| 摘要 |
PURPOSE:A polyimide film capable of forming a magnetic recording medium having high-density recordability and excellent runnability and being suitable for video magnetic tapes or the like, having an average surface roughness and a coefficient of friction each having a specified value and an initial modulus of a specified value. CONSTITUTION:A film comprising a polyimide resin having at least 80wt% repeating units of the formula (wherein R<1> is a tetravalent aromatic organic group, and R<2> is a bivalent aromatic organic group), which is used for recording magnetic media, and which has a surface roughness <=0.01mu, a coefficient of friction <=1.5, and an initial modulus >=400kg/mm.<2>. By using a polyimide film which can meet the above requirements, it is possible to prepare a magnetic recording medium having high-density recordability and excellent runnability, suited as a video magnetic tape, floppy disk or the like. |
