FR2973690A1 - Artificially coloring the skin comprises applying one or more 1,8-dihydroxynaphthalene derivatives and one or more chemical oxidizing agent, on the surface of the skin - Google Patents

Abstract

Artificially coloring the skin, comprises applying one or more 1,8-dihydroxynaphthalene derivatives (I) and their salts, optical isomers, geometric isomers, tautomers and/or solvates such as hydrates, and one or more chemical oxidizing agent, on the surface of the skin, where (I) and the chemical oxidizing agent are either mixed at the time of use in the same composition A comprising a medium or each present in different composition A1 and a composition A2 comprising a medium, and the compositions A1 and A2 are simultaneously or sequentially applied. Artificially coloring the skin, comprises applying one or more 1,8-dihydroxynaphthalene derivatives of formula (I) and their salts, optical isomers, geometric isomers, tautomers and/or solvates such as hydrates, and one or more chemical oxidizing agent, on the surface of the skin, where (I) and the chemical oxidizing agent are either mixed at the time of use in the same composition A comprising a medium or each present in different composition A1 and a composition A2 comprising a medium, and the compositions A1 and A2 are simultaneously or sequentially applied. Either R1, R6 : H, 1-4C alkyl (functionalized with one or more OH or 1-4C alkoxycarbonyls), carboxylic group, 1-4C alkoxycarbonyl, 1-4C alkylcarbonyl (functionalized with 1-4C alkylcarbonyl or 1-4C alkoxycarbonyls), 1-4C alkoxy or carboxaldehyde; and R2, R5 : H, OH, 1-4C alkyl (functionalized with one or more OH or 1-4C alkoxycarbonyls), carboxylic group, 1-4C alkoxycarbonyl, 1-4C alkylcarbonyl (functionalized with OH), 1-4C alkoxy or carboxaldehyde; or R1R2+C : heterocyclic group (optionally substituted by oxo such as pyrone, preferably 4-pyrone (functionalized with one or two 1-4C alkyl) or ketone group of formula (-C(=O)-C(R1a)=C(R)-O-) (a)); R, R1a : H or 1-4C alkyl; and R3, R4 : H (preferred), OH, 1-4C alkyl (functionalized with one or more OH or 1-4C alkoxycarbonyls), carboxylic group, 1-4C alkoxycarbonyl or 1-4C alkylcarbonyl (functionalized with 1-4C alkylcarbonyl or 1-4C alkoxycarbonyls). [Image].

Description

The present invention relates to a method for artificially coloring the skin, comprising at least the application on the surface of the skin, and a method for the artificial dyeing of the skin, comprising at least the application on the surface of the skin. skin of: - i) one or more 1,8-dihydroxynaphthalene derivative (s) of formula (I) which will be defined later in detail; - ii) one or more chemical oxidizing agent (s); it being understood that: the 1,8-dihydroxynaphthalene derivative (s) of formula (I) and the oxidizing agent (s) are either mixed at the time of use in the same composition A comprising a cosmetically acceptable medium is contained respectively in an AI composition and a different A2 composition each comprising a cosmetically acceptable medium; said compositions AI and A2 being applied simultaneously or sequentially.

It is common for persons with pigmented spots, or dark circles, to correct these cutaneous dyschromias and use for this purpose cosmetic or dermatological compositions which make it possible to homogenize the complexion.

It is also common for people with fair skin to darken their skin color to give it a more aesthetically pleasing "halftone" appearance, such as after sun or UV exposure.

For these purposes, it is known to use for the purpose of immediate homogenization of the complexion covering products which although concealing the skin imperfections 30 have the major disadvantage of masking the natural appearance of the skin (feeling mask).

It is also known to use products containing interferential pigments such as nacres which, although they can hide skin imperfections, have the major disadvantage of giving the skin a shiny and unnatural appearance.

It is also known to use a mixture of lipophilic dyes consisting of at least one carotenoid and at least one lipophilic green dye (FR2939036 (A1)), which makes it possible to obtain a uniform complexion and a good-looking effect. has the disadvantage of being colored.

Finally, it is known to use self-tanning products which are based on carbonyl derivatives such as dihydroxyacetone (DHA) allowing, by interaction with the free amine functions of the skin, in particular the amino acids, peptides and proteins of the skin, the formation of colorful products. These products, in particular colorless DHA-based products, by imparting a halftone appearance and by gradually generating the color in the manner of a natural tan, make it possible to conceal skin imperfections and improve the aesthetics of the skin. Unfortunately, this is only possible on light skin. On dark skin, self-tanners like DHA do not produce an adequate complexion. Indeed, DHA is characterized by an orange-yellow color does not allow sufficient effect to homogenize the complexion on dark skin. This would require a molecule giving the skin a browner shade, that is to say characterized by a red component greater than DHA. In addition, another disadvantage of self-tanners, such as DHA, is the slowness with which the color develops: it takes several hours (usually 3 to 5 hours) to reveal the color.

