WO2004066968A2

WO2004066968A2 - Use of conductive polythiophenes for the treatment of human keratin materials

Info

Publication number: WO2004066968A2
Application number: PCT/EP2004/002029
Authority: WO
Inventors: Nathalie Mougin; Gwenaëlle JEGOU; Henri Samain
Original assignee: L'oréal
Priority date: 2003-01-31
Filing date: 2004-01-30
Publication date: 2004-08-12
Also published as: WO2004066968A3

Abstract

The invention relates to the use of a composition which comprises, in a cosmetically acceptable medium, at least one particular conductive polythiophene which is in a soluble or dispersible form in said medium, as an agent for imparting an optical effect to human keratin materials and more particularly to human keratin fibres. Another subject of the invention is the use of compositions comprising a polythiophene which absorbs in the visible spectrum, to colour said fibres.

Description

USE OF CONDUCTIVE POLYTHIOPHENES FOR THE TREATMENT OF HUMAN KERATIN MATERIALS

The invention relates to the use of compositions which comprise, in a cosmetically acceptable medium, at least one conductive polythiophene as an agent for imparting an optical effect to human keratin materials and more particularly to fibres. Furthermore, if said polythiophene absorbs in the visible, the composition comprising it is used as an agent for colouring said materials.

The invention further relates to a composition comprising said polythiophene.

Products for imparting shiny effects to the hair are known.

Such products contain molecules or polymers in the solubilized state in a cosmetic solvent, in the form of an emulsion or dispersion.

However, these products still do not impart the desired shine to the hair.

To obtain a shiny effect on the hair, it is known to use compositions rich in lubricating hydrophobic substances such as organic oils or waxes, or silicones. However, once again, the shiny effect obtained lacks intensity and generally gives the hair an artificial appearance .

Moreover, once applied to the hair, such compositions have the disadvantage of giving the hair a greasy or sticky feel, which is not satisfactory. There is therefore a need for compositions that are capable of imparting an intense and natural shine to human keratin materials, more particularly fibres and advantageously hair, without exhibiting the disadvantages mentioned above. Moreover, to obtain particularly attractive effects, it can be of value to impart a shine coupled with a colouration.

Now, it has been found, totally unexpectedly and surprisingly, that the use of conductive polythiophenes makes it possible to impart to the whole head of hair a uniform optical effect, and more particularly a shine, which is substantially more intense, more natural and more attractive than when using the means of the prior art.

Moreover, if said conductive polythiophenes absorb in the visible spectrum, an optical effect, such as a shine, and colour are obtained simultaneously.

Finally, the hair advantageously has a soft and pleasant feel.

Thus a first subject of the present invention is the use, as an agent for imparting an optical effect to human keratin materials and more particularly to human keratin fibres, of a composition which comprises, in a cosmetically acceptable medium, at least one conductive polythiophene that is present in a soluble or dispersible form in said medium and comprises at least one repeat unit of formulae (I) to (III) below:

in which formulae: the radicals Ri to R, which are identical or different, are selected from the group comprising hydrogen; a radical -R, -OR, -COOR or -OCOR, where R is a linear or branched Cι-C₂n-alkyl radical; a halogen atom; a nitro radical; a cyano radical; an alkylcyano radical; and a solubilizing group, it being understood that at least one radical Ri to R is a solubilizing group; and

Z is -CH=CH- or -C≡C-. A second subject of the invention consists of the use, as an agent for colouring human keratin materials and more particularly human keratin fibres, of a composition which comprises, in a cosmetically acceptable medium, at least one conductive polythiophene that absorbs light in the visible spectrum, is present in a soluble or dispersible form in said medium and comprises at least one repeat unit of formulae (I) to (III) above.

The invention further relates to a dyeing composition for human keratin fibres and more particularly hair, said composition comprising, in a cosmetically acceptable medium, at least one conductive polymer that is present in a soluble or dispersible form in said medium, absorbs in the visible spectrum and comprises at least one repeat unit of formulae (I) to (III) .

However, other characteristics, features, subjects and advantages of the invention will become more clearly apparent from the description and Example which follow.

Unless indicated otherwise, when ranges are indicated below as being between two values, these two values are included.

In terms of the present invention, optical effect' embraces shiny, metallic, colour, goniochromatic, shimmering, fluorescent, thermochromic and electrochromic effects.

More particularly, shine is understood as meaning the luminous intensity reflected at an angle α when the lock of hair is illuminated at an angle -α. The angle α conventionally used to measure this specular reflection, or shine, is equal to 20°. This imparted shine can be measured using a gloss meter, as described e.g. in AFNOR standard ISO 2813 - 1994 (August 1994, amended February 1997).

Conductive polythiophenes

The conductive polythiophene used within the framework of the invention has a molecular structure in which the monomer (s) have highly delocalized electrons and whose arrangement in the polymer backbone enables the π orbitals to overlap. The effect of this chemical characteristic is a phenomenon of electrical conduction which may or may not be accompanied by a phenomenon of absorption in the UV-visible spectrum or in the infrared.

When it is indicated in the text that the conductive polythiophene absorbs in the visible, this means that the polymer has a non-zero absorbance in the wavelength range from 400 to 800 nm, even if the absorption maxima of the polymer are situated outside this range.

