WO2015086675A1

WO2015086675A1 - Process for dyeing keratin fibres using coloured oligomers and/or polymers derived from self-oxidizing compounds, composition and colouring agent for the same

Info

Publication number: WO2015086675A1
Application number: PCT/EP2014/077220
Authority: WO
Inventors: Stéphane SABELLE
Original assignee: L'oreal
Priority date: 2013-12-13
Filing date: 2014-12-10
Publication date: 2015-06-18
Also published as: FR3014686B1; FR3014686A1

Abstract

The invention relates to a) a process for dyeing keratin materials using a colouring agent chosen from coloured oligomers and polymers obtained from the polycondensation of i) self-oxidizing compounds in the presence of ii) one or more ingredients chosen from radical initiators and/or chemical oxidizing agents, b) a composition comprising one or more coloured oligomers and/or one or more coloured polymers as defined previously and c) a coloured oligomeric or polymeric colouring agent obtained by reaction between i) and ii) as defined previously, and to the use of the coloured oligomer(s) or polymer(s) for dyeing keratin materials. The dyeing process and the composition according to the invention especially afford a long-lasting colouring on keratin fibres, which is strong, chromatic and/or homogeneous.

Description

PROCESS FOR DYEING KERATIN FIBRES USING COLOURED OLIGOMERS AND/OR POLYMERS DERIVED FROM SELF-OXIDIZING COMPOUNDS, COMPOSITION AND

COLOURING AGENT FOR THE SAME The invention relates to a) a process for dyeing keratin materials using a colouring agent chosen from coloured oligomers and polymers obtained from the polycondensation of i) self-oxidizing compounds in the presence of ii) one or more ingredients chosen from radical initiators and/or chemical oxidizing agents other than hydrogen peroxide, b) a composition comprising one or more coloured oligomers and/or one or more coloured polymers as defined previously and c) a coloured oligomeric or polymeric colouring agent obtained by reaction between i) and ii) as defined previously, and to the use of the coloured oligomer(s) or polymer(s) for dyeing keratin materials, in particular keratin fibres and preferably human keratin fibres such as the hair, or the skin.

It is known practice to dye keratin fibres by direct dyeing or semi-permanent dyeing. Direct dyeing or semi-permanent dyeing consists in introducing colour via a coloured molecule that becomes adsorbed onto the surface of the hair or that penetrates into the hair. Thus, the process conventionally used in direct dyeing consists in applying to the keratin fibres direct dyes, which are coloured and colouring molecules that have affinity for the fibres, in leaving the fibres in contact with the colouring molecules and in then optionally rinsing the fibres. Generally, this technique leads to chromatic colourings.

Currently, the main direct dyes used in hair dyeing are dyes with low molecular weights. Due to their size, they generally show good affinity for the hair fibre. However, due to their solubility in water and their size, they have low persistences towards shampooing. Furthermore, natural and fundamental colours are generally difficult to achieve.

The synthesis of direct dyes with high molecular weights has also been described (WO 201 1/006946, WO 201 1/1 13676 and WO 201 1/1 13675). A priori, these coloured polymers do not penetrate into the hair fibre. Instead, they have a tendency to be deposited around the keratin fibres, which brings about in particular problems of feel and/or of persistences towards shampooing.

Moreover, certain pigments intended for the skin do not always have satisfactory covering power or their starting material is expensive.

There thus exists a real need to find novel direct dyes that are capable of building up satisfactorily on the hair fibre, of having excellent persistences, in particular towards shampooing, of having a very good feel and of achieving natural and fundamental colours and/or which give keratin fibres a colouring that is sparingly selective (i.e. for which the difference in colouring along the same keratin fibre between its end and its root is low, or homogeneous from one fibre to another). There is also a need to find novel pigments that are easier to access and less expensive and/or that have better covering power.

This (these) aim(s) are achieved with the present invention, a first subject of which is a process for dyeing keratin materials using at least one colouring agent, obtained from the polycondensation of i) self-oxidizing compounds that react together in the presence of one or more ingredients ii) chosen from radical initiators and chemical oxidizing agents other than hydrogen peroxide.

Another subject is a colouring agent obtained from the polycondensation i) of self- oxidizing compounds that react together in the presence ii) of at least one radical initiator and/or of at least one chemical oxidizing agent.

Another subject of the invention is a composition comprising at least one colouring agent as defined previously, preferably not comprising any oxidation base and/or hydrogen peroxide.

Another subject relates to the use of the colouring agent as defined previously for dyeing keratin fibres, especially human keratin fibres such as the hair.

The colourings obtained with the dyeing process, with the composition or using the colouring agent(s) of the invention, are aesthetic, vivid, chromatic and/or very persistent with regard to common attacking factors, such as sunlight, perspiration or sebum and towards other hair treatments, such as successive shampooing, while at the same time being friendly to the keratin fibres. The intensity obtained is particularly noteworthy. This is likewise the case for the homogeneity of the colour of the keratin fibres, i.e. of low selectivity from the root to the end.

For the purposes of the present invention, and unless otherwise indicated:

^■ The term "colouring agent" means an oligomer and/or polymer resulting from a linear or non-linear covalent assemblage, with a number of greater than or equal to 2 repeating units or monomer units, derived from the polycondensation of self- oxidizing compounds solely with each other, i.e. the oligomer and/or polymer chain does not comprise any monomer units derived from an oxidation base, for example; the said colouring agent has a high molecular mass, in particular of greater than or equal to 230 g/mol, preferably of greater than 300 g/mol;

^■ The term "oligomer" means a compound comprising from 2 to 4 monomer units derived from the polycondensation of self-oxidizing compounds solely with each other, i.e. the oligomer chain being free of monomer units derived from an oxidation base;

^■ The term "polymer" means a compound comprising at least 5 monomer units and preferably between 5 and 100 monomer units derived from the polycondensation of self-oxidizing compounds solely with each other, i.e. the polymer chain being free of monomer units derived from an oxidation base;

^■ the "ary or "heteroaryi' radicals or the aryl or heteroaryl part of a radical can be substituted with at least one substituent borne by a carbon atom chosen from:

a Ci-C₈ alkyl radical optionally substituted with one or more radicals chosen from the following radicals: hydroxyl, CrC₄ alkoxy, C₂-C₄ (poly)hydroxyalkoxy, acylamino or amino substituted with two identical or different C1-C4 alkyl radicals which optionally bear at least one hydroxyl group or it being possible for the two radicals to form, with the nitrogen atom to which they are attached, a saturated or unsaturated and optionally substituted 5- to 7-membered and preferably 5- or 6-membered heterocycle optionally comprising another nitrogen or non-nitrogen heteroatom;

a halogen atom;

a hydroxyl group;

a C1-C4 alkoxy radical;

- a C2-C4 (poly)hydroxyalkoxy radical;

an amino radical;

an amino radical substituted with one or two identical or different Ci-C₆ alkyl radicals optionally bearing at least:

i) one hydroxyl group,

ii) one amino group optionally substituted with one or two C1-C3 alkyl radicals which are optionally substituted,

iii) one quaternary ammonium group -N⁺R'R"R"', M^" for which R', R" and R'", which may be identical or different, represent a hydrogen atom or a C1-C4 alkyl group and M^" represents the anionic counterion,

- an acylamino (-NR-C(O)-R') radical in which the R radical is a hydrogen atom or a C1-C4 alkyl radical optionally bearing at least one hydroxyl group and the R' radical is a C1-C4 alkyl radical;

a carbamoyl ((R)₂N-C(0)-) radical in which the R radicals, which may be identical or different, represent a hydrogen atom or a C1-C4 alkyl radical optionally bearing at least one hydroxyl group;

an alkylsulfonylamino (R'-S(0)₂-N(R)-) radical in which the R radical represents a hydrogen atom or a C1-C4 alkyl radical optionally bearing at least one hydroxyl group and the R' radical represents a C1-C4 alkyl radical or a phenyl radical;

- an aminosulfonyl ((R)2N-S(0)₂-) radical in which the R radicals, which may be identical or different, represent a hydrogen atom or a C1-C4 alkyl radical optionally bearing at least one hydroxyl group;

a carboxyl radical in the acid or salified form (preferably in the form salified with an alkali metal or a substituted or unsubstituted ammonium);

