METHOD FOR PRODUCING POLYBUTYLENE TEREPHTHALATE, FILM AND MONOFILAMENT

摘要

PROBLEM TO BE SOLVED: To provide a method for producing polybutylene terephthalate, capable of radically reducing foreign materials in the polybutylene terephthalate while maintaining its productivity. SOLUTION: This method for producing polybutylene terephthalate by performing an esterification reaction of terephthalic acid with 1,4-butanediol continuously to obtain an oligomer, and performing a polycondensation reaction of the oligomer to obtain polybutylene terephthalate is provided by installing a filter in a flowing passage of a prepolymer having≥90% esterification rate and≤0.5 intrinsic viscosity, filtering at least a part of solid material having≥20μm particle diameter and performing the esterification reaction so as to make it satisfy formula (I): P/q≥1,500kJ/m3(I). COPYRIGHT: (C)2004,JPO