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Description  |
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BACKGROUND OF THE INVENTION
A. Field of Invention
This invention relates broadly to an improved permanent hair waving or
curling process and the composition used therein.
B. Prior Art
Among the components of hair is a proteinaceous material called "keratin".
The hair's keratin is made up of long fibrous polypeptide chains which are
bonded together with horizontal cross bonds of two forms: hydrogen bonds
and cystine bonds, also sometimes referred to as disulfide bonds.
Cystine bonds play an essential role in determining the degree of curl in
hair. Some researches in the field believe that straight or slightly wavy
hair has relatively fewer cystine bonds and relies heavily upon hydrogen
bonding to produce curl or waves in the hair and that very curly hair has
a relatively larger amount of cystine bonds. Other researchers in the
field believe that straight hair and curly hair may have the same number
of cystine bonds, but that the cystine bonds present in straight hair tend
to occur in a relatively straight alignment, whereas the cystine bonds
present in curly hair tend to occur out of alignment. Regardless of which
theory is accepted, while the hydrogen bonds can be broken merely by
wetting the hair, such that straight or slightly wavy hair will lose
virtually all body when wet, very curly hair maintains its body even when
wet because the cystine bonds are relatively unaffected by water. Thus,
very curly hair cannot be easily reset into new or different hair styles
different from its natural state merely by wetting and shaping the hair.
Permanent hair waving is usually carried out by subjecting the hair to a
strong reducing agent, such as hydroxide or, more commonly, materials
containing a free "--SH" group or thiol. These "thiol" materials are also
called mercaptans. In this treatment, the hair is saturated with the thiol
agent, which then acts to break the disulfide bonds.
When a sufficient number of hair disulfide bonds have been broken, the hair
is rinsed, removing the unreacted thiol waving agent and disulfide
reaction product. The hair is then realigned, e.g., usually by winding on
rollers, in order to physically align previously unpaired hair protein
thiol groups, i.e., one-half of the cystine groups. The hair and rollers
are then saturated with an oxidizing agent, or neutralizer, such as
hydrogen peroxide or a bromate salt, to reform disulfide bonds between the
newly paired hair protein thiols and to give the hair a configuration or
wave. This general process may be used to either add curl or straighten
the hair.
Salts of thioglycolic acid, such as ammonium thioglycolate, and
thioglycolic acid esters, such as glycerol mono thioglycolate, are
typically utilized as the thiol waving agent. Other thiol-containing
reagents such as thiolactic acid, beta-mercaptopropionic acid,
beta-mercaptobutyric acid, mercaptosuccinic acid and alike have been
suggested in the art to be effective.
Prior art waving processes are plagued with the problem of either
underwaving or overwaving (under or over processing) that occurs during
waving on different parts of a single hair fiber or different areas of the
hair mass due to the physical or chemical condition of the hair itself.
For example, hair which has been waved, or bleached, or both is more
porous than hair which has not undergone these chemical treatments, e.g.,
these portions of the hair fiber near the hair root which has grown out
since the last bleaching or waving. Similarly, even hair having no
previous history of bleaching or waving is more porous near the tip end
than near the root end simply because hair near the tip has been brushed
more, or has been subjected to more weathering.
As a consequence of these porosity differences, the hair tends to take up
more waving agent in some areas and less waving agent in others. Over
waving or processing tends to occur in the more porous portions of the
hair while underwaving or processing tends to occur in less porous areas.
These trends are exactly the inverse of what is desired since the hair
which usually needs the waving treatment the most gets the least waving,
and visa versa.
Many products today are directed to the special problems and needs of the
Black ethnic market. People in the Black ethnic market have, for example,
hair characterized by a relatively large number of cystine bonds and
relatively high dryness. Conventional permanent waving products have
particular limitations applied to this market. Typically, the products
result in a hair style that is either very curly and quite greasy or
relatively straight and stiff and very dry. These prior products are
characterized by the need for frequent, heavy maintenance, e.g., the
consumer's application of activators and moisturizers on a daily basis or
more than daily basis. None of the prior art compounds are able to produce
a Black ethnic hairstyle characterized by thick, full-bodied hair fibers
which form loose bouncy curls having good moisture retention.
Another problem that occurs during the hair disulfide bond breaking process
is skin irritation caused by the thiol-containing agents. Irritation
occurs usually because beauticians frequently use their bare fingers for
the wrapping process.
