| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a laminated porous film which has a porous structure having also a communication property secured sufficiently, while holding the strength, and can exert both a shutdown characteristic and a breakdown characteristic. <P>SOLUTION: The laminated porous film is prepared by laying at least two porous layers on each other. The film includes a first layer composed of a composition which contains a mixed resin of polypropylene-series resin and resin having a crystal melting peak temperature lower than that of the polypropylene-series resin and of 100°C or above, and a second layer composed of a composition which contains resin having a crystal melting peak temperature higher than that of the polypropylene-series resin, and has β activity and/or β crystal generating power. <P>COPYRIGHT: (C)2012,JPO&INPIT |
