| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical film and a method for producing the optical film, in which the optical film has an excellent interlayer adhesiveness of a laminate, shows reduced retardation variation, and has excellent resistance to display unevenness and to generation of circular irregularity when the film is assembled in a liquid crystal display device, and to provide a polarizing plate and a liquid crystal display device using the optical film.SOLUTION: An optical film is to be disposed at a position opposing to a liquid crystal cell when the film is assembled to constitute a liquid crystal display device; and the optical film comprises a laminate of an acrylic layer and a cellulose acylate layer, in which an acrylic resin has a weight average molecular weight Mw of 80000 or more and a cellulose acylate resin has a total degree of substitution of acyl group of 2.0 to 3.0. The optical film satisfies all of the following conditions (A) to (C). (A) The laminate is produced by a solution cast method, and while the residual solvent amount is 1.0 to 50 mass%, the film is drawn with a draw ratio of 1.1 to 4.0 as the sum of draw ratios in a longitudinal direction and a lateral direction. (B) The optical film has Ro of less than 10 nm and Rt of less than 25 nm. (C) The retardation variation (3&sgr;) in a width direction after drawing is 5.0 or less. |
