| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a polyvinyl alcohol-based film excellent in dimensional stability and optical properties, a polarization membrane, and a polarization plate. <P>SOLUTION: The polyvinyl alcohol-based film is produced by the casting method and has a thickness of 30-70 μm, and the dimensional change rate, which is represented by formula (1): 100×¾b-a¾/a, before and after the moisture absorption test such that after the film is left to stand in the circumstance of 23°C and an RH of 50% for 24 hours (size a), the film is left to stand in the circumstance of 23°C and an RH of 80% for 24 hours (condition A) and the film is again left to stand in the circumstance of 23°C and an RH of 50% (size b) for 24 hours, is 1% or less both in the flow direction and the width direction and the dimensional change rate in the moisture removal test such that instead of the condition A, the film is left to stand in the circumstance of 23°C and an RH of 20% for 24 hours is also 1% or less. The polarization membrane and the polarization plate are produced with the use of the film. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