The conductive polymers used within the framework of the present invention are conductive polymers that are soluble or dispersible in the cosmetic medium appropriate to the application.

The polymer is said to be soluble in the medium if it forms an isotropic clear liquid at 25°C in a medium comprising water or a water/solvent mixture, this condition being obtained over all or part of a concentration range between 0.01 and 50% by weight of conductive polymer.

The polymer is said to be dispersible in a medium comprising water or a water/solvent mixture if, at 0.01% by weight and at 25°C, it forms a stable suspension of fine, generally spherical particles. The mean size of the particles constituting said dispersion is below 1 μm and, more generally, varies between 5 and 400 nm and preferably from 10 to 250 nm. These particle sizes are measured by light scattering.

Preferably, the conductive polymers used within the framework of the present invention are conductive polymers that are soluble or dispersible in an aqueous medium, advantageously water.

It should be pointed out that, advantageously, these polymers do not require the use of a dispersant. According to a preferred embodiment, the conductive polymers used within the framework of the present invention are soluble in an aqueous medium, advantageously water.

Furthermore, the polymers advantageously have a conductivity of between 10^~5 and 5.10⁵ siemens/cm, more particularly of between 10^~3 and 10⁵ siemens/cm and preferably of between 10^_1 and 10⁴ siemens/cm.

The conductivity is measured with the aid of a current generator (RM2 Test Unit marketed by Jandel) equipped with a universal four-point probe (marketed by Jandel) . The four points, which are aligned and separated by the same spacing d, are simply pressed onto the sample for analysis. A current I is injected through the outer points by means of the current source, thus creating a variation in potential. The tension U is measured between the two inner points, which are connected to the voltmeter of the current generator.

In this configuration the conductivity of the sample, expressed in S/cm, is given by the following expression: σ = (K x I) / (U x e) where :

K is a coefficient dependent on the position of the contacts on the sample surface.

When the points are aligned and equidistant, K is equal to: IT/log(2).

I is the value of the injected current, expressed in amperes. U is the measured value of the tension, expressed in volts. e is the thickness of the sample, expressed in cm.

This expression can only be used when the thickness of the material is negligible compared with the distance d that exists between two points (e/d < 0.25). To obtain sufficiently low thicknesses and thus be able to calculate the conductivity of the material, it is recommended to perform the measurement on a non- conductive support (for example a glass slide) coated with the material for analysis obtained by the evaporation of a dilute solution. To improve the homogeneity of the coating for^' analysis, it is also recommended to use the deposition technique known as spin coating.

As indicated above, the polythiophenes used comprise at least one repeat unit of formulae (I) to (III) below:

in which formulae: the radicals Ri to R₄, which are identical or different, are selected from the group comprising hydrogen; a radical -R, -OR, -COOR or -OCOR, where R is a linear or branched or cyclic Cι-C₂o~alkyl radical optionally comprising a heteroatom such as oxygen; a halogen atom; a nitro radical; a cyano radical; an alkylcyano radical; and a solubilizing group, it being understood that at least one radical Ri to R₄ is a solubilizing group; and

Z is -CH=CH- or -C≡C- . Preferably, if the radicals Rx and R₃ of the repeat unit of formula (I) are identical, the radicals R₂ and R₄ are different, and vice-versa. The solubilizing groups are preferably selected from the group comprising:

•a carboxyl radical (-COOH) or a carboxylate radical (-COO^~M⁺, where M is an alkali metal such as sodium or potassium, an alkaline earth metal, or an organic amine such as a primary, secondary or tertiary amine, an alkanolamine or an amino acid) ;

•a sulphonic acid radical (-SO₃H) or a sulphonate radical (-S0₃ ^~M⁺, M being as defined above) ;

•a primary, secondary or tertiary amine radical and more particularly a radical of the type -NH₂, -NHRa or

-N(Ra)₂, where Ra, which are identical or different, are a linear or branched or cyclic Cι~ to C₂n-alkyl radical optionally comprising a heteroatom such as oxygen, and their salts with mineral or organic acids, for example NH₃ ⁺ X^", RNH₂ ⁺ X^" or (R)₂NH⁺ X^" respectively, where X is a halogen atom, preferably chlorine, or an ion derived from a carboxylic acid, such as acetate or lactate

(initially CH₃COO^", but according to the list below it is also necessary to include lactate) ; *a quaternary ammonium radical, for example -

N(Rb)₃ ⁺ Y^", where Y = Br, Cl, alkyl (C1-C4) -0S0₃ or tosylate, and Rb, which are identical or different, are linear or branched Cι-C₂o-alkyls optionally comprising a heteroatom such as oxygen, or two of them form a heterocycle with the nitrogen;

•a hydroxyl radical; and

• a poly (C₂-C₃-alkylene oxide) radical.

As indicated above, the carboxylic or sulphonic acid groups may or may not be neutralized, especially with a base such as sodium hydroxide, 2-amino-2- methylpropanol, triethylamine or tributylamine .

Furthermore, the amine radicals may or may not be neutralized with a mineral acid such as hydrochloric acid, or with an organic acid such as acetic or lactic acid, for example.

Moreover, it should be pointed out that said solubilizing radicals can be joined to the ring via a spacer group such as a radical -R"-, -OR"-, -OCOR"- or -COOR"-, where R" is a linear or branched or cyclic Ci- C₂o-alkyl radical optionally comprising one or more heteroatoms such as oxygen, for example.

