OPTICAL ORIENTING COMPOSITION, ALIGNMENT LAYER FORMED FROM THAT COMPOSITION, AND LIQUID CRYSTAL DISPLAY ELEMENT EQUIPPED WITH THAT ALIGNMENT LAYER

摘要

PROBLEM TO BE SOLVED: To obtain an optically aligning compsn. having excellent thermal stability in which the pretilt angle can be controlled, and to obtain a liquid crystal display element excellent in thermal stability by incorporating vinyl cinnamate deriv. polymer and a polyimide in a specified weight ratio. SOLUTION: This compsn. contains a vinyl cinnamate deriv. polymer and a polyimide by 98:2 to 2:98 weight ratio. The vinyl cinnamate deriv. polymer is preferably is poly(vinyl cinnamate) or poly(vinyl methoxycinnamate), and its weight average mol.wt. ranges 5000 to 30000. The polyimide is preferably a side-chain polyimide having 5000 to 20000 weight average mol.wt. or a straight-chain polyimide having 5000 to 30000 weight average mol.wt. When the two kinds of polymers are mixed in the range above described, the vinyl cinnamate deriv. polymer has an effect to induce optical alignment while the polyimide has an effect to improve thermal stability and to produce the pretilt angle of a liquid crystal.