Patent ID: 8609264
Filing Date: 2013-12-17
Classification: C08J,G11B,Y10T

Abstract:
1. A biaxially oriented polyester film comprising at least two polyetherimides and an islands-in-sea structure with an average island domain size of 30 to 200 nm, and a coefficient of hygroscopic expansion of 0 to 6 ppm/% RH at least either in a machine direction or in a transverse direction or' the film, wherein an amorphous resin forming the island domains with a diameter of 30 to 200 nm contains at least one resin selected from the group consisting of polyetherimides, polyimides and polyamideimides, glass transition temperature of the amorphous resin forming the island domains with a diameter of 30 to 200 nm is 220 to 245 degrees centigrade, and total mass of the island domains with a diameter of 30 to 200 nm is 0.5 to 15 mass %.