Preferably, the radicals Ri to R₄, which are identical or different, are selected from hydrogen and R, -OR, -OCOR or -COOR, where R is a linear or branched Cι-Cι₂-alkyl radical, more particularly Cι-C₆-alkyl radicals, more specifically C₆ ;C₈ ; Cι₂ radicals, and from the following neutralized or non-neutralized solubilizing groups: -COOH, -COO^"M⁺, -CH₂COOH, -CH₂-COO^"

M⁺, -(CH₂)₂COOH, , -(CH₂)2COO^"M⁺, -(CH₂)₃COOH, -(CH₂)₃COO^"

M⁺, -CH₂OH, -(CH₂)₆OH, - (CH₂) S0₃H, - (CH₂) -S0₃ ^~M⁺,

(CH₂)₂S0₃H, -(CH₂)₂-S0₃-M⁺, -(CH₂)₃S0₃H, -(CH₂)₃-S0₃ ^~

M⁺,-0(CH₂)₃S0₃H, -0(CH₂)₃-S0₃ ^"M⁺, -0 (CH₂) ₃N (CH₂CH₃) z , [ (CH₂)₂0]_xCH₂CH₂0H and - [ (CH₂) ₂0] _xCH₂CH₂OCH₃, where x is a mean number between 0 and 200.

Also, the conductive polythiophene can comprise at least one repeat unit of formulae (I) to (III) , indicated above, in which the radicals Ri to R₄, which are identical or different, are selected from the group comprising hydrogen, a radical -R, -OR, -COOR or -OCOR, where R is such as defined above, and more preferably is a linear or branched Cι-C₂n-alkyl radical, a halogen atom, a nitro radical, a cyano radical and an alkylcyano radical.

In one preferred embodiment of the invention, the conductive polymer used contains at least one repeat unit of formulae I.

In the case of this embodiment, are preferred polymers comprising only units of formula (I) in which the radicals different from the solubilizing radicals are hydrogen atoms. In the case of this embodiment, polymers comprising only units of formula (I) in which the radicals different from the solubilizing radicals are hydrogen atoms are such that the solubilizing radical (s) of at least one repeat unit are joined to the ring via a spacer.

According to this embodiment, the polymer comprises at least one unit of formulae (I) to (III) with at least one solubilizing group, and at least one unit of formulae (I) to (III) without solubilizing groups.

In another preferred embodiment of the invention, the conductive polymer used contains at least one repeat unit of formulae I with at least one solubilizing group, and at least one unit of formulae

(I) without solubilizing groups.

Furthermore, the total mean number of repeat units in the conductive polythiophene is generally between 5 and 500, more particularly between 5 and 450 and preferably between 8 and 400.

Thus the polymers advantageously have weight- average molecular weights of between 200 and 500,000 g/mol, more particularly of between 200 and 200,000 g/mol and preferably of between 200 and 100,000 g/mol. The molecular weight can be determined usually by using gel permeation chromatography or light scattering.

In one particular embodiment of the invention, the conductive polymer used contains at least one repeat unit in which at least one of the radicals is a solubilizing group so that the resulting polymer is soluble or dispersible in the medium of the composition, in terms of the invention. In another preferred embodiment of the invention, the conductive polymer used contains at least one solubilizing group per repeat unit, so that the resulting polymer is soluble or dispersible in the medium of the composition, in terms of the invention. The conductive polythiophenes present in the composition according to the invention are especially in the book entitled "Handbook of organic conductive molecules and polymers" - Wiley 1997 - New York, vol. 1, 2, 3; in the review Can. J. Chem. vol. 64, 1986; in the article by the authors RASMUSSEN S.C., PICKENS J.C. and HUTCHISON J.E. entitled "A new, general approach to tuning the properties of functionalized polythiophenes: The oxidative polymerization of monosubstituted bithiophenes", taken from the review Chem. Mater. 1998, vol. 10, no. 7, pages 1990-1999; and in the article by the same authors entitled "Highly conjugated, water- soluble polymers via direct oxidative polymerization of monosubstituted bithiophenes", taken from the review Macromolecules 1998, 31, pages 933-936.

Thus the polymerization can be carried out by chemical or electrochemical oxidation of the corresponding thiophene monomer or by polycondensation. By way of illustration, the polythiophenes of formulae (I) and (II) can be obtained by oxidative polymerization (for example with an FeCl₃ catalyst) ; by the polycondensation of dihalogenated thiophene catalysed by nickel or palladium complexes (e.g. NiCl₂ (dppe) ₂) ; by a Suzuki coupling (coupling between a halogen group, for example bromine, and a boronic acid catalysed by a palladium complex and a base to give a coupling of the type AA-BB (reaction of monomers of the type A-X-A with B-X'-B) or of the type A-B (reaction of several monomers of the type A-X-B) ) ; by a Stille coupling (formation of a carbon-carbon bond in the presence of a Pd-based catalyst; of the type AA-BB or A-B) ; by a Reike polymerization (organozinc in the presence of a nickel complex) ; by a polymerization of the McCulloch type; etc.

The vinylene polythiophenes of formula (III) in which Z is -CH=CH- can be obtained especially by a Gilch polymerization of 2, 5-bis (bromoalkylene) thiophene in the presence of a strong base (potassium tert- butylate) ; by polymerization by the Wessling method via the use of a precursor based on sulphonium salts, and pyrolysis; or by a Wittig or Wittig-Horner reaction.

