| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a nonaqueous secondary battery separator excellent in ionic conductivity and impregnation property to electrolyte as well as shutdown property and heat resistance thereto. <P>SOLUTION: A nonaqueous secondary battery separator includes a polyolefin microporous film and a heat resistance porous layer provided on one surface or both surfaces of the polyolefin microporous film and containing heat resistance resin. A pore diameter obtained from a specific surface area measured by BET method is represented as d<SB POS="POST">BET</SB>, and a pore diameter measured by a bubble point method is represented as d<SB POS="POST">BUBBLE</SB>. In the nonaqueous secondary battery separator, the pore diameter d<SB POS="POST">BET</SB>is in a range from 30 to 200 nm, and a ratio d<SB POS="POST">BET</SB>/d<SB POS="POST">BUBBLE</SB>satisfies the following equation (1): 1.0<d<SB POS="POST">BET</SB>/d<SB POS="POST">BUBBLE</SB>≤4.0 (1). <P>COPYRIGHT: (C)2012,JPO&INPIT |
