LAMINATED POROUS FILM, BATTERY SEPARATOR AND BATTERY

摘要

PROBLEM TO BE SOLVED: To provide a laminated porous film showing an excellent shutdown property, a low heat shrinkage rate in a high-temperature region and excellent meltdown resistance, which are required for a battery separator, and to provide a highly safe battery using this laminated porous film as a separator.SOLUTION: A laminated porous film comprises a porous layer (B) essentially comprising a polyamideimide resin formed on at least one side of a polyolefin porous film (A), provided that the heat shrinkage rate in the TD direction of the laminated porous film satisfies the relation (1): (HS)/(HS)≤1.1 (wherein HSis the heat shrinkage rate of the laminated porous film subjected to a heat-treatment at 170°C for 60 min; and HSis the heat shrinkage rate of the laminated porous film subjected to a heat-treatment at 130°C for 60 min).