Abstract:
A subject-matter of the invention is a) a method for dyeing keratinous substances starting from a dyeing agent chosen from coloured oligomers and polymers obtained from the polycondensation of i) meta-phenylenediamine (MPD) couplers in the presence of ii) one or more ingredients chosen from radical initiators and/or chemical oxidizing agents, b) a composition comprising one or more coloured oligomers and/or one or more coloured polymers as defined above and c) a coloured oligomeric or polymeric dyeing agent obtained by reaction between i) and ii) as defined above, and the use of the coloured oligomer(s) or polymer(s) for dyeing keratinous substances. The dyeing method and the composition according to the invention make it possible in particular to obtain a long-lasting colouration on keratinous fibres which is vivid, chromatic and/or homogeneous.
Abstract:
The present invention relates to azomethine-type direct dyes having a triaromatic unit of formula (I) below: and also the use thereof for dyeing keratin fibres, in particular human keratin fibres such as the hair. The invention also relates to a composition for dyeing keratin fibres, comprising, in a medium suitable for dyeing, such direct dyes. Another subject of the present invention is a method for dyeing keratin fibres using said dye composition. Finally, the present invention also relates to precursors of these direct dyes.