Process for the preparation of polyhydroxycarboxylic acid copolymer resin
AssigneeNishikawa Rubber Co., Ltd.
InventorsJunzo Otera, Toru Yano, Hirokazu Yamamoto, Nobuyuki Sakuda
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Abstract
A process for the preparation of a readily hydrolyzable and/or biodegradable polyhydroxycarboxylic acid resin which can be used in agricultural materials, gardening materials, fishery materials, caking materials, medical instruments and materials, etc. and, even when discarded after use, which undergoes hydrolysis and/or is biodegraded into carbon dioxide, water, etc. Also disclosed are a hydrolyzable and/or biodegradable polyhydroxycarboxylic acid resin composition having an increased resin strength and melt viscosity, and a process for the preparation thereof.
Claims35
A process for the preparation of a polyhydroxycarboxylic acid resin, which comprises:
- adding a polymerization catalyst comprising a 1,3-substituted-1,1,3,3-tetraorganodistanoxane to a mixture of a hydroxycarboxylic acid and a metal oxide;
- and then
- heating the mixture with stirring under reduced pressure or in the presence of an organic solvent to prepare a copolymer resin.
A process for the preparation of a polyhydroxycarboxylic acid resin, which comprises:
- adding a polymerization catalyst comprising a 1,3-substituted-1,1,3,3-tetraorganodistanoxane to a hydroxycarboxylic acid;
- dehydrating or oligomerizing the hydroxycarboxylic acid having the polymerization catalyst added thereto;
- adding a metal oxide to the dehydrated or oligomerized hydroxycarboxylic acid to prepare a reaction mixture;
- and then
- heating the reaction mixture with stirring under reduced pressure or in the presence of an organic solvent to prepare a copolymer resin.
A process for the preparation of a polyhydroxycarboxylic acid resin, which comprises:
- adding a polymerization catalyst comprising a 1,3-substituted-1,1,3,3-tetraorganodistanoxane to a mixture of (a) at least one of a hydroxycarboxylic acid, a dimerized hydroxycarboxylic acid and an oligomerized hydroxycarboxylic acid with (b) a saccharide;
- and then
- dehydropolymerizing the mixture having the polymerization catalyst added thereto.
A process for the preparation of a polyhydroxycarboxylic acid resin, which comprises:
- adding a polymerization catalyst comprising a 1,3-substituted-1,1,3,3-tetraorganodistanoxane to a mixture of (a) at least one of a hydroxycarboxylic acid, a dimerized hydroxycarboxylic acid and an oligomerized hydroxycarboxylic acid with (b) a zinc compound;
- and then heating the mixture having added thereto the polymerization catalyst with stirring under reduced pressure or in a stream of nitrogen to effect polymerization thereof, or subjecting the mixture having added thereto the polymerization catalyst to azeotropic solution dehydropolymerization in an organic solvent.
A biodegradable resin composition comprising a polyhydroxycarboxylic acid resin having a filler added to the resin in an amount of from 1 to 300 parts by weight per 100 parts by weight of the resin.
A process for the preparation of a biodegradable resin composition, which comprises:
- adding a polymerization catalyst comprising a 1,3-substituted-1,1,3,3-tetraorganodistanoxane to (a) a hydroxycarboxylic acid, (b) a mixture of two or more hydroxycarboxylic acids, (c) a mixture of a hydroxycarboxylic acid and a saccharide or (d) a mixture of a hydroxycarboxylic acid and a metal hydroxide and/or an inorganic acid to prepare a reaction mixture;
- subjecting the reaction mixture to azeotropic dehydropolymerization in an organic solvent, or heating the reaction mixture with stirring under reduced pressure to synthesize a polyhydroxycarboxylic acid resin;
- and then
- adding a filler to the polyhydroxycarboxylic acid resin.
Dependencies are inferred from the claim text.