- a cyano group;

a nitro or nitroso group;

a polyhaloalkyl group, preferably trifluoromethyl; ^■ the cyclic or heterocyclic part of a non-aromatic radical may be substituted with at least one substituent chosen from the following groups:

hydroxyl;

C1-C4 alkoxy or C₂-C₄ (poly)hydroxyalkoxy;

- C1-C4 alkyl;

alkylcarbonylamino (R-C(O)-NR'-), in which the R' radical is a hydrogen atom or a C1-C4 alkyl radical optionally bearing at least one hydroxyl group and the R radical is a C1-C2 alkyl radical or an amino radical optionally substituted with one or two identical or different C1-C4 alkyl groups themselves optionally bearing at least one hydroxyl group;

alkylcarbonyloxy (R-C(O)-O-), in which the R radical is a C1-C4 alkyl radical or an amino group optionally substituted with one or two identical or different C1-C4 alkyl groups themselves optionally bearing at least one hydroxyl group;

- alkoxycarbonyl or aminocarbonyl (R-G-C(O)-), in which the R radical is a C

C₄ alkoxy radical and G is an oxygen atom or an amino group optionally substituted with a C1-C4 alkyl group itself optionally bearing at least one hydroxyl group;

^■ a cyclic or heterocyclic radical or a non-aromatic part of an aryl or heteroaryl radical may also be substituted with one or more oxo groups;

^■ an "aryP' radical represents a monocyclic or fused or non-fused polycyclic carbon- based group comprising from 6 to 22 carbon atoms, at least one ring of which is aromatic; preferably, the aryl radical is a phenyl, biphenyl, naphthyl, indenyl, anthracenyl or tetrahydronaphthyl and more preferably phenyl;

- a "heteroaryl radical' represents an optionally cationic, 5- to 22-membered, monocyclic or fused or non-fused polycyclic group comprising from 1 to 6 heteroatoms chosen from nitrogen, oxygen, sulfur and selenium atoms (preferably chosen from N, O and S), at least one ring of which is aromatic; preferably, a heteroaryl radical is chosen from acridinyl, benzimidazolyl, benzobistriazolyl, benzopyrazolyl, benzopyridazinyl, benzoquinolyl, benzothiazolyl, benzotriazolyl, benzoxazolyl, pyridinyl, tetrazolyl, dihydrothiazolyl, imidazopyridyl, imidazolyl, indolyl, isoquinolyl, naphthoimidazolyl, naphthoxazolyl, naphthopyrazolyl, oxadiazolyl, oxazolyl, oxazolopyridyl, phenazinyl, phenoxazolyl, pyrazinyl, pyrazolyl, pyrilyl, pyrazoyltriazyl, pyridyl, pyridinoimidazolyl, pyrrolyl, quinolyl, tetrazolyl, thiadiazolyl, thiazolyl, thiazolopyridinyl, thiazoylimidazolyl, thiopyrylyl, triazolyl, xanthyl and its ammonium salt;

^■ a "cationic heteroaryl radical is a heteroaryl group as defined above which comprises an endocyclic or exocyclic quaternized cationic group, o when the cationic charge is endocyclic, it is included in the electron derealization via the mesomeric effect; for example, it is a pyridinium, imidazolium or indolinium roup:

with R and R' being a heteroaryl substituent as defined previously and particularly a (hydroxy)(CrC₈)alkyl group such as methyl;

o when the cationic charge is exocyclic, it concerns, for example, an ammonium or phosphonium R⁺ substituent, such as trimethylammonium, which is outside the heteroar l, such as pyridyl, indolyl, imidazolyl or naphthalimidyl, in question:

with R a heteroaryl substituent as defined previously and R⁺ an ammonium R_aR_bR_cN⁺-, phosphonium R_aR_bR_cP⁺- or ammonium R_aR_bR_cN⁺-(Ci-C₆)alkylamino group with R_a, R_b and R_c, which may be identical or different, representing a hydrogen atom or a (CrC₈)alkyl group such as methyl;

^■ a "heterocyclic radicai' is a 5- to 22-membered monocyclic or fused or non-fused polycyclic radical which can comprise one or two unsaturations but is non-aromatic, comprising from 1 to 6 heteroatoms chosen from nitrogen, oxygen, sulfur and selenium (preferably chosen from N, O and S);

^■ a "heterocycloalkyl radicai' is a heterocyclic radical comprising at least one saturated ring;

^■ an "alkyi radical is a linear or branched Ci-C₂o and preferably Ci-C₈ hydrocarbon radical;

^■ the term "optionally substituted" applied to the alkyi radical implies that the said alkyi radical may be substituted with one or more radicals chosen from the following radicals: i) hydroxyl, ii) Ci-C₆ alkoxy, iii) acylamino, iv) amino optionally substituted with one or two identical or different Ci-C₄ alkyi radicals, the said alkyi radicals possibly forming with the nitrogen atom that bears them a 5- to 7-membered heterocycle optionally comprising another nitrogen or non-nitrogen heteroatom; v) or a quaternary ammonium group -N⁺R'R"R"', M^" for which R', R" and R'", which may be identical or different, represent a hydrogen atom or a C1-C4 alkyl group, or alternatively -N⁺R'R"R"' forms a heteroaryl such as imidazolium optionally substituted with a C1-C4 alkyl group, and M^" represents the anionic counterion;

an "alkoxy radical' is an alkyl-oxy radical for which the alkyl radical is a linear or branched C1-C10 and preferentially Ci-C₈ hydrocarbon-based radical;

an "alkylthio radical is an alkyl-S- radical for which the alkyl radical is a linear or branched C1-C10 and preferentially Ci-C₈ hydrocarbon-based radical;

when the alkoxy or alkylthio group is optionally substituted, this implies that the alkyl group is optionally substituted as defined hereinabove; an "organic or mineral acid salt" more particularly means the salts chosen from a salt derived from i) hydrochloric acid HCI, ii) hydrobromic acid HBr, iii) sulfuric acid H2SO4, iv) alkylsulfonic acids: Alk-S(0)₂OH such as methanesulfonic acid and ethanesulfonic acid; v) arylsulfonic acids: Ar-S(0)₂OH such as benzenesulfonic acid and toluenesulfonic acid; vi) citric acid; vii) succinic acid; viii) tartaric acid; ix) lactic acid; x) alkoxysulfinic acids: Alk-0-S(0)OH such as methoxysulfinic acid and ethoxysulfinic acid; xi) aryloxysulfinic acids such as tolueneoxysulfinic acid and phenoxysulfinic acid; xii) phosphoric acid H₃P0₄; xiii) acetic acid CH₃C(0)OH; xiv) triflic acid CF₃SO₃H; and xv) tetrafluoroboric acid HBF₄;

an "anionic counterion" means an anion or an anionic group derived from an organic or mineral acid salt which counterbalances the cationic charge of the dye; more particularly, the anionic counterion is chosen from: i) halides such as chloride or bromide; ii) nitrates; iii) sulfonates, including Ci-C₆ alkylsulfonates: Alk-S(0)₂0^" such as methanesulfonate or mesylate and ethanesulfonate; iv) arylsulfonates: Ar- S(0)₂0^" such as benzenesulfonate and toluenesulfonate or tosylate; v) citrate; vi) succinate; vii) tartrate; viii) lactate; ix) alkyl sulfates: Alk-0-S(0)0^" such as methyl sulfate and ethyl sulfate; x) aryl sulfates: Ar-0-S(0)0^" such as benzene sulfate and toluene sulfate; xi) alkoxy sulfates: Alk-0-S(0)₂0^" such as methoxy sulfate and ethoxy sulfate; xii) aryloxy sulfates: Ar-0-S(0)₂0^", xiii) phosphates 0=P(OH)₂-0^" _, 0=P(0>OH 0=P(0^")₃, HO-[P(0)(0^")]w-P(0)(0^")₂ with w being an integer; xiv) acetate; xv) triflate; and xvi) borates such as tetrafluoroborate, xvii) disulfate (0=)₂S(0^")₂ or S0₄ ^2" and monosulfate HS0₄ ^";

the anionic counterion, derived from the organic or mineral acid salt, ensures the electrical neutrality of the molecule; thus, it is understood that when the anion comprises several anionic charges, then the same anion may serve for the electrical neutrality of several cationic groups in the same molecule or else may serve for the electrical neutrality of several molecules; for example, a disulfide dye of formula (I) which contains two cationic chromophores may contain either two "singly charged" anionic counterions or a "doubly charged" anionic counterion such as (0=)₂S(0^")₂ or O=P(0^")₂-OH; ^■ moreover, the addition salts that may be used in the context of the invention are especially chosen from addition salts with a cosmetically acceptable base such as alkaline agents as defined below, for instance alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, aqueous ammonia, amines or alkanolamines;

^■ the term "at least one" is equivalent to the term "one or more"; and

^■ the term "inclusively" for a range of concentrations means that the limits of that range are included in the defined range. i) the self-oxidizing compounds

The process for preparing the colouring agent(s) of the invention uses one or more self-oxidizing compounds, which may be identical or different, and are preferably identical.

