Liquid crystal alignment agent composition, method for preparing liquid crystal alignment film using same, and liquid crystal alignment film and liquid crystal display using same

1. A liquid crystal alignment agent composition comprising:

a terminal modifier compound containing an amino group; and

a polymer containing at least one repeating unit selected from the group consisting of a repeating unit of the following Chemical Formula 1, a repeating unit of the following Chemical Formula 2, and a repeating unit of the following Chemical Formula 3, in which an acid anhydride group is bonded to at least one terminus thereof:

wherein in the Chemical Formulas 1 to 3:

one of R 1 and R 2 is an alkyl group having 1 to 10 carbon atoms and the other is hydrogen or an alkyl group having 1 to 10 carbon atoms;

X 1 to X 3 are each independently a tetravalent organic group;

Y 1 to Y 3 are each independently a divalent organic group of the following Chemical Formula 4:

wherein in the Chemical Formula 4:

A is a Group 15 element;

R 3 is one of hydrogen and an alkyl group having 1 to 10 carbon atoms;

a is an integer from 1 to 3; and

one of Z 1 and Z 3 is nitrogen and the other is carbon, and Z 2 and Z 4 are carbon.

2. The liquid crystal alignment agent composition according to claim 1 , wherein in the Chemical Formula 4, A is nitrogen, R 3 is hydrogen, and a is 1.

3. The liquid crystal alignment agent composition according to claim 1 , wherein the divalent organic group of the Chemical Formula 4 is selected from the group consisting of divalent organic groups of the following Chemical Formulas 4-1, 4-2, and 4-3:

4. The liquid crystal alignment agent composition according to claim 1 , wherein X 1 to X 3 are each independently a tetravalent organic group having one of the following formulas:

wherein:

R 4 to R 9 are each independently hydrogen or an alkyl group having 1 to 10 carbon atoms;

L 1 is any one selected from the group consisting of a direct bond, —O—, —CO—, —S—, —SO—, —SO 2 —, —CR 10 R 11 —, —CONH—, —COO—, —(CH 2 ) b —, —O(CH 2 ) b —O—, —COO—(CH 2 ) b —OCO—, phenylene, and a combination thereof;

R 10 and R 11 are each independently hydrogen, an alkyl group having 1 to 10 carbon atoms, or a haloalkyl group having 1 to 10 carbon atoms; and

b is an integer from 1 to 10.

5. The liquid crystal alignment agent composition according to claim 1 , wherein the terminal modifier compound containing an amino group is a compound of the following Chemical Formula 6:

wherein in the Chemical Formula 6:

L 2 and L 3 are each independently any one selected from among a direct bond, —O—, —CO—, —S—, —CONH—, —COO—, —O(CH 2 ) t O—, —COO—(CH 2 ) t —OCO—, an alkylene group having 1 to 10 carbon atoms, a haloalkylene group having 1 to 10 carbon atoms, a cycloalkylene group having 3 to 20 carbon atoms, a heterocycloalkylene group having 3 to 20 carbon atoms, an arylene group having 6 to 30 carbon atoms, and a heteroarylene group having 3 to 20 carbon atoms;

t is an integer from 1 to 10; and

X is any one of hydrogen, a hydroxy group, a nitro group, and an alkyl group having 1 to 10 carbon atoms.

6. The liquid crystal alignment agent composition according to claim 1 , wherein the content of the terminal modifier compound containing an amino group is 0.1% to 20% by weight based on the total weight of the liquid crystal alignment agent composition.

7. The liquid crystal alignment agent composition according to claim 1 , wherein the polymer includes:

a first polymer containing at least one repeating unit selected from the group consisting of the repeating unit of the Chemical Formula 1, the repeating unit of the Chemical Formula 2, and the repeating unit of the Chemical Formula 3 in which an acid anhydride group is bonded to at least one terminus thereof; and

a second polymer containing at least one repeating unit selected from the group consisting of the repeating unit of the Chemical Formula 1, the repeating unit of the Chemical Formula 2, and the repeating unit of the Chemical Formula 3 and having at least one terminal functional group selected from the group consisting of the following Chemical Formulas 7, 8, and 9 at one or more termini thereof:

wherein in the Chemical Formulas 7 to 9:

one of R 1 ′ and R 2 ′ is an alkyl group having 1 to 10 carbon atoms and the other is hydrogen or an alkyl group having 1 to 10 carbon atoms;

X 1 ′ to X 3 ′ are each independently a tetravalent organic group;

Y 1 ′ to Y 3 ′ are each independently a divalent organic group of the following Chemical Formula 4;

L 2 ′ and L 3 ′ are each independently any one selected from among a direct bond, —O—, —CO—, —S—, —CONH—, —COO—, —O(CH 2 ) t O—, —COO—(CH 2 ) t —OCO—, an alkylene group having 1 to 10 carbon atoms, a haloalkylene group having 1 to 10 carbon atoms, a cycloalkylene group having 3 to 20 carbon atoms, a heterocycloalkylene group having 3 to 20 carbon atoms, an arylene group having 6 to 30 carbon atoms, and a heteroarylene group having 3 to 20 carbon atoms;

t is an integer from 1 to 10; and

X′ is hydrogen, a hydroxy group, a nitro group, or an alkyl group having 1 to 10 carbon atoms;

wherein in the Chemical Formula 4:

A is a Group 15 element;

R 3 is one of hydrogen and an alkyl group having 1 to 10 carbon atoms;

a is an integer from 1 to 3; and

at least one of Z 1 to Z 4 is nitrogen and the rest are carbon.

8. The liquid crystal alignment agent composition according to claim 7 , wherein the second polymer is contained in an amount from 0.5% to 40% by weight based on the total weight of the liquid crystal alignment agent composition.

9. A method for preparing a liquid crystal alignment film, comprising the steps of:

coating the liquid crystal alignment agent composition of claim 1 onto a substrate to form a coating film;

drying the coating film;

irradiating the dried coating film with light or rubbing the dried coating film to perform alignment treatment; and

heat-treating and curing the alignment-treated coating film.

10. The method for preparing a liquid crystal alignment film according to claim 9 , wherein the step of drying the coating film is performed at a temperature of 50° C. to 150° C.

11. The method for preparing a liquid crystal alignment film according to claim 9 , wherein the step of heat-treating and curing the alignment-treated coating film is performed at a temperature of 180° C. to 300° C.

12. A liquid crystal alignment film, prepared by the method of claim claim 9 .

13. A liquid crystal alignment film, comprising an aligned cured product of the liquid crystal alignment agent composition of claim 1 .

14. A liquid crystal display, comprising the liquid crystal alignment film of claim 13 .