| 摘要 |
PURPOSE:To obtain film excellent in flat smoothness, multi-turn running property, wear resistance and resistance to scratching by a method wherein the refractive index in the direction of the thickness of film is set to exceed a certain value and the number of concavo-convex pairs per unit film surface area satisfies the formula (1) and a certain amount of external inactive particles consisting of specified calcium oxide or inorganic salt are contained in the film. CONSTITUTION:The refractive index in the direction of the thickness of film must preferably be 1.493 or more. The number A (pairs/mm<2>) of concavo-convex pairs, each of which consists of a projection and the recess having said projection as its nucleus and the major axis of at least 0.5mum, per unit film surface area or 1mm<2> must satisfy the formula (1). In addition, the film contains 0.01-1.0wt% of internal particles containing lithium, calcium and phosphorous elements and 0.001-0.7wt% of external inactive particles consisting of calcium oxide with mean particle diameter of 0.1-10.0mum or inorganic salt. |
