| 摘要 |
PURPOSE:To obtain a magnetic recording medium which has high coercive force, an excellent squareness ratio, and a low noise level, by vacuum-depositing ferromagnetic metal on the surface of a nonmagnetic base which has surface roughness and the number of projections within specific ranges. CONSTITUTION:The surface roughness CLA[center line average (unit; mu) measured in accordance with JISB0601]of a base a nonmagnetic material, such as a polyester film, meets requirements shown in inequalityI, and the number (unit; number/mm.<2>) of the projection height hmu of projections meets requirements as whon bt inequality II. For this purpose, Co or Co alloy, etc. is vacuum- deposited on the surface of the base (obtained by kneading powder or by catalytic composition during polyester synthesis) having a dispersed inert inorganic compound (oxide such as MgO, ZnO, CaCO3, and Al2O3, calcium terephthalate, calcium phosphate, etc.), thereby forming a magnetic thin film to <=1.5mum. Thus, a tape has superior running characteristics, superior stability of playback output, etc. |