Thus, there is still a need to find a new method of non-covering artificial coloring of the skin which makes it possible to quickly give it a homogeneous tint and a "good-looking" effect which can correct the 30 cutaneous dyschromias without the disadvantages stated above without masking the natural appearance of the skin, and whatever the type of light or dark skin, from a composition not or little color.

This object is achieved by the present invention which relates to a method of artificially coloring the skin comprising at least the application on the surface of the skin of - i) one or more derivative (s) of 1,8-dihydroxynaphthalene of formula (I) OH OH 3 (I) as well as their salts, their optical isomers, geometric, their tautomeric forms, and / or their solvates such as hydrates; in which: R 1 and R 6 represent, independently of each other: a hydrogen atom, a C 1 -C 4 alkyl radical that can be functionalized with one or more hydroxyl, C 1 -C 4 alkoxycarbonyl radicals, a radical carboxylic acid -O2H, - a (C1-C4) alkoxycarbonyl radical, - a (C1-C4) alkylcarbonyl radical which can be functionalized with a (C1-C4) alkylcarbonyl radical, a (C1-C4) alkoxycarbonyl radical, a C 1 -C 4 alkoxy radical; a carboxaldehyde radical -CHO, R 2 and R 5 represent, independently of one another: a hydrogen atom; a hydroxyl radical; a C 1 -C 4 alkyl radical that can be functionalized; by one or more hydroxyl radicals, (C 1 -C 4) alkoxycarbonyl radicals, a carboxylic radical -CO 2 H, a (C 1 -C 4) alkoxycarbonyl radical, a (C 1 -C 4) alkylcarbonyl radical which can be functionalized with a radical hydroxyl - a C1-C4 alkoxy radical, - a carboxaldehyde radical -CHO, R3 and R4 represent indi- dangling from each other: - a hydrogen atom, - a hydroxyl radical, - a C 1 -C 4 alkyl radical that can be functionalized with one or more hydroxyl radicals, C 1 -C 4 alkoxycarbonyl radicals, - a carboxylic radical -OO 2 H a (C1-C4) alkoxycarbonyl radical; a (C1-C4) alkylcarbonyl radical which can be functionalized with a (C1-C4) alkylcarbonyl radical or a (C1-C4) alkoxycarbonyl radical; R 1 and R 2 may form together with the carbon atoms to which they are attached a heterocyclic optionally substituted with an oxo group such as pyrone, particularly 4-pyrone, which may be functionalized with one or two (to) C 1 -C 4 alkyl radicals; with R and R ', identical or different, representing a hydrogen atom or a C1-C4 alkyl radical; preferably R and R 'represent a hydrogen atom or R' represents a hydrogen atom and R represents a C1-C4 alkyl radical; and ii) one or more chemical oxidizing agent (s); It being understood that: the 1,8-dihydroxynaphthalene derivative (s) of formula (I) and the oxidizing agent (s) are either mixed at the time of use in the same composition A comprising a cosmetically acceptable medium is contained respectively in an AI composition and a different A2 composition each comprising a cosmetically acceptable medium; said compositions AI and A2 being applied simultaneously or sequentially.

Within the meaning of the present invention, the term "artificial coloring of the skin" will be understood to mean a durable, non-covering coloring (ie not having a tendency to opacify the skin) and which is not eliminated at all. water or with a solvent, and which is resistant to both rubbing and washing with a solution containing surfactants. Such durable coloration is therefore distinguished from the superficial and temporary coloring provided for example by a makeup product. For the purposes of the present invention, and unless a different indication is given:

Within the meaning of the present invention, the term "physiologically acceptable medium" is understood to mean a carrier compatible with the skin, the nails, the lips, the eyelashes and the eyebrows, which has a pleasant color, odor and feel and which generates no unacceptable discomfort (tingling, tightness, redness), likely to divert the consumer to use this composition comprising such a support. The alkyl radicals are saturated, linear or branched, generally C 1 -C 4, hydrocarbon radicals, such as methyl, ethyl, propyl and butyl.

