Kureha Corporation

Fumio Maeda

Yoshinori Suzuki

Takahiro Watanabe

Hiroyuki Sato

Tomohiro Hoshi

A process for producing an aliphatic polyester, comprising: subjecting at least two serial stages of bulk-phase ring-opening polymerization and a solid-phase polymerization step, wherein a cyclic ester held in a dry air atmosphere is supplied to a first reactor to perform a first stage polymerization, thereby obtaining a partially polymerized molten product, and the resultant partially polymerized molten product is supplied to a second reactor held under a dry inert gas atmosphere to perform a second stage polymerization. As a result, the production efficiency can be improved, while maintaining excellent properties of the aliphatic polyester product.

Aliphatic polyester manufacturing method

A process for producing an aliphatic polyester through ring-opening polymerization of a cyclic ester, wherein a partial polymer in a molten state is continuously introduced into a twin-screw stirring device to continuously obtain a partial polymer in a solid pulverized state, the partial polymer is subjected to solid-phase polymerization, and the resultant polymer is melt-kneaded together with a thermal stabilizer to be formed into pellets. As a result, an aliphatic polyester of a high molecular weight and with little discoloration is produced efficiently.

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Tokyo, Japan

Fumio Maeda