Process for Dyeing and Relaxing Curls of Keratin Fibres, Using Reducing Agents and Hair Dyes, and Associated Kit

Abstract

The present invention relates to a process for dyeing and relaxing curls of keratin fibres, such as the hair, which comprises the application to the fibres of one or more acidic compositions comprising reducing agents and of one or more compositions comprising hair-dyeing agents, and a step of heat treatment of the fibres by means of a heating tool. A subject of the invention is also the use of the composition(s) comprising reducing agents and of the composition(s) comprising hair-dyeing agents in a process for dyeing and relaxing curls of keratin fibres. Finally, a subject of the invention is a multi-compartment device or kit suitable for carrying out such a process.

Claims

1. Process for dyeing and relaxing the curls of keratin fibres, in particular of keratin fibres such as the hair, comprising: i) the application to said fibres of an acidic composition (A) having a pH of inclusively between 1 and 5 and containing one or more thiol-comprising reducing agents; ii) the application to said fibres of a distinct composition (B) containing one or more dyes chosen from a) direct dyes and b) oxidation dyes; followed iii) by a step of heat treatment of the fibres by means of a heating tool; it being understood that steps i) and ii) are carried out separately, i.e. i) then ii) or else ii) then i) or together on the keratin fibres, preferably in the order i) then ii) and followed by step iii).

2. Process according to claim 1, comprising a step o) of using a composition (C) containing one or more non-thiol-comprising reducing agents after step i) and/or ii) and before the heat treatment step iii).

3. Process according to claim 1, characterized in that the thiol-comprising reducing agent(s) is (are) chosen from those of formulae i-1 and i-2, and also the organic or mineral acid or base salts thereof, optical isomers thereof and tautomers thereof, and the solvates such as hydrates:
RSHi-1
RSRi-2 In which formulae i-1 and i-2: R represents a linear or branched (C1-C5)alkyl, preferably (C.sub.1-C.sub.6)alkyl, group which is optionally substituted, preferably substituted, with one or more groups chosen from carboxy C(O)OH, (di)(C.sub.1-C.sub.4)(alkyl)amino, hydroxyl OH and thiol SH, and/or optionally interrupted with one or more heteroatoms or groups chosen from O, S, N(R) wherein R represents a hydrogen atom or a linear or branched (C.sub.1-C.sub.4)alkyl group, C(O) or combinations thereof such as OC(O), C(O)O, N(R)C(O) or C(O)N(R); a (hetero)aryl group optionally substituted in particular with one or more hydroxyl, thiol or carboxy groups; R and R, which may be identical or different, represent a (C.sub.1-C.sub.8)alkyl group, preferably (C.sub.1-C.sub.6)alkyl group, substituted with one or more groups chosen from hydroxyl, thiol and carboxy; or else R and R form, together with the sulfur atom which bears them, a heterocyclic group, comprising from 5 to 7 ring members, which is preferably saturated, which comprises from 1 to 3 heteroatoms, and which is optionally substituted (in particular with one or more (C.sub.1-C.sub.6)alkyl groups optionally substituted with one or more hydroxyl, thiol or carboxy groups), more preferentially the heterocyclic group is a dithiolane group optionally substituted with a (C.sub.1-C.sub.6)alkyl group optionally substituted with one or more carboxy groups.

4. Process according to claim 3, characterized in that the thiol-comprising reducing agent(s) is (are) chosen from those of formula i-1 for which R represents a linear or branched (C.sub.1-C.sub.8)alkyl group, preferably (C.sub.1-C.sub.6)alkyl group, substituted with one or more groups chosen from carboxy C(O)OH, amino, hydroxyl OH, and thiol SH; and/or optionally interrupted with one or more heteroatoms or groups chosen from O, N(R) wherein R represents a hydrogen atom or a linear or branched (C.sub.1-C.sub.4)alkyl group, C(O) or combinations thereof such as OC(O), C(O)O, N(R)C(O), or C(O)N(R), preferably an uninterrupted linear or branched (C.sub.1-C.sub.8)alkyl group, more preferentially (C.sub.1-C.sub.6)alkyl group.

5. Process according to claim 3, characterized in that the thiol-comprising reducing agent(s) is (are) chosen from those of formula i-1 for which R represents: a phenyl group optionally substituted with one or more hydroxyl, thiol or carboxy groups; or a heteroaryl comprising from 5 to 10 ring members, which is preferably bicyclic comprising 9 or 10 ring members, comprising from 1 to 4 heteroatoms chosen from O, S or N, preferably N, optionally substituted with one or more hydroxyl or thiol groups.

