MICROPOROUS FILM AND MANUFACTURING METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To provide a low heat shrinkage polypropylene resin-made microporous film useful as a cell separator material.SOLUTION: There are provided a microporous film consisting of polypropylene-based polymer having a melt mass flow rate (MFR, measured at 230°C and load of 21.18 N according to JIS K6758) of 1.0 to 10.0 g/10 minutes and having tensile strength in an extrusion direction (MD) of 200 MPa or more, tensile strength in a width direction (TD) of 10 MPa or more and piercing strength of 4.9 N or more and a manufacturing method therefor.SELECTED DRAWING: None