AZO DERIVATIVES CONTAINING A PYRAZOLINONE UNIT FOR DYEING KERATIN FIBRES

摘要

The subject of the present invention is azo derivatives containing a pyrazolinone unit having the following formula (I), their mesomeric forms, their addition salts with an acid and their solvates and their use for dyeing keratin fibres. The subject of the invention is also a composition for dying keratin fibres comprising at least one azo derivative containing a pyrazolinone unit of formula (I) as direct dye, and the method for dyeing keratin fibres using this composition. The present invention makes it possible in particular to obtain chromatic colours that are resistant to the various attacks to which the hair may be subjected, in particular to shampoos and to light.