| 摘要 |
The purpose of the present invention is to provide: a polyolefin microporous film having excellent productivity, which is capable of maintaining good film flatness even in the state of a wide and long roll; a polyolefin microporous film roll; a method for producing the polyolefin microporous film or the polyolefin microporous film roll; and a separator for batteries, which uses the polyolefin microporous film or the polyolefin microporous film roll. The present invention provides: a polyolefin microporous film which has a thickness of from 1 mum to 50 mum (inclusive), an air permeation resistance of from 50 seconds/100 mL to 500 seconds/100 mL (inclusive), and a shrinkage in the width direction of from -0.3% to 0.3% (inclusive) and a shrinkage in the longitudinal direction of from 0.0% to 1.5% (inclusive) at 40°C in 48 hours; a film roll which is obtained by winding up the polyolefin microporous film; a method for producing the polyolefin microporous film or the polyolefin microporous film roll; and a separator for batteries, which uses the polyolefin microporous film or the polyolefin microporous film roll. |
