Patent ID: 9663615
Date: 2017-05-30
CPC Classifications: C08G

Claim:
1. A method of making a branched polyester resin comprising: contacting a monomer bisphenol A (BPA) with a mixture of cyclic alkylene carbonates in the presence of a base to obtain a reaction mixture comprising two or more alkoxylated BPA monomers; copolymerizing the two or more alkoxylated BPA monomers with a diacid in the presence of a catalyst to obtain a copolymer; and condensing the copolymer with an acid anhydride, wherein the acid anhydride comprises a triacid or a tetraacid; wherein the branched polyester resin has an acid value of from about 8 mg KOH/g to about 14 mg KOH/g.