The ethynylene polythiophenes of formula (III) in which Z is -C=C- can be obtained by a Heck-Sonogashira coupling (of the type AA-BB or A-B; formation of a carbon-carbon bond between a terminal acetylenic (or true acetylenic) group and a bromo or iodo group catalysed by a palladium/copper complex (PdCl₂ (PPh₃) ₃, Cul or Cu(Oac)₂), in the presence of a base such as triethylamine, diisopropylamine, piperidine, etc.); or by the metathesis of alkynes in the presence of a molybdenum complex (Mo(CO)g).

In general, the functionalization of the polythiophenes, or in other words the introduction of the solubilizing or non-solubilizing group (s), is performed on the monomer before it is polymerized.

In some cases the solubilizing group is obtained as a result of treating the polymer. This is the case in particular of the carboxylic acid group, which can be obtained by hydrolysis of the corresponding ester.

Preferably, the solubilizing groups are selected from carboxylic acid groups; sulphonic acid groups; tertiary amine radicals; quaternary ammonium groups such as -NRb₃ ⁺ Y^", where Y = Br, Cl, alkyl (Cι-C₄) -OS0₃ or tosylate, Rb, which are identical or different, are a linear or branched Cι-C₂₀-alkyl radical optionally joined to the ring by a spacer, preferably a Cι-C₂o- alkyl radical; and their salts. The carboxylic or sulphonic acid groups may or may not be neutralized.

Preferably, the conductive polythiophene has formula (II) in which Ri or R₂ is a group -COOH; CH₂COOH; -(CH₂)₂COOH ;-(CH₂)₃COOH the carboxylic group being neutralized or not , the other being a hydrogen atom.

This polymer is soluble in the medium of the composition. More particularly, this polymer is preferably soluble in water. The conductive polymers are generally present in the composition in proportions of at least 0.001% by weight, more particularly of at least 0.1% by weight, preferably of at least 0.1% by weight and particularly preferably of at least 0.5% by weight, based on the total weight of the composition. Furthermore, the content of conductive polymer is advantageously at most 50% by weight, more particularly at most 30% by weight and preferably at most 10% by weight, based on the total weight of the composition.

In one particularly advantageous embodiment of the invention, the content of conductive polymer is between

0.1 and 50% by weight, more particularly between 0.1 and 30% by weight and preferably between 0.5 and 10% by weight, based on the total weight of the composition.

Medium

The cosmetically acceptable medium of the cosmetic composition is preferably an aqueous medium consisting of water and can advantageously comprise one or more organic solvents that are acceptable from the cosmetic point of view, including, more particularly, alcohols such as ethyl alcohol, isopropyl alcohol, benzyl alcohol and phenylethyl alcohol, glycols or glycol ethers, for example ethylene glycol monomethyl, monoethyl and monobutyl ethers, propylene glycol or its ethers, for example propylene glycol monomethyl ether, butylene glycol, dipropylene glycol, and diethylene glycol alkyl ethers, for example diethylene glycol monoethyl ether or monobutyl ether, or polyols such as glycerol. Other solvents which can be used are polyethylene glycols, polypropylene glycol and mixtures of all these compounds .

The solvent (s) can be present in concentrations of between 0.5 and 20% and preferably of between 2 and 10% by weight, based on the total weight of the composition. Additives

The cosmetic composition can also comprise an effective amount of other agents already known in the prior art for the treatment of human keratin fibres. Examples which may be mentioned are thickeners, antioxidants, perfumes, dispersants, conditioners, including especially cationic or amphoteric polymers, opacifiers, sequestering agents such as EDTA and etidronic acid, UV filters, waxes, volatile or nonvolatile cyclic, linear or branched silicones which may or may not be organomodified (especially with amine groups) , preservatives, ceramides, pseudoceramides, vegetable, mineral or synthetic oils, vitamins or provitamins such as panthenol, and non-ionic, anionic, amphoteric or cationic associative polymers. Surfactants Preferably, the cosmetic composition according to the invention comprises one or more surfactants which can arbitrarily be selected, individually or in mixtures, from anionic, amphoteric, non-ionic, zwitterionic and cationic surfactants.

The following surfactants are particularly suitable for carrying out the present invention: (i) Anionic surfactant (s) :

Examples which may be mentioned in particular (without implying a limitation) of anionic surfactants that can be used, individually or in mixtures, within the framework of the present invention are salts

