RETARDATION FILM, PROCESS FOR PRODUCING POLARIZER, AND LIQUID-CRYSTAL DISPLAY DEVICE

摘要

The purpose of the present invention is to provide a retardation film which includes cellulose acetate having a low degree of acyl substitution and, despite this, swells very little when immersed in a saponifying solution and which has satisfactory adhesion to polarizing elements. This retardation film comprises: a cellulose ester which has a total degree of substitution with acyl groups of 2.0-2.55 and in which when the common logarithm of the absolute molecular weight Mw(a), log[Mw(a)], obtained through analyses by gel permeation chromatography (GPC), low angle laser light scattering (LALLS), and viscosity measurement, is plotted as abscissa and the common logarithm of the intrinsic viscosity Iv(a), log[Iv(a)], obtained through the analyses is plotted as ordinate, the plot has a slope of 0.65-0.85; and a glass-transition-temperature lowering agent having an SP value of 9.0-11.0. The retardation film contains a solvent remaining therein in an amount of 700-3,000 mass ppm and has a change in weight through storage at 80ºC and 90% RH of -0.5 to 0.5%.