| abstract |
To obtain a TAC film excellent in optical isotropy. A cast film is formed by casting a dope containing TAC on a casting band. After the cast film has a self-supporting property, it is peeled off as the wet film 46. The wet film 46 is fed into the tenter dryer 60. Preheating is performed at the inlet portion 80 and stretching is performed at the stretching portion 81. After the film width is shrunk by the relaxing part 82, the film is sent out as the film 61 after passing through the outlet part 83. When the biting width is L1 (mm), the maximum extension width is L2 (mm), and the separation width is L3 (mm), 1 <(L2-L3) / L1 × 100 <15. In the film 61, the occurrence of bowing is suppressed. [Selection] Figure 2 |