Process for the production of dis-azo pigment

摘要

A process for the production of a dis-azo pigment having excellent dispersibility, high tinting strength and high masking strength, by a simple method under an improved working environment, which is improved in a drying step and can omit the pulverization step of a conventional process, the present process comprising (a) a first step of forming an aqueous paste or slurry containing a synthesized dis-azo pigment into fine particles under hot air at 100 DEG to 300 DEG C. for a short period of time within 0.5 hour, and at the same time, removing water from the formed fine particles to form a powder, and (b) a second step of keeping the powder under heat at 50 DEG to 150 DEG C. for 0.5 to 10 hours.