LU86314A1 - PROCESS FOR DYEING HUMAN KERATINIC FIBERS WITH 5,6-DIHYDROXYINDOLE AND A METAL ANION - Google Patents

Description

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Process for dyeing human keratin fibers with 5,6-dihydroxyindole and a metal anion.

The dyeing of human keratin fibers, and in particular of human hair, with the aid of 5,6-dihydroxyindole, is well known and has been the subject of various French patents of the applicant No. 1,133,594, 1,166 172, 2,390,158 and French patent application 2,536,993.

Among the hair dyeing methods described in these various documents, the possibility has been mentioned of using, as oxidation catalyst, various metal salts such as the manganese, cobalt, iron, copper, silver. The last patent application recommends the use of cupric ions in alkaline solution but also of metal ions such as those of iron, cobalt, manganese, silver, titanium, zirconium, tantalum, chromium, nickel, palladium, platinum, gold, mercury, cadmium, zinc, tin, antimony, lead and bismuth.

; These various processes use metal cations used as "melanogenesis promoters" or "oxidation catalysts".

The use of potassium permanganate or sodium dichromate has already been recommended in hair dyeing, but under conditions such that these derivatives could only react in the hair in their reduced form, that is to say - say 25 metal cations.

The Applicant has discovered, which is the subject of the invention, that it was possible to significantly improve the dyeing power of 5,6-dihydroxyindole by pretreating human keratin fibers with a metal anion having a good affinity for keratin and having a redox potential greater than that of 5,6-dihydroxyindole.

- - The composition containing the metal anion is at acidic pH which also has advantages, such a composition being less aggressive than at alkaline pH.

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The advantages of this pretreatment are manifested in particular during repeated coloring treatments on the same hair or for dyeing "unnatural" hair, that is to say already sensitized by a cosmetic treatment such as bleaching or perming.

5 Without this explanation being limiting, the Applicant believes that the anion, once fixed on the hair, acts as an oxidant with respect to 5,6-dihydroxyindole.

A subject of the invention is therefore a process for dyeing human keratin fibers, in particular human hair, using a pretreatment with a metal anion having a good affinity for keratin, this pretreatment being followed by the application of 5 , 6-dihydroxyindole.

Another object of the invention is constituted by a device with several compartments, or. Dyeing "kit" allowing the implementation of the process according to the invention.

Other objects of the invention will appear on reading the description and the examples which follow.

; The process for dyeing human keratin fibers, and in particular human hair, according to the invention is essentially characterized by the fact that one successively applies: (a) a composition at acidic pH, containing in a medium cosmetically acceptable, an anion of a metal having an affinity for keratin and having a redox potential greater than that of 5,6-dihydroxyindole, and (b) a composition containing, in a cosmetically acceptable medium, 5, 6-dihydroxyindole.

The redox potential, extrapolated to pH 0, of the 5,6-dihydroxyindole being + 0.25 volts / μl, the anions used in accordance with the invention must therefore have a higher redox potential , under these conditions, to that of the dye.

The particularly preferred anions consist of the permanganate (MnO 4) and bichromate (C 4 O 4) anions and which derive more particularly from potassium permanganate and sodium bichromate.

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The composition containing the metal anions preferably has an molarity in anion greater than 10 mol / 1000 g, and preferably -2 -1 situated between 10 mol / 1000 g and 10 mol / 1000 g. This corresponds for MnO to a concentration greater than 0.012 g% and ranging from ^ 2-5 preferably between 0.12 and 1.18 g%, and for C ^ Oy a concentration greater than 0.022 g%, and preferably ranging from 0 , 22 and 2.16 g%.

The composition containing the anion is at a pH below 5, and preferably close to 3. The pH is adjusted with acidifying agents having no reducing effect on the anions, and more particularly with inorganic acids. such as preferably sulfuric acid.

