Hair dyeing process using a composition comprising a direct dye which is recirculated on the hair

Abstract

The invention relates to a process for dyeing keratin fibres, in particular human keratin fibres such as the hair, comprising: i) applying to said keratin fibres a dyeing composition (A) comprising one or more direct dyes and optionally water, ii) recovering at least one portion of the dyeing composition (A) after applying to said keratin fibres, iii) applying the dyeing composition (A) recovered in step ii) to the keratin fibres, iv) optionally rinsing said keratin fibres with water.

Description

Hair dyeing process using a composition comprising a direct dye which is recirculated on the hair

[0001] The present invention relates to a process for dyeing human keratin fibres, in particular the hair, using a dyeing composition comprising a direct dye which is recirculated on the hair.

[0002] It is known practice to dye keratin fibres, and in particular human hair, with compositions containing direct dyes, namely molecules with an affinity for the fibres and which colour even in the absence of an oxidizing agent added to the compositions containing them.

[0003] The direct dyes generally used are chosen from nitrobenzene, anthraquinone, nitropyridine, azo, methine, azomethine, xanthene, acridine, azine and triarylmethane direct dyes. The chemical species used may be nonionic, anionic (acidic dyes) or cationic (basic dyes). Direct dyes may also be natural dyes.

[0004] Compositions containing one or more direct dyes are applied to the keratin fibres for a time necessary to obtain the desired colouring, and are then rinsed out.

[0005] These compositions for direct dyeing of keratin fibres generally contain direct dyes combined with surfactants and / or thickeners to improve their application qualities.

[0006] However, the presence of certain ingredients in the compositions can reduce the effectiveness of the dyes, thus requiring the use of a large amount of dyes.

[0007] Moreover, the formulation of environmentally friendly cosmetic products, i.e. products whose design and development take account of environmental issues, is becoming a major preoccupation for contributing towards meeting the global challenges. It is therefore essential to provide more sustainable dyeing compositions and / or processes, thus enabling these environmental challenges to be met.

[0008] In this context, it is important to develop novel hair dyeing processes which require a reduced amount of compounds necessary for obtaining satisfactory colouring, in particular in order to limit the amount of compounds present in the rinsing waters.

[0009] There is therefore a real need to develop a process for dyeing keratin fibres using direct dyes which makes it possible to reduce the amount of direct dyes used, in particular in order to limit the amount of dye present in the rinsing waters, while obtaining a good colour build-up, intense and chromatic colours, and a good persistence with respect to shampoo washing.

[0010] These aims and others are achieved by the present invention, a subject of which is thus a process for dyeing keratin fibres, in particular human keratin fibres such as the hair, comprising:

[0011] i) applying to said keratin fibres a dyeing composition (A) comprising one or more direct dyes and optionally water,

[0012] ii) recovering at least one portion of the dyeing composition (A) after applying to the keratin fibres,

[0013] iii) applying the dyeing composition (A) recovered in step ii) to said keratin fibres,

[0014] iv) optionally, rinsing the keratin fibres with water.

[0015] The invention makes it possible to significantly reduce the amount of dye necessary for obtaining satisfactory colouring, in particular a good colour build-up, intensity and chromaticity of the colour, and uniform colouration.

[0016] The combination of direct dyes with application by a recirculation system makes it possible both to increase the colouring power and to reduce the compounds in the rinsing waters.

[0017] Other subjects, features, aspects and advantages of the invention will emerge even more clearly on reading the following description and examples and on examining the appended drawing, in which:

[0018] -schematically represents a dispensing device implementing the process of the invention.

[0019] In the text hereinbelow, unless otherwise indicated, the limits of a range of values are included in that range, notably in the expressions “between” and “ranging from ... to ...”.

[0020] Moreover, the expression “at least one” used in the present description is equivalent to the expression “one or more”.

[0021] The process of the invention uses a dyeing composition (A), optionally a pretreatment composition (B) and optionally a post-treatment composition (C).Dyeing composition (A)

[0022] The dyeing composition (A) used in the process of the invention comprises one or more direct dyes.

[0023] The term “direct dye” means a natural and / or synthetic dye, including in the form of an extract or extracts, other than oxidation dyes. These are coloured compounds that will spread superficially on the fibre. They may be ionic or nonionic, i.e. anionic, cationic, amphoteric or nonionic.

[0024] The dyeing composition (A) used in the process of the invention comprises one or more direct dyes.

[0025] “Direct dye” is understood to mean coloured species. These are dyes which will spread superficially on the fibre.

[0026] The direct dye(s) that may be used according to the invention are chosen from natural direct dyes, synthetic direct dyes, and mixtures thereof.

[0027] Preferably, the direct dye(s) that may be used according to the invention are chosen from ionic direct dyes and nonionic direct dyes, more particularly from cationic direct dyes, amphoteric direct dyes, anionic direct dyes, nonionic direct dyes, and mixtures thereof.

[0028] The direct dyes are chosen, for example, from nitrobenzene direct dyes, azo direct dyes, tetraazapentamethine dyes, quinone and in particular anthraquinone dyes, azine direct dyes, triarylmethane direct dyes, azomethine direct dyes and natural direct dyes.

[0029] The dyeing composition (A) may comprise one or more nonionic direct dyes.

[0030] Among the nonionic direct dyes, mention may be made of nonionic nitrobenzene direct dyes, nonionic azo direct dyes and nonionic anthraquinone dyes.

[0031] The dyeing composition (A) may comprise one or more cationic direct dyes.

[0032] “Cationic direct dye” is understood to mean any dye different from oxidation dyes, commonly referred to as “basic” direct dyes or “basic dyes”. They are referred to as “basic” because of their affinity for acidic substances, notably comprising at least one cationic or cationizable endocyclic or exocyclic group within their structure.

[0033] The cationic direct dye(s) contain at least one quaternized cationic chromophore or at least one chromophore bearing a quaternized or quaternizable cationic group.

[0034] According to a particular embodiment of the invention, the cationic direct dyes comprise at least one quaternized cationic chromophore.

[0035] As cationic direct dyes according to the invention, mention may be made of the following dyes: acridines; acridones; anthranthrones; anthrapyrimidines; anthraquinones; azines; (poly)azos, hydrazono or hydrazones, in particular arylhydrazones; azomethines; benzanthrones; benzimidazoles; benzimidazolones; benzindoles; benzoxazoles; benzopyrans; benzothiazoles; benzoquinones; bisazines; bis-isoindolines; carboxanilides; coumarins; cyanines such as azacarbocyanines, diazacarbocyanines, diazahemicyanines, hemicyanines, or tetraazacarbocyanines; diazines; diketopyrrolopyrroles; dioxazines; diphenylamines; diphenylmethanes; dithiazines; flavonoids such as flavanthrones and flavones; fluorindines; formazans; indamines; indanthrones; indigoids and pseudo-indigoids; indophenols; indoanilines; isoindolines; isoindolinones; isoviolanthrones; lactones; (poly)methines such as dimethines of stilbene or styryl type; naphthalimides; naphthanilides; naphtholactams; naphthoquinones; nitro, notably nitro(hetero)aromatics; oxadiazoles; oxazines; perilones; perinones; perylenes; phenazines; phenoxazine; phenothiazines; phthalocyanine; polyenes / carotenoids; porphyrins; pyranthrones; pyrazolanthrones; pyrazolones; pyrimidinoanthrones; pyronines; quinacridones; quinolines; quinophthalones; squaranes; tetrazoliums; thiazines, thioindigo; thiopyronines; triarylmethanes, or xanthenes.

[0036] For the cationic azo dyes, mention may be made particularly of those resulting from the cationic dyes described in the Kirk-Othmer Encyclopedia of Chemical Technology, “Dyes, Azo”, J. Wiley & Sons, updated on 19 April 2010.

[0037] Among the azo dyes that may be used according to the invention, mention may be made of the cationic azo dyes described in patent applications WO 95 / 15144, WO 95 / 01772 and EP714954.

[0038] Among the azo dyes described in the Colour Index International 3rd edition, mention may be made notably of the following compounds:

[0039] -Basic Red 22

[0040] -Basic Red 76

[0041] -Basic Yellow 57

[0042] -Basic Brown 16

[0043] -Basic Brown 17.

[0044] Among the cationic quinone dyes, those mentioned in the abovementioned Colour Index International are suitable for use and, among these, mention may be made, inter alia, of the following dyes:

[0045] -Basic Blue 22

[0046] -Basic Blue 99.

[0047] Among the azine dyes that are suitable for use, mention may be made of those listed in the Colour Index International, for example the following dyes:

[0048] -Basic Blue 17.

[0049] -Basic Red 2.

[0050] Among the cationic triarylmethane dyes that may be used according to the invention, mention may be made, in addition to those listed in the Colour Index, of the following dyes:

[0051] -Basic Green 1

[0052] -Basic Violet 3

[0053] -Basic Violet 14

[0054] -Basic Blue 7

[0055] -Basic Blue 26.

[0056] Mention may also be made of the cationic dyes described in the documents US 5888252, EP 1133975, WO 03 / 029359, EP 860636, WO 95 / 01772, WO 95 / 15144, EP 714954. Mention may also be made of those listed in the encyclopaedia “The Chemistry of Synthetic Dyes” by K. Venkataraman, 1952, Academic Press, vol. 1 to 7, in the “Kirk-Othmer Encyclopedia of Chemical Technology”, in the chapter “Dyes and Dye Intermediates”, 1993, Wiley and Sons, and in various chapters of “Ullmann’s Encyclopedia of Industrial Chemistry”, 7th edition, Wiley and Sons.

[0057] Preferably, the cationic direct dyes are chosen from those resulting from dyes of azo and hydrazono type.

[0058] According to a particular embodiment, the direct dyes are cationic azo dyes, described in EP 850 636, FR 2 788 433, EP 920 856, WO 99 / 48465, FR 2 757 385, EP 850 637, EP 918 053, WO 97 / 44004, FR 2 570 946, FR 2 285 851, DE 2 538 363, FR 2 189 006, FR 1 560 664, FR 1 540 423, FR 1 567 219, FR 1 516 943, FR 1 221 122, DE 4 220 388, DE 4 137 005, WO 01 / 66646, US 5 708 151, WO 95 / 01772, WO 515 144, GB 1 195 386, US 3 524 842, US 5 879 413, EP 1 062 940, EP 1 133 976, GB 738 585, DE 2 527 638, FR 2 275 462, GB 1974-27645, Acta Histochem. (1978), 61(1), 48-52; Tsitologiya (1968), 10(3), 403-5; Zh. Obshch. Khim. (1970), 40(1), 195-202; Ann. Chim. (Rome) (1975), 65(5-6), 305-14; Journal of the Chinese Chemical Society (Taipei) (1998), 45(1), 209-211; Rev. Roum. Chim. (1988), 33(4), 377-83; Text. Res. J. (1984), 54(2), 105-7; Chim. Ind. (Milan) (1974), 56(9), 600-3; Khim. Tekhnol. (1979), 22(5), 548-53; Ger. Monatsh. Chem. (1975), 106(3), 643-8; MRL Bull. Res. Dev. (1992), 6(2), 21-7; Lihua Jianyan, Huaxue Fence (1993), 29(4), 233-4; Dyes Pigm. (1992), 19(1), 69-79; Dyes Pigm. (1989), 11(3), 163-72.

[0059] Preferably, the cationic direct dye(s) comprise a quaternary ammonium group; more preferentially, the cationic charge is endocyclic.

[0060] These cationic radicals are, for example, a cationic radical:

[0061] - bearing a (di / tri)(C1-C8)alkylammonium exocyclic charge, or

[0062] - bearing an endocyclic charge, such as comprising a cationic heteroaryl group chosen from: acridinium, benzimidazolium, benzobistriazolium, benzopyrazolium, benzopyridazinium, benzoquinolium, benzothiazolium, benzotriazolium, benzoxazolium, bipyridinium, bistetrazolium, dihydrothiazolium, imidazopyridinium, imidazolium, indolium, isoquinolium, naphthoimidazolium, naphthoxazolium, naphthopyrazolium, oxadiazolium, oxazolium, oxazolopyridinium, oxonium, phenazinium, phenooxazolium, pyrazinium, pyrazolium, pyrazoyltriazolium, pyridinium, pyridinoimidazolium, pyrrolium, pyrylium, quinolium, tetrazolium, thiadiazolium, thiazolium, thiazolopyridinium, thiazoylimidazolium, thiopyrylium, triazolium or xanthylium.