The alkoxy radicals are alkyl-oxy radicals with alkyl as defined above, preferably C1-C4, such as methoxy, ethoxy, propoxy and butoxy.

The heterocycle optionally substituted with an oxo group is a heterocycle fused to the 1,8-dihydroxynaphthalene ring via the radicals R 1 and R 2; said heterocycle comprising from 5 to 7 members, from one to three heteroatoms selected from oxygen, sulfur or nitrogen, and which may further comprise an oxo or carbonyl group, and an unsaturation preferentially conjugated with the group oxo.

Other features, aspects and advantages of the present invention will be apparent from the following detailed description.

1,8-Dihydroxynaphthalene derivative of formula (I): In the definition of formula (I): the alkyl radicals are saturated, linear or branched, generally C 1 -C 4, hydrocarbon radicals, such as methyl, ethyl, propyl and butyl.

the alkoxy radicals are alkyl-oxy radicals with alkyl as defined above, preferably C1-C4, such as methoxy, ethoxy, propoxy and butoxy. i0 - the heterocycle optionally substituted with an oxo group is a heterocycle fused to the 1,8-dihydroxynaphthalene ring via the radicals R1 and R2; said 5- to 7-membered heterocycle having one to three heteroatoms selected from oxygen, sulfur or nitrogen, and which may further include an oxo or carbonyl group, and unsaturation preferably conjugated with the group oxo.

A particular embodiment of the invention relates to 1,8-dihydroxynaphthalene derivatives of formula (I) for which R 1 and R 6 represent, independently of each other: a hydrogen atom, a C 1 -C 4 alkyl radical, a carboxylic radical -OO 2 H, a (C 1 -C 4) alkoxycarbonyl radical, a C 1 -C 4 alkylcarbonyl radical which can be functionalized with a (C 1 -C 4) alkylcarbonyl radical or a (C 1 -C 4) alkoxy radical; carbonyl; more particularly R1 and R6 independently of one another represent: - a hydrogen atom, - a C1-C4 alkyl radical, 3o - a (C1-C4) alkoxycarbonyl radical, - a (C1-C4) alkylcarbonyl radical may be functionalized with a (C1-C4) alkylcarbonyl radical, a (C1-C4) alkoxycarbonyl radical.

According to another particular embodiment of the invention, the 1,8-dihydroxynaphthalene derivatives of formula (I) are such that R2, and R5 represent independently of each other: a hydrogen atom, a hydroxyl radical, a C1-C4 alkyl radical which can be functionalized with a (C1-C4) alkoxycarbonyl radical; - (C1-C4) alkoxycarbonyl radical; - a C1-C4alkoxy radical. Another particular embodiment of the invention concerns 1,8-dihydroxynaphthalene derivatives of formula (I) for which R3 and R4 represent a hydrogen atom.