(particularly alkali metal and especially sodium salts, ammonium salts, amine salts, a ino alcohol salts or magnesium salts) of the following compounds: alkylsulphates, alkyl-ether-sulphates, alkylamido- ether-sulphates, alkylaryl-polyether-sulphates and monoglyceridesulphates ; alkylsulphonates , alkylphosphates, alkylamidesulphonates, alkylarylsulphonates, α-olefinsulphonates and paraffinsulphonates; alkyl (C₆-C₂₄) sulphosuccinates, alkyl (C₆-C24) -ether-sulphosuccinates and alkyl (C₆-C₂₄) - amidesulphosuccinates; alkyl '(C₆-C₂₄) sulphoacetates; acyl (C₆-C₂₄) sarcosinates and acyl (C₆-C₂₄) glutamates . It is also possible to use alkyl (C₆-C₂₄) polyglycoside carboxylic acid esters such as alkylglucoside citrates, alkylpolyglycoside tartrates and alkylpolyglycoside sulphosuccinates; alkylsulphosuccinamates; acylisethionates and N-acyltaurates, the alkyl or acyl radical of all these various compounds preferably containing from 12 to 20 carbon atoms and the aryl radical preferably being a phenyl or benzyl group. Among the other anionic surfactants which can be used, there may be mentioned fatty acid salts such as the salts of oleic acid, ricinoleic acid, palmitic acid, stearic acid and the acids of copra oil or hydrogenated copra oil; and acyllactylates, in which the acyl radical contains 8 to 20 carbon atoms. It is also possible to use alkyl-D-galactosideuronic acids and their salts, polyalkoxylated alkyl (C₆-C₂₄) -ether- carboxylic acids, polyalkoxylated alkyl (C₆-C₂₄) aryl- ether-carboxylic acids, polyalkoxylated alkyl (C₆-C₂₄) - amido-ether-carboxylic acids and their salts, particularly those containing from 2 to 50 alkylene oxide groups, especially ethylene oxide groups, and mixtures thereof.

(ii) Non-ionic surfactant (s) :

Likewise, non-ionic surfactants are compounds well known per se (cf. especially "Handbook of Surfactants" by M.R. PORTER, published by Blackie & Son (Glasgow and London) , 1991, pp 116-178) and their nature is not critical within the framework of the present invention. Thus they can be selected especially (without implying a limitation) from polyethoxylated and polypropoxylated alcohols, alpha-diols and alkylphenols having a fatty chain containing e.g. 8 to 18 carbon atoms, it being possible for the number of ethylene oxide or propylene oxide groups to range from 2 to 50 in particular. The following may also be mentioned: ethylene oxide/ propylene oxide copolymers; condensation products of ethylene and propylene oxides with fatty alcohols; polyethoxylated fatty amides preferably containing from 2 to 30 mol of ethylene oxide; polyglycerolated fatty amides containing an average of 1 to 5 and particularly 1.5 to 4 glycerol groups; polyethoxylated fatty amines preferably containing 2 to 30 mol of ethylene oxide; ethoxylated sorbitan fatty acid esters containing from 2 to 30 mol of ethylene oxide; sucrose fatty acid esters; polyethylene glycol fatty acid esters; alkylpolyglycosides; N-alkylglucamine derivatives; and amine oxides such as alkyl (C₁₀-C₁₄) amine oxides or N- acylaminopropylmorpholine oxides .

(iii) Amphoteric or zwitterionic surfactant (s) :

Amphoteric or zwitterionic surfactants, whose nature is not critical within the framework of the present invention, can be especially (without implying a limitation) aliphatic secondary or tertiary amine derivatives in which the aliphatic radical is a linear or branched chain containing 8 to 18 carbon atoms and at least one water-solubilizing anionic group (for example carboxylate, sulphonate, sulphate, phosphate or phosphonate) ; alkyl (C₈-C₂o) betaines, sulphobetaines, alkyl (C₈-C₂o) amidoalkyl (Cι-C₆) betaines or alkyl (C₈-C₂o) ~ amidoalkyl (Ci-Cβ) sulphobetaines may also be mentioned. Among the amine derivatives, there may be mentioned the products sold under the name MIRANOL, such as those described in patents US-2 528 378 and US-2 781 354 and classified in the CTFA dictionary, 3rd edition, 1982, under the names Amphocarboxyglycinates and Amphocarboxypropionates, which have the following respective structures:

R₂-CONHCH₂CH₂-N(R₃) (R₄) (CH₂COO^~) in which: R₂ is the alkyl radical of an acid R₂-COOH present in hydrolysed copra oil, or a heptyl, nonyl or undecyl radical, R₃ is a beta-hydroxyethyl group and R₄ is a carboxymethyl group; and

R₂'-CONHCH₂CH₂-N(B) (C) in which: B is -CH₂CH₂OX', C is -(CH₂)_ZY', where z = 1 or 2, X' is the group -CH₂CH₂-COOH or a hydrogen atom, Y' is -COOH or the radical -CH₂-CHOH-S0₃H, and R₂' is the alkyl radical of an acid R₉-COOH present in copra oil or hydrolysed linseed oil, an alkyl radical, especially a Cη- , C₉-, Cii- or Ci₃-alkyl radical, a Cι₇-alkyl radical or its iso form, or an unsaturated Cχ radical.

These compounds are classified in the CTFA dictionary, 5th edition, 1993, under the names Disodium Coco-ampho-diacetate, Disodium Lauro-ampho-diacetate, Disodium Capryl-ampho-diacetate, Disodium Caprylo- ampho-diacetate, Disodium Coco-ampho-dipropionate, Disodium Lauro-ampho-dipropionate, Disodium Capryl- ampho-dipropionate, Disodium Caprylo-ampho- dipropionate, Lauro-ampho-dipropionic acid and Coco- ampho-dipropionic acid.

