| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a microporous polyethylene membrane exhibiting little change in thickness and air permeability during compression and having a rapid electrolyte-absorption rate, and to provide its production method and a battery separator formed by such microporous polyethylene membrane. <P>SOLUTION: The microporous polyethylene membrane is made of a polyethylene resin comprising ≤15 mass% of ultra-high molecular weight polyethylene having a mass-average molecular weight of ≥1 x 10<SP POS="POST">6</SP>. The microporous polyethylene membrane is a single film that has a densely-structured layer comprising an average pore diameter of 0.01-0.05 μm and a coarsely-structured layer having an average pore diameter larger by 1.2-5.0 times than that of the densely-structured layer, both structured layers being adjacent to each other in a thickness direction, wherein a coarsely-structured layer is formed at least on one surface. <P>COPYRIGHT: (C)2013,JPO&INPIT |
