| 摘要 |
PROBLEM TO BE SOLVED: To provide a porous film roll, free from the occurrence of wrinkle in the longitudinal direction and in the width direction and free from the occurrence of the wrinkle with time.SOLUTION: A porous film roll is formed by winding a porous film on a winding core and has hardness of ≤95 in all measuring points when the hardness is measured at 20°C and 65% RH with 10 mm interval in the width direction over the overall width. |
