Optical laminate, optical element and liquid crystal display device

摘要

An optical laminate having layer A having a resin having a negative intrinsic birefringence and at least one layer B having a transparent resin, having substantially no orientation and laminated at least on one face of layer A and satisfies a relation |Re(A)|>|Re(B)|, wherein Re(A) and Re(B) represent in-plane retardations of layer A and layer B, respectively, measured with light having a wavelength of 400 to 700 nm, an optical element having a laminate of the optical laminate and a polarizer plate, and a liquid crystal display device using at least one sheet of the optical laminate. In the liquid crystal display device, optical compensation can be made in accordance with the mode of the liquid crystal display by the three dimensional control of the refractive index, and the liquid crystal display device provides an image display with liquid crystals exhibiting small change in the phase contrast depending on the viewing angle.

主权项

1. An optical laminate (optical laminate C) which comprises a layer (layer A) comprising a resin having a negative intrinsic birefringence and at least one layer (layer B) comprising a transparent resin, having substantially no orientation and laminated at least on one face of layer A and satisfies a relation |Re(A)|>|Re(B)| and a relation |Re(A)|+|Re(B)|<1.1×|Re(A)|, wherein Re(A) and Re(B) represent an in-plane retardation of layer A and an in-plane retardation of layer B, respectively, measured with light having a wavelength of 400 to 700 nm,
wherein the optical laminate satisfies a relation Re(450)>Re(550)>Re(650), wherein Re(450), Re(550) and Re(650) represent in-plane retardations at wavelengths of 450 nm, 550 nm and 650 nm, respectively, wherein the optical laminate C is obtained by co-stretching an unstretched laminate comprising an unstretched resin layer comprising the transparent resin and having substantially no orientation and an unstretched resin layer comprising the resin having a negative intrinsic birefringence, said unstretched resin layer comprising the transparent resin and having substantially no orientation being laminated on at least one face of the layer comprising the resin having a negative intrinsic birefringence, wherein the unstretched laminate is co-stretched at a temperature of from Tg(A)−10 (° C.) to Tg(A)+20 (° C.), wherein Tg(A) and Tg(B) represent glass transition temperatures in ° C. of the resin of layer A and the resin of layer B, respectively, and wherein glass transition temperatures Tg(A) and Tg(B) in ° C. of the resin of layer A and the resin of layer B, respectively, satisfies a relation: Tg(B)+30>Tg(A)>Tg(B)+20.