| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a retardation film manufacturing method capable of obtaining retardation films with the same wavelength dispersibility and different phase difference from one type of raw roll film. <P>SOLUTION: The method comprises the steps of: stretching a belt shaped resin film used as a raw roll film using a stretching device to obtain a retardation film; and stretching the raw roll film using the stretching device at a stretching temperature different from that of the former step without exchange of the raw roll film in the stretching device to obtain a retardation film having the different value of phase difference and the same wavelength dispersibility of phase difference compared with the former retardation film. The resin film used as the raw roll film is a laminated film having a resin layer A consisting of a resin (A) with positive intrinsic birefringence, and a resin layer B consisting of a resin (B) with negative intrinsic birefringence. A glass transition temperature difference ΔTg between the resin (A) and the resin (B) is less than 5°C. <P>COPYRIGHT: (C)2012,JPO&INPIT |
