Polyhydroxycarboxylic acid and preparation process thereof
AssigneeMitsui Toatsu Chemicals, Inc.
InventorsKatashi Enomoto, Masanobu Ajioka, Akihiro Yamaguchi
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Abstract
A process for preparing polyhydroxycarboxylic acid by conducting a dehydration condensation of a hydroxycarboxylic acid or an oligomer thereof in a reaction mixture containing an organic solvent substantially in the absence of water and the polyhydroxycarboxylic acid thus obtained. The process provides polyhydroxycarboxylic acid having excellent properties and processability.
Claims37
A process for preparing polyhydroxycarboxylic acid comprising conducting dehydration condensation of a hydroxycarboxylic acid or an oligomer thereof in a reaction mixture containing an organic solvent and less than 500 ppm of water to obtain polyhydroxycarboxylic acid having a weight average molecular weight of at least about 15,000.
A degradable polyhydroxycarboxylic acid prepared directly from a reaction mixture consisting essentially of a hydroxycarboxylic acid or a oligomer thereof, organic solvent and less than 500 ppm of water, said polyhydroxycarboxylic acid having a weight average molecular weight of at least about 50,000.
A degradable polyhydroxycarboxylic acid consisting essentially of D- and L-lactic acid, having .sup.13 C-NMR absorbance of around 169.27 ppm, 169.31 ppm, 169.42 ppm, 169.49 ppm and 169.66 ppm.
Dependencies are inferred from the claim text.