Note: Descriptions are shown in the official language in which they were submitted.
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COMPOSITIONS AND METHODS FOR REMOVING THE COLOR FROM
PERMANENTLY DYED KERATIN FIBERS
FIELD OF INVENTION
The present invention relates to the removal of color from dyed keratin
fibers, such
as human hair or wool, with compositions containing bicarbonate salts and
hydrogen
peroxide. The present invention is capable of providing a degree of lift in
previously dyed
keratin fibers which, heretofore, has not been possible under mild reaction
conditions.
Further, the invention described herein is especially suitable for use on
keratin fibers
l0 which were chemically treated prior to subsequent dyeing.
BACKGROUND OF THE INVENTION
The use of dyes to change the color of keratin fibers has been known for
centuries.
Natural dyes from animal and plant sources were first used to dye keratin
fibers. Later,
synthetic dyes largely replaced natural dyes because synthetic dyes provided a
more
consistent and predictable coloring of the keratin fiber. One example of the
use synthetic
dyes is the coloring of human hair, wool, and furs with oxidative dyes.
Use of oxidative dyes to change the color of keratin fibers involves the use
of
hydrogen peroxide or an agent capable of producing hydrogen peroxide in
solution, and
small compounds, called dye intermediates. The hydrogen peroxide is admixed
with the
dye intermediates just prior to application to the keratin fiber. Hydrogen
peroxide causes
the small dye intermediates to couple inside the keratin fiber forming a large
colored
molecule. This colored molecule imparts color to the keratin fiber and is of
sufficient size
that it cannot diffuse out of the fiber without further chemical treatment. A
single oxidative
dye treatment lasts from 10 to 30 minutes with the more customary treatments
ranging in
length from 20 min to 30 min. While fairly straight forward, this process is
not without
consequence. The oxidizing agent, in this example hydrogen peroxide, can also
weaken
the keratin fiber by attacking the proteins which give the hair it's
structural integrity. In
fact, a number of factors combine to determine whether or not the dyed fibers
will be
3o excessively damaged. These include the concentration of the oxidizing
agent, the duration
of the treatment, and most importantly the initial condition of the fiber.
Those skilled in
the art know that keratin fibers which have already been weakened by prior
chemical or
mechanical treatments, can be severely damaged, sometimes to the point of
breakage, by
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treatment with oxidizing agents.
Human hair will be used as an example of such keratin fiber for demonstration
purposes. The importance of hair to the human psyche is evident by the
multitude of
different methods available for changing its appearance. Through the ages
different
methods of coloring, straightening, curling, and otherwise changing the
appearance of the
hair have been developed. While bleaching and coloring of hair are among the
most
widely practiced modifications to human hair today, other treatments are also
used to
obtain the desired "look". Curly hair is physically or chemically
straightened, and straight
hair can be physically or chemically curled. Each of these treatments causes
some
weakening of the proteins which give hair its structural integrity and great
care must be
taken to minimize excessive damage to the fiber.
Sometimes, fibers dyed with an oxidative dye are found to have an undesirable
coloration, a condition which could be remedied by removal of the dye
molecules.
Current compositions containing hydrogen peroxide alone, or in combination
with
1 s penetration enhancers like ammonia, fail to remove dye molecules from
keratin fibers.
However, the present art does describe the use of "boosters" which, when added
to a
bleaching composition containing hydrogen peroxide, remove dye molecules from
keratin
fibers. The boosters of current art are typically salts of peroxy acids.
Although
percarbonates and perborates have been suggested as boosters for lifting hair,
the most
commonly employed boosters are persulfate salts. Several persulfate salts are
currently
employed in dye removal compositions to provide a degree of lift in dyed hair
in excess of
that obtained when hydrogen peroxide and ammonia are used alone. These include
ammonium persulfate, potassium persulfate, and sodium persulfate. Typically,
these salts
or blends of these salts are packaged separately from the hydrogen peroxide.
