Abstract: In the present invention, there are obtained aliphatic polyesters having a controlled thermal decomposing property, hydrolizability, and biodegradability, in which OH terminals and COOH terminals are decreased to 50% and 30%, respectively, through a ring-opening polymerization of a lactone and lactide by a mono alcohol having a high boiling point or a metal alkoxide, or by further decreasing both terminals through combining produced polymer terminals with a diisocyanate and, from a composition containing the polyesters, there is obtained a particle-state composition for agriculture and gardening in which a duration period of a fertilizing effect can be controlled, and which is not remained in soil by decomposition.

Abstract: In the present invention, there are obtained aliphatic polyesters having a controlled thermal decomposing property, hydrolizability, and biodegradability, in which OH terminals and COOH terminals are decreased to 50% and 30%, respectively, through a ring-opening polymerization of a lactone and lactide by a mono alcohol having a high boiling point or a metal alkoxide, or by further decreasing both terminals through combining produced polymer terminals with a diisocyanate and, from a composition containing the polyesters, there is obtained a particle-state composition for agriculture and gardening in which a duration period of a fertilizing effect can be controlled, and which is not remained in soil by decomposition.

Abstract: The present invention relates to a polyester block copolymer composition which is obtained by reacting 0.5 to 5.0 parts by weight of an epoxy compound (C) having two or more functionalities with 100 parts by weight of a polyester block copolymer (P) having an acid value of 0 to 5 mgKOH/g obtained by reacting a crystalline aromatic polyester (A) having a hydroxyl group at a molecular terminal with a lactone (B) and optionally with a polyfunctional compound (D) having three or more groups selected among carboxyl, hydroxyl, and/or ester groups thereof. The composition has such excellent moldability that it is applicable to molding techniques including blow molding without arousing any trouble. It is satisfactory in heat resistance, water resistance, impact resistance, or flame retardancy, and has rubber-like elasticity.

Abstract: In the present invention, there are obtained aliphatic polyesters having a controlled thermal decomposing property, hydrolizability, and biodegradability, in which OH terminals and COOH terminals are decreased to 50% and 30%, respectively, through a ring-opening polymerization of a lactone and lactide by a mono alcohol having a high boiling point or a metal alkoxide, or by further decreasing both terminals through combining produced polymer terminals with a diisocyanate and, from a composition containing the polyesters, there is obtained a particle-state composition for agriculture and gardening in which a duration period of a fertilizing effect can be controlled, and which is not remained in soil by decomposition.

Abstract: In the present invention, there are obtained aliphatic polyesters having a controlled thermal decomposing property, hydrolizability, and biodegradability, in which OH terminals and COOH terminals are decreased to 50% and 30%, respectively, through a ring-opening polymerization of a lactone and lactide by a mono alcohol having a high boiling point or a metal alkoxide, or by further decreasing both terminals through combining produced polymer terminals with a diisocyanate and, from a composition containing the polyesters, there is obtained a particle-state composition for agriculture and gardening in which a duration period of a fertilizing effect can be controlled, and which is not remained in soil by decomposition.