| 摘要 |
PURPOSE:To stabilize the orientability of a liquid crystal by forming a liquid crystal oriented film of the arom. polyimide having the repeating units expressed by the general formulas. CONSTITUTION:The arom. polyimide obtd. from specific arom. tetracarboxylic acid di-anhydride and arm. diamine is used as the liquid crystal oriented film. Namely, the liquid crystal oriented film consists of the arom. polyimide having the repeating units expressed by the general formulas I and II. In the formulas, Ra, Rb, Rc, Rd denote a hydrogen atom, chlorine atom, bromine atom., lower alkyl group or lower alkoxyl group which may be the same as or different from each other; Re, Rf are a hydrogen atom, methyl group, trichloromethyl group or ethyl group which may be the same as or different from each other; Ar denotes the formula III or IV. The liquid crystal oriented film which has good coatability, provides the stable orientability of the liquid crystal and can maintain a high tilt angle without fluctuation thereof and the liquid crystal display element formed with said film are obtd. |