The cocoamphodiacetate marketed under the trade name Miranol" C2M concentre by Rhodia Chimie may be mentioned as an example. (iv) Cationic surfactants:

The following cationic surfactants may be mentioned in particular (without implying a limitation) : salts of optionally polyalkoxylated primary, secondary or tertiary fatty amines; quaternary ammonium salts such as tetraalkylammonium, alkylamidoalkyltrialkylammonium, trialkylbenzylammonium, trialkylhydroxyalkylammonium or alkylpyridinium chlorides or bromides; imidazoline derivatives; or amine oxides of cationic character.

The amounts of surfactants present in the composition according to the invention can vary from 0.01 to 40% and preferably from 0.5 to 30% of the total weight of the composition.

Of course, those skilled in the art will take care to choose the abovementioned possible complementary compound (s) in such a way that the advantageous properties intrinsically attached to the dyeing composition according to the invention are unaffected or substantially unaffected by the addition (s) envisaged. The composition which has now been described is applied to the keratin material and in particular to dry or wet keratin fibres. The medium of the composition is then evaporated off or allowed to evaporate at between 20 and 120°C, preferably at between 20 and 80°C, until the fibres are dry.

Likewise, it can also be envisaged to apply the composition to dry or wet fibres and then rinse said fibres and dry them at between 20 and 120°C.

A concrete Example is indicated below in order to illustrate the invention without thereby implying a limitation. EXAMPLE Synthesis of poly (thiophen-3-acetic acid)

Procedure Preparation of the polymer poly (ethyl thiophen-3- acetate)

25 ml of dry chloroform are introduced into a Schlenk tube under argon and degassed, and the following reagents are then introduced: 2.5 g of ethyl thiophen-3-acetate (14.7 mmol)

and 1 g of FeCl₃ (6.15 mmol) .

The mixture is stirred for 24 hours under argon at 50°C.

The polymer poly (ethyl thiophen-3-acetate) is then precipitated in heptane.

The polymer is then dissolved in tetrahydrofuran.

Characterization by infrared: C=0 band: 1719 cm^"1; CH₂, CH₃ bands: 2979 cm^-1, 2934 cm^"1; and disappearance of he CH band at 3102 cm^"1 present in the monomer. Hydrolysis of the polymer: poly (ethyl thiophen-3- acetate) to form poly (thiophen-3-acetic acid).

The polymer obtained above is then hydrolysed with an excess of 50 ml of an aqueous sodium hydroxide solution (2 N) for 48 hours at 70°C, this being followed by acidification with concentrated HC1 to precipitate the product, i.e. poly (thiophen-3-acetic acid).

The polymer is then filtered off and washed several times with distilled water to remove the traces of catalyst.

Infrared characterization of the polymer:

C=0 band: 1740 cm^-1; COO: 1580 cm^"1; OH (broad band at 3000-3500 cm^"1) .

Neutralization of the polymer poly (thiophen-3- acetic acid) :

The polymer poly (thiophen-3-acetic acid) (2 g) is dissolved in tetrahydrofuran (30 g) and neutralized at a rate of 1 mol of sodium hydroxide per mol of carboxylic acid. Water (30 g) is then added. The tetrahydrofuran is evaporated off.

This gives a 6% aqueous solution of poly (thiophen- 3-acetic acid) in the form of a sodium salt.

Formulation comprising the polymer obtained: Composition:

Polymer described above 4%

Aminomethylpropanol qs pH 7

Synthalen K 1%

Ethanol 10% Water qsp 100 g

Composition 1 of ^' conductive polymer obtained according to the above Example (0.1 g per g of hair) was applied to locks of natural chestnut hair at room temperature (20°C) . The locks were then dried. The locks have a very shiny appearance with golden highlights visible especially when the locks are observed at a glancing angle.

The hair has the advantage of not being perceived as having a greasy feel, and the optical properties ^described above persist over time (unchanged after 12 hours) .

Claims

1. Use, as an agent for imparting an optical effect to human keratin materials and more particularly to human keratin fibres, of a composition which comprises, in a cosmetically acceptable medium, at least one conductive polythiophene that is present in a soluble or dispersible form in said medium and comprises at least one repeat unit of formulae (I) to (III) below:

in which formulae: the radicals Ri to R₄, which are identical or different, are selected from the group comprising hydrogen; a radical -R, -OR, -COOR or -OCOR, where R is a linear, branched or cyclic Cι-C₂o^_alkyl radical optionally comprising a heteroatom such as oxygen; a halogen atom; a nitro radical; a cyano radical; an alkylcyano radical; and a solubilizing group, it being understood that at least one radical among Rx to R₄ is a solubilizing group; and

Z is -CH=CH- or -C≡C-. 2. Use, as an agent for colouring human keratin materials and more particularly human keratin fibres, of a composition which comprises, in a cosmetically acceptable medium, at least one conductive polythiophene that absorbs light in the visible spectrum, is present in a soluble or dispersible form in said medium and comprises at least one repeat unit of formulae (I) to (III) below:

in which formulae: the radicals Ri to R₄, which are identical or different, are selected from the group comprising hydrogen; a radical -R, -OR, -COOR or -OCOR, where R is a linear, branched or cyclic Cι-C₂o-alkyl radical optionally comprising a heteroatom such as oxygen; a halogen atom; a nitro radical; a cyano radical; an alkylcyano radical; and a solubilizing group, it being understood that at least one radical among Ri to R is a solubilizing group; and

