| 摘要 |
PURPOSE:To offer a magnetic recording medium whose video characteristic is excellent and whose durability and running property are good by consituting so that a specific surface area of a ferromagnetic metallic powder is large, a surface roughness of a magnetic layer is small, and also a coefficient of friction of the surface of the magnetic layer and the back layer is small. CONSTITUTION:The surface of a magnetic layer is smoothed and a noise is lowered by constituting so that a specific surface area of a ferromagnetic metallic powder measured by an N2 gas adsorbing method by a BET system becomes >=35m<2>/gr. Also, in order to minimize a spacing loss, and in order to lower a noise, a surface roughness of the magnetic layer is set to <=0.04mu. In this regard, its surface roughness is a surface roughness measured by an average roughness of a center line of 0.25mm. cut-off value defined in the clause 5 of JIS-B0601. Also, durability in case the magnetic layer has been smoothed has a correlation to a coefficient of friction of a medium, and the durability and the running property are raised by setting the coefficients of friction of the surface of the magnetic layer and the back layer to <=0.25 and <=0.20, respectively. |