In use, a
packet of persulfate is added to the hydrogen peroxide immediately before the
mixture is
applied to the hair. Unfortunately, those skilled in the art also know that
persulfates are
among the most damaging oxidative agents which can be applied to the hair. The
use of
persulfate boosters to remove dye molecules from hair weakens the fiber
because of
uncontrolled side reactions with the proteins which give the fiber its
structural integrity.
3o Persulfates can be especially damaging to hair which has received a
permanent wave or
has been chemically straightened. Persulfate boosters also present many
problems for the
product manufacturer and the consumer as well.
Persulfates are very reactive oxidizing agents. This reactivity causes
problems in
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the storage, handling and shipping of these materials. Manufacturers of hair
color
products often must rely on contract packagers for the preparation of booster
packets.
Those manufacturers who chose to prepare booster packets must invest a great
deal of
time, energy, and equipment in ensuring the safe handling and shipping of
these materials.
s The end result of this effort is an increased cost of manufacturing for
color-removal
products which require a persulfate booster.
The separate packaging made necessary by the reactivity of persulfate boosters
also
raises safety concerns for consumers. Persulfate boosters tend to be
irritating and even
toxic if ingested. The small packets of persulfate booster employed in the
current art could
easily be opened and ingested by children. Further, the opening of booster
packets can
cause the powdered persulfates to become airborne. Particles of persulfate
boosters which
come into contact with the eyes, skin, and mucous membranes can easily cause
burns or
inhalation-related illnesses.
The use of persulfate boosters presents further problems in actual use. The
~ s boosters of the current art are somewhat difficult to dissolve. The
mixture of hydrogen
peroxide and these persulfate boosters must be shaken until the persulfates
are fully
dissolved. Thus the difficulty in dissolving persulfates causes excessive
foaming of the
product and builds up pressure inside the mixing vessel. Therefore, the
violent,
involuntary evolution of product from the container represents a possible
health hazard to
2o the user. Further, persulfate boosters often enhance the "chemical" odor of
the finished
blend making the color-removal treatment less pleasant for the consumer.
Surprisingly, the inventors have discovered that a degree of dye removal
comparable to and in some instances superior to that obtained with a
persulfate
booster/peroxide combinations can be obtained under relatively mild conditions
using
25 bicarbonate salts and hydrogen peroxide. Further, the inventors have
discovered that the
bicarbonate ion plays a major role in the decolorization of oxidative dye
molecules in
keratin fibers. Carbonate salts which are not comprised of a blend of
bicarbonate and
carbonate forms, do not provide the same degree of decolorization as is
obtained with
bicarbonates having the same canon. In those cases where the carbonate salts
of
3o commerce are comprised of mixtures of the carbonate and bicarbonate forms,
such as
ammonium carbonate, the degree of decolorization provided by the use of said
salt is
proportional to the amount of the bicarbonate form present in the mixture.
This previously
unknown and unsuspected attribute of bicarbonate ion provides for a relatively
safe,
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natural, non-toxic booster for the removal of dye molecules from keratin
fibers. The
present invention pro~~ides for the removal of dye molecules from keratin
fibers under
reaction conditions milder than those in which persulfates are used and is
especially
suitable for use on keratin fibers which have been weakened by prior chemical
treatments.
DETAILED DESCRIPTION OF THE INVENTION
The method and compositions of this invention provide a means of removing dyes
from keratin fibers under relatively mild conditions. This dye removal is
accomplished
through the use of bleaching compositions containing hydrogen peroxide and
bicarbonate
1o salts. The present invention is especially useful to people who have dyed
their hair and
wish to return their hair to its original color or for people who wish to have
variegated hair
coloring.
The coloring of keratin fibers is normally achieved by the use of chemical
dyes.
There are many different types of dyes used to color keratin fibers. These
dyes include, but
are not limited to, semi-permanent dyes, direct dyes, oxidative dyes, and
reactive dyes.
