Compositions and method for temporarily coloring hair using a complex of water soluble melanin and a cationic material

Compositions comprising chemically synthesized or biosynthetic water-soluble melanin and at least one water dispersible cationic material which, when combined with the melanin, forms a composition that is suitable for use as a temporary haircolor. A process for temporarily coloring hair using those compositions.

BACKGROUND OF THE INVENTION 
This invention relates to compositions and methods for temporarily coloring 
hair using chemically synthesized or giosynthetic water-soluble melanin. 
Naturally-occurring melanin is the pigment that gives hair its color. A 
general discussion of the properties and chemistry of melanins may be 
found in Prota, G., "Progress In The Chemistry Of Melanins And Related 
Metabolites," Med. Res. Reviews, 8:525-56 (1988) and Moncrieff, R. W., 
Manufacturing Chemist, XXI, 8, 330-34 (August 1950). The gradual loss of 
melanin, with age, causes hair to turn gray. 
Naturally-occurring melanin pigment itself is unacceptable for use in a 
hair dye composition because it is easily rubbed off the hair and leaves 
hair feeling rough. In the past, one of the best methods for coloring gray 
hair involved the use of naturally-occurring melanin precursors (such as 
5,6 dihydroxyindole (DHI)) that when combined with an oxidant or a metal 
salt, form melanin pigments within the hair shaft. See, for example, U.S. 
Pat. No. 3,194,734 (Seemuller et al.), U.S. Pat. No. 4,808,190 (Grollier 
et al.), and U.S. Pat. No. 4,888,027 (Grollier et al.). However, the use 
of these melanin precursors has many disadvantages. 
The primary disadvantage is that the haircolors initially produced with 
melanin precursors are undesirable achromatic colors (cold grays and 
blacks). Melanin precursor dyed hair must undergo a second treatment step 
with an oxidant such as hydrogen peroxide to achieve natural chromatic 
colors (warm yellows, reds, and browns). See, for example, U.S. Pat. No. 
3,194,734 (Seemuller et al.). In addition, melanin precursors are 
expensive and, because they are highly reactive, difficult to work with. 
The use of melanin precursors also results in undesirable scalp and skin 
staining. 
Furthermore, because melanin precursors penetrate the hair shaft, the 
haircolors produced using melanin precursors are permanent haircolors. 
That is, the haircolor must grow out with the hair. Often, consumers 
prefer to use a temporary haircolor that will wash out after one or two 
shampoos. However, temporary haircolors are unacceptable to consumers 
unless they do not fade in sunlight any more than natural haircolor, do 
not rub off, and do not bleed when in contact with perspiration, rain, or 
swimming pool water. 
Therefore, there exists a need in the art for a composition that produces, 
in a single treatment step, temporary natural-looking haircolor that will 
not fade substantially in sunlight, will not rub off, and will not bleed 
when in contact with water; is inexpensive; will not stain skin; and is 
simple to work with. Applicants have surprisingly found an aqueous 
composition, which comprises chemically synthesized or biosynthetic 
water-soluble melanin and at least one water dispersible cationic 
material, that has each of those characteristics. 
SUMMARY OF THE INVENTION 
It is an object of this invention to provide a composition for temporarily 
coloring hair using chemically synthesized or biosynthetic water-soluble 
melanin. 
It is also an object of this invention to provide a composition that will 
produce a temporary natural-looking hair color that will not fade in 
sunlight any more than natural haircolor, will not rub off, and will not 
bleed when in contact with water. 
It is further an object of this invention to provide an inexpensive 
composition for temporarily coloring hair using chemically synthesized or 
biosynthetic water-soluble melanin. 
It is also an object of this invention to provide a composition for 
temporarily coloring hair that comprises chemically synthesized or 
biosynthetic water-soluble melanin and will not stain skin. 
It is also an object of this invention to provide a composition that is 
simple to work with for temporarily coloring hair using chemically 
synthesized or biosynthetic water-soluble melanin. 
It is also an object of this invention to provide a one step process for 
temporarily coloring hair using chemically synthesized or biosynthetic 
water-soluble melanin. 
In accordance with this invention, an aqueous composition is provided, for 
temporarily coloring hair, comprising chemically synthesized or 
biosynthetic water-soluble melanin and at least one water dispersible 
cationic material. A process for temporarily coloring hair, using that 
composition, is also provided.