[0063] Mention may be made of the hydrazono cationic dyes of formulae (C-II) and (C-III), the azo dyes of formulae (C-IV) and (C-V) below, and also the optical and geometric isomers thereof and tautomers thereof, the organic or mineral acid or base salts thereof, and also the solvates thereof such as hydrates:

[0064] Het+-C(Ra)=N-N(Rb)-Ar, Q-(C-II)

[0065] Het+-N(Ra)-N=C(Rb)-Ar, Q-(C-III)

[0066] Het+-N=N-Ar, Q-(C-IV)

[0067] Ar+-N=N-Ar’’, Q-(C-V),

[0068] in which formulae (C-II) to (C-V):

[0069] * Het+represents a cationic heteroaryl radical, preferentially bearing an endocyclic cationic charge, such as imidazolium, indolium or pyridinium, which is optionally substituted, preferentially with at least one (C1-C8)alkyl group such as methyl;

[0070] * Ar+represents an aryl radical, such as phenyl or naphthyl, bearing an exocyclic cationic charge, preferentially ammonium, particularly tri(C1-C8)alkylammonium, such as trimethylammonium;

[0071] * Ar represents an aryl group, notably phenyl, which is optionally substituted, preferentially with one or more electron-donating groups such as i) optionally substituted (C1-C8)alkyl, ii) optionally substituted (C1-C8)alkoxy, iii) (di)(C1-C8)(alkyl)amino optionally substituted on the alkyl group(s) with a hydroxyl group, iv) aryl(C1-C8)alkylamino, v) optionally substituted N-(C1-C8)alkyl-N-aryl(C1-C8)alkylamino or alternatively Ar represents a julolidine group;

[0072] * Ar’’ represents an optionally substituted (hetero)aryl group, such as phenyl or pyrazolyl, which are optionally substituted, preferentially with one or more (C1-C8)alkyl, hydroxyl, (di)(C1-C8)(alkyl)amino, (C1-C8)alkoxy or phenyl groups;

[0073] * Ra and Rb, which may be identical or different, represent a hydrogen atom or a (C1-C8)alkyl group, which is optionally substituted, preferentially with a hydroxyl group;

[0074] * or else the substituent Ra with a substituent of Het+and / or Rb with a substituent of Ar form, together with the atoms that bear them, a (hetero)cycloalkyl; in particular, Ra and Rb represent a hydrogen atom or a (C1-C4)alkyl group optionally substituted with a hydroxyl group;

[0075] * Q-represents an organic or mineral anionic counterion, such as a halide or an alkyl sulfate.

[0076] In particular, mention may be made of the azo and hydrazono direct dyes bearing endocyclic cationic charges, of formulae (C-II) to (C-V) as defined previously; more particularly the cationic direct dyes of formulae (C-II) to (C-V) bearing endocyclic cationic charges described in patent applications WO 95 / 15144, WO 95 / 01772 and EP-714954.

[0077] Preferentially, mention may be made of the following direct dyes: (C-II-1), (C-IV-1),

[0078] in which formulae (C-II-1) and (C-IV-1):

[0079] - R1represents a (C1-C4)alkyl group such as methyl;

[0080] - R2and R3, which may be identical or different, represent a hydrogen atom or a (C1-C4)alkyl group, such as methyl; and

[0081] - R4represents a hydrogen atom or an electron-donating group such as optionally substituted (C1-C8)alkyl, optionally substituted (C1-C8)alkoxy, or (di)(C1-C8)(alkyl)amino optionally substituted on the alkyl group(s) with a hydroxyl group; in particular, R4is a hydrogen atom;

[0082] - Z represents a CH group or a nitrogen atom, preferentially CH;

[0083] - Q-is an anionic counterion as defined previously, in particular a halide, such as chloride, or an alkyl sulfate, such as methyl sulfate or mesityl.

[0084] In particular, the dyes of formulae (C-II-1) and (C-IV-1) are chosen from Basic Red 51, Basic Yellow 87 and Basic Orange 31 or derivatives thereof: Basic Red 51 Basic Orange 31 Basic Yellow 87,

[0085] with Q’ being an anionic counterion as defined above, particularly a halide, such as chloride, or an alkyl sulfate, such as methyl sulfate or mesityl.

[0086] According to a particular embodiment of the invention, the direct dyes are fluorescent, i.e. they contain at least one fluorescent chromophore as defined above.

[0087] Fluorescent dyes that may be mentioned include the radicals resulting from the following dyes: acridines, acridones, benzanthrones, benzimidazoles, benzimidazolones, benzindoles, benzoxazoles, benzopyrans, benzothiazoles, coumarins, difluoro{2-[(2H-pyrrol-2-ylidene-kN)methyl]-1H-pyrrolato-kN}borons (BODIPY®), diketopyrrolopyrroles, fluorindines, (poly)methines (notably cyanines and styryls / hemicyanines), naphthalimides, naphthanilides, naphthylamines (such as dansyls), oxadiazoles, oxazines, perilones, perinones, perylenes, polyenes / carotenoids, squaranes, stilbenes and xanthenes.

[0088] Mention may also be made of the fluorescent dyes described in the documents EP 1133975, WO 03 / 029359, EP 860636, WO 95 / 01772, WO 95 / 15144, EP 714954 and those listed in the encyclopaedia “The Chemistry of Synthetic Dyes” by K. Venkataraman, 1952, Academic Press, vol. 1 to 7, in the “Kirk-Othmer Encyclopedia of Chemical Technology”, in the chapter “Dyes and Dye Intermediates”, 1993, Wiley and Sons, and in various chapters of “Ullmann’s Encyclopedia of Industrial Chemistry”, 7th edition, Wiley and Sons, and in the handbook — “A Guide to Fluorescent Probes and Labeling Technologies”, 10th Ed., Molecular Probes / Invitrogen – Oregon 2005, circulated on the Internet or in the preceding printed editions.

[0089] According to one variant of the invention, the cationic dye(s) are fluorescent and comprise at least one quaternary ammonium radical such as those of formula (C-VI) below, and also the optical and geometric isomers thereof and tautomers thereof, the organic or mineral acid or base salts thereof, and also the solvates thereof such as hydrates:

[0090] W+–[C(Rc)=C(Rd)]m’–Ar, Q-(C-VI),

[0091] in which formula (C-VI):

[0092] * W+represents a cationic heterocyclic or heteroaryl group, particularly comprising a quaternary ammonium optionally substituted with one or more (C1-C8)alkyl groups, optionally substituted notably with one or more hydroxyl groups;

[0093] * Ar representing an aryl group such as phenyl or naphthyl, optionally substituted preferentially with i) one or more halogen atoms such as chlorine or fluorine; ii) one or more (C1-C8)alkyl groups, preferably a C1-C4alkyl group such as methyl; iii) one or more hydroxyl groups; iv) one or more (C1-C8)alkoxy groups such as methoxy; v) one or more hydroxy(C1-C8)alkyl groups such as hydroxyethyl, vi) one or more amino or (di)(C1-C8)alkylamino groups, preferably with the C1-C4alkyl part optionally substituted with one or more hydroxyl groups, such as (di)hydroxyethylamino, vii) one or more acylamino groups; viii) one or more heterocycloalkyl groups such as piperazinyl, piperidyl or 5- or 6-membered heteroaryl such as pyrrolidinyl, pyridyl and imidazolinyl;

[0094] * m’ represents an integer between 1 and 4 inclusive, and in particular m is 1 or 2; more preferentially 1;

[0095] * Rcand Rd, which may be identical or different, represent a hydrogen atom or an optionally substituted (C1-C8)alkyl group, preferentially a C1-C4alkyl group, or alternatively Rccontiguous with W+and / or Rdcontiguous with Ar form, with the atoms that bear them, a (hetero)cycloalkyl; in particular, Rcis contiguous with W+and they form a (hetero)cycloalkyl such as cyclohexyl;

[0096] * Q-is an organic or mineral anionic counterion as defined previously.

[0097] Among the cationic direct dyes, mention may also be made of triarylmethane cationic dyes.

[0098] Preferably, the triarylmethane cationic direct dye(s) according to the invention are chosen from the cationic dyes of formulae (C-VII) and (C-VII’) below: (C-VII), (C-VII’),

[0099] and also the organic or mineral acid or base addition salts thereof, the optical and geometric isomers thereof and tautomers thereof, and the mesomeric forms thereof, and the solvates thereof such as hydrates:

[0100] in which formulae (C-VII) and (C-VII’):

[0101] * R1, R2, R3and R4, which may be identical or different, represent a hydrogen atom or group from among: (C1-C6)alkyl which is optionally substituted, preferably with a hydroxyl group; aryl such as phenyl, aryl(C1-C4)alkyl such as benzyl, heteroaryl, heteroaryl(C1-C4)alkyl, or else two groups R1and R2, and / or R3and R4, borne by the same nitrogen atom, form, together with the nitrogen atom which bears them, an optionally substituted heterocycloalkyl group such as morpholino, piperazino or piperidino; preferably, R1, R2, R3and R4, which may be identical or different, represent a hydrogen atom or a (C1-C4)alkyl group;

[0102] * R5, R6, R7, R8, R9, R10, R11, R12, R13, R14, R15and R16, which may be identical or different, represent a hydrogen or halogen atom or a group chosen from i) hydroxyl, ii) thiol, iii) amino, iv) (di)(C1-C4)(alkyl)amino, v) (di)arylamino such as (di)phenylamino, vi) nitro, vii) acylamino (-NR-C(O)R’) in which the radical R is a hydrogen atom, a C1-C4alkyl radical optionally bearing at least one hydroxyl group and the radical R’ is a C1-C2alkyl radical; viii) carbamoyl ((R)2N-C(O)-) in which the radicals R, which may be identical or different, represent a hydrogen atom or a C1-C4alkyl radical optionally bearing at least one hydroxyl group; ix) carboxylic acid or ester, (-O-C(O)R’) or

[0103] (-C(O)OR’), in which the radical R’ is a hydrogen atom or a C1-C4alkyl optionally bearing at least one hydroxyl group and the radical R’ is a C1-C2alkyl radical; x) alkyl optionally substituted notably with a hydroxyl group; xi) alkylsulfonylamino (R’SO2-NR-) in which the radical R represents a hydrogen atom or a C1-C4alkyl radical optionally bearing at least one hydroxyl group and the radical R’ represents a C1-C4alkyl radical or a phenyl radical; xii) aminosulfonyl ((R)2N-SO2-) in which the radicals R, which may be identical or different, represent a hydrogen atom or a C1-C4alkyl radical optionally bearing at least one hydroxyl group, xiii) (C1-C4)alkoxy, and xiv) (C1-C4)alkylthio;

[0104] * or else two radicals borne by two contiguous carbon atoms R5and R6and / or R7and R8and / or R9and R10and / or R11and R12and / or R13and R14and / or R15and R16form, together with the carbon atoms which bear them, an aryl or heteroaryl, preferably benzo, 6-membered fused ring, said ring possibly also being optionally substituted, preferably an unsubstituted benzo ring;

[0105] * Q-represents an anionic counterion for achieving electrical neutrality, preferably chosen from halides such as chloride or bromide, and phosphate.

[0106] When the cationic dye comprises one or more anionic substituents such as COOR or SO3R with R denoting a hydrogen or a cation, it is understood that there are then more cationic substituents than anionic substituents, such that the overall resulting charge of the triarylmethane structure is cationic.

[0107] According to a preferred embodiment, the triarylmethane dye(s) is / are chosen from those of formula (C-VII) or (C-VII’), in which, taken together or separately,

[0108] - R1, R2, R3and R4represent a hydrogen atom or a (C1-C4)alkyl group such as methyl or ethyl,

[0109] - R5, R6, R7, R8, R9, R10, R11, R12, R13, R14, R15and R16represent a hydrogen atom, a halogen atom, such as chlorine, or a (C1-C4)alkyl group such as methyl or ethyl, an amino group, a (di)(C1-C4)(alkyl)amino group and, preferably, at least one of the groups R9, R10, R11or R12represents a hydrogen atom, a halogen atom (Cl), or an amino group, or a (C1-C4)(alkyl)amino or (di)(C1-C4)(alkyl)amino group, preferably in the para position relative to the phenyl group.

