LU87429A1 - POLYMER PARTICLE PRODUCT COMPRISING MELANIC PIGMENTS, PREPARATION METHOD AND USE THEREOF, PARTICULARLY IN COSMETICS - Google Patents

Abstract

Product consisting of polymer particles, wherein the polymer particles are chosen from particles of: (a) polymers derived from keratin, where appropriate modified; (b) silk fibroin; (c) polymers derived from chitin, where appropriate deacetylated; (d) synthetic polymers chosen from: (i) crosslinked polymethyl methacrylate; (ii) crosslinked poly- beta -alanine; (iii) hollow microspheres of vinylidene chloride/acrylonitrile copolymer; (iv) porous microspheres of polyamide 12, polyamide 6 or copolyamide 6/12; (v) silicone powders consisting of gums, resins or organopolysiloxane elastomers, these particles having a particle size of less than 100 microns and containing a natural or synthetic melanin pigment at the surface and/or in the polymer network, this pigment being either formed beforehand and absorbed by the particles or formed in situ by oxidation of an indole dye.

Description

Description filed in support of an invention patent application for: "Product based on polymer particles containing melanin pigments, its preparation process and its use, in particular in cosmetics" L'OREAL SA 14, rue Royale 75008 PARIS France

Product based on polymer particles comprising melanin pigments, its preparation process and its particular use in cosmetics. 7 '' "'-

The present invention relates to new products consisting of fine polymer particles, comprising melanin pigments, to their process of preparation and to their use, in particular in the field of cosmetics, for making up hair and skin, protection of the human epidermis against UV radiation and hair coloring.

The color of the hair, of the skin and of the hairs of human origin mainly comes from the melanin pigments secreted by the melanocytes and, moreover, the protective role of the melanin pigment is well known against solar radiation.

These pigments, of natural origin, include in particular black or brown pigments which are called eumelanins.

Their natural biosynthesis takes place in several stages by polymerization of the oxidation products of an amino acid: tyrosine and one of its oxidation products is 5,6-dihydroxyindole which in turn polymerizes into eumelanin.

Attempts have already been made to manufacture in vitro pigments based on pseudomelanin or on melanin-like compounds which are non-toxic and non-allergenic and which prove, in particular, to be advantageous in makeup compositions for the skin, hair, eyelashes and eyebrows, for which pigments with good safety are sought compared to the pigments usually used, such as pigments based on iron oxide.

The Applicant has discovered, which is the subject of the invention, that it was possible to prepare with good yield, a product consisting of fine particles "based on polymers and on a melanin pigment.

The pigment formed is called melanin pigment. by oxidation of 5,6-dihydroxyindole, optionally combined with 2-carboxy 5,6-dihydroxyindole.

By analogy and simplification, the term "melanin pigment" will also be understood to mean the pigment formed by oxidation of each of the compounds of formula (I) defined below.

These new products can be used as pigments or adjuvants in various technical fields where recourse is had to the use of pigmented particles, such as the field of paint, of cosmetics, etc.

The products in accordance with the invention are used more particularly as pigments in the cosmetic industry, in particular for the protection of the human epidermis against the harmful effects of solar radiation, for making up the skin, hairs, eyelashes and eyebrows and hair coloring.

The present invention therefore relates to a product consisting of fine particles of polymers, comprising melanin pigments.

Another object of the invention is constituted by the preparation of such a product. The invention also relates to the cosmetic application of such products, in particular in the make-up of the skin and the hairs (eyelashes and eyebrows), the protection of the human epidermis against UV radiation and the coloring of hair. Autres.objets du invention will appear on reading the · description and examples which follow, _ ... The · ... pxpduit conforms to .l'invention ..est ..... essentially characterized by the fact that it consists of polymer particles having a particle size less than 100 microns and comprising, on the surface and / or in the polymer network, a melanin pigment resulting from the oxidation of at least one indolic dye, corresponding to the formula :

(I) in which: R- | represents a hydrogen atom or a C1-C4 alkyl group; R2 and R3, identical or different, represent a hydrogen atom, a C1-C4 alkyl group, a carboxyl group or a C1-C4 carbonyl alkoxy group; R4, R5, Rg and R7, identical or different, represent a hydrogen atom, a C1-C4 alkyl radical, amino, carboxyl, C1-C4 carboxyalkyl, C1-C4 carbonyl alkoxy, C- | -c4 alkoxy carbonylalkyl C1-C4, carbamyl, halogen, mono- or polyhydroxyalkyl in C1-C4, aminoalkyl in C1-C4, an OZ group, in which Z denotes hydrogen., _ .. alkyl. linear or branched at C | -C20 "an aralkyl group (Ci-C4), a formyl group, an acyl group at C2" C20 linear or branched, an alkenoyl group at C3-C20 linear or branched, a group -S1R11R12R13 'a group -P (0) (0R3) 2, a .group RgOSC ^ -; the radicals R4 and R5, or else R5 and Rg, or else Rg and R7 can form, together with the carbon atoms to which they are attached, ring optionally containing a carbonyl group, a thiocarbonyl group, a group (ORg) or a group ^^ CRgRio? provided that at least one of the radicals R4 to R7 represents an OZ group or else that R4 and R5, or else R5 and Rg, or else Rg and R7 form a ring, Rs and Rg represent a hydrogen atom or a lower C1-C4 alkyl group, R-jq represents a C1-C4 alkoxy group or a mono- or dialkyl group ( C- | -C4) amino, Rn, R12 and R13f, identical or different, represent C1-C4 / linear alkyl groups or branched, and the corresponding salts of alkali, alkaline earth, ammonium and amines.

