| 摘要 |
PROBLEM TO BE SOLVED: To obtain the subject film giving magnetic recording media having specific physical properties in terms of on % thermal shrinkage, ten point- average roughness little curling and excellent flatness. SOLUTION: This film having a thermal shrinkage of 0.05-2%, preferably 0.1-1%, in the MD direction at 200 deg.C, a ten point-average roughness Rz of 10-200 nm on the surface of the side opposite to the side to dispose a magnetic layer thereon, an X/Y ratio of 0.5-0.9. preferably 0.6-0.8, wherein X is a F-1 value in the MD direction and Y is a F-1 value in the TD direction, and preferably containing >=50 mol.% especially >=70 mol.% of repeating units of formula I and/or formula II (Ar1 -Ar3 are each a group of formula III, a group of formula IV, etc.) is obtained. A magnetic layer is disposed on one surface of the film to obtain a magnetic recording medium. |
