Process for the manufacture of a monoazo acetoacetylaminobenzimidazolone

摘要

An improved process for the manufacture of a monoazo acetoacetylaminobenzimidazolone pigment of the formula <IMAGE> 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.