Method of dyeing keratin-containing fibres

摘要

A method of dyeing keratin-containing fibres, which comprises using a dye of formula wherein R₁ and R₂ are each independently of the other hydrogen, C₁-C₄alkyl, halogen or nitro, R₃ and R₄ are each independently of the other unsubstituted C₁-C₄alkyl or C₁-C₄alkyl substituted by OH, C₁-C₄alkoxy, halogen, CN or by phenyl, X₁ and X₂ are each independently of the other hydrogen, C₁-C₄alkyl, C₁-C₄alkoxy or halogen, R₅ is hydrogen or C₁-C₄alkyl, R₆ is C₅-C₁₂alkyl or C₅-C₈cycloalkyl each unsubstituted or substituted by OH, C₁-C₄alkoxy, halogen, CN or phenyl, or R₆ is C₁-C₄alkyl substituted by phenyl or by C₅-C₈cycloalkyl, or wherein R₅ and R₆ together with the nitrogen atom linking them form a piperazine ring, which is substituted, at the nitrogen atom that is not bonded to the phenyl group, by C₁-C⁸-alkyl or phenyl, or which is quaternised at that nitrogen atom by two such groups, the C₁-C₈-alkyl radicals and phenyl mentioned as substituents of the nitrogen atom of the piperazine ring being unsubstituted or substituted by OH, C₁-C₄alkoxy, halogen, CN or phenyl, and wherein X^- is an anion.