Patent ID: 9488866
Filing Date: 2016-11-08
CPC Classification: C09K,G02B,G02F,Y10T

Claim Text:
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.