DETAILED DESCRIPTION OF THE INVENTION 
The present invention provides an aqueous composition comprising chemically 
synthesized or biosynthetic water-soluble melanin and at least one water 
dispersible cationic material which, when combined with the melanin, forms 
a composition that is suitable for use as a temporary haircolor. The 
chemically synthesized or biosynthetic water-soluble melanins that are 
suitable for use with this invention must have an anionic character and 
should be capable of forming a complex with the water dispersible cationic 
material. 
The amount of melanin required in the composition of this invention will 
vary according to factors such as the carrier used, the starting 
haircolor, and the desired end haircolor. Thus, a tinctorially effective 
amount of melanin should be used. In general, however, the amount of 
melanin required will be about 0.1% to about 5.0%, preferably the amount 
of solubilized melanin will be about 0.2% to about 5.0%. 
The water dispersible cationic materials that may be used in the present 
invention must, when combined with the melanin, be capable of forming a 
composition that is suitable for use as a temporary haircolor. That is, 
the mixture of cationic materials and water-soluble melanin must be either 
water-soluble or water-dispersible under the conditions at which they will 
be used. Preferably, the cationic materials and water-soluble melanin will 
form a stable homogenous solution or emulsion. These water dispersible 
cationic materials will also form a complex with water-soluble anionic 
melanins. Such water dispersible cationic materials include cationic 
surface active agents, cationic surfactants, cationic polymers, and salts 
thereof. Materials that assume a cationic character at a certain pH are 
also water dispersible cationic materials in accordance with this 
invention. Specific water dispersible cationic materials that may be used 
include: dicetyldimonium chloride, Merquat 100, (poly dimethyl diallyl 
ammonium chloride) Merquat 3330 (an aqueous solution of a polyampholyte 
terpolymer consisting of acrylic acid, dimethyl diallyl ammonium chloride 
and acrylamide) and Polyquaternium-11(a quaternary ammonium polymer formed 
by the reaction of dimethyl sulfate and a copolymer of vinyl pyrrolidone 
and dimethyl aminoethylmethacrylate). The water dispersible cationic 
materials are preferably present in amounts sufficient to form a complex 
with substantially all of the melanin in the composition. The ratio of 
melanin to water dispersible cationic material that is useful in the 
composition of this invention varies widely. However, in general, the 
ratio will be from about 1:4 to about 10:1. 
The composition of this invention is stable over time. That is, hair can be 
temporarily dyed immediately after the melanin is combined with the water 
dispersible cationic material, or application of the composition can be 
delayed. 
Although the pH of the composition may not be so low or high as to damage 
hair, the composition is useful at a wide range of pH values. The correct 
pH for a particular composition is a function of the type of water 
dispersible cationic material used and the amount of melanin. In general, 
however, the pH of the composition will be about 4 to about 8. 
In addition to melanin and water dispersible cationic material, it may be 
desirable to include cosmetically acceptable carriers in the compositions 
of this invention. Acceptable carriers vary from simple solutions or 
dispersions with aqueous or alcoholic solvents, to complex mixtures that 
contain thickening agents. The carriers that may be used in accordance 
with this invention must be compatible with chemically synthesized or 
biosynthetic water-soluble melanin. 
It may also be desirable to include in the compositions of this invention 
adjuvants or additives that are commonly found in haircolor compositions, 
in amounts effective to provide their intended function. Such adjuvants or 
additives include solvents, solubilizing agents, thickening agents, 
alkalizing agents, chelating agents, preservatives and fragrances. 
The solvents that may be used include organic solvents or solvent systems 
that are compatible with water-soluble melanin. A number of organic 
solvents are known in the art that are useful for such purposes. These 
organic solvents include alcohols, particularly alkyl alcohols of 1-6 
carbons, especially ethanol and propanol; and glycols of up to about 10 
carbons, especially diethyleneglycol, monobutyl ether, carbitols, and 
benzyl alcohol. 
The thickening agents that may be used in the compositions of this 
invention include: polyvinylpyrrolidone, gum arabic, cellulose derivatives 
such as methylcellulose or hydroxyethylcellulose, and inorganic thickeners 
such as bentonite. 
The additional solubilizing agents that may be used in the compositions of 
this invention include ethoxylated fatty alcohols. 
The preservatives that may be used in the compositions of this invention 
include: methyl- and propyl paraben, 2-phenoxyethanol, DMDMH, and Kathon 
CG. 
The haircolor compositions of this invention may be prepared by methods 
known in the art. 
This invention also provides a process for temporarily coloring hair, which 
comprises applying to the hair an aqueous composition comprising 
chemically synthesized or biosynthetic water-soluble melanin and .at least 
one water disperable cationic material. The haircolor compositions may be 
applied to the hair by conventional techniques known in the art. For 
example, they can be poured over the hair or applied with an applicator. 
The amount of time for which the dye composition must be in contact with 
the hair is not critical. It may vary from about 2 minutes to about 50 
minutes, but is usually from about 5 minutes to about 30 minutes. 
It will be apparent to those skilled in the art that the invention 
described herein can be practiced by other than the embodiments disclosed 
herein, which are presented for the purposes of illustration and not of 
limitation, and the present invention is limited only by the claims that 
follow.