摘要 |
The invention relates to the dyeing of human keratinous fibres, in particular the hair, using anionic direct dyes or acid dyes having a tetraalkylammonium counterion of formula (I), with Col(-)m, R1, R2, R3, R4, m, and n as defined in the description. A subject-matter of the invention is a dyeing composition comprising an anionic dye of formula (I) and a method for dyeing keratinous fibres, such as the hair, employing the said composition. A subject-matter of the invention is likewise novel dyes of formula (I) and their uses for the colouring of keratinous fibres. This composition makes it possible to obtain a chromatic, powerful and particularly persistent colouring on keratinous fibres. |