| 摘要 |
PURPOSE:To obtain a magnetic recording medium having excellent electromagnetic conversion characteristics by specifying the coercive force and residual magnetic flux density of a first magnetic layer (lower layer) and of a second magnetic layer (upper layer) in a multilayered structure of magnetic layer containing magnetic material and a binder. CONSTITUTION:The magnetic recording medium has a multilayered structure consisting of at least two magnetic layers containing magnetic material and a binder formed on the surface of a nonmagnetic supporting body. Coercive force of each magnetic layer is specified to 450 - 660Oe for the first magnetic layer and to 700 - 900Oe for the second magnetic layer, and the difference of coercive force for two layers is specified to 150 - 300Oe. The residual magnetic flux density is specified to >=1,900 Gauss for the first magnetic layer and to >=1,500 Gauss for the second magnetic layer, and the difference between them is specified to <=600 Gauss. Moreover, thickness of each layer is specified to between >=1.5mum and <=5mum for the first magnetic layer and to between >=1.5mum and <=3mum for the second magnetic layer, and the total thickness of magnetic layers is specified to 3 - 7mum. As for the binder, polyisocyanate is essentially used for the thermosetting type binder component. |
