A METHOD OF PREPARING OPTICAL FILM

摘要

PURPOSE: A method for manufacturing an optical film is provided to prevent stripes of width direction on an optical film by using a release roll maintained at the fixed temperature. CONSTITUTION: A method for manufacturing an optical film is as follows. A dope type raw material is casted in on a supporter(10) or drum rotated by casting rolls(13,15) and a casting layer is formed. The casting layer is separated from the supporter or drum by a release roll(30) and the casting layer is transferred to a tenter(50) and dried. The side of the casting layer which is not in contact with the supporter or drum contacts the release roll and is transferred. After the casting layer is separated from the supporter or drum, the side of the casting layer which is not in contact with the supporter or drum is heated immediately before contact with the release roll so as to keep the fixed temperature.