Abstract: To provide a liquid crystal alignment treating agent to obtain a liquid alignment film of polyamide type which, in its applications to various display devices employing nematic liquid crystal, is excellent in voltage retention, has a reduced charge accumulation and is excellent in durability against rubbing treatment, and a liquid crystal display device employing it.

Abstract: An alignment treating agent for a liquid crystal cell, which comprises a polyimide resin of the formula (I): wherein R1 is a tetravalent organic group constituting a tetracarboxylic acid or its derivative, R2 is a bivalent organic group constituting a diamine, and m is a positive integer, provided that at least 10 mol % of R2 is a bivalent organic group selected from the group consisting of: wherein X is H, OH, an alkyl group, an alkoxy group, a carboxyl group, an acyl group or a halogen atom, said polyimide resin being made insoluble in an organic solvent by coating a precursor solution of said polyimide resin on a substrate, followed by heating.

Abstract: The present invention relates to a treating agent for liquid crystal alignment, which comprises a polyamic acid compound having a reduced viscosity of from 0.05 to 5.0 dl/g (in N-methylpyrrolidone at a temperature of 30° C. at a concentration of 0.5 g/dl) and containing repeating units represented by the general formula [I]: (wherein R1 is a tetravalent organic group constituting a tetracarboxylic acid which has an alicyclic structure having from 2 to 5 rings condensed and wherein all the carbonyl groups are directly bonded to the alicyclic structure and said carbonyl groups are not bonded to adjacent carbon atoms in the alicyclic structure, and R2 is a bivalent organic group constituting a diamine), or a polyimide resin obtained by imidizing said polyamic acid compound, and a liquid crystal alignment film and a liquid crystal device employing it.

Abstract: A treating agent for liquid crystal alignment, which comprises a polyimide precursor containing repeating units of the formula (1) and having a polymerization degree of from 0.05 to 5.0 dl/g as calculated as the reduced viscosity (in N-methylpyrrolidone at a temperature of 30.degree. C. at a concentration of 0.5 g/dl), and a solvent-soluble polyimide containing repeating units of the formula (2) and having a polymerization degree of from 0.05 to 5.0 dl/g as calculated as the reduced viscosity (in N-methylpyrrolidone at a temperature of 30.degree. C. at a concentration of 0.5 g/dl): ##STR1## wherein each of R.sup.1 and R.sup.3 is a tetravalent organic group constituting a tetracarboxylic acid or its derivative, R.sup.2 is a bivalent organic group constituting a diamine, R.sup.4 is a bivalent organic group constituting a diamine having no fluorine-containing alkyl group or no long chain alkyl group having at least 6 carbon atoms, and each of m and n is a positive integer.

Abstract: A treating agent for liquid crystal alignment useful for formation of a liquid crystal alignment film obtained by coating a film on a substrate equipped with transparent electrodes, baking the film, and subjecting the film surface to a rubbing treatment, wherein the treating agent for liquid crystal alignment contains a polyimide precursor containing a repeating unit of the formula (I) and a solvent-soluble polyimide resin containing a repeating unit of the formula (II), and at least 1 mol % of R.sub.4 of the solvent-soluble polyimide resin of the formula (II) being a bivalent organic group constituting a diamine which has a long-chain alkyl group or fluorine-containing alkyl group with a carbon number of at least 6, and the solvent-soluble polyimide resin of the formula (II) being from 1 to 80% by weight based on the total polymer weight: ##STR1## (wherein each of R.sub.1 and R.sub.2 is a tetravalent organic group which constitutes tetracarboxylic acid or its derivative, each of R.sub.2 and R.sub.

Abstract: A treating agent for liquid crystal alignment useful for formation of a liquid crystal alignment film obtained by coating a film on a substrate equipped with transparent electrodes, baking the film, and subjecting the film surface to a rubbing treatment, wherein the treating agent for liquid crystal alignment contains a polyimide precursor containing a repeating unit of the formula (I) and a solvent-soluble polyimide resin containing a repeating unit of the formula (II), and at least 1 mol % of R.sub.4 of the solvent-soluble polyimide resin of the formula (II) being a bivalent organic group constituting a diamine which has a long-chain alkyl group or fluorine-containing alkyl group with a carbon number of at least 6, and the solvent-soluble polyimide resin of the formula (II) being from 1 to 80% by weight based on the total polymer weight: ##STR1## (wherein each of R.sub.1 and R.sub.2 is a tetravalent organic group which constitutes tetracarboxylic acid or its derivative, each of R.sub.2 and R.sub.