U.S. Pat. No. 4,391,286 (Hsiung et al.) and related U.S. Pat. No. 4,572,220
(Hsiung et al.) both disclose hair conditioning formulations that claim to
overcome some of the problems just described. The '286 patent teaches a
composition of water having dissolved therein a quaternary nitrogen
containing polymer and a water-soluble, disulfide-containing
polycarboxylic acid or salt. The '220 patent teaches the same composition
as the '286 patent with the addition of a thiol-containing waving agent.
The preferred disulfide-containing polycarboxylic acids are formed by the
oxidation of two molecules of mercapto-monocarboxylic acid. Examples of
these compounds include dithiodiglycolic acid, three-dithiodipropionic
acid, cystine, dithiodilactic acid, dithiodisuccinic acid and the like.
The preferred quaternary nitrogen containing polymer is a cationic guar
where a chloride anion is usually associated with the polymer. The
cationic guar is distinguished from other forms or derivatives of guar
gum, such as nonionic guar which does not contain quaternary nitrogen
compounds. Both formulations disclosed in these two patents are
specifically designed and recommended for use on the hair after shampooing
and prior to a waving process (i.e., pre-wrap solutions).
Another hair conditioning formulation is disclosed in U.S. Pat. No.
4,588,760 (Jachowicz et al.). This formulation for decreasing hair
hygroscopicity and improving settability comprises an aqueous solution of
heximinium salt and resorcinol. To facilitate application of this
conditioning formulation, it is disclosed that a cosmetically acceptable
thickener, such as guar gum, may be incorporated into the formulation.
All of the known waving processes and solutions associated therewith are
limited in their flexibility to produce a looser, bouncier, curl while
maintaining the moisture of the curls. The present invention provides an
improved in hair waving process, eliminating many of the problems
associated with prior art processes and solutions.
SUMMARY OF THE INVENTION
Thus, an object of the present invention is to provide an improved hair
waving process and further to provide an improved wrapping lotion
composition for use in a hair waving process.
It is an object of this invention to provide a permanent waving process and
wrapping lotion that produces a softer, bouncier curl with an overall
open/looser pattern and that requires less maintenance to maintain the
integrity of the curl.
A further object of the invention is to provide for improvements in
straightness and versatility without dry frizzing of the hair.
A further object is to provide for a reduction in overall processing time,
less irritation, less odor, and a reduction in the danger of
overprocessing.
A still further object is to provide a waving process that imports more
body, sheen and manageability to the hair with improved curl retention.
Accordingly, in a broad embodiment, the present invention is a process of
waving hair by applying to the hair a rearranging composition with
chemical properties sufficient to change the cystine bonds in the hair
keratin to lanthionine bonds. The rearranging composition comprises a
homogenous mixture of a salt of thioglycolic acid and a homopolymer of
methylacrylamidopropyltrimethyl ammonium chloride. After the rearranger
has been left on the hair for a time to accomplish conversion of the
bonds, the hair is rinsed to flush away a substantial portion of the
rearranging composition.
A wrapping lotion composition is then applied to the hair. The wrapping
lotion comprises a homogeneous mixture of a salt of thioglycolic acid and
a guar component. The hair, with wrapping lotion applied is wrapped around
a rod or roller to produce a desired curl pattern. The hair with wrapping
lotion applied is left on the rods for a predetermined length of time,
preferably about 5 to about 15 minutes, in order to set or lock in the
desired curl pattern. The wrapped hair is rinsed to flush away only excess
wrapping lotion composition.
After rinsing, a neutralizer composition is applied to the hair, still on
the rods, to lock in the curl pattern. The neutralizer is left on the hair
for a sufficient period of time to reestablish the cystine bonds, after
which the neutralizer is flushed away by rinsing the hair.
The improved rearranger comprises a salt of thioglycolatic acid and between
about 1.0 and about 3.0% by weight of a cationic homopolymer of
methacrylamidopropyltrimethyl ammonium chloride. In preferred form the
rearranger also includes between about 6.0 and about 10.0% by weight of
ammonium thioglycolate, between about 3.0 and about 7.0% by weight of
monoethanolamine thioglycolate. Also, in preferred form, the rearranger
has a pH of between about 8.0 and about 10.5.