Oxidative dyes are commonly used when permanently coloring human hair. For the
purposes of this invention, human hair can be taken as representative of the
class of fibers
known as keratin fibers. The use of human hair as an example should not limit
the scope
of applications for the present invention as it is commonly known that animal
fibers, such
2o as wool and furs, are considered keratin fibers.
The coloring of hair with oxidative dyes in its simplest form is achieved by a
process wherein small compounds known as dye intermediates are caused to react
with
one another in a process called coupling. This coupling reaction requires
initiation my an
oxidizing agent such as hydrogen peroxide. When coupling reactions between dye
intermediates occurs inside the keratin fiber, a large, colored molecule is
formed inside the
fiber. The sheer size of this molecule prevents it from being removed from the
hair by any
process other than chemical reaction. The color imparted to the fiber is then
a result of a
chemical process initiated by an oxidizing agent such as hydrogen peroxide.
Those skilled
in the art will recognize that current ammonium hydroxide/hydrogen peroxide
bleaching
3o solutions are ineffective for removing dye molecules from keratin fibers.
Those skilled in
the art will likewise know that, while persulfate boosters do permit removal
of dye
molecules from hair fibers, these treatments are extremely damaging to the
hair fibers.
Therefore, the bleaching solutions of the current art do not permit
individuals with
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chemically treated hair who have also dyed their hair to safely return their
hair to its
original color.
Surprisingly, the inventors have discovered that the use of bicarbonate salts
in
conjunction with oxidizing agents, such as hydrogen peroxide, will remove
oxidative dye
molecules not only from the surface of the dyed keratin fibers, but will also
remove dye
molecules deposited within the cortex of the fiber. Additionally, the higher
the
concentration of bicarbonate ions present in the bleaching composition, the
faster the rate
and the greater the degree of dye removal from the hair.
Preferably, compositions useful in the present invention contain a bicarbonate
salt
1o or blend of bicarbonate salts yielding a bicarbonate concentration from
about 2.0 x 10'
mole percent to about 4.0 x 10-' mole percent of the final bleaching mixture.
For the
purposes of accuracy it is necessary to express the bicarbonate concentrations
here as mole
percent. Mole percent represents the number of moles of bicarbonate anion per
100 g of
finished formulation. When formulating a product, these mole percent values
can be
converted to weight percent by simply multiplying the given mole percent by
the
molecular weight of the pure bicarbonate salt. The actual weight percent of
the individual
bicarbonate salts used in any given bleaching composition is dependent on the
molecular
weight of the cation associated with the bicarbonate ion in said salt. For
example, sodium
bicarbonate has a molecular weight of 84.01. Of that total the molecular
weight of the
2o sodium cation is 22.99 and bicarbonate is 61.02. Guanidine bicarbonate has
a molecular
weight of 120.09 of which the guanidine cation comprises 59.07 and the
bicarbonate anion
is 61.02. To achieve the same amount of bicarbonate anion (0.09 mole percent
for
example) in bleaching solutions containing these two materials it would be
necessary to
add 10.8 wt% guanidine bicarbonate but only 7.6 wt% sodium bicarbonate.
Therefore for
clarity the bicarbonate ranges given in this description are expressed as mole
percent.
More preferably the bicarbonate salt or salts of said invention should be
present in an
amount ranging from about 9.0 x 10-Z mole percent to about 2.5 x 10-' mole
percent of the
final mixture. For the purposes of the present invention, the term bicarbonate
salt is any
agent or combination of agents capable of generating bicarbonate anion in
solution.