The indolic dyes are preferably chosen from 4-hydroxyindole, 4-hydroxy 5-methoxyindole, 4-hydroxy 5-ethoxyindole, 5-hydroxyindole, 2-carboxy 5-hydroxyindole, 5-hydroxy 6-methoxyindole, 6-hydroxy indole, 6-hydroxy 7-methoxyindole, 5-methoxy 6-hydroxyindole, 7-hydroxyindole, 5, ö-dihydroxyindole, 1-methyl 5,6-dihydroxyindole, 2-methyl 5, 6-dihydroxyindole, 3-methyl 5,6-dihydroxyindole, 2,3-dimethyl 5,6-dihydroxyindole, (5 or 6) -acetoxy (6 or 5) -hydroxy indole.

The particle size of these particles is generally greater than 0.01 micron and is preferably between 0.01 and 50 microns and in particular between 0.1 and 20 microns.

They are preferably spherical.

The polymers which can be used according to the invention are polymers which are essentially insoluble in the reaction medium and are chosen from natural or synthetic, organic or inorganic polymers, with a crosslinked, crystalline or amorphous network, having a molecular weight of between 5,000 and 5,000,000.

The essentially insoluble nature of the polymer is justified by essentially economic reasons insofar as the melanin pigment must * * be fixed on a solid particulate support, to form the product in accordance with the invention.

The solubility of the polymers in the reaction medium should preferably not exceed 10%.

The organic or synthetic polymers are in particular chosen from polymers derived from keratin, chitin or cellulose and polyamides or homo or copolymers resulting from the polymerization of mono or polyethylene, aliphatic or aromatic monomers, with crosslinked network, crystalline or amorphous.

The polymers derived from keratin are in particular chosen from animal or human keratins, derived, for example, from materials chosen from hair, wool, skin, hair, bristles, feathers, scales and more particularly hooves, the horn.

These materials are preferably washed and / or degreased, then reduced to particles. Other polymers derived from keratin are chemically modified keratins, having a molecular weight of between 10,000 and 250,000, and in particular partially hydrolyzed keratin (or keratin hydrolyzate), obtained from skins which are rich in it. sulfur products and having a molecular weight between 50,000 and 200,000. This hydrolyzate is preferably obtained by moderate alkaline hydrolysis.

Products of this type are for example sold under the name of RERASOL by the company CRODA. . Other modified keratins are sulfonic keratins with a molecular weight of between 10,000 and 100,000, obtained from goose or chicken feathers or more advantageously from hooves or horns.

This keratin is obtained by oxidation of all or part of the disulfide bonds of the cystine groups of keratin into cysteic acid groups: SO3H, the oxidation being advantageously carried out in an acid medium, such as formic acid, by means of an oxidizing agent. , such as hydrogen peroxide.

The polymers derived from chitin consist of chitin which is a natural polymer, the most important source of which is found in the shell of crustaceans, such as crabs, lobsters, lobsters, etc. The chitin is prepared according to a process described, in particular, in the work of RAA MUZ ZARELLI "CHITIISi", published by PERGAMCISi PRESS OXFORD, 1977, pages 89-100 and 207-217. It is also possible to use its deacetylated derivative known under the name of chitosan, obtained by saponification of the acetyl groups of chitin.

Chitosan, as commercially available, is partially acetylated and contains 70 to 90% by weight of chitosan. It can also be used in the form of its insoluble salts / such as sulfates and phosphates. Products of this type are sold for example under the denominat.ion__de .KYTEX by the company HERCULES.

The cellulosic polymers are chosen more particularly from microcrystalline celluloses / such as the products sold under the name AVICEL by the company PMC.

Among the synthetic polymers, mention may particularly be made of polyethylene, polypropylene, polystyrene, polymethyl methacrylate, crosslinked polymethyl methacrylate, such as the product sold under the name MICROPEARL M 305 by the company SEPPIC. Other polymers are in particular chosen from crosslinked poly-ß-alanine, as described in French patent 2,530,250, or also presented., Advantageously in the form of microspheres having a very low size dispersity, 85% in weight having a particle size between 28 and 46 microns. These poly-β-alanines are obtained according to a process consisting in polymerizing between 60 and 100 ° C, and preferably around 80 ° C, of acrylamide in a mixture of t-butanol / toluene solvents, in ratios between 1 : 24 and 10: 1 and preferably between 1: 6 and 6: 1, in the presence of a polymerization initiator, an octadecene-maleic anhydride copolymer as a suspending agent, then subjecting the suspension of poly-ß- alanine obtained on crosslinking using a dialdehyde, such as glutaraldehyde. The polymerization initiator is preferably sodium or potassium tert-butoxide (0.1 to about 2 mole% relative to the acrylamide). > Glutaraldehyde is used in the form of an aqueous solution between 20 and 25% and in a proportion of between 1 and 15% by weight relative to the weight of starting acrylamide.

It is also possible to use, as polymers, products known under the name of micro-sponges, such as crosslinked polymers of styrene / divinylbenzene or of methyl methacrylate / ethylene glycol dimethacrylate or of vinyl stearate / divinylbenzene, as described in the patents. W0-88 / 01164 and US-A-4690 825.

Such polymers are essentially constituted by beads of crosslinked polymers comprising an internal network of pores, capable of retaining the melanin pigment. Other polymers of this type are hollow microspheres of a copolymer of vinylidene chloride and acrylonitrile, sold under the name EXPANCEL by the company KEMA NORD; porous polyamide 12, polyamide 6 or copolyarcide 6/12 microspheres, sold under the name ORGASOL by the company ΑΤΟ-CHIMIE. These microspheres preferably have a particle size between 10 and 50 microns.

The products in accordance with the invention are prepared according to a process consisting essentially in mixing with air and at a temperature preferably ambient and up to 50 ° C., the indolic compound of formula (I) and the particles of the polymers described above, in an essentially non-solvent medium for the polymer, as defined above.

If no oxidizing agents are used other than the oxygen in the air, the operation is carried out at a preferably alkaline pH, in which case the pigment gradually forms and fixes on the surface of the particles and / or in the network. or the pores thereof. It is also possible to use in the presence of oxygen a metal oxidation catalyst such as the cupric ion.

