BIODEGRADABLE POLYESTER COPOLYMER AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To obtain a biodegradable polyester copolymer excellent in biodegradability and workability having excellent properties such as strength and elongation and useful for PET bottles, etc., by performing transesterification between polyethylene terephthalate and a specific dicarboxylic anhydride- ethylene oxide copolymer. SOLUTION: The objective polymer is obtained by performing transesterification between (A) polyethylene terephthalate and (B) a dicarboxylic anhydride-ethylene oxide copolymer having an ethylene oxide content of 50-100 mol% (preferably 51-80 mol%), preferably a succinic anhydride-ethylene oxide copolymer represented by the formula (n>1; and m is an integer of >=2). The transesterification mixing ratio by weight of the component B to the component A is preferably 0.20-8.00.