Hair dye composition comprising an azo dye containing a dissociative proton, method and use

摘要

A hair dyeing composition comprises a specific dissociative azo dye free from anionic sulfo or carboxyl group and quaternary ammonium group. A hair dyeing composition comprises a dissociative azo dye of formula A-N=N-B. A : optionally substituted phenyl or naphthyl group, and does not contains sulfo or carboxyl groups or quaternary ammonium group; and B : aromatic group required for azo dye to form a dissociative azo dye which is free from anionic sulfo or carboxyl group and quaternary ammonium group. Independent claims are also included for the following: (1) dyeing of human or animal hair which involves applying the composition containing azo dye on hair, rinsing hair after dyeing and drying; and (2) use of azo dye for dyeing human or animal hair.