6. Process according to claim 3, characterized in that the thiol-comprising reducing agent(s) is (are) chosen from those of formula i-2 for which R and R, which may be identical or different, represent a (C.sub.1-C.sub.8)alkyl group, preferably (C.sub.1-C.sub.6)alkyl group, substituted with one or more groups chosen from hydroxyl, thiol, and carboxy.

7. Process according to claim 1, characterized in that the thiol-comprising reducing agent(s) is (are) chosen from thioglycolic acid, thiolactic acid, cysteine, cysteamine, homocysteine, glutathione, thioglycerol, thiomalic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, thiodiglycol, 2-mercaptoethanol, dithiothreitol, thioxanthine, thiosalicylic acid, thiodiglycolic acid, lipoic acid, N-acetylcysteine, and thioglycolic or thiolactic acid esters and amides, in particular glyceryl monothioglycolate, and mixtures of these compounds, preferably thioglycolic acid.

8. Process according to claim 1, characterized in that the dye(s) is (are) chosen from a) direct dyes in particular chosen from cationic and non-ionic, preferably cationic, direct dyes.

9. Process according to claim 1, characterized in that the dyes are chosen from the following dyes: mono- or dichromophore dyes having the formulae below:
A-(X).sub.pC.sub.satH(XXVI)
A-(X).sub.pC.sub.sat(X).sub.p-A(XXVI) the organic or mineral acid salts, optical isomers and geometric isomers thereof, and the solvates such as hydrates; in which formula (XXVI) or (XXVI): A, and A, which may be identical or different, represent a chromophore which is preferably fluorescent and cationic or non-cationic; X and X, which may be identical or different, represent a linear or branched, saturated or unsaturated C.sub.1-C.sub.30 hydrocarbon-based chain, optionally interrupted and/or optionally terminated at one or both of its ends with one or more divalent groups or heteroatoms or combinations thereof chosen from: N(R), N.sup.+(R)(R), O, S, C(O), SO.sub.2 with R, which may be identical or different, chosen from a hydrogen and a C.sub.1-C.sub.4 alkyl, hydroxyalkyl or aminoalkyl radical; the indices p and p, which may be identical or different, are equal to 0 or 1; C.sub.sat represents a linear or branched C.sub.1-C.sub.18 alkylene chain, optionally substituted, and/or optionally interrupted with one or more divalent groups or heteroatoms or combinations thereof chosen from: N(R), N.sup.+(R)(R), O, S, C(O), SO.sub.2 with R, which may be identical or different, chosen from a hydrogen and a C.sub.1-C.sub.4 alkyl, hydroxyalkyl or aminoalkyl radical; More particularly, A and A, which may be identical or different, more preferentially identical, represent WC(R.sup.c)C(R.sup.d)Ar* or *WC(R.sup.c)C(R.sup.d)Ar, preferably *WC(R.sup.c)C(R.sup.d)Ar, with W representing a heterocycle or a heteroaryl, comprising a quaternary ammonium; Ar represents a 5- or 6-membered (hetero)aryl radical of phenyl or pyridium type, or a (hetero)aromatic bicycle of naphthyl, benzopyridnium, indolinyl or benzoindolinyl type optionally substituted with one or more halogen atoms; with one or more alkyl groups; with one or more hydroxyl groups; with one or more alkoxy groups, with one or more hydroxyalkyl groups, with one or more amino or (di)alkylamino groups, with one or more acylamino groups; with one or more 5- or 6-membered heterocycloalkyl or heteroaryl groups; R.sup.c and R.sup.d, which may be identical or different, represent a hydrogen atom or a C.sub.1-C.sub.4 alkyl group; more preferentially, W represents an imidazolium, pyridinium, benzopyridinium, benzimidazolium, quinolinium or pyrazolium; Preferably, the dye(s) are chosen from the dyes of formula (XXVII) ##STR00029## in which compound of formula (XXVII): J represents a hydrogen atom or the group (XXVIIa) below: ##STR00030## G and G, which may be identical or different, represent an NR.sub.cR.sub.d or NR.sub.cR.sub.d group, or a (C.sub.1-C.sub.6)alkoxy group, preferably a di(hydroxy)(C.sub.1-C.sub.4)alkylamino group; ALK represents a (C.sub.1-C.sub.6)alkylene chain optionally interrupted with one or more divalent heteroatoms or