# US 8,785,567 B2 · Liquid crystal alignment agent, film and display element

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- Number: US 8,785,567 B2
- Document ID: US8785567B2
- Status: Granted
- Kind: B2
- Application number: 13/159,300
- Filed: 2011-06-13
- Published: 2011-12-22
- Granted: 2014-07-22
- Earliest claimed: 2010-06-22
- Assignees: Chi Mei Corporation
- Applicants: Huai-Pin Hsueh
- Inventors: Huai-Pin Hsueh
- Web page: https://patentgrep.com/patent/US8785567B2

## CPC

- C08G 73/12: Unsaturated polyimide precursors
- C08L 79/085: {Unsaturated polyimide precursors}
- G02F 1/133723: {Polyimide, polyamide-imide}
- C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)
- 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

## Abstract

A liquid crystal alignment agent includes a polymer and an organic solvent for dissolving the polymer. The polymer contains a repeating structural unit represented by the following formula (I): wherein each of P and Q is a divalent organic group. The liquid crystal alignment agent has a viscosity in the range from 5 to 40 cps at 25° C. A liquid crystal alignment film made of the liquid crystal alignment agent and a liquid crystal display element including the liquid crystal alignment film are also disclosed.

## Claims

### Claim 1

A liquid crystal alignment agent, comprising:
a polymer containing a repeating structural unit represented by the following formula (I):
wherein each of P and Q is a divalent organic group; and
an organic solvent for dissolving said polymer, wherein the liquid crystal alignment agent has a viscosity ranging from 8 to 35 cps at 25° C.,
wherein said polymer is obtained by subjecting a diamine compound to polymerization in the presence of an acidic catalyst, and
wherein said diamine compound is at least one selected from the group consisting of compounds represented by the following formulas (I-1) to (I-5) and (1) to (6):
wherein
R3 is a monovalent organic group having a ring structure containing a nitrogen atom selected from the group consisting of pyridine, pyrimidine, triazine, piperidine and piperazine;
X is a divalent organic group;
R4a and R4b are independently a divalent organic group having a ring structure containing a nitrogen atom selected from the group consisting of pyridine, pyrimidine, triazine, piperidine and piperazine;
R5 and R7 are independently a divalent organic group selected from the group consisting of —O—, —COO—, —OCO—, —NHCO—, —CONH—, and —CO—;
R6 is a monovalent organic group having a group selected from the group consisting of a steroid skeleton, a trifluoromethyl group, and a fluoro group, or an alkyl group having 6 to 30 carbon atoms;
X1 and X2 are independently a divalent organic group selected from the group consisting of an alicyclic group, an aromatic group, and a heterocyclic group;
R8 is selected from the group consisting of an alkyl group having 3 to 18 carbon atoms, an alkoxy group having 3 to 18 carbon atoms, a fluoroalkyl group having 1 to 5 carbon atoms, a fluoroalkoxy group having 1 to 5 carbon atoms, a cyano group, and halogen atoms;
R9a, R9b, R9c, and R9d are independently a hydrocarbon group having 1 to 12 carbon atoms;
p is an integer ranging from 1 to 3;
q is an integer ranging from 1 to 20; and
t is an integer ranging from 2 to 12.

### Claim 2 (depends on 1)

The liquid crystal alignment agent as claimed in claim 1, wherein said organic solvent is in an amount of 400 to 10,000 parts by weight based on 100 parts by weight of said polymer.

### Claim 3 (depends on 2)

The liquid crystal alignment agent as claimed in claim 2, wherein said organic solvent is in an amount of 500 to 5,000 parts by weight based on 100 parts by weight of said polymer.

### Claim 4 (depends on 1)

A liquid crystal alignment film made of the liquid crystal alignment agent as claimed in claim 1.

### Claim 5 (depends on 4)

A liquid crystal display element, comprising the liquid crystal alignment film as claimed in claim 4.