发明名称 |
SUCCESSIVELY BIAXIAL-ORIENTED POROUS POLYPROPYLENE FILM AND PROCESS FOR PRODUCTION THEREOF |
摘要 |
<p>Disclosed is a successively biaxially stretched film obtained by successive biaxial stretching method comprising extruding a melt of a beta -crystal nucleating agent-containing polypropylene-based resin composition from a T-die, cooling the extruded resin on a chill roll, and stretching the resulting web sheet longitudinally and then transversely, wherein the longitudinally stretched sheet is made to have a degree of beta -crystal orientation of less than 0.3 by the following method (I) and/or (II), optionally subjected to annealing treatment, and transversely stretched: method (I): melting the polypropylene-based resin composition containing needle crystals of a specific beta -crystal nucleating agent at a temperature not lower than m.p. of the polypropylene-based resin and lower than dissolution temperature of the beta -crystal nucleating agent in the polypropylene-based resin melt, and extruding the melt from the T-die at the same temperature, method (II): adjusting neck-in ratio during longitudinal stretching to 25 to 55%. <??>The porous polypropylene film has good breakage resistance during manufacture, excellent thickness uniformity, high porosity and air-permeability, and is useful for battery separators.</p> |
申请公布号 |
EP1369221(B1) |
申请公布日期 |
2009.11.11 |
申请号 |
EP20020712390 |
申请日期 |
2002.02.15 |
申请人 |
NEW JAPAN CHEMICAL CO.,LTD. |
发明人 |
SADAMITSU, KIYOSHI;IKEDA, NAOKI;HOKI, MANABU;NAGATA, KENICHIRO;OGINO, KOICHI |
分类号 |
B29C55/14;B29C55/00;C08J5/18;C08J9/00;H01M2/16 |
主分类号 |
B29C55/14 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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