| abstract |
PROBLEM TO BE SOLVED: To combine a porous resin membrane having different melting points (or softening points) without using a thermocompression bonding method or a method of directly applying a solution to a base material, thereby providing excellent ion permeability and low pores. Provided is a composite porous membrane suitable for a battery separator having both a clogging temperature and a high membrane breaking temperature. A composite porous membrane in which a porous membrane A made of a resin having a melting point of 150 ° C. or less and a porous membrane B made of a resin having a glass transition temperature higher than 150 ° C. are integrated, and the porous membrane The present invention relates to a composite porous membrane characterized in that both the front side surface of B and the surface of the porous membrane B on the interface side with the porous membrane A have a three-dimensional network structure. [Selection] Figure 2 |