IP Library › Granted Patent US 7,513,918

Granted Patent B2

US 7,513,918 · App. 11/788,065 · Granted Apr 7, 2009

Agents for coloring keratin fibers comprising zwitterionic azomethine dyes

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Quick Facts

Patent No.: US 7,513,918
App. No.: 11/788,065
Granted: Apr 7, 2009
Kind: B2

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Abstract

The present invention relates to agents for coloring keratin fibers which comprise at least one zwitterionic azomethine dye of the general formula (I), (II), or (III) in which z is a heterocycle of the formula in which R8 is an alkyl sulfonate radical of the formula (XIII);

Claims (412)

1. An agent for the nonoxidative coloring of keratin fibers, comprising at least one zwitterionic azomethine dye of the general formula (I), (II), or (III)

wherein

R1 and R2 may be identical or different and independently of one another, are selected from the group consisting of 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, 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 C(O)O-phenyl group, an unsubstituted C(O)O-phenyl group, a substituted phenyl group, an unsubstituted phenyl group, a substituted naphthyl group, an unsubstituted naphthyl group, a substituted heteroaryl group and an unsubstituted heteroaryl group;

R3 is selected from the group consisting of hydrogen, a saturated or unsaturated (C 1 -C 12 )-alkyl group and a hydroxy-(C 2 -C 12 )alkyl group, or forms with a carbon atom of the benzene ring a five or six-membered heterocycle which may be substituted with one or more C 1 -C 12 )-alkyl groups;

R4 is selected from the group consisting of hydrogen, a saturated or unsaturated (C 1 -C 12 )-alkyl group, a substituted phenyl group and an unsubstituted phenyl group;

R5 is selected from the group consisting of the general formula (XIV), (XV), and (XVI)

R6 and R7 may be identical or different and, independently of one another, are selected from the group consisting of hydrogen, a halogen atom, an amino group, a (C 1 -C 12 )-alkylamino group, a (C 1 -C 12 )-dialkylamino group, a C 1 -C 6 -alkylcyano group, a hydroxyl group, a nitro group, a saturated or unsaturated (C 1 -C 12 )-alkyl group, a hydroxy-(C 1 -C 12 )-alkyl group, a (C 1 -C 12 )-alkoxy group, a methoxy-(C 1 -C 12 )-alkyl group and a C(O)O—(C 1 -C 12 )-alkyl group;

z is selected from the group consisting of heterocycles according to formula (IV) to (XII)

X is oxygen or sulfur;

R8 is an alkyl sulfonate radical of the formula (XIII);

R9 is selected from the group consisting of 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, a hydroxyl group, a hydroxy-(C 2 -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, and a benzene ring condensed to the heteroaromatic ring of formula (IV) to (XII);

R10 is selected from the group consisting of a saturated or unsaturated (C 1 -C 12 )-alkyl group or a saturated or unsaturated hydroxy-(C 1 -C 12 )-alkyl group;

R11 and R12 may be identical or different and independently of one another, are a saturated or unsaturated (C 1 -C 12 )-alkyl group;

R13 is hydrogen or a hydroxyl group;

R14, R15, R16, and R17 may be identical or different and independently of one another, are selected from the group consisting of 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, 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 C(O)O-phenyl group, an unsubstituted C(O)O-phenyl group, a substituted phenyl group and an unsubstituted phenyl group,

m is in a range of 0 to (n−1);

p is in a range of 0 to (n−1) with m+p=(n−1) and

n is an integer from 1 to 6; and further comprising at least one polymer which is selected from the group consisting of natural polymers customary for cosmetic agents, synthetic polymers and modified polymers of natural origin, and being in the form of a color setting composition.

2. An agent for the simultaneous lightening and coloring of keratin fibers, comprising at least one zwitterionic azomethine dye of the general formula (I), (II), or (III)

wherein

R1 and R2 may be identical or different and independently of one another, are selected from the group consisting of 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, 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 C(O)O-phenyl group, an unsubstituted C(O)O-phenyl group, a substituted phenyl group, an unsubstituted phenyl group, a substituted naphthyl group, an unsubstituted naphthyl group, a substituted heteroaryl group and an unsubstituted heteroaryl group;

R3 is selected from the group consisting of hydrogen, a saturated or unsaturated (C 1 -C 12 )-alkyl group, and a hydroxy-(C 2 -C 12 )alkyl group, or forms with a carbon atom of the benzene ring a five or six-membered heterocycle which may be substituted with one or more (C 1 -C 12 )-alkyl group;

