| 摘要 |
<p>PURPOSE:To obtain a laminated porous film having a fine uniform pore size, having a proper non-perforation start temp. and a high nonperforation keeping temp., wide in a non-perforation keeping temp. region, high in peel strength and capable of improving the defect of a conventional laminated porous film. CONSTITUTION:A laminated film consisting of three or more layers wherein polypropylene and polyethylene are alternately laminated is stretched and perforated to obtain a laminated porous film.</p> |
