| abstract |
Process for dyeing human keratinous fibres, consisting in applying on these fibres at least least one composition (A) containing, in a cosmetically acceptable medium, one or more indole derivatives corresponding to the formula (I) <IMAGE> (I) in which: R1 denotes a hydrogen atom, a lower C1-C6 lower akly group or a group -SiR9R10R11; R2 and R3, which may be identical or different, denote a hydrogen atom, a C1-C6 lower alkyl group, a carboxyl group, a lower alkoxycarbonyl group wherein the alkoxy moiety contains 1 to 6 carbon atoms, or a group -COOSiR9R10R11; R4 and R5, which may be identical or different, denote a hydrogen atom, a C1-C20 linear or branched alkyl group, a formyl group, a linear or branched C2-C20 acyl group, a linear or branched C3-C20 alkenoyl group, a group -SiR9R10R11, a group -P(O) (OR6)2 or a group R6OSO2-, or alternatively R4 and R5, together with the oxygen atoms to which they are attached, form a ring optionally containing a carbonyl group, a methylene group, a thiocarbonyl group or one of the following groups; >P(O)OR6, or >CR7R8; R6 and R7 denoting a hydrogen atom or C1-C6 lower alkyl group, R8 denoting a C1-C6 lower alkoxy group or a mono- or di-C1-C6 alkylamino group, R9,R10 and R11, which may be identical or different, denoting C1-C6 linear or branched alkyl groups, and the corresponding salts of alkali metals, alkaline-earth metals and amines, at least one of the radicals R1 to R5 being other than hydrogen, in combinations: either (a) with iodide ions, or (b) with a solution of hydrogen peroxide at a pH of between 3.5 and 7, the application of the composition (A) being preceded or followed by the application of composition (B) which contains, in a cosmetically acceptable medium, either (a) hydrogen peroxide at a pH of between 2 and 7 when the composition (A) contains iodide ions, or (b) iodide ions when the composition (A) contains hydrogen peroxide. |