groups or combinations thereof chosen from N(R), O, S and C(O), with R, which may be identical or different, chosen from a hydrogen and a C.sub.1-C.sub.4, alkyl radical; R.sub.g, R.sub.g, R.sub.g, R.sub.g, R.sub.h, R.sub.h, R.sub.h, and R.sub.h, which may be identical or different, represent a hydrogen atom, a halogen atom, an amino, C.sub.1-C.sub.4 alkylamino, C.sub.1-C.sub.4 dialkylamino, carboxy or hydroxyl group, or a C.sub.1-C.sub.4 alkyl radical optionally substituted with a group chosen from C.sub.1-C.sub.4 alkoxy and hydroxy; or else two groups R.sub.g and R.sub.g; R.sub.g and R.sub.g; R.sub.h and R.sub.h; R.sub.h et R.sub.h, borne by two adjacent carbon atoms, together form a benzo or indeno ring, or a fused heterocycloalkyl or fused heteroaryl group; or else G represents NR.sub.cR.sub.d and G represents NR.sub.cR.sub.d and two groups R.sub.c and R.sub.g; R.sub.c and R.sub.g; R.sub.d and R.sub.g; R.sub.d and R.sub.g together form a saturated heteroaryl or heterocycle, optionally substituted with a C.sub.1-C.sub.6 alkyl group; preferably, R.sub.g; R.sub.c and R.sub.g; R.sub.d and R.sub.g; R.sub.d and R.sub.g represent a hydrogen atom; R.sub.i, R.sub.i, R.sub.i, and R.sub.i, which may be identical or different, represent a hydrogen atom or a C.sub.1-C.sub.4 alkyl group; R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.1, R.sub.2, R.sub.3 and R.sub.4, which may be identical or different, represent a hydrogen atom or a group (C.sub.1-C.sub.4)alkyl; T.sub.a et T.sub.b, which may be identical or different, represent i) either a covalent a bond, ii) or one or more radicals or combinations thereof chosen from SO.sub.2, O, S, N(R), N.sup.+(R)(R.sup.o) and CO, with R and R.sup.o, which may be identical or different, representing a hydrogen atom, a C.sub.1-C.sub.4 alkyl or C.sub.1-C.sub.4 hydroxyalkyl radical; or an aryl(C.sub.1-C.sub.4)alkyl, preferably T.sub.a and T.sub.b represent a covalent bond; ##STR00031## represent an aryl or heteroaryl group which is fused to the phenyl ring; or else is absent from the phenyl ring; preferably absent; m and m, which may be identical different, represent an integer between 1 and 6 inclusively; M representing an anionic counterion or an organic or mineral acid salt; the nitrobenzene direct dyes preferably chosen from the compounds of formula (XXIX) below: ##STR00032## In which formula (XXIX): R.sub.18 represents an amino radical; an amino radical monosubstituted or disubstituted with a C.sub.1-C.sub.4 alkyl, C.sub.1-C.sub.4 monohydroxyalkyl, C.sub.2-C.sub.4 polyhydroxyalkyl, C.sub.1-C.sub.4 aminoalkyl, mono(C.sub.1-C.sub.4)alkylamino(C.sub.1-C.sub.4)alkyl, di(C.sub.1-C.sub.4)alkylamino(C.sub.1-C.sub.4)alkyl, C.sub.1-C.sub.4 ureidoalkyl, aryl radical, aryl radical in which the aryl ring is substituted with one or more hydroxyl, carboxyl, amino or di(C.sub.1-C.sub.4)alkylamino radicals, preferably R.sub.18 represents a (di)(C.sub.1-C.sub.4)(alkyl)amino group; preferably, R.sub.18 is in position 2 or 4; R.sub.19 represents a hydrogen atom; an amino radical; a hydroxyl radical; a C.sub.1-C.sub.4 alkyl radical; a C.sub.1-C.sub.4 alkoxy radical; a C.sub.1-C.sub.4 monohydroxyalkyl radical; a C.sub.2-C.sub.4 polyhydroxyalkyl radical; a C.sub.1-C.sub.4 monohydroxyalcoxy radical; a C.sub.2-C.sub.4 polyhydroxyalcoxy radical; a C.sub.1-C.sub.4 aminoalkoxy radical; an amino radical monosubstituted or disubstituted with a C.sub.1-C.sub.4 alkyl, C.sub.1-C.sub.4 monohydroxyalkyl, C.sub.2-C.sub.4 polyhydroxyalkyl, C.sub.1-C.sub.4 aminoalkyl, mono(C.sub.1-C.sub.4)alkylamino(C.sub.1-C.sub.4)alkyl, di(C.sub.1-C.sub.4)alkylamino(C.sub.1-C.sub.4)alkyl, C.sub.1-C.sub.4 ureidoalkyl, or aryl radical, in which aryl radical the aryl ring is substituted with one or more hydroxyl, carboxyl, amino or di(C.sub.1-C.sub.4)alkylamino radicals; preferably, R.sub.19 represents a hydrogen atom or a hydroxy or (di)(C.sub.1-C.sub.4)(alkyl)amino group; preferably, R.sub.19 is in position 4 or 6; R.sub.20 represents a hydrogen or halogen atom, a C.sub.1-C.sub.4 alkyl radical or a nitro group; preferably, R.sub.20 represents a hydrogen atom.

