COMPOSITE POROUS MEMBRANE AND METHOD FOR PRODUCING SAME

摘要

Provided is a composite porous membrane that achieves both superior adhesion of a heat-resistant resin layer and a low amount of air permeation resistance increase, even if the composite porous membrane, such as a battery separator, is made much thinner in the future. In the composite porous membrane used as a battery separator, a porous membrane (B) containing a polyamide resin containing an isophorone structure at an amine component is layered on a porous membrane (A) comprising a polyolefin resin. In that wherein porous membrane A falls within a particular range of thicknesses, average pore sizes, and porosities and the composite porous membrane as a whole falls within a particular range of thicknesses, the composite porous membrane is characterized by further falling within a particular range of delamination strengths at the interface between porous membrane A and porous membrane B, and a particular range of differences between the air permeation resistance of porous membrane A and the air permeation resistance of the composite porous membrane as a whole.