More particularly, the compounds according to the invention are chosen from the following: (1) OH OH 1,8-Dihydroxynaphthalene extracted from ascomycete-like fungi (2) OH OH 1- (1,8-Dihydroxy-3) methyl-naphthalen-2-yl) ethanone extracted from: Maesopsis eminii, Dianella laevis, Dianella nigra, Rumex spp. (3) OH OH O 1- (1,8-Dihydroxy-3,6-dimethyl-naphthalen-2-yl) -ethanone (4) OH-2,7-Dimethyl-naphthalene-1,8-diol (5) OH O, 8-Dihydroxy-3-methoxycarbonylmethyl-OH O1 1,8-Dihydroxy-3-methoxycarbonylmethylnaphthalene-2-carboxylic acid methyl ester OO (6) OH-1,8-Dihydroxy-3-methoxycarbonylmethyl O-naphthalene-2,6-dicarboxylic acid 6-ethyl ester 2-methyl ester (7) OH OH OH 1- (1,6,8-Trihydroxy-3-methyl-naphthalen-2-yl) -ethanone : Aphis spiraecola (8) OH OH OO 1- (1,6,8-Trihydroxy-3-methyl-naphthalen-2-yl) -butane-1,3-dione OH OH OO 9 HO ® ~ 0 3-Oxo (3-Hydroxymethyl-naphthalene-1,8-diol (3) -3- (1,6,8-trihydroxy-3-methyl-naphthalen-2-yl) -propionic acid methyl ester (10) OH OH OH 3-Methyl-naphthalene-1,8-dol extracted from: Diospyros mollis (12) OH 1- (4,5-Dihydroxy-7-methoxy-naphthalen-2-yl) -2-hydroxypropan 1 -one extract of: Chaetomium atrobrunneum OH OH (13) δe 4,5-Dihydroxy-naphthalene-2-carbaldehyde (14) OH OH ZZ O 6-Acetyl-4,5-dihydroxy-7-methyl-naphthalene-OH 2 carboxylic acid (15) OH OH 1- (1,8-Dihydroxy-3-hydroxymethyl-naphthalen-2-yl) ) -ethanone (16) OH OH O 1- (1,8-Dihydroxy-naphthalen-2-yl) -ethanone extracted from: Rhamnus frangula (17) O-OH OH 1 - (1,6,8-Trihydroxy-3) Methyl-naphth-alen-2-yl) -ethanone (18) 5,6,8-Trihydroxy-2-methyl-benzo [g] chromen-OH I-4-one extracted from: Cassia tora (19) 8,6-Dihydroxy-8-methoxy-2-methylbenzo [g] chromen-4-one extracted from Fusarium culmorum, Senna obliqua, Comantheria briareus (20); 6-Dihydroxy-8-methoxy-2,9-dimethylbenzo [g] chromen-4-one extracted from Cassia quinquangulata, Senna obliqua. (21) OH OH 1- (1,6,8-Trihydroxy-3-methyl-naphthalen-2-yl) -ethanone 6-methyl ether extracted from: Cassia tora, Rhamnus nakaharai. 1,3,8-Trihydroxynaphthalene extracted from: Lachnellula sp., Verticillium dahliae, Alternaria sp. Stamm 6588. Compounds (1) to (22) as well as their optical isomers, geometric, their tautomers, their hydrates and their addition salts with an organic or mineral base. The preferred compounds of formula (I) are the compounds (1), (2), (3), (4), (5), (6), (7), (8), (9), (11) and (21). Even more preferred compounds are compounds (1), (2) and (11).

The 1,8-dihydroxynaphthalene derivatives of formula (I) used in the invention may be natural, synthetic and / or commercial. The compounds of formula (I) can be synthesized by the synthetic routes described in the literature. As such, mention may be made in particular of the following references: 206, - Journal of Physical Chemistry A 2007, 111 (2), 345-351, - Journal of Organic Chemistry 1990, 55 (5), 1611-1623, Journal of the Chemical Society, Chemical Communication 1979, 206, Journal of the Chemical Society, Chemical Communication 1979, 206, 1165, The salts of 1,8-dihydroxynaphthalene derivatives of formula (I) according to the invention may be salts acids or bases. The acids can be inorganic or organic. Preferably the acid is hydrochloric acid which leads to chlorides.

The bases can be mineral or organic. Especially the bases are alkali hydroxides such as sodium hydroxide which leads to sodium salts. According to a particular embodiment of the invention, the composition comprises one or more 1,8-dihydroxynaphthalene derivative (s) of synthetic formula (I) which does not exist in nature.

According to another preferred embodiment of the invention, the 1,8-dihydroxynaphthalene derivative (s) of formula (I) according to the invention are natural. OH OH (22) OH - Australian Journal of Chemistry 1988, 41 (7), 1087, 20 - Journal of the American Chemical Society 1988, 110 (18), 6172, - Synthetic Communication 2007, 37 (18), 3041.

According to one embodiment, the 1,8-dihydroxynaphthalene derivatives of formula (I) are natural extracts of animals, bacteria, fungi, algae, plants used in their entirety or partially. Preferably, the 1,8-dihydroxynaphthalene derivative (s) of formula (I) of the invention are derived from a fungus such as Daldinia concentrica, of fruit such as Diospyros Mollis. These natural 1,8-dihydroxynaphthalene derivatives of formula (I) are obtained from extracts whose purification can be carried out by simple extraction without chemical treatment or chemical reaction.

Mixtures of extracts can also be used.

According to a preferred mode, the 1,8-dihydroxynaphthalene derivative (s) of formula (I) are only natural extracts. The natural extracts according to the invention can be in the form of powders or liquids. The extracts of the invention are preferably in the form of powders.

According to the invention, the synthetic 1,8-dihydroxynaphthalene derivative (s) of formula (I), natural (s), and / or the natural extract (s) used ( s) in the composition according to the invention represents (s) preferably from 0.001% to 20% by weight of the total weight of the composition (s) containing the 1,8-dihydroxynaphthalene derivative (s) of formula (I) or or extracts. With regard to the pure 1,8-dihydroxynaphthalene derivatives of formula (I), the content in the composition or compositions containing them is preferably between 0.001 and 20% by weight of each of these compositions.

