| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a polyolefin microporous membrane containing few obstacles therein, being excellent in quality and exhibiting favorable cycle characteristics when used as a separator for nonaqueous electrolyte secondary batteries. SOLUTION: The method for producing a polyolefin microporous membrane includes (a) a kneading step in which a polyolefin composition is kneaded, (b) a sheet forming step in which a sheet is formed from the kneaded polyolefin composition, (c) a sheet stretching step in which the formed sheet is stretched to form a stretched product, and (d) a microporous membrane forming step in which a microporous membrane is formed from the sheet or the stretched product. The polyolefin composition has an aluminum content controlled to≤20 ppm. COPYRIGHT: (C)2011,JPO&INPIT |