The term "self-oxidizing compound" means a colourless or weakly coloured compound, known to those skilled in the art, which can become coloured in the presence of atmospheric oxygen (see, for example, Kirk-Othmer's Encyclopedia of Chemical Technology, "Hair Preparation", 4th Ed., Vol. 12, 1994, p. 904; Ullmann's Encyclopedia of Industrial Chemistry, "Hair preparation" 2002 DOI: 10.1002/14356007.a12_571 ).

In general, the intermediates are compounds which comprise at least one (hetero)aryl group substituted with at least two groups that are electron-donating via the mesomeric effect (+M) such as hydroxyl or amino or (di)(alkyl)amino, (CrC₆)alkoxy with the optionally substituted alkyl group(s) borne by N or O. In particular, these compounds often comprise three electron-donating groups. Preferentially, the self-oxidizing compounds are chosen from trihydroxybenzenes, dihydroxyanilines, diaminophenols, triaminobenzenes, dihydroxynaphthalenes, aminonaphthols, diaminonaphthalenes, dihydroxyindoles, diaminoindoles and aminohydroxyindoles.

More preferentially, the self-oxidizing compounds of the invention are of formulae (I) to (III) below:

(I) (ll) (Ml)

and also salts thereof with mineral or organic acids or bases, optical or geometric isomers thereof, tautomers thereof, and/or solvates thereof such as hydrates;

in which formulae (I) to (III):

• represents a single bond or a double bond;

• X represents i) an amino radical, ii) a Ci-C₆ (di)alkylamino radical which may optionally be substituted with one or more hydroxyl, Ci-C₆ alkoxy, amino, Ci-C₆ alkylamino, carboxylic (-C0₂H) or sulfonic (-S0₃H) radicals; iii) a hydroxyl radical; Ri represents a radical covalently bonded to a carbon atom, chosen from:

i) hydroxyl,

ii) thiol -SH,

iii) C₁-C₁₂ (di)(alkyl)amino in which the alkyl group(s) may be optionally substituted with one or more radicals as follows: a) hydroxyl, b) CrC₆ alkoxy, c) amino, d) amide (-CONH₂), e) C C₆ (di)alkylamino, f) carboxylic (-C0₂H), g) sulfonic (-S0₃H), h) piperidine, i) pyridine, j) pyrrolidine, k) morpholine, I) Ci-C₆ N-alkyl piperazino, m) benzene, n) halogen, o) nitrile, p) tetrahydrofuran, q) CrC₆ N-alkylpyrrolidine, r) imidazole, s) Ci-C₆ trialkylammonium, t) CrC₆ N-alkylimidazolium, u) CrC₆ N,N dialkylpiperazinium, v) Ci-C₆ N,N-dialkylpiperazinium, w) CrC₆ N-alkyl-N'- alkylpiperazinium, x) CrC₆ N-alkylpiperidinium, y) CrC₆ N-alkylmorpholinium, z) Ci-C₆ N-alkylpyrrolidinium, aa) CrC₆ N-alkylpyridinium, ab) (di)(Ci- C₆)alkylacetamido, ac) NHS0₂R₂, ad) C C₆ alkylcarbonyl, ae) urea (-NHCONH₂), af) acetamido CH₃CONH-, ag) -aminocarbonyl -CONH₂.

iv) Ci-C₆ alkyl which may be optionally substituted with one or more radicals a) to ag) as defined for iii) above;

v) Ci-C₆ alkyloxy which may be optionally substituted with one or more radicals a) to ag) as defined for iii) above, the alkyl chain of the alkoxy possibly being interrupted with one or more oxygen atoms;

vi) Ci-C₆ alkylthio which may be optionally substituted with one or more radicals a) to ag) as defined for iii) above;

vii) halogen

viii) -NHPh

ix) arylthio -S-Ph,

x) aryloxy such as phenoxy -OPh

xi) -NHCOR₂

xii) -OCOR₂

xiii) -SCOR₂

xiv) -NHCONHR₂

xv) -NHCSNHR₂

xvi) -NHS0₂R₂

xvii) -OS0₂R₂

xviii) -SOR₂

xix) -S0₂R₂

xx) -S0₂NHR₂

xxi) piperidino which may be functionalized with one or more -CONH₂, Ci-C₆ alkyl which may be functionalized with a hydroxyl or Ci-C₆ N-alkylimidazolium radical, - a pyrrolidino radical which may be functionalized with one or more hydroxyl, Ci-C₆ alkyl, -NHR₂, amino, CrC₆ trialkylammonium, CrC₆ N-alkylimidazolium or (di)(Cr C₆)alkylamino radicals,

xxii) piperazino which may be functionalized with one or more Ci-C₆ alkyl radicals, xxiii) Ci-C₆ N,N dialkylpiperazinium

xxiv) diazepane

xxv) morpholino

xxvi) azepane

xxvii) -C0₂R₂

xxviii) -SO₃R2

xxix) -CONHR2

xxx) nitrile (-CN)

xxxi) -NHC0₂R₂

xxxii) -COR₂

xxxiii) -NHCNHNH₂

• - a phenyl radical; R₂ represents i) a hydrogen atom, ii) a C Ci₂ alkyl radical, iii) a phenyl radical, or iv) a 4-methylphenyl radical;

• n represents an integer between 1 and 6,

· Y represents a carbon atom or a nitrogen atom

• Z represents i) a carbon atom, ii) an oxygen atom, iii) a nitrogen atom, iv) a radical -IMR₃ in which R₃ represents:

- a hydrogen atom

- a Ci-C₆ alkyl radical which may optionally be substituted with one or more hydroxyl, CrC₆ alkoxy, amino, CrC₆ alkylamino, carboxylic (-C0₂H) or sulfonic (-SO₃H) radicals;

it being understood that:

- when n is greater than or equal to two, the radicals Ri are identical or different;

- when the compounds of formulae (I) to (III) comprise a cationic group, it is combined with an anionic counterion to achieve the electrical neutrality of the molecule,

- the compounds of formula (I) contain at least three substituents chosen from X and Ri which are electron-donating via the mesomeric effect (+M);

- the compounds of formula (II) or (III) contain at least two substituents chosen from X and Ri which are electron-donating via the mesomeric effect (+M);

- for formula (II), X or R-i are bonded to the carbon atoms 1 to 4 or 6 to 9;

- for formula (III), X or R-i are bonded to the carbon atoms 1 , 2 and 5 to 8 or to a carbon or nitrogen atom 3. Preferably, the compounds of formulae (I) to (III) are such that Y represents a carbon atom. According to an advantageous variant, the self-oxidizing compounds are of formula (III) and are particularly such that Z in position 1 or 2 represents a carbon atom and Z in position 3 represents a nitrogen atom.

In particular, in formulae (I) to (III), n is greater than or equal to 1 and Ri represents, independently of the other radicals Ri that may be present, i) a hydroxyl radical, ii) an amino radical, iii) a (di)(Ci-Ci₂)alkylamino radical which may be optionally substituted with one or more radicals a) to ag) as defined for the substituent R-i, iii) above, iv) a Ci-C₆ alkyloxy radical which may be optionally substituted with one or more radicals a) to ag) as defined for the substituent R-i, iii) above; the alkyl chain of the alkoxy possibly being interrupted with one or more oxygen atoms.

Preferentially, in the formulae (I), n is greater than or equal to 2 and Ri represents, independently of the other radicals Ri that may be present, i) a hydroxyl radical, ii) a (di)(Ci-Ci₂)alkylamino radical in which the alkyl groups may be optionally substituted with one or more radicals a) to ag) as defined for the substituent R-i, iii) above;

- a Ci-C₆ alkyloxy radical which may be optionally substituted with one or more radicals a) to ag) as defined for the substituent R-i, iii) above, the alkyl chain of the alkoxy possibly being interrupted with one or more oxygen atoms.

