| 摘要 |
PROBLEM TO BE SOLVED: To provide an optimum biaxially oriented thermoplastic resin film as a base film for a magnetically recording medium wherein electromagnetic conversion characteristics can be improved without deteriorating durability of a magnetic surface. SOLUTION: In a biaxially oriented thermoplastic resin film wherein a film having a thermoplastic resin A and a particle as main constituents is laminated on at least one side of a film having a thermoplastic resin B as a main constituent, a thickness of the laminated film of the thermoplastic resin A is 0.005-3μm, and the average particle size of particles contained in the laminated film is 0.1-10 times the thickness of the laminated film. A content of the particle in the laminated film is under 0.5wt.%, and a thermal shrinkage coefficient in a longitudinal direction is 0.1-5% under conditions at 100 deg.C for 30min. |
