BIAXIALLY ORIENTED POLYESTER FILM

摘要

PROBLEM TO BE SOLVED: To provide a biaxially oriented polyester film capable of sufficiently corresponding to the high speed processing of a magnetic recording medium. SOLUTION: A film based on polyester A is characterized by that the content of particles forming projections on at least one surface of the film is 0.3wt.% or less, the center line average rougnhness Ra of at least one surface thereof is 0.5-100nm, the interval Sm between the projections on the surface of the film in the lateral direction thereof is 20μm or less, the contact angle of water to the surface of the film is 70-100 deg. and the coefficient of friction of the film to a plastic guide pin is 0.3 or less.