Preferably, R₂ represents a hydrogen atom or a Ci-C₆ alkyl, phenyl or 4-methylphenyl group.

Preferentially, the self-oxidizing compounds of the invention are of formula (I) as defined previously and more particularly benzene compounds and comprise a group X amino, or (di)(Ci-C₆)alkylamino in which the alkyl or the two alkyl groups are optionally substituted with one or more radicals chosen from hydroxyl, (CrC₆)alkoxy, (di)(Cr C₆)(alkyl)amino and cationic (hetero)aryl such as imidazolium.

As examples of the self-oxidizing compounds of the invention of formulae (I) to (III), mention may be made of those having the following formulae:

1 2 3 4

More preferentially, the self-oxidizing compounds of the invention are chosen from the following derivatives: a) monocyclic benzene compounds comprising at least three electron-donating substituents (or electron donors via +M effect) of which at least two of the said electron- donating substituents are contiguous (i.e. they are ortho to each other), the said substituents preferably being chosen from hydroxyl, (di)(Ci-C₆)(alkyl)amino and (d- C₆)alkoxy, the alkyl groups being optionally substituted with a hydroxyl or imidazolium group; in particular chosen from amino and hydroxyl, and

b) indole or indoline compounds substituted in positions 5 and 6 or 7 with two groups chosen from hydroxyl and amino and optionally substituted with one or two (CrC₆)alkyl groups in position 2 and/or 3 such as the compounds 44 to 54 above.

More particularly, the colouring agent(s) are chosen from the poly (I) compounds with (I) as defined previously, especially poly(2,3-diaminophenol), poly(2,6-diaminobenzene- 1 ,4-diol) and poly(2,4-diaminophenol), and the poly (III) compounds with (III) as defined previously, especially poly(5,6-dihydroxyindoline) and poly(5-amino-2,3-dimethyl-1 /-/-indol- 6-ol). ii) radical initiators or chemical oxidizing agents The process for preparing the colouring agent(s) uses as ingredient ii) one or more radical initiators and/or one or more chemical oxidizing agents. It is understood that the ingredient ii) is other than hydrogen peroxide. The term "and/or" means that the ingredient comprises one or more radical initiators alone, or one or more chemical oxidizing agents other than hydrogen peroxide, alone, or comprises one or more radical initiators with one or more chemical oxidizing agents; or alternatively that ingredient ii) has radical-initiating nature and also chemical oxidizing-agent nature.

The term "chemical oxidizing agent" means an oxidizing agent other than atmospheric oxygen and which is not of enzymatic origin.

According to a particular embodiment of the invention, the process for preparing the colouring agent(s) uses one or more ingredients ii) chosen from radical initiators.

The term "radical initiator" means any chemical compound that can generate a radical compound under mild conditions, and which induces a radical reaction (see, for example, J. March, Advanced Organic Chemistry, reactions, mechanisms, and structure, 4^th Ed., John Wiley & Sons, 1992, Chap. 14: Free-radical substitution).

In particular, these initiators comprise a weak bond, i.e. a bond with a low dissociation energy. Mention may typically be made of halo, azo or organic peroxide initiators. They may be generated thermally, at room temperature (25°C) or at higher temperature or photochemically.

These radical initiators are other than hydrogen peroxide. Free-radical initiators generated thermally or from light sources are intended in particular (see for example Macromol. Rapid Commun. Christian Decker, 23, 1067-1093 (2002); Encyclopedia of Polymer Science and Technology, "photopolymerisation free radical" http://onlinelibrary.wiley.com/doi/10.1002/0471440264.pst490/pdf; ibid,

"photopolymerization, cationic",

http://onlinelibrary.wiley.com/doi/10.1002/0471440264.pst491/pdf; Macromol. Symp. 143, 45-63 (1999)). Two major families may be distinguished:

- those of type I in which the radical initiators bring about, under irradiation or heat, a unimolecular cleavage of the covalent bond to give a free radical compound also symbolized by a "point", and

- those of type II in which the radical initiators lead to a bimolecular reaction in which the photoactive compounds in their excited state interact with a second molecule (or co- initiator) to generate free radicals.

More particularly, the radical initiators are chosen from the compounds of formula (V) and (VI), and also organic or mineral acid salts thereof, optical or geometrical isomers or tautomers thereof, and solvates thereof such as the hydrates:

(V) (VI)

in which formula (V) or (VI):

R¹, R², R³ and R⁴, which may be identical or different, represent a hydrogen atom or an optionally substituted linear or branched (CrC₈)alkyl or linear or branched (C C₈)alkoxy group; an optionally substituted aryl group such as phenyl;

or alternatively Ri and R₂ and/or R₃ and R₄ form, together with the carbon atoms that bear them, a 3- to 7-membered optionally substituted (hetero)cycloalkyl, particularly (C₃-C₆)cycloalkyl such as cyclohexyl;

preferably, R¹, R², R³ and R⁴, which may be identical or different, represent a hydrogen atom or a linear or branched (CrC₆)alkyl group;

x and y, which may be identical or different, represent an integer inclusively between 0 and 6 inclusively, and preferably x and y = 0;

• EW and EW\ which may be identical or different, preferably identical, represent an electron-withdrawing group, which is preferably electron-withdrawing via a mesomeric effect -M, such as cyano, -C(X¹)-X²-R_a, phosph(on)ate, sulf(on)ate, nitro or nitroso; more particularly EW = EW = cyano;

• R and R', which may be identical or different, preferably identical, represent i) a radical EW or EW' as defined previously, or a group chosen from ii) optionally substituted linear or branched (CrC₈)alkyl, iii) optionally substituted aryl, iv) optionally substituted aryl(CrC₈)alkyl,

or alternatively R with R-i and/or R' with R₃ form, together with the carbon atom that bears them, a group C(X¹) and R₂ and R₄ being as defined previously or R₂ and R₄, which may be identical or different, represent a group R⁵-(X²)_W- in which w is 0 or 1 ,

R₅ represents a hydrogen atom, a linear or branched (CrC₈)alkyl group, an optionally substituted (hetero)aryl group such as phenyl or a (hetero)cycloalkyl group optionally substituted especially with a (CrC₆)alkyl group such as cyclohexyl optionally substituted with a (CrC₆)alkyl group and X² is as defined below;

· X_a, which may be identical or different, represent a heteroatom chosen from oxygen and sulfur, a group -C(0)-0- or -O-C(O)-, a group -0-C(0)-0- or -0-C(0)-0-; preferably, X_a represent an oxygen atom;

X¹ and X², which may be identical or different, represent a heteroatom chosen from oxygen, sulfur and amino N(R") with R" being a hydrogen atom or a linear or branched (CrC₆)alkyl group; preferably, X¹ and X² represent an oxygen atom;

Mention may also be made of diatomic halogen molecules such as Cl₂ which will generate as radical initiator a halogen radical CI CI ) ; azo initiators of the type R-N=N-

R' which generate the radicals R and R' R and R' ) via elimination of gas N₂ such as AIBN (AzobislsoButyroNitrile) and ABCN (1 ,1'-AzoBis(CyclohexanecarboNitrile) which generate as radical isobutyronitrile and cyclohexanecarbonitrile , respectively.

According to a particular embodiment of the invention, the radical initiator(s) are chosen from organic peroxides, especially those of formula (VI) as defined previously. These peroxides comprise at least one -O-O- bond which cleaves readily into two radicals -O . Mention may be made more particularly of those having the following general formulae:

R_a-C(R'_aR'_b)-0-0-C(R'_aR'_b)-R_b (V ) or

R_c-(0)_s-0-C(R'_aR'_b)-0-0-C(R'_aR'_b)-0-(0)_s-R_d (VI₂) in which formulae (V ) and (Vl₂):

^■ R_a, R_b, R'a and R'_b, which may be identical or different, represent an optionally substituted (Ci-Ci₀)alkyl group, preferably (CrC₆)alkyl; optionally substituted

(hetero)aryl group such as phenyl; optionally substituted (hetero)cycloalkyl group such as cyclohexyl optionally substituted with (Ci-C₄)alkyl groups;

or alternatively R'_a and R'_b form, together with the carbon atom that bears them, a (thio)carbonyl group, preferably carbonyl;

■ R_c and R_d, which may be identical or different, represent a hydrogen atom or a group as defined for R_a or R_b; preferably, R_c and R_d represent a hydrogen atom or a cycloalkyl group such as cyclohexyl optionally substituted with a (CrC₆)alkyl group;

^■ X_a and X_b, which may be identical or different, represent a heteroatom such as an oxygen or sulfur atom, preferably oxygen; and

■ s is 0 or 1 .

