| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of manufacturing a retardation film by longitudinal-roll-stretching a film consisting of amorphous thermoplastic resin by which the smooth film free from the breaking or stepwise surface defects (step unevenness) of the film due to the fusion to a pre-heating roll and the stretching ununiformity can be obtained.SOLUTION: In the method of manufacturing the retardation film which is for longitudinal-roll-stretching the film consisting of the amorphous thermoplastic resin by a roll stretching device having a plurality of pre-heating rolls, the preheating roll right before the stretching in the roll stretching device has a non-adhesion treated surface, and the preheating temperature is ≥(Tg-10°C) and ≤(Tg+5°C), where Tg is the glass transition point (°C) of the thermoplastic resin. |