[0110] Preferably, the direct dye(s) of triaylmethane structure are chosen from Basic Violet 1, Basic Violet 2, Basic Violet 3, Basic Violet 4, Basic Violet 14, Basic Blue 1, Basic Blue 7, Basic Blue 26, Basic Green 1, Basic Blue 77 (also known as HC Blue 15), and mixtures thereof.

[0111] Among the cationic direct dyes, mention may also be made of anthraquinone cationic dyes.

[0112] The anthraquinone cationic direct dye(s) that can be used in the dyeing composition (A) of the invention comprise a quaternary ammonium group.

[0113] These cationic radicals are, for example, a cationic radical:

[0114] - bearing a (C1-C8)alkylammonium exocyclic charge, or

[0115] - bearing an endocyclic charge, such as comprising a cationic heteroaryl group chosen from: acridinium, benzimidazolium, benzobistriazolium, benzopyrazolium, benzopyridazinium, benzoquinolium, benzothiazolium, benzotriazolium, benzoxazolium, bipyridinium, bistetrazolium, dihydrothiazolium, imidazopyridinium, imidazolium, indolium, isoquinolium, naphthoimidazolium, naphthoxazolium, naphthopyrazolium, oxadiazolium, oxazolium, oxazolopyridinium, oxonium, phenazinium, phenooxazolium, pyrazinium, pyrazolium, pyrazoyltriazolium, pyridinium, pyridinoimidazolium, pyrrolium, pyrylium, quinolium, tetrazolium, thiadiazolium, thiazolium, thiazolopyridinium, thiazoylimidazolium, thiopyrylium, triazolium or xanthylium.

[0116] Preferably, the cationic charge is exocyclic.

[0117] Among the anthraquinone cationic direct dyes, those of formula (C-VIII) having an exocyclic cationic charge are preferred: (C-VIII)

[0118] in which:

[0119] - R1, R2and R3, which may be identical or different, represent a hydrogen atom or an optionally substituted (C1-C8)alkyl group;

[0120] - R4represents a hydrogen atom or an optionally substituted (C1-C8)alkyl group;

[0121] - R5represents a hydrogen atom, an optionally substituted (C1-C8)alkyl group, an optionally substituted (C1-C8)alkylene group, a halogen, a hydroxyl group or a (C1-C8)alkoxy group;

[0122] - n represents a number between 1 and 8;

[0123] - Q-represents an organic or mineral anionic counterion, such as a halide or an alkyl sulfate.

[0124] Preferably, in formula (C-VIII):

[0125] - R1, R2and R3, which may be identical or different, represent an optionally substituted (C1-C6)alkyl group;

[0126] R4represents a hydrogen atom or an optionally substituted (C1-C6)alkyl group;

[0127] - R5represents a hydrogen atom or an optionally substituted (C1-C8)alkyl group;

[0128] - n represents a number between 1 and 6;

[0129] - Q-represents a halide or an alkyl sulfate.

[0130] More preferentially, in formula (C-VIII):

[0131] - R1, R2and R3, which may be identical or different, represent an optionally substituted (C1-C3)alkyl group;

[0132] - R4represents a hydrogen atom or a methyl, preferably a methyl;

[0133] - R5represents a hydrogen atom or a methyl, preferably a hydrogen atom;

[0134] - n represents a number between 2 and 4;

[0135] - Q-represents a halide or an alkyl sulfate, preferably a halide.

[0136] Among the dyes of formula (C-VIII), use may in particular be made of the dyes of formula (C-VIII’) or of formula (C-VIII’’) below: (C-VIII’) (C-VIII’’)

[0137] with Q-being an anionic counterion, particularly a halide, such as bromide or chloride, or an alkyl sulfate, such as methyl sulfate or mesityl. Preferably, Q-is a halide, better still a bromide.

[0138] The term “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 C1-C6alkylsulfonates: Alk-S(O)2O-such as methanesulfonate or mesylate and ethanesulfonate; iv) arylsulfonates: Ar-S(O)2O-such as benzenesulfonate and toluenesulfonate or tosylate; v) citrate; vi) succinate; vii) tartrate; viii) lactate; ix) alkyl sulfates: Alk-O-S(O)O-such as methyl sulfate and ethyl sulfate; x) aryl sulfates: Ar-O-S(O)O-such as benzene sulfate and toluene sulfate; xi) alkoxy sulfates: Alk-O-S(O)2O-such as methoxy sulfate and ethoxy sulfate; xii) aryloxy sulfates: Ar-O-S(O)2O-, xiii) phosphates O=P(OH)2-O-, O=P(O-)2-OH, O=P(O-)3, HO-[P(O)(O-)]w-P(O)(O-)2with w being an integer; xiv) acetate; xv) triflate; xvi) borates, such as tetrafluoroborate, and xvii) disulfate (O=)2S(O-)2or SO42-and monosulfate HSO4-.

[0139] One particularly preferred dye of formula (C-VIII’) is HC Blue 17.

[0140] One particularly preferred dye of formula (C-VIII’’) is HC Blue 16 (1-methylamino-4-(3’-dimethylpropylammoniumpropylamino)anthraquinone bromide).

[0141] Preferentially, the anthraquinone cationic direct dye(s) are chosen from the dyes of formulae (C-VIII’) and (C-VIII’’), and more preferentially from the dyes of formula (C-VIII’’), better still from HC Blue 16.

[0142] The dyeing composition (A) according to the invention may comprise one or more anionic direct dyes.

[0143] The anionic direct dyes of the invention are dyes commonly referred to as “acid” direct dyes owing to their affinity for alkaline substances. “Anionic direct dye” is understood to mean any direct dye including in its structure at least one CO2R or SO3R substituent with R denoting a hydrogen atom or a cation originating from a metal or an amine, or an ammonium ion. The anionic dyes may be chosen from direct nitro acid dyes, azo acid dyes, azine acid dyes, triarylmethane acid dyes, indoamine acid dyes, anthraquinone acid dyes, indigoid acid dyes and natural acid dyes.

[0144] According to the invention, the anionic direct dye(s) may be chosen, alone or as a mixture, from the anionic direct dyes of formulae (A-II), (A-II’), (A-III), (A-III’), (A-IV), (A-IV’), (A-V), (A-V’), (A-VI), (A-VII), (A-VIII) and (A-IX) below:

[0145] a) the diaryl anionic azo dyes of formula (A-II) or (A-II’): (A-II) (A-II’),

[0146] in which formulae (A-II) and (A-II’):

[0147] * R7, R8, R9, R10, R’7, R’8, R’9and R’10, which may be identical or different, represent a hydrogen atom or a group chosen from:

[0148] - alkyl;

[0149] - alkoxy, alkylthio;

[0150] - hydroxy, mercapto;

[0151] - nitro, nitroso;

[0152] - R°-C(X)-X’-, R°-X’-C(X)-, R°-X’-C(X)-X’’- with R° representing a hydrogen atom or an alkyl or aryl group; X, X’ and X’’, which may be identical or different, representing an oxygen or sulfur atom, or NR with R representing a hydrogen atom or an alkyl group;

[0153] - (O)2S(O-)-, M+with M+representing a hydrogen atom or a cationic counterion;

[0154] - (O)CO--, M+with M+as defined previously;

[0155] - R’’-S(O)2-, with R’’ representing a hydrogen atom or an alkyl group, an aryl, (di)(alkyl)amino or aryl(alkyl)amino group; preferentially a phenylamino or phenyl group;

[0156] - R’’’-S(O)2-X’- with R’’’ representing an optionally substituted alkyl or aryl group, X’ as defined previously;

[0157] - (di)(alkyl)amino;

[0158] - aryl(alkyl)amino optionally substituted with one or more groups chosen from i) nitro; ii) nitroso; iii) (O)2S(O-)-, M+and iv) alkoxy with M+as defined above;

[0159] - optionally substituted heteroaryl; preferentially a benzothiazolyl group;

[0160] - cycloalkyl; notably cyclohexyl;

[0161] - Ar-N=N- with Ar representing an optionally substituted aryl group; preferentially a phenyl optionally substituted with one or more alkyl, (O)2S(O-)-, M+or phenylamino groups;

[0162] - or alternatively two contiguous groups R7with R8or R8with R9or R9with R10together form a fused benzo group A’; and R’7with R’8or R’8with R’9or R’9with R’10together form a fused benzo group B’; with A’ and B’ optionally substituted with one or more groups chosen from i) nitro; ii) nitroso; iii) (O)2S(O-)-, M+; iv) hydroxyl; v) mercapto; vi) (di)(alkyl)amino; vii) R°-C(X)-X’-; viii) R°-X’-C(X)-; ix) R°-X’-C(X)-X’’-; x) Ar-N=N- and xi) optionally substituted aryl(alkyl)amino; with M+, R°, X, X’, X’’ and Ar as defined previously;

[0163] * W represents a sigma bond σ, an oxygen or sulfur atom, or a divalent radical i) –NR- with R as defined previously, or ii) methylene -C(Ra)(Rb)- with Ra and Rb, which may be identical or different, representing a hydrogen atom or an aryl group, or alternatively Ra and Rb form, together with the carbon atom that bears them, a spiro cycloalkyl; preferentially, W represents a sulfur atom or Ra and Rb together form a cyclohexyl;

[0164] it being understood that formulae (A-II) and (A-II’) comprise at least one sulfonate radical (O)2S(O-)-, M+or one carboxylate radical (O)CO--, M+on one of the rings A, A’, B, B’ or C; preferentially sodium sulfonate.

[0165] As examples of dyes of formula (A-II), mention may be made of: Acid Red 1, Acid Red 4, Acid Red 13, Acid Red 14, Acid Red 18, Acid Red 27, Acid Red 28, Acid Red 32, Acid Red 33, Acid Red 35, Acid Red 37, Acid Red 40, Acid Red 41, Acid Red 42, Acid Red 44, Pigment Red 57, Acid Red 68, Acid Red 73, Acid Red 135, Acid Red 138, Acid Red 184, Food Red 1, Food Red 13, Acid Orange 6, Acid Orange 7, Acid Orange 10, Acid Orange 19, Acid Orange 20, Acid Orange 24, Acid Yellow 6, Acid Yellow 9, Acid Yellow 36, Acid Yellow 199, Food Yellow 3; Acid Violet 7, Acid Violet 14, Acid Blue 113, Acid Blue 117, Acid Black 1, Acid Brown 4, Acid Brown 20, Acid Black 26, Acid Black 52, Food Black 1, Food Black 2; Food Yellow 3 or Sunset Yellow;

[0166] and, as examples of dyes of formula (A-II’), mention may be made of: Acid Red 111, Acid Red 134, Acid Yellow 38;

[0167] b) the pyrazolone anionic azo dyes of formulae (A-III) and (A-III’): (A-III) (A-III’),

[0168] in which formulae (A-III) and (A-III’):

[0169] * R11, R12and R13, which may be identical or different, represent a hydrogen or halogen atom, an alkyl group or -(O)2S(O-), M+with M+as defined previously;

[0170] * R14represents a hydrogen atom, an alkyl group or a group -C(O)O-, M+with M+as defined previously;

[0171] * R15represents a hydrogen atom;

[0172] * R16represents an oxo group, in which case R’16is absent, or alternatively R15with R16together form a double bond;

[0173] * R17and R18, which may be identical or different, represent a hydrogen atom, or a group chosen from:

[0174] - (O)2S(O-)-, M+with M+as defined previously;

[0175] - Ar-O-S(O)2- with Ar representing an optionally substituted aryl group; preferentially a phenyl optionally substituted with one or more alkyl groups;

[0176] * R19and R20together form either a double bond, or a benzo group D’, which is optionally substituted;

[0177] * R’16, R’19and R’20, which may be identical or different, represent a hydrogen atom or an alkyl or hydroxyl group;

[0178] * R21represents a hydrogen atom or an alkyl or alkoxy group;

[0179] * Ra and Rb, which may be identical or different, are as defined previously; preferentially, Ra represents a hydrogen atom and Rb represents an aryl group;

[0180] * Y represents either a hydroxyl group or an oxo group;

[0181] * represents a single bond when Y is an oxo group; and represents a double bond when Y represents a hydroxyl group;

[0182] it being understood that formulae (A-III) and (A-III’) comprise at least one sulfonate radical (O)2S(O-)-, M+or one carboxylate radical -C(O)O-, M+on one of the rings D or E; preferentially sodium sulfonate.

