Purification process of aliphatic polyester
AssigneeMitsui Toatsu Chemicals, Inc.
InventorsHiroshi Suizu, Masatoshi Takagi, Masanobu Ajioka, Akihiro Yamaguchi
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Abstract
A purification process of an aliphatic polyester prepared in the presence of a catalyst from a hydroxycarboxylic acid or a cyclic ester of a hydroxycarboxylic acid, or a combination of an aliphatic polyhydric alcohol with an aliphatic polybasic acid, or a mixture of these compounds, comprising deactivating the catalyst while maintaining the aliphatic polyester in a molten or dissolved state, or insolubilizing and separating the catalyst and successively removing low molecular compounds. The process can provide aliphatic polyester which has a low content of unreacted monomers and low molecular weight compounds and is excellent in heat resistance and weatherability.
Claims14
A purification process of an aliphatic polyester prepared in the presence of a catalyst from
- (i) an aliphatic hydroxycarboxylic acid,
- (ii) a cyclic ester of the aliphatic hydroxycarboxylic acid,
- (iii) a combination of an aliphatic polyhydric alcohol and an aliphatic polybasic acid, or
- (iv) a mixture of compounds selected from the above (i) to (iii), which comprises deactivating the catalyst or insolubilizing and separating the catalyst, while maintaining the aliphatic polyester in a molten or a dissolved state and successively removing a low molecular weight compound by distillation under reduced pressure.
Dependencies are inferred from the claim text.