R4 is selected from the group consisting of hydrogen, a saturated or unsaturated (C 1 -C 12 )-alkyl group, a substituted phenyl group and an unsubstituted phenyl group;

R5 is selected from the group consisting of the general formula (XIV), (XV), and (XVI)

R6 and R7 may be identical or different and, independently of one another, are selected from the group consisting of hydrogen, a halogen atom, an amino group, a alkylamino group, a (C 1 -C 12 )-dialkylamino group, a C 1 -C 6 -alkylcyano group, a hydroxyl group, a nitro group, a saturated or unsaturated (C 1 -C 12 )-alkyl group, a hydroxy-(C 1 -C 12 )-alkyl group, a (C 1 -C 12 )-alkoxy group, a methoxy-(C 1 -C 12 )-alkyl group and a C(O)O—(C 1 -C 12 )-alkyl group;

z is selected from the group consisting of heterocycles of the formula (IV) to (XII)

X is oxygen or sulfur;

R8 is an alkyl sulfonate radical of the formula (XIII);

R9 is selected from the group consisting of 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, a hydroxyl group, a hydroxy-(C 2 -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, and a benzene ring condensed to the heteroaromatic ring of formula (IV) to (XII);

R10 is selected from the group consisting of a saturated or unsaturated (C 1 -C 12 )-alkyl group and a saturated or unsaturated hydroxy-(C 1 -C 12 )-alkyl group;

R11 and R12 may be identical or different and independently of one another, are a saturated or unsaturated (C 1 -C 12 )-alkyl group;

R13 is hydrogen or a hydroxyl group;

m is in a range of 0 to (n−1);

p is in a range of 0 to (n−1) with m+p=(n−1) and

n is an integer from 1 to 6; and further comprising an oxidizing agent, wherein the oxidizing agent is selected from the group consisting of hydrogen peroxide and its addition compounds urea, melamine, sodium borate or sodium carbonate.

3. An oxidative colorant for coloring fibers based on at least one oxidation dye precursor, comprising at least one zwitterionic azomethine dye of the general formula (I), (II), or (III)

wherein

R1 and R2 may be identical or different and independently of one another, are selected from the group consisting of 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, 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 C(O)O-phenyl group, an unsubstituted C(O)O-phenyl group, a substituted phenyl group, an unsubstituted phenyl group, a substituted naphthyl group, an unsubstituted naphthyl group, a substituted heteroaryl group and an unsubstituted heteroaryl group;

R4 is selected from the group consisting of hydrogen, a saturated or unsaturated (C 1 -C 12 )-alkyl group, a substituted phenyl group and an unsubstituted phenyl group;

R5 is selected from the group consisting of the general formula (XIV), (XV) and (XVI)

z is selected from the group consisting of heterocycles of the formula (IV) to (XII)

X is oxygen or sulfur;

R8 is an alkyl sulfonate radical of the formula (XIII);

R9 is selected from the group consisting of 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, a hydroxyl group, a hydroxy-(C 2 -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, and a benzene ring condensed to the heteroaromatic ring of formula (IV) to (XII);

R10 is selected from the group consisting of a saturated or unsaturated (C 1 -C 12 )-alkyl group and a saturated or unsaturated hydroxy-(C 1 -C 12 )-alkyl group;

R11 and R12 may be identical or different and independently of one another, are a saturated or unsaturated (C 1 -C 12 )-alkyl group;

R13 is hydrogen or a hydroxyl group;

R14, R15, R16, and R17 may be identical or different and independently of one another, are selected from the group consisting of 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, 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 C(O)O-phenyl group, an unsubstituted C(O)O-phenyl group, a substituted phenyl group and an unsubstituted phenyl group,

m is in a range of 0 to (n−1);

p is in a range of 0 to (n−1) with m+p=(n−1) and

4. The agent according to claim 1 , wherein in the formula (I), (II), and (III) R13 is hydrogen and n is 2 or 3.

5. The agent according to claim 1 , wherein the zwitterionic azomethine dye of the formula (I), (II), or (III) is selected from the group consisting of 4-(4-{[methyl(phenyl)hydrazono]methyl}-1-pyridiniumyl)-1-butanesulfonate,

4-(3-{[methyl(phenyl)hydrazono]methyl}-1-pyridiniumyl)-1-butanesulfonate,

4-(2-{[methyl(phenyl)hydrazono]methyl}-1-pyridiniumyl)-1-butanesulfonate,

4-(4-{[(4-methoxyphenyl)(methyl)hydrazono]methyl}-1-pyridiniumyl)-1-butanesulfonate,

