| abstract |
The present invention relates generally to optical retardation films. The invention may be used as optical element in liquid crystal display (LCD) devices, particularly as phase-shifting component of LCDs of both reflection and transmission type, and in ant other field of science and technology where optical retardation films are applied such as architecture, automobile industry, decoration arts. The present invention provides an optical film comprising a substrate having front and rear surfaces, and at least one solid optical retardation layer on the front surface of the substrate. The solid optical retardation layer comprises organic rigid rod-like macromolecules based on 2,2′-disulfo-4,4′-benzidine terephthalamide-isophthalamide copolymer or its salt of the general structural formula I. The solid optical retardation layer is a negative C-type or Ac-type plate substantially transparent to electromagnetic radiation in the visible spectral range. |