| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for obtaining a retardation plate, with which proper extension temperature can be set, sufficient phase difference can be developed, and phase difference unevenness of the retardation plate is reduced even when Tg difference between resins contained in respective layers gets large or thickness of a laminate gets large, in manufacturing a retardation plate having reverse dispersibility by extending the laminate. <P>SOLUTION: The manufacturing method of the retardation plate includes: a process of obtaining the laminate containing an optical base material layer and a coating layer by applying a solution comprising a resin B and a solvent onto an optical base material containing a resin A; and a process of extending the laminate. Either of the resin A and the resin B is a resin having positive orientation birefringence and another is a resin having negative orientation birefringence. The extension is carried out by setting glass transition temperature Tg (B) of the resin B to be higher than the glass transition temperature Tg (A) of the resin A, and setting an amount of the residual solvent in the laminate to be 2 to 10 wt.%. <P>COPYRIGHT: (C)2011,JPO&INPIT |