Z is -CH=CH- or -C≡C- . 3. Use according to anyone of the preceding claims, characterized in that the radicals Ri to R₄, which are identical or different, are selected from the group comprising hydrogen; a radical -R, -OR, -COOR or -OCOR, where R is a linear or branched Cι-C₂₀-alkyl radical; a halogen atom; a nitro radical; a cyano radical; an alkylcyano radical; and a solubilizing group, it being understood that at least one radical among Ri to R₄ is a solubilizing group. . Use according to anyone of the preceding Claims, characterized in that the solubilizing groups are selected from the group comprising:

• a carboxyl radical or a carboxylate radical;

• a sulphonic radical or a sulphonate radical;

• a primary, secondary or tertiary amine radical;

• a quaternary ammonium radical; • a hydroxyl radical; and

• a poly (C₂-C₃-alkylene oxide) radical, it being understood that said solubilizing radicals may or may not be joined to the ring via a spacer group. 5. Use according to anyone of the preceding Claims, characterized in that the solubilizing groups are selected from the group comprising:

• a carboxyl radical (-COOH) or a carboxylate radical (-COO^~M⁺, where M is an alkali metal, an alkaline earth metal, an organic amine, an alkanolamine or an amino acid) ;

• a sulphonic radical (-S0₃H) or a sulphonate radical (-S0₃ ^~M⁺, M being as defined above) ;

• a primary, secondary or tertiary amine radical; • a quaternary ammonium radical such as -NRb₃ ⁺ Y^", where Y = Br, Cl, alkyl (Cι-C₄) -OS0₃ or tosylate, and Rb, which are identical or different, are a linear or branched Cι-C₂o^_alkyl radical optionally comprising a heteroatom, or two of them form a heterocycle with the nitrogen;

• a hydroxyl radical; and

• a poly (C₂-C₃-alkylene oxide) radical, it being understood that said solubilizing radicals may or may not be joined to the ring via a spacer group. β. Use according to anyone of Claims 4 or 5, characterized in that the spacer group, which is identical or different, is a radical -R"-, -OR"-, OCOR"- or -COOR"-, where R" is a linear or branched Ci- C₂₀-alkyl radical optionally comprising a heteroatom.

7. Use according to anyone of the preceding claims, characterized in that the radicals Ri to R₄, which are identical or different, are selected from hydrogen and R, -OR, -OCOR or -COOR, where R is a linear or branched Cι-Cι₂-alkyl radical, and from the following neutralized or non-neutralized solubilizing groups: -COOH, -COO^~M⁺, -CH₂COOH, -CH₂-COO^"M⁺,

(CH₂)₂COOH, -(CH₂)₂COO^"M⁺, -(CH₂)₃COOH, - (CH₂) ₃COO^"M⁺, - CH₂OH, -(CH₂)₆OH, -(CH₂)S0₃H, - (CH₂) -S0₃ ^"M⁺, -(CH₂)₂S0₃H, -(CH₂)₂-S0₃ ^"M⁺, -(CH₂)₃S0₃H, - (CH₂) ₃-S0₃ ^"M⁺, -0 (CH₂) ₃SO₃H, - 0(CH₂)₃-S0₃ ^"M⁺, -0(CH₂)3N(CH₂CH3)2, - [ (CH₂) ₂0] _xCH₂CH₂OH and - [ (CH₂) ₂0]_xCH₂CH₂OCH₃, where x is a mean number between 0 and 200.

8. Use according to anyone of the preceding claims, characterized in that the conductive polythiophene comprises at least one repeat unit of formulae (I) to (III) below:

in which formulae: the radicals Ri to R₄, which are identical or different, are selected from the group comprising hydrogen; a radical -R, -OR, -COOR or -OCOR, where R is as previously defined and more preferably is a linear or branched Cι-C₂o-alkyl radical; a halogen atom; a nitro radical; a cyano radical and an alkylcyano radical; and Z is -CH=CH- or -C≡C-.

9. Use according to anyone of Claims 1 to 8, characterized in that the polythiophene contains at least one solubilizing group per repeat unit.

10. Use according to anyone of the preceding claim, characterized in that the polythiophene comprises repeat units of formula (II) in which Ri or R₂ is a group -CH₂COOH or -CH₂COO^"M⁺, the other being a hydrogen atom.

11. Use according to any one of the preceding claims, characterized in that the polythiophene (s) are present in proportions of at least 0.001% by weight, more particularly of at least 0.1% by weight, preferably of at least 0.1% by weight and particularly preferably of at least 0.5% by weight, based on the total weight of the composition.

12. Use according to any one of the preceding claims, characterized in that the polythiophene (s) are present in proportions of at most 50% by weight, more particularly of at most 30% by weight and preferably of at most 10% by weight, based on the total weight of the composition.

13. Use according to any one of the preceding claims, characterized in that the cosmetically acceptable medium is selected from the group comprising water and a water/solvent mixture.

14. Use according to Claim 11, characterized in that the solvent (s) are selected from alcohols, glycols, glycol ethers, polyols, polyethylene glycols, polypropylene glycol and mixtures thereof. 15. Use according to any one of the preceding claims, characterized in that it also comprises at least one non-ionic, anionic, cationic, amphoteric or zwitterionic surfactant. 004/066

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16. Use according to one of the preceding claims, characterized in that the composition is applied to dry or wet fibres and the medium is then evaporated off or allowed to evaporate at between 20 and 50°C until the fibres are dry.

