| 摘要 |
PURPOSE:To obtain a coating type magnetic recording medium of high performance, by using fine magnetic powder whose main component is metal Co in the form of hexagonal plate belonging to a closest packed hexagonal system, the main diameter and the thickness of the plate having respective specified values. CONSTITUTION:A closest packed hexagonal system is decisively necessary for the crystal system of metal Co to be used. As to the grain form, a hexagonal planar shape is most desirable in practice in order to make best use of perpendicular magnetic characteristics. As to the grain size, the main diameter and the main thickness are chosen in the range of 0.02-0.5mu and 0.005-0.1mu, respectively. As to metal component other than Co, a secondary component capable of coexisting is Fe and Ni which are easily used to control magnetic characteristics. Magnetic raw powder with characteristics of coercive force of 500-1400Oe and saturation magnetization of 100-160esu/gr is used together with vinyl chloride-vinyl acetate resin and the like and organic solvent to make coating material. By applying it to a non-magnetic substrate, a magnetic recording medium is obtained which has a magnetic layer with high residual magnetic flux density and high rectangularity ratio in the perpendicular direction. |