10. Process according to claim 1, characterized in that the dye(s) is (are) chosen from anionic direct dyes; preferably from anionic direct azo dyes, such as the diaryl anionic azo dyes of formulae (II) or (III): ##STR00033## in which formulae (II) and (III): R.sub.7, R.sub.8, R.sub.9, R.sub.10, R.sub.7, R.sub.8, R.sub.9 and R.sub.10, which may be identical or different, represent a hydrogen atom or a group chosen from: alkyl; alkoxy, alkylthio; hydroxyl, mercapto; nitro, nitroso; R.sup.oC(X)X, R.sup.oXC(X), R.sup.oXC(X)X with R.sup.o 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; (O).sub.2S(O.sup.), M.sup.+ with M.sup.+ representing a hydrogen atom or a cationic counterion; (O)CO.sup., M.sup.+ with M.sup.+ as defined previously; RS(O).sub.2, with R representing a hydrogen atom or an alkyl, aryl, (di)(alkyl)amino or aryl(alkyl)amino group; preferentially a phenylamino or phenyl group; RS(O).sub.2X with R representing an alkyl or optionally substituted aryl group, X as defined previously; (di)(alkyl)amino; aryl(alkyl)amino optionally substituted with one or more groups chosen from i) nitro; ii) nitroso; iii) (O).sub.2S(O.sup.), M.sup.+ and iv) alkoxy, with M.sup.+ as defined previously; optionally substituted heteroaryl; preferentially a benzothiazolyl group; cycloalkyl; in particular cyclohexyl; ArNN with Ar representing an optionally substituted aryl group; preferentially a phenyl optionally substituted with one or more alkyl, (O).sub.2S(O), M+ or phenylamino groups; or alternatively two contiguous groups R.sub.7 with R.sub.8 or R.sub.8 with R.sub.9 or R.sub.9 with R.sub.10 together form a fused benzo group A; and R.sub.7 with R.sub.8 or R.sub.8 with R.sub.9 or R.sub.9 with R.sub.10 together 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).sub.2S(O), M+; iv) hydroxyl; v) mercapto; vi) (di)(alkyl)amino; vii) R.sup.o C(X)X; viii) R.sup.oXC(X); ix) R.sup.oXC(X)X; x) ArNN and xi) optionally substituted aryl(alkyl)amino; with M.sup.+, R.sup.o, X, X, X and Ar previously defined; W represents a sigma bond 6, an oxygen or sulfur atom, or a divalent radical i) NR with R as defined previously, or ii) methylene C(R.sub.a)(R.sub.b) with R.sub.a and R.sub.b, which may be identical or different, representing a hydrogen atom or an aryl group, or alternatively R.sub.a and R.sub.b form, with the carbon atom that bears them, a spiro cycloalkyl; preferentially, W represents a sulfur atom or R.sub.a and R.sub.b together form a cyclohexyl; it being understood that formulae (II) and (III) comprise at least one sulfonate radical (O).sub.2S(O.sup.), M.sup.+ or one carboxylate radical (O)CO.sup., M.sup.+ on one of the rings A, A, B, B or C; preferentially sodium sulfonate; more preferably from anionic direct azo dyes of formula (II) such as the acid Red 18.

11. Process according to claim 2, characterized in that the non-thiol-comprising reducing agent(s) is (are) chosen from ortho-diphenol derivatives and preferably from the compounds of formula (XXXI) ##STR00034## in which formula (XXXI) the substituents: R.sub.1 to R.sub.4, which may be identical or different, represent: a hydrogen atom, a halogen atom, a hydroxyl radical, a carboxyl radical; an alkyl carboxylate or alkoxycarbonyl radical, an optionally substituted amino radical, an optionally substituted and linear or branched alkyl radical, an optionally substituted and linear or branched alkenyl radical, an optionally substituted cycloalkyl radical, an alkoxy radical, an alkoxyalkyl radical, an alkoxyaryl radical, it being possible for the aryl group to be optionally substituted, an aryl radical, a substituted aryl radical, a saturated or unsaturated heterocyclic radical carrying or not carrying a cationic or anionic charge, optionally substituted and/or optionally fused with an aromatic ring, preferably a benzene ring, said aromatic ring being optionally substituted, in particular with one or more hydroxyl or glycosyloxy groups, a radical containing one or more silicon atoms, or two of the substituents carried by two adjacent carbon atoms R.sub.1-R.sub.2, R.sub.2-R.sub.3 or R.sub.3-R.sub.4 form, together with the carbon atoms carrying them, a saturated or unsaturated and aromatic or non-aromatic ring, optionally comprising one or more heteroatoms and optionally fused with one or more saturated or unsaturated rings optionally comprising one or more heteroatoms.

