PROCESS FOR PRODUCING OPTICAL FILM AND OPTICAL FILM

摘要

Provided are: a process for producing an optical film through successive biaxial stretching in which a thermoplastic resin film is stretched in the machine direction and then stretched in the transverse direction; and an optical film produced by the process. The optical film is reduced in bowing and thickness unevenness and has satisfactory optical properties. The process for optical-film production comprises a machine-direction stretching step in which a continuous thermoplastic resin film is stretched in the lengthwise direction and a transverse-direction stretching step in which the film is subsequently stretched in the width direction. The process is characterized in that when the thermoplastic resin film is stretched in the lengthwise direction in the machine-direction stretching step, both edges of the thermoplastic resin film have a higher temperature than a central part thereof.