JP5316752B2 - Liquid crystal aligning agent and liquid crystal display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal alighning agent excellent in liquid crystal alighnment properties, electrical properties and printability. <P>SOLUTION: The liquid crystal alighning agent contains at least one polymer selected from the group consisting of polyamic acids, which are obtained by reacting tetracarboxylic acid dianhydrides with diamines containing the compounds shown by formula (A), and polymers obtained by imidizing the polyamic acids. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a liquid crystal aligning agent and a liquid crystal display element. More specifically, the present invention relates to a liquid crystal aligning agent that can provide a liquid crystal alignment film having excellent liquid crystal alignment properties and electrical characteristics, and excellent printability, and a liquid crystal display element excellent in display quality.

Currently, as a liquid crystal display element, a liquid crystal alignment film made of polyamic acid, polyimide, or the like is formed on the surface of a substrate on which a transparent conductive film is provided to form a liquid crystal display element substrate. A nematic liquid crystal layer having positive dielectric anisotropy is formed in a cell having a sandwich structure so that the major axis of the liquid crystal molecules is continuously twisted by 90 ° from one substrate to the other. A TN type liquid crystal display element having a TN type (Twisted Nematic) liquid crystal cell is known.
Furthermore, an STN (Super Twisted Nematic) type liquid crystal display element capable of realizing a high contrast ratio as compared with a TN type liquid crystal display element, an IPS (In-Plane Switching) type liquid crystal display element with less viewing angle dependency, and less viewing angle dependency. In addition, an optically compensated bend (OCB) type liquid crystal display element excellent in high-speed response of an image screen, a VA (Vertical Alignment) type liquid crystal display element using nematic liquid crystal having negative dielectric anisotropy, and the like are known ( (See Patent Documents 1 to 6 and Non-Patent Documents 1 to 5). Also in such a liquid crystal display element, the alignment control of the liquid crystal molecules is usually performed by a liquid crystal alignment film mainly composed of these polymers formed by a liquid crystal alignment agent containing a polymer such as polyamic acid or polyimide. Yes.
Such a liquid crystal alignment film is required to have good liquid crystal alignment performance, high voltage holding ratio, and performance such as no afterimage.

By the way, in recent years, liquid crystal display elements have been increasing in aperture ratio and resolution in order to obtain brighter and more beautiful images. With the development of larger screens and moving image fixing technology, liquid crystal display elements are required to have finer and more beautiful displays, and it is essential to be able to respond quickly and accurately to the rapid movement of advanced moving images. It has become. For this reason, the liquid crystal alignment film is required to have a high degree of uniformity over the entire surface of the film as well as the above-mentioned various performances. In particular, there is a demand for a high degree of printability in offset printing that is widely employed in the process of forming a liquid crystal alignment film.
However, a material satisfying a high degree of printability without impairing the above-mentioned various performances conventionally required for a liquid crystal alignment film is not yet known.
JP-A-4-153622 JP 60-107020 A JP 56-91277 A U.S. Pat. No. 5,928,733 Japanese Patent Laid-Open No. 11-258605 Japanese Patent Laid-Open No. 62-165628 JP 2002-327058 A JP-A-6-222366 JP-A-6-281937 JP-A-5-107544 Liq. Cryst. , Vol. 22, 379 (1996) Liquid crystal, vol. 3, no. 2, 117 (1999) Liquid crystal, vol. 3, no. 4, 272 (1999) Jpn. Appl. phys. , Vol. 36, 428 (1997) SID '94 Digest, p. 927 (1997) Journal of Organic Chemistry, 34, 1550 (1969) Journal of Organic Chemistry, 23, 151 (1958)

An object of the present invention is to provide a liquid crystal alignment film having excellent liquid crystal alignment properties and electrical characteristics, and also to a liquid crystal alignment agent excellent in printability and a display quality capable of quickly and accurately responding to quick movement of advanced moving images. The object is to provide an excellent liquid crystal display element.
Still other objects and advantages of the present invention will become apparent from the following description.

According to the present invention, the above objects and advantages of the invention are firstly:
Tetracarboxylic dianhydride and the following formula (A)

(In formula (A), X is a single bond, a methylene group or an ethylene group.)
Achieved by a liquid crystal aligning agent containing at least one polymer selected from the group consisting of a polyamic acid obtained by reacting with a diamine containing a compound represented by the formula:
This is achieved by a liquid crystal display device comprising a liquid crystal alignment film formed from the liquid crystal alignment agent.

