Preparation of polymaleic acids from maleic anhydride in the presence of acetic anhydride and of hydrogen peroxide

摘要

An improved process for the preparation of polymaleic acids having molecular weights of from 200 to 1,500, by polymerizing maleic anhydride in acetic anhydride in the presence of from 0.2 to 0.5 mole of hydrogen peroxide per mole of maleic anhydride, at from 80 DEG to 140 DEG C., and builders and encrustation inhibitors comprising the polymaleic acids prepared by the said process, for use in detergents.