POLYBUTYLENE TEREPHTHALATE AND METHOD FOR PRODUCTION THEREOF, AND COMPOSITION COMPRISING THE SAME AND FILM

摘要

A polybutylene terephthalate (PBT) which contains titanium and has a titanium content of 33 ppm or less; and a composition comprising the polybutylene terephthalate. In a preferred embodiment, the polybutylene terephthalate exhibits a crystallization temperature in the course of the decrease of temperature of 170 to 190°C, has a concentration of a terminal vinyl group of 0.1 to 10 mueq/g, exhibits a haze of its specific solution of 10 % or less, exhibits an increase of the concentration of a terminal carboxyl group of 0.1 to 30 mueq/g after being heat-treated under specific conditions, and contains foreign particles having a size of 5 mum or larger in an amount of 50 pieces/10 g-polymer or less. The PBT and a composition comprising the PBT are excellent in color tone, hydrolysis resistance, heat stability, transparency and processability, and is reduced in the content of foreign matter, and thus can be suitably used for a film, a monofilament, a fiber, an electric or electronic part, an automobile part or the like.