| 摘要 |
PROBLEM TO BE SOLVED: To obtain a porous film excellent even in a piercing strength while maintaining high gas permeability and uniformity. SOLUTION: The porous film comprises an ethylenic polymer (A1) having 3.5-35 dl/g intrinsic viscosity [η] measured in decaline at 135°C, and is characterized with (i) 25-80% porosity, (ii) 5-80 sec/100 cc/μm gas permeability resistance, (iii)≥50 gf/μm piercing strength and (iv) <1.5 times film thickness to the average film thickness. COPYRIGHT: (C)2011,JPO&INPIT |
