摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a biodegradable copolyester having a high molecular weight and a narrow molecular weight distribution; and a method for manufacturing a polyester in the presence of an RE compound catalyst component. <P>SOLUTION: The manufacturing method comprises the step (1) of adding to a reaction vessel the following monomers and a catalyst component Cat1 selected from the group consisting of compounds of Ti, Sb and Zn and a mixture thereof, to effect a transesterification and/or an esterification, the above monomers being (a) an aromatic dicarboxylic acid, an ester thereof, an anhydride thereof, or a mixture thereof, (b) an aliphatic diol, an alicyclic diol, or a mixture thereof, and (c) an aliphatic dicarboxylic acid, an alicyclic dicarboxylic acid, an ester thereof, an anhydride thereof, or a mixture thereof; the step (2) of prepolymerizing under vacuum a reaction system obtained in the step (1); and the step (3) of adding a catalyst component Cat2 selected from RE compounds and a mixture thereof to a prepolymerized product obtained in the step (2), to polycondensate them under a reduced pressure. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |