Reactive polymer-carrying porous film and process for producing the same

摘要

A reactive polymer-supported porous film for a battery separator containing a substrate porous film of a porous film and a reactive polymer supported on the substrate porous film. The porous film has a temperature of 200° C. or more, at which a thickness of the porous film is reduced to ½ of a thickness when a probe is placed on the porous film. The reactive polymer is obtainable by partially crosslinking a crosslinkable polymer and a polyfunctional isocyanate. The crosslinkable polymer is obtainable by copolymerizing a crosslinkable monomer having in a molecule at least one reactive group selected from a 3-oxetanyl group and an epoxy group and a crosslinkable monomer having a reactive group capable of reacting with an isocyanate group.