The pretreatment composition may also contain other inorganic and cosmetically acceptable adjuvants. By way of example, mention may be made of silicas or clays, making it possible in particular to thicken or swell this composition. It does not contain adjuvants that can reduce anion.

This composition is preferably aqueous and has a viscosity sufficient for application to the head.

The composition containing 5,6-dihydroxyindole is preferably adjusted to a pH between 7 and 9 using an alkali-nizing agent, inorganic or organic, known per se. For this purpose, there may be mentioned as basifying agents ammonia or amines such as monoethanolamine, diethanolamine, triethanolamine, morpholine, diethylamine, hydroxylamine.

The concentration of 5,6-dihydroxyindole can vary between 0.5 and 2% by weight, and preferably between 1 and 1.5% by weight relative to the total weight of the composition.

This composition may contain, in addition to water, various cosmetically acceptable solvents, among which mention may be made of lower C 1 -C 4 alkanols such as ethanol, isopropanol, tert-butyl alcohol, monomethyl ethers. , monoethyl or monobutyl of ethylene glycol and monoethyl ether acetate of ethylene glycol. The solvents are used in proportions preferably between 1 and 30% by weight, and more particularly between 3 and 20%.

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This composition can also contain other adjuvants usually used in cosmetics such as surfactants, electrolytes, antioxidants, buffers, perfumes, etc. These compositions can also be thickened, in particular with agents chosen from sodium alginate, gum arabic, guar gum, biopolymers such as xanthan gum, cellulose derivatives such as methylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, carboxy-methylcellulose and various polymers having thicker functions such as derivatives of acrylic acid. These compositions can also be thickened with mineral thickening agents such as bentonite. The thickening agents are preferably present, in proportions of between 0.1 and 5% by weight, and in particular of between 0.5 and 3% by weight relative to the total weight of the composition.

An embodiment of the invention may also consist in storing the dye in an anhydrous medium as described in French patent No. 2,390,158 of the applicant and in mixing this composition just before use with a cosmetically acceptable aqueous medium.

The process according to the invention essentially consists in applying, firstly and for a period of 3 to 30 minutes, preferably 5 to 20 minutes, the composition containing the anion defined above, at room temperature of the range from 25 25 to 35 ° C. It is possible possibly to accelerate the treatment by a slight heating up to about 40 ° C.

The hair is rinsed. After this treatment, the dye composition is applied for a period of 2 to 10 minutes, rinsing with water and optionally shampooing and rinsing again.

Another object of the invention is constituted by a device with several compartments, or "dye kit", comprising in a single presentation, a plurality of containers, one of which contains

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5 the coloring composition, the other anion, and possibly a third containing the aqueous cosmetic medium when the dye is stored in anhydrous form.

The pretreatment composition can be packaged in two parts, one containing the anion in the form of an acidic aqueous solution, the other containing a thickened acidic aqueous solution. It is understood that these various compartments are intended to be mixed just before use.

The coloring process according to the invention may possibly also be preceded or followed by other cosmetic treatments.

known in themselves ..

The following examples are intended to illustrate the invention without, however, being limiting in nature.

ψ 6 EXAMPLE 1

A stock solution of stable potassium permanganate is prepared by dissolving 1.58 g of KMnO ^ in 100 ml of water (final volume) adjusted to pH 3 with ^ SO ^. This solution is kept in a bottle protected from light.

To a gel prepared by kneading 7 g of silica, Aerosil 200 (Degussa) with 85 grams of water brought to pH 3 with t ^ SO ^, 9 g of the mother solution of potassium permanganate are intimately incorporated with stirring.

10 The hair is covered with the gel thus prepared using a spatula or a brush.

The pose lasts 10 minutes.

The hair is rinsed with water to remove the gel.

Before use, a thick solution is prepared containing: 15 - NH4C1 5.0 g - Cellosize WP03H 5.0 g - NH40H qs pH 9.0 - Water qs 80 g

1 g of 5,6-dihydroxyindole, dissolved beforehand in 20 g of anhydrous ethanol, is incorporated immediately before use and very quickly.

