| 摘要 |
PURPOSE:To obtain a film providing magnetic tapes with extremely excellent output characteristics, having a small coefficient of friction to secure handling properties, having specific surface protrusions, containing a thermoplastic resin and inert particles. CONSTITUTION:A biaxially orientated film comprising a thermoplastic resin and inert particles, having average height of surface protrusion on at least one side >=1/3 average particle diameter of inert particles contained. A film having <=40% based on total number of protrusions of number of protrusions with height <=1/3 average particle diameter of inert particles contained on the surface of one side and molecular orientation from the surface to 1mum depth of biaxial orientation. Relationship among content A(wt.%) of inert articles in the film, average particle diameter D(nm) of the particles and total number N (protrusions/mm<2>) of protrusions on at least one side satisfy N/(A/D<3>)>=5X10<13>. |
