METHOD FOR PRODUCING RETARDATION FILM

摘要

A method for producing a retardation film having specific optical characteristics from an unstretched film that is provided with a resin layer (a) formed of a resin (A) containing a polycarbonate and a resin layer (b) formed of a resin (B) having a negative intrinsic birefringence. This production method is characterized in that: the unstretched film has such properties that different phase differences arise according to the temperature thereof; this method comprises a stretching step for uniaxially stretching the unstretched film a plurality of times at different temperatures in different directions; a resin layer having a specific plane orientation coefficient is obtained by stretching the resin layer (a) by the stretching step; a resin layer having specific birefringence and Nz coefficient is obtained by stretching the resin layer (b); the resin (A) has a specific glass transition temperature (TgA); and the TgA and the glass transition temperature (TgB) of the resin (B) satisfy a specific relation.