| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a smooth film causing neither the breakage of the film caused by fusion to a preheating roll nor a level surface defect (level unevenness) and stretch unevenness when the optical film is formed by longitudinally roll-stretching an amorphous thermoplastic resin film. <P>SOLUTION: The amorphous thermoplastic resin film is vertically stretched by a longitudinally stretching roll device including a plurality of preheating rolls including a preheating roll having a surface roughness Ra of 0.1 to 0.5μm. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
