# US 2010/0168374 A1 · Diamine compound having dendron side chain and liquid crystal aligning agent using same

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- Number: US 2010/0168374 A1
- Document ID: US20100168374A1
- Status: Published application
- Kind: A1
- Application number: 12/592,315
- Filed: 2009-11-23
- Published: 2010-07-01
- Earliest claimed: 2004-12-31
- Assignees: Cheil Industries Inc.
- Inventors: Jae Min Oh; Moo Young Lee; Bum Jin Lee; O. Bum Kwon; Won Seok Dong; Yusuke Tsuda
- Web page: https://patentgrep.com/patent/US20100168374A1

## CPC

- C08G 73/10: Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
- C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS

## Abstract

Disclosed herein is a novel functional diamine compound having a dendron structure, polyamic acid which is produced using functional diamine, aromatic cyclic diamine, aliphatic cyclic acid dianhydride, and aromatic cyclic acid dianhydride, polyimide which is produced by imidizing polyamic acid, and an LC alignment film produced using polyimide. Even if the diamine compound is used in a small amount, it is possible to realize a high pretilt angle, thus the pretilt angle is easily controlled. Therefore, it can be used to produce an LC alignment film using a twisted nematic (TN) mode, in which the pretilt angle of liquid crystal is low, and a vertically aligned (VA) mode, which requires a high pretilt angle of about 90°.

## Claims

### Claim 1

A polyamic acid, comprising:
a diamine compound according to either of Formula 1 or Formula 2;
an aliphatic cyclic acid dianhydride;
an aromatic cyclic acid dianhydride; and
optionally an aromatic cyclic diamine; wherein
the diamine compound, the aliphatic cyclic acid dianhydride, the aromatic cyclic acid dianhydride, and optionally the aromatic cyclic diamine are copolymerized, thereby producing the polyamic acid.

### Claim 2 (depends on 1)

The polyamic acid as set forth in claim 1, wherein the polyamic acid is expressed by the following Formula 4
wherein, X is one or more functional groups selected from functional groups represented by Formula 5; Y is one or more functional groups selected from functional groups represented by Formula 6; Z is one or more functional groups selected from functional groups represented by either of Formula 7 or Formula 8; and Z′ is selected from of the group represented by Formula 9;
wherein, X1, X2, X3, and X4 are each independently substituents selected from the group consisting of —CH3, —F, and —H
wherein, n is an integer from 1 to 10
wherein, A and A′ are each, independently, a single bond, or are selected from the group consisting of —O—, —COO—, —OCO—, and —NHCO—; B is a single bond or a divalent benzene ring
m is 1 to 3; n is 2 or 3; G is a single bond (when m is 1), a trivalent benzene ring
when m is 2), or a tetravalent benzene ring
when m is 3); and R is a linear, branched, or cyclic alkyl or fluoroalkyl group having 1 to 30 carbons.

### Claim 3 (depends on 1)

The polyamic acid as set forth in claim 1, wherein an average molecular weight of the polyamic acid is 5000-500,000 g/mol.

### Claim 4 (depends on 1)

The polyamic acid of claim 1, wherein content of the diamine of Formula 1 is 0.1-100 mol % and content of the aromatic cyclic diamine is 0-99.9 mol % based on total diamine monomers contained in the polyamic acid.

### Claim 5 (depends on 1)

The polyamic acid of claim 1, wherein content of the aliphatic cyclic acid dianhydride is 5-90 mol % and content of the aromatic cyclic acid dianhydride is 10-95 mol % based on total acid dianhydride contained in the polyamic acid.

### Claim 6 (depends on 1)

A polyimide compound produced by partially or totally imidizing the polyamic acid according to claim 1.

### Claim 7 (depends on 6)

The polyimide compound of claim 6 that is a liquid crystal alignment film.

### Claim 8 (depends on 1)

A liquid crystal alignment film produced by totally or partially imidizing a combination comprising the polyamic acid according to claim 1.

### Claim 9 (depends on 7)

A liquid crystal display comprising the liquid crystal alignment film according to claim 7.