| 摘要 |
PURPOSE:To improve the mechanical and electrical characteristics of a magnetic recording medium by incorporating plural kinds of magnetic powders different from each other in coercive force and particle size into the magnetic layer while continuously varying the concn. distributions in the thickness direction of the magnetic layer. CONSTITUTION:Magnetic powder having high coercive force and small particle size and magnetic powder having low coercive force and large particle size are prepd. so as to regulate the difference in coercive force to >=150 Oe and that in particle size to >=50%. When the magnetic powders are incorporated into a magnetic layer on a substrate, the concn. of the former powder is made max. in the surface of the magnetic layer and is continuously reduced toward the interior and the concn. of the latter powder is made max. at the interface between the magnetic layer and the substrate and is continuously reduced toward the surface of the magnetic layer. The magnetic powders may be powders of an oxide such as gamma-Fe2O3 or barrium ferrite, a metal such as Fe or Co and a nonoxide such as iron nitride or iron carbide. |
