| 摘要 |
PROBLEM TO BE SOLVED: To provide a multi-layer hollow separation film suitable for a battery separation film. SOLUTION: The multi-layer fine hollow battery separation film contains a high polymer polypropylene having a melt flow index of 1.2 or less measured in a layer, a polyethylene layer and a high polymer polypropylene having a melt flow index of 1.2 or less measured in a layer to form a fine hollow battery separation film by a dry stretching method. The fine hollow battery separation film has a separation film having a thickness of 25μor less and a porosity of 37% or less while maintaining a Gurley value of 13 to 15 min. COPYRIGHT: (C)2008,JPO&INPIT |