According to one embodiment, the radical initiators have the formula below:

According to a particular embodiment of the invention, the radical initiator is AIBN

(azobisisobutyronitrile). This initiator generates free radicals i) under the influence of heat at a temperature of greater than or equal to 45°C, preferentially at a temperature of greater than or equal to 55°C, more particularly at 60°C; and/or ii) photochemically.

According to another particular embodiment of the invention, the radical initiator is

ABDV (2,2'-azobis(2,4-dimethylvaleronitrile)). This agent may be used under thermally "milder" polymerization conditions. Preferentially, when ABDV is used, the polymerization process is performed at a temperature of greater than or equal to 28°C and preferentially at a temperature of greater than or equal to 35°C, such as at 40°C.

According to another particular embodiment of the invention, the process for preparing the colouring agent(s) uses one or more ingredients ii) chosen from chemical oxidizing agents.

The term "chemical oxidizing agent" means an agent other than atmospheric oxygen which has the property of being able to oxidize the molecules, i.e. removing an electron from a molecule.

According to a particularly advantageous embodiment, the ingredient(s) ii) are chosen from the persulfates of formula

in which formula (VII) M⁺ represents a mineral or organic cationic counterion, chosen in particular from cations of alkali metals such as sodium or potassium, or of alkaline-earth metals, and ammonium R^aR^bR^cR^dN⁺ with R^a, R^b, R^c and R^d, which may be identical or different, representing a hydrogen atom or a (CrC₆)alkyl group such as NH₄ ⁺. In particular, the ingredient(s) ii) are chosen from:

the organic or mineral persulfates of formula (VII) such as ammonium persulfates; organic peroxides such as di-tert-butyl peroxide, dicumyl peroxide, benzoyl peroxide (BPO) or methyl ethyl ketone peroxide (MEKP);

azo compounds such as 2,2'-azobisisobutyronitrile (AIBN) or 1 ,1 -azobis (cyclohexanecarbonitrile) (ABCN); and the products of reaction:

^■ between hydrogen peroxide and ascorbic acid

^■ between hydrogen peroxide and metal salts, especially metal salts of transition metals such as Fe, especially metal salts of Fe²⁺;

■ between organic peroxides such as ammonium persulfate and metabisulfites;

alkali metal or alkaline-earth metal dichromate such as sodium dichromate;

copper halides, in particular of Cu(ll) such as CuCI₂;

the product of reaction between hydrogen peroxide and ascorbic acid; and

the product of reaction between hydrogen peroxide and metal salts such as Fe²⁺ (Fenton reaction).

Preferably, the ingredient(s) ii) are chosen from the persulfates of formula ((VII) as defined previously, in particular persulfates with organic cationic counterions such as those in which M⁺ represents an ammonium group R^aR^bR^cR^dN⁺ with R^a, R^b, R^c and R^d, which may be identical or different, representing a hydrogen atom or a (CrC₆)alkyl group such as NH₄ ⁺.

Process for preparing the colouring agent(s): Preferably, the colouring agent(s) of the invention are prepared by polymerization of the self-oxidizing compounds i) as defined previously in the presence of radical initiators or chemical oxidizing agents ii) as defined previously at a temperature between 0°C and 80°C and more particularly between 0°C and 35°C. According to another particular preparation embodiment, colouring agents of the invention are prepared from self-oxidizing compounds i) as defined previously, photoactive radical initiators as ingredients ii) in the presence of one or more identical or different light sources. The said light source(s) photo-irradiate by electromagnetic waves with wavelengths within the UV range up to the IR range.

The term "photoirradiation with an electromagnetic wave" means any exposure of the composition or part of the composition to a light wave during the hair dyeing process. The light spectrum may comprise wavelengths within the UV region (200-400 nm), the visible region (400-750 nm) and the infrared region (745 nm to 3 μηη).

Ultraviolet radiation, visible light or infrared radiation may be used. The choice depends on the characteristic absorption of the photoactive radical initiator. If the photoactive radical initiator absorbs in ultraviolet wavelengths, then ultraviolet radiation is used to activate it. If the photoactive radical initiators absorb in the visible wavelengths, then visible radiation is used. The absorption spectra of the photoactive radical initiators are available in the literature.

The amount of light energy varies as a function of the photoactive radical initiators. Light energy sufficient to activate the said photoactive initiator simply suffices. Occasionally, daylight suffices. According to a specific form of the invention, the dyeing process takes place in natural sunlight or natural daylight.

According to another process for preparing the colouring agents of the invention, the source of the photoirradiation is artificial. For the lamps emitting in the UV range, mention may be made of those described in Ullmann's Encyclopedia "Ultraviolet and Visible Spectroscopy" 2008, Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, 10.1002/14356007. b05 383.pub2, point 3.2. For the lamps in general, mention may be made of those mentioned in Ullmann's Encyclopedia "Lamps" 2005, Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim 10.1002/14356007.a15 1 15, and Ullmann's Encyclopedia "Photochemistry" 2005, Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim 10.1002/14356007.a19 573, point 3.2 "light sources".

The lamps used in the process of the invention are in particular incandescent, halogen, fluorescent, mercury or low-pressure lamps, low-pressure lamps, for example sodium or neon lamps, high-pressure lamps, for example mercury lamps, halide lamps, flash lamps, for example xenon flash lamps, fluorescent excimer lamps, such as xenon fluorescent excimer lamps, Light Emitting Diodes or LEDs of 0.01 to 1000 mW, lamps emitting black light or Wood's light, and lasers. Preferentially, the artificial sources originate from mercury lamps, tungsten halogen lamps, white neon tubes, LEDs or UV lamps emitting at 254 nm or at 365 nm.

According to an advantageous embodiment of the invention, the process for preparing the colouring agents involves a first step in which the self-oxidizing compounds i) as defined previously are dissolved in a liquid solution, preferably in an aqueous-alcoholic solution, and then, in the second step, one or more alkaline agents as defined previously are added, especially with aqueous ammonia to give a basic pH preferably of between 8 and 10, and then, in a third step, the radical initiator(s) ii) as defined previously are added, in particular persulfates of formula (VII), more particularly those with organic cationic counterions such as those in which M⁺ represent an ammonium group R^aR^bR^cR^dN⁺ with R^a, R^b, R^c and R^d, which may be identical or different, representing a hydrogen atom or a (C C₆) alkyl group such as NH₄ ⁺ as defined previously. In particular, the preparation process is performed at room temperature (25°C). According to a particular embodiment, the preparation process is performed with stirring for between 30 minutes and 2 days and preferentially between 1 hour and 3 hours. According to a variant, during a fourth step, the precipitate formed is filtered off, washed, preferably with water, and then dried, preferably under vacuum.

Preferably, the amount of i) and ii) respect a weight ratio i) of the self-oxidizing compound(s)/ii) of the radical initiator(s) or of the chemical oxidizing agent(s) of between 0.5 and 1.5, and more particularly the ratio is 1 . Colouring agents - coloured oligomers or polymers:

According to one embodiment of the invention, the colouring agent(s) are obtained from the polycondensation i) of the self-oxidizing compounds as defined previously that react together in the presence ii) of at least one radical initiator or of at least one chemical oxidizing agent as defined previously.

More particularly, the colouring agent(s) are chosen from the poly (I) compounds with (I) as defined previously, especially poly(2,3-diaminophenol), poly(2,6-diaminobenzene- 1 ,4-diol) and poly(2,4-diaminophenol), and the poly (III) compounds with (III) as defined previously, especially poly(5,6-dihydroxyindoline) and poly(5-amino-2,3-dimethyl-1 /-/-indol- 6-ol).

Another subject of the invention is a colouring agent that may be obtained by chemical polycondensation: i) of self-oxidizing compounds with each other as defined previously in the presence of at least one ingredient ii) chosen from radical initiators and chemical oxidizing agents as defined previously, preferably with a weight ratio of i)/ii) between 0.5 and 1 .5, and more particularly the ratio is 1. Another subject concerns the use of a colouring agent, preferably a pigment, as defined previously for colouring keratin materials.

