Dyeing composition for dyeing keratinous fibres comprising a cationic azo-dye

A composition for dyeing keratinous fibers, and in particular human keratinous fibers such as the hair, comprising at least one cationic azo dye of the following formula (I):

• W1—N═N—W2—W3
• in which
• W1 represents a 5-membered cationic aromatic heterocycle of the following formula (II)
• 16
• formula (II)
• W2 represents a divalent carbonaceous aromatic or pyridine group of the following formulae (III) or (IV)
• 17
• W3 represents a 7- or 8-membered heterocycle of the following formula (V)
• 18
• in which formulae
• Z1 represents an oxygen or sulfur atom or a radical NR12,
• Z2 represents a nitrogen atom or a radical CR11,
• R12 and R13 represent, independently of one another, a C1-C8 alkyl radical optionally substituted by one or more radicals chosen from a hydroxyl, a C1-C2 alkoxy, a C2-C4 (poly)hydroxyalkoxy radical, an amino, a C1-C2 (di)alkylamino, a carboxyl or a sulfonic;
• an optionally substituted phenyl radical,
• R10 and R11 represent, independently of one another, a hydrogen atom;
• a C1-C4 alkyl radical, optionally substituted by one or more radicals chosen from a hydroxyl, a C1-C2 alkoxy, a C2-C4 (poly)hydroxyalkoxy radical, an amino, a C1-C2 (di)alkylamino, a carboxyl or a sulfonic;
• an optionally substituted phenyl radical;
• a carboxyl radical;
• a sulfonylamino radical;
• R6, R7, R8 and R9 represent, independently of one another, a hydrogen atom;
• a chlorine atom;
• a bromine atom;
• a linear or branched C1-C6 hydrocarbonaceous chain which can form one or more 3- to 6-membered carbonaceous rings and which can be saturated or unsaturated, of which one or more carbon atoms of the carbonaceous chain can be replaced by an oxygen, nitrogen or sulfur atom or by an SO2 group, and the carbon atoms of which can be, independently of one another, substituted by one or more halogen atoms;
• R6, R7, R8 and R9 not comprising a peroxide bond or diazo or nitroso radicals,
• n is an integer equal to 1 or 2,
• Z4 represents an oxygen or sulfur atom, a radical NR2 or a radical CR2R2′,
• R0, R1, R2, R2′, R3, R4 and R5 represent, independently of one another, a hydrogen atom;
• an alkyl radical;
• an alkoxy radical;
• a hydroxyl radical;
• amino;
• acetoxy;
• a group —NR14R15, R14 and R15 representing, independently of one another, a hydrogen atom, a C1-C4 alkyl radical substituted by one or more radicals chosen from a halogen atom, a hydroxyl, C1-C2 alkoxy, amino or C1-C2 amino(di)alkyl radical;
• a sulfonylamino radical;
• a carboxyl radical;
• a carboxamido radical;
• an amido radical;
• a mono- or dialkylamido radical;
• a halogen;
• a C1-C6 alkyl radical substituted by one or more radicals chosen from a hydroxyl, C1-C2 alkoxy, C2-C4 (poly)hydroxyalkoxy, amino and C1-C2 (di)alkylamino radical,
• X is an organic or inorganic anion.