FI77572C - FOERFARANDE FOER FAERGNING AV HAOR OCH HAORFAERGNINGSFOERPACKNING. - Google Patents

Description

77572

The present invention relates to a method for coloring hair and to a hair coloring kit used in the method.

The color of the hair is due to the separate natural pigment particles in its structure - melanin. Research into melanin and melanogenesis has intensified over the past 40 years, with the result that 10 interest has focused on hair coloring with materials that most closely resemble those natural substances that affect hair color. Melanin biosynthesis involves the conversion of tyrosine via dihydroxyphenylalanine (dopa) to melanin via a number of intermediates, including 5,6-dihydroxyindole.

In addition to the fact that it is generally desirable to dye the hair in a simple manner and with a dye which is essentially a substance which gives the hair its natural color, there is also a dye which can be used as a short-term hair dye and removed at any time and reliably and quickly. way.

Patents have been published covering embodiments for coloring hair using melanin precursors, e.g. tyrosine, L-dopa, L-dopa esters and 5,6-dihydroxyindole. U.S. Patents 2,539,202, 2,875,769 and 3,698,852 relate to L-dopa as a starting material. U.S. Patents 2,934,396, 3,194,734 and 3,993,436 disclose 5,6-dihydroxyindole as a starting material. The main disadvantages of these systems are the time required for color development, the uncertainty of development and its uncontrollability, and the need to add compounds such as p-phenylenediamine and various coupling agents to adjust the tone.

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In the method disclosed in U.S. Patent 2,934,396, the hair is first treated with an acidic or neutral solution of 5,6-dihydroxyindole, then the excess solution is dried off and the oxidant or oxidizing solution is allowed to act on the hair until the desired tone is developed. In one of the methods disclosed in the patent, ambient air oxygen is utilized while the second solution contains an alkalizing agent and a cobalt or manganese compound as an oxidation accelerator. However, the main use is an ammonia-laden solution of an oxidant such as, for example, hydrogen peroxide or an alkali metal or ammonium iodate, periodate or persulphate. When the desired shade has developed, the hair is rinsed, washed with shampoo-15 la rinsed again and dried.

U.S. Patent 3,194,734 is defined as an improvement over the aforementioned U.S. Patent 2,934,396 because previously in the process of the patent, the dyeing, which is the oxidative polymerization of 5,6-dihydroxyindole to melanin-20, simultaneously competes with the oxidative degradation of the resulting dye. indole losses, unevenness of results with hair, and the fact that it is difficult to determine when the process must be stopped by rinsing.

Therefore, this later patent proposes a method in which an aqueous alkaline composition containing 5,6-dihydroxyindole and ammonia or an amine is kept in contact with the hair until the desired shade is obtained. Alternatively, certain methyl derivatives of 5,6-dihydroxyindole can be used to obtain lighter shades in a two-step process in which the hair is first impregnated with an aqueous solution of an acidic or pH-neutral solution of such a methyl derivative, then briefly dried and then developed in the next step using an oxidant. 35 aqueous solution.

The present invention is based on the finding that, unlike the prior art, using H2O2 oxidants in a separate step or in combination with 5,6-dihydroxyindole to obtain different shades, vastly better results can be obtained when using a metal salt as an accelerator of melanogenesis.

The invention relates to a method for coloring hair, which method is characterized in that the particles to be dyed are contacted with a solution of a metal which promotes the formation of melanin from 5,6-dihydroxyindole, after which the hair is rinsed and then the hair is contacted. , With 6-dihydroxyindole, where contact with the solution is maintained until the desired darker color is achieved, after which the hair is rinsed or shampooed and, if desired, the hair is contacted with a hydrogen peroxide solution for up to 15 minutes until the desired color is achieved, after which the hair is rinsed again 20.

The invention also relates to a hair coloring kit for use in the method described above, characterized in that it consists of a single package having a plurality of containers and comprising a first container containing a solution of an effective amount of a melanin-promoting metal and having an alkaline pH; a second container containing a solution of an effective amount of 5,6-dihydroxyindole and having an acidic pH, wherein a vapor space containing a non-oxidizing gas is maintained in said second container above the solution; a third container containing an alkalizing agent, wherein the vapor space in said second container is of sufficient volume so that said third container or the contents of said third container fit into said steam space; and optionally a fourth container containing the hydrogen peroxide solution.

