Patent ID: 7407516
Filing Date: 2008-08-05
Classification: C09B

Abstract:
1. A method of dyeing human keratin fibers, comprising applying to the keratin fibers a composition comprising: a cosmetic medium suitable for dyeing human keratin fibers, wherein said medium is water or a mixture of water and at least one organic solvent suitable for dyeing human keratin fibers, and at least one dicationic diazo dye of formula (I), comprised in said medium: wherein: p=0 or 1, W W W W wherein in formulae (II), (III), (IV) and (V): X X X X Z Z Z the bond a of the 5-membered cationic ring of formula (II) is linked to the azo group of formula (I), the bond b of the 6-membered cationic ring of formula (III) is linked to the azo group of formula (I), wherein when p=0, then L is chosen from linear and branched C wherein when p=1, then L is chosen from saturated and unsaturated, linear and branched C R R R X is chosen from organic and mineral anions.