Neutral and cationic naphthalene and colorants for keratin fibers containing these compounds

1. A naphthalene derivative selected from the group consisting of 3-methyl-2-{5-nitro-2-ketobenzo[cd]indol-1(2H)-yl}-1,3-benzothiazol-3-ium methylsulfate, 2-{5-(dimethylamino)-2-ketobenzo[cd]indol-1(2H)-yl}-3-methyl-1,3-benzothiazol-3-ium methylsulfate, 5-((E)-{1-[4-(dimethylamino)phenyl]-2-keto-1,2-dihydrobenzo-[cd]indol-6-yl}diazenyl)-4-hydroxy-1-(2-hydroxyethyl)-3,6,7-trimethyl-1H-pyrazolo[3,4-b]pyridin-7-ium methylsulfate, 1-{4-[bis(hydroxyethyl)amino]phenyl}-6-nitrobenzo[cd]indol-2(1H)-one, 3-{2-[ethyl-4-(6-nitro-2-ketobenzo[cd]indol-1(2H)-yl)anilino]ethyl}-1-methyl-1H-imidazol-3-ium bromide, 4-{(E)-[(1,3-diketo-2,3-dihydro-1H-benzo[de]isoquinolin-6-yl)imino]-methyl}-1-(2-hydroxyethyl)pyridinium bromide, 2-[4-((E)-{1-[4-(dimethylamino)phenyl]-2-keto-1,2-dihydrobenzo[cd]indol-5-yl}diazenyl) (ethyl)anilino]-N,N,N-trimethylethanaminium bromide, 2-[(3-methyl-1,3-benzothiazol-2(3H)-ylidene)amino]-6-nitro-1H-benzo[de]isoquinolin-1,3(2H)-dione, 2-(1,3-benzothiazol-2-yl)-6-nitro-1H-benzo[de]isoquinolin-1,3(2H)-dione 2-{2-[(2-hydroxyethyl)amino]-4-methoxyphenyl}-5-nitro-1H-benzo[de]isoquinolin-1,3(2H)-dione, and 3-{2-[ethyl-4-(6-nitro-1,3-diketo-1H-benzo-[de]isoquinolin-2(3H)-yl)anilino]ethyl}-1-methyl-1H-imidazol-3-ium bromide.

2. An agent comprising at least one naphthalene derivative as defined in claim 1 .

3. An agent as defined in claim 2 , and further comprising at least one oxidant.

4. An agent as defined in claim 3 , wherein the oxidant is selected from the group consisting of hydrogen peroxide and hydrogen peroxide adducts, persulfates and perborates.

5. An agent as defined in claim 2 , wherein the agent contains at least one natural or synthetic polymer or a modified polymer of natural origin commonly used in cosmetic agents.

6. An agent as defined in claim 5 , wherein the agent contains the polymer in an amount from 1 to 5 weight percent.

7. An agent as defined in claim 2 , wherein the agent contains the naphthalene derivative in an amount from 0.01 to 10 weight percent.

8. An agent as defined in claim 2 , wherein the agent is a hair colorant.