4,77572 In a particularly suitable embodiment of the method according to the invention, the hair is contacted with an alkaline solution containing copper ions, suitably an aqueous solution, after which the hair 5 is rinsed and contacted with a solution of 5,6-dihydroxyindole, preferably an aqueous solution. The contact of the hair with the 5,6-dihydroxyindole solution is maintained until the desired darker color is achieved and then the hair is rinsed or washed with 10 shampoos. If a color other than gray or black is desired, a shade is obtained by the HgCl 2 treatment following the above steps. Thus, it can be seen that the basic difference of this method from all previously known methods of dyeing 5,6-dihydroxyindole with 15a1 is that in all cases except the final color is black, the hair is first dyed gray or black and the final the desired shade is then developed by bleaching with hydrogen peroxide solution.

According to the present invention, unless a black or gray shade is desired, hair dyed with melanin formed from 5,6-dihydroxyindole is bleached with a solution containing hydrogen peroxide. The term "hydrogen peroxide" as used in the specification and claims is intended to mean hydrogen peroxide or any other component that forms hydrogen peroxide in aqueous solution, such as urea peroxide. This bleaching or color determination step differs from the conventional oxidation treatment used in conventional hair bleaching. In conventional bleaching, the natural color of the hair is removed by bleaching when it is desired to color the hair a shade that is lighter than the natural color of the hair. In this case, the natural color of the hair is bleached over a relatively long period of time using a strong oxidizing solution, usually containing hydrogen peroxide and an additional 35 bleach-promoting persalts at a pH of about 19. This bleaching step generally tends to weaken or otherwise damage the hair.

77572 The bleaching step of the present invention does not involve conventional bleaching because the hydrogen peroxide solution used in the present invention does not contain added bleaching agents such as persalts; it is suitable for use at a pH of less than 10, preferably about 9; and the time required for lightening is only no more than about 15 minutes to obtain the lightest shades. Thus, bleaching, a color-generating oxidation step, in accordance with the present invention is significantly faster than conventional bleaching and is not used to bring bleaching beyond the natural color of the hair or the color that the hair had prior to performing the method of the invention.

The difference between the bleaching according to the invention and the conventional bleaching is assumed to be due to the new dyeing step of the invention. In naturally colored hair, the melanin pigment is distributed throughout the structure, i.e. on the inside of the hairline. This means that bleaching natural melanin dye in the hair with strong bleach such as hydrogen peroxide with added persalt requires a considerable amount of time for the bleach to penetrate through the unpigmented peripheral layer or shell into the hairline. In the method of the present invention, the color is believed to be distributed substantially to the outer layer of the hair body, and the bleaching hydrogen peroxide does not require the presence of bleach-promoting persalts or an extended exposure time to achieve and whiten the colorant. Due to the shorter exposure time and penetration into the outer layer, the bleaching step of the present invention does not tend to damage or weaken the hair, as is the case with conventional bleaching.

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It is further believed that the dyes formed in accordance with this invention are unique in that the melanogenesis-promoting metal forms a complex with the melanin formed during dyeing.

5 The affinity of the complexing metal for melanin is considered to be greater than its affinity for hair keratin. Therefore, the reactivity of the dye formed by the melanin-metal complex with hydrogen peroxide is higher than the reactivity of melanin without metal. This is supported by the finding that the melanin / copper complex formed in accordance with this invention can be bleached more rapidly with hydrogen peroxide than natural melanin even if the copper salt is dissolved in the hydrogen peroxide used to bleach natural melanin. Thus, the metal not only promotes the formation of melanin in the dyeing step of this invention but is also believed to affect the ease and speed of the bleaching step. For this reason, we distinguish the bleaching-20 step of this invention, which can be completed in less than 15 minutes, from conventional bleaching, which is of various qualities and generally requires a time well over twice its length and requires bleaching agents in addition to hydrogen peroxide.

