| 摘要 |
PROBLEM TO BE SOLVED: To provide a polyvinyl alcohol film for producing a polarizing film having excellent inplane uniformity of polarizing performances (polarization degree and transmittance of a simple substance) corresponding to enlargement of area and improvement of definition; and to provide a method for producing the film. SOLUTION: The polyvinyl alcohol film has≤20 nm long period and≤15 nm thickness of an amorphous part, measured by small angle X-ray scattering, and 30-70μm thickness of the film. The polyvinyl alcohol film is produced by (α) a step for cooling the formed polyvinyl alcohol film, and (β) a step for heat-treating the cooled film, consisting of (β<SB>1</SB>) the first heat-treating step for heat-treating the film at <100°C by using a floating method, and (β<SB>2</SB>) the second heat-treating step for heat-treating the film at≥100°C by using a floating method. COPYRIGHT: (C)2006,JPO&NCIPI |
