| abstract |
The invention provides compositions and methods for the direct dyeing of keratinous fibers, with particular regard to human hair on the head. The compositions of the invention contain novel anthraquinone mixtures in which each of the component anthraquinones has similar polarities. Compared with the known, commercially-available anthraquinone hair dye colorant, Disperse Blue 3 (DB 3), which comprises a mixture of anthraquinones having dissimilar polarities, the anthraquinone mixtures of the present invention surprisingly and advantageously were found to color hair more intensely and also to synergize to a greater extent with other anthraquinones, such as Disperse Violet 1 (DV 1), when used in hair dye formulations. The novel compound 1-[(2-hydroxyethyl)amino]-4-[(2-hydroxypropyl)amino]-9,10-anthracenedione is also disclosed. |