POROUS MEMBRANE AND PROCESS FOR PREPARING THE SAME

摘要

The present invention pertains to a microporous film formed from cellulose fibres, the cellulose fibres of the microporous film being obtained from a mixture which is more than 50 wt% (1) first raw-material cellulose fibres having a surface area of 250m2/g-500m2/g, measured by means of Congo red dye, and less than 50 wt% (2) second raw-material cellulose fibres having a surface area of 150m2/g-250m2/g, measured by means of Congo red dye. The microporous film enables the low-cost provision of a separator, for an electrochemical element, having excellent properties.