| 摘要 |
PURPOSE:To provide the polyester film which is excellent in heat resistance, bondability, slip property, etc., and is particularly useful in a packaging material, magnetic tape, magnetic disk, magnetic card, printing material, etc. CONSTITUTION:A polyester having a secondary transition point of 50 deg.C or higher and containing dicarboxylic acid units at least 1mol% of which are phenylindanedicarboxylic acid units, is thoroughly mixed with fine particles having an average particle diameter of 0.002-5mum. The mixture is formed into a film and biaxially stretched in an areal stretch ratio of 1.5-25. |