[0183] As examples of dyes of formula (A-III), mention may be made of: Acid Red 195, Acid Yellow 23, Acid Yellow 27, Acid Yellow 76, and as examples of dyes of formula (A-III’), mention may be made of: Acid Yellow 17;

[0184] c) the anthraquinone dyes of formulae (A-IV) and (A-IV’): (A-IV), (A-IV’)

[0185] in which formulae (A-IV) and (A-IV’):

[0186] * R22, R23, R24, R25, R26and R27, which may be identical or different, represent a hydrogen or halogen atom, or a group chosen from:

[0187] - alkyl;

[0188] - hydroxyl, mercapto;

[0189] - alkoxy, alkylthio;

[0190] - optionally substituted aryloxy or arylthio, preferentially substituted with one or more groups chosen from alkyl and (O)2S(O-)-, M+with M+as defined previously;

[0191] - aryl(alkyl)amino optionally substituted with one or more groups chosen from alkyl and (O)2S(O-)-, M+with M+as defined previously;

[0192] - (di)(alkyl)amino;

[0193] - (di)(hydroxyalkyl)amino;

[0194] - (O)2S(O-)-, M+with M+as defined previously;

[0195] * Z’ represents a hydrogen atom or a group NR28R29with R28and R29, which may be identical or different, representing a hydrogen atom or a group chosen from:

[0196] - alkyl;

[0197] - polyhydroxyalkyl such as hydroxyethyl;

[0198] - aryl optionally substituted with one or more groups, particularly i) alkyl such as methyl, n-dodecyl, n-butyl; ii) (O)2S(O-)-, M+with M+as defined previously; iii) R°-C(X)-X’-, R°-X’-C(X)-, R°-X’-C(X)-X’’- with R°, X, X’ and X’’ as defined previously, preferentially R° represents an alkyl group;

[0199] - cycloalkyl, notably cyclohexyl;

[0200] * Z represents a group chosen from hydroxyl and NR’28R’29with R’28and R’29, which may be identical or different, representing the same atoms or groups as R28and R29as defined previously;

[0201] it being understood that formulae (A-IV) and (A-IV’) comprise at least one sulfonate radical (O)2S(O-)-, M+or one carboxylate radical -C(O)O-, M+; preferentially sodium sulfonate.

[0202] As examples of dyes of formula (A-IV), mention may be made of: Acid Blue 25, Acid Blue 43, Acid Blue 62, Acid Blue 78, Acid Blue 129, Acid Blue 138, Acid Blue 140, Acid Blue 251, Acid Green 25, Acid Green 41, Acid Violet 42, Acid Violet 43, Mordant Red 3; EXT Violet No. 2;

[0203] and, as examples of dyes of formula (A-IV’), mention may be made of: Acid Black 48;

[0204] d) the nitro dyes of formulae (A-V) and (A-V’): (A-V) (A-V’)

[0205] in which formulae (A-V) and (A-V’):

[0206] * R30, R31and R32, which may be identical or different, represent a hydrogen or halogen atom, or a group chosen from:

[0207] - alkyl;

[0208] - alkoxy optionally substituted with one or more hydroxyl groups, alkylthio optionally substituted with one or more hydroxyl groups;

[0209] - hydroxyl, mercapto;

[0210] - nitro, nitroso;

[0211] - polyhaloalkyl;

[0212] - R°-C(X)-X’-, R°-X’-C(X)-, R°-X’-C(X)-X’’- with R°, X, X’ and X’’ as defined previously;

[0213] - (O)2S(O-)-, M+with M+as defined previously;

[0214] - (O)CO--, M+with M+as defined previously;

[0215] - (di)(alkyl)amino;

[0216] - (di)(hydroxyalkyl)amino;

[0217] - heterocycloalkyl such as piperidino, piperazino or morpholino;

[0218] in particular, R30, R31and R32represent a hydrogen atom;

[0219] * Rc and Rd, which may be identical or different, represent a hydrogen atom or an alkyl group;

[0220] * W is as defined previously; W particularly represents an –NH– group;

[0221] * ALK represents a linear or branched divalent C1-C6alkylene group; in particular, ALK represents a -CH2-CH2- group;

[0222] * n is 1 or 2;

[0223] * p represents an integer inclusively between 1 and 5;

[0224] * q represents an integer inclusively between 1 and 4;

[0225] * u is 0 or 1;

[0226] * when n is 1, J represents a nitro or nitroso group; particularly nitro;

[0227] * when n is 2, J represents an oxygen or sulfur atom, or a divalent radical –S(O)m– with m representing an integer 1 or 2; preferentially, J represents an –SO2– radical;

[0228] * M’ represents a hydrogen atom or a cationic counterion;

[0229] * , which may be present or absent, represents a benzo group

[0230] optionally substituted with one or more groups R30as defined previously;

[0231] it being understood that formulae (A-V) and (A-V’) comprise at least one sulfonate radical (O)2S(O-)-, M+or one carboxylate radical -C(O)O-, M+; preferentially sodium sulfonate.

[0232] As examples of dyes of formula (A-V), mention may be made of: Acid Brown 13 and Acid Orange 3; as examples of dyes of formula (A-V’), mention may be made of: Acid Yellow 1, the sodium salt of 2,4-dinitro-1-naphthol-7-sulfonic acid, 2-piperidino-5-nitrobenzenesulfonic acid, 2-(4’-N,N-(2’’-hydroxyethyl)amino-2’-nitro)anilineethanesulfonic acid, 4-β-hydroxyethylamino-3-nitrobenzenesulfonic acid; EXT D&C Yellow 7;

[0233] e) the triarylmethane dyes of formula (A-VI): (A-VI)

[0234] in which formula (A-VI):

[0235] * R33, R34, R35and R36, which may be identical or different, represent a hydrogen atom or a group chosen from alkyl, optionally substituted aryl and optionally substituted arylalkyl; particularly an alkyl and benzyl group optionally substituted with a group (O)mS(O-)-, M+with M+and m as defined previously;

[0236] * R37, R38, R39, R40, R41, R42, R43and R44, which may be identical or different, represent a hydrogen atom or a group chosen from:

[0237] - alkyl;

[0238] - alkoxy, alkylthio;

[0239] - (di)(alkyl)amino;

[0240] - hydroxy, mercapto;

[0241] - nitro, nitroso;

[0242] - R°-C(X)-X’-, R°-X’-C(X)-, R°-X’-C(X)-X’’- with R° representing a hydrogen atom or an alkyl or aryl group; X, X’ and X’’, which may be identical or different, representing an oxygen or sulfur atom, or NR with R representing a hydrogen atom or an alkyl group;

[0243] - (O)2S(O-)-, M+with M+representing a hydrogen atom or a cationic counterion;

[0244] - (O)CO--, M+with M+as defined previously;

[0245] - or alternatively two contiguous groups R41with R42or R42with R43or R43with R44together form a fused benzo group: I’; with I’ optionally substituted with one or more groups chosen from i) nitro; ii) nitroso; iii) (O)2S(O-)-, M+; iv) hydroxyl; v) mercapto; vi) (di)(alkyl)amino; vii) R°-C(X)-X’-; viii) R°-X’-C(X)- and ix) R°-X’-C(X)-X’’-; with M+, R°, X, X’ and X’’ as defined previously;

[0246] in particular, R37to R40represent a hydrogen atom, and R41to R44, which may be identical or different, represent a hydroxyl group or (O)2S(O-)-, M+; and when R43with R44together form a benzo group, it is preferentially substituted with an (O)2S(O-)- group;

[0247] it being understood that at least one of the rings G, H, I or I’ comprises at least one sulfonate radical (O)2S(O-)- or one carboxylate radical -C(O)O-; preferentially sulfonate.

[0248] As examples of dyes of formula (A-VI), mention may be made of: Acid Blue 1; Acid Blue 3; Acid Blue 7, Acid Blue 9; Acid Violet 49; Acid Green 3; Acid Green 5; Acid Green 50;

[0249] f) the xanthene-based dyes of formula (A-VII): (A-VII)

[0250] in which formula (A-VII):

[0251] * R45, R46, R47and R48, which may be identical or different, represent a hydrogen or halogen atom;

[0252] * R49, R50, R51and R52, which may be identical or different, represent a hydrogen or halogen atom, or a group chosen from:

[0253] - alkyl;

[0254] - alkoxy, alkylthio;

[0255] - hydroxy, mercapto;

[0256] - nitro, nitroso;

[0257] - (O)2S(O-)-, M+with M+representing a hydrogen atom or a cationic counterion;

[0258] - (O)CO--, M+with M+as defined previously;

[0259] particularly, R49, R50, R51and R52represent a hydrogen or halogen atom;

[0260] * G represents an oxygen or sulfur atom or an NR group with R representing a hydrogen atom or an alkyl group; in particular, G represents an oxygen atom;

[0261] * L represents an alkoxide O-, M+; a thioalkoxide S-, M+or a group NRf, with Rf representing a hydrogen atom or an alkyl group and M+as defined previously; M+is particularly sodium or potassium;

[0262] * L’ represents an oxygen or sulfur atom or an ammonium group: N+RfRg, with Rf and Rg, which may be identical or different, representing a hydrogen atom or an optionally substituted alkyl or aryl group; L’ particularly represents an oxygen atom or a phenylamino group optionally substituted with one or more alkyl or (O)mS(O-)-, M+groups with m and M+as defined previously;

[0263] * Q and Q’, which may be identical or different, represent an oxygen or sulfur atom; particularly, Q and Q’ represent an oxygen atom;

[0264] * M+is as defined previously.

[0265] As examples of dyes of formula (A-VII), mention may be made of: Acid Yellow 73; Acid Red 51; Acid Red 52; Acid Red 87; Acid Red 92; Acid Red 95; Acid Violet 9;

[0266] g) the indole-based dyes of formula (A-VIII): (A-VIII),

[0267] in which formula (A-VIII):

[0268] * R53, R54, R55, R56, R57, R58, R59and R60, which may be identical or different, represent a hydrogen atom or a group chosen from:

[0269] - alkyl;

[0270] - alkoxy, alkylthio;

[0271] - hydroxy, mercapto;

[0272] - nitro, nitroso;

[0273] - R°-C(X)-X’-, R°-X’-C(X)-, R°-X’-C(X)-X’’- with R° representing a hydrogen atom or an alkyl or aryl group; X, X’ and X’’, which may be identical or different, representing an oxygen or sulfur atom, or NR with R representing a hydrogen atom or an alkyl group;

[0274] - (O)2S(O-)-, M+with M+representing a hydrogen atom or a cationic counterion;

[0275] - (O)CO--, M+with M+as defined previously;

[0276] * G represents an oxygen or sulfur atom or an NR group with R representing a hydrogen atom or an alkyl group; in particular, G represents an oxygen atom;

[0277] * Ri and Rh, which may be identical or different, represent a hydrogen atom or an alkyl group;

[0278] it being understood that formula (A-VIII) comprises at least one sulfonate radical (O)2S(O-)-, M+or one carboxylate radical -C(O)O-, M+; preferentially sodium sulfonate.

[0279] As examples of dyes of formula (A-VIII), mention may be made of: Acid Blue 74.

[0280] h) the quinoline-based dyes of formula (A-IX): (A-IX),

[0281] in which formula (A-IX):

[0282] * R61represents a hydrogen or halogen atom or an alkyl group;

[0283] * R62, R63and R64, which may be identical or different, represent a hydrogen atom or a group (O)2S(O-)-, M+with M+representing a hydrogen atom or a cationic counterion;

[0284] * or alternatively R61with R62, or R61with R64, together form a benzo group optionally substituted with one or more groups (O)2S(O-)-, M+with M+representing a hydrogen atom or a cationic counterion;

[0285] it being understood that formula (A-IX) comprises at least one sulfonate radical (O)2S(O-)-, M+, preferentially sodium sulfonate.

[0286] As examples of dyes of formula (A-IX), mention may be made of: Acid Yellow 2, Acid Yellow 3 and Acid Yellow 5.

