# US 6,294,639 B1 · Liquid crystal aligning agent

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- Number: US 6,294,639 B1
- Document ID: US6294639B1
- Status: Granted
- Kind: B1
- Application number: 09/554,622
- Filed: 2000-06-02
- Granted: 2001-09-25
- Earliest claimed: 1997-12-02
- Assignees: Nissan Chemical Industries, Ltd.
- Inventors: Kiyoshi Sawahata; Hideyuki Nawata; Takayasu Nihira; Yoshikazu Ohtsuka; Yasuyuki Nakajima
- Web page: https://patentgrep.com/patent/US6294639B1

## CPC

- C08G 73/10: Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
- G02F 1/133723: {Polyimide, polyamide-imide}
- C09K 2323/00: Functional layers of liquid crystal optical display excluding electroactive liquid crystal layer characterised by chemical composition
- C09K 2323/02: Alignment layer characterised by chemical composition
- C09K 2323/027: Polyimide
- Y10T 428/31721: Of polyimide
- C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## 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.

## Claims

### Claim 1

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 compound obtained by imidizing said polyamic acid compound.

### Claim 2 (depends on 1)

The treating agent for liquid crystal alignment according to claim 1, wherein R1 in the general formula [I] is a tetravalent organic group constituting a tetracarboxylic acid represented by the general formula [II]:
(wherein each of X1, X2, X3 and X4 which are independent of one another, is a single bond or a methylene group, and m is an integer of from 1 to 3).

### Claim 3 (depends on 1)

The treating agent for liquid crystal alignment according to claim 1, wherein R1 in the general formula [I] is a tetravalent organic group constituting a tetracarboxylic acid represented by the formula [III]:

### Claim 4 (depends on 1)

The treating agent for liquid crystal alignment according to claim 1, wherein the formula [III] is a single component selected from isomers of the formulae [IV] to [VI], or a mixture thereof:

### Claim 5 (depends on 1)

The treating agent for liquid crystal alignment according to claim 1, which comprises at least one member selected from polymers having an imidization degree a% of 0<a≦100% of the polyimide obtained by imidizing the polyamic acid compound represented by the general formula [I].

### Claim 6 (depends on 1)

The treating agent for liquid crystal alignment according to claim 1, wherein R2 in the general formula [I] comprises a bivalent organic group constituting a diamine having a long chain alkyl group with a carbon number of at least 6, or a fluorine-containing alkyl group with a carbon number of at least 6.

### Claim 7 (depends on 1)

A treating agent for liquid crystal alignment, wherein the polyamic acid compound represented by the general formula [I] of claim 1 or the polyimide compound obtained by imidizing said polyamic acid compound, is mixed in an amount of at least 10 wt % based on the total polymer weight, with a polyamic acid compound represented by the general formula [VII]:
wherein R3 is a tetravalent organic group constituting a tetracarboxylic acid, and R4 is a bivalent organic group constituting a diamine having a reduced viscosity of from 0.05 to 5.0 dl/g in N-methylpyrrolidone at a temperature of 30° C. at s concentration of 0.5 g/dl.

### Claim 8 (depends on 7)

The treating agent for liquid crystal alignment according to claim 7, wherein, in the polyamic acid compound of the general formula [VII], R3 contains a tetravalent organic group constituting an aliphatic tetracarboxylic dianhydride.

### Claim 9 (depends on 1, 2, 3, 4, 5, 6, 7, 8)

A liquid crystal alignment film obtained by coating on a substrate the treating agent for liquid crystal alignment as in one of claims 1-8, followed by baking, and then applying rubbing treatment to the surface of the coating film.

### Claim 10 (depends on 1, 2, 3, 4, 5, 6, 7, 8)

A liquid crystal device which comprises a liquid crystal alignment film obtained by coating on a substrate the treating agent for liquid crystal alignment as in one of claims 1-8, followed by baking, and then applying rubbing treatment to the surface of the coating film.

### Claim 11 (depends on 1)

The treating agent for liquid crystal alignment according to claim 1, wherein R1 in the general formula [I] is a tetravalent organic group constituting a tetracarboxylic acid represented by general formulas [VIII], [IX], [X] or [XI]:

### Claim 12 (depends on 1)

The treating agent for liquid crystal alignment according to claim 1, wherein R2 is selected from the group consisting of aromatic diamines, alicyclic diamines, aliphatic diamines and silicon diamines, or mixtures thereof.