A process for dyeing keratin materials, comprising applying to keratin materials a dye composition in a cosmetically acceptable medium, wherein the dye comprises a fluorescent dye of formula (I) or (II):
- the organic or mineral acid salts thereof, optical isomers and geometric isomers thereof, and the solvates thereof:
- wherein in formulae (I) and (II):
- n is an integer ranging from 1 to 2;
- m is an integer ranging from 0 to 1;
- Ra and Rb, which may be identical or different, are chosen from a hydrogen atom and a C1-C4 alkyl group;
- R1 is chosen from a hydrogen atom and a (C1-C6)alkyl group, optionally substituted with a group chosen from halogen, C1-C4 alkoxy, C1-C4 (di)(alkyl)amino, phenyl, tolyl, and methoxyphenyl;
- or else R1 and Ra together form a (C3-C6)alkylene chain or a (C3-C7)alkenylene;
- R2 and R3, which may be identical or different, are chosen from a hydrogen atom and a halogen atom, an optionally substituted (C1-C6)alkyl group, a (C1-C6)alkoxy group, or a (C1-C6)alkylthio group;
- or else R2 and R3 form, together with the carbon atoms which bear them, an optionally substituted benzo ring;
- R4, R5 and R6, which may be identical or different, are chosen from:
- a hydrogen atom;
- a C1-C6 alkyl radical optionally substituted with at least one radical chosen from the radicals hydroxyl, C1-C2 alkoxy, C2-C4 (poly)hydroxyalkoxy, acylamino, and amino substituted with two C1-C4 alkyl radicals, which may be identical or different;
- a halogen atom such as chlorine, fluorine or bromine;
- a hydroxyl group;
- a C1-C2 alkoxy radical;
- a C1-C2 alkylthio radical;
- an amino radical;
- a 5- or 6-membered heterocycloalkyl radical which may be substituted with 1 to 3 groups, which may be identical or different, chosen from hydroxyl, amino, (di)alkylamino, and C1-C4 hydroxyalkyl;
- an amino radical substituted with one or two C1-C6 alkyl radicals, which may be identical or different, optionally bearing at least:
- i) a hydroxyl group,
- ii) an amino group optionally substituted with one or two C1-C3 alkyl radicals, it being possible for said alkyl radicals to form, with the nitrogen atom to which they are attached, a saturated or unsaturated, optionally substituted heterocycle comprising from 5 to 7 members, optionally comprising at least one other heteroatom which may or may not be different from nitrogen,
- —N(R)—C(O)—R′ wherein the R radical is chosen from a hydrogen atom and a C1-C4 alkyl radical optionally bearing at least one hydroxyl group, and the R′ radical is a C1-C2 alkyl radical;
- a carboxylic radical in acid or salified form;
- a polyhaloalkyl group comprising from 1 to 6 carbon atoms and from 1 to 6 halogen atoms, which may be identical or different;
- or else two contiguous radicals R4 with R5 and/or R5 with R6 form, together with the carbon atoms which bear them, a benzo ring or a heterocycle, optionally substituted, fused to the phenyl group;
- or else R4, R5 and R6 form, together with the phenyl group of formula (II), a tricyclic unit of julolidine type:
- wherein Rc and Rd are chosen from a hydrogen atom and a C1-C4 alkyl group;
- L is a C1-C20 divalent hydrocarbon-based chain, which is optionally substituted, optionally interrupted and/or optionally terminated at one or the other of its ends i) with at least one divalent group or combinations thereof chosen from:
- —N(R)—;
- —N+(R)(Ro)—, An−, —O—, —S—, —CO—, and —SO2— with R and Ro, which may be identical or different, chosen from a hydrogen, and a C1-C4 alkyl, hydroxyalkyl or aminoalkyl radical, and An− is an anionic counterion, or ii) with a cationic heterocycle or cationic heteroaryl Het+, An−, wherein An− is defined as above and Het+ is a saturated or unsaturated heterocycle comprising from 5 to 10 members, or a heteroaryl comprising from 5 to 10 members;
- X is chosen from an oxygen atom, a sulfur atom and an NR group wherein R is chosen from a hydrogen atom and a (C1-C6)alkyl group;
- Y is chosen from:
- i) a hydrogen atom;
- ii) an alkali metal;
- iii) an alkaline earth metal;
- iv) an ammonium group:
- N+RαRβRγRδ, An″− or a phosphonium group:
- P+RαRβRγRδ, An″− with Rα, Rβ, Rγ and Rδ, which may be identical or different, chosen from a hydrogen atom and a (C1-C4)alkyl group and An″− is an anionic counterion;
- or v) a thiol-function-protecting group;
- W is chosen from an oxygen atom, sulfur atom, and an NR′ group wherein R′ is chosen from a hydrogen atom and a (C1-C4)alkyl group;
- and
- Q− is an anionic counterion;
- it being understood that, when n is 2, then m is zero, and when n is 1, then m is 1.