[0287] More particularly, the dyeing composition (A) comprises one or more anionic direct dyes chosen, alone or as a mixture, from the following anionic direct dyes:

[0288] (C.I. 45380)Acid Red 87 (A-VII)(C.I. 10316)Sodium salt of 2,4-dinitro-1-naphthol-7-sulfonic acid (A-V’)(C.I. 10383)Acid Orange 3 (A-V)(C.I. 13015)Acid Yellow 9 / Food Yellow 2 (A-II)(C.I. 14780) / Direct Red 45 / Food Red 13 (A-II)(C.I. 13711)Acid Black 52 (A-II)(C.I. 13065)Acid Yellow 36 (A-II)(C.I. 14700)Sodium salt of 1-hydroxy-2-(2’,4’-xylyl-5-sulfonatoazo)naphthalene-4-sulfonic acid / Food Red 1 (A-II)(C.I. 14720)Acid Red 14 / Food Red 3 / Mordant Blue 79 (A-II)(C.I. 14805)Sodium salt of 4-hydroxy-3-[(2-methoxy-5-nitrophenyl)diaza]-6-(phenylamino)naphthalene-2-sulfonic acid / Acid Brown 4 (A-II)(C.I. 15510)Acid Orange 7 / Pigment Orange 17 / Solvent Orange 49 (A-II)(C.I. 15985)Food Yellow 3 / Pigment Yellow 104 (A-II)(C.I. 16185)Acid Red 27 / Food Red 9 (A-II)(C.I. 16230)Acid Orange 10 / Food Orange 4 (A-II)(C.I. 16250)Acid Red 44 (A-II)(C.I. 17200)Acid Red 33 / Food Red 12 (A-II)(C.I. 15685)Acid Red 184 (A-II)(C.I. 19125)Acid Violet 3 (A-II)(C.I. 18055)Sodium salt of 1-hydroxy-2-(4’-acetamidophenylazo)-8-acetamidonaphthalene-3,6-disulfonic acid / Acid Violet 7 / Food Red 11 (A-II)(C.I. 18130)Acid Red 135 (A-II)(C.I. 19130)Acid Yellow 27 (A-III)(C.I. 19140)Acid Yellow 23 / Food Yellow 4 (A-III)(C.I. 20170)4’-(Sulfonato-2’’,4’’-dimethyl)bis(2,6-phenylazo)-1,3-dihydroxybenzene / Acid Orange 24 (A-II)(C.I. 20470)Sodium salt of 1-amino-2-(4’-nitrophenylazo)-7-phenylazo-8-hydroxynaphthalene-3,6-disulfonic acid / Acid Black 1 (A-II)(C.I. 23266)(4-((4-Methylphenyl)sulfonyloxy)phenylazo)-2,2’-dimethyl-4-((2-hydroxy-5,8-disulfonato)naphthylazo)biphenyl / Acid Red 111 (A-II’)(C.I. 27755)Food Black 2 (A-II)(C.I. 25440)1-(4’-Sulfonatophenylazo)-4-((2’’-hydroxy-3’’-acetylamino-6’’,8’’-disulfonato)naphthylazo)-6-sulfonatonaphthalene (tetrasodium salt) / Food Black 1 (A-II)(C.I. 42090)Acid Blue 9 (A-VI)(C.I. 60730)Acid Violet 43 (A-IV)(C.I. 61570)Acid Green 25 (A-IV)(C.I. 62045)Sodium salt of 1-amino-4-cyclohexylamino-9,10-anthraquinone-2-sulfonic acid / Acid Blue 62 (A-IV)(C.I. 62105)Acid Blue 78 (A-IV)(C.I. 14710)Sodium salt of 4-hydroxy-3-((2-methoxyphenyl)azo)-1-naphthalenesulfonic acid / Acid Red 4 (A-II)2-Piperidino-5-nitrobenzenesulfonic acid (V’)2-(4’-N,N-(2’’-Hydroxyethyl)amino-2’-nitro)anilineethanesulfonic acid (A-V’)4-β-hydroxyethylamino-3-nitrobenzenesulfonic acid (A-V’)(C.I. 42640)Acid Violet 49 (A-VI)(C.I. 42080)Acid Blue 7 (A-VI)(C.I. 58005)Sodium salt of 1,2-dihydroxy-3-sulfoanthraquinone / Mordant Red 3 (A-IV)(C.I. 62055)Sodium salt of 1-amino-9,10-dihydro-9,10-dioxo-4-(phenylamino)-2-anthracenesulfonic acid / Acid Blue 25 (A-IV)(C.I. 14710)Sodium salt of 4-hydroxy-3-((2-methoxyphenyl)azo)-1-naphthalenesulfonic acid / Acid Red 4 (A-II)

[0289] Most of these dyes are described in particular in the Colour Index published by The Society of Dyers and Colourists, P.O. Box 244, Perkin House, 82 Grattan Road, Bradford, Yorkshire, BD1 2JB, England.

[0290] The anionic dyes which are most particularly preferred are the dyes designated in the Colour Index under the code C.I. 58005 (monosodium salt of 1,2-dihydroxy-9,10-anthraquinone-3-sulfonic acid), C.I. 60730 (monosodium salt of 2-[(9,10-dihydro-4-hydroxy-9,10-dioxo-1-anthracenyl)amino]-5-methylbenzenesulfonic acid), C.I. 15510 (monosodium salt of 4-[(2-hydroxy-1-naphthalenyl)azo]benzenesulfonic acid), C.I. 15985 (disodium salt of 6-hydroxy-5-[(4-sulfophenyl)azo]-2-naphthalenesulfonic acid), C.I. 17200 (disodium salt of 5-amino-4-hydroxy-3-(phenylazo)-2,7-naphthalenedisulfonic acid), C.I. 20470 (disodium salt of 1-amino-2-(4’-nitrophenylazo)-7-phenylazo-8-hydroxy-3,6-naphthalenedisulfonic acid), C.I. 42090 (disodium salt of N-ethyl-N-[4-[[4-[ethyl[(3-sulfophenyl)methyl]amino]phenyl](2-sulfophenyl)methylene]-2,5-cyclohexadien-1-ylidene]-3-sulfobenzenemethanaminium hydroxide, internal salt), C.I. 61570 (disodium salt of 2,2’-[(9,10-dihydro-9,10-dioxo-1,4-anthracenediyl)diimino]bis[5-methyl]benzenesulfonic acid).

[0291] Use may also be made of compounds corresponding to the mesomeric or tautomeric forms of structures (A-II) to (A-IX).

[0292] Among the natural direct dyes that may be used according to the invention, mention may be made of hennotannic acid, juglone, alizarin, purpurin, carminic acid, kermesic acid, purpurogallin, protocatechaldehyde, indigo, isatin, curcumin, spinulosin, apigenidin and orcein. Extracts or decoctions containing these natural dyes and in particular henna-based poultices or extracts may also be used.

[0293] Preferably, the dyeing composition (A) used in the process of the invention comprises one or more cationic direct dye(s).

[0294] More preferably, the dyeing composition (A) used in the process of the invention comprises one or more cationic direct dye(s) chosen from azo cationic direct dyes, hydrazono cationic direct dyes, anthraquinone cationic direct dyes, triarylmethane cationic direct dyes, and mixtures thereof.

[0295] Preferably, the dyeing composition (A) used in the process of the invention comprises one or more anionic direct dyes, preferably chosen from acid azo direct dyes, acid azine direct dyes, acid triarylmethane direct dyes, acid indoamine direct dyes, acid anthraquinone direct dyes, acid indigoid direct dyes, acid natural direct dyes, and mixtures thereof.

[0296] Advantageously, the total content of the direct dye(s) in the dyeing composition (A) applied in step i) ranges from 0.001% to 10%, preferably from 0.005% to 5% by weight, more preferentially from 0.01% to 2% by weight, better still from 0.02% to 1% by weight, relative to the total weight of the dyeing composition (A).

[0297] The dyeing composition (A) according to the invention may comprise water.

[0298] Preferably, the dyeing composition (A) comprises water.

[0299] Preferably, the dyeing composition (A) applied in step i) comprises water in a content ranging from 60% to 99.999% by weight, preferably from 65% to 99.995% by weight, more preferably from 70% to 99.99% by weight, and more preferentially from 75% to 99.98% by weight, relative to the total weight of the dyeing composition (A).

[0300] More preferably, when it is applied in step i) with the dispensing device 10, the dyeing composition (A), preferably liquid, applied in step i) comprises water in a content ranging from 80% to 99.999% by weight, preferably from 85% to 99.995% by weight, more preferably from 90% to 99.99% by weight, more preferentially from 95% to 99.98% by weight relative to the total weight of the dyeing composition (A).

[0301] The dyeing composition (A) may also comprise one or more organic solvents chosen from aromatic alcohols and alkylene carbonates.

[0302] Preferably, the dyeing composition (A) does comprise one or more organic solvents chosen from aromatic alcohols and alkylene carbonates.

[0303] Preferably, the organic solvent(s) are chosen from benzyl alcohol, phenethyl alcohol, cinnamic alcohol, phenyl propyl alcohol, 1-phenoxy-2-propanol, phenyl diglycol, α-methylbenzyl alcohol, dimethyl benzyl carbinol, benzyloxyethanol, phenoxyethanol, phenoxyisopropanol, p-anisyl alcohol, ethylene carbonate and propylene carbonate.

[0304] Even more preferentially, the organic solvent(s) are chosen from benzyl alcohol, ethylene carbonate and propylene carbonate.

[0305] When it comprises them, the dyeing composition (A) applied in step i) comprises one or more organic solvents chosen from aromatic alcohols and alkylene carbonates in a content ranging from 0.1% to 20% by weight, preferably from 0.5% to 15% by weight, more preferentially from 1% to 13% by weight relative to the total weight of the composition (A).

[0306] The dyeing composition (A) used in the process of the invention may also contain various adjuvants that are conventionally used in compositions for dyeing the hair, such as surfactants, notably anionic, cationic, nonionic, amphoteric or zwitterionic surfactants; polymers, notably anionic, cationic, amphoteric, zwitterionic or nonionic polymers; mineral or organic thickeners; antioxidants; sequestrants, fragrances, buffers, dispersants, ceramides, preservatives and opacifiers.

[0307] Needless to say, those skilled in the art will take care to choose this or these optional additional compounds such that the advantageous properties intrinsically associated with the dyeing composition (A) are not, or are not substantially, adversely affected by the envisaged addition(s).

[0308] Since the composition is applied using a dispensing device, the process according to the invention makes it possible to dispense with various compounds conventionally contained in dyeing compositions, thus limiting the amount of compounds present in the rinsing waters.

[0309] Preferably, the dyeing composition (A) applied in step i) comprises less than 1% by weight of fatty substance, preferably less than 0.5% by weight relative to the total weight of the composition (A), and better still contains no fatty substance.

[0310] “Fatty substance” is understood to mean an organic compound that is insoluble in water at 25°C and at atmospheric pressure (1.013×105 Pa) (solubility of less than 5% by weight, and preferably less than 1% by weight, even more preferentially less than 0.1% by weight). They bear in their structure at least one hydrocarbon chain including at least 6 carbon atoms and / or a sequence of at least two siloxane groups. In addition, the fatty substances are generally soluble in organic solvents under the same temperature and pressure conditions, for instance chloroform, dichloromethane, carbon tetrachloride, ethanol, benzene, toluene, tetrahydrofuran (THF), liquid petroleum jelly or decamethylcyclopentasiloxane.

[0311] Preferably, the dyeing composition (A) applied in step i) comprises less than 1% by weight of thickener, preferably less than 0.5% by weight relative to the total weight of the composition (A), and better still contains no thickener.

[0312] For the purposes of the present invention, the term “thickener” is intended to mean an agent which, when introduced at 1% by weight in an aqueous solution or an aqueous-alcoholic solution containing 30% ethanol, and at pH 7, makes it possible to achieve a viscosity of at least 100 cps (centipoise), in particular of at least 200 cps, preferably of at least 500 cps, measured at 25°C and at a shear rate of 1 s-1. This viscosity may be measured using a cone / plate viscometer (Haake R600 rheometer or the like).

[0313] Preferably, the dyeing composition (A) applied in step i) comprises less than 1% by weight of thickening polymer, preferably less than 0.5% by weight relative to the total weight of the composition (A), and better still contains no thickening polymer.

[0314] Preferably, the dyeing composition (A) applied in step i) comprises less than 1% by weight of mineral thickener, preferably less than 0.5% by weight relative to the total weight of the composition (A), and better still contains no mineral thickener.

