| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an olefinic resin microporous film roll in which the occurrence of curvature in the unwound olefinic resin microporous film, is highly suppressed.SOLUTION: An olefinic resin microporous film roll is provided, which is formed by drawing an olefinic resin film and winding the drawn olefinic resin film having a length of 400 m or more, around a core body, and which is characterized by that the difference between the maximum outer peripheral length and the minimum outer peripheral length thereof, is 3 mm or less.</p> |