With regard to the extracts, the content in the composition or compositions containing the extracts as such is preferably between 0.001 and 20% by weight of each of these compositions. Oxidizing agents, oxidation catalysts, mordants The dyeing process of the invention involves at least one chemical oxidizing agent.

The term "chemical oxidizing agent" means an oxidizing agent other than oxygen in the air (O 2).

This or these agent (s) are preferably chosen from - hypochlorites such as alkali metal or alkaline earth metal hypochlorites such as sodium hypochlorite; peroxides such as hydrogen peroxide; urea peroxide, especially hydrogen peroxide, alkali metal bromates, persalts such as perborates, peracids, especially magnesium monoperphthalate; molybdates such as sodium molybdate; - periodic acid and its water-soluble salts and derivatives; - dichromates such as sodium or potassium dichromates; cupric halides such as cupric chloride, cupric bromide, alkali metal or alkaline earth metal ferricyanides such as potassium ferricyanide; or - the hydrogen peroxide generator systems such as: the polymer complexes which can release hydrogen peroxide, such as polyvinylpyrrolidone / H 2 O 2 in particular being in the form of powders and the other complexes polymers disclosed in US 5,008,093; US 3,376,110; US 5,183,901; . peroxides of metals generating in water hydrogen peroxide such as calcium peroxide, magnesium peroxide; . oxidases producing hydrogen peroxide in the presence of a suitable substrate (for example glucose in the case of glucose oxidase or uric acid with uricase); as well as the enzymes among which there may be mentioned peroxidases, 2-electron oxidoreductases such as uricases and 4-electron oxygenases such as laccases.

The uses of hydrogen peroxide and hypochlorites are particularly preferred. And more particularly, use will be made of an oxidizing agent chosen from hypochlorites such as alkali metal or alkaline earth metal hypochlorites and more particularly sodium hypochlorite

According to another variant, the process further involves an oxidation catalyst. By way of example, this catalyst may be chosen from the manganese (Mn) salts of zinc (Zn), iron (Fe) and copper (Cu).

Alkalinizing agents According to one particular form of the invention, the dyeing process according to the invention additionally involves at least one alkalinizing agent. The basifying agent is preferably chosen from alkanolamines such as mono-, di- and triethanolamines, alkali carbonate salts, guanidine, imidazole, sodium, potassium or calcium hydroxides and arginine and the like. compounds of the following formula (II): ## STR2 ## wherein: W is a propylene residue optionally substituted by a hydroxyl group or a C 1 -C 4 alkyl radical; Ra, Rb, Rc and Rd, which may be identical or different, represent a hydrogen atom, a C1-C4 alkyl radical or a C1-C4 hydroxyalkyl radical.

More particularly, the alkalinizing agent (s) is (are) chosen from ethanolamine, carbonate salts, guanidine, imidazole, calcium hydroxide and arginine.

The basifying agent will preferably be present in the composition comprising the 1,8-dihydroxynaphthalene derivative (s) of formula (I).

According to another particular form of the invention, the dyeing process according to the invention does not involve any basifying agent. One object of the invention is a method of artificially coloring the skin by application to the skin surface of: - i) one or more 1,8-dihydroxynaphthalene derivative (s) of the formula (I) which will be defined later in detail; - ii) one or more chemical oxidizing agent (s); the 1,8-dihydroxynaphthalene derivative (s) of formula (I) and the oxidizing agent (s) are either mixed at the time of use in the same composition A comprising a cosmetically acceptable medium either are contained respectively in a composition AI and a different composition A2 each comprising a cosmetically acceptable medium; said compositions AI and A2 being applied simultaneously or sequentially. According to a preferred embodiment of the dyeing process of the invention the ingredients i) and ii) are applied in one step. In which case, preferably, the ingredients i) and ii) are together in a cosmetic extemporaneous composition A prepared at the time of use which is then applied to the skin.

According to another particular embodiment of the dyeing process of the invention, the ingredients i) and ii) are applied sequentially. In which case preferably the ingredient i) is the composition AI comprising a cosmetically acceptable medium and the ingredient ii) is in the other composition A2 comprising a cosmetically acceptable medium.

According to a first advantageous variant of the invention, one of the cosmetic compositions AI comprising the ingredient i) is applied in a first step on the skin and then in a second step the other cosmetic composition A2 comprising the ingredient ii is applied. ).

According to another variant of the invention, one of the cosmetic compositions A2 comprising ingredient ii) is applied in a first step on the skin and then, in a second step, the other cosmetic composition AI comprising the ingredient i) is applied. .

