Successively biaxial-oriented porous polypropylene film and process for production thereof
Номер патента: EP1369221A4
Опубликовано: 07-06-2006
Автор(ы): Kenichiro Nagata, Kiyoshi Sadamitsu, Koichi Ogino, Manabu Hoki, Naoki Ikeda
Принадлежит: New Japan Chemical Co Ltd
Опубликовано: 07-06-2006
Автор(ы): Kenichiro Nagata, Kiyoshi Sadamitsu, Koichi Ogino, Manabu Hoki, Naoki Ikeda
Принадлежит: New Japan Chemical Co Ltd
Реферат: 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.
Successively biaxial-oriented porous polypropylene film and process for production thereof
Номер патента: US7235203B2. Автор: Naoki Ikeda,Koichi Ogino,Kiyoshi Sadamitsu,Manabu Hoki,Kenichiro Nagata. Владелец: New Japan Chemical Co Ltd. Дата публикации: 2007-06-26.