| 摘要 |
PURPOSE:To improve durability by incorporating granular nonmagnetic powder and lubricating agent at specific ratios to planar hexagonal ferrite particles into a magnetic layer. CONSTITUTION:The granular nonmagnetic powder and further the lubricating agent are incorporated at the ratio of 0.1-30pts.wt. per 100pts.wt. planar hexagonal ferrite particles into the magnetic layer of a magnetic recording medium formed with the magnetic layer contg. the magnetic powder essentially consisting of the planar hexagonal ferrite particles and binder on a nonmagnetic base. The Vickers hardness of the planar hexagonal ferrite particles is generally about 1,000-3,500kg/mm<2> and therefore, the granular nonmagnetic powder is exemplified by the powder having the hardness higher than said particles, for example, powder consisting of granular particles of alpha-Al2O3, Cr2O3, etc. The lubricating agent is used at about 2-25pts.wt. per 100pts.wt. magnetic powder essentially consisting of the planar hexagonal ferrite particles. The recording medium having the excellent durability and a long life is thus obtd. |