4-(3-{[(4-methoxyphenyl)(methyl)hydrazono]methyl}-1-pyridiniumyl)-1-butanesulfonate,

4-(2-{[(4-methoxyphenyl)(methyl)hydrazono]methyl}-1-pyridiniumyl)-1-butanesulfonate,

4-(4-{[(2-methoxyphenyl)(methyl)hydrazono]methyl}-1-pyridiniumyl)-1-butanesulfonate,

4-(3-{[(2-methoxyphenyl)(methyl)hydrazono]methyl}-1-pyridiniumyl)-1-butanesulfonate,

4-(2-{[(2-methoxyphenyl)(methyl)hydrazono]methyl}-1-pyridiniumyl)-1-butanesulfonate,

4-(4-{[(4-hydroxyphenyl)(methyl)hydrazono]methyl}-1-pyridiniumyl)-1-butanesulfonate,

4-(3-{[(4-hydroxyphenyl)(methyl)hydrazono]methyl}-1-pyridiniumyl)-1-butanesulfonate,

4-(2-{[(4-hydroxyphenyl)(methyl)hydrazono]methyl}-1-pyridiniumyl)-1-butanesulfonate,

4-(4-{[methyl(4-methylphenyl)hydrazono]methyl}-1-pyridiniumyl)-1-butanesulfonate,

4-(3-{[methyl(4-methylphenyl)hydrazono]methyl}-1-pyridiniumyl)-1-butanesulfonate,

4-(2-{[methyl(4-methylphenyl)hydrazono]methyl}-1-pyridiniumyl)-1-butanesulfonate,

4-(4-{[(4-chlorophenyl)(methyl)hydrazono]methyl}-1-pyridiniumyl)-1-butanesulfonate,

4-(3-{[(4-chlorophenyl)(methyl)hydrazono]methyl}-1-pyridiniumyl)-1-butanesulfonate,

4-(2-{[(4-chlorophenyl)(methyl)hydrazono]methyl}-1-pyridiniumyl)-1-butanesulfonate,

4-(4-{[methyl(4-nitrophenyl)hydrazono]methyl}-1-pyridiniumyl)-1-butanesulfonate,

4-(3-{[methyl(4-nitrophenyl)hydrazono]methyl}-1-pyridiniumyl)-1-butanesulfonate,

4-(2-{[methyl(4-nitrophenyl)hydrazono]methyl}-1-pyridiniumyl)-1-butanesulfonate,

4-{4-[(phenylhydrazono)methyl]-1-pyridiniumyl}-1-butanesulfonate,

4-{3-[(phenylhydrazono)methyl]-1-pyridiniumyl}-1-butanesulfonate,

4-{2-[(phenylhydrazono)methyl]-1-pyridiniumyl}-1-butanesulfonate,

4-(4-{[(4-methoxyphenyl)hydrazono]methyl}-1-pyridiniumyl)-1-butanesulfonate,

4-(3-{[(4-methoxyphenyl)hydrazono]methyl}-1-pyridiniumyl)-1-butanesulfonate,

4-(2-{[(4-methoxyphenyl)hydrazono]methyl}-1-pyridiniumyl)-1-butanesulfonate,

4-{4-[N-methyl-N-phenylethanehydrazonoyl]-1-pyridiniumyl}-1-butanesulfonate,

4-{3-[N-methyl-N-phenylethanehydrazonoyl]-1-pyridiniumyl}-1-butanesulfonate,

4-{2-[N-methyl-N-phenylethanehydrazonoyl]-1-pyridiniumyl}-1-butanesulfonate,

4-{4-[N-phenylethanehydrazonoyl]-1-pyridiniumyl}-1-butanesulfonate,

4-{3-[N-phenylethanehydrazonoyl]-1-pyridiniumyl}-1-butanesulfonate,

4-{2-[N-phenylethanehydrazonoyl]-1-pyridiniumyl}-1-butanesulfonate,

4-(2-{[methyl(phenyl)hydrazono]methyl}-1,3-thiazol-3-ium-3-yl)-1-butanesulfonate,

4-(1-methyl-2-{[methyl(phenyl)hydrazono]methyl}-1H-imidazol-3-ium-3-yl)-1-butanesulfonate,

