Patent attributes
A method produces a composite porous membrane including a porous membrane A formed of a polyolefin-based resin; and a porous membrane B containing a heat-resistant resin and laminated on the porous membrane A, including: (i) applying a heat-resistant resin solution onto a base film, followed by passing the coated film through a low-humidity zone, and then through a high-humidity zone to form a heat-resistant resin membrane on the base film; and (ii) bonding together the heat-resistant resin membrane formed in step (i) and a porous membrane A formed of a polyolefin-based resin, followed by converting the heat-resistant resin membrane into a porous membrane B by immersion in a solidification bath, and washing and drying the same to obtain the composite porous membrane.
