Optical film, method of manufacture thereof and sheet polarizer

摘要

An optical film made via melt extrusion of a noncrystalline thermoplastic resin and having a thickness of below 100 mum, a residual phase difference of up to 10 nm and an optical axis deviation within ±10°, and a method for manufacture of an optical film wherein, when a nocrystalline thermoplastic resin having a glass transition temperature Tg is extruded from an extrusion die into a film and bringing the film into close contact with a chill roll, a temperature of the film before the film from the die exit is brought into close contact with the chill roll is maintained not to fall below Tg+50° C.