METHOD FOR MANUFACTURING RETARDATION FILM

摘要

PROBLEM TO BE SOLVED: To reduce optical defects caused by deformation near the surface of an acrylic substrate original sheet in a roll state in manufacturing a retardation film.SOLUTION: A method for manufacturing a retardation film is provided, in which the retardation film comprises an acrylic resin film substrate and an alignment film and a retardation layer laminated on the film substrate; the method includes an alignment film formation step which further includes a step of supplying the film substrate from a roll body of long sheet having a predetermined width and applying a resin composition to constitute the alignment film on one surface of the film substrate. The film substrate constituting the roll body has a coefficient of variation of 1.3% or more in thickness distribution in a width direction; and the roll body is wrapped in a moisture-proof state by a moisture-proof film having water vapor permeability of 0.1 g/(mday atm) or less at 40°C and 90% humidity until just before the alignment film formation step.