| 摘要 |
PURPOSE:To provide a process for continuous production of the phase difference film having small dependency of retardation on angle. CONSTITUTION:A stretched thermoplastic resin film or sheet is continuously supplied to a heating zone in parallel with a stretching direction and while a pressure is impress to the film or sheet surface, the film or sheet is heated to the glass transition temp. of the resin or above in a heating zone, by which the sheet is continuously thermally relieved while the elongation in parallel with the film surface or sheet surface and in the direction perpendicular to the stretching axis is suppressed during the passage through the heating zone, by which the phase difference film having the small dependency of the retardation on the angles is obtd.
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