| abstract |
[PROBLEMS] To achieve efficient polymerization by adding a small amount of a tin-based catalyst to an acid-based catalyst, in addition to having high volumetric efficiency and no problem of stirring due to high viscosity. Provide an excellent manufacturing method. The weight average molecular weight is from 2,000 to 100,00. A weight-average molecular weight of 50,000 comprising solid-phase polymerization of a crystallized aliphatic polyester prepolymer containing 50% or more of an aliphatic hydroxycarboxylic acid unit having 0 in the presence of a tin-based catalyst and an acid-based catalyst. ~ 1,000, A method for producing an aliphatic polyester containing 50% or more of 000 aliphatic hydroxycarboxylic acid units. |