The improved wrapping lotion comprises between about 0.8 and about 2.5% by
weight of a guar component, preferably nonionic guar gum and between about
0.3 and about 7.0% by weight of a salt of thioglycolic acid, preferably
ammonium thioglycolate. In preferred form the wrapping lotion has a pH of
between about 7.0 and about 10.5 and a viscosity of between about 1,800 to
2,200 cps.
These as well as other objects and embodiments will become apparent upon
review of the more detailed description of the invention hereinafter set
forth.
DETAILED DESCRIPTION OF THE INVENTION
The waving process of the instant invention is comprised of several steps,
some of which involve the application of specific hair treatment
formulations. As a first step, a rearranging composition is applied to the
hair to perform a straightening function. The rearranging composition
contains an aqueous solution of chemical agents capable of reducing the
disulfide linkages in hair keratin. Suitable chemical agents include water
soluble mercaptans, e.g. salts of thioglycolic acid, such as, sodium,
monoethanolamine, or ammonium thioglycolate, and magnesium thioglycolate.
Other sources of mercaptans include thioglycerol, sodium or potassium
borohydride, and sodium or ammonium sulfite. The amount of these chemical
agents may vary depending on, among other things, the degree of
straightening desired, hair treatment history, and the chemical nature of
the particular hair to be treated.
A preferred rearranging composition comprises a mixture of ammonium
thioglycolate and monoethanolamine thioglycolate (MEA-Thio). However, it
is within the scope of the invention that either thioglycolate compound
may be used alone or as a substitute for the other. When a mixture of the
two is used the ammonium thioglycolate is preferably present in
concentration ranges of about 6.0 to about 10.0% by weight, and about 3.0
to about 7.0% by weight of the total rearranging composition. The MEA-Thio
is preferably present in concentrations of about a most preferred
rearranging composition comprises about 8.0% by weight of ammonium
thioglycolate and about 5.5% by weight MEA thio. Alternatively, the
rearranging composition may be characterized by the weight ratio of
ammonium thioglycolate to MEA-Thio. A preferred ratio is between about 4:6
and about 7:3 ammonium thioglycolate to MEA-Thio, with a most preferred
ratio of 6:4. When only one salt of the thioglycolic acid is used, the
preferred concentration is between about 5.0 and 20% by weight.
Additionally, a variety of conventional additives may be present in the
rearranging composition, such as, conditioners perfumes, emollients, etc.
The pH of the composition is adjusted to between 8.0 and 10.5, preferably
using ammonium hydroxide.
Surprisingly and unexpectedly it has been found that the addition of a
polyquaternary amine salt to the rearranging composition has a significant
affect on the quality and settability of the hair both during and long
after the waving process. The preferred polyquaternary amine salt is a
highly charge cationic homopolymer of methacrylamidopropyltrimethyl
ammonium chloride (MAPTAC). A preferred concentration of MAPTAC is from
between about 1.0 to about 3.0% by weight of the rearranging composition,
with a most preferred concentration of about 2.0% by weight. The average
molecular weight of the MAPTAC homopolymer ranges from about 100,000 to
about 200,000.
Although not completely understood it is believed that the MAPTAC increases
the longevity of the curl pattern and the humectant qualities of the hair
by penetrating into the pore of the hair. When the neutralizer solution is
applied the polymer is believed to become "locked" into the hair. The
increased integrity of the hair and the curl pattern that results from the
application of MAPTAC greatly reduces the need for maintenance between
subsequent waving treatments.
Additionally, a variety of conventional additives may be present in the
rearranging composition, such as, conditioners, perfumes, moisturizers,
emollients, etc. The pH of the composition is adjusted to between 8.0 and
10.5 using, preferably, ammonium hydroxide.
The rearranging composition is initially applied to the head and worked
into the hair with gentle massage. The rearranging composition is allowed
to stand, on the hair for about 5-15 or 20 minutes while the cystine bonds
are being broken down to lanthonine bonds, the length of time the
rearranger is allowed to stand depends upon the degree of curl in the
hair's natural state and the degree of straightness desired.
After the hair has straightened to the desired degree, the hair is rinsed,
preferably with warm water for about 3-5 minutes to flush away the major
portion, preferably all, of the rearranging composition. In this way, the
rearranging composition and the wrapping lotion composition are not
applied to the hair at the same time.
After the hair has been rinsed, a wrapping lotion is applied to the head
and gently massaged into the hair. The hair is then wrapped on rods,
curlers, rollers or any other means known to the art to produce or
establish a desired curl pattern. The wrapped hair containing the wrapping
lotion is allowed to stand for a period of about 5-15 minutes, while the
pattern of the curl becomes set.
