ALIPHATIC POLYESTER AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To obtain a polyester having excellent moldability and biodegradability by polymerizing a diol compound with a dicarboxylic acid and/or its ester compound in the presence of a polymerization catalyst comprising a titanium compound and a compound of group IIA in the periodic table. SOLUTION: The diol compound used is represented by the formula: HO-A1- OH (wherein A1 is a 2-10C aliphatic hydrocarbon group and is desirably 1,4- butanediol. The dicarboxylic acid (including an ester compound) is represented by the formula: HOOC-A2-COOH (wherein A2 is an 8-22C aliphatic hydrocarbon group) and is preforably eicosanedicarboxylic acid. The polymerization catalyst contains a Ti compound and an Mg compound in an Mg/Ti (atomic ratio) of 0.1-10. It is desirable that the Ti compound is tetra-n-butyl titanate, and that the Mg compound is magnesium acetate. The obtained polyester comprises repeating structural units of the formula: (-OA1OOCA2CO-) and has a number- average molecular weight of 10,000-300,000.