  The liquid crystal alignment film of the present invention provides a liquid crystal alignment film excellent in printability and excellent in liquid crystal alignment and electrical characteristics (particularly voltage holding ratio, residual voltage characteristics, etc.). The liquid crystal alignment film of the present invention is suitable for liquid crystal display elements of various display modes such as TN type, STN type, VA type, SH (Super Homeotropic) type, IPS type, OCB type, ferroelectricity, and antiferroelectricity. Can adapt to. The liquid crystal display element of the present invention comprising the liquid crystal alignment film formed from the liquid crystal alignment film of the present invention can quickly and accurately respond to quick movements of advanced moving images, and has excellent display quality. The liquid crystal display element of the present invention can be suitably used for various display devices such as a desk calculator, a wristwatch, a table clock, a counting display board, a word processor, a personal computer, and a liquid crystal television.

Hereinafter, the present invention will be described in detail.
The liquid crystal aligning agent of the present invention is selected from the group consisting of a polyamic acid obtained by reacting a tetracarboxylic dianhydride and a diamine containing a compound represented by the above formula (A) and an imidized polymer thereof. At least one polymer.
<Tetracarboxylic dianhydride>
Examples of the tetracarboxylic dianhydride used for synthesizing the polyamic acid in the present invention include butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2- Dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dichloro-1,2, 3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetra Carboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3 ′, 4,4′-dicyclohexyltetracarboxylic dianhydride, 2,3,5-to Carboxymethyl cyclopentyl acetic dianhydride, 3,5,6-tri-carboxy-norbornane-2-acetic dianhydride, 2,3,4,5-tetrahydrofuran tetracarboxylic dianhydride,

1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3 , 3a, 4,5,9b-Hexahydro-5-methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3 , 3a, 4,5,9b-Hexahydro-5-ethyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1, 3,3a, 4,5,9b-hexahydro-7-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, , 3,3a, 4,5,9b-Hexahydro-7-ethyl-5- (teto Hydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5 (Tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8-ethyl-5 -(Tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5,8- Dimethyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 5- (2,5-dioxotetrahydrofuranyl) -3- Methyl-3-cyclohexene-1,2-dicarboxylic anhydride, bi Chlo [2.2.2] -oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 3-oxabicyclo [3.2.1] octane-2,4-dione-6 -Spiro-3 '-(tetrahydrofuran-2', 5'-dione), 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride 3,5,6-tricarboxy-2-carboxynorbornane-2: 3,5: 6-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^2,6 ] undecane-3 , 5, 8, 10-tetraone, the following formulas (TI) and (T-II)

(In the formulas (T-I) and (T-II), R ¹ and R ³ each represent a divalent organic group having an aromatic ring, and R ² and R ⁴ each represent a hydrogen atom or an alkyl group. And a plurality of R ² and R ⁴ may be the same or different.)
An aliphatic or alicyclic tetracarboxylic dianhydride such as a compound represented by each of the following:
Pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenylsulfone tetracarboxylic dianhydride, 1,4,5, 8-naphthalene tetracarboxylic dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyl ether tetracarboxylic dianhydride, 3,3 ′, 4,4′-dimethyldiphenylsilanetetracarboxylic dianhydride, 3,3 ′, 4,4′-tetraphenylsilanetetracarboxylic dianhydride, 1,2,3,4-furantetracarboxylic dianhydride 4,4′-bis (3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenylsulfone dianhydride, 4,4′-bis ( 3,4-dicar Boxyphenoxy) diphenylpropane dianhydride, 3,3 ′, 4,4′-perfluoroisopropylidene diphthalic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2 , 2 ′, 3,3′-biphenyltetracarboxylic dianhydride, bis (phthalic acid) phenylphosphine oxide dianhydride, p-phenylene-bis (triphenylphthalic acid) dianhydride, m-phenylene-bis ( Triphenylphthalic acid) dianhydride, bis (triphenylphthalic acid) -4,4′-diphenyl ether dianhydride, bis (triphenylphthalic acid) -4,4′-diphenylmethane dianhydride, ethylene glycol-bis ( Anhydrotrimellitate), propylene glycol-bis (anhydrotrimellitate), 1,4-butanediol-bis (anhydrotrimellitate) Retate), 1,6-hexanediol-bis (anhydrotrimellitate), 1,8-octanediol-bis (anhydrotrimellitate), 2,2-bis (4-hydroxyphenyl) propane-bis ( Anhydrotrimellitate), the following formulas (T-1) to (T-4)

