COLORLESS POLYIMIDE RESIN, AND LIQUID CRYSTAL ALIGNMENT LAYER AND POLYIMIDE FILM USING THE SAME

摘要

A colorless and transparent polyimide resin is provided to be superior in mechanical properties and physical properties such as heat stability, and to be usable for a liquid crystal alignment layer and an optical communication material. A polyimide resin includes 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride as an aromatic dianhydride, and hexamethylenediamine as an aromatic diamine. The aromatic diamine further comprises a component represented by the following formula 1 of H2N-R-NH2, wherein R is a structure selected from the formula 2. A liquid crystal alignment layer comprises the polyimide resin, and has a pretilt angle(alpha) of 0-2 degree.