| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for producing a biaxial optical retardation film having a high retardation value and a uniform retardation value in the width direction. <P>SOLUTION: A substantially non-oriented film of an amorphous thermoplastic resin is stretched uniaxially while being widened to the width direction under such a condition that the inequality: 1.5Vsr≤Vsf≤5Vsr (wherein Vsf (%/minute) is the average strain rate for 5 seconds after the widening work is started; Vsr (%/minute) is the average strain rate for 5 seconds before the widening work is completed) is satisfied. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