The pretreated hair is covered with this solution.

The pose lasts 5 minutes.

The hair is abundantly rinsed with water. A sodium lauryl sulfate shampoo is applied to the head.

The initially gray hair, 90% white, has become black.

EXAMPLE 2

The preprocessing is identical to that of Example 1.

20 A thickened solution is prepared before use containing: - Dipotassium hydrogen phosphate 5.6 g> - Potassium dihydrogen phosphate 2.2 g - Cellosize WP03H 5.0 g - HCl or NaOH qs pH 7.0 25 - Water qs 80g

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1 g of 5,6-dihydroxyindole, previously dissolved in 20 g of anhydrous ethanol, is incorporated just before use and very quickly.

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The pretreated and rinsed hair is covered with this solution.

5 The installation lasts 5 minutes.

The hair is abundantly rinsed with water. A sodium lauryl sulfate shampoo is applied to the head.

The initially gray hair, 90% white, has taken on a very intense gray hue.

10 EXAMPLE 3

The mother solution of potassium permanganate is that described in Example 1.

A gel is prepared by mixing 7 g of silica, Aerosil 200 (Degussa) with 76 g of water brought to 3 with ^ SO ^; 18 g of the mother solution of potassium permanganate are incorporated intimately with stirring.

The hair is covered with gel and the installation lasts 5 minutes.

The hair is rinsed with water.

The same dye composition and the same process as that described in Example 1 are used to dye this hair.

20 The initially gray hair, 90% white, has become black.

EXAMPLE 4

The mother solution of potassium permanganate is that described in Example 1.

25 A thickened solution is prepared by mixing 15 g of clay,

Gel White H / USP with 70 g of water. The pH is adjusted to 3 with a minimum of sulfuric acid. 11.5 g of potassium permanganate stock solution are then incorporated.

The final weight is adjusted to 100 g with a little water pH 3 30 (H2SO4).

The hair is covered with this thickened solution,

The pose lasts 5 minutes.

The hair is rinsed with water.

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Before use, a thickened solution is prepared containing: - NH4C1 5.0 g - Carbopol 940 0.7 g - NH ^ OH qs fold 9.0 5 - Water qs 80 g

1.2 g of 5,6-dihydroxyindole, dissolved beforehand in 20 g of ethanol, are incorporated immediately before use and very quickly.

The pretreated hair is covered with this solution.

The pose lasts 5 minutes.

10 The hair is thoroughly rinsed with water. A sodium lauryl sulfate shampoo is applied to the head.

The initially gray hair, 90% white, has become black.

EXAMPLE 5 A potassium dichromate solution is prepared by dissolving 2.94 g of I ^ C ^ Oy in 100 ml of water (final volume), adjusted to pH 3 with H ^ SO ^. This solution is kept in a bottle protected from light.

A thickened solution is prepared by mixing 15 g of clay, 20 Gel White H / USP with 50 g of water. The pH 3 is adjusted with sulfuric acid. 30 g of potassium dichromate stock solution are then incorporated.

The final weight is adjusted to 100 g with a little water at pH 3 with H2so4.

The hair is covered with this thickened solution.

The pose lasts 10 minutes.

The hair is rinsed with water.

Before thickening, a thickened solution of 5,6-dihydro-xyindole is prepared, as in Example 4.

The pretreated hair is covered with this solution.

The pose lasts 5 minutes.

The hair is abundantly rinsed with water. Sodium lauryl sulfate shampoo is applied.

The initially gray hair, 90% white, has become black.

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The trade names used in the examples denote the following products: CARBOPOL 940: homopolymer of crosslinked acrylic acid

by a polyfunctional agent sold by 5 the GOODRICH Company

CELLOSIZE WP03H: hydroxyethylcellulose sold by the

UNION CARBIDE company.

GEL WHITE H / USP: Montmorillonite sold by the company GEORGIA KAOLIN.