These products can also be prepared by immediately forming the melanin pigment, using an oxidizing agent such as hydrogen peroxide, periodic acid and its water-soluble salts and derivatives, permanganates and dichromates, such as sodium. or potassium, sodium hypochlorite, potassium ferricyanide, ammonium persulfate, silver oxide, ferric chloride, lead oxide (Pb IV), sodium nitrite, by addition of 'iodide and hydrogen peroxide, the iodide preferably being an iodide of alkali metal, alkaline earth metal or ammonium.

These oxidizing agents can optionally be activated by a pH modifying agent.

For products intended for cosmetic application, hydrogen peroxide, periodic acid and its salts, potassium permanganate, sodium hypochlorite, ammonium persulfate, nitrite of sodium and the iodide / hydrogen peroxide system. The order of addition of the compounds involved in the preparation of the product, in accordance with the invention, is of little importance on condition that the oxidizing agent is incorporated last when it is used without a modifying agent. of pH, and in the case of the iodide / hydrogen peroxide oxidizing system, is introduced lastly, either hydrogen peroxide or iodide.

In the case where a pH modifying agent is used to activate the oxidizing agent, it is preferable to add lastly, namely the oxidizing agent,

When using a keratin hydrolyzate, the pH of the medium should preferably be less than 5, in order to avoid the solubilization of the modified keratin.

When a sulfonic keratin is used, the medium is either essentially alcoholic or aqueous, in which case the pH must be less than 7.

When using chitosan, the aqueous medium should preferably have a pH greater than 5.8. ...... As indicated above, the reaction medium is an essentially non-solvent medium for the polymer considered. It is preferably constituted by water and it can optionally be constituted by a mixture of water and solvent, the solvent being chosen from ethyl alcohol, isopropyl alcohol, tert-butyl alcohol, monomethyl ethers, monoethyl, ethylene glycol monobutyl, ethylene glycol monoethyl ether acetate.

These solvents must, moreover, be able to dissolve the indolic dye.

When the medium consists of a water-solvent mixture (s), the solvents are present in concentrations of preferences of between 0.5 and 90% by weight relative to the total weight of the composition and in particular between 2 and 50% by weight and preferably between 2 and 20% by weight.

Their nature is chosen and their proportion is adjusted according to the solubility criteria of indole derivatives and the insolubility criterion of the polymer.

In the process according to the invention, the indolic dye is preferably used in weight proportions of between 0.1 and 10% and preferably between 1 and 5% by weight, the polymer representing 0.05 to 50% by weight. and preferably 4 to 30% by weight, the rest of the reaction mixture generally consisting of water or a water / solvent mixture.

The oxidants are used in sufficient amounts to oxidize the indolic dye and form the melanin pigment.

When the iodide ion is used to form the melanin pigment, it is preferably used in proportions of 0.07 to 4% and in particular between 0.7 and 3%, observing an indolic dye / I "between 0.6 and 6.

The proportions are determined relative to the weight of the reaction medium.

The product in the form of particles is preferably used in the cosmetic field in which it is preferably presented in the spherical form. It can be added in conventional cosmetic carriers at a concentration of between 0.2 and 35% by weight and preferably between 2 and 20% by weight relative to the total weight of the composition, to lead to cosmetic compositions protecting the skin. epidermis, make-up products, in particular eyelashes, eyebrows or skin, such as eyeshadows, blushes, liners also called "eyeliners", mascaras for eyelashes and eyebrows, or dye compositions for hair. These cosmetic supports are known in themselves.

These compositions can be in the form of a lotion, thickened lotion, gel, cream, milk, powder, stick and optionally be packaged as an aerosol and can be in the form of a foam.

When the compositions are used for making up the skin, the eyelashes and the eyebrows, they can in particular be in solid or pasty, anhydrous or aqueous form, such as oil-in-water or water-in-oil emulsions or alternatively suspensions. These compositions have the advantage of being stable and of exhibiting good safety.

When the compositions are used for the protection of the human epidermis against UV radiation, they therefore constitute so-called "solar" compositions, they can be in the form of suspensions or dispersions in solvents or fatty substances, under form of emulsions such as creams and milks, ointments, gels, solid sticks or aerosol foams.

In all cases, when they are used in the form of emulsions, they may also contain surfactants well known in the art, chosen from anionic, nonionic, cationic or surfactants. amphoteric.

The makeup compositions and the sun compositions may also contain fatty substances, organic solvents, silicones, thickeners, softeners, sun filters, anti-foaming agents, moisturizing agents, perfumes, preservatives, agents. antioxidants, fillers, sequestrants, treatment agents such as anionic, cationic, nonionic, amphoteric polymers, as well as their mixtures, propellants, basifying or acidifying agents.

The fatty substances can consist of an oil or a wax or their mixture, fatty acids, fatty alcohols, petrolatum, paraffin, lanolin, hydrogenated lanolin, acetylated lanolin.

The oils are chosen from animal, vegetable, mineral or synthetic oils and in particular hydrogenated palm oil, hydrogenated castor oil, petroleum jelly oil, paraffin oil, Purcellin oil.

The waxes are chosen from animal, fossil, vegetable, mineral or synthetic waxes, among which mention may be made of beeswax, Carnauba, Candelilla, sugar cane, Japanese wax, ozokerites, Montan, microcrystalline waxes, paraffins.

The compositions may also contain, in addition to ultrafine particles comprising melanin pigments, as defined above, other pigments generally used in cosmetics, in particular pearlescent pigments which also make it possible to vary the colorings which may be obtained.

