PURPOSE: To provide a thermoplastic polyester composition comprising a polyester containing organic polymer fine particles extremely fine in their particle diameters and inorganic particles having a specific particle diameter, and giving films excellent in flatness, lubricity and wear resistance.
CONSTITUTION: This thermoplastic polyester composition comprises (A) a thermoplastic polyester preferably consisting mainly of a polyethylene terephthalate, (B) organic polymer fine particles (preferably, styrene/ethylvinylbenzene/ divinylbenzene copolymer, etc.) having a particle diameter of 0.002-0.1μm, preferably 0.02-0.08μm, more preferably 0.002-0.07μm, preferably the heat-resistant organic polymer fine particles having a thermal decomposition temperature of ≥350°C, in an amount of 0.01-10wt.% based on the component A, and (C) inorganic particles (preferably silicon dioxide or calcium carbonate) having a particle diameter of 0.002-5μm in a B/C weight ratio of 1/(0.001-10). The biaxially oriented (laminated) polyester film comprising this composition.
SASAKI TOSHIHIRO
YOSHIDA MINORU
