| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a fine porous film having the sufficiently excellent balance between gas permeability and heat shrinkability even when the straining rate in stretching is large, and to provide a battery separator using the same. <P>SOLUTION: The fine porous film contains a polypropylene resin composition having elongational viscosity of 18,000-40,000 Pa s and shear viscosity of 5,000-10,000 Pa s. <P>COPYRIGHT: (C)2012,JPO&INPIT |