12. Process according to claim 2, characterized in that the non-thiol-comprising reducing agent(s) is (are) chosen from meta-hydroxyphenol derivatives, and preferably from the compounds of formula (XXXII), and also the organic or mineral acid or base salts thereof, and the solvates thereof such as hydrates: ##STR00035## in which formula (XXXII) the substituents: R.sub.1, R.sub.2 and R.sub.4, which may be identical or different, represent: a hydrogen atom, a halogen atom, a carboxyl radical, an alkyl carboxylate or alkoxycarbonyl radical, an optionally substituted amino radical, an optionally substituted and linear or branched alkyl radical, an optionally substituted and linear or branched alkenyl radical, an optionally substituted cycloalkyl radical, an alkylcarbonyl radical, a carboxaldehyde radical, an alkoxy radical, an alkoxyalkyl radical, an alkoxyaryl radical, it being possible for the aryl group to be optionally substituted, an arylalkylcarbonyl radical of which the aryl group, particularly phenyl group, is optionally substituted, preferably with one or more hydroxyl groups, an aryl radical, a substituted aryl radical, a saturated or unsaturated heterocyclic radical carrying or not carrying a cationic or anionic charge, optionally substituted and/or optionally fused with an aromatic ring, preferably a benzene ring, said aromatic ring being optionally substituted, in particular with one or more hydroxyl or glycosyloxy groups, a radical containing one or more silicon atoms, R.sub.3 represents: a hydrogen atom, a halogen atom, a hydroxyl radical, a carboxyl radical, an alkyl carboxylate or alkoxycarbonyl radical, an optionally substituted amino radical, an optionally substituted and linear or branched alkyl radical, a linear or branched alkenyl radical which is optionally substituted, in particular with a phenyl group which is preferably optionally substituted with one or more (di)(C.sub.1-C.sub.4)(alkyl)amino, or hydroxyl groups, an optionally substituted cycloalkyl radical, an alkylcarbonyl radical, a carboxaldehyde radical, an alkoxy radical, an alkoxyalkyl radical, an alkoxyaryl radical, it being possible for the aryl group to be optionally substituted, an aryl radical, a substituted aryl radical, a saturated or unsaturated heterocyclic radical carrying or not carrying a cationic or anionic charge, optionally substituted and/or optionally fused with an aromatic ring, preferably a benzene ring, said aromatic ring being optionally substituted, in particular with one or more hydroxyl or glycosyloxy groups, a radical containing one or more silicon atoms, or two of the substituents borne by two adjacent carbon atoms R.sub.2-R.sub.3 or R.sub.3-R.sub.4 form, together with the carbon atoms carrying them, a saturated or unsaturated and non-aromatic ring, optionally comprising one or more heteroatoms and optionally fused with one or more saturated or unsaturated rings optionally comprising one or more heteroatoms; particularly, R.sub.1, R.sub.2 and R.sub.4 represent a hydrogen atom or an optionally substituted (C.sub.1-C.sub.6)alkyl group, preferably hydrogen, and/or R.sub.3 represents a hydrogen atom or a linear or branched (C.sub.1-C.sub.6)alkyl or (C.sub.2-C.sub.6)alkenyl group, such as ethenyl, optionally substituted with an aryl group, such as a phenyl group, which is optionally substituted, preferably with one or more (di)(C.sub.1-C.sub.4)(alkyl)amino, or hydroxyl groups; more particularly, R.sub.1, R.sub.2 and R.sub.4 represent a hydrogen atom or a (C.sub.1-C.sub.4)alkyl group, preferably hydrogen, and R.sub.3 represents a hydrogen atom or an ArCHCH group with Ar representing an aryl group, in particular a phenyl group, said aryl group being optionally substituted, preferably with one or more hydroxyl groups; in particular said hydroxyl group(s) is (are) substituted in the ortho or para position with respect to the phenyl group.

13. Process according to claim 2, characterized in that the non-thiol-comprising reducing agent(s) is (are) chosen from para-hydroxyphenol derivatives, and preferably from the compounds of formula (XXXIII), and also the organic or mineral acid or base salts thereof, and the solvates thereof such as hydrates: ##STR00036## in which formula (XXXIII) R.sup.1 to R.sup.4, which may be identical or different, are as defined for formula (XXXI) or (XXXII) in claims 11 and 12, preferably represent a hydrogen atom or an optionally substituted (C.sub.1-C.sub.4)alkyl group, preferably hydrogen.

14. Process according to claim 2, characterized in that the non-thiol-comprising reducing agent(s) is (are) chosen from catechol, gallic acid, para-hydroxyphenol, resveratrol and mixtures thereof.

15. Process according to claim 1, characterized in that the thiol-comprising reducing agent(s) represent(s) from 0.02% to 5% by weight and preferably from 0.1% to 3% by weight relative to the total weight of the composition (A).

