HEAT-RESISTANT SYNTHETIC RESIN MICROPOROUS FILM, METHOD FOR PRODUCING THE SAME, SEPARATOR FOR NONAQUEOUS ELECTROLYTE SECONDARY BATTERY, AND NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

摘要

PROBLEM TO BE SOLVED: To provide a heat-resistant synthetic resin microporous film excellent in both the transparency and heat resistance of ions such as lithium ions and also free from the generation of the contamination of a production line, and a method for producing the same.SOLUTION: Provided is a method for producing a heat-resistant synthetic resin microporous film, characterized in that a radical-polymerizable monomer of 5 to 25 pts.wt. including a polyfunctional acrylic monomer of three or more functions are stuck to a synthetic resin microporous film of 100 pts.wt., and thereafter, the synthetic resin microporous film is irradiated with an ionization radiation in an absorption dose of 10 to 150 kGy.