An aromatic tetracarboxylic dianhydride such as a compound represented by each of the above can be exemplified. These may be used alone or in combination of two or more.
Among these, the tetracarboxylic dianhydride used for synthesizing the polyamic acid in the present invention includes butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3 , 3a, 4,5,9b-Hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3 , 3 , 4,5,9b-Hexahydro-5,8-dimethyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, bicyclo [2 , 2,2] -Oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 3-oxabicyclo [3.2.1] octane-2,4-dione-6-spiro- 3 ′-(tetrahydrofuran-2 ′, 5′-dione), 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride, 3, 5,6-tricarboxy-2-carboxynorbornane-2: 3,5: 6-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^2,6 ] undecane-3,5 8,10-tetraone, pyromellitic dianhydride, 3,3 ′ 4,4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenylsulfone tetracarboxylic dianhydride, 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride, Among the compounds represented by 1,4,5,8-naphthalenetetracarboxylic dianhydride and the above formula (TI), the following formulas (T-5) to (T-7)

Of the compounds represented by each of the above and the compounds represented by the above formula (T-II), the following formula (T-8)

It is preferable that the liquid crystal alignment film to be formed has at least one selected from the group consisting of the compounds represented by (hereinafter referred to as “specific tetracarboxylic dianhydride”). It is preferable in that it can be expressed. Particularly preferred specific tetracarboxylic dianhydrides are 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 1,3,3a, 4,5. , 9b-Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro -8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 3-oxabicyclo [3.2.1] octane- 2,4-dione-6-spiro-3 ′-(tetrahydrofuran-2 ′, 5′-dione), 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1 No 2-dicarboxylic acid Things, 3,5,6-tricarboxy-2-carboxymethyl norbornane -2: 3,5: 6-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^{2, 6]} undecane - It is at least one selected from the group consisting of 3,5,8,10-tetraone, pyromellitic dianhydride and a compound represented by the above formula (T-1).
The tetracarboxylic dianhydride used for synthesizing the polyamic acid in the present invention contains 20 mol% or more of the specific tetracarboxylic dianhydride as described above with respect to the total tetracarboxylic dianhydride. It is more preferable that it contains 50 mol% or more, and it is particularly preferable that 80 mol% or more is included.

<Diamine>
The diamine used for synthesizing the polyamic acid in the present invention includes a compound represented by the above formula (A).
The two amino groups in the above formula (A) are preferably in the 2,4 or 2,5 position relative to X when X is a single bond, and when X is a methylene group or an ethylene group It is preferable that they are in the 2,4 or 3,5 position with respect to X. X is preferably a single bond or a methylene group.
Specific examples of the compound represented by the above formula (A) include, for example, the following formulas (A-1) to (A-4):

And the like, and the like.
The compound represented by the above formula (A) can be easily synthesized by appropriately combining organic chemistry methods.
For example, the compounds represented by the above formulas (A-1) and (A-2) are each reacted with dinitrophenol at a desired substitution position after treating tetrahydroabietic acid with thionyl chloride to form an acid chloride. To obtain a dinitro compound, and further, this dinitro compound can be synthesized by reduction with an appropriate reduction system such as palladium carbon / hydrazine or tin chloride.
In the compounds represented by the above formulas (A-3) and (A-4), tetrahydroabietic acid is reacted with dinitrobenzyl chloride at a desired substitution position in the presence of a suitable base such as potassium carbonate. Thus, a dinitro compound can be obtained, and the dinitro compound can be synthesized by reducing with an appropriate reduction system such as palladium carbon / hydrazine or tin chloride.
As described in Non-Patent Document 6 (Jornal of Organic Chemistry, Vol. 34, page 1550 (1969)), tetrahydroabietic acid as a raw material is used under high temperature and high pressure in the presence of Raney nickel in an ethanol solvent. A method of reducing abietic acid with an acid;
As described in Non-Patent Document 7 (Jornal of Organic Chemistry, Vol. 23, page 151 (1958)), di-n-amylamine salt of abietic acid is converted to 7,8-dihydroabietine with a lithium / liquid ammonia catalyst. After reduction to an acid, it can be further synthesized by a method of catalytic hydrogenation using a platinum catalyst, or a commercially available product can be used.

