Nissan Chemical Industries Limited

Makoto Mishina

Hiroyoshi Fukuro

Terumi Sato

Toyohiko Abe

Kiyoshi Sawahata

Atsuko Tanaka

Yoshio Miyamoto

Yoshihiro Tsuruoka

Syunichi Sano

Motoaki Ishikawa

Aligning agent for liquid-crystal cells

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.4 is a bivalent organic group which constitutes a diamine, and m and k are positive integers).

Treating agent for liquid crystal alignment

A polyimide varnish which is a solution having a polyimide and/or a polyimide precursor dissolved in an organic solvent and which is useful for forming a polyimide coating film on a substrate by coating the solution on the substrate followed by heat treatment, wherein from 5 wt % to 60 wt % of the organic solvent is a polypropylene glycol derivative of the formula (I): ##STR1## wherein n is 1 or 2, and R is hydrogen, a C.sub.1-4 alkyl group, a C.sub.1-4 alkenyl group or a C.sub.1-4 alkanoyl group.

Polyimide varnish

A polyimide varnish which is a solution having a polyimide and/or a polyimide precursor dissolved in an organic solvent and which is useful for forming a polyimide coating film on a substrate by coating the solution on the substrate followed by heat treatment, wherein from 5 wt % to 60 wt % of the organic solvent is a lactic acid derivative of the formula (I): ##STR1## wherein each of R.sup.1 and R.sup.2 which are independent of each other, is hydrogen, a C.sub.1-5 alkyl group or a C.sub.1-5 alkenyl group.

An agent for alignment treatment for a liquid crystal cell, which comprises an organic solvent-soluble polyimide obtained by reacting and polymerizing a tetracarboxylic acid component with a diamine component and a dicarboxylic acid component containing a long chain alkyl group and/or a monoamine component containing a long chain alkyl group, followed by imide-formation.

Agent for alignment treatment for a liquid crystal cell

The present invention relates to an alignment treating agent for a liquid crystal cell, which comprises an organic solvent-soluble polyimide resin comprising a tetracarboxylic acid and a diamine, at least 10 mol % of the diamine having a bivalent organic group selected from the group consisting of: ##STR1## The aligned film for a liquid crystal using the solvent-soluble polyimide resin of the present invention does not require a heat treatment at a high temperature at the time of forming a resin film and enables to use a substrate poor in heat-resistance, and alignment properties such as a tilt angle and a voltage maintenance of the aligned film are not deteriorated even after durability test at a high temperature.

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Funabashi, Japan

Makoto Mishina