The wrapping lotion of the invention is a homogeneous mixture including a
salt of thioglycolic acid and a guar component. The wrapping lotion is
specifically formulated to reduce the possiblity of oxidation of the hair
that may occur due to air exposure. Thus, the wrapping lotion includes a
reducing compound, as does the rearranger, but the reducing compound in
the wrapping lotion is present in lower concentrations then in the
rearranger. Oxidation is undesirable because it has the tendency to
reverse the relaxing process which resulted from contact with the
rearranging composition, and, thus, reform the cystine bonds prematurely.
The preferred salt of thioglycolic acid used in the wrapping lotion is
ammonium thioglycolate. A preferred concentration range of the ammonium
thioglycolate is between about 0.3 and 7.0% by weight of the total
wrapping lotion composition, with a most preferred concentration of about
2% by weight. It is also within the scope of the invention that the
wrapping lotion does not contain any appreciable amount of salt of
thioglycolic acid, although some level of reducing agent is preferable as
noted.
The guar component of the wrapping lotion is obtained from guar gum, also
known as guar flower. Guar gum is a commercially available water soluble
plant mucilage consisting of linear chains of galactose and manose
molecules. A preferred source of guar is nonionic guar, most preferably a
highly substituted hydroxypropylated guar gum.
Guar gum is a recognized thickening agent in systems that were not
chemically active. However, it has now been discovered that guar gum can
be used in a chemically active system, i.e., a system containing
substantial amounts of active thioglycolates. Moreover, it has been
discovered that the presence of the guar component in this wrapping
solution significantly increases the volume and body of the hair as a
result of the waving process. The curl pattern that results from the
waving process is an overall more open/looser and bouncier pattern than
was previously possible with prior art waving processes. Although the
mechanism of the invention is not completely understood, it is believed
that the use of a guar component in the wrapping lotion composition is
directly attributable to producing the desired softer, bouncier more
versatile curls. The guar component penetrates the hair where it is
believed that the guar influences the reformation of the cystine bonds in
the hair, so that when the neutralizer is applied the desired curl pattern
is achieved. These advantages of using guar gum were unforeseen. A
preferred concentration of the guar component in the wrapping lotion is
from about 0.2 to about 2.5% by weight of the total composition, with a
most preferred concentration of about 0.8% by weight.
In addition to the above components, the wrapping lotion composition may
also contain other ingredients well known to the art, such as, emollients,
conditioners, perfume, surfactants, moisturizers, etc. The wrapping lotion
composition may be prepared by any suitable procedure known to the art. A
preferred procedure involves first dissolving the guar component into
water that is at or below ambient temperature. The water-guar solution is
then heated to about 70.degree.. Any additional ingredients are then added
and the resulting mixture is cooled to about 50.degree. F. Lastly, the
salt of thioglycolic acid is added, if any, with an amount of ammonium
hydroxide to adjust the pH of the final wrapping lotion composition to
between about 7.0 to about 10.5, most preferably 9.0 to about 9.6. The
resultant wrapping lotion composition has a gel consistency, with a
viscosity range from about 500 cps to about 12,000 cps, most preferably
from about 1,800 to about 2,200 cps.
After the wrapping lotion has been allowed to stand on the wrapped hair for
a period of about 5 to about 15 minutes, the wrapped hair is then rinsed
with warm water to remove any excess wrapping lotion composition.
After rinsing, a neutralizer is applied to the wrapped hair to restore the
disulfide linkages in the hair keratin. The neutralizer "locks in" the
curl pattern that was formed in the previous steps of the waving process.
The exact composition of the neutralizer is not believed critical to
achieve the improved results obtained by the waving process of the
invention. As known to the art, neutralizers are typically aqueous
solutions containing oxidizing agents, such as, sodium bromate. Other
ingredients may be added to the neutralizer composition to improve the
aesthetic properties of the hair. In particular, it has been found that
the addition of from about 1.0 to about 5.0% by weight of ethoxylated
castor oil greatly improves the sheen quality of the hair.
After application of the neutralizer, the wrapped hair is then rinsed with
warm water to remove a substantial portion, preferably all, of the
neutralizer composition. The rods are then removed and the hair is again
rinsed with water. As an optional post-treatment step a sealer may be
applied to the hair to elevate the initial dryness that sometimes results
immediately after the hair has undergone a waving process. Well known to
the art, sealers contain conditioners and humectants.
