RETARDATION COMPENSATORS OF NEGATIVE C-TYPE FOR LIQUID CRYSTAL DISPLAY

摘要

A phase-difference compensation material of negative C-type for a liquid crystal display is provided to make a phase difference value of a thickness direction negative in the phase-difference compensation material of the same thickness. The phase-difference compensation material of negative C-type for a liquid crystal display is composed of a transparent base layer and a polyarylate coating layer stacked on the transparent base layer. The polyarylate coating layer has a thio group or a sulfur oxide group in a polymer main chain. The polyarylate coating layer has an absolute value over 10nm and a negative phase difference value of a thickness direction defined by the following formula, Rth=(n_z-n_x+n_y/2)xd. n_x is a highest refractive index in a direction of the coated surface. n_y is a refractive index perpendicular to the direction of n_x in a direction of the coated surface. n_z is a refractive index perpendicular to the plane of n_xy. d is the thickness of the coating layer.