The following examples are intended to illustrate the invention without, however, being limiting in nature. EXAMPLE 1

A polymer and melanin pigment powder is prepared by adding, successively with magnetic stirring, in a beaker, the following ingredients: - 5,6-dihydroxyindole 0.9 g - Ethyl alcohol 22.5 g - Water 44.0 g - Microcrystalline cellulose sold by FMC Corp. under the name AVICEL PH 103 and micronized (particle size between 0.1 and 1 micron) 9.0 g - Potassium iodide 1/2 g - H2O2 (10 volume aqueous solution) 22.4 g

After filtration, washing with water and then with ethyl alcohol, a black ultrafine powder is obtained. EXAMPLE 2

A polymer and melanin pigment powder is prepared by adding thereto successively with stirring - magnetic - in a beaker, the following ingredients: - 5,6-dihydroxyindole 1.2 g - Ethyl alcohol 19.7 g - Water 57.8 g - Potassium iodide 1.7 g - Polystyrene sold by the company ÜCIB, micronized (particle size between 0.1 and 1 micron) 9.8 g - H2O2 (20 volume aqueous solution) 9.8 g

After filtration, washing with water and then with ethyl alcohol, an ultrafine dark gray steel powder is obtained. EXAMPLE 3

A polymer and melanin pigment powder is prepared by adding, successively with magnetic stirring, to a beaker, the following ingredients: - Polymethyl methacrylate sold by the company UCIB, micronized (particle size between 0.1 and 1 micron) 17, 5 g - 5,6-dihydroxyindole 1.9 g - Water 77.5 g - Sodium periodate 2.9 g

After filtration, washing with water and then with ethyl alcohol, a black ultrafine powder is obtained. EXAMPLE 4

A polymer and melanin pigment powder is prepared by adding / successively with magnetic stirring, in a beaker, the following ingredients: - Crosslinked poly-ß-alanine (approximately 2 microns) 4.9 g - 5,6-dihydroxyindole 1.0 g - Water 91.4 g - Sodium nitrite 2.7 g - HCl (1 N) qs pH = 4

After filtration, washing with water and then with ethyl alcohol, a black ultrafine powder is obtained. EXAMPLE 5

A polymer and melanin pigment powder is prepared by adding, successively with magnetic stirring, to a beaker, the following ingredients: - 5,6-dihydroxyindole 2.4 g - Ethyl alcohol 26.9 g - Water 53.8 g - Polypropylene sold by JANSEN, micronized (particle size between 0.1 and 1 micron) 13.4 g - Potassium periodate 3.5 g

After filtration, washing with water and then with ethyl alcohol, an ultrafine silver gray powder is obtained. EXAMPLE 6

A polymer and melanin pigment powder is prepared by adding / successively with magnetic stirring / in a beaker / the following ingredients; - 6-hydroxyindole 1/7 g - Ethyl alcohol 13.2 g - Water 69.5 g - Ammonium iodide 1.1 g - Cross-linked poly-ß-alanine (particle size between 0.1 and 1 micron) 9, 9 g - H2O2 (20 volume aqueous solution) 4.6 g

After filtration, washing with water and then with ethyl alcohol, an ocher ultrafine red powder is obtained. . EXAMPLE 7

A polymer and melanin pigment powder is prepared by adding, successively with magnetic stirring, to a beaker, the following ingredients: 3-methyl 5,6-dihydroxyindole 0.3 g - ethyl alcohol 12.2 g - water 50, 9 g - Polymethyl methacrylate sold by the company ÜCIB, micronized (particle size between 0.1 and 1 micron) 10.2 g - Ammonium persulfate 1.0 g - Water 25.4 g

After filtration, washing with water and then with ethyl alcohol, a very dark brown ultrafine powder is obtained. EXAMPLE 8

A polymer and melanin pigment powder is prepared by adding, successively with magnetic stirring, to a beaker, the following ingredients: - 4-hydroxyindole "0.5 g - Ethyl alcohol 14.8 g - Water 64.2 g · - Polystyrene sold by the company üCIB, micronized (particle size between 0.1 and 1 micron) 19.3 g - Potassium permanganate (1.2 g

of an aqueous solution 1 N) 0.19 g MA

After filtration, washing with water and then with ethyl alcohol, a very light gray ultrafine powder is obtained. EXAMPLE 9

A chitomelanic compound is prepared by adding, successively, with magnetic stirring, in a beaker, the following ingredients: - 5,6-dihydroxyindole 1.5 g - Ethyl alcohol 12.4 g - Water 73.1 g - Potassium iodide 0.7 g - Chitin extracted from crustacean shells, sold under the name CHITIN LS 2970 by the Company

Nancy Serobiological Laboratory 1.6 g - 30 volumes aqueous hydrogen peroxide solution 10.7 g

The pigment is formed upon addition of the oxidant.

After filtration, washing with water and then with ethyl alcohol, a black ultrafine powder is obtained. EXAMPLE 10

A chitomelanic compound is prepared by adding, successively with magnetic stirring in a beaker, the following ingredients: - 5,6-dihydroxyindole 1.1 g - Water 96.0 g - Chitin · extracted from shellfish shells, sold by the Company Nancy Serobiological Laboratory under the name CHITIN LS 2970 1.9 g - Sodium periodate 1.0 g

The pigment is formed upon addition of the oxidant.

After filtration, washing with water and then with ethyl alcohol, a black ultrafine powder is obtained. EXAMPLE 11

A chitomelanic compound is prepared by adding, successively with magnetic stirring in a beaker, the following ingredients: - 6-hydroxyindole 2.8 g - Ethyl alcohol 24.9 g - Water 69.2 g - Chitin extracted from shellfish shells, sold by the Laboratoire Sérobiologique de Nancy under the name CHITIN LS 2970 1.4 g - Ammonium persulfate 1.7 g

The pigment is formed upon addition of the oxidant.

After filtration, washing with water and then with ethyl alcohol, an ultrafine powder of wine-colored tint is obtained. EXAMPLE 12

A chitomelanic compound is prepared by adding, successively with magnetic stirring in a beaker, the following ingredients: - 5-methoxy 6-hydroxyindole 0.8 g - Ethyl alcohol 31.7 g - Water 63.4 g - Chitin extracted from carapace shells crustaceans, sold by the Laboratoire Sérobiologique de Nancy under the name CHITIN LS 2970 0.9 g - Potassium permanganate in

1 N aqueous solution: 3.2 g 0.51 g MA

The pigment is formed upon addition of the oxidant.

