Liquid crystal aligning agent composition, method for producing liquid crystal alignment film using same, and liquid crystal alignment film using same

Patent metadata

Field	Value
Publication number	US-11142697-B2
Application number	US-201816484402-A
Country	US
Kind code	B2
Filing date	Jun 26, 2018
Priority date	Jun 29, 2017
Publication date	Oct 12, 2021
Grant date	Oct 12, 2021

Abstract

The present invention relates to a liquid crystal aligning agent composition capable of securing a high imidization rate under relatively mild curing conditions, minimizing side reactions and thus having excellent stability, a method for producing a liquid crystal alignment film using the same, and a liquid crystal alignment film and a liquid crystal display device using the same.

First claim

The invention claimed is:

1. A liquid crystal aligning agent composition comprising:
i) a first polymer for a liquid crystal aligning agent including two or more repeating units selected from the group consisting of a repeating unit represented by Chemical Formula 1, a repeating unit represented by Chemical Formula 2, and a repeating unit represented by Chemical Formula 3, wherein the first polymer includes the repeating unit represented by Chemical Formula 1 in an amount of 5 mol % to 74 mol % with respect to a total of the repeating units represented by the Chemical Formulae 1 to 3,
ii) a second polymer for a liquid crystal aligning agent including a repeating unit represented by Chemical Formula 4,
iii) a compound having two or more epoxy groups in a molecule, and
iv) a catalyst including at least one selected from the group consisting of a cyclic tertiary amine compound having 1 to 10 hydroxy groups, and a linear tertiary amine compound having 2 to 10 hydroxy groups,
wherein the cyclic tertiary amine compound having 1 to 10 hydroxy groups introduced therein includes a nitrogen-containing heteroalicyclic compound containing one or more nitrogen atoms and wherein the heteroalicyclic compound contains 1 to 10 hydroxyalkyl groups each bonded to a nitrogen:
[Chemical Formula 1]

wherein, in Chemical Formulae 1 to 4,
at least one of R 1 and R 2 is a C 1-10 alkyl, and the rest is hydrogen,
R 3 and R 4 are each independently hydrogen or C 1-10 alkyl,
X 1 is a tetravalent organic group represented by Chemical Formula 5,
X 2 , X 3 , and X 4 are each independently a tetravalent organic group derived from a hydrocarbon having 4 to 20 carbon atoms, or a tetravalent organic group in which at least one H in the tetravalent organic group is substituted with a halogen, or at least one —CH 2 —is replaced by —O—, —CO—, —S—, —SO—, —SO 2 —, or —CONH— such that oxygen or sulfur atoms are not directly linked, and

wherein, in Chemical Formula 5,
R 5 to R 8 are each independently hydrogen or a C 1-6 alkyl,
Y 1 , Y 2 , Y 3 and Y 4 are each independently a divalent organic group represented by Chemical Formula 6,

wherein, in Chemical Formula 6,
R 9 and R 10 are each independently a halogen, a cyano, a C 1-10 alkyl, a C 2-10 alkenyl, a C 1-10 alkoxy, a C 1-10 fluoroalkyl, or a C 1-10 fluoroalkoxy,
p and q are each independently an integer between 0 and 4, and
L 1 is a single bond, —O—, —CO—, —S—, —SO 2 —, —C(CH 3 ) 2 —, —C(CF 3 ) 2 —, —CONH—, —COO—, —(CH 2 ) z —, —O(CH 2 ) z O—, —O(CH 2 ) z —, —OCH 2 —C(CH 3 ) 2 —CH 2 O—, —COO(—CH 2 ) z —OCO—, or —OCO—(CH 2 ) z —COO—,
wherein z is an integer between 1 and 10, and
m is an integer between 0 and 3.

2. The liquid crystal aligning agent composition of claim 1 , wherein the nitrogen-containing heteroalicyclic compound containing one or more nitrogen atoms contains 1 to 4 hydroxyalkyl groups each bonded to a nitrogen.

3. The liquid crystal aligning agent composition of claim 1 , wherein the cyclic tertiary amine compound having 1 to 10 hydroxy groups introduced therein is (2-hydroxyethyl)piperidine.

4. The liquid crystal aligning agent composition of claim 1 , wherein the linear tertiary amine compound having 2 to 10 hydroxy groups introduced therein includes an alkylene diamine compound in which 1 to 2 hydroxyalkyl groups are bonded to each nitrogen.

