HEAT RESISTANT SYNTHETIC RESIN MICROPOROUS FILM, METHOD FOR MANUFACTURING SAME, NONAQUEOUS ELECTROLYTE SECONDARY CELL SEPARATOR, AND NONAQUEOUS ELECTROLYTE SECONDARY CELL

摘要

The present invention provides a heat resistant synthetic resin microporous film that has improved heat resistance while reducing a decline in mechanical strength, and a method for manufacturing the same. This heat resistant synthetic resin microporous film is characterized in having: a synthetic resin microporous film that contains a synthetic resin; and a film layer that is formed on at least a portion of the surface of the synthetic resin microporous film, the film layer containing a polymer of a polymerizable compound that has a bifunctional or higher-functional radical-polymerizable functional group; the surface porosity being 30-55%, the air permeability being 50-600 sec/100 mL, the maximum thermal shrinkage being 20% or lower when heating is carried out from 25-180˚C at a temperature-elevating rate of 5˚C/min, and the piercing strength being at 0.7 N or higher.