摘要 |
<P>PROBLEM TO BE SOLVED: To provide a polyolefin microporous film which has excellent thermal shrinkage resistance, and in which the rate property of a battery can be improved when used for a battery as a separator. <P>SOLUTION: The microporous membrane includes a polyolefin resin and an inorganic particle, wherein the inorganic particle contains a zinc oxide as a principal ingredient, the average primary particle diameter of the inorganic particle is at least 5 nm and less than 40 nm, and the D50 average particle size of the inorganic particle is at least 1.5 μm and less than 9 μm. <P>COPYRIGHT: (C)2012,JPO&INPIT |