Additionally, compositions useful in the present invention preferably contain
an
amount of hydrogen peroxide, or peroxygen compound capable of generating
hydrogen
peroxide in solution, sufficient to yield an active oxygen content of from
about 0.1 wt% to
about 10.0 wt% and more preferably from about 2.5 wt% to about 7.0 wt%. For
the
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purposes of the present invention, active oxygen is defined as the
concentration of oxidant
which can be readily determined by the standard assay procedures set forth by
the
Cosmetic, Toiletry, and Fragrance Association, Inc. (CTFA) Methods E29-l and
E30-1
issued in October, 1994. Further, the hydrogen peroxide component of the
present
invention may also contain stabilizers, thickeners, and such ingredients
which, when added
to the peroxide solution, impart aesthetic properties without destabilizing
hydrogen
peroxide.
Preferably, the pH of the compositions of the present invention should be
maintained in the range where bicarbonate is the predominant species over
carbonate or
1o carbon dioxide. This range is accepted to be the pH range of from about 7.0
to about i0.5.
More preferably, a pH within the range of from about 7.5 to about 9.5 should
be
maintained.
Additionally, the compositions of the present invention may contain various
penetration enhancing agents. Examples of common penetration enhancing agents
include
but are not limited to urea and ammonia. However, the benefit of certain
penetration
aides may be limited by their ability to convert the highly desirable
bicarbonate to its
ineffective carbonate form or to carbon dioxide. For example, ammonium
hydroxide is
routinely added to bleaching compositions of the current art to enhance the
action of
peroxide on natural melanin pigments. In the present invention, however, the
hydroxide
ion of ammonium hydroxide readily converts the necessary bicarbonates to their
ineffective carbonate form. Therefore, care should be exercised when using
penetration
enhancers so that an excess of bicarbonate anion is always present in the
finished
composition. Other ingredients such as stabilizers for inhibiting the
decomposition of
peroxide, thickening agents and other ingredients which, when added, provide
aesthetic
qualities to the composition or to the treated hair may also be incorporated
into the present
invention provided that these materials do not convert the bicarbonate salts
to their
carbonate form or to carbon dioxide. Examples of such ingredients include, but
are not
limited to, conditioning agents, gelling agents, and moisture retention aides.
In general, any soluble bicarbonate salt may be used in the present invention
3o including, but not limited to, sodium bicarbonate, guanidine bicarbonate,
ammonium
bicarbonate, lithium bicarbonate, and potassium bicarbonate. Preferably, salts
of known
bicarbonate content are used in the compositions of the present invention. But
the method
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of combining carbonate salts with an acidic material can be used to generate
bicarbonate in
situ with the same end result.
As indicated previously, the degree of dye removal and the rate of the
bleaching
reaction increase as the concentration of bicarbonate ions in the bleaching
composition is
s increased. Preferably, the bicarbonate salt comprises from about 0.1 to
about 30 wt% of
the bleaching composition. More preferably, the composition contains from
about 2.0 to
about 20 wt% of the bicarbonate salt. Additionally, the composition preferably
contains
from about 0.5 to about 30 wt% of a peroxygen compound (capable of giving an
active
oxygen titer of from 0.1 wt% to about 10.0 wt% using the CTFA Methods
described
to above). More preferably, the bleaching composition contains from about 8.0
to about 20
wt% of the peroxygen compound. However, the weight percents for the
bicarbonates are
just general ranges and are dependent on the type of bicarbonate salt used. As
stated
earlier, the actual weight percent will depend on the amount of a particular
bicarbonate
needed to achieve the desired mole percents discussed above. Also, the actual
amounts
15 used will depend on the color of the dyed hair and the degree of dye
removal desired.
Additionally, the present invention may be used to enable an individual to
obtain
variegated hair colors. Currently, a person who wants variegated hair must
section the hair
and apply a different coloring or bleaching solution to each section of the
hair. This
process is very time-consuming, expensive, and until now not subject to being
reversed if
2o dyes were used to impart multiple hues to the hair. However, using the
compositions of
the present invention, an individual would be able to initially dye their hair
one color, and
then selectively add a bicarbonate/peroxygen composition to different parts of
their hair to
remove the dye from those parts, thereby creating variegated hair in a process
involving
fewer steps than the processes currently used by hair-care professionals.
