COMPOSITE POROUS FILM AND METHOD FOR MANUFACTURING SAME

摘要

A composite porous membrane used as a separator for a battery includes a porous membrane A made of a polyolefin resin and a porous membrane B containing a heat-resistant resin laminated thereto, wherein the surface of the porous membrane B on the side that does not face the porous A has a three-dimensional network structure having nodes, and the peeling interface on the side of the porous membrane B formed when the porous membrane A and the porous membrane B are peeled off has a membrane morphology having pores with a pore size of 50 to 500 nm in an amount of at least 100 pores/10 mum2.