After filtration, washing with water and then with ethyl alcohol, an ultrafine powder, ash purple mauve is obtained. EXAMPLE 13

A chitomelanic compound is prepared by adding, successively with magnetic stirring in a beaker, the following ingredients: - 2,3-dimethyl 5,6-dihydroxyindole hydrobromide 3.0 g - Ethyl alcohol 27.6 g - Water 66.3 g - Chitin extracted from shellfish shells, sold by the Société Sérobiologique de Nancy under the name CHITIN LS 2970 1.7 g - Sodium nitrite 1.4 g

The ultrafine powder, after filtration, washing with water and then with alcohol, is purple in color. EXAMPLE 14

A chitomelanic compound is prepared by mixing, with magnetic stirring, the following compounds: - Chitosan sold under the name KYTEX M by the company HERCULES 10.7 g

- Water alkalized by NaOR

Water 75.9 g

NaOR 1.4 g - 5.6-dihydroxyindole 1.7 g - Ethyl alcohol 10.3 g To the chitosan powder in suspension in alkaline water, 5.6-dihydroxyindole in solution in ethyl alcohol is added . The black precipitate obtained is separated by filtration, washing with water, then with ethyl alcohol. EXAMPLE 15

A keratin-melanic compound is prepared by - adding, successively under magnetic stirring, in a beaker, the following ingredients: - Keratin (brown hair washed and reduced to powder) 2.1 g - 5.6-dihydroxyindole O, 8 g - Ethyl alcohol 21.1 g - Water 76.0 g

The reaction is left to perfect in air (15 minutes) before filtering the beige gray ultrafine powder obtained. EXAMPLE 16

A keratin-melanic compound is prepared by adding, successively with magnetic stirring, to a beaker, the following ingredients: - 5,6-dihydroxyindole 1.0 g - Ethyl alcohol 24.4 g - Water 57.0 g - Keratin (hair washed and powdered browns) 1.3 g

- NaOH in aqueous solution 1 ISi (16.3 g) 0.65 g MA

After filtration, washing with water and then with ethyl alcohol, an ultrafine medium gray powder is obtained. EXAMPLE 17

A keratin-melanic compound is prepared by adding, successively with magnetic stirring, to a beaker, the following ingredients: - Keratin (white hair washed and reduced to powder) 0.8 g - 7-hydroxyindole 1.0 g - Potassium iodide 1.0 g - Ethyl alcohol 14.0 g - Water 69.2 g - H2O2 (30 volume aqueous solution) 14.0 g

After filtration, washing with water and then with ethyl alcohol, a very dark brown ultrafine powder is obtained. EXAMPLE 18

A keratinomelanic compound is prepared by adding, successively with magnetic stirring, to a beaker, the following ingredients: - Keratin (white hair washed and reduced to powder) 1.9 g - 4-hydroxyindole 1.2 g - Ethyl alcohol 23, 1 g - Water 70.1 g - Sodium periodate 3.7 g

The pigment is formed upon addition of the oxidant.

After filtration, washing with water and then with ethyl alcohol, a bluish black ultrafine powder is obtained. EXAMPLE 19

A keratinomelanic compound is prepared by adding, successively with magnetic stirring in a beaker, the following ingredients: - Keratin (from brown hair washed and reduced to powder) 1/4 g - 5-methoxy 6-hydroxyindole 2.8 g - Ethyl alcohol 41.7 g - Water 51.4 g - Potassium permanganate

(1 N aqueous solution: 2.7 g) 0.43 g MA

The pigment is formed upon the addition of the oxidant.

After filtration, washing with water and then with ethyl alcohol, a black ultrafine powder is obtained. EXAMPLE 20 A keratinomelanic compound is prepared by adding, successively with magnetic stirring in a beaker, the following ingredients: - Keratin (brown hair washed and reduced to powder) 1.1 g - 6-hydroxyindole 1.1 g - Ethyl alcohol 22.0 g - Water 74.7 g - Ammonium persulfate 1.1 g

The pigment is formed upon addition of the oxidant.

After filtration, washing with water and then with ethyl alcohol, a black ultrafine powder is obtained. EXAMPLE 21

A ké.ratinomélanique compound is prepared by adding, successively with magnetic stirring in a beaker, the following ingredients: - Keratin (white hair * washed and reduced to powder) 1.0 g - 3-methyl 5,6-dihydroxyindole 1.0 g - Ethyl alcohol 9.8 g - Water 87.6 g - sodium nitrite 0.6 g - HCl (1 N) qs pH = 4.9

The pigment is formed upon addition of the oxidant.

After filtration, washing with water and then with ethyl alcohol, an ultrafine brown powder is obtained. EXAMPLE 22

A keratinomelanic compound is prepared by adding, successively with magnetic stirring in a beaker, the following ingredients: - Keratin (white hair washed and reduced to powder) 3.2 g - 4-hydroxyindole 3.2 g - Ethyl alcohol 32.0 g - Water 60.8 g - Sodium periodate 0.8 g

The periodate is formed upon addition of the oxidant.

After filtration, washing with water and then with ethyl alcohol, a bluish medium gray ultrafine powder is obtained. EXAMPLE 23

A keratinomelanic compound is prepared by adding / successively with magnetic stirring in a beaker, the following ingredients: - Keratin (washed white hair reduced to powder) 1.0 g - 5-hydroxyindole 1.7 g - Ethyl alcohol 9.8 g - Water 86.5 g - Ammonium persulfate 1.0 g

The pigment is formed upon addition of the oxidant.

