| abstract |
Hybrid dyes of structure (I), X-S-Y (I) in which X and Y are each derived from various oxidation dye precursors of the developer type and S is a direct bond or at least one spacer group, are especially suitable for colouring keratin fibres, in particular, human hair. By the use of colouring agents with the above dyes, a series of problems which occurs with the use of complex dye mixtures, can be avoided or significantly reduced. |