摘要：

A two-stage process for dyeing keratin fibres, especially human hair, which comprises applying a first composition containing at least one mercaptan present in a concentration insufficient to causes degradation of the hair and subsequently without intermediate rinsing, applying an oxidising composition so as to develop the dyestuff, and optionally one or more couplers, which is applied to the fibres, the dyestuff being an oxidative dyestuff precursor of the para type, a diphenylamine, a polyhydroxybenzene, a polyhydroxynaphthalene, a polyaminobenzene, a polyaminophenol or a polyaminopolyhydroxybenzene is described and compositions for use therein.

展开