| 摘要 |
PURPOSE:To dispense with execution of curing at high temp. and to improve the orientation characteristic and its durability by using orientation film comprising a saponified copolymer of vinyl ester with a specified content of alpha-olefin. CONSTITUTION:A saponified copolymer of vinyl ester with 5-60mol% alpha-olefin is used as orientation film. When the content of alpha-olefin is <5mol%, the orientation film has inferior continuity of the orientation characteristic due to its hygroscopic property. When the content of alpha-olefin is >60mol%, the orientation characteristic itself becomes insufficient. Accordingly, curing of the film at high temp. becomes unnecessary and the orientation characteristic and its durability are improved as well by using such orientation film as described above. |
