LAMINATED POROUS FILM AND PRODUCTION METHOD THEREFOR

摘要

The purpose of the present invention is to provide a heat-resistant laminated porous film having no risk of losing battery characteristics when used as a separator for lithium secondary batteries. This laminated porous film has a porous layer comprising an imide-based polymer, formed on one surface or both surfaces of a porous layer comprising polyolefin, and is characterized by having the following characteristics: 1) the air permeability having a Gurley number, on the basis of JIS P8117, of 10 s/100 cc-1,000 s/100 cc; 2) having no residual alcohol-based solvent in the porous layer comprising the imide-based polymer; and 3) the thickness of the porous layer comprising the imide-based polymer being 1-20 µm.