| 摘要 |
PURPOSE:To improve the slipperiness, abrasion resistance, etc., of a biaxially oriented polyester film by forming dents in a specified size on the surface of the film by incorporating org. particles into the film. CONSTITUTION:A polyester (e.g. polyethylene terephthalate) is mixed with org. particles having a mean diameter of about 0.05-5mum and a relatively sharp diameter distribution (e.g. particles of a styrene/n-butyl acrylate/-divinylbenzene copolymer), formed into a film, and biaxially oriented. The resulting biaxially oriented polyester film has surface dents which are formed by the particles incorporated and have a mean diameter of 0.1-7mum a standard deviation of the mean diameter of 1-2, and an area fraction of 0.05-10%. The film is suitable as a base film of a magnetic recording medium. |