The composition of the invention Another subject of the invention is a composition comprising at least one colouring agent as defined previously.

Preferably, the composition of the invention does not comprise any oxidation base and/or hydrogen peroxide. More preferentially, the colouring agent included in the composition is prepared respecting a weight ratio i) of the self-oxidizing compound(s)/ii) of the radical initiator(s) or of the chemical oxidizing agent(s) of between 0.5 and 1.5, and more particularly the ratio is 1.

The cosmetic medium:

The term "cosmetic medium" means a medium that is suitable for dyeing keratin materials, also known as a dye support, which is a cosmetic medium generally formed from water or a mixture of water and one or more organic solvents or a mixture of organic solvents. Preferably, the composition comprises water in a content especially inclusively between 5% and 95% relative to the total weight of the composition. The term "organic solvent" means an organic substance that is capable of dissolving another substance without chemically modifying it.

Organic solvents:

Examples of organic solvents that may be mentioned include Ci-C₄ lower alkanols, such as ethanol and isopropanol; polyols and polyol ethers, for instance 2-butoxyethanol, propylene glycol, propylene glycol monomethyl ether, diethylene glycol monoethyl ether and monomethyl ether, and also aromatic alcohols, for instance benzyl alcohol or phenoxyethanol, and mixtures thereof.

The organic solvents are preferably present in proportions preferably inclusively between 0.1 % and 40% by weight approximately relative to the total weight of the dye composition, more preferentially between 1 % and 30% by weight approximately and even more preferentially inclusively between 5% and 25% by weight relative to the total weight of the composition.

The composition according to the invention contains, in a cosmetic medium, an amount of colouring agent as defined previously, generally inclusively between 0.001 % and 30% relative to the total weight of the composition.

Preferably, the amount of colouring agent of the invention is inclusively between 0.01 % and 5% by weight relative to the total weight of the composition. By way of example, the dye(s) are in an amount of between 0.01 % and 2%.

Preferably, the composition of the dyeing process of the invention is in liquid form and contains one or more colouring agents as defined previously.

Alkaline agents:

The dyeing process may use one or more alkaline agents. More particularly, the composition of the invention may also comprise one or more alkaline agents. This agent may be chosen from mineral or organic or hybrid alkaline agents, or mixtures thereof.

The mineral alkaline agent(s) are preferably chosen from aqueous ammonia, alkali metal carbonates or bicarbonates such as sodium or potassium carbonates and sodium or potassium bicarbonates, sodium hydroxide or potassium hydroxide, or mixtures thereof.

According to an advantageous embodiment of the invention, the alkaline agent(s) are organic amines, i.e. they contain at least one substituted or unsubstituted amino group.

The organic alkaline agent(s) are preferably chosen from organic amines with a pK_b at 25 °C of less than 12, preferably less than 10 and even more advantageously less than 6. It should be noted that it is the pK_b corresponding to the function of highest basicity.

Hybrid compounds that may be mentioned include the salts of the amines mentioned previously with acids such as carbonic acid or hydrochloric acid. The organic alkaline agent(s) are chosen, for example, from alkanolamines, oxyethylenated and/or oxypropylenated ethylenediamines, amino acids and the compounds of formula (VIII) below:

^R \ / ^RZ

N - W - N

^{K K} (VIII)

in which formula (VIII):

• W is a divalent Ci-C₆ alkylene radical optionally substituted with a hydroxyl group or a Ci-C₆ alkyl radical, and/or optionally interrupted with one or more heteroatoms such as oxygen or NR^U;

• R^x, R^y, R^z, R* and R^u, which may be identical or different, represent a hydrogen atom or a CrC₆ alkyl, CrC₆ hydroxyalkyl or CrC₆ aminoalkyl radical.

Examples of such amines that may be mentioned include 1 ,3-diaminopropane, 1 ,3- diamino-2-propanol, spermine and spermidine.

The term "alkanolamine" is intended to mean an organic amine comprising a primary, secondary or tertiary amine function, and one or more linear or branched CrC₈ alkyl groups bearing one or more hydroxyl radicals.

The composition of the invention preferably contains one or more alkanolamines. Even more preferentially, the organic amine is monoethanolamine.

In one variant of the invention, the composition comprises, as alkaline agent, one or more alkanolamines (preferably ethanolamine) and aqueous ammonia. In this variant, the alkanolamine(s) are present in a predominant amount relative to the aqueous ammonia.

According to another variant, the dye composition comprises aqueous ammonia.

Advantageously, the composition according to the invention has a content of alkaline agent(s) ranging from 0.01 % to 30% by weight, preferably from 0.1 % to 20% by weight and better still from 1% to 10% by weight relative to the weight of the said composition.

Adjuvants:

The composition comprising the colouring agent(s) as defined previously may also contain various adjuvants conventionally used in hair dye compositions, such as anionic, cationic or nonionic surfactants, or mixtures thereof, anionic, cationic, nonionic, amphoteric or zwitterionic polymers or mixtures thereof, mineral or organic thickeners, penetrants, sequestrants, fragrances, buffers, dispersants, conditioning agents, for instance volatile or non-volatile, modified or unmodified silicones, film-forming agents, ceramides, preserving agents and opacifiers.

The above adjuvants are generally present in an amount, for each of them, of between 0.01% and 20% by weight, relative to the weight of the composition.

Needless to say, a person skilled in the art will take care to select this or these optional additional compound(s) such that the advantageous properties intrinsically associated with the dye composition in accordance with the invention are not, or are not substantially, adversely affected by the envisaged addition(s).

Additional dyes:

The composition comprising the colouring agent(s) as defined previously of the process of the invention may also contain one or more additional direct dyes. These direct dyes are chosen, for example, from those conventionally used in direct dyeing, and among which mention may be made of any commonly used aromatic and/or non-aromatic dyes such as neutral, acidic or cationic nitrobenzene direct dyes, neutral, acidic or cationic azo direct dyes, natural direct dyes, neutral, acidic or cationic quinone and in particular anthraquinone direct dyes, azine, triarylmethane, indoamine, methine, styryl, porphyrin, metalloporphyrin, phthalocyanine, cyanine and methine direct dyes, and fluorescent dyes.

Among the natural direct dyes, mention may be made of lawsone, juglone, alizarin, purpurin, carminic acid, kermesic acid, purpurogallin, protocatechaldehyde, indigo, isatin, curcumin, spinulosin, apigenidin and orceins. Use may also be made of extracts or decoctions containing these natural dyes and in particular henna-based poultices or extracts.

According to the invention, the additional direct dye(s) used according to the invention preferably represent from 0.001 % to 10% by weight approximately relative to the total weight of the dye composition comprising the colouring agent(s) as defined previously and even more preferentially from 0.05% to 5% by weight approximately. pH:

The pH of the composition according to the invention is generally inclusively between 2 and 12 approximately and preferably between 3 and 1 1 approximately. It may be adjusted to the desired value by means of acidifying or basifying agents usually used in the dyeing of keratin fibres, or alternatively using standard buffer systems.

The pH of the composition is preferentially inclusively between 6 and 1 1 , particularly between 7 and 10.5, and more particularly between 8 and 10, such as 9.5.

Among the acidifying agents that may be mentioned, for example, are mineral or organic acids, for instance hydrochloric acid, orthophosphoric acid, sulfuric acid, carboxylic acids, for instance acetic acid, tartaric acid, citric acid and lactic acid, and sulfonic acids.

Among the alkaline agents, examples that may be mentioned include aqueous ammonia, alkali metal carbonates, alkanolamines such as monoethanolamine, diethanolamine and triethanolamine, and other standard alkaline agents used in cosmetics for hair dyeing, as defined previously.

Forms of the composition: The dye composition comprising the colouring agent(s) as defined previously may be in various galenical forms, such as in the form of liquids, lotions, creams or gels, or in any other form that is suitable for dyeing keratin materials. They may also be conditioned under pressure in an aerosol can in the presence of a propellant or in a non-aerosol can, and form a mousse.

