| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing an optical film which enables convenient and continuous manufacture of optical films of different film thicknesses without changing a die among those having different slit clearances and can prevent occurrence of unevenness in film thickness sufficiently over a long period even when relatively thin optical films are manufactured. <P>SOLUTION: The method of manufacturing an optical film comprises forming, on a support, a casted film by discharging a casting dope 20 from a die 2 onto a continuously running support 1 at a discharge rate of 200-720 g/m<SP POS="POST">2</SP>, evaporating the solvent from the casted film and removing the casted film as a film from the support. The casting dope 20 is prepared by mixing an initial dope 21 consisting of at least a polymer material dissolved in a solvent with a diluent dope 22 having a concentration of the polymer material lower than that of the initial dope in such a manner as to meet the relation: 20≤hd≤100 and 150≤hd÷(x/100)≤600 (wherein, hd μm, is the final film thickness of the optical film; and x, wt.%, is the concentration of the polymer material of the casting dope). <P>COPYRIGHT: (C)2012,JPO&INPIT |
