| 摘要 |
PURPOSE:To obtain a magnetic recording medium having high reliability even under high-temperature and high-humidity conditions by using a laminated film containing an oriented film of a styrene polymer having a syndiotactic structure and specified physical property values as a base film. CONSTITUTION:A single-layer film of an oriented film of a styrene polymer (especially with a residual Al component <=3000ppm, a residual Ti component <=10ppm and a residual styrene monomer <=7000ppm) having a syndiotactic structure or a laminated film containing the oriented film is used as a base film. This base film should have a coefficient of linear expansion <=5X10<-5>/ deg.C, desirably <=4X10<-5>/ deg.C, a coefficient of static friction mus of 0.3-1.0, desirably 0.3-0.9 (especially desirably in the range of the coefficient of static friction of the surface opposite to the layer on which a magnetic layer is formed), a surface roughness Ra of 0.001.0.05mum, most suitably 0.001-0.04mum and a coefficient of humidity linear expansion of 5X10<-5>/%RH. A magnetic layer is formed on at least either surface of this film to obtain a magnetic recording medium. |
