| abstract |
PROBLEM TO BE SOLVED: To provide a method for producing an aliphatic polyester which is biodegradable, has a practically sufficiently high molecular weight, and is excellent in heat stability, tensile strength and the like. [Constitution] Aliphatic oxycarboxylic acids such as lactic acid and glycolic acid, aliphatic dicarboxylic acids such as succinic acid, and aliphatic or alicyclic diols such as ethylene glycol and 1,4-butanediol in the presence of a catalyst. And reacted in the absence of an organic solvent to contain 0.02 to 30 mol% of an aliphatic oxycarboxylic acid unit and a number average molecular weight of 10,000 to Produce 200,000 polyester copolymers. |