[0315] Preferably, the dyeing composition (A) applied in step i) comprises less than 1% by weight of surfactant, preferably less than 0.5% by weight relative to the total weight of the composition (A), and better still contains no surfactant.

[0316] Preferably, the dyeing composition (A) is in the form of an aqueous solution.

[0317] The dyeing composition (A) is preferably liquid.

[0318] A “liquid composition” is understood to mean a composition with a viscosity of less than 50 mPa.s measured at 25°C and at a shear rate of 1 s-1; this viscosity can be determined by means of a Thermo Haake RS600 rotational rheometer fitted with plate-plate geometry, Ø 35 mm with a 1 mm gap.

[0319] Preferably, the dyeing composition (A) preferably has a viscosity of less than or equal to 50 mPa.s, preferably less than or equal to 20 mPa.s, better still less than or equal to 10 mPa.s, measured at 25°C and at a shear rate of 1 s-1; this viscosity can be determined by means of a Thermo Haake RS600 rotational rheometer fitted with plate-plate geometry, Ø 35 mm with a 1 mm gap.

[0320] The pH of the dyeing composition (A) used in the process in accordance with the invention is generally between 2.5 and 10. It may be adjusted to the desired value by means of acidifying or basifying agents that are usually used in the dyeing of keratin fibres, or alternatively using conventional buffer systems.

[0321] Among the acidifying agents, examples that may be mentioned include mineral or organic acids, such as hydrochloric acid, orthophosphoric acid, sulfuric acid, carboxylic acids, such as acetic acid, tartaric acid, citric acid or lactic acid, and sulfonic acids.

[0322] Among the basifying agents, examples that may be mentioned include aqueous ammonia, alkali metal carbonates, alkanolamines, such as monoethanolamine, diethanolamine and triethanolamine and derivatives thereof, sodium hydroxide, potassium hydroxide, and the compounds of the following formula:

[0323] in which W is a propylene residue optionally substituted by a hydroxyl group or a C1-C4alkyl radical; Ra, Rb, Rc and Rd, which may be identical or different, represent a hydrogen atom or a C1-C4alkyl or C1-C4hydroxyalkyl radical.

[0324] In particular, when the dyeing composition (A) comprises anionic direct dyes, the pH of the dyeing composition (A) is less than 7, preferably ranges from 2 to 5, it being possible for the pH to be adjusted by means of a carboxylic acid.

[0325] When the dyeing composition (A) comprises cationic direct dyes, and preferably when it does not comprise any anionic direct dyes, the pH of the dyeing composition (A) ranges from 6 to 12, preferably from 7 to 11.Pretreatment composition (B)

[0326] Before step i) of applying the dyeing composition (A) to the keratin fibres, the process according to the invention may comprise a step of applying to the keratin fibres a pretreatment composition (B) comprising one or more reducing agents.

[0327] Preferably, the process according to the invention does comprise a step of applying to the keratin fibres a pretreatment composition (B) comprising one or more reducing agents before step i) of applying the dyeing composition (A).

[0328] Preferably, the reducing agent(s) are chosen from thiol-based reducing agents, non-thiol reducing agents and mixtures thereof.

[0329] For the purposes of the present invention, the terms “thiol” and “thiol-based” refer to any molecule bearing an -SH group or a group that is capable of generating a thiol by a simple chemical or photochemical reaction (for example hydrolysis). Thus, for the purposes of the present invention, compounds bearing protected thiol functions as defined for example in “Protective Groups in Organic Synthesis”, T.W Greene and P.G.M Wuts, second edition, Protection for the Thiol Group, are equated to compounds bearing -SH thiol functions. For the purposes of the present invention, the term “non-thiol reducing agent” refers to a reducing agent which does not include any thiol groups.

[0330] The thiol-based reducing agent(s) according to the invention may be chosen from organic compounds including one or more –SH groups, and optionally at least one other function chosen from carboxylic acid, amine, amide, ester and alcohol functions and mixtures thereof.

[0331] Preferably, the thiol-based reducing agent(s) are chosen from the reducing agents of formula (i-1) below, mineral and / or organic salts thereof and mixtures thereof: (i-1)

[0332] in which formula (i-1):

[0333] ▪ R1represents:

[0334] - a (C1-C8)alkyl and preferably (C1-C6)alkyl group, optionally substituted with one or more groups chosen from carboxyl C(O)OH, (di)(C1-C4)(alkyl)amino, hydroxyl -OH, thiol –SH or –C(O)–NH–CH2–C(O)OH and / or optionally interrupted with one or more heteroatoms or groups chosen from –O–, –S–, –N(R’’’)– and C(O) or combinations thereof such as –O–C(O)–, –C(O)–O–, –C(O)–O–R*, –N(R’’’)–C(O)–, or –C(O)–N(R’’’)–; with R’’’ representing a hydrogen atom or a (C1-C6)alkyl group; R* representing a (C1-C6)alkyl group optionally substituted with one or more hydroxyl -OH, thiol –SH or amino -NH2groups; or

[0335] - a (hetero)aryl group optionally substituted with one or more hydroxyl, thiol or carboxyl groups;

[0336] ▪ R’ and R’’, which may be identical or different, represent a (C1-C8)alkyl and preferably (C1-C6)alkyl group, substituted with one or more groups chosen from hydroxyl, thiol and carboxyl, or combinations thereof;

[0337] or else R’ and R’’ form, together with the sulfur atom which bears them, a 5- to 7-membered heterocyclic group, which is preferably saturated, which comprises from 1 to 3 heteroatoms, and which is optionally substituted with one or more (C1-C6)alkyl groups optionally substituted with one or more hydroxyl, thiol or carboxyl groups; more preferentially, the heterocyclic group is a dithiolane group optionally substituted with a (C1-C6)alkyl group optionally substituted with one or more carboxyl groups.

[0338] According to a preferred embodiment of the invention, the thiol-based reducing agent(s) of formula (i-1) are chosen from those in which R1represents a (C1-C8)alkyl and preferably (C1-C6)alkyl group,

[0339] - substituted with one or more groups chosen from carboxyl C(O)OH, amino, hydroxyl -OH and thiol –SH; and / or

[0340] - optionally interrupted with one or more heteroatoms or groups chosen from –O–, –N(R’’’)–, C(O) or combinations thereof such as –O–C(O)–, –C(O)–O–, –N(R’’’)–C(O)–, or –C(O)–N(R’’’)–, with R’’’ representing a hydrogen atom or a (C1-C6)alkyl group.

[0341] According to a more preferred embodiment of the invention, the thiol-based reducing agent(s) of formula (i-1) are chosen from those in which R1represents a (C1-C8)alkyl and preferably (C1-C6)alkyl group, which is not interrupted and substituted with one or more groups chosen from carboxyl C(O)OH, amino, hydroxyl -OH, and thiol –SH.

[0342] According to another embodiment of the invention, the thiol-based reducing agent(s) of formula (i-1) are chosen from those in which R1represents:

[0343] - a phenyl group optionally substituted with one or more groups chosen from carboxyl C(O)OH, amino, hydroxyl -OH, and thiol –SH; or

[0344] - a 5- to 10-membered, preferably 9- or 10-membered bicyclic, heteroaryl group, comprising from 1 to 4 heteroatoms chosen from O, S or N, preferably N, optionally substituted with one or more hydroxyl or thiol groups.

[0345] The thiol-based reducing agent(s) according to the invention may notably be used in the form of mineral and / or organic salts, in particular alkali metal salts such as sodium and potassium salts, alkaline-earth metal salts, for example magnesium, calcium and strontium salts, which may or may not be hydrated, ammonium salts, hydrochloric acid salts, amine salts and amino alcohol salts, for example ethanolamine salts. Ammonium thioglycolate, cysteine hydrochloride or ethanolamine thioglycolate may thus be used as thiol-based reducing agent.

[0346] Preferably, the thiol-based reducing agent(s) are chosen from thioglycolic acid, thiolactic acid, cysteine, cysteamine, N-acetylcysteamine, N-proprionylcysteamine, cysteine, homocysteine, glutathione, thioglycerol, thiomalic acid, 3-mercaptopropionic acid, pantetheine, dimercaptosuccinic acid, thiosulfuric acid derivatives, 2-mercaptoethanol, dithiothreitol, thiosalicylic acid, thiodiglycolic acid, N-acetylcysteine, esters and amides of thioglycolic or thiolactic acids, notably glycerol monothioglycolate, mineral and / or organic salts thereof, and mixtures thereof.

[0347] More preferentially, the thiol-based reducing agent(s) are chosen from the group consisting of thioglycolic acid, thiolactic acid, cysteine, cysteamine, N-acetylcysteamine, glycerol monothioglycolate, thiosulfuric acid derivatives, mineral and / or organic salts thereof, and mixtures thereof.

[0348] Even more preferentially, the thiol-based reducing agent(s) may be chosen from thioglycolic acid, thiolactic acid, cysteine, mineral and / or organic salts thereof, such as cysteine hydrochloride, and mixtures thereof, better still from thioglycolic acid, mineral and / or organic salts thereof, and mixtures thereof.

[0349] The non-thiol reducing agent(s) according to the invention may be chosen from sulfites, bisulfites, sulfinates, phosphines, reducing sugars, and mixtures thereof.

[0350] Among the non-thiol reducing agents chosen from sulfites and bisulfites, mention may notably be made of ammonium sulfites and bisulfites and metal sulfites and bisulfites, including alkali metal sulfites and bisulfites or alkaline-earth metal sulfites and bisulfites, such as sodium sulfites and bisulfites.

[0351] Among the non-thiol reducing agents chosen from sulfinates, mention may be made of sulfinic acid salts and benzenesulfinic acid salts such as the sodium salts thereof. The sulfinic acid derivatives described in FR-A-2814948 may also be used. Preferably, the non-thiol reducing agent chosen from sulfinates is the disodium salt of 2-hydroxy-2-sulfinatoacetic acid.

[0352] Among the non-thiol reducing agents chosen from phosphines, mention may be made of monophosphines and diphosphines, as described in FR-A-2870119.

[0353] According to a preferred embodiment, the phosphines are of formula (i-2) below, salts thereof, solvates thereof and mixtures thereof:

[0354] P(R41)(R42) (R43) (i-2)

[0355] in which formula (i-2):

[0356] R41, R42 and R43 independently denote a (C1-C6)alkyl group optionally substituted with one or more groups chosen from OH and COOH.

[0357] Preferably R41, R42 and R43 denote a group chosen from C1-C6 hydroxyalkyl, preferably C1-C4 hydroxyalkyl such as hydroxymethyl or hydroxypropyl such as 3-hydroxypropyl; C1-C6 carboxyalkyl, preferably C1-C4 carboxyalkyl such as 2-carboxyethyl.

[0358] According to a particularly preferred embodiment, the phosphines are chosen from the phosphines of formula (i-2) and R41, R42 and R43 are identical.

[0359] According to a particularly preferred embodiment, the phosphines are chosen from tris(hydroxymethyl)phosphine, tris(hydroxypropyl)phosphine, tris(2-carboxyethyl)phosphine and mixtures thereof.

[0360] According to a preferred embodiment of the invention, the phosphine(s) that may be used in the context of the invention are soluble in a cosmetically acceptable medium. Preferably, the phosphine(s) that may be used in the context of the invention are water-soluble.

[0361] In the context of the present invention, the term “water-soluble” refers to any phosphine whose solubility in water is greater than 0.01% by weight at 20°C.

[0362] Preferably, the phosphine is tris(2-carboxyethyl)phosphine or mineral and / or organic salts thereof.

[0363] Among the non-thiol reducing agents chosen from reducing sugars, mention may be made of glucose, fructose, maltose, ribose, galactose, lactose and xylose.

[0364] Advantageously, the reducing agent(s) are chosen from thiol-based reducing agents, sulfites, bisulfites, sulfinates, phosphines, reducing sugars, mineral and / or organic salts thereof, and mixtures thereof, preferably thiol-based reducing agents, phosphines, mineral and / or organic salts thereof, and mixtures thereof, more preferentially thiol-based reducing agents, mineral and / or organic salts thereof and mixtures thereof.

[0365] Preferably, the reducing agent(s) as defined previously is (are) present in a content ranging from 0.1% to 10% by weight, preferably from 0.5% to 8% by weight, preferentially from 1% to 7% by weight relative to the total weight of the pretreatment composition (B) according to the invention.