The method of the present invention can also be used to dye hair that has already been dyed with conventional hair permanent dyes or semi-permanent dyes. If the original dye is stable to a bleach solution that is weaker than conventional hair bleaches, the coloring and bleaching steps of this invention will not destroy the initial hair color at the times used for bleaching, regardless of whether the initial color is a natural hair color or not. Thus, the hair dyed by the present method can be bleached again to said initial color, whether this bleaching is carried out the next day or considerably later.

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If this method is intended to dye the hair to a shade that is lighter than the natural shade of the hair or lighter than the shade to which the hair was dyed by conventional methods, then the hair must be bleached lighter or even bleached completely before using the method of this invention.

In this case, the bleaching treatment of the present invention can be used to obtain any shade that is darker than the shade initially obtained by bleaching, and then the hair can be bleached to any shade of color or, if desired, the shade obtained by first bleaching can be preserved.

If the desired shade is lighter, it is not necessary to dye the hair completely black, but it is sufficient to dye it to a lighter or darker gray. When the toner is then bleached in the next step, it initially lightens to a lighter or darker shade of brown depending on whether it was colored lighter or darker gray in the initial steps. Of all 20 melanogenesis accelerators studied, only Cu was found to promote melanin formation up to intense black color.

The other accelerator metals studied seem to aid staining only up to lighter or darker shades of gray. In our experiments, longer exposure to hair or higher concentrations of metal accelerators did not cause an increase in the depth of color formed.

In the coloring step, treating the hair with a solution of melanogenesis accelerator before treatment with a solution containing 5,6-dihydro-30-oxyindole improves the color depth. Any metal or transition metal ion capable of accelerating melanogenesis is believed to be suitable for this purpose. These include, for example, iron, cobalt, manganese, copper, silver, titanium, zircon.

35 Tantalum, chromium, nickel, palladium, platinum, gold, mercury, cadmium, zinc, tin, antimony, lead, bismuth. etc. solutions. Metal salts 8,77572 can be used alone or in mixtures. With the exception of copper (II) solutions, it was generally found necessary to use a chelating agent such as citric acid, citrate, ethylenediaminetetraacetic acid, ascorbic acid and the like to keep the metal in solution.

Expressions such as "melanogenesis accelerator" and "melanogenesis accelerator metal salt" and variations of such terms are intended to refer to solutions containing one or more metals that accelerate the formation of color in the particle within a maximum of 20 minutes from contact with the hair. With a solution of 6-dihydroxyindole, whether or not a particular metal or combination of metals can act as an accelerator of melanogenesis can be determined by routine experimentation by examining its ability to form a melanin dye by the method of this invention.

The melanogenesis accelerator found to be the most suitable is Cu 2+, which causes a considerable acceleration of staining, and the resulting color can reach all darknesses up to hard black. Although Fe 2+ also works well, it is not as recommended as copper due to solubility problems in certain OH ranges and other considerations. Furthermore, when applied to copper) ion at about pH 9 or above, preferably at pH 25.5, no chelating agent is required because no insoluble residues are detected in the solution. Monoethanolamine or other nitrogen-containing alkalizing agents such as other alkanolamines, ammonia, etc. can be suitably used to adjust the desired pH. Alkali metal hydroxides only work well if a chelating agent is also used to maintain the solution form. An additional advantage of alkaline pH is that it swells the hair and this allows for better coloring. If copper (II) ion is used, it is absolutely preferable to first soak the hair with a solution containing copper (II) ion and, after rinsing or drying, to soak the hair with a solution containing 5,6-dihydroxyindole. Intermittent rinsing of the hair or drying of its surface is necessary in order to prevent the formation of a washable superficial dye, since the formation of a color in the hair body itself is desired.

The term "rinsing" is intended to include suction-drying, wiping, or any other method of removing the solution from the surface of the hair. It takes about 2-20 minutes to dye the hair to the maximum achievable color depth when using a melanogenesis metal accelerator, but when using copper (II) -10 ions, the time is required even at the fastest end of this fast time range. As can be seen, the use of copper (II) ion thus brings numerous advantages over those obtained with other accelerators of melanogenesis.

The solution containing 5,6-dihydroxyindole is preferably at pH 8 or above. It is recommended that it not exceed a pH of 9.5, as the instability of the solutions increases as the pH increases. After the hair is dyed black or gray, it is recommended to wash with shampoo instead of just rinsing. This is because the toner-20 that may have formed on the surface of the hair may not be rinsed off and may then later rub off the surface. The shampoo removes such a surface dye and thus prevents abrasion.