25 This process for obtaining variegated hair is especially useful for
individuals who
have chemically treated their hair before coloring it. When an individual
chemically treats
their hair, such as relaxing or straightening it, the chemicals used tend to
dull the hair.
Conversely, hair dyes tend to add sheen to the hair, thereby countering the
dulling effect.
The present invention allows an individual with curly hair to consecutively
relax their hair,
30 obtain a variegated hair color using dyes and the compositions of the
present invention,
and retain the added sheen imparted to the hair by the dye treatment.
To remove dyes from other keratin fibers, such as wool and furs, the processes
are
generally the same as for the removal of dye from human hair. A
bicarbonate/peroxygen
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composition is supplied and either applied to only a portion of the fibers, to
remove small
areas of color, or to all of the fibers, to remove all of the dyed color. The
present
invention, therefore, has a wide utility in a variety of different areas, such
as the
production of keratin based textiles.
This invention is further illustrated by the following examples, which are not
to be
construed in any way as imposing limitations upon the scope thereof. On the
contrary, it is
to be clearly understood that resort may be had to various other embodiments,
modifications, and equivalents thereof, which, after reading the description
herein, may
suggest themselves to those skilled in the art without departing from the
spirit of the
to present invention.
EXAMPLES
Examples 1-12
For Examples 1-12, blonde hair obtained from DeMeo Brothers, Inc. (New York,
New York) was used as the substrate. Several tresses of this hair were dyed
with each of
a number of different shades of oxidative dyes manufactured by Carson Products
Company (Savannah, Georgia). These dyes are representative of the oxidative
dyes
formulations currently available in the cosmetics market. Table 1 sets forth
the Sample
number for each tress of hair, the dye that was used to treat the tress, and
the visual
2o observations for each sample as recorded approximately two days after the
hair was dyed.
TABLE 1
Dye Products Used to Prepare Tresses for Evaluation of Bleaching
Compositions
Example Product Observations on Initial Color
Example #371 Jet Black Tress is uniformly dyed a dark
1 black color
Example #372 Natural BlackTress is uniformly dyed a black
2 color
Example #373 Brown Sable Tress is uniformly dyed a dark
3 brown
(almost black) color
Example #374 Rich Auburn Tress is uniformly dyed a medium
4 red-
brown color
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Example #375 Sunset AuburnTress is uniformly dyed a dark
red-brown
color
Example #376 Autumn Red Tress is uniformly dyed a pinkish-red
6 color
Example #377 Light Brown Tress is uniformly dyed a very,
7 very light-
milk chocolate color. Very little
dye
deposition
Example #381 Spicy CinnamonTress is uniformly dyed a light
8 orange-pink
color
Example #382 Midnight BlueTress is uniformly dyed a dark
9 blue black
color
Example #383 Black Ruby Tress is uniformly dyed a dark
black color
with slight maroon highlights
Example #385 Deep Copper Tress is uniformly dyed a deep
11 orange-red
color
Example #386 Mocha Brown Tress is uniformly dyed a medium
12 heather-
brown color
Next, a simple aqueous bicarbonate/peroxygen solution was prepared. This
solution contained 1 S.0 wt% ammonium bicarbonate and 10.9 wt% hydrogen
peroxide (35
active). Individual tresses of dyed hair were attached to the inside wall of a
250 ml
5 beaker so that only the lower half (or approximately the lower half) of each
tress was
exposed to the bicarbonate/peroxygen solution. After 30 minutes, the tresses
were
removed from the beaker, rinsed and dried, and a visual observation was
recorded for each
sample. These observations are set forth in Table 2. It should also be noted
that the
temperature of the solution in the beaker rose significantly, from about 1 S-
20° C to about
10 35-40° C during these tests. This temperature rise signals that the
destruction of dye
molecules by bicarbonate/peroxygen is an exothermic process. No attempt was
made to
control the temperature of the process during this experiment.
