| 摘要 |
PROBLEM TO BE SOLVED: To provide a glycolic acid copolymer not getting colored so much and capable of maintaining its high quality even after subjected to a melt processing at a relatively high temperature, and a method for producing the same. SOLUTION: The glycolic acid copolymer has a weight-average molecular weight of 50,000 or more, contains glycolic acid monomer units of 75 mol% or more, and has a rate of change of coloring of 110 to 300% before and after heated for melting at 230°C for 5 min. The glycolic acid copolymer is produced by adding a triaryl phosphite compound when the weight-average molecular weight thereof reaches 30,000 or more in the course of polycondensation reaction. COPYRIGHT: (C)2008,JPO&INPIT
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