Process for the manufacture of a monoazo acetoacetylaminobenzimidazolone
AssigneeHoechst Aktiengesellschaft
InventorKlaus Hunger
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Abstract
An improved process for the manufacture of a monoazo acetoacetylaminobenzimidazolone pigment of the formula ##STR1## by coupling the components in an aqueous medium in the presence of an oxethylation product of an alcohol or alcohol mixture having from 8 to 14 carbon atoms and 3 to 10 mols of ethylene oxide, and heating the aqueous pigment suspension after complete coupling. The pigment thus obtained avoids an after-treatment in anhydrous organic solvents and has good tinctorial strength, high hiding power and good properties with respect to flow and dispersibility.
Claims8
A process for the manufacture of a pigment form of the azo compound of the formula I ##STR3## by coupling of diazotized anthranilic acid onto 5-acetoacetylamino-benzimidazolone in an aqueous medium followed by a thermal after-treatment, which consists of coupling in the presence of an oxethylation product of an alcohol or alcohol mixture having from 8 to 14 carbon atoms and 3 to 10 mols of ethylene oxide to form an aqueous pigment suspension, and heating the aqueous pigment suspension to 92.degree. to 100.degree. C. after the coupling is complete.
Dependencies are inferred from the claim text.