POROUS FILM HAVING REACTIVE POLYMER LAYER THEREON FOR USE IN BATTERY SEPARATOR, AND USE OF THE POROUS FILM

摘要

Disclosed is a porous film having a reactive polymer layer thereon for use in a battery separator. The porous film comprises: a porous base film; and a reactive polymer layer which is arranged on the porous base film, which is produced by the crosslinking reaction between a cross-linkable polymer having a group reactive with an isocyanate group and a cation-polymerizable functional group in its molecule and a polyfunctional isocyanate, and which has a thickness of 2 µm or less. The reactive polymer layer has two or more through-pores having an average pore size of 5 µm or less.