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TABLE 2
Observations for Dyed Hair Treated with Bleaching Compositions Containing
Ammonium Bicarbonate and Hydrogen Peroxide
Example Product Observations on Post-Bleach Color
Example #371 Jet Black Upper portion of tress remains
1 a dark black
color. Lower portion of tress
is dark brown
Example #372 Natural BlackUpper portion of tress remains
2 a black color.
Lower portion of tress is light-to-medium
brown
Example #373 Brown Sable Upper portion of tress remains
3 a dark brown
(almost black) color. Lower portion
of tress
is very light brown (almost yellow)
Example #374 Rich Auburn Upper portion of tress remains
4 a medium
red-brown color. Lower portion
of tress is a
yellow-gold
Example #375 Sunset AuburnUpper portion of tress remains
a dark red-
brown color. Lower portion of
tress is a
yellow-to-light orange color
Example #376 Autumn Red Entire tress is now a light gold
6 color
Example #377 Light Brown Entire tress is now a white-blonde
7 color. No
dye color is present
Example #381 Spicy CinnamonTress is now a yellow color with
8 traces of
pink near the upper end of the
tress
Example #382 Midnight BlueUpper portion of tress remains
9 a dark blue
black color. Lower portion is
light brown
Example #383 Black Ruby Upper portion of tress remains
a dark black
color with slight maroon highlights.
Lower
portion of tress is now light
brown with
slight auburn highlights
Example #385 Deep Copper Tress is now a light yellow color
11 with some
slight light-orange tint near
upper end of
tress
to
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Example 12 #386 Mocha Brown Upper portion of tress remains a medium
heather-brown color. Lower portion of tress
is yellow
To compare the bicarbonate/peroxygen solution's effectiveness against that of
a
known combination of bleaching agents, ammonium hydroxide/peroxygen, a second
tress
of each dyed sample given in Table 1 was exposed to an aqueous solution
containing 4.75
wt% ammonium hydroxide (28% active) and 10.9 wt% hydrogen peroxide (35 %
active).
As in the earlier experiment, each of the tresses was attached to the inside
wall of a 250 ml
beaker so that the lower half of each tress was located within the ammonium
hydroxide/peroxide solution. After 30 minutes, the tresses were removed from
the beaker,
rinsed and dried, and a visual observation was recorded for each samples.
These
observations are set forth in Table 3.
TABLE 3
Observations for Dyed Hair Treated with Bleaching Compositions Containing
Ammonium Hydroxide and Hydrogen Peroxide
Example Product Observations on Post-Bleach Color
Example #371 Jet Black No visible change in color of
1 tress
Example #372 Natural BlackNo visible change in color of
2 tress
Example #373 Brown Sable No visible change in color of
3 tress
Example #374 Rich Auburn Upper portion of tress remains
4 a medium
red-brown color. Extreme lower
portion of
tress has faded slightly but
remains a
medium red-brown color
Example #375 Sunset AuburnUpper portion of tress remains
5 a dark red-
brown color. Extreme lower portion
of tress
has faded slightly but remains
a dark red-
brown color
Example #376 Autumn Red Extreme lower portion of tress
6 has faded to a
pinkish color
Example #377 Light Brown No visible change in color of
7 tress
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Example #381 Spicy CinnamonExtreme lower portion of tress
8 has faded to a
pinkish color
Example #382 Midnight No visible change in color of
9 Blue tress
Example #383 Black Ruby No visible change in color of
tress
Example #385 Deep Copper Extreme lower portion of tress
11 has faded to a
pink-orange color
Example #386 Mocha Brown Extreme lower portion of tress
12 has faded to a
lighter shade of heather-brown
color
As can be seen by the results, the bicarbonate/peroxygen solutions removed a
substantial amount of the dye from each sample and lightened each tress
considerably.