In order to more fully demonstrate the attendant advantages arising from
the present invention, the following examples are set forth. It is to be
understood that the following is by way of example of only and is not
intended as an undue limitation on the otherwise broad scope of the
invention.
EXAMPLE I
A waving process in accordance with the invention was performed using both
an improved rearranging composition and an improved wrapping lotion. The
first step in the process involved pre-shampooing the head with a suitable
conditioning shampoo. The hair was then towel blotted dry. The improved
rearranging composition was then applied to the hair by a tint-brush
procedure in an effect to minimize scalp irritation. The rearranger used
comprised a homogenous mixture of a homopolymer of MAPTAC and MEA
thioglycolate. Table I lists the relative weight fractions of the
rearranger components. The rearranger was allowed to stand on the hair for
about 10 to 15 minutes until straight.
After the processing with the rearranger was completed the hair was rinsed
thoroughly for about 3 to 5 minutes with warm water, then towel blotted
dry. The improved wrapping lotion composition of the invention was then
applied in 1/4 head sections. The wrapping lotion comprised a homogenous
mixture of ammonium thioglycolate and nonionic guar. Table II lists the
relative weight fractions of the components for the improved rearranger.
The hair in each 1/4 section was then wrapped on rods to produce a curl
pattern. After rodding, the wrapping lotion was allowed to stand on the
hair for about 10 minutes.
The hair with the rods intact was then rinsed thoroughly with warm water
and then towel blotted dry.
A conventional neutralizer solution having sodium bromate as the active
ingredient was then applied sparingly to each rodded portion of hair and
allowed to stand for about 10 minutes under a plastic wrap. After
processing with the neutralizer, the rodded hair was then rinsed well with
warm water for about 3 to 5 minutes to substantially remove the
neutralizer. The hair was then unrodded, rinsed again, and dried under a
conventional hair dryer.
The resultant hair style obtained from the waving process of the instant
invention was characterized as having a looser, bouncier, more open
pattern of curls than hair styles previously possible using prior art
waving process. The hair resulting from the Example I was characterized as
having thicker, more full bodied hair than results from prior art waving
processes. In addition, the longevity of the curl pattern produced and the
humectant quality of the hair was increased on a relatively long term
basis with substantially lower need for application of maintenance
products. The softer, bouncier curls obtained as a result of the instant
process is believed directly attributable to the use of the improved
wrapping lotion composition, containing the guar component.
EXAMPLE II
For the purposes of comparison to the improved waving process of the
invention as described in Example I, a conventional prior art waving
process was performed. The procedure use for the conventional waving
process was identical to that of the waving process of Example I with the
exception that the wrapping lotion used did not contain a guar component,
and the rearranger did not contain a homopolymer of MAPTAC. Also, ammonium
thioglycolate was substituted for MEA thioglycolate. The wrapping lotion
and rearranger formulations detailed in Tables I and II.
The resultant hair style obtained from the conventional waving process was
characterized as relatively tightly curled, dry, and frizzy in appearance.
Furthermore, this style required the application of maintenance products,
such as, moisturizers and curl activators. These maintenance products
cause an overall greasy look of the hair style.
TABLE I
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Deionized H.sub.2 O
59.7 59.6
MAPTAC 2.0 --
Ammonium Thioglycolate
8.0 10.0
MEA Thioglycolate 5.5 --
Other Ingredients.sup.1
24.8 30.4
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.sup.1 Conditioners, surfactants, pH adjusters, moisturizers and
fragrance.
TABLE II
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Example I
Example II
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Deionized H.sub.2 O
92.6 92.6
Ammonium 2.0 2.0
Thioglycolate
(60% solution)
Nonionic Guar 0.75 --
Other ingredients
balance balance
pH 9.1-9.3 9.1-9.3
Viscosity, cps 1,800-2,200
1,200-1,600
Appearance gel/lotion
lotion
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The foregoing examples and specification disclose preferred and generalized
illustrations of the invention. However, variations are possible within
the scope of the invention. For example, the wave wrapping lotion of this
invention is believed to provide advantages when used with any rearranger
or neutralizer. It should be understood, therefore, that the invention is
to be limited only by the following claims and their equivalents.
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