16. Process according to claim 1, characterized in that the dyeing agent(s) a) represent(s) at least 0.1% by weight, preferably at least 0.5% by weight, more preferentially from 0.5% to 5% by weight, relative to the total weight of the composition.

17. Process according to claim 2, characterized in that the non-thiol-comprising reducing agent(s) represent(s) from 1% to 10% by weight and preferably from 2% to 8% by weight relative to the total weight of the composition (C).

18. Process according to claim 2, characterized in that the ratio between the amount of thiol-comprising reducing agent(s) and the amount of non-thiol-comprising reducing agent(s) is between 0.01 and 10, particularly inclusively between 0.1 and 5, and more preferentially inclusively between 0.2 and 1.

19. Process according to claim 1, characterized in that it comprises a step of rinsing the keratin fibres after step i) and/or step ii) and before the heat treatment step (iii).

20. Process according to claim 1, characterized in that it comprises: i) the application to the fibres of a composition (A) comprising said thiol-comprising reducing agent(s), then ii) the application to the fibres of a composition (B) comprising said direct dye(s), an optional step of rinsing the fibres, then iii) a step of heat treatment of the fibres by means of a heating tool.

21. Process according to claim 20, characterized in that it comprises, between steps i) and ii): o) the application to the fibres of a composition (C) comprising said non-thiol-comprising reducing agent(s).

22. Process according to claim 1, characterized in that the heat treatment step iii) is carried out by means of a heating tool chosen from a hairstyling hood, a straightening iron, a hairdryer and an infrared-ray dispenser, preferably a straightening iron.

23. Process according to claim 1, characterized in that the heat treatment step is carried out at a temperature ranging from 30 to 250 C., preferably from 60 to 230 C. and more preferentially from 100 to 150 C.

24. Acidic composition having a pH of inclusively between 1 and 5, and containing one or more thiol-comprising reducing agents, and one or more dyes chosen from a) direct dyes and b) oxidation dyes in the absence of chemical oxidizing agent, and one or more non-thiol-comprising reducing agents.

25. Kit comprising at least two compartments: a first compartment comprising an acidic composition (A) which comprises one or more thiol-comprising reducing agents, a second compartment comprising a composition (B) which comprises one or more direct dyes, and optionally a third compartment comprising a composition (C) which comprises one or more non-thiol-comprising reducing agents.

Description

EXAMPLES

Example 1

[0761] a) Protocol for Preparing the Compositions Used in the Process of the Invention:

[0762] Thiolactic acid is tested comparatively in solution at 1% and 8% by weight in water at pH 3.5.

[0763] Para-hydroxyphenol is tested in solution at 5% by weight in water at pH 3.5.

[0764] The following dyes 1 to 3 were tested in solution at 0.5% by weight in water: Cationic dye 1: 4-[(2-{4-[bis(2-hydroxyethyl)amino]phenyl}ethenyl]-1-hexylpyridinium bromide

##STR00026##

Cationic Dichromophore Dye 2:

[0765] ##STR00027##

Neutral Direct Dye 3: 4-Amino-3-Nitrophenol

[0766] b) Protocol for Evaluating the Technical Effect (Colour, Stability, Performance During/after Application)

[0767] b1) Each composition prepared in the previous preparation protocol a) was tested on natural locks containing 90% grey hairs according to dyeing/curl relaxing/straightening treatment protocols.

[0768] b2) Protocol for Brazilian straightening with conventional iron:

[0769] The locks of keratin fibres were combed, then were subjected to 10 successive blow drying passes, at position 2 (80 C.) of the hairdryer, with a round brush of medium diameter. Each of the locks was then separated into 2. Each part was subjected to 10 passes with the straightening iron using a comb on each half, then passes over all of it at 230 C.

[0770] The locks were then washed with a mild shampoo, and dried.

[0771] c) Sensory Results of the Evaluation In Vitro

[0772] The dyed locks are subjected to 1, 10 and 20 shampooing operations according to a cycle that includes wetting the locks with water, washing with shampoos, rinsing with water followed by a drying operation.

[0773] The colour of the locks before and after washing is evaluated in the L* a* b* system, using a Minolta CM 2002 spectrophotometer (Illuminant D65).

[0774] In the L* a* b* system, the three parameters denote respectively the intensity (L*), the shade (a*) and the saturation (b*). According to this system, the higher the value of L, the lighter or less intense is the colour. Conversely, the lower the value of L, the darker or very intense is the colour. a* and b* indicate two colour axes, a* indicates the green/red colour axis and b* indicates the blue/yellow colour axis.

[0775] The chromaticity is calculated from the measurements of a* and of b* according to the following formula:

C*={square root over (a*.sup.2+b*.sup.2)}

[0776] The higher the value of C*, the more chromatic is the colour.

