BIAXIALLY ORIENTED POLYETHYLENE-2,6-NAPHTHALATE FILM FOR MAGNETIC RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To provide a polyethylene-2,6-naphthalate film for a magnetic recording medium solved in the point of issue possessed by a conventional polyethylene-2,6-naphthalate film and improved in delamination resistance while holding high elastic modulus. SOLUTION: A film layer is formed to at least the single surface of a biaxially oriented film comprising copolymerized polyethylene-2,6-naphthalate wherein 2,6-naphthalenedicarboxylic acid is a main dicarboxylic acid component and ethylene glycol is a main glycol component and 0.1-10 mol.% (with respect to the total amt. of the total carboxylic acid component) of an isophthalic acid component is contained as a copolymerizing component and the content of a diethylene glycol component is 3 mol.% (with respect to glycol total amt. of the total glycol component). The film layer is a coating film formed from a water soluble or water dispersible resin containing inert particles with an average particle size of 5-100 nm and has 1×106-1×109/mm2 of projections caused by inert particles on the surface thereof and the surface center line average roughness of the film layer is 0.1-2 nm.