MAGNETIC RECORDING MEDIUM

摘要

PURPOSE: To suppress the degeneration of the surface of a head and to maintain initial electromagnetic transducing characteristics even after repeated running by specifying the amt. of sulfate ions extracted at the time of immersion in pure water at a specified temp. for a specified time. CONSTITUTION: A magnetic layer consisting essentially of ferromagnetic powder and a binder is formed on a nonmagnetic substrate. This magnetic layer is formed by coating so that the amt. of sulfate ions extracted at the time of immersion in pure water at 30 deg.C for 1hr is regulated to <=100μg/m<2> . Since the resultant magnetic recording medium feeds a small amt. of a sulfur component to the surface of a head, even when the medium is allowed to run repeatedly along the head, the head is not degenerated and the initial electromagnetic transducing characteristics can be maintained. Superior recording and reproducing characteristics are therefore ensured in a short wavelength recording region.