[0777] The locks of hair were treated in the following way:

[0778] Lock 1 was treated with a solution containing thiolactic acid at 8% and a dye for 30 min, then rinsed, followed by a step of blow-drying and passing the iron over at 230 C.

[0779] Lock 2 was treated with a solution of thiolactic acid at 1% for 30 min, then a dyeing solution is applied for 20 min, then a solution of para-hydroxyphenol at 5% is applied for 20 min, followed by a step of blow-drying and passing the iron over at 230 C.

[0780] Lock 3 was treated with a solution of thiolactic acid at 1% for 30 min, then a solution of para-hydroxyphenol at 5% is applied for 20 min, then a dyeing solution is applied for 20 min, followed by a step of blow-drying and passing the iron over at 230 C.

[0781] Lock 4 was treated with a solution containing thiolactic acid at 1% and a dyeing solution for 30 min, then a solution of para-hydroxyphenol at 5%, followed by a step of blow-drying and passing the iron over at 230 C.

[0782] The chromaticity results are grouped together in the table below at 1 and 20 successive shampooing operations:

TABLE-US-00002 Lock before treatment C* 13.81 C*1 shamp C*20 shamp Dye 1 Lock 1 55.22 59.34 Lock 3 47.84 46.85 Dye 2 Lock 2 37.13 33.54 Lock 4 36.65 31.09 Dye 3 Lock 1 49.58 48.87 Lock 3 49.84 51.37

[0783] It appears that the colour obtained with the dyeing process is very chromatic compared with the result for chromaticity of the fibre before treatment. In addition, it appears that the chromaticity remains very intense even after 20 shampooing operations for the various dyes of the invention.

[0784] e) Composition Examples

TABLE-US-00003 Composition Formula Composition Thiol- Formula Composition comprising Thiol- Formula Non- reducing comprising thiol-comprising agent 8% at reducing agent reducing agent Dye Active agent pH 3.5 1% at pH 3.5 5% at pH 3.5 composition Water 89.0 98.36 94.75 95.5 Pure thiolactic 8.0 1.0 X X acid (Aldrich) 2-Amino-2- 3.0 0.64 X X methyl-1- propanol Para- X X 5.0 X hydroxyphenol (Aldrich) 0.1N HCl 0.25 (Aldrich) Dye X X X 0.5

Example 2

[0785] Preparation of the Compositions

Composition A1:

[0786] Solution of thiolactic acid at 1% by weight at pH 3.5.

[0787] In a 150 ml flask 1 gram of thiolactic acid was added, then 50 grams of water was added and then 2-amino-2-methyl-1-propanol was added until a pH of the solution at 3.5 was obtained. It was then supplemented with water up to 100 grams and the final pH was checked (3.52).

Composition A2:

[0788] Solution of thiolactic acid at 1% by weight at pH 8.3.

[0789] In a 150 ml flask 1 gram of thiolactic acid was added, then 50 grams of water was added and then 2-amino-2-methyl-1-propanol was added until a pH of the solution at 8.3 was obtained. It was then supplemented with water up to 100 grams and the final pH was checked (8.32).

Composition B1:

[0790] Acid Red 18 dye solution at 0.5% by weight at spontaneous pH (pH=9.6)

[0791] Acid Red 18 dye of formula:

##STR00028##

[0792] In a 150 ml flask was introduced 0.5 gram of Acid red 18 dye and then 99.5 grams of water was added. The spontaneous pH was then measured after complete dissolution of the dye (spontaneous pH=9.62).

Composition C1:

[0793] para-hydroxyphenol solution at 5% by weight at pH 3.5.

[0794] In a 150 ml flask was introduced 5 grams of para-hydroxyphenol and then 50 grams of water was added. It was then added, dropwise, a solution of 1N hydrochloric acid until a pH of the solution at 3.5. It was then supplemented with water up to 100 grams and the final pH was checked (3.51).

[0795] Protocols

[0796] The following treatments were performed on 90% white natural hair locks.

Treatment 1:

[0797] A 1 gram lock is placed flat on a sheet of aluminum foil on a lock plate at 27 C. 2 grams of composition A1 were gently deposited along the lock and then applied with a coloring brush so as to have a homogeneous treatment. It was then left for 30 minutes and then wrung with KIMTECH paper. 2 grams of composition B1 was then deposited along the lock and then applied with a coloring brush to have a homogeneous treatment. It was then left for 20 minutes and then wrung with KIMTECH paper. 2 grams of composition C1 were then deposited along the lock and then applied with a coloring brush in order to have a homogeneous treatment. It was then left for 20 minutes and then wrung with KIMTECH paper. A blow-dry was then carried out at 80 C. (10 passes) and a hair straightening with straightening iron was carried out at 230 C. (10 passes in 6 seconds). A shampoo was then performed.

