| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a laminated porous film that exhibits breakdown characteristics more excellent than a conventional polypropylene porous film, and exhibits shutdown characteristics for ensuring safety of a battery. <P>SOLUTION: A laminated porous film includes at least first to third porous layers, and has β activation force and/or β crystal generation force. The method of manufacturing the laminated porous film includes: manufacturing a laminated nonporous membrane including a first layer formed of a composition containing a crystal nucleating agent, a second layer formed of a composition having a peak value of a crystal melting temperature higher than a peak value of a crystal melting temperature of the first layer composition, and a third layer formed of a composition having a peak value of a crystal melting temperature lower than the peak value of the crystal melting temperature of the first layer composition in a polypropylene resin; and forming a porous membrane from the laminated nonporous membrane. <P>COPYRIGHT: (C)2013,JPO&INPIT |
