| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for efficiently obtaining a wrinkle-free, wide and long oriented film having an average Nz coefficient of greater than 0 and less than 1 as an elemental film. SOLUTION: In an process for obtaining an oriented film by stretching a long film in a direction having a slanting angle to the width direction, the long oriented film is obtained by maintaining running rates of both the ends of the film almost equal and constant through the process, the long oriented film having an average Nz coefficient expressed by (n<SB>x</SB>-n<SB>z</SB>)/(n<SB>x</SB>-n<SB>y</SB>) of greater than 0 and less than 1 where n<SB>x</SB>is an average value in the film width direction of refractive indices in the direction of a retarding phase axis in the film plane, n<SB>y</SB>is an average value in the film width direction of refractive indices in the direction of an advancing phase axis in the film plane, and n<SB>z</SB>is an average value in the film width direction of refractive indices in the direction of a film thickness direction. COPYRIGHT: (C)2007,JPO&INPIT
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