Treatment 2:

[0798] A 1 gram lock is placed flat on a sheet of aluminum foil on a lock plate at 27 C. 2 grams of composition A1 were gently deposited along the lock and then applied with a coloring brush so as to have a homogeneous treatment. It was then left for 30 minutes and then wrung with KIMTECH paper. 2 grams of composition C1 was then deposited along the lock and then applied with a coloring brush to have a homogeneous treatment. It was then left for 20 minutes and then wrung with KIMTECH paper. 2 grams of composition B1 were then deposited along the lock and then applied with a coloring brush in order to have a homogeneous treatment. It was then left for 20 minutes and then wrung with KIMTECH paper. A blow-dry was then carried out at 80 C. (10 passes) and a hair straightening with straightening iron was carried out at 230 C. (10 passes in 6 seconds). A shampoo was then performed.

Treatment 3:

[0799] A 1 gram lock is placed flat on a sheet of aluminum foil on a lock plate at 27 C. 2 grams of composition A2 were gently deposited along the lock and then applied with a coloring brush so as to have a homogeneous treatment. It was then left for 30 minutes and then wrung with KIMTECH paper. 2 grams of composition B1 was then deposited along the lock and then applied with a coloring brush to have a homogeneous treatment. It was then left for 20 minutes and then wrung with KIMTECH paper. 2 grams of composition C1 were then deposited along the lock and then applied with a coloring brush in order to have a homogeneous treatment. It was then left for 20 minutes and then wrung with KIMTECH paper. A blow-dry was then carried out at 80 C. (10 passes) and a hair straightening with straightening iron was carried out at 230 C. (10 passes in 6 seconds). A shampoo was then performed.

Treatment 4:

[0800] A 1 gram lock is placed flat on a sheet of aluminum foil on a lock plate at 27 C. 2 grams of composition A2 were gently deposited along the lock and then applied with a coloring brush so as to have a homogeneous treatment. It was then left for 30 minutes and then wrung with KIMTECH paper. 2 grams of composition C1 was then deposited along the lock and then applied with a coloring brush to have a homogeneous treatment. It was then left for 20 minutes and then wrung with KIMTECH paper. 2 grams of composition B1 were then deposited along the lock and then applied with a coloring brush in order to have a homogeneous treatment. It was then left for 20 minutes and then wrung with KIMTECH paper. A blow-dry was then carried out at 80 C. (10 passes) and a hair straightening with straightening iron was carried out at 230 C. (10 passes in 6 seconds). A shampoo was then performed.

[0801] The locks were then studied in a spectrophotometer to determine the color build-up E*, representing the color uptake between the treated lock and the untreated lock (color build-up or color uptake), and the chromaticity C * (chromaticity).

[0802] The colour of the locks was evaluated in the CIE L* a* b* system using a Minolta Spectrophotometer CM3610D colorimeter. In this L* a* b* system, the three parameters respectively denote the intensity of the colour (L*), the green/red colour axis (a*) and the blue/yellow colour axis (b*).

[0803] The lower the value of L*, the darker or more intense the color. The higher the value of a*, the redder the shade; the higher the value of b*, the yellower the shade.

[0804] Color Build-Up:

[0805] The variation in colouration between the non-dyed and dyed locks of hair is defined by (E*) according to the following equation:

E*={square root over ((L*L.sub.o*).sub.2+(a*a.sub.o*).sup.2+(b*b.sub.o*).sup.2)}

[0806] In this equation, L*, a* and b* represent the values measured on locks of hair after dyeing and L.sub.0*, a.sub.0* and b.sub.0* represent the values measured on locks of hair before dyeing. The higher the value of E*, the greater the colour build-up.

[0807] Chromaticity:

[0808] The chromaticity is calculated from the measurements of a* and of b* according to the following formula:

C*={square root over (a*.sup.2+b*.sup.2)}

[0809] The higher the value of C*, the more chromatic is the colour.

[0810] The results are summarized in the table below:

TABLE-US-00004 Treatments L* a* b* C* E* 1 (Invention) 45.93 19.29 12.64 23.06 21.02 2 (Invention) 50.01 19.87 12.53 23.25 19.57 3 (Comparative) 51.91 12.9 12.86 18.2 12.7 4 (Comparative) 52.03 11.38 12.38 16.8 11.62

[0811] It appears from the above tests that the color build-up, the intensity and the chromaticity of the colorations obtained according to the process of the invention (treatments 1 and 2 with a composition A1 at pH=3.52), whatever the order of application of the dye and para-hydroxyphenol, are significantly better than the colorations obtained according to the comparative process (treatments 3 and 4 with a composition A2 at pH=8.32).