Dyeing processes of the invention:

The process for dyeing keratin materials of the invention uses at least one colouring agent, preferably a colouring agent that may be obtained from the polycondensation i) of self-oxidizing compounds in the presence ii) of at least one radical initiator as defined previously. More precisely, the colouring agent(s) are applied to the keratin materials. Preferably, the colouring agent(s) are in a cosmetic composition as defined previously, which is applied to the keratin materials.

The leave-on time of the dye composition, i.e. the composition comprising the colouring agent(s) as defined previously, is inclusively between 5 minutes and 1 hour and preferably between 10 minutes and 40 minutes.

According to a particular embodiment of the invention, the dyeing process comprises the following steps:

1 ) a composition comprising at least one colouring agent as defined previously is applied to the keratin materials; and then

2) the dye composition is left to stand on the keratin materials for a time inclusively between 5 minutes and 1 hour and preferably between 10 minutes and 40 minutes; and then

3) the keratin materials are optionally shampooed with a standard shampoo and/or rinsed and dried. The dye composition, i.e. the composition comprising the colouring agent(s), is generally applied at room temperature. However, it may be applied at temperatures ranging from 20 to 180°C.

The dyeing process according to the invention may be followed by shampooing with a standard shampoo and/or drying of the keratin materials.

The examples that follow serve to illustrate the invention without, however, being limiting in nature. EXAMPLES OF DYEING

SYNTHESIS OF THE COLOURING AGENTS: Compound 1 : Synthesis of poly(2,3-diaminophenol)

620.7 mg (5 mmol) of 2,3-diaminophenol are dissolved in 20 ml of ethanol. The pH is then brought to 10 by adding a few drops of 20% aqueous ammonia solution.

1 141 mg (5 mmol) of ammonium persulfate dissolved in 3 ml of water are then added dropwise over 10 minutes.

The reaction medium is stirred at room temperature for 1 hour 15 minutes. The precipitate is filtered off, washed with water and then dried under vacuum.

HPLC/HRMS analysis performed on an Accela chain coupled to an LTQ-Orbitrap (Thermo Fisher) high-resolution mass spectrometer (HRMS) allows detection of the following ions:

Compound 2: Synthesis of poly(2,6-diaminobenzene-1 ,4-diol)

1065 mg (5 mmol) of 2,6-diaminobenzene-1 ,4-diol dihydrochloride are dissolved in 10 ml of ethanol and 3 ml of water. The pH is then brought to 9.9 with 20% aqueous ammonia solution. 1 141 mg (5 mmol) of ammonium persulfate dissolved in 3 ml of water are then added dropwise over 7 minutes.

The reaction medium is stirred at room temperature for 2 hours; the pH is at 9.5 before filtration.

The precipitate is filtered off, washed with water and dried under vacuum.

HPLC/HRMS analysis performed on an Accela chain coupled to an LTQ-Orbitrap (Thermo Fisher) high-resolution mass spectrometer (HRMS) allows detection of the following ions: tR (min) m/z Empirical formula

20 433+ C24H12N6O3 Compound 3: Synthesis of poly(5,6-dihydroxyindoline)

928 mg (4 mmol) of 5,6-dihydroxyindoline are dissolved in 4 ml of ethanol and 12 ml of water, and the pH is brought to 10 with 20% aqueous ammonia solution. 913 mg (4 mmol) of ammonium persulfate dissolved in 3 ml of water are then added dropwise.

The reaction medium is stirred at room temperature for 5 hours.

After filtering off by suction the brown precipitate formed, washing with water and ethanol and drying, 401 mg of brown powder are obtained. Compound 4: Synthesis of poly(5-amino-2,3-dimethyl-1 /-/-indol-6-ol)

1690 mg of 5-amino-2,3-dimethyl-1 /-/-indol-6-ol dihydrobromide are dissolved in a mixture of 20 ml of ethanol and 3 ml of water. The pH of this suspension is then brought to 1 1 with 20% aqueous ammonia solution to obtain dissolution of the indole. 1 141 mg of ammonium persulfate dissolved in 3 ml of water are then added dropwise over 5 minutes.

The reaction medium is stirred at room temperature for 7 hours. The precipitate is filtered off, washed with water and dried under vacuum in the presence of P2O₅.

The molecular ion 349 (ES+) is detected by mass spectrometry. Compound 5: Synthesis of poly(2,4-diaminophenol)

985 mg of 2,4-diaminophenol dihydrochloride are dissolved in 10 ml of ethanol and 3 ml of water in a round-bottomed flask. The pH is then brought to 9.9 with 20% aqueous ammonia solution; the medium darkens. 1 141 mg of ammonium persulfate dissolved in about 3 ml of water are then added dropwise at room temperature over 14 minutes.

The mixture is then left for 3 hours at room temperature; the pH remains at about 9.5. The precipitate is filtered off, rinsed with water and dried under vacuum. 561 mg of black powder are obtained.

II) EVALUATION ON KERATIN FIBRES

A formulation support is prepared by mixing, respectively:

- 0.5 g of benzoic acid

- 5 g of benzyl alcohol

- 15 g of ethanol - water to obtain 100 g of mixture

- 20% aqueous ammonia to obtain a pH of 9.5.

0.5 g of coloured oligomers is added to this formulation support and the resulting mixture is then applied to locks of natural hair containing 90% white hairs (liquor/hair ratio 5/1 ) for 30 minutes at 20°C. The locks are then washed and shampooed.

Calculation of the colour variation ΔΕ^*

The coloration build-up (ΔΕ^*) also called uptake was evaluated in the CIE L^* a^* b^* system. In this L^* a^* b^* system, L^* represents the intensity of the colour, a^* indicates the green/red colour axis and b^* indicates the blue/yellow colour axis. The lower the value of L^*, the darker or more intense the colour.

The value of ΔΕ^* was calculated from the values of L^*a^*b^* according to equation (i) below: Δ _ab * = V(L* - L₀ *)² + (a* - a₀ *)² + (b* - b₀ *)²

The coloration build-up (ΔΕ^*) was calculated on the locks of untreated hair (L₀ ^*, a₀ ^* and bo*) and on locks of dyed hair (L^*, a^* and b^*).

The greater the value of ΔΕ^*, the better the coverage of the fibres.

Claims

1. Process for dyeing keratin materials, especially keratin fibres, in particular human keratin fibres such as the hair, using at least one colouring agent, obtained from polycondensation between i) several self-oxidizing compounds that react together in the presence of one or more ingredients ii) chosen from radical initiators and chemical oxidizing agents other than hydrogen peroxide.

2. Process according to the preceding claim, in which the self-oxidizing compounds

(I) (ll) (Ml)

in which formulae (I) to (III):

• represents a single bond or a double bond;

• X represents i) an amino radical, ii) a Ci-C₆ (di)alkylamino radical which may optionally be substituted with one or more hydroxyl, Ci-C₆ alkoxy, amino, Ci-C₆ alkylamino, carboxylic (-C0₂H) or sulfonic (-S0₃H) radicals; iii) a hydroxyl radical;

• Ri represents a radical covalently bonded to a carbon atom, chosen from:

i) hydroxyl,

ii) thiol -SH,

vii) halogen

viii) -NHPh

ix) arylthio -S-Ph,

x) aryloxy such as phenoxy -OPh

xi) -NHCOR₂

xii) -OCOR₂

xiii) -SCOR₂

xiv) -NHCONHR₂

XV) -IMHCSNHR2

xvi) -NHS0₂R₂

xviii) -SOR₂

xxi) piperidino which may be functionalized with one or more -CONH₂, Ci-C₆ alkyl which may be functionalized with a hydroxyl or Ci-C₆ N-alkylimidazolium radical,

- a pyrrolidino radical which may be functionalized with one or more hydroxyl, Ci-C₆ alkyl, -NHR₂, amino, CrC₆ trialkylammonium, CrC₆ N-alkylimidazolium or (di)(Cr C₆)alkylamino radicals,

xxiv) diazepane

xxv) morpholino

xxvi) azepane

xxvii) -CO2R2

xxviii) -SO₃R2

xxix) -CONHR₂

xxx) nitrile (-CN)

xxxi) -NHC0₂R₂

xxxii) -COR₂

xxxiii) -NHCNHIMH2

- a phenyl radical; R₂ represents i) a hydrogen atom, ii) a C₁-C₁₂ alkyl radical, iii) a phenyl radical, or iv) a 4-methylphenyl radical;

n represents an integer between 1 and 6, • Y represents a carbon atom or a nitrogen atom

• Z represents i) a carbon atom, ii) an oxygen atom, iii) a nitrogen atom, iv) a radical -NR₃ in which R₃ represents:

- a hydrogen atom

it being understood that:

- for formula (II), X or R-i are bonded to the carbon atoms 1 to 4 or 6 to 9;

- for formula (III), X or R-i are bonded to the carbon atoms 1 , 2 and 5 to 8 or to a carbon or nitrogen atom 3.