[0366] The pretreatment composition (B) may comprise water.

[0367] Preferably, the pretreatment composition (B) does comprise water, preferably in a content ranging from 90% to 99.5% by weight relative to the total weight of the pretreatment composition (B).

[0368] The pretreatment composition (B) preferably has a basic pH.

[0369] According to a preferred embodiment of the invention, the pH of the pretreatment composition (B) is greater than 7, preferably ranges from 8 to 12, more preferably from 9 to 11 and better still from 9.5 to 10.5.

[0370] The pH can be adjusted to the desired value by means of basifying agents usually used in the dyeing of keratin fibres, such as those described previously, or alternatively using standard buffer systems.Post-treatment composition (C)

[0371] After step iii) or after the optional rinsing step iv), the process according to the invention may comprise a step of applying a post-treatment composition (C) comprising one or more chemical oxidizing agents.

[0372] Preferably, the process according to the invention comprises a step of applying a post-treatment composition (C) comprising one or more chemical oxidizing agents.

[0373] “Chemical oxidizing agent” is understood to mean an oxidizing agent other than the oxygen from the air.

[0374] The chemical oxidizing agent(s) are chosen from hydrogen peroxide, urea peroxide, alkali metal bromates or ferricyanides, peroxygenated salts such as alkali metal or alkaline-earth metal persulfates, perborates and percarbonates, and peracids and precursors thereof.

[0375] More preferentially, the post-treatment composition (C) comprises hydrogen peroxide.

[0376] The total content of the chemical oxidizing agent(s) preferably ranges from 1% to 20% by weight, more preferentially from 1.5% to 15% by weight, better still from 2% to 10% by weight, relative to the total weight of the post-treatment composition (C).

[0377] The post-treatment composition (C) preferably comprises water. In particular, it comprises more than 10% by weight of water, preferably more than 30% by weight of water, and even more advantageously more than 50% by weight of water. Preferably, the post-treatment composition (C) comprises water in a content ranging from 10% to 95% by weight, preferably from 30% to 93% by weight, better still from 50% to 92% by weight, relative to the total weight of the post-treatment composition (C).

[0378] The pH of the post-treatment composition (C) is preferably less than 7, preferably between 1 and 5, preferentially between 1.5 and 4.5.

[0379] This pH can be adjusted to the desired value by using one or more acidifying agents.

[0380] Among the acidifying agents, mention may be made, by way of example, of mineral or organic acids, such as hydrochloric acid, orthophosphoric acid, sulfuric acid, carboxylic acids such as acetic acid, tartaric acid, citric acid or lactic acid, and sulfonic acids.Dyeing method

[0381] The process for dyeing keratin fibres according to the invention comprises:

[0382] i) applying to said keratin fibres a dyeing composition (A) as defined previously,

[0383] ii) recovering at least one portion of the dyeing composition (A) after applying to said keratin fibres,

[0384] iii) applying the dyeing composition (A) recovered in step ii) to said keratin fibres.

[0385] The dyeing composition (A) can then be applied in step i) to dry or wet keratin fibres.

[0386] Preferably, the dyeing composition (A), preferably liquid, is applied in step i) to the keratin fibres by means of the dispensing device 10 as described below.

[0387] As a variant, the dyeing composition (A) may be applied in step i) by hand to the keratin fibres, for example using a brush or a bottle, in a conventional manner. An aqueous solution, preferably water, is then applied to the keratin fibres.

[0388] At least one portion of the dyeing composition (A) is recovered in step ii), preferably in a tank, after application to the keratin fibres.

[0389] The portion of the dyeing composition (A) recovered in step ii) is then applied again to the keratin fibres in step iii).

[0390] In other words, the dyeing composition (A) recovered in step ii) is applied in step iii) to the same keratin fibers as in step i).

[0391] Thus, direct dye(s) are reapplied several times to the same keratin fibers.

[0392] Preferably, no direct dye(s) are added to the dyeing composition (A) recovered in step ii) before applying it to the keratin fibers in step iii).

[0393] Preferably, the part of the dyeing composition (A) recovered in step ii) is reapplied to the keratin fibers in step iii) by means of the dispensing device 10.

[0394] Preferably, steps ii) and iii) are repeated at least once, preferably several times. More preferentially, steps ii) and iii) are carried out continuously, in particular by means of the dispensing device 10.

[0395] The dyeing composition (A), preferably in liquid form, is thus dispensed on the hair in a continuous flow.

[0396] According to the process of the invention, the dyeing composition (A) is recycled and redispensed on the keratin fibres. The keratin fibres are thus subjected to several passes of the dyeing composition (A), allowing a greater amount of direct dyes to be fixed to the keratin fibres.

[0397] Preferably, steps i) to iii) of the dyeing process according to the invention are carried out for a period of time ranging from 1 to 45 minutes, preferably from 5 to 30 minutes.

[0398] At the end of the dyeing treatment, the keratin fibres are preferably rinsed with water during a rinsing step iv).

[0399] Preferably, the keratin fibres can then be washed with a shampoo and then rinsed with water, before being optionally wrung out, dried or left to dry.

[0400] According to a preferred embodiment, before step i) of applying the dyeing composition (A), the process according to the invention comprises a step of applying a pretreatment composition (B) as described above comprising one or more reducing agents.

[0401] The pretreatment composition (B) is preferably applied by hand to the keratin fibres using a brush, a spray or a pipette depending on the texture of the composition. It is preferably left on the keratin fibres for a time ranging from 1 to 15 minutes, preferably from 2 to 10 minutes, better still from 3 to 8 minutes.

[0402] The keratin fibres are then preferably rinsed with water before the application of the dyeing composition (A).

[0403] According to another preferred embodiment, the dyeing process according to the invention comprises, after step iii) or after the optional rinsing step iv), a step v) of applying a post-treatment composition (C) as described above, comprising one or more chemical oxidizing agents.

[0404] The post-treatment composition (C) can be applied to the keratin fibres with a brush. It is preferably left on the keratin fibres for a time ranging from 1 to 15 minutes, preferably from 2 to 10 minutes, better still from 3 to 8 minutes.

[0405] The keratin fibres can then be rinsed with water during a rinsing step, and then optionally dried or left to dry.Dispensing device

[0406] In order to carry out the dyeing process according to the invention which has just been described, a dispensing device is used.

[0407] This dispensing device may in particular have all or some of the following characteristics:

[0408] - the dispensing device comprises a dispensing nozzle comprising at least one outlet orifice;

[0409] - the dispensing device comprises a pump for supplying the dispensing nozzle under pressure;

[0410] - the dispensing device comprises at least one tank and at least one pipe for withdrawing the contents of this tank and recycling it to the dispensing nozzle;

[0411] - the flow rate of liquid dispensed by the dispensing nozzle ranges from 0.01 to 20 l / min, preferably from 0.05 to 15 l / min, more preferentially from 0.1 to 10 l / min.

[0412] Represented inis a dispensing device 10 comprising a dispensing nozzle 11 and a tank 12.

[0413] The tank 12 is provided to contain the dyeing composition (A), in particular at the beginning of the treatment.

[0414] In order to dye a head of hair with the process according to the invention, use is preferably made of a volume of the dyeing composition (A) ranging from 0.05 to 5 litres, preferably from 0.1 to 3 litres, better still from 0.5 to 2 litres.

[0415] At the beginning of a treatment of a whole head of hair, the initial volume of the dyeing composition (A) in the tank 12 is, for example, 1 litre.

[0416] The dispensing device 10 further comprises a collection basin 13 in fluid communication with the tank 12. The collection basin 13 may be of the same type as those used currently in hairdressing salons, being arranged to accommodate the user’s head and enable the treatment of their hair.

[0417] The dispensing nozzle 11 is in the form of a shower head. It comprises a handle enabling the user to grasp it with one hand, and a dispensing head with at least one outlet orifice, preferably several outlet orifices.

[0418] The dispenser device 10 comprises a pump 14 , for example a peristaltic pump, which supplies the dispensing nozzle 11 under pressure by pumping the liquid dyeing composition (A) initially present in the tank 12. The dyeing composition (A) can then be dispensed on the head of hair with the dispensing nozzle 11.

[0419] The pump 14 makes it possible to dispense the dyeing composition (A) on the keratin fibres with a flow rate ranging from 0.01 to 20 l / min, preferably from 0.05 to 15 l / min, more preferentially from 0.1 to 10 l / min.

[0420] After the application of the dyeing composition (A) to the hair, a portion of this liquid composition runs into the collection basin 13 by gravity, then flows, for example via a pipe, into the tank 12 also by gravity. The dyeing composition (A) is thus recovered in step ii) in the tank 12.

[0421] The dyeing composition (A) can be recycled by pumping by means of the pump 14 in order to be dispensed again on the head of hair by the dispensing nozzle 11.

[0422] When the user has obtained satisfactory colouring, after possible rubbing with the hands, they can stop recycling by shutting off the pump.

[0423] The dyeing composition (A) is thus applied continuously to the keratin fibres by means of the dispensing device 10.

[0424] Preferably, the composition (A) is applied continuously for a period of time ranging from 1 to 45 minutes, more preferably from 5 to 30 minutes.

[0425] At the end of the treatment, the user can discharge the dyeing composition (A) remaining in the tank 12 through a discharge orifice, in particular a discharge plug provided in the tank.

[0426] If it is desired to rinse the keratin fibres with the dispensing nozzle 11, the user places water in the tank 12 and once again uses the pump 14 in order to rinse the hair. They may then start this rinsing phase again as many times as necessary, by once again emptying the tank, filling it with water, and starting the operation for pumping the water contained in the tank 12 again in order to pour it over the hair.

[0427] In a variant, the dispensing nozzle 11 may be configured to receive water, in addition to the recycled dyeing composition (A).

[0428] The dispensing nozzle 11 is thus connected firstly to the pump 14 which ensures the recycling and secondly to a supply of running water. A system of valves may be provided to make it possible to open or close the supply and the pipe connecting the dispensing nozzle 11 to the pump 14, depending on the operating phase.

[0429] According to one variant, the hairdresser initially applies the dyeing composition (A) manually to the head of hair, for example using a brush or a bottle, in step i). The tank 12 then contains water which is dispensed on the head of hair with the dispensing nozzle 11, supplied by the pump 14.

[0430] A portion of the dyeing composition (A) rinsed with water runs into the basin 13 by gravity, then flows, for example via a pipe, into the tank 12 also by gravity. It can then be recycled in the same way as before.

[0431] The examples that follow serve to illustrate the invention without, however, being limiting in nature.Examples

[0432] In the examples that follow, all the amounts are given as mass percentages of active material (AM) relative to the total weight of the composition (unless otherwise mentioned).Compositions

[0433] The dyeing composition (A), pretreatment composition (B) and post-treatment composition (C) were prepared from the compounds of which the contents are indicated in the tables below:

[0434] Dyeing composition (A)

[0435] A1A2A3A4A5A5’A6A6’HC BLUE NO. 160.05BASIC YELLOW 870.05BASIC BROWN 170.05ACID YELLOW 230.05ACID RED 520.050.05ACID VIOLET 430.050.05Benzyl alcohol1010pH adjusterqs pHqs pHqs pHqs pHqs pHpH79.57.12.32.42.42.42.4Waterqs 100qs 100qs 100qs 100qs 100qs 100qs 100qs 100

[0436] Pretreatment composition (B)

[0437] BTHIOGLYCOLIC ACID6AMMONIUM HYDROXIDEqs pH = 10 ± 0.3Waterqs 100

[0438] Post-treatment composition (C)

[0439] OHYDROGEN PEROXIDE2.4GLYCEROL1.5BEHENTRIMONIUM CHLORIDE0.8ISOPROPYL ALCOHOL0.2STEARETH-25.0PHOSPHORIC ACIDqs pH = 2.5 ± 0.2Stabilizers, sequestrantsqsWaterqs 100

[0440] Evaluation 1

[0441] The process according to the invention (Protocol 1) comprising the application of a dyeing composition by recirculation by means of the dispensing device, was compared with a process in which the same dyeing composition is applied statically (Protocol 2) to locks of hair containing 90% natural white hair.

[0442] Protocol 1 (invention)

[0443] Use is made of a dispensing device 10 as depicted inwhich delivers 400 ml / min.

