POLYESTER COMPOSITION AND BLOW MOLDED PRODUCT, SHEETLIKE MATERIAL AND ORIENTED FILM COMPOSED OF THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a polyester composition having excellent crystallization controllability and long-time continuous moldability during melt molding and a blow molded product, a sheetlike material and an oriented film obtained therefrom, having excellent transparency and heat-resistant dimensional stability, affording especially a shrinkage percentage of a mouth plug part of the blow molded product within an appropriate range and scarcely causing residual off- tastes and off-flavors when formed into a liquid container. SOLUTION: This polyester composition comprises chips (A) of a polyester having main repeating units which are ethylene terephthalate and 0.1-300 ppm of fines (B) of a polyester. The area intensity ratio As on the chip surfaces of an absorption band due to the trans form caused by internal rotation with a carbon-carbon bond of ethylene glycol unit as an axis in an infrared absorption spectrum to an absorption band due to the gauche form is 5.50-9.00 and the ratio As/Ac of the area intensity ratio As to the area intensity ratio Ac in the chip central part satisfies 0.70-1.00.