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Claims (15)

1. A process for dyeing human keratin fibers, characterized in that there is applied to these fibers: (a) a composition at acid pH containing, in a cosmetically acceptable medium, an anion of a metal having good affinity for keratin and having a redox potential greater than that of 5,6-dihydroxyindole, and (b) a composition containing in a cosmetically acceptable medium 5,6-dihydroxyindole. 2. Method according to claim 1, characterized in that · the anion is a permanganate or a dichromate. 3. Method according to claim 2, characterized in that one uses potassium permanganate or sodium dichromate. 4. Method according to one of claims 1 to 3, characterized by —3 15 the fact that the anion is present at a molality greater than 10 mol / 1000 g. 5. Method according to any one of claims 1 to 4, characterized in that the pH of the composition containing the anion is between 2 and 5 and that it is adjusted with mineral acids. 6. Method according to claim 1, characterized in that the composition containing the anion is in the form of an aqueous composition containing inorganic adjuvants capable of giving it a viscosity allowing application to the head. 7. Method according to any one of claims 1 to 6, characterized in that the 5,6-dihydroxyindole is present in proportions of between 0.5 and 2% and preferably between 1 and 1.5% by weight relative to the total weight of the composition used in the second step. 8. Method according to any one of claims 1 to 7, characterized in that the pH of the composition containing 5,6-dihydroxyindole is between 7 and 9. 9. Method according to any one of claims 1 to 7, characterized in that the composition containing the dye is aqueous and additionally contains a solvent chosen from lower alkanols "4 11 C ^ -C ^, monornethyl ethers , raonoethyl and monobutyl of ethylene glycol or monoethyl ether acetate of ethylene glycol. 10. Method according to any one of claims 1 to 9, 5 characterized in that the composition containing the dye also contains cosmetically acceptable adjuvants chosen from antioxidants, buffers, perfumes, surfactants. 11. Method according to any one of claims 1 to 10, 10 characterized in that an anhydrous solution of 5,6-dihydroxyindole is prepared beforehand in an organic solvent and that at the time of application, mixing with said solution a cosmetically acceptable aqueous medium. 12. Method according to any one of claims 1 to 11, characterized in that the composition applied in the first step is maintained in contact with the hair for a period of 3 to 30 minutes, that its application is followed by a rinsing with water and the composition applied in the second step is maintained in contact with the hair for a period of 2 to 10 minutes followed by rinsing with water, and optionally with a shampoo and a new rinsing. 13. Multi-compartment device or “Kit” for dyeing hair, characterized in that one of the compartments comprises at least one composition containing, in a cosmetically acceptable medium, the anion as defined in any one of claims 1 to 3, that the other compartment contains the composition containing 5,6-dihydroxyindole, as defined in any one of claims 1 and 7 to 11, intended to be applied successively to human keratin fibers . 14. Device with several compartments according to claim 13, characterized in that one of the compartments contains the composition containing in a cosmetically acceptable medium the anion as defined in any one of claims 1 to 3, that the another compartment contains 5,6-dihydroxyindole in medium N 4 - 12 * anhydrous solvent and that the third compartment contains an aqueous cosmetic medium, the contents of the second and third being i intended to be mixed just before use. 15. Device with several compartments according to claim 5 13 or 14, characterized in that one of the compartments contains the anion as defined in any one of claims 1 to 3 in acid solution, than the other compartment contains a thickened acidic aqueous solution, that the third compartment contains 5,6-dihydroxyindole in an anhydrous solvent medium, and that the fourth compartment contains an aqueous cosmetic medium, the contents of the first two compartments and the contents of the last two compartments being intended to be mixed just before use. Drawings: ......... îancn »s ____./.âupages tooth ....... 4 ....... cover page ........ 3 ... .... description pages ........ 4. ; · -: κ · “3 of claim. . ; description Luxembourg, h 2 0 FEV. 1986 The mandaiairo; Me AlairtififiiKavii / a „t>