| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for producing an optical film by a melt casting film-forming process, by which an optical film excellent in uniformity of retardation and appearance quality can be produced by pinching an extruded film melt with uniform pressure while preventing scratches. <P>SOLUTION: This method for producing an optical film comprises the steps of extruding a melt comprising a thermoplastic resin through a casting die into a film shape; pinching the extruded film melt between a main roller and a touch roller; and thereafter cooling to be solidified. The film melt is extruded such that, when a non-pinched film is obtained by cooling the extruded film melt without pinching, the thickness of an area of the non-pinched film corresponding to the pinched area pinched in the pinching step becomes maximum at the center in width direction and minimum at the end parts of the area corresponding to the pinched area. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
