POLYESTER FILM FOR MAGNETIC RECORDING MEDIUM AND MAGNETIC RECORDING TAPE

摘要

PROBLEM TO BE SOLVED: To obtain a polyester film for magnetic recording medium suitable for the production of a data storage tape with a low error rate. SOLUTION: The polyester film has fine surface projections of 10 to 50 nm height by 3×106 to 9×107 projections/mm2 on one surface (A) of the film. On the surface (A) of the polyester film, surface projections having >20 nm height are present by <=8×104 projections/mm2, and Ra of the surface (A) measured by an atomic force microscope is <=6 nm. The obtd. polyester film for a magnetic recording medium has <=7μm thickness.