Process for preparing polyester resins cured at low temperature and powder coating composition thereof

摘要

A process for preparing polyester resins comprises (1) reacting a mixture of organic carboxylic monomers having at least two reactive carboxyl groups with a mixture composed of at least two aliphatic alcohols having at least two hydroxyl groups to form a prepolymer, and (2) reacting the prepolymer with a mixture composed of pyromellitic dianhydride and adipic acid or azelaic acid to form polyester resins.