4-(2-{[methyl(phenyl)hydrazono]methyl}-1,3-oxazol-3-ium-3-yl)-1-butanesulfonate,

4-(4-methyl-5-{[methyl(phenyl)hydrazono]methyl}-4H-1,2,4-triazol-1-ium-1-yl)-1-butanesulfonate,

4-(4-{[methyl(phenyl)hydrazono]methyl}-1-quinoliniumyl)-1-butanesulfonate,

4-(2-{[methyl(phenyl)hydrazono]methyl}-1-quinoliniumyl)-1-butanesulfonate,

4-{4-[(2,3-dihydro-1H-indol-1-ylimino)methyl]-1-pyridiniumyl}-1-butanesulfonate,

4-(4-{[(2,2,3,3-tetramethyl-2,3-dihydro-1H-indol-1-yl)imino]methyl}-1-pyridiniumyl)-1-butanesulfonate,

4-(3,3-dimethyl-2-{[methyl(phenyl)hydrazono]methyl}-3H-indolium-1-yl)-1-butanesulfonate,

4-(2-{[(4-methoxyphenyl)(methyl)hydrazono]methyl}-3,3-dimethyl-3H-indolium-1-yl)-1-butanesulfonate,

4-(3-methyl-6-{[methyl(phenyl)hydrazono]methyl}-2-oxo-2,3-dihydropyrimidin-1-ium-1-yl)-1-butanesulfonate,

4-(1-methyl-7-{[methyl(phenyl)hydrazono]methyl}-1H-indazol-2-ium-2-yl)-1-butanesulfonate,

3-(4-{[methyl(phenyl)hydrazono]methyl}-1-pyridiniumyl)-1-propanesulfonate,

3-(3-{[methyl(phenyl)hydrazono]methyl}-1-pyridiniumyl)-1-propanesulfonate,

3-(2-{[methyl(phenyl)hydrazono]methyl}-1-pyridiniumyl)-1-propanesulfonate,

3-(4-{[(4-methoxyphenyl)(methyl)hydrazono]methyl}-1-pyridiniumyl)-1-propanesulfonate,

3-(3-{[(4-methoxyphenyl)(methyl)hydrazono]methyl}-1-pyridiniumyl)-1-propanesulfonate,

3-(2-{[(4-methoxyphenyl)(methyl)hydrazono]methyl}-1-pyridiniumyl)-1-propanesulfonate,

3-(4-{[(2-methoxyphenyl)(methyl)hydrazono]methyl}-1-pyridiniumyl)-1-propanesulfonate,

3-(3-{[(2-methoxyphenyl)(methyl)hydrazono]methyl}-1-pyridiniumyl)-1-propanesulfonate,

3-(2-{[(2-methoxyphenyl)(methyl)hydrazono]methyl}-1-pyridiniumyl)-1-propanesulfonate,

3-(4-{[(4-hydroxyphenyl)(methyl)hydrazono]methyl}-1-pyridiniumyl)-1-propanesulfonate,

3-(3-{[(4-hydroxyphenyl)(methyl)hydrazono]methyl}-1-pyridiniumyl)-1-propanesulfonate,

3-(2-{[(4-hydroxyphenyl)(methyl)hydrazono]methyl}-1-pyridiniumyl)-1-propanesulfonate,

3-(4-{[methyl(4-methylphenyl)hydrazono]methyl}-1-pyridiniumyl)-1-propanesulfonate,

3-(3-{[methyl(4-methylphenyl)hydrazono]methyl}-1-pyridiniumyl)-1-propanesulfonate,

3-(2-{[methyl(4-methylphenyl)hydrazono]methyl}-1-pyridiniumyl)-1-propanesulfonate,

3-(4-{[(4-chlorophenyl)(methyl)hydrazono]methyl}-1-pyridiniumyl)-1-propanesulfonate,

3-(3-{[(4-chlorophenyl)(methyl)hydrazono]methyl}-1-pyridiniumyl)-1-propanesulfonate,

3-(2-{[(4-chlorophenyl)(methyl)hydrazono]methyl}-1-pyridiniumyl)-1-propanesulfonate,

3-(4-{[methyl(4-nitrophenyl)hydrazono]methyl}-1-pyridiniumyl)-1-propanesulfonate,

3-(3-{[methyl(4-nitrophenyl)hydrazono]methyl}-1-pyridiniumyl)-1-propanesulfonate,

3-(2-{[methyl(4-nitrophenyl)hydrazono]methyl}-1-pyridiniumyl)-1-propanesulfonate,

