BIAXIALLY ORIENTED FILM

摘要

A biaxially oriented film (1) which is substantially formed from a polyethylene naphthalate copolymer comprising ethylene-2,6-naphthalate units in an amount of 90 to 99.9 mol% based on the total of all recurring units and an isophthalic acid component or a decalin-2,6-dicarboxylic acid component in an amount of 0.1 to 10 mol% based on the total of all dicarboxylic acid components and which has (2) Young's modulus of 500 kg/mm<2> or more in each of a longitudinal direction and a transverse direction, (3) a plane orientation coefficient of 0.230 to 0.275 and (4) a density of 1,350 g/cm<3> or more.