[0444] 50 ml of dyeing composition (A1 to A6) are introduced into the tank 12.

[0445] The dyeing composition from the tank is applied using the dispensing nozzle 11 to a lock of hair.

[0446] The dyeing composition is partly recovered in the tank 12 and the dyeing composition is applied once again to the lock.

[0447] The dyeing composition is thus recycled and reapplied continuously for 20 minutes, at room temperature.

[0448] At the end of the 20 minutes, the lock is rinsed with water, then washed with a standard shampoo, and dried in an oven.

[0449] The remaining dyeing composition is discharged from the tank.

[0450] Protocol 2 (comparative)

[0451] A lock of hair is placed in a tank containing 50 ml of dyeing composition (A1 to A6) for 20 minutes, at room temperature.

[0452] After a leave-on time of 20 minutes, the lock is rinsed with water, then washed with a standard shampoo, and dried in an oven.

[0453] The colouring of the locks of hair was then evaluated.

[0454] The colorimetric measurements were performed using a Konica Minolta 3600 spectrocolorimeter (illuminant D65, angle 10°, specular component included) in the CIELab system.

[0455] In this L*a*b* system, L* represents the intensity of the colour, a* indicates the green / red colour axis and b* the blue / yellow colour axis.

[0456] The colouring obtained was evaluated by measuring ΔE, which is the variation in colour before and after the dyeing process, from the formula:

[0457] in which L* represents the intensity and a* and b* represent the chromaticity of the dyed hair, and L0* represents the intensity and a0* and b0* represent the chromaticity of the hair before dyeing. The larger the value ΔE, the greater the colour uptake.

[0458] Results

[0459] L*a*b*ΔEReference NW90Untreated60.210.3811.52A1Protocol 2 (comparative)37.4-6.0-12.934.0Protocol 1 (invention)37.8-5.1-17.637.1A2Protocol 2 (comparative)56.81-1.8953.5642.2Protocol 1 (invention)56.56-0.2058.5847.2A3Protocol 2 (comparative)52.2116.039.8017.7Protocol 1 (invention)45.7211.0424.0821.9A4Protocol 2 (comparative)58.74-0.5625.9814.6Protocol 1 (invention)60.94-1.2731.2119.8A5Protocol 2 (comparative)49.4512.84-3.0422.0Protocol 1 (invention)45.9210.82-6.7725.5A6Protocol 2 (comparative)48.020.01-5.1220.6Protocol 1 (invention)46.120.82-7.3023.5

[0460] The locks of hair treated with the recirculation dyeing process according to the invention have a higher ΔE value than those treated with the comparative dyeing process without recirculation.

[0461] In other words, the process according to the invention makes it possible to obtain a better uptake of the dyes than the comparative process.

[0462] Evaluation 2

[0463] The process according to the invention (Protocol 1) comprising the application of dyeing compositions A’5 and A’6 in recirculation mode, was compared with a process in which the same dyeing compositions are applied in static mode (Protocol 2) to other locks of hair containing 90% natural white hair.

[0464] Results

[0465] L*a*b*ΔEReference NW90Untreated63.71-0.3712.32A5’Protocol 2 (comparative)30.9737.51-17.9358.5Protocol 1 (invention)24.3229.06-23.0960.6A6’Protocol 2 (comparative)43.072.36-14.1733.7Protocol 1 (invention)24.7912.58-28.7658.0

[0466] The locks of hair treated with the recirculation dyeing process according to the invention have a higher ΔE value than those treated with the comparative dyeing process without recirculation.

[0467] In other words, the process according to the invention makes it possible to obtain a better uptake of the dyes than the comparative process.

[0468] Evaluation 3

[0469] The process according to the invention (Protocol 1’) comprising the application of a dyeing composition in recirculation mode, was compared with a process in which the same dyeing composition is applied in static mode (Protocol 2’).

[0470] Protocols 1’ and 2’ correspond respectively to protocols 1 and 2 with, in addition, a step of pretreatment of the locks with the pretreatment composition (B) and a step of post-treatment with the post-treatment composition (C).

[0471] Pretreatment step: composition (B) was withdrawn and deposited on a lock of hair using a pipette in a proportion of 2 g of composition (B) per 1 g of lock of hair. Composition (B) was distributed over the lock using a brush. Composition B is left on the hair for 5 minutes and then rinsed with water.

[0472] The lock was then treated according to protocols 1 and 2 respectively.

[0473] Post-treatment step: the post-treatment composition (C) was applied to the lock of hair in a proportion of 2 g of composition (C) per 1 g of lock of hair. Composition (C) was distributed over the lock using a brush. Composition (C) is left on the hair for 5 minutes, then rinsed with water, the hair then being washed with a shampoo.

[0474] The colouring was then evaluated by measuring ΔE corresponding to the variation in the colour before and after the dyeing process.

[0475] Results

[0476] L*a*b*ΔEReference NW90Untreated63.71-0.3712.32A5Protocol 2’ (comparative)37.2340.84-16.5656.9Protocol 1’ (invention)34.0543.28-18.5161.1A6Protocol 2’ (comparative)33.677.64-24.0447.8Protocol 1’ (invention)31.339.12-26.7151.6

[0477] The locks of hair treated with the recirculation dyeing process according to the invention have a higher ΔE value than those treated with the comparative dyeing process without recirculation.

[0478] In other words, the process according to the invention makes it possible to obtain a better uptake of the dyes than the comparative process.

[0479] Evaluation 4

[0480] Compositions A1 to A6 were also applied to the entire head of hair of a mannequin head comprising hair containing 90% natural white hair, according to the process of the invention with the dispensing device 10 as depicted in. The flow rate of the dispensing device 10 is this time 8 l / min.

[0481] One litre of dyeing composition (A1 to A6) is introduced into the tank 12.

[0482] The dyeing composition is applied, recovered and reapplied continuously for 10 to 20 minutes, depending on the compositions, at room temperature.

[0483] A portion of the composition is withdrawn every 5 minutes in order to visually evaluate its dye content.

[0484] It is found that each dye composition clarifies starting from the first minutes. In particular, a distinct depletion in dye is observed between 2 and 15 minutes for each of compositions A1 to A6.

[0485] In addition, each of compositions A1 to A6 results in good colouring of the hair.

[0486] The process according to the invention thus makes it possible to dye the hair efficiently while reducing the amount of dyes in the rinsing waters.

Claims

Process for dyeing keratin fibres, in particular human keratin fibres such as the hair, comprising:i) applying to said keratin fibres a dyeing composition (A) comprising one or more direct dyes and optionally water,ii) recovering at least one portion of the dyeing composition (A) after applying to said keratin fibres,iii) applying the dyeing composition (A) recovered in step ii) to said keratin fibres,iv) optionally rinsing the keratin fibres with water.Dyeing process according to the preceding claim which comprises i) applying to said keratin fibres a dyeing composition (A) comprising one or more direct dyes and water.Dyeing process according to either one of the preceding claims, in which the dyeing composition (A) applied in step i) comprises less than 1% by weight of fatty substance, preferably less than 0.5% by weight relative to the total weight of the dyeing composition (A), and better still does not contain any fatty substance.Dyeing process according to either one of the preceding claims, in which steps ii) and iii) are repeated at least once, preferably several times, better still are carried out continuously, before the optional rinsing step iv).Dyeing process according to any one of the preceding claims, in which step iii) of applying the recovered dyeing composition (A) is carried out using a dispensing device (10) comprising a pump (14) for supplying a dispensing nozzle (11).Dyeing process according to the preceding claim, in which step i) of applying the dyeing composition (A) is carried out using a dispensing device (10) comprising a pump (14) for supplying a dispensing nozzle (11) under pressure.Dyeing process according to any one of the preceding claims, in which the composition (A) is recovered in step ii) in a tank (12).Dyeing process according to any one of Claims 2 to 7 using a volume of the dyeing composition (A) ranging from 0.05 to 5 l, preferably from 0.1 to 3 l, better still from 0.5 to 2 l.Dyeing process according to any one of Claims 5 to 8, in which the dyeing composition (A) is applied to the keratin fibres in step iii) and optionally in step i) through the dispensing nozzle (11) with a flow rate ranging from 0.01 l / min to 20 l / min, preferably from 0.05 l / min to 15 l / min, more preferentially from 0.1 l / min to 10 l / min.Dyeing process according to any one of the preceding claims, in which steps i) to iii) are carried out for a period of time ranging from 1 to 45 minutes, preferably from 5 to 30 minutes.Dyeing process according to any one of the preceding claims, in which the total content of the direct dye(s) in the dyeing composition (A) applied in step i) ranges from 0.001% to 10%, preferably from 0.005% to 5% by weight, more preferentially from 0.01% to 2% by weight, better still from 0.02% to 1% by weight, relative to the total weight of the dyeing composition (A).Dyeing process according to any one of Claims 2 to 11, in which the total content of water in the dyeing composition (A) applied in step i) ranges from 80% to 99.999% by weight, preferably from 85% to 99.995% by weight, more preferably from 90% to 99.99% by weight, more preferentially from 95% to 99.98% by weight, relative to the total weight of the composition (A).Dyeing process according to the preceding claim, in which the direct dye(s) are chosen from anionic direct dyes, cationic direct dyes and nonionic direct dyes.Dyeing process according to any one of the preceding claims, in which the direct dye(s) are chosen from cationic direct dyes, preferably chosen from azo cationic direct dyes, hydrazono cationic direct dyes, anthraquinone cationic direct dyes, triarylmethane cationic direct dyes, and mixtures thereof.Dyeing process according to any one of the preceding claims, in which the direct dye(s) are chosen from anionic direct dyes, preferably from acid azo direct dyes, acid azine direct dyes, acid triarylmethane direct dyes, acid indoamine direct dyes, acid anthraquinone direct dyes, acid indigoid direct dyes, acid natural direct dyes, and mixtures thereof.Dyeing process according to any one of the preceding claims, in which the dyeing composition (A) comprises one or more organic solvents chosen from aromatic alcohols and alkylene carbonates, preferably chosen from benzyl alcohol, phenethyl alcohol, cinnamic alcohol, phenyl propyl alcohol, 1-phenoxy-2-propanol, phenyl diglycol, α-methylbenzyl alcohol, dimethyl benzyl carbinol, benzyloxyethanol, phenoxyethanol, phenoxyisopropanol, p-anisyl alcohol, ethylene carbonate and propylene carbonate.Dyeing process according to the preceding claim, in which the total content of organic solvents chosen from aromatic alcohols and alkylene carbonates in composition (A) applied in step i) ranges from 0.1% to 20% by weight, preferably from 0.5% to 15% by weight, more preferentially from 1% to 13% by weight relative to the total weight of the dyeing composition (A).Dyeing process according to any one of the preceding claims, in which the dyeing composition (A) applied in step i) comprises less than 1% by weight of surfactant and / or thickening agent, preferably less than 0.5% by weight, relative to the total weight of the dyeing composition (A), and better still does not contain any surfactant and / or thickening agent.Dyeing process according to any one of the preceding claims, which comprises, before step i) of applying the dyeing composition (A), the application of a pretreatment composition (B) comprising one or more reducing agents, preferably chosen from thiol-based reducing agents, sulfites, bisulfites, sulfinates, phosphines, reducing sugars, mineral and / or organic salts thereof, and mixtures thereof, preferably thiol-based reducing agents, phosphines, mineral and / or organic salts thereof, and mixtures thereof, and preferentially from thiol-based reducing agents, mineral and / or organic salts thereof and mixtures thereof, better still from thioglycolic acid, mineral and / or organic salts thereof, and mixtures thereof.Dyeing process according to the preceding claim, in which the pretreatment composition (B) has a pH of greater than or equal to 7, preferably ranging from 8 to 12, preferentially from 9 to 11, better still from 9.5 to 10.5.Dyeing process according to any one of the preceding claims, which comprises, after step iii) or after the optional rinsing step iv),v) a step of applying a post-treatment composition (C) comprising one or more chemical oxidizing agent(s), preferably chosen from hydrogen peroxide, urea peroxide, alkali metal bromates or ferricyanides, peroxygenated salts such as alkali metal or alkaline-earth metal persulfates, perborates and percarbonates, and peracids and precursors thereof; the oxidizing agent preferably being hydrogen peroxide.

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