Polyester film for high density magnetic recording medium

摘要

A polyester film suitable for a base of high density magnetic recording medium containing barium ferrite as a magnetic material characterized in that the centerline average roughness (Ra) is not more than 0.025 mu m and the F5 value in the longitudinal direction is not less than 14 kg/mm2 is disclosed wherein the polyester film exhibit excellent better durability when used with barium ferrite as a magnetic material.