| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for continuously producing thermoplastic resin films by melt extrusion having a small plane birefringence index or having a small optical phase difference which has not been attained by conventional technique, and also to provide a substrate for a display element using the thermoplastic resin film produced by this production method. SOLUTION: In the film production method by which the thermoplastic resin is cooled and solidified after being melt and extruded, both ends of the film are to be raised higher than its center portion at the time when the thermoplastic resin is cooled and solidified. |