After filtration, washing with water and then with ethyl alcohol, an ultrafine olive-brown powder is obtained. EXAMPLE 24

A keratin-omelanic compound is prepared by adding, successively with magnetic stirring in a beaker, the following ingredients: - sulfonic keratin (from bovine hooves) 4.3 g - 5.6-dihydroxyindole 0.9 g - iodide sodium 0.9 g - Ethyl alcohol 87.0 g - E2 ° 2 (30 volume aqueous solution) 2.2 g

The pigment is formed upon the addition of hydrogen peroxide.

After filtration, washing with water and then with ethyl alcohol, a black ultrafine powder is obtained. EXAMPLE 25

A keratinorr.elanic compound is prepared by adding, successively with magnetic stirring in a beaker, the following ingredients: - sulfonic keratin (from bovine hooves) 6.1 g - 6-hydroxyindole 1.8 g - ammonium iodide 0 , 4 g - Ethyl alcohol 81.9 g - H2O2 (30 volume aqueous solution) 9.8 g

The pigment is formed upon the addition of hydrogen peroxide.

After filtration, washing with ethyl alcohol, an ultrafine dark brown powder is obtained. EXAMPLE 26 (I) Preparation of crosslinked poly-β-alanine.

In a 3 liter reactor, fitted with an "anchor" type agitator with a diameter of 90 mm, a nitrogen inlet, an addition funnel and a distillation column head, 934 g of toluene, 1666 g of tertiobutanol and 1.4 g of maleic anhydride / octadecene copolymer (sold under the name PA-18) are introduced by the company GULF. After heating this mixture to 70 ° C., 100 g of acrylamide are added thereto. The temperature is then brought to 10 ° C. and 120 ml of the water / toluene / tert-butanol azeotropic mixture are distilled. After the end of the distillation, the reaction mixture is cooled to 80 ° C., and the stirring speed is adjusted to 550 rpm. Then a solution of 2.24 g of potassium tert-butylate in 40 g of tert-butanol is added over 10 min. The addition funnel is rinsed with 120 ml of toluene. After 7 hours of stirring at 80 ° C., it is allowed to return to ambient temperature. Then added to the mixture, drop by drop, 7.5 ml of 12N hydrochloric acid. To the suspension of the microspheres obtained, 100 ml of water are added with vigorous stirring (550 rpm), at 50 ° C. in 15 minutes, then 15 ml of a 25% glutaraldehyde solution in 20 minutes. After having maintained stirring for 4 hours at this temperature, it is allowed to return to room temperature. After decantation, the supernatant solvents are removed and the microspheres are washed twice with 500 ml of ethanol. The spin after each wash is carried out by centrifugation (3500 rpm). Washing with 15 liters of water is then carried out continuously, then the water is removed to a final mixing volume of 600 ml.

The crosslinked poly-β-alanine is then dried by lyophilization and 92 g of white powder are obtained, the diameter of the microspheres being on average 0.37 + 0.2 microns. (II) Preparation of particles comprising the melanin pigment

Procedure (IIa) 0.55 g of 5,6-dihydroxyindole are dissolved in 40 g of water, then the pH is adjusted to 9 with a solution of NaOH (1N). 10 g of the microspheres prepared according to (I) are introduced therein, soaked with a few drops of ethanol. The mixture is heated to 40 ° C., then stirred on a rotary evaporator for 40 minutes. A colorless dispersion is obtained. 1.25 g of CUSO4.5H2O in solution in 10 g of water are introduced there. In the suspension, of brown coloring, oxygen is bubbled for 2 hours. The blackened microspheres are left stirring overnight, at ambient temperature, under an oxygen atmosphere, then washed until the washing waters are colorless and neutral; the particles are dried by lyophilization.

Procedure (Ilb) a) 40 g of microspheres prepared according to (I) are swollen with a solution composed of 10 g of

Cu.SO4.5H2O and 400 g of water. The mixture is stirred for 1 hour at room temperature, then lyophilized. b) 0.2 g of 5,6-dihydroxyindole are dissolved in 80 g of water, then the mixture is adjusted to p Eî: 9 with a solution of NaOH (1N). In this solution, 20 g of microspheres prepared above (a) are dispersed. The oxidation of the blackened suspension is completed according to the procedure (IIa). EXAMPLE 27

A polymer and melanin pigment powder is prepared by successively adding, with magnetic stirring, to a beaker, the following ingredients: - 5,6-dihydroxyindole 5.0 g - Ethyl alcohol 6.6 g

- Crosslinked methyl polymhacrylate, sold under the name MICROPEARL M 305 by SEPPIC 3.7 g - Ammonium persulfate 1.5 g - Water qs 100.0 g

After filtration, washing with water and then with alcohol, a very dark gray ultrafine powder is obtained. EXAMPLE 28

A polymer and melanin pigment powder is prepared by adding, successively with magnetic stirring in a beaker, the following ingredients: - 5,6-dihydroxyindole 11.1 g - Ethyl alcohol 16.7 g - Water 55/5 g - Polyamide 12 sold under the name ORGASOL 2002 D Natural by the company ATO-CHEMISTRY 11.1 g - pure NaOH 5.6 g

The reaction is left to perfect in air (4 hours) before filtering the black ultrafine powder obtained which is separated by filtration, washing with water, then with alcohol. EXAMPLE 29

A polymer and melanin pigment powder is prepared by adding, successively with magnetic stirring in a beaker, the following ingredients: - 5,6-dihydroxyindole 11.1 g - Ethyl alcohol 16.7 g - Water 55.5 g

- Copolymer of vinylidene chloride / acrylonitrile in the form of a microsphere, sold under the name EXPANCEL 551 WU by the company KEMA NORD 11.1 g - Pure NaOH 5.6 g

The reaction is left to perfect in air (1 hour) before filtering the very dark gray ultrafine powder obtained which is separated by filtration, washing with water, then with alcohol. EXAMPLE 30

