LAMINATE POROUS FILM AND SEPARATOR FOR CELL

摘要

PROBLEM TO BE SOLVED: To provide a laminate porous film which has a porous structure securing sufficient communicating properties while retaining strength and can exert breakdown characteristics superior to those of conventional polypropylene porous films. SOLUTION: The laminate porous film comprises at least two porous layers laminated. One of the porous layers contains a polypropylene type resin, and the other is a heat-resistant layer composed of a resin composition having a crystal melting peak temperature higher than that of the resin composition of the layer containing the polypropylene type resin. The film has aβactivity and/orβcrystal forming properties. COPYRIGHT: (C)2009,JPO&INPIT