LIQUID CRYSTAL ALIGNING AGENT FOR VERTICAL ALIGNMENT, ALIGNMENT LAYER FOR LIQUID CRYSTAL, AND LIQUID CRYSTAL DISPLAYS MADE BY USING THE SAME

摘要

A liquid crystal aligning agent for vertical alignment to be used in a liquid crystal display which bears an electrode on at least one of the pair of substrates and is driven by applying a voltage to a vertically aligned liquid crystal, containing a polyamic acid which is represented by the general formula (I) and exhibits a reduced viscosity of 0.05 to 5.0 dl/g (in N-methyl-2- pyrrolidone at 30°C at a concentration of 0.5g/dl) or a polyimide obtained by cyclodehydration thereof: (I) wherein R1 represents a tetravalent organic group, at least 20 mole % of which has a fused alicyclic structure composed of two to five rings, with the provisos that all of the carbonyl groups are directly bonded to the alicyclic structure and that any two carbonyl groups are not bonded to adjacent carbon atoms of the alicyclic structure; R2 is a divalent organic group, 20 to 100 mole % of which has in the side-chain structure at least one kind of structural units selected from the group consisting of C5-20 long-chain alkyl, C5-20 fluoroalkyl, alicyclic structures and aromatic ring structures; and L is a positive integer.