Organic pigment compositions containing an azo compound with a heterocyclic substituent

Claim 1

A pigment composition comprising: (a) an organic pigment selected from the group consisting of phthalocyanine, quinacridone, anthraquinone, and azo pigments; and (b) an azo compound of the formula A--N=N--B].sub.n wherein n is 1 or 2, A and B are radicals of either a coupling component or a diazo component, wherein the coupling component is selected from the group consisting of acetoacetyl arylamide, 1-alryl-pyrazol-5-one, β-naphthol, 3-hydroxy-2-naphthoic acid anilide, 1,3- or 1,4-bisacetoacetyl-phenylene diamine or wherein each of said acetoacetyl arylamide, 1-aryl-pyrazol-5-one, β-naphthol, 3-hydroxy-2-naphthoic acid anilide or 1,3- or 1,4-biasacetoacetyl-phenylene diamine is substituted by chloro, bromo, alkyl having 1 to 6 carbon atoms, alkoxy having 1 to 6 carbon atoms, nitro, carboxylic acid, sulphonic acid, alkali metal carboxylate, alkali metal sulphonate, or arylazo, and a compound of the formula ##STR11## wherein Z is a group of atoms necessary to complete a benzimidazole, pyridine, benzodiazepine, quinoline, isoquinoline or naphthimidazole group; and the diazo component is derived from an amine A(NH 2 ) n or B(NH 2 ) where A and B are selected from the group consisting of naphthyl, phenyl, diphenyl, or wherein said naphthyl, phenyl, and diphenyl are each substituted by chloro, bromo, alkyl having 1 to 6 carbon atoms, alkoxy having 1 to 6 carbon atoms, nitro, carboxylic acid, sulfonic acid, alkali metal carboxylate, alkali metal sulphonate, or arylazo and a compound of the formula, ##STR12## provided where A is the coupling component, B is the diazo component, when A is the diazo component, B is the coupling component and azo compound (b) must contain at least one benzimidazole, pyridine, benzodiazepine, quinoline, isoquinoline or naphthimidazole group; wherein said azo compound is present in an amount of from 0.5% to 20% by weight, based upon the weight of said organic pigment(a).