MAGNETIC RECORDING MEDIUM

摘要

PURPOSE:To obtain the titled magnetic recording medium having high wear resistance and high recording density by laminating a ferromagnetic metallic thin film and a protective layer on a plastic substrate having the surface roughness of <=300Angstrom mean roughness Rz of 10 points. CONSTITUTION:An org. lubricant such as sorbitan having 50-500Angstrom particle diameter is added to a coating liq. by 0.02-2wt% based on the liq. The solvent soln. added with a surfactant is coated on a plastic substrate 1 with nylon as the binder to form prescribed Rz. Then a high-permeability layer 2 of an Fe-Ni alloy is formed in about 0.5mum thickness, a vertical magnetic recording layer 3 of a Co-Cr alloy contg. 20wt% Cr is laminated in about 0.3mum thickness and a protective layer 4 of Co3O4 is further laminated in prescribed thickness in an oxidizing gas with Co as the target by reactive sputtering. The medium is thus completed.