DISCOID MAGNETIC RECORDING MEDIUM

摘要

PURPOSE:To improve the electromagnetic transducing characteristics of a magnetic recording medium by regulating the thickness of the medium to a prescribed range, the bending hardness of the medium to a prescribed range and the average surface roughness of the magnetic layer to a prescribed value or below. CONSTITUTION:This discoid magnetic recording medium contains magnetic metallic powder as the magnetic powder and has 20-60mum thickness and 2.0-200g.mm bending hardness (stiffness). The film of plastic such as polyethylene terephthalate or polypropylene or metallic foil such as Al foil is used as the nonmagnetic support. The preferred thickness of the support is 10-55mum. The magnetic layer of the medium is required to have <=0.03mum average surface roughness Ra. In case of >0.03mum average surface roughness, the wear of a magnetic head is accelerated.