Patent ID: 7393366

Claim:
An agent for the nonoxidative coloring of keratin fibers, comprising at least one zwitterionic azo dye of the general formula (I); wherein R1 is an alkyl sulfonate radical of the formula (II); R2 is hydrogen or a hydroxyl group; m is 0 to (n−1); p is 0 to (n−1) where m+p=(n−1); n is an integer from 1 to 6; X is oxygen, sulfur, N—R3 or C—R4; Y is C—R5, nitrogen, N—R6, sulfur or oxygen; Z is C—R7 or nitrogen; and wherein the heterocycle of the formula (I) comprises at least two and at most three heteroatoms, where the heterocycle has at most one sulfur atom or oxygen atom; R3 and R6 may be identical or different and, independently of one another, are a saturated or unsaturated (C 1 -C 12 )-alkyl group, a (C 1 -C 12 )-alkyl group substituted by a halogen atom, a hydroxy-(C 2 -C 12 )-alkyl group, an amino-(C 1 -C 12 )-alkyl group, a substituted or unsubstituted phenyl group or a substituted or unsubstituted benzyl group; R4, R5 and R7 may be identical or different and, independently of one another, are hydrogen, a halogen atom, a saturated or unsaturated (C 1 -C 12 )-alkyl group, a (C 1 -C 12 )-alkyl group substituted by a halogen atom (F, Cl, Br, I), a hydroxyl group, a hydroxy-(C 1 -C 12 )-alkyl group, a (C 1 -C 12 )-alkoxy group, a cyano group, a nitro group, an amino group, a (C 1 -C 12 )-alkylamino group, a (C 1 -C 12 )-dialkylamino group, a carboxylic acid group, a C(O)O—(C 1 -C 12 )-alkyl group, a substituted or unsubstituted C(O)O-phenyl group, a substituted or unsubstituted phenyl group or a naphthyl group, or a substituted or unsubstituted heteroaryl group; or if Y and Z are C—R5 and C—R7, the radical groups R5 and R7, together with the remaining molecule, can form a heterocyclic or carbocyclic, saturated or unsaturated, substituted or unsubstituted ring system; or if X and Y are C—R4 and C—R5, the radical groups R4 and R5, together with the remaining molecule, can form a heterocyclic or carbocyclic, saturated or unsaturated, substituted or unsubstituted ring system; K is a radical group of the aniline or phenol series or a monocyclic or polycyclic heterocyclic radical group.