3-{4-[(phenylhydrazono)methyl]-1-pyridiniumyl}-1-propanesulfonate,

3-{3-[(phenylhydrazono)methyl]-1-pyridiniumyl}-1-propanesulfonate,

3-{2-[(phenylhydrazono)methyl]-1-pyridiniumyl}-1-propanesulfonate,

3-(4-{[(4-methoxyphenyl)hydrazono]methyl}-1-pyridiniumyl)-1-propanesulfonate,

3-(3-{[(4-methoxyphenyl)hydrazono]methyl}-1-pyridiniumyl)-1-propanesulfonate,

3-(2-{[(4-methoxyphenyl)hydrazono]methyl}-1-pyridiniumyl)-1-propanesulfonate,

3-{4-[N-methyl-N-phenylethanehydrazonoyl]-1-pyridiniumyl}-1-propanesulfonate,

3-{3-[N-methyl-N-phenylethanehydrazonoyl]-1-pyridiniumyl}-1-propanesulfonate,

3-{2-[N-methyl-N-phenylethanehydrazonoyl]-1-pyridiniumyl}-1-propanesulfonate,

3-{4-[N-phenylethanehydrazonoyl]-1-pyridiniumyl}-1-propanesulfonate,

3-{3-[N-phenylethanehydrazonoyl]-1-pyridiniumyl}-1-propanesulfonate,

3-{2-[N-phenylethanehydrazonoyl]-1-pyridiniumyl}-1-propanesulfonate,

3-(2-{[methyl(phenyl)hydrazono]methyl}-1,3-thiazol-3-ium-3-yl)-1-propanesulfonate,

3-(1-methyl-2-{[methyl(phenyl)hydrazono]methyl}-1H-imidazol-3-ium-3-yl)-1-propanesulfonate,

3-(2-{[methyl(phenyl)hydrazono]methyl}-1,3-oxazol-3-ium-3-yl)-1-propanesulfonate,

3-(4-methyl-5-{[methyl(phenyl)hydrazono]methyl}-4H-1,2,4-triazol-1-ium-1-yl)-1-propanesulfonate,

3-(4-{[methyl(phenyl)hydrazono]methyl}-1-quinoliniumyl)-1-propanesulfonate,

3-(2-{[methyl(phenyl)hydrazono]methyl}-1-quinoliniumyl)-1-propanesulfonate,

3-{4-[(2,3-dihydro-1H-indol-1-ylimino)methyl]-1-pyridiniumyl}-1-propanesulfonate

3-(4-{[(2,2,3,3-tetramethyl-2,3-dihydro-1H-indol-1-yl)imino]methyl}-1-pyridiniumyl)-1-propanesulfonate,

3-(3,3-dimethyl-2-{[methyl(phenyl)hydrazono]methyl}-3H-indolium-1-yl)-1-propanesulfonate,

3-(2-{[(4-methoxyphenyl)(methyl)hydrazono]methyl}-3,3-dimethyl-3H-indolium-1-yl)-1-propanesulfonate,

3-(3-methyl-6-{[methyl(phenyl)hydrazonol]methyl}-2-oxo-2,3-dihydropyrimidin-1-ium-1-yl)-1-propanesulfonate,

3-(1-methyl-7-{[methyl(phenyl)hydrazono]methyl}-1H-indazol-2-ium-2-yl)-1-propanesulfonate,

4-(4-{[(3-methyl-1,3-benzothiazol-2(3H)-ylidene)hydrazono]methy}-1-pyridiniumyl)-1-butanesulfonate,

4-(3-{[(3-methyl-1,3-benzothiazol-2(3H)-ylidene)hydrazono]methyl}-1-pyridiniumyl)-1-butanesulfonate,

4-(4-{[(3,4-dimethyl-1,3-thiazol-2(3H)-ylidene)hydrazono]methyl}-1-pyridiniumyl)-1-butanesulfonate,

4-(3-{[(3,4-dimethyl-1,3-thiazol-2(3H)-ylidene)hydrazono]methyl}-1-pyridiniumyl)-1-butanesulfonate,

4-(4-{[(3,4,5-trimethyl-1,3-thiazol-2(3H)-ylidene)hydrazono]methy}-1-pyridiniumyl)-1-butanesulfonate,

4-(3-{[(3,4,5-trimethyl-1,3-thiazol-2(3H)-ylidene)hydrazono]methyl}-1-pyridiniumyl)-1-butanesulfonate,

