Abstract: The present invention relates to a novel polyimide copolymer, a method of preparing the polyimide copolymer, a liquid crystal aligning layer including the polyimide copolymer, a method of producing the liquid crystal aligning layer, and a liquid crystal display including the liquid crystal aligning layer. The liquid crystal aligning layer that includes the polyimide copolymer according to the present invention is advantageous in that when ultraviolet rays are radiated on movable chains of the polyamic acid copolymer to perform alignment before a polyimide copolymer is imidized and heat treatment is then performed to conduct imidization, thermal stability is excellent, residual images are not formed, and alignment of liquid crystals is excellent.

Abstract: Disclosed is polyimide of the following Formula 1, a polyamic acid which is a precursor of the polyimide, and a method for preparing thereof. In Formula 1, R is a tetravalent organic group, and n is an integer of 1 to 1000. A liquid crystal alignment layer which contains the polyimide according to the present invention has excellent thermal stability, no residual images, and excellent alignment of liquid crystals.