Patent ID: 9023953
Filing Date: 2015-05-05
Classification: C08G

Abstract:
1. A method of producing a poly(lactic acid) resin comprising: carrying out direct polycondensation using lactic acid as a main raw material with a tin organic carboxylate and methanesulfonic acid to prepare a crystallized prepolymer having a weight average molecular weight of 5,000 to 25,000, an enthalpy of fusion ΔHm of 50 to 65 J/g and an acid value A mol/ton satisfying (1): wherein Mw represents weight average molecular weight of said crystallized prepolymer and said crystallized prepolymer is a pellet having a maximum diameter of about 1.5 to 6 mm; and subjecting said crystallized prepolymer to solid-phase polymerization.