Abstract: The problem of the present invention is to provide a phase difference film, by utilizing a cellulose ester having an acyl group substitution degree of less than 2.0 and improved compatibility, having high phase difference property despite its small film thickness and imparting high contrast and optical transmittance to a liquid crystal display device. A polarizing plate and a liquid crystal display device provided with the phase difference film are also provided. The phase difference film of the invention contains a cellulose ester which is obtained by substituting an acyl group having at least two carbon atoms for a hydroxy group in a glucose unit composing a cellulose, the film satisfies specific expressions when DS2, DS3 and DS6 are degrees of substitution of the acyl groups for the hydroxy groups at a 2C, 3C and 6C positions, respectively, of the glucose unit.

Abstract: 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 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 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 80° C. and 90% RH of ?0.5 to 0.5%.

Abstract: The problem of the present invention is to provide a phase difference film, by utilizing a cellulose ester having an acyl group substitution degree of less than 2.0 and improved compatibility, having high phase difference property despite its small film thickness and imparting high contrast and optical transmittance to a liquid crystal display device. A polarizing plate and a liquid crystal display device provided with the phase difference film are also provided. The phase difference film of the invention contains a cellulose ester which is obtained by substituting an acyl group having at least two carbon atoms for a hydroxy group in a glucose unit composing a cellulose, the film satisfies specific expressions when DS2, DS3 and DS6 are degrees of substitution of the acyl groups for the hydroxy groups at a 2C, 3C and 6C positions, respectively, of the glucose unit.

Abstract: The purpose of the present invention is to provide a polarizing plate protective film and liquid crystal display device comprising same whereby the generation of egg-shaped blur in a liquid crystal display device (especially an IPS liquid crystal display device) can still be limited even under high-temperature/high-humidity conditions. For this polarizing plate protective film, if nx is the refractive index in the X-axis direction at which the birefringence in the film surface reaches a maximum and ny is the refractive index in the Y-axis direction orthogonal to the X-axis direction in the film surface, then the birefringence under stress (nx?ny) of the film as measured at a wavelength of 589 nm when any tensile stress 5-35 MPa is applied in the X-axis direction or Y-axis direction of the film under 50 DEG C, 80% RH conditions is 0.