3. Process according to the preceding claim, in which the self-oxidizing compounds are chosen from those of formulae (I) to (III) with Y representing a carbon atom and/or the self-oxidizing compounds of formula (III) with Z in position 1 or 2 representing a carbon atom and Z in position 3 representing a nitrogen atom.

4. Process according to any one of the preceding claims, in which the self- oxidizing compounds are chosen from a) monocyclic benzene compounds comprising at least three electron-donating substituents, of which at least two of the said electron- donating substituents are contiguous (i.e. they are ortho to each other), the said substituents preferably being chosen from hydroxyl, (di)(Ci-C₆)(alkyl)amino and (d- C₆)alkoxy, the alkyl groups being optionally substituted with a hydroxyl or imidazolium group; in particular chosen from amino and hydroxyl, and

b) indole or indoline compounds substituted in positions 5 and 6 or 7 with two groups chosen from hydroxyl and amino and optionally substituted with one or two (CrC₆)alkyl groups in position 2 and/or 3.

5. Process according to any one of the preceding claims, in which the self- oxidizing compounds are chosen from those having the formulae below, and also organic or mineral acid salts thereof, optical or geometrical isomers or tautomers thereof, and solvates thereof such as hydrates:

22 31

51 52 53

54 55 56

with An^" representing an anionic counterion such as halo, for instance CI^".

6. Process according to any one of the preceding claims, in which the ingredient(s) ii) are chosen from those having the formulae (V) to (VII) below, and also organic or mineral acid salts thereof, optical or geometrical isomers or tautomers thereof, and solvates thereof such as the hydrates:

(V) (VI)

in which formula (V) or (VI):

R¹, R², R³ and R⁴, which may be identical or different, represent a hydrogen atom or an optionally substituted linear or branched (CrC₈)alkyl or linear or branched (C

C₈)alkoxy group; an optionally substituted aryl group such as phenyl;

x and y, which may be identical or different, represent an integer inclusively between 0 and 6, and preferably x and y = 0;

• EW and EW, which may be identical or different, preferably identical, represent an electron-withdrawing group, which is preferably electron-withdrawing via a mesomeric effect -M, such as cyano, phosph(on)ate, sulf(on)ate, nitro or nitroso; more particularly EW = EW = cyano;

or alternatively R with R-i and/or R' with R₃ form, together with the carbon atom that bears them, a group C(X¹) and R₂ and R₄ being as defined previously or R₂ and R₄, which may be identical or different, represent a group R⁵-(X²)_W- in which w is 0 or 1 , R₅ represents a hydrogen atom, a linear or branched (CrC₈)alkyl group, an optionally substituted (hetero)aryl group such as phenyl or a (hetero)cycloalkyl group optionally substituted especially with a (CrC₆)alkyl group such as cyclohexyl optionally substituted with a (CrC₆)alkyl group and X² is as defined below;

• X_a, which may be identical or different, represent a heteroatom chosen from oxygen and sulfur, a group -C(0)-0- or -O-C(O)-, a group -0-C(0)-0- or -0-C(0)-0-; preferably, X_a represent an oxygen atom;

• X¹ and X², which may be identical or different, represent a heteroatom chosen from oxygen, sulfur and amino N(R") with R" being a hydrogen atom or a linear or branched (CrC₆)alkyl group; preferably, X¹ and X² represent an oxygen atom.

7. Process according to any one of the preceding claims, in which the ingredient(s) ii) are chosen from:

- organic or mineral persulfates, such as ammonium persulfates;

organic peroxides such as di-tert-butyl peroxide, dicumyl peroxide, benzoyl peroxide (BPO) or methyl ethyl ketone peroxide (MEKP);

azo compounds such as 2,2'-azobisisobutyronitrile (AIBN) or 1 ,1 '-azobis (cyclohexanecarbonitrile) (ABCN); and

- the products of reaction:

^■ between hydrogen peroxide and ascorbic acid,

^■ between organic peroxides such as ammonium persulfate and metabisulfites;

- alkali metal or alkaline-earth metal dichromates such as sodium dichromate; and

copper halides, in particular of Cu(ll) such as CuCI₂.

8. Process according to any one of the preceding claims, in which the ingredient(s) ii) are chosen from those of formula (VII) below:

O

Q o-s-o M'⁺

+ - " ' I I

M O— S-0

0 (VII)

in which formula (VII) M⁺ represents a mineral or organic cationic counterion, chosen in particular from cations of alkali metals such as sodium or potassium, or of alkaline-earth metals, and ammonium R^aR^bR^cR^dN⁺ with R^a, R^b, R^c and R^d, which may be identical or different, representing a hydrogen atom or a (CrC₆)alkyl group such as NH₄ ⁺.

9. Process according to any one of the preceding claims, in which the colouring agent(s) are prepared according to a process including:

in the first step, dissolving the self-oxidizing compounds i) as defined in any one of Claims 1 to 5, in a liquid solution, preferably an aqueous-alcoholic solution; and then in the second step, adding one or more alkaline agents, especially with aqueous ammonia to achieve a basic pH preferably between 8 and 10, and then

in a third step, adding the ingredient(s) ii) as defined in any one of Claims 1 and 6 to 8; in particular, the preparation process is performed at room temperature (25°C) and with stirring for between 30 minutes and 2 days and preferentially between 1 hour and 3 hours; optionally

- in a fourth step, the precipitate formed is filtered off, washed, preferably with water, and then dried, preferably under vacuum.

10. Process according to any one of the preceding claims, in which the colouring agent(s) are prepared according to a process which uses an amount of self- oxidizing compound i) as defined in any one of Claims 1 to 5, and of ingredients ii) as defined in any one of Claims 1 and 6 to 8, respecting a self-oxidizing compound i)/ingredients ii) weight ratio of between 0.5 and 1.5, and in particular the ratio = 1 .

11. Process according to any one of the preceding claims, in which the colouring agent(s) are chosen from the poly (I) compounds with (I) as defined in any one of Claims 2 to 5, especially poly(2,3-diaminophenol), poly(2,6-diaminobenzene-1 ,4-diol) and poly(2,4-diaminophenol), and the poly (III) compounds with (III) as defined in any one of Claims 2 to 5, especially poly(5,6-dihydroxyindoline) and poly(5-amino-2,3-dimethyl-1 /-/- indol-6-ol).

12. Process according to any one of the preceding claims, in which the colouring process comprises the following steps:

1 ) a composition comprising at least one colouring agent as defined in any one of the preceding claims is applied to the keratin materials, in particular keratin fibres; and then

2) the dye composition is left to stand on the keratin materials, in particular keratin fibres, for a time inclusively between 5 minutes and 1 hour and preferably between 10 minutes and 40 minutes; and then

3) the keratin materials, in particular keratin fibres, are optionally shampooed with a standard shampoo and/or rinsed and dried.

13. Colouring agent obtained from the polycondensation i) of self-oxidizing compounds that react together as defined according to any one of Claims 1 to 5, in the presence ii) of at least one radical initiator as defined in any one of Claims 1 and 6 to 8; optionally prepared according to the process of Claim

14. Colouring agent as defined in the preceding claims, in which the colouring agent(s) are chosen from the poly (I) compounds with (I) as defined in any one of Claims 2 to 5, especially poly(2,3-diaminophenol), poly(2,6-diaminobenzene-1 ,4-diol) and poly(2,4-diaminophenol), and the poly (III) compounds with (III) as defined in any one of Claims 2 to 5, especially poly(5,6-dihydroxyindoline) and poly(5-amino-2,3-dimethyl-1 /-/- indol-6-ol).

15. Composition comprising at least one colouring agent as defined in Claim 14, preferably not comprising any oxidation base and/or chemical oxidizing agent.

16. Use of a colouring agent as defined in any one of Claims 1 to 12, 13 or 14, for dyeing keratin materials, in particular keratin fibres such as the hair, or the skin.