Conversely, the known bleaching combination of ammonium hydroxide/peroxide
failed to
5 remove any color from the darker shades of dye and only slightly, if at all,
lightened the
color of tresses treated with lighter shades of dye. The slight activity
against lighter
shades of dye can be explained by the poor deposition of color obtained
initially with these
dyes. Poor deposition during dyeing means that the majority of the color
imparted to the
tress is deposited on the surface of the fiber only. Whereas, normally the
color would be
i0 deposited deep inside the fiber. Surface deposits of color can also be
readily removed by
the simple act of shampooing. Therefore, the blend of ammonium
hydroxide/peroxygen
was no more effective than shampooing in this experiment.
Examples of bicarbonate salts which can be employed in this manner include but
are not limited to sodium bicarbonate, potassium bicarbonate, and guanidine
bicarbonate.
When ammonium bicarbonate and guanidine bicarbonate are the salts of choice,
effective
color removal from the dyed hair is achieved at concentrations of bicarbonate
lower than
those of potassium and sodium bicarbonates. It is, however, preferred that the
total
bicarbonate content of the bleaching composition remain within the range of
the mole
percents previously determined to provide the desired color removal.
Example 13
In Example 13, bicarbonates were added to a commercial hair-bleaching product
using a packet of dry, powdered bicarbonate salt or a mixture of bicarbonate
salts. This
approach was chosen to illustrate the ability of bicarbonate salts to impart
dye removal
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properties to commercial bleaching products and to show the effectiveness of
systems
more complex than simple aqueous solutions. As can be seen from the following
discussion, the addition of bicarbonates to commercial hair bleaching
compositions, which
are normally effective only against natural hair pigments, converts these
formulations to
highly effective dye removers.
Bicarbonate salts were used to replace the High-Lift Booster (Part C) of a
commercially-available, hair-bleaching product having the following
composition:
Park A - Developer (approximately 80 ml)
to Water, hydrogen peroxide, polyquaternium-37, mineral oil, PPG-1 trideceth-
6,
pentasodium pentetate, and phosphoric acid.
Part B - Color Base (approximately 48 ml)
Water, dihydroxyethyl soyamine dioleate, isopropyl alcohol, ethanolamine,
oleic
acid, propylene glycol, PEG-3 cocamine, sodium dihydroxyethylglyoine,
trisodium
HEDTA, sodium sulfite, sodium erythorbate, TEA-cocoyl hydrolyzed collagen,
potassium
cocoyl hydrolyzed collagen, p-phenylenediamine, 4-chlororesorcinol, m-
aminophenol, and
4-vitro-o-phenylenediamine sulfate.
2o Part C - High-Lift Booster
Ammonium persulfate, potassium persulfate, sodium metasilicate, sodium
persulfate, sodium stearate, hydrated silica, hydroxypropyl methylcellulose,
EDTA,
aluminum distearate, sodium lauryl sulfate, and silica.
The instructions for product use required that the Booster of Part C be
dissolved in
the Developer of Part A. The Color Base of Part B is then added to the blend
of booster
and developer and shaken well prior to application to the hair. This same
procedure was
followed in experiments replacing the High-Lift Booster with bicarbonates. In
all tests, the
finished mixture was applied to tresses of dyed hair for a total of treatment
time of 30
min. Samples of the product prepared according to manufacturers directions
were
3o evaluated as controls in this experiment.
Tresses of hair dyed a dark-black color (See Table 1 of Example 1 ) were
exposed
to the product prepared according to the manufacturers instructions (with high-
lift
booster) and to samples of the product in which the Booster had been replaced
with 16.0
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WO 99/60993 PCTNS99/11741
grams of sodium bicarbonate. The treated tresses showed that noticeably more
of the dyed
color was removed from the tresses treated with the formulation containing
bicarbonate
than those treated with the product containing the persulfate booster. In
fact, the product
containing the High-Lift Booster had very little effect on the color of the
dyed hair.
