Patent ID: 8173753
Filing Date: 2012-05-08
Classification: C08G

Abstract:
1. A method for producing an aliphatic polyester resin using a sulfonic acid group-containing compound as a catalyst, comprising: melt polymerizing a raw material monomer, wherein an addition amount of the sulfonic acid group-containing compound during melt polymerization is 300 to 3000 ppm with respect to the raw material monomer calculated as sulfur atoms; and solid phase polymerizing a resulting melt polymer, wherein the content of the sulfonic acid group-containing compound after solid phase polymerization is 300 to 3000 ppm with respect to a produced aliphatic polyester resin calculated as sulfur atoms, and a residual rate of the sulfonic acid group-containing compound after solid phase polymerization is more than 50% wherein the melt polymerization is continuously performed under a condition including at least 2 stages, and the solid phase polymerization is continuously performed under the condition including at least the 2 stages: Melt polymerization: Condition 1 140° C. to 160° C., 13.3 to 66.6 kPa; Condition 2 160° C. to 180° C., 1.3 to 6.5 kPa, Solid phase polymerization: Condition 1 130° C. to 150° C.; Condition 2 higher than 150° C. to 165° C.