| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a high-molecular weight aliphatic hydroxycarboxylic acid polyester composed of an aliphatic hydroxycarboxylic acid or the hydroxycarboxylic acid and a specific aliphatic polyhydric alcohol and a specific aliphatic polybasic acid or its anhydride. SOLUTION: The method for producing a high-molecular weight aliphatic polyhydroxycarboxylic acid is composed of: a step to produce a low-molecular weight prepolymer by the dehydrative polycondensation reaction of an aliphatic hydroxycarboxylic acid, or an aliphatic hydroxycarboxylic acid, an aliphatic polyhydric alcohol having≥3 hydroxy groups and an aliphatic polybasic acid having≥2 carboxy groups or its anhydride, or an aliphatic hydroxycarboxylic acid, an aliphatic polybasic acid having≥3 carboxy groups or its anhydride and an aliphatic polyhydric alcohol having≥2 hydroxy groups; a step to crystallize the low-molecular prepolymer; and a step to perform the dehydrative polycondensation reaction of the crystallized prepolymer in solid state in the presence of an organic sulfonic acid-based compound catalyst. COPYRIGHT: (C)2008,JPO&INPIT
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