thioglycolate (60~ aqueous)............... 13.3000 parts
Water, deionized....................................... 78.2890 "
~mmonium hydroxide...................................... 1.2720 "
Ammonium bicarbonate.................................... 5.4000 "
Fatty acid modified protein............................... 0.5000
Perfume.............. ~........................ 0.2000 " -
La~ex opacifier................... ............ 1.0000 "
Dye............................... ............ 0.0395 "
The above formulation has a thioglycolate content
of 8.5~0.1 wt.% (calculated as thioglycolate ion~ and a pH
of 8.4~0.1.
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E~:ample 3
A specific formulation for use in the heat-assisted
waving of tin~ed hair comprises:
~mmoni~n thioglycolate (60~ aqueous)... 4.05 parts
Water, deionized......................... ......... 88.81
Ammonium Hydroxide.. ~......................... ~;............... 1.40 " -
Fatty ~cid modified protein..................... 0.50 "
Perfume......................................... 0.20 "
Enzyme hydrolyzed protein......................... 4.00
Latex opacifier................ .~............... 1.00 "
Dye.................................... ......... 0.04 "
The above formulation has a thioglycolate content
o~ 2.5~0.1 wt.~ (calculated as thioglycol~te ion) and a pH
o~ g.35~0.05.
~xample_4
A speci~ic formulation for use in the heat-assis~ed
waving of bleached hair comprises:
~Jater (deionized)..................... ... 91.522 parts
Methyl p-hydroxybenzoate............... ........ 0.100 "
Propyl p-hydroxybenzoate............... ...... ~ 0.015 "
Ammonium thioglycola~e (60~ aqueous)... 1.200 "
~- - - Ammonillm hydroxide.................... .......... 0.030
Ammonium Bicarbonate................... .......... 5.400
Fatty acid modified protein............ .......... 0.500
Perfume................................ ........ 0.200 "
Latex opaci~ier................ O............... 1.000 "
Dye.................................... ........ 0.033 "
The ab~ve formulation has a thioglycolate content
of 0.75 ~It.%+0.05. It has a pH of 7 . 6~o . 1, or should be ad-
~usted to a pH in this range by the addition of small amountsof ammonium hydroxide, if necessary.
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E.ach of the above formlliationsj as stated abo~e,
drops off substantially in activity (~Jith respec~ to the type
of hair on which it is used) as the clamp loses heat and thus
the danger of overtreating by prolonged exposure is minimi~ed.
Ho~lever, it is nevertheless preferred to remove the clamps
after six to eight minutes of exposure and thereafter imme-
diately ~1ash off excess thioglycolate solution and begin the
oxidation process.
Oxidation of the heated hair to restore disulfide
bonds is carried out in the same manner ae oxidation after
non-heat-assisted thioglycolate treatment. A typical oxidi~-
ing formulation comprises:
Water~ deionized......................... 90.744 parts
Fatty acid quaternary ammonium complex.. 3.oo8
Hydrogen Peroxide (3~% aqueous)................. 6.230
Phosphoric acid to pH 3.5.................. app. 0.009
Silicone antifoam agent....................... O.OlO "
The ~atty acid quaternary ammonium complex is aconditioning agent ~hich serves to improve the combability
of the ~inished waves.
The formulation providPs a hydrogen peroxide con-
tent of 7.3 to 7.5 volume percent and a pH o~ 3.5~0.1 at
80F. ~ -
It is to be understood that the foregoing examples
are ~ntended to be merely illustrative and that modifications
and variations 1~ill be apparent to those skilled in the art.
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