5. The liquid crystal aligning agent composition of claim 4 , wherein the alkylene diamine compound in which 1 to 2 hydroxyalkyl groups are bonded to each nitrogen includes an ethylene diamine in which 1 to 2 hydroxyalkyl groups are bonded to each nitrogen.

6. The liquid crystal aligning agent composition of claim 1 , wherein the linear tertiary amine compound having 2 to 10 hydroxy groups introduced therein is N,N,N′,N′-tetrakis(2-hydroxyethyl)ethylenediamine.

7. The liquid crystal aligning agent composition of claim 1 , wherein the X 2 , X 3 , and X 4 are each independently a tetravalent organic group represented by Chemical Formula 7:

wherein, in Chemical Formula 7,
R 11 to R 14 are each independently hydrogen or a C 1-6 alkyl, and L 2 is a single bond, —O—, —CO—, —S—, —C(CH 3 ) 2 —, —C(CF 3 ) 2 —, —CONH—, —COO—, —(CH 2 ) Z —, —O(CH 2 ) Z O—, or —COO—(CH 2 ) Z —OCO —, wherein z is an integer between 1 to 10.

8. The liquid crystal aligning agent composition of claim 1 , wherein a weight ratio between the first polymer for a liquid crystal aligning agent and the second polymer for a liquid crystal aligning agent is 1:9 to 9:1.

9. The liquid crystal aligning agent composition of claim 1 , wherein the molecular weight of the compound having two or more epoxy groups in a molecule is 100 g/mol to 10,000 g/mol.

10. The liquid crystal aligning agent composition of claim 1 , wherein the compound having two or more epoxy groups in a molecule is a cycloaliphatic-based epoxy, a bisphenol-based epoxy, or a novolac-based epoxy.

11. The liquid crystal aligning agent composition of claim 1 , wherein the compound having two or more epoxy groups in a molecule is included in an amount of 0.1 parts by weight to 30 parts by weight based on a total of 100 parts by weight of the first polymer for a liquid crystal aligning agent and the second polymer for a liquid crystal aligning agent.

12. A method for producing a liquid crystal alignment film comprising the steps of:
1) coating the liquid crystal aligning agent composition of claim 1 onto a substrate to form a coating film;
2) drying the coating film;
3) subjecting the coating film to alignment treatment immediately after the drying step; and
4) heat-treating and curing the alignment-treated coating film.

13. The method for producing a liquid crystal alignment film of claim 12 , wherein the liquid crystal aligning agent composition is dissolved or dispersed in an organic solvent.

14. The method for producing a liquid crystal alignment film of claim 12 , wherein the drying of Step 2 is performed at a temperature of 50° C. to 130° C.

15. The method for producing a liquid crystal alignment film of claim 12 , wherein Step 4 comprises the steps of:
4-1) subjecting the alignment-treated coating film to a low-temperature heat treatment at 200° C. or less; and
4-2) heat-treating and curing the heat-treated coating film at a temperature of higher than that of the low-temperature heat treatment.

16. The method for producing a liquid crystal alignment film of claim 15 , wherein the low-temperature heat treatment of Step 4-1 is performed at a temperature of 110° C. to 200° C.

17. The method for producing a liquid crystal alignment film of claim 15 , wherein the heat treatment of Step 4-2 is performed at a temperature of 200° C. to 250° C.

18. A liquid crystal alignment film comprising an aligned and cured product of the liquid crystal aligning agent composition of claim 1 .

19. A liquid crystal display device comprising the liquid crystal alignment film of claim 18 .

Assignees

• Lg Chemical Ltd

Inventors

• Jo Jung Ho
• Han Hee
• Min Sung Joon
• Park Hang Ah
• Lee Sang Mi
• Kwon Soon Ho
• Yoon Jun Young
• Yun Hyeong Seuk
• Kim Seongku

Classifications

• C08G59/50 Primary

  Amines · CPC title

• C08K5/3435

  Piperidines · CPC title

• G02F1/133723

  Polyimide, polyamide-imide · CPC title

• C08G73/1078

  wholly aromatic in the diamino moiety · CPC title

• C09K2323/00

  Functional layers of liquid crystal optical display excluding electroactive liquid crystal layer characterised by chemical composition · CPC title