| abstract |
The present invention is a microporous membrane comprising cellulose fibers, wherein the cellulose fibers are (1) a first raw material cellulose fiber having a surface area measured by Congo red dyeing of more than 50% by weight in a range of 250 m 2 / g to 500 m 2 / g, and Less than 50% by weight (2) A microporous membrane obtained from a mixture of second raw material cellulose fibers having a surface area measured by Congo red dyeing in a range of 150 m 2 / g or more and less than 250 m 2 / g. With the microporous membrane of the present invention, a separator for an electrochemical device having excellent characteristics can be provided at low cost. |