POROUS POLYOLEFIN FILM, BATTERY SEPARATOR OBTAINED USING SAME, AND PROCESSES FOR PRODUCING THESE

摘要

A polyolefin porous membrane comprising protrusions of polyolefin having a size (W) within a range of 5 µm ‰¤ W ‰¤ 50 µm and a height (H) within a range of 0.5 µm ‰¤ H, and randomly disposed on one side of the polyolefin porous membrane in density not less than 3 /cm 2 and not more than 200 /cm 2 , the polyolefin porous membrane having a thickness of not more than 20 µm. Considering that battery separators will require further thinner materials and lower costs in the future, a battery separator, in which a polyolefin porous membrane with exceptionally high peel strength against a modified porous layer, suitable for high-speed processing during slit process and battery assembly process, and suitable for laminating on a modified porous layer, and a modified porous layer are laminated, is provided.