A coloring composition is prepared for the treatment of white hair, by mixing the following ingredients: - Product prepared according to Example 26 (Ha or Ilb) 1.0 g - Crosslinked polyacrylic acid, sold under the name CARB0P0L 940 by GOODRICH 0.7 g - N-vinylpyrrolidone-vinyl acetate copolymer, sold by GAP under the name PVP / VA-S-630 2.0 g - Ethanol 17.0 g - Emulsion based on cationic silicone, sold by DOW CORNING under the name DC 929 0.1 g - Triethanolamine qs pH = 6.6 - Water qs 100.0 g

5 g of this composition are applied to a lock of white hair. After drying, the hair is colored in a medium gray shade. EXAMPLE 31

A mascara is prepared with the following composition: - Triethanolamine stearate 15.0 g - Candelilla wax 8.0 g - Carnauba wax 10.0 g - Hydroxy ethyl cellulose 1.0 g - Gum arabic 1.0 g - Product according to Example 24 8.0 g - Methyl parahydroxy benzoate 0.15 g - Propyl parahydroxy benzoate 0.15 g - Deionized water qs 100.0 g

In this example, the product of Example 24 can be replaced by that of Example 25. EXAMPLE 32

An eyeliner of the following composition is prepared: - Propylene glycol 8.0 g - Polyethylene glycol 5.0 g - Isopropanolamine myristate 3.0 g - Xanthan gum 1.0 g - Polyvinyl alcohol 0.5 g - Hydrogenated lanolin 4.0 g - Methyl parahydroxy benzoate 0.1 g - Propyl parahydroxy benzoate 0.1 g - Ethyl parahydroxy benzoate 0.1 g - Mica titanium 5.0 g - Black pigment (product according to Example 18) 7.0 g - Deionized water qs 100.0 g

In this example, the product of example 18 can be replaced for example by those of examples 4, 9, 10, 12, 14, 17, 19, 20, 21, 24, 25. EXAMPLE 33

A foundation of the following composition is prepared: - - - - Stearic acid 2.2 g - Glycerol stearate 3.2 g - Vaseline oil 4.0 g - Isopropyl palmitate 9.0 g - Ethyl palmitate -2 hexyl 8.0 g - Propyl parahydroxy benzoate 0.1 g - Triethanolamine 1.1 g - Glycerin 3.0 g - Propylene glycol 2.0 g - Magnesium alumino silicate 1.0 g - Carboxy methyl sodium cellulose 0, 2 g - Imidazolidinyl urea 0.3 g - Yellow iron oxide 2.0 g - Red iron oxide 1.4 g - Product according to example 20 0.5 g - Titanium dioxide 8.0 g - Talc 5, 0 g - Perfume 0.3 g - Water permuted qs 100.0 g

In this example, the product of example 20 can be replaced by those of examples 1, 6, 11, 15,, 16, 17, 19 or 20, 21. EXAMPLE 34

We prepare the following solar composition; - 2-Octyl-dodecanol-1 10.0 g - Magnesium stearate 4.0 g - Beeswax 5.0 g - Hydrogenated lanolin 1.0g - Lanolin 4.0 g - Sorbitan sesquioleate sold under the name ARLACEL 83 over there

Company ICI 4.5 g - Mixture of glycerol monodistearate and potassium stearate (9317) 1.0 g - Vaseline oil 27.0 g - Product prepared according to Example 26 (IIa) or 26 (Ilb) 5, 0 g - Preservatives qs - Perfume qs -fl Water qs 100.0 g

Claims (33)

1. product consisting of polymer particles, having a .granulometry less than 100 microns and comprising on the surface and / or in the polymer network, a melanin pigment resulting from the oxidation of at least one indolic dye corresponding to the formula;

(I) in which: Ri represents a hydrogen atom or a C1-C4 alkyl group; R2 and R3, identical or different, represent a hydrogen atom, a C1-C4 alkyl group, a carboxyl group or a C1-C4 carbonyl alkoxy group; R4, R5, Rô and R7, identical or different, represent a hydrogen atom, a C1-C4 alkyl radical, amino, carboxyl, C1-C4 carboxyalkyl, C1-C4 carbonyl alkoxy, C1-C4 alkoxy C1- C carbonylalkyl C4, carbamyl, halogen, mono- or polyhydroxyalkyl in C1-C4, aminoalkyl in C1-C4, an OZ group in which Z denotes hydrogen, alkyl, linear or branched in C1-C2OF an aralkyl group (C1-C4), a group formyl, a linear or branched C2 ~ C20 'acyl group, a linear or branched C3 ~ C20r alkenoyl group, a linear or branched C3-C2OF alkenoyl group, a group -S1R11R12R13 / a group -P (0) (0R8 ) 2f an R8OSO2- group; the radicals R4 and R5, or else R5 and Rß, or else Rß and R7 which can form, together with the carbon atoms to which they are attached, a ring optionally containing a carbonyl group, a thiocarbonyl group, a group

