| 摘要 |
PURPOSE:To obtain a medium excellent in friction resistance, magnetic characteristics and durability by specifying the surface roughness of a magnetic layer essentially comprising ferromagnetic powder and specifying the amt. of lubricant incorporated into the magnetic layer. CONSTITUTION:The magnetic layer essentially comprises ferromagnetic powder and containing a nonmagnetic binder and lubricant. Surface roughness of the magnetic layer is specified to 0.006 - 0.010mum when measured with a tracer-type roughness meter inder conditions of 2mum stylus diameter, 25 mg load on the tracer, 0.008 mm cut-off, and 0.03 mm/sec scanning speed. The amt. of lubricant incorporated into the magnetic layer is specified to 400 - 650 mg/m<2>. By specify ing the surface roughness, increase in the coeff. of friction and in the torque loaded on a motor can be suppressed and deterioration of magnetic characteristics can be prevented. Moreover, by specifying the amt. of lubricant, reduction of durability and increase in the coefft. of friction and in the torque can be prevent. |
