Title:
二軸配向ポリプロピレンフィルムの製造方法
Document Type and Number:
Japanese Patent JP7405099
Kind Code:
B2
Abstract:
Provided is a biaxially oriented polypropylene film which has high rigidity, has excellent heat resistance even at the high temperature of 150˚C, can easily retain a bag shape when used as a packaging bag, and exhibits few wrinkles in seal parts when heat sealing has been performed thereon. Also provided is a method for manufacturing the biaxially oriented polypropylene film comprising, in the following order: a step in which an unstretched sheet is obtained by extruding a polypropylene resin composition containing a polypropylene resin with a meso pentad fraction of at least 97.0%; a step in which the unstretched sheet is stretched in the length direction thereof; a preheating step in which the length-direction stretched sheet is heated to a preheating temperature of at least Tm and not higher than Tm+25˚C; a step in which the preheated length-direction stretched sheet is stretched in the width direction at a temperature of at least Tm-10˚C and not higher than the preheating temperature; a step in which the sheet is stretched in the width direction at a temperature of at least Tm-70˚C and not higher than Tm-5˚C, and lower than the temperature of the step in which the sheet is stretched in the width direction at a temperature of at least Tm-10˚C and not higher than the preheating temperature; and a heat treatment step.
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Inventors:
Koji Yamada
Horinouchi Kazuhito
Mayo Nakano
Toru Imai
Horinouchi Kazuhito
Mayo Nakano
Toru Imai
Application Number:
JP2020563162A
Publication Date:
December 26, 2023
Filing Date:
December 19, 2019
Export Citation:
Assignee:
Toyobo Co., Ltd.
International Classes:
B29C55/14; C08J5/18
Domestic Patent References:
| JP2017500226A | ||||
| JP2018130958A | ||||
| JP2016188361A | ||||
| JP2006117956A |
Foreign References:
| WO2014104089A1 |