RETARDATION FILM AND METHOD FOR PRODUCTION THEREOF

摘要

Disclosed is a method for production of a retardation film made of a polypropylene resin. The method comprises subjecting a film made of a polypropylene resin to the stretching in the machine direction and the stretching in the transverse direction successively, wherein the stretching in the transverse direction comprises the following steps: preheating the film at a preheating temperature higher than the melting point of the polypropylene resin; stretching the preheated film in the transverse direction at a stretching temperature lower than the preheating temperature; and thermofixing the transversally stretched film. Also disclosed is a retardation film made of a polypropylene resin, which has a high axis accuracy and a uniform phase difference. The retardation film can be produced by the method.