Products based on polymer particles containing melanine pigments, process for their preparation, and their use, particularly cosmetically

Claim 2

Product according to Claim 1, characterised in that the melanin pigment resulting from the oxidation of at least one indole dye corresponds to the formula: in which: R₁ represents a hydrogen atom or a C₁-C₄ alkyl group; R₂ and R₃, which may be identical or different, represent a hydrogen atom, a C₁-C₄ alkyl group, a carboxyl group or a (C₁-C₄ alkoxy)carbonyl group; R₄, R₅, R₆ and R₇, which may be identical or different, represent a hydrogen atom, a C₁-C₄ alkyl radical, a group -NHR (in which R denotes H, C₁-C₄ alkyl, C₁-C₄ hydroxyalkyl, C₂-C₄ polyhydroxyalkyl), an acylamino, carboxyl, C₁-C₄ carboxyalkyl, (C₁-C₄ alkoxy)carbonyl, (C₁-C₄ alkoxy)carbonyl(C₁-C₄ alkyl), carbamyl, halogen, C₁-C₄ mono- or polyhydroxyalkyl or C₁-C₄ aminoalkyl group, a group OZ, in which Z denotes hydrogen, C₁-C₂₀ linear or branched alkyl, an aryl(C₁-C₄ alkyl) group, a formyl group, a linear or branched C₂-C₂₀ acyl group, a linear or branched C₃-C₂₀ alkenoyl group, a linear or branched C₃-C₂₀ alkenoyl group, (sic) a group -SiR₁₁R₁₂R₁₃, a group -P(O)(OR₈)₂, or a group R₈OSO₂-; it being possible for the radicals R₄ and R₅, or alternatively R₅ and R₆, or alternatively R₆ and R₇, to form, together with the carbon atoms to which they are attached, a ring optionally containing a carbonyl group, a thiocarbonyl group, a group 〉 P(O)(OR₈) or a group 〉CR₉R₁₀; with the proviso that at least one of the radicals R₄ to R₇ represents a group OZ, or alternatively that one of the radicals R₄ to R₇ represents -NHR, or alternatively that R₄ and R₆ (sic) or alternatively R₅ and R₆ or alternatively R₆ and R₇ form a ring, R₈ and R₉ represent a hydrogen atom or a C₁-C₄ lower alkyl group, R₁₀ represents a C₁-C₄ alkoxy group or a (C₁-C₄ mono- or dialkyl)amino group, and R₁₁, R₁₂ and R₁₃, which may be identical or different, represent linear or branched C₁-C₄ alkyl groups, and the corresponding alkali metal, alkaline earth metal, ammonium and amine salts.

Claim 3

Product according to Claim 1 or 2, characterised in that the size of the particles is greater than 0.01 µm and is preferably between 0.01 and 50 µm.

Claim 4

Product according to Claim 2, characterised in that the indole dye is selected from 4-hydroxyindole, 4-hydroxy-5-methoxyindole, 4-hydroxy-5-ethoxyindole, 5-hydroxyindole, 2-carboxy-5-hydroxyindole, 5-hydroxy-6-methoxyindole, 6-hydroxyindole, 6-hydroxy-7-methoxyindole, 5-methoxy-6-hydroxyindole, 7-hydroxyindole, 5,6-dihydroxyindole, 1-methyl-5,6-dihydroxyindole, 2-methyl-5,6-dihydroxyindole, 3-methyl-5,6-dihydroxyindole, 2,3-dimethyl-5,6-dihydroxyindole and (5 or 6)-acetoxy-(6 or 5)-hydroxyindole.

Claim 5

Product according to any one of Claims 1 to 4, characterised in that the said polymers are selected from polymers which are insoluble in the reaction medium in which the oxidation reaction proceeds, and in that they have a crosslinked, crystalline or amorphous network and a molecular weight of between 5,000 and 5,000,000.

Claim 6

Product according to any one of Claims 1 to 5, characterised in that the keratins are selected from animal or human keratins capable of originating from materials selected from the hair, wool, skin, hairs, bristles, feathers, scales, hooves and horn.

Claim 7

Product according to any one of Claims 1 to 5, characterised in that the polymer derived from keratin is a keratin modified chemically by hydrolysis or oxidation, having a molecular weight of between 10,000 and 250,000.

Claim 8

Product according to Claim 7, characterised in that the polymer derived from keratin is a partially hydrolysed keratin capable of being obtained from skins and having a molecular weight of between 50,000 and 200,000.

Claim 9

Product according to Claim 7, characterised in that the modified keratin is a sulphonic keratin having a molecular weight of between 10,000 and 100,000, capable of being obtained from goose or chicken feathers or from hooves or horn.

Claim 10

Product according to any one of Claims 1 to 5, characterised in that the polymers derived from chitin consist of chitin or its deacetylated derivative known as chitosan.

Claim 11

Product according to any one of Claims 1 to 5, characterised in that the polymer is a crosslinked poly-β-alanine.

Claim 12

Product according to any one of Claims 1 to 5, characterised 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.

Claim 13

Process for preparing a product as defined in any one of Claims [lacuna] to 12, characterised in that either the indole dye and a particulate charge of polymer having a particle size of less than 100 µm are mixed in an aqueous medium, and in that (sic) formation of the pigment is then carried out by oxidation of the indole dye, or the melanin pigment formed beforehand is dispersed, in finely divided form, in a medium which is non-solvent for the polymer and containing the said particles of polymer, and, after absorption of the pigment, the particles are dried.

Claim 14

Process according to Claim 13, characterised in that the indole dye mixed with the particulate charge of polymer is an indole dye as defined in Claim 2.

Claim 15

Process according to Claim 13 or 14, characterised in that the oxidation is performed slowly in the air at alkaline pH.

Claim 16

Process according to Claim 13 or 14, characterised in that the oxidation is performed with oxygen in the presence of a metal catalyst.

Claim 17

Process according to Claim 13 or 14, characterised in that the oxidation is performed by the addition of oxidising agents consisting of hydrogen peroxide, periodic acid and its salts, permanganates, dichromates, sodium hypochlorite, potassium ferricyanide, ammonium persulphate, silver oxide, ferric chloride, lead (PbIV) oxide or sodium nitrite.

Claim 18

Process according to Claim 13 or 14, characterised in that the oxidation is performed by the addition of an alkali metal iodide, alkaline earth metal iodide or ammonium iodide and hydrogen peroxide.

Claim 19

Process according to Claim 13 or 14, characterised in that the oxidising agents are selected from hydrogen peroxide, periodic acid and its salts, potassium permanganate, sodium hypochlorite, ammonium persulphate, sodium nitrite and the iodide/hydrogen peroxide system.

Claim 20

Process according to any one of Claims 13 to 19, characterised in that the reaction medium is a medium which is non-solvent for the polymer in question, consisting of water or a mixture of water and solvent(s).

Claim 21

Process according to Claim 20, characterised in that the solvent is selected from ethyl alcohol, isopropyl alcohol, tert-butyl alcohol, ethylene glycol monomethyl, monoethyl and monobutyl ethers and ethylene glycol monoethyl ether acetate.

Claim 22

Process according to any one of Claims 13 to 21, characterised in that the indole dye is present in proportions by weight 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.

Claim 23

Cosmetic composition, characterised in that it contains, in a cosmetically acceptable medium, at least one product as defined in any one of Claims 1 to 12 or which is capable of being prepared according to the process defined in any one of Claims 13 to 22.

Claim 24

Composition according to Claim 23, characterised in that it is presented in the form of a lotion, thickened lotion, gel, cream, milk, powder or stick, and that it is optionally packaged as an aerosol.

Claim 25

Composition according to Claim 23, intended for use for makeup of the skin, eyelashes and eyebrows, characterised in that it is presented in anhydrous or aqueous, solid or pasty form.

Claim 26

Composition according to either of Claims 23 or 25, intended for protection of the human epidermis against solar radiation, characterised in that it is presented in the form of a suspension or dispersion in solvents or fats or in the form of an emulsion, ointment, gel, solid stick or aerosol foam.

Claim 27

Composition according to Claim 23, characterised in that it contains fats, organic solvents, silicones, thickeners, emollients, sunscreens, antifoams, moisturisers, fragrances, preservatives, antioxidants, fillers, sequestering agents, treatment agents, propellants, alkalinising or acidifying agents or fats (sic).

Claim 28

Composition according to any one of Claims 23 to 27, characterised in that it contains other pigments permitting variation of the colorations.

Claim 29

Cosmetic application of the composition according to Claim 23 or 26, for protection of the human epidermis.

Claim 30

Application of the composition according to Claim 23, as a makeup product.

Claim 31

Application of the composition according to Claim 23, for the dyeing of human hair.