4-(1-methyl-2-{[2-(3-methyl-1,3-benzothiazol-2(3H)-ylidene)hydrazono]methy}-1H-imidazol-3-ium-3-yl)-1-butanesulfonate,

4-(2-{[2-(3,4-dimethyl-1,3-thiazol-2(3H)-ylidene)hydrazono]methy}-1-methyl-1H-imidazol-3-ium-3-yl)-1-butanesulfonate,

4-(2-{[2-(3,4,5-trimethyl-1,3-thiazol-2(3H)-ylidene)hydrazono]methyl}-1-methyl-1H-imidazol-3-ium-3-yl)-1-butanesulfonate,

4-{4-[({bis[4-(dimethylamino)phenyl]methylene}hydrazono)methyl]-1-pyridiniumyl}-1-butanesulfonate,

4-{3-[({bis[4-(dimethylamino)phenyl]methylene}hydrazono)methyl]-1-pyridiniumyl}-1-butanesulfonate,

4-{4-[(9H-fluoren-9-ylidenehydrazono)methyl]-1-pyridiniumyl}-1-butanesulfonate,

4-{4-[({bis[4-(dimethylamino)phenyl]methylene}hydrazono)methyl]-1-quinoliniumyl}-1-butanesulfonate,

3-(4-{[(3-methyl-1,3-benzothiazol-2(3H)-ylidene)hydrazono]methyl}-1-pyridiniumyl)-1-propanesulfonate,

3-(3-{[(3-methyl-1,3-benzothiazol-2(3H)-ylidene)hydrazono]methyl}-1-pyridiniumyl)-1-propanesulfonate,

3-(4-{[(3,4-dimethyl-1,3-thiazol-2(3H)-ylidene)hydrazono]methyl}-1-pyridiniumyl)-1-propanesulfonate,

3-(3-{[(3,4-dimethyl-1,3-thiazol-2(3H)-ylidene)hydrazono]methyl}-1-pyridiniumyl)-1-propanesulfonate,

3-(4-{[(3,4,5-trimethyl-1,3-thiazol-2(3H)-ylidene)hydrazono]methyl}-1-pyridiniumyl)-1-propanesulfonate,

3-(3-{[(3,4,5-trimethyl-1,3-thiazol-2(3H)-ylidene)hydrazono]methyl}-1-pyridiniumyl)-1-propanesulfonate,

3-(1-methyl-2-{[2-(3-methyl-1,3-benzothiazol-2(3H)-ylidene)hydrazono]methyl}-1H-imidazol-3-ium-3-yl)-1-propanesulfonate,

3-(2-{[2-(3,4-dimethyl-1,3-thiazol-2(3H)-ylidene)hydrazono]methyl}-1-methyl-1H-imidazol-3-ium-3-yl)-1-propanesulfonate,

3-(2-{[2-(3,4,5-trimethyl-1,3-thiazol-2(3H)-ylidene)hydrazono]methyl}-1-methyl-1H-imidazol-3-ium-3-yl)-1-propanesulfonate,

3-{4-[({bis[4-(dimethylamino)phenyl]methylene}hydrazono)methyl]-1-pyridiniumyl}-1-propanesulfonate,

3-{3-[({bis[4-(dimethylamino)phenyl]methylene}hydrazono)methyl]-1-pyridiniumyl}-1-propanesulfonate,

3-{4-[(9H-fluoren-9-ylidenehydrazono)methyl]-1-pyridiniumyl}-1-propanesulfonate and

3-{4-[({bis[4-(dimethylamino)phenyl]methylene}hydrazono)methyl]-1-quinoliniumyl}-1-propanesulfonate.

6. The agent according to claim 1 , wherein the zwitterionic azomethine dye of the formula (I), (II), or (III) is present in an amount of from about 0.01% to about 10% by weight.

7. The agent according to claim 1 , additionally comprising at least one direct dye which is selected from the group consisting of nitro dyes, azo dyes, anthraquinone dyes, triphenylmethane dyes, basic dyes and acidic dyes.

8. The agent according to claim 7 , wherein the additional direct dye is present in a total amount of from about 0.01% to about 15% by weight.

9. The agent according to claim 2 , wherein in the formula (I), (II), and (III) R13 is hydrogen and n is 2 or 3.

10. The agent according to claim 2 , wherein the zwitterionic azomethine dye of the formula (I), (II), or (III) is selected from the group consisting of

4-(4-{[methyl(phenyl)hydrazono]methyl}-1-pyridiniumyl)-1-butanesulfonate,