| 摘要 |
PURPOSE:To obtain said film which has excellent abrasion-resistance, slipperiness and few drop outs and is suitable for a magnetic tape, by generating a specific state of a surface on a polyester film by incorporating lithium fluoride particles. CONSTITUTION:By making a polyester film to contain preferably lithium fluoride particles of 0.005-0.05 (wt.) % to the polyester film and preferably separating particles. (Particles containing lithium, calcium and phosphorus elements are suitable and a used amount of 0.06-0.18% to the polyester film is preferable.) An aimed film of which a number of secondary interference fringes measured by a multiple interference method is 30-300pieces/mm.<3> and 5-60% of it is due to lithium fluoride particles is obtained. |