The concentration of 5,6-dihydroxyindole is not critical, but suitably concentrations of about 0.5 to about 2% by weight of the solution may be used for reasons of economy and to control the rate of coloration. As stated, the concentrations of the corresponding ingredients are not critical. Therefore, where the concentration is defined in the specification or claims as an "effective amount", this definition means that the amount used is suitable for the intended purpose. This purpose may be different, such as different color depth, greater economy in the price of the ingredients, different reaction rate, stability of the solution, etc. Whatever this purpose is, the efficiency of the amount of the ingredient can be determined by routine experiments. All percentages throughout the specification and claims are by weight unless otherwise indicated.

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If the desired shade is other than black, then after the hair is dyed and possibly washed with shampoo, it is subjected to a bleaching step by contacting it with a dilute hydrogen peroxide solution for a time sufficient to achieve the desired shade. Any hydrogen peroxide solution useful in bleaching or bleaching the hair can be used at this stage, but it was found that a content of about 1% to about 6% is sufficient. When bleaching hair mus-10 from this or gray, the color changes through various progressively lighter shades and the process can be stopped by rinsing the hair once it has reached the desired shade. The natural tone of the hair can be easily restored after an initially darker shade is no longer desired. An aqueous solution of hydrogen peroxide is suitably used above pH 8, preferably at pH 9. Relatively slow but not too slow bleaching lasting up to 15 minutes allows the user sufficient control to stop the process at any desired shade or natural hair tone. In this way, the competing staining and bleaching reactions and associated disadvantages associated with known methods are eliminated and better, more positive control of the entire process is achieved, regardless of whether the dyeing is done in the salon or by the user.

The method of the present invention also allows for the selective coloring of discrete portions of the hair to provide light spots, streaks and other cosmetic effects.

To maintain stability, the 5,6-dihydroxyindole solution is preferably stored at an acidic pH, preferably at about pH 4.5. In addition, the acidic pH solution should suitably be stored under anaerobic conditions such as nitrogen, with the atmosphere above the solution being filled with nitrogen during packaging, preferably for about 77572 minutes, rather than with air. One method of dealing with the problem is to store a small volume of nitrogen in the flask above the solution, this space being of a suitable size so that an alkalizing agent can be added before use. However, this can be inconvenient and therefore suitably concentrated, such as a 12.5% aqueous alcohol solution of 5,6-dihydroxyindole or a completely alcoholic solution in which it dissolves well, can be stored at acidic pH in a small full container until it 10 is meant to be used. Immediately before use, the contents of this small bottle can be transferred to a larger bottle, which may contain a pre-thickened alkali solution, so that an alkaline 5,6-dihydroxyindole solution is obtained immediately before use. Another way is to store the alkalinizing agent in a small bag made of selectively soluble material and then the whole bag can be dropped into a space above the acidified 5,6-dihydroxyindole solution, thus avoiding the need for the user to handle a potentially strong alkalizing agent. . Alternatively, when a small amount of concentrated, acidified 5,6-dihydroxyindole solution is to be added to the alkaline solution, the former could be kept in a selectively soluble bag that could be completely transferred to the aqueous alkaline solution to avoid the user pouring liquid from one container to another. .

It has been found that the addition of a small amount such as 1% by weight of a surfactant such as sodium lauryl sulfate to at least one of the solutions containing metal and 5,6-dihydroxyindole can improve the flow properties of the compositions, thereby improving their spread to the hair. In the same way, it is possible to reduce the staining of the scalp and to improve the flow properties of the solutions by adding a small amount such as 0.5% by weight of sa-35 blowing agent to each solution such as Carbomer t i2 7 7 5 7 2 940, an acrylic acid crosslinked polymer with a polyfunctional agent, sold by Goodrich Chemical Company under the name Carbopol 940. Other agents that can be used to adjust the desired flow properties can be determined by routine experimentation, as such flow control agents are well known in the art of selecting ingredients for hair treatment compositions. It is also known in the art of hair treatment compositions that certain flow modifying additives 10 may be unsuitable for certain compositions. For example, it was found that additives such as cocamidopropylhydroxysultaine sold by Lonza Chemical Co. under the name Lonzaine CS, and hydroxypropylmethylcellulose sold by Dow Chemical Co. as Methocel, were apparently unsuitable for use with the compositions of this invention because the color formed was not as deep when using these agents. Other ingredients known per se such as conditioners, perfumes, antistatic agents and the like may be included in the compositions or may be applied to the hair after the method.

