| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a polyester, capable of efficiently carrying out polymerization in a high volume efficiency without causing a problem of stirring resulting from high viscosity at all by adding a small amount silver-based catalyst to an acid-based catalyst. SOLUTION: This method for producing an aliphatic polyester having 50,000 to 1,000,000 weight-average molecular weight, containing >=50% aliphatic hydroxycarboxylic acid unit comprises subjecting a crystallized aliphatic polyester prepolymer having 2,000 to 100,000 weight-average molecular weight, containing >=50% aliphatic hydroxycarboxylic acid unit to solid-phase polymerization in the presence of both a tin-based catalyst and an acid-based catalyst.
|
