| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method for a polyester film for a magnetic recording medium, by which a tape for DVC nearly free from DO and having high quality can be stably manufactured without quality difference in a film manufacturing lot and between film manufacturing lots. SOLUTION: In the manufacturing method for the polyester film for the magnetic recording medium, wherein after an aqueous solution containing a water soluble polymer, minute particles and silicone as main components is applied on the surface of a film stretched in one direction, the film is dried, stretched and heat treated, the aqueous solution is applied by using a metering bar having 2.0-8.0μm average value in the width direction and <=0.4μm difference between the maximum value and the minimum value in the width direction of Ra at the surface part in contact with the film of the metering bar. The average value in the width direction of Ra at the surface part in contact with the film of the metering bar and the concentration of the aqueous solution are controlled so that the changing ratio of the product thereof is in the range within±5%, when the metering bar is exchanged for another and the concentration of the aqueous solution is changed. |
