| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an optical film which is free from occurrence of peeling unevenness in the film width direction produced upon roll vertical stretching regarding a process for subsequently producing biaxially stretched film for optical use. <P>SOLUTION: The method for producing a film is used when a film 5 made of a thermoplastic resin is subjected to roll vertical stretching by two stretching rolls 1, 2 arranged at intervals. Nip rolls 3, 4 are arranged in such a manner that a holding part 6 is made into the edge part on the side of the stretching roll 2 in a contact region 8, and further, a holding part 7 is made into the edge part on the side of the stretching roll 1 in a contact region 9. In this way, the roll vertical stretching is performed in such a manner that the contact time t between the film and the stretching roll 1 when the film 5 is stretched satisfies 0.5s<t<2.5s, and also, the surface temperature T of the stretching roll 1 satisfies the film Tg-6°C<T<the film Tg. <P>COPYRIGHT: (C)2012,JPO&INPIT |
