| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical film capable of obtaining a polarizing plate which ensures little light leak in a crossed Nichol state when measured not only from an orthogonal direction but also from an oblique direction, and which exhibits excellent polarizing properties, and to provide a method of manufacturing the same and the polarizing plate using the optical film. <P>SOLUTION: The optical film is made by melt extrusion of a noncrystalline thermoplastic resin and has a thickness of <100 μm and an optical axis deviation within ±10°, wherein a retardation R(0) in a normal line direction of the film is ≤10 nm, and retardations Rs(40) and Rf(40) measured from directions tilted from the normal line direction of the film toward fast axis and slow axis directions by 40° are R(0)+6 nm or lower. The resin may be a norbornene-based resin. In the method of manufacturing the optical film, when a film made of the resin extruded in a sheet form is brought into close contact with a chill roll, a temperature of the film just before its contact with the chill roll is maintained at (Tg of the resin)+50°C or higher. The polarizing plate is obtained by laying the optical film on at least one surface of a polarizer. <P>COPYRIGHT: (C)2009,JPO&INPIT |
