Composition for dyeing keratinous fibres comprising a direct dye having a disulphide/thiol functional group, a thickening polymer, an ethoxylated fatty alcohol and/or a nonionic surfactant, an alkaline agent and a reducing agent

Abstract

A subject-matter of the invention is a method for dyeing and/or lightening keratinous fibres, such as the hair, employing i) at least one direct dye having a disulphide, thiol or protected thiol functional group and ii) at least one thickening organic polymer, iii) at least one (poly)ethoxylated fatty alcohol and/or one nonionic surfactant, iv) at least one alkaline agent and v) at least one reducing agent. Another subject-matter of the invention is a composition comprising the ingredients i) to v), the use of the combination of i), ii), iii), iv) and v) for dyeing and/or lightening keratinous fibres and a multicompartment kit comprising the ingredients i) to v). The dyeing method and the composition according to the invention make it possible in particular to obtain a lasting coloration on keratinous fibres which is intense, chromatic and/or homogeneous, with or without the use of an oxidizing agent.