| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a polyester chip having excellent hydrolysis resistance and hardly causing surface defects due to bubbles when molded into a film or the like. <P>SOLUTION: This method for producing the polyester chip includes: a first process of using an aromatic dicarboxylic acid as a principal acid component, using a 2-4C alkylene glycol as a principal glycol component, and adding 0.1-5.0 mol% of an oxalic acid glycol ester (PAO) for the whole acid components during a polycondensation reaction; a second process of continuing the polycondensation reaction until intrinsic viscosity of 0.60-0.85 dL/g is attained in melt polymerization; and a third process of cutting the reaction product into chips. In the first process, the PAO is heated at ≥100°C to be melted and added in the form of liquid under reduced pressure when the intrinsic viscosity of a polyester reaches ≥0.2 (dL/g). <P>COPYRIGHT: (C)2013,JPO&INPIT |