According to another preferred embodiment of the staining method, the extemporaneous composition A or the composition AI containing the ingredient i), the 1,8-dihydroxynaphthalene derivative (s) of the formula (I) as defined above also contains an oxidation catalyst. By way of example, this catalyst may be manganese gluconate or zinc gluconate. The exposure time for the oxidation to be carried out in the air is between 3 and 120 minutes. Preferably, after application of the composition containing the 1,8-dihydroxynaphthalene derivatives of formula (I), the composition is left to act for 10 to 60 minutes. The application can be made in one or more steps, in oxidizing and basic conditions.

A particular variant of the invention consists of a dyeing process in which the skin is treated with the ingredient i) one or more derivative (s) of 1,8-dihydroxynaphthalene of formula (I) as defined ( s) previously; ingredient 40 ii) one or more oxidizing agents; optionally the ingredient iii) one or more oxidation catalyst (s) and optionally the ingredient and optionally the ingredient iv) one or more agent (s) alkalinizing (s) in different steps.

Whatever the mode of application, the application temperature is generally between room temperature and 50 ° C and more particularly between 15 ° C and 45 ° C. Thus, it is advantageous, after application of the composition or compositions comprising the ingredients i) to iv) as defined above to subject the skin to heat treatment by heating at a temperature of between 30 and 50 ° C. In practice, this operation can be carried out by means of an infrared dispenser and other conventional heating devices.

A particular embodiment of the invention relates to a dyeing process which is carried out at room temperature (25 ° C).

In all the particular modes and variants of the processes described above, the compositions mentioned are ready-to-use compositions which may result from the extemporaneous mixing of two or more compositions and in particular of compositions present in skin coloration kits.

Dosage Forms The compositions of the invention may be in any form suitable for topical application, especially in the form of an aqueous or aqueous-alcoholic lotion, aqueous gels, in the form of emulsions obtained by dispersion of a fatty phase (called also oily phase) in an aqueous phase (O / W) or conversely (W / O) or multiple emulsions (for example E / H / E or H / E / H or H / H / E). They may be more or less fluid and have the appearance of a white or colored cream, an ointment, a milk, a lotion, a serum, a paste and possibly be packaged in aerosol and be in the form of foam or spray. These compositions are prepared according to the usual methods. The composition or compositions of the dyeing process according to the invention may also contain various adjuvants conventionally used in skin-coloring compositions, such as organic solvents, surfactants, polymers, mineral thickeners. or organic, and in particular anionic, nonionic and amphoteric polymeric associative thickeners, antioxidants, penetrating agents, sequestering agents, fragrances, buffers, dispersing agents, conditioning agents, film-forming agents, ceramides, preservatives, opacifying agents, organic or inorganic UV filters, self-tanning agents, dyestuffs such as direct dyes, pigments, nacres. Said adjuvants are preferably chosen from surfactants such as anionic, nonionic surfactants or mixtures thereof and inorganic or organic thickeners. The adjuvants above are generally present in an amount for each of them between 0.01 and 40% by weight relative to the weight of the composition, preferably between 0.1 and 20% by weight relative to the weight of the composition.

Of course, those skilled in the art will take care to choose this or these optional complementary compounds in such a way that the advantageous properties intrinsically attached to the composition in accordance with the invention are not, or not substantially, impaired by the one or more additions considered.

Concrete but non-limiting examples illustrating the invention will now be given.

Example of a process for coloring the skin:

100 mg of 1,8-dihydroxynaphthalene is dissolved in 1 ml of ethanol and 1 ml of water. 20 μl of this mixture are applied to 1 cm 2 of skin, then 20 μl of aqueous sodium hypochlorite (bleach with 2.5% of active chlorine) at room temperature. The coloring acts for 1 hour, then the skin is washed with water. Staining of the persistent brown skin is observed.

