| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a porous polyolefin film which exerts excellent safety, output characteristics and long-term reliability when used as a separator. <P>SOLUTION: The porous polyolefin film has a width-directional heat shrinkage ratio at 120°C for 1 hour of 0-3.5%, and a thickness directional penetration time of ionic liquid T1 (sec.) of 10-300 seconds, and satisfies T1/T2>1.3, wherein T2 is the thickness-direcitonal penetration time of ionic liquid after being made into an electret by DC corona discharge. <P>COPYRIGHT: (C)2013,JPO&INPIT |
