| 摘要 |
PURPOSE:To obtain a biaxially oriented polyester film which has excellent flatness, chipping resistance, slittability and easy slipperiness and is adequate mainly for a magnetic recording medium base. CONSTITUTION:Spherical inert particles having a volume averaged grain size of 0.1 to 1.0mum, volume averaged grain size larger than twice the number averaged grain size, a grain size ratio (major diameter/minor diameter) of 1.0 to 1.2 and a relative standard deviation of over 0.5 are incorporated at 0.01 to 5wt.% into polyester. |
