摘要 |
PROBLEM TO BE SOLVED: To enhance intensity retention rate with little degradation over a long period of time of a nonaqueous electrolyte battery separator by forming a heat-resistant porous layer on one or both faces of a fine porous film. SOLUTION: Of the nonaqueous electrolyte battery separator provided with a fine porous film mainly formed of thermosetting resin having a shutdown function, and a heat-resistant porous layer mainly formed of aromatic polyamide and laminated on one or both faces of the fine porous film, a terminal group density ratio of the total aromatic polyamide satisfies [COOX]/[NH<SB>2</SB>]<1, (provided, X denotes hydrogen, alkali metal, or alkaline earth metal). With the use of the separator, a nonaqueous electrolyte battery with stable discharge capacity over a long period of time can be obtained. COPYRIGHT: (C)2009,JPO&INPIT |