(ΟΗβ) or a group

; with the proviso that at least one of the radicals R4 to R7 represents an OZ group or else that R4 and Rg, or else R5 and Rß, or else Rß and R7 form a ring, Rs and Rg represent a hydrogen atom or a C1-C4 lower alkyl group, R-jq represents a C1-C4 alkoxy group or a mono- or dialkyl (Ci-C4) amino group, Rn, R12 and R13> identical or different, represent C1-alkyl groups -C4, linear or branched, and the corresponding salts of alkali, alkaline earth metals, ammonium and amines. 2. Product according to claim 1, characterized in that the particle size of the particles is greater than 0.01 micron and it is preferably between 0.01 and 50 microns. 3. Product according to claim 1 or 2, characterized in that the indolic dye is chosen from 4-hydroxyindole, 4-hydroxy 5-methoxy indole, 4-hydroxy 5-ethoxyindole, 5-hydroxyindole, 2 -carboxy 5-hydroxyindole, 5-hydroxy 6-methoxy indole, 6-hydroxyindole, 6-hydroxy 7-methoxy indole, 5-methoxy 6-hydroxyindole, 7-hydroxy indole, 5,6-dihydroxyindole, 1-methyl 5,6-dihy-droxyindole, 2-mlthyl 5,6-dihydroxyindole, 3-methyl 5,6-dihydroxyindole, 2,3-dimethyl 5,6-dihydroxyindole, (5 or 6) -acetoxy (6 or 5) -hydroxy indole. 4. Product according to any one of claims 1 to 3, characterized in that the essentially insoluble in the reaction medium, in which the oxidation reaction takes place and which are chosen from natural or synthetic polymers, organic or inorganic , with a crosslinked, crystalline or amorphous network, having a molecular weight of between 5,000 and 5,000,000. 5. Product according to any one of claims 1 to 4, characterized in that the polymers are chosen from polymers derived from keratin, chitin or cellulose or from polyamides or homo or copolymers resulting from the polymerization of mono or polyethylene, aliphatic or aromatic monomers, with a crosslinked, crystalline or amorphous network. 6. Product according to claim 5, characterized in that the keratins are chosen from animal or human keratins, derived from materials chosen from hair, wool, skin, body hair, silks, feathers, scales, hooves, horn, 7. Product according to claim 5, characterized in that the polymer derived from keratin is a chemically modified keratin, having a molecular weight between 10,000 and 250,000, by hydrolysis or oxidation. 8. Product according to claim 7, characterized in that the polymer derived from keratin is a partially hydrolyzed keratin, obtained from skins and having a molecular weight of between 50,000 and 200,000. 9. Product according to claim 7, characterized in that the modified keratin is a sulphonic keratin, having a molecular weight of between 10,000 and 100,000, obtained from goose or chicken or hoof or horn feathers. 10. Product according to claim 5, characterized in that the polymers derived from chitin consist of -chitin or its deacetylated derivative called chitosan. 11. Product according to claim 5, characterized in that the cellulosic polymers are chosen from microcrystalline celluloses. 12. Product according to claim 5, characterized in that the synthetic polymers are chosen from polyethylene, polypropylene, polystyrene, polymethyl methacrylate, crosslinked polymethyl methacrylate. 13. Product according to claim 5, characterized in that the polymer is a crosslinked poly-ß-alanine. 14. Product according to claim 5, characterized in that the polymers are micro-sponges consisting of crosslinked polymers of styrene / divinylbenzene, methyl methacrylate / ethylene glycol dimethacrylate or vinyl stearate / divinylbenzene. 15. Product according to claim 5, characterized in that the polymer consists of hollow microspheres of copolymers of vinylidene chloride and acrylonitrile or porous microspheres of polyamide 12, polyamide 6 or copolyamide 6/12. 16. A method of preparing a product as defined in any one of claims 1 to 15, characterized in that an indolic dye as defined in claim 1 and a particulate filler are mixed in an aqueous medium polymer, having a particle size less than 100 microns and which then proceeds to the formation of the pigment by oxidation of the indolic dye. 17. The method of claim 16, characterized in that the oxidation takes place slowly. In air,. At alkaline pH. 18. The method of claim 16, characterized in that the oxidation is carried out by oxygen in the presence of a metal catalyst. 19. The method of claim 16, characterized in that the oxidation is carried out by adding oxidizing agents consisting of hydrogen peroxide, periodic acid and its salts, permanganates, bichromates, hypochlorite sodium, potassium ferricyanide, ammonium persulfate, silver oxide, ferric chloride, lead oxide (Pb IV), sodium nitrite. 20. The method of claim 16, characterized in that the oxidation is carried out by addition of an alkali, alkaline earth or ammonium iodide and hydrogen peroxide. 21. The method of claim 16, characterized in that the oxidizing agents are chosen from hydrogen peroxide, periodic acid and its salts, potassium permanganate, sodium hypochlorite, ammonium persulfate, sodium nitrite and the iodide / hydrogen peroxide system. 22. Method according to any one of claims 16 to 21, characterized in that the reaction medium is an essentially non-solvent medium for the polymer considered, consisting of water or a mixture of water and solvent (s) . 23. The method of claim 22, characterized in that the solvent is chosen from ethyl alcohol, isopropyl alcohol, tert-butyl alcohol, monomethyl, monoethyl, monobutyl ethers of ethylene glycol, acetate monoethyl ether of ethyleneglycol. 24. Method according to any one of claims 16 to "23, characterized _pajr JThe fact that the indolic dye is present in weight proportions of between 0.1 and 10% by weight and preferably between 1 and 5% by weight. relative to the weight of the reaction medium, the polymer representing 0.05 to 50% by weight and preferably 4 to 30% by weight relative to the weight of the reaction mixture. 25. Cosmetic composition, characterized in that it contains in a cosmetically acceptable medium, at least one product as defined in any one of claims 1 to 15 or prepared according to the process defined in any one of claims 16 to 24. 26. Composition according to claim 25, characterized in that it is in the form of a lotion, thickened lotion, gel, cream, milk, powder, stick and that it is optionally packaged as an aerosol. 27. The composition as claimed in claim 25, intended to be used for making up the skin, the eyelashes and the eyebrows, characterized in that it is in solid or pasty, anhydrous or aqueous form. 28. Composition according to any one of claims 25 or 26, intended for the protection of the human epidermis against solar radiation, characterized in that it is in the form of a suspension or of dispersion in solvents or bodies oily or in the form of an emulsion, ointment, gel, solid stick or aerosol foam. 29. Composition according to claim 25, characterized in that it contains fatty substances, organic solvents, silicones, thickeners, softeners, sun filters, anti-foaming agents, dea. Moisturizing agents, perfumes, preservatives, antioxidants, fillers, sequestrants, treatment agents, propellants, alkalizing or acidifying agents or fatty substances. 30. Composition according to any one of claims 25 to 29, characterized in that it contains other pigments allowing the colors to be varied. 31. Application of the composition according to claim 25 or 28 / to the protection of the human epidermis. 32. Application of the composition according to claim 25, as a make-up product. 33. Application of the composition according to claim 25, for dyeing human hair.