17. Dyeing composition for human keratin fibres and more particularly hair, characterized in that it comprises, in a cosmetically acceptable medium, an effective amount of at least one conductive polythiophene that absorbs light in the visible spectrum, is present in a soluble or dispersible form in said medium and comprises at least one repeat unit of formulae (I) to (III) below:

in which formulae: the radicals Ri to R₄, which are identical or different, are selected from the group comprising hydrogen; a radical -R, -OR, -COOR or -OCOR, where R is a linear, branched or cyclic Cι-C₂o-alkyl radical, optionally comprising a heteroatom such as oxygen; a halogen atom; a nitro radical; a cyano radical; an alkylcyano radical; and a solubilizing group, it being understood that at least one radical Ri to R₄ is a solubilizing group; and

Z is -CH=CH- or -C≡C- .

18. Composition according to the preceding claim, characterized in that the radicals R_x to R₄, which are identical or different, are selected from the group comprising hydrogen; a radical -R, -OR, -COOR or -OCOR, where R is a linear or branched Cι-C₂_^_alkyl radical; a halogen atom; a nitro radical; a cyano radical; an alkylcyano radical; and a solubilizing group, it being understood that at least one radical among Ri to R₄ is a solubilizing group. 19. Composition according to anyone of claims 17 or 18, characterized in that the solubilizing groups are selected from the group comprising:

• a carboxyl radical or a carboxylate radical;

• a sulphonic radical or a sulphonate radical; • a primary, secondary or tertiary amine radical;

• a quaternary ammonium radical;

• a hydroxyl radical; and

• a poly (C₂-C₃-alkylene oxide) radical, it being understood that said solubilizing radicals may or may not be joined to the ring via a spacer group.

20. Composition according to the anyone of claims

17 to 19, characterized in that the solubilizing groups are selected from the group comprising: • a carboxyl radical (-CO0H) or a carboxylate radical (-COO^~M⁺, where M is an alkali metal, an alkaline earth metal, an organic amine, an alkanolamine or an airtino acid) ;

• a sulphonic radical (-SO₃H) or a sulphonate radical (-S0₃ ^"M⁺, M being as defined above) ;

• a primary, secondary or tertiary amine radical;

• a quaternary ammonium radical such as -NRb₃ ⁺ Y^", where Y = Br, Cl, alkyl (C₁-C₄) -0S0₃ or tosylate, and Rb, which are identical or different, are a linear or branched Cι-C₂o^_alkyl radical optionally comprising a heteroatom, or two of them form a heterocycle with the nitrogen;

• a hydroxyl radical; and

• a poly (C₂-C₃-alkylene oxide) radical, it being understood that said solubilizing radicals may or may not be joined to the ring via a spacer group

21. Composition according to anyone of Claims 17 or 20, characterized in that the radicals Ri to R₄, which are identical or different, are selected from hydrogen and R, -OR, -OCOR or -COOR, where R is a linear or branched Cι-Cι₂-alkyl radical, and from the following neutralized or non-neutralized solubilizing groups: -COOH, -COO^~M⁺, -CH₂COOH, -CH₂-COO^"M⁺, -(CH₂)₂COOH,

-(CH₂)₂COO^"M⁺, -(CH₂)₃COOH, - (CH₂) ₃COO^"M⁺, -CH₂0H,

(CH₂)₆OH, -(CH₂)S0₃H, -(CH₂)-S0₃ ^"M⁺, (CH₂)₂S0₃H,

-(CH₂)₂-S0₃ ^"M⁺, -(CH₂)₃S0₃H, - (CH₂) ₃-S0₃ ^"M⁺, -0 (CH₂) ₃SO₃H, -

0(CH₂)₃-S0₃ ^"M⁺, -0(CH₂)₃N(CH₂CH₃)₂, - [ (CH₂) ₂0] _xCH₂CH₂OH and - [ (CH₂) ₂0]_xCH₂CH₂OCH₃, , where x is a mean number between 0 and 200.

22. Composition according to anyone of Claims 17 to 21, characterized in that the conductive polythiophene comprises at least one repeat unit of formulae (I) to (III) below:

in which formulae: the radicals Ri to R₄, which are identical or different, are selected from the group comprising hydrogen; a radical -R, -OR, -COOR or -OCOR, where R is as previously defined and more particularly is a linear or branched Cι-C₂₀-alkyl radical; a halogen atom; a nitro radical; a cyano radical and an alkylcyano radical; and Z is -CH=CH- or -CeC-.

23. Composition according to anyone of Claims 17 to 21, characterized in that the polythiophene contains at least one solubilizing group per repeat unit.

24. Composition according to the preceding claim, characterized in that the polythiophene comprises repeat units of formula (II) in which Ri or R₂ is a group -CH₂COOH or -CH₂COO^"M⁺, the other being a hydrogen atom.

25. Composition according to one of Claims 17 to 24, characterized in that the polythiophene content is at least 0.001% by weight, more particularly at least 0.1% by weight, preferably at least 0.1% by weight and particularly preferably at least 0.5% by weight, based on the total weight of the composition. 26. Composition according to one of Claims 17 to 25, characterized in that the polythiophene content is at most 50% by weight, more particularly at most 30% by weight and preferably at most 10% by weight, based on the total weight of the composition.