| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an aliphatic polyester resin having high molecular weight and, in a preferred state, high melting point and excellent thermal stability and hue, and a method for efficiently producing the resin. <P>SOLUTION: The method for producing the aliphatic polyester resin includes the use of a sulfonic acid group-containing compound as a catalyst and contains a melt-polymerization step followed by a solid-phase polymerization step, wherein the addition amount of the sulfonic acid group-containing compound in the melt polymerization is 300-3,000 ppm based on a raw monomer in terms of sulfur atom, the content of the sulfonic acid group-containing compound after the solid-phase polymerization is 300-3,000 ppm based on the produced polymer in terms of sulfur atom, and the residual ratio of the sulfonic acid group-containing compound after the solid phase polymerization is >50%. In addition, the aliphatic polyester resin contains a sulfonic acid group-containing compound having two or more sulfonic acid groups in one molecule in an amount of 300-3,000 ppm based on the produced polymer in terms of sulfur atom. <P>COPYRIGHT: (C)2011,JPO&INPIT |