Claims (12)

REVENDICATIONS1. A method of artificially coloring the skin comprising at least the application on the skin surface of - i) one or more 1,8-dihydroxynaphthalene derivative (s) of the formula (I) OH (I) and their salts their optical, geometric isomers, their tautomers, and / or their solvates such as hydrates; in which: R 1 and R 6 represent independently of each other: a hydrogen atom, a C 1 -C 4 alkyl radical that can be functionalized with one or more hydroxyl radicals, C 1 -C 4 alkoxycarbonyl radicals, carboxylic acid -O2H, - a (C1-C4) alkoxycarbonyl radical, - a (C1-C4) alkylcarbonyl radical which can be functionalized with a (C1-C4) alkylcarbonyl radical, a (C1-C4) alkoxycarbonyl radical, a C 1 -C 4 alkoxy radical; a carboxaldehyde radical -CHO 2, R 2 and R 5 represent, independently of one another: a hydrogen atom; a hydroxyl radical; a C 1 -C 4 alkyl radical that can be functionalized; by one or more hydroxyl radicals, (C 1 -C 4) alkoxycarbonyls, a carboxylic radical -CO 2 H, a (C 1 -C 4) alkoxycarbonyl radical, a (C 1 -C 4) alkylcarbonyl radical which can be functionalized with a radical hydroxyl - a C1-C4 alkoxy radical; - a carboxaldehyde radical -CHO, R3 and R4 represent independant each of the following: - a hydrogen atom, - a hydroxyl radical, - a C1-C4 alkyl radical which can be functionalized with one or more hydroxyl, (C1-C4) alkoxycarbonyl radicals, - a carboxylic radical - OO2H - a (C1-C4) alkoxycarbonyl radical; - a (C1-C4) alkylcarbonyl radical which can be functionalized with a (C1-C4) alkylcarbonyl radical or a (C1-C4) alkoxycarbonyl radical; R 1 and R 2 may form together with the carbon atoms to which they are attached a heterocyclic optionally substituted by an oxo group such as pyrone, particularly 4-pyrone, which may be functionalized by one or two (C 1 -C 4) alkyl radicals; with R and R ', identical or different, representing a hydrogen atom or a C1-C4 alkyl radical; preferably R and R 'represent a hydrogen atom or R' represents a hydrogen atom and R represents a C1-C4 alkyl radical; and ii) one or more chemical oxidizing agent (s); it being understood that: the 1,8-dihydroxynaphthalene derivative (s) of formula (I) and the oxidizing agent (s) are either mixed at the time of use in the same composition A comprising a cosmetically acceptable medium are respectively contained in a composition AI and a different composition A2 each comprising a cosmetically acceptable medium; said compositions AI and A2 being applied simultaneously or sequentially. 30 2. Process according to claim 1, wherein the 1,8-dihydroxynaphthalene derivatives of formula (I) are chosen from those for which RI and R6 represent independently of each other: a hydrogen atom, a radical C1-C4 alkyl, - a carboxylic radical -OO2H, - a (C1-C4) alkoxycarbonyl radical, - a (C1-C4) alkylcarbonyl radical which can be functionalized with a (C1-C4) alkylcarbonyl radical, a radical (C1-C4) alkoxycarbonyl; more particularly, R 1 and R 6 represent independently of each other: a hydrogen atom, a C 1 -C 4 alkyl radical, a C 1 -C 4 alkoxycarbonyl radical, a C 1 -C 4 alkylcarbonyl radical; which can be functionalized with a (C1-C4) alkylcarbonyl radical, a (C1-C4) alkoxycarbonyl radical. 3. Process according to claim 1 or 2, wherein the 1,8-dihydroxynaphthalene derivatives of formula (I) are chosen from those for which R 2 and R 5 represent independently of each other: a hydrogen atom, a hydroxyl radical; - a C1-C4 alkyl radical which can be functionalized with a (C1-C4) alkoxycarbonyl radical; a (C1-C4) alkoxycarbonyl radical; a (C1-C4) alkoxy radical; 4. Process according to any one of claims 1 to 3, wherein the 1,8-dihydroxynaphthalene derivatives of formula (I) are chosen from those for which R3 and R4 represent a hydrogen atom. 5. Process according to any one of claims 1 to 4, wherein the 1,8-dihydroxynaphthalene derivatives of formula (I) are chosen from (1) OH ZZ 1,8-Dihydroxynaphthalene OH extracted from ascomycete-type fungi (2). ) O (1- (1,8-Dihydroxy-3-methyl-naphthalen-2-yl) -ethanone extracted from: Maesopsis eminii, Dianella laevis, Dianella nigra, Rumex spp. (3) OH OH O 1- (1,8-Dihydroxy-3,6-dimethyl-naphthalen-2-yl) -ethanone (4) OH-2,7-Dimethyl-naphthalene-1,8-diol (5) OH OH 1,8-Dihydroxy-3-methoxycarbonylmethyl-0.8-dihydroxy-3-methoxycarbonylmethyl-naphthalene-2-carboxylic acid methyl ester (6) OH-OH-1,8-Dihydroxy-3-methoxycarbonylmethyl-O naphthalene-2,6-dicarboxylic acid 6-ethyl ester 2-methyl ester (7) OH OH OH 1- (1, 6,8-Trihydroxy-3-methyl-naphthalen-2-yl) -ethanone Extract from: Aphis spiraecola (8) HO OH OH OO 1 - (1, 6,8-Trihydroxy-3-methyl-naphthalen-2-yl) -butane-1,3-dione OH OH OZZ 3-Oxo-3- (1,6,8-trihydroxy) 3-Methyl-naphthalene-1,8-diol extract from: Diospyros mollis (12) OH 1- (4,5-Dihydroxy-7-methoxy-naphthalo-2-yl) -2-hydroxy-propan-1-one extracted from: Chaetomium atrobrunneum (13) OH OH 4,5-Dihydroxy-naphthalene-2-carbaldehyde (14) OH 6 -O-acetyl-4,5-dihydroxy-7-methyl-naphthalene-2-carboxylic acid (15) OH OH O 1 - (1, 8-Dihydroxy-3-hydroxymethyl-naphthalen-2-yl) -ethanone (16) OH OH 1- (1,8-Dihydroxy-naphthalen-2-yl) -ethanone extracted from: Rhamnus frangula (17) HO OH OH 1- (1,6,8-Trihydroxy-3-methyl-naphth-alen-2-yl) -ethanone (18) HO OH® ~ 5,6,8-Trihydroxy-2-methyl-b enzo [g] chromen-OH I 4-one extracted from: Cassia tora (19) ~ o OH OH o 5,6-Dihydroxy-8-methoxy-2-methyl-benzo [g] chromen-4-one extracted from Fusarium culmorum, Senna obliqua, Comantheria briareus (20) 5,6-Dihydroxy-8-methoxy-2,9-dimethylbenzo [g] chromen-4-one extract of Cassia quinquangulata, Senna obliqua. (21) OH 1- (1,6,8-Trihydroxy-3-methyl-naphthalen-2-yl) -ethanone 6-methyl ether extracted from: Cassia tora, Rhamnus nakaharai. (22) OH OH OH 1,3,8-Trihydroxynaphthalene extracted from: Lachnellula sp., Verticillium dahliae, Alternaria sp. Stamm 6588. as well as their optical, geometric isomers, their tautomers, their hydrates and their addition salts to an organic or mineral base. 6. Process according to claim 5, wherein the 1,8-dihydroxynaphthalene derivatives of formula (I) are chosen from compounds (1), (2), (3), (4), (5), (6) , (7), (8), (9), (11) and (21) and more preferably from the compounds (1), (2) and (11). 7. Process according to any one of Claims 1 to 6, in which the chemical oxidizing agent (s) is (are) chosen from: hypochlorites; peroxides, alkali metal bromates, persalts, peracids; - molybdates - periodic acid and its water-soluble salts and derivatives; - the dichromates; - cupric halides, - ferricyanides of alkali or alkaline-earth metal 5 - systems (s) generator (s) of hydrogen peroxide. The process according to claim 7, wherein the chemical oxidizing agent (s) is (are) selected from hypochlorites such as alkali metal or alkaline earth metal hypochlorites; particularly the chemical oxidizing agent is sodium hypochlorite. 9. The method of dyeing according to any one of claims 1 to 8, wherein is further used at least one basifying agent; said basifying agent being preferably present in extemporaneous composition A or composition AI comprising the 1,8-dihydroxynaphthalene derivative (s) of formula (I). The staining method according to claim 9, wherein the basifying agent is selected from alkanolamines such as mono-, di- and triethanolamines, alkali carbonate salts, guanidine, imidazole, hydroxides of sodium, potassium or calcium and arginine and compounds of formula (II): embedded image where: W is a propylene residue optionally substituted by a hydroxy group or a C 1 -C 6 alkyl radical; C4; Ra, Rb, Rc and Rd, which may be identical or different, represent a hydrogen atom, a C1-C4 alkyl radical or a C1-C4 hydroxyalkyl radical. 3o 11. The method of dyeing according to any one of claims 1 to 8 which does not implement alkalinizing agent. 12. A dyeing process according to any one of claims 1 to 10 which uses one or more oxidation catalyst (s); said catalyst (s) being preferably present in extemporaneous composition A or in composition AI comprising the 1,8-dihydroxynaphthalene derivative (s) of formula (I) and are chosen ( s) among the salts of Manganese (Mn) Zinc (Zn), Iron (Fe), Copper (Cu). i0