Though not directly related to the outcome of the experiment, it was also
noted that the use
of bicarbonate overcame several other disadvantages of the current product.
First, the
persulfate booster could only be dissolved in the developer with undesirable,
vigorous and
extended shaking. Because of the shaking necessary to dissolve the booster,
the product
foamed profusely. This foaming interfered with the addition of the color base
to the
to developer. Further, the conditioning agent in the developer precipitated
when the
persulfate booster was added. The mixture containing the persulfate booster
also
developed a strong irritating odor. The sample containing sodium bicarbonate
did not
suffer from any of these problems.
This example demonstrates that bicarbonates can be added to an existing hair
bleach composition containing hydrogen peroxide and ammonia in a manner
similar to
that currently employed with persulfate boosters. However, when using this
approach, the
bicarbonate salts should be added in an amount sufficient to ensure that all
of the
bicarbonate is not converted to its carbonate form by the hydroxide present in
the product.
The presence of residual bicarbonate anion in the final mixture is crucial to
achieving
2o adequate removal of dyes from the hair. More preferably the bicarbonate
salt or salts of
the invention should be present in a large excess of the amount needed to
react with all of
the hydroxide present in the product.
Examples of bicarbonate salts which can be employed in this manner include but
are not limited to sodium bicarbonate, potassium bicarbonate, ammonium
bicarbonate,
lithium bicarbonate, and guanidine bicarbonate. When ammonium bicarbonate and
guanidine bicarbonate are the salts of choice, effective color removal from
the dyed hair is
achieved at concentrations of bicarbonate lower than those of potassium and
sodium
bicarbonates. It is, however, preferred that the total bicarbonate content of
the bleaching
composition remain within the range of the mole percents previously determined
to
3o provide the desired color removal.
Example 14
14
CA 02333506 2000-11-28
WO 99/60993 PCT/US99J11741
In this example, bicarbonate salts were generated in situ by reaction of a
carbonate
salt with an acid. As a control, sodium carbonate was used to replace the
bicarbonate in
the compositions of Examples 1 through 13. However, the carbonate based
compositions
failed to remove color from the dyed hair. The degree of lift obtained was
comparable to
the control formula which contained only hydrogen peroxide and ammonia (i.e.
little or no
change in the color of the dyed tresses). However, when a proton donor
(succinic acid) in
an amount capable of converting the majority of the carbonate to its
bicarbonate form was
added to the bleaching solution, the degree of dye removal obtained was
identical to that
observed with the sodium bicarbonate compositions of Example 1 through 13.
1o In a second part of this example, guanidine carbonate was substituted for
the
sodium bicarbonate in the solutions of Example 1 through 13. Once again, there
was little
or no change in the color of dyed tresses after this treatment. But when
guanidine
bicarbonate was generated in solution by the reaction of guanidine carbonate
with succinic
acid, the acid being present in an amount capable of converting the majority
of the
carbonate to its bicarbonate form, the color of the dye was effectively
removed from the
tress. Further, the degree of dye removal in this experiment actually exceeded
that which
was obtained with sodium bicarbonate.
Any carbonate salt capable of conversion to bicarbonate by the action of a
proton
donor can be used in this embodiment of the present invention. Any material
capable of
2o donating a proton to convert carbonate to bicarbonate can be used in this
embodiment of
the present invention. Examples of other carbonate salts which can be employed
in this
manner include but are not limited to sodium carbonate, potassium carbonate,
ammonium
carbonate, lithium carbonate, and guanidine carbonate. Examples of proton
donors which
can be employed in this manner include but are not limited to inorganic acids,
organic
acids, and organic compounds which can act as proton donors within the pH
range set
forth in earlier portions of this document. It is understood, however, that it
is the
bicarbonate anion content of the bleaching composition rather than the
residual carbonate
or carbon dioxide which governs the ability of the final oxidizing mixture to
remove dyes
from keratin fibers.