The following examples further illustrate this invention.

Example 1 The following accelerator composition was prepared:

CuSO4.5H2O 1% Carbomer 940 0.5%

Sodium laurilsulfate 1% monoethanolamine pH 9.5 30 water 100

The following dye composition was prepared: sodium acetate 1.2% 5,6-dihydroxyindole 1.2% Carbomer 940 0.47% 35 ethanol 19.7% sodium hydroxide to pH 8.5

II

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The hair was impregnated with the catalytic composition for five minutes and then rinsed with water. Next, the hair was impregnated with a composition containing 5,6-dihydroxyindole for 5 minutes. The resulting black-stained hair was washed with shampoo to remove all melanin from the hair surfaces.

Example 2

Light brown hair was dyed black by the procedure of Example 1. Next, the hair was saturated with a 6% aqueous solution of hydrogen peroxide at pH 9. After 10 minutes, the original light brown tone of the hair was achieved and the hair was rinsed. The same procedure was repeated, but the hair was bleached for 6 minutes to obtain a darker brown hue. Three to 15 weeks later, the hair was bleached for an additional 3.5 minutes to obtain the original light brown hue.

Example 3

The same procedure as in Example 1 was repeated for blonde hair, except that the content of 5,6-dihydroxyindole 20 was only 0.5%. Staining was performed for only 2 minutes from light gray to medium gray. After the hair was washed with shampoo, they were soaked in a 6% aqueous solution of hydrogen peroxide at pH 9 to lighten the hair to a light brown color within 6 minutes.

Example 4

The copper sulfate solution of Example 1 was replaced using 0.25% FeSO based on a composition premixed with citric acid in a ratio to avoid precipitation of iron at alkaline pH, and monoethanolamine was added to adjust the pH to 9.5.

The procedure of Example 1 was repeated except that the solution containing 5,6-dihydroxyindole did not contain Carbomer 940. The hair was exposed to 14,77572 catalyst solution for 10 minutes, then rinsed and saturated with a solution containing 5,6-dihydroxyindole for 10 minutes until the original light brown color of the hair became clearly darker.

5 Example 5

The same procedure as in Example 1 was repeated except that the 5,6-dihydroxyindole solution was used first and then, and after rinsing, the catalyst-containing solution. The color formed on the hair was not as strong as in the case of Example 1.

Claims (9)

1. A process for staining here, characterized in that the hair to be stained brines gas in contact with a solution of a metal which promotes melanin formation from 5,6-dihydroxyindole, after which the hair is rinsed and the hair thereafter contacted with a solution of 5,6-dihydroxyindole, maintaining contact with the solution for as long as a desired darker color is achieved, then rinsing or washing with shampoo and, if desired, contacting the solution with a solution of hydrogen peroxide for a maximum of 15 minutes until a desired hue has been achieved, after which the herbivore eats are rinsed. Process according to claim 1, characterized in that the metal is copper or iron. 3. A process according to claim 1 or 2, characterized in that the solution containing metal is an alkaline solution containing copper (II) ions. 20 Process according to any of the preceding patent claims, characterized in that the solution containing the metal has a pH of at least 8 and that the solution containing 5,6-dihydroxyindole has a pH of at least 8. 5. A process according to claim 3, characterized in that the solution containing copper (II) ions has a pH of at least 9, that the solution containing 5,6-dihydroxindole has a pH of at least 8 and that the solution containing hydrogen peroxide has a pH of at least 8. 6. A process according to claim 3, characterized in that at least one of the solutions containing copper (II) ions or 5,6-dihydroxyindole contains a thickening agent, surfactant, anti-static agent and / or perfume. 7. Dyeing pack for use in the method of claim 1, characterized in that it is comprised of a single pack of several containers and comprising a first container.