| 摘要 |
PROBLEM TO BE SOLVED: To provide a biaxially oriented polypropylene film which is improved in strength and heat resistance in comparison with a conventional biaxially oriented polypropylene film. SOLUTION: In a method for producing the biaxially oriented propylene film, a propylene film oriented in at least one direction is further oriented biaxially at the same time, or a polypropylene film oriented uniaxially in the longitudinal direction or a biaxially oriented propylene film is further oriented biaxially at the same time. When a polypropylene film is simultaneously oriented biaxially, the film is oriented 1.5-5 times in the longitudinal direction and 0.8-10 times in the transverse direction. COPYRIGHT: (C)2009,JPO&INPIT |
