PROCESS FOR PRODUCING HIGHLY CONCENTRATED AQUEOUS SOLUTION OF CATIONIC AZO DYE

摘要

A process for the manufacture of highly concentrated aqueous solutions of specific cationic azo dyes is described. The solutions are prepared by diazotising a diazo component in sulphuric acid solution, coupling it with a coupling component, allowing a bicarbonate to act on the resulting azo dye and, using an organic acid, converting the dye bicarbonate into the dye salts of this acid.