| 摘要 |
PROBLEM TO BE SOLVED: To prepare a film satisfying necessary requirements for stable coating without developing wrinkles. SOLUTION: This film has a heat shrinkage of not more than 0.5%, an elastic modulus is the longitudinal direction of not less than 700kg/mm<2> , an elastic modulus is the widthwise direction of not less than 900kg/mm<2> , and an average thickness of not more than 6μm, moreover, the ratio of elastic modulus in the longitudinal direction to that in the widthwise direction is 1.1-1.8, the P-V value of thickness variation of the cycle not more than 50mm in the longitudinal direction of the film is not more than 7% of the average thickness, the P-V value of thickness variations of the cycle not more than 40mm in the widthwise direction of the film is not more than 7% of the average thickness, and the thickness variation in the directions of length and width in total is not more than 10% of the average film thickness. |