  As the diamine used for synthesizing the polyamic acid in the present invention, only the compound represented by the above formula (A) may be used, or other diamine other than the compound represented by the above formula (A). May be used in combination. Examples of such other diamines include p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylethane, 4,4′-diaminodiphenyl sulfide, and 4,4′-diamino. Diphenyl sulfone, 3,3′-dimethyl-4,4′-diaminobiphenyl, 4,4′-diaminobenzanilide, 4,4′-diaminodiphenyl ether, 1,5-diaminonaphthalene, 2,2′-dimethyl-4 , 4′-diaminobiphenyl, 3,3′-dimethyl-4,4′-diaminobiphenyl, 2,2′-ditrifluoromethyl-4,4′-diaminobiphenyl, 3,3′-ditrifluoromethyl-4, 4′-diaminobiphenyl, 5-amino-1- (4′-aminophenyl) -1,3,3-trime Luindan, 6-amino-1- (4′-aminophenyl) -1,3,3-trimethylindane, 3,4′-diaminodiphenyl ether, 3,3′-diaminobenzophenone, 3,4′-diaminobenzophenone, 4 , 4′-diaminobenzophenone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] sulfone, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4- Aminophenoxy) biphenyl, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene Zen, 9,9-bis (4-aminophenyl) -10-hydroanthracene, 2,7-diaminofluorene, 9,9-dimethyl-2,7-diaminofluorene, 9,9-bis (4-aminophenyl) Fluorene, 4,4′-methylene-bis (2-chloroaniline), 2,2 ′, 5,5′-tetrachloro-4,4′-diaminobiphenyl, 2,2′-dichloro-4,4′- Diamino-5,5′-dimethoxybiphenyl, 3,3′-dimethoxy-4,4′-diaminobiphenyl, 1,4,4 ′-(p-phenyleneisopropylidene) bisaniline, 4,4 ′-(m-phenylene) Isopropylidene) bisaniline, 2,2′-bis [4- (4-amino-2-trifluoromethylphenoxy) phenyl] hexafluoropropane, 4,4′-diamino- , 2'-bis (trifluoromethyl) biphenyl, 4,4'-bis [(4-amino-2-trifluoromethyl) phenoxy] - aromatic diamines such as octafluoro biphenyl;

1,1-metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, 4,4-diaminoheptamethylenediamine, 1 , 4-diaminocyclohexane, isophoronediamine, tetrahydrodicyclopentadienylenediamine, hexahydro-4,7-methanoindanylene methylenediamine, tricyclo [6.2.1.0 ^2,7 ] -undecylenedimethyldiamine, 4 Aliphatic or cycloaliphatic diamines such as 1,4′-methylenebis (cyclohexylamine), 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane;
2,3-diaminopyridine, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 5,6-diamino-2,3-dicyanopyrazine, 5,6-diamino-2,4 -Dihydroxypyrimidine, 2,4-diamino-6-dimethylamino-1,3,5-triazine, 1,4-bis (3-aminopropyl) piperazine, 2,4-diamino-6-isopropoxy-1,3 , 5-triazine, 2,4-diamino-6-methoxy-1,3,5-triazine, 2,4-diamino-6-phenyl-1,3,5-triazine, 2,4-diamino-6-methyl -S-triazine, 2,4-diamino-1,3,5-triazine, 4,6-diamino-2-vinyl-s-triazine, 2,4-diamino-5-phenylthiazole, 2,6- Aminopurine, 5,6-diamino-1,3-dimethyluracil, 3,5-diamino-1,2,4-triazole, 6,9-diamino-2-ethoxyacridine lactate, 3,8-diamino-6 Phenylphenanthridine, 1,4-diaminopiperazine, 3,6-diaminoacridine, bis (4-aminophenyl) phenylamine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, N-ethyl -3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N, N'-bis (4-aminophenyl) -benzidine, N, N'-bis (4-aminophenyl) -N, N '-Dimethyl-benzidine, the following formula (DI)

(In the formula (DI), R ⁵ represents a monovalent organic group having a ring structure containing a nitrogen atom selected from pyridine, pyrimidine, triazine, piperidine and piperazine, and X ¹ represents a divalent organic group. .)
A compound represented by formula (D-II):

（式（Ｄ−ＩＩ）中、Ｒ^６はピリジン、ピリミジン、トリアジン、ピペリジンおよびピペラジンから選ばれる窒素原子を含む環構造を有する２価の有機基を示し、Ｘ^２は、それぞれ、２価の有機基を示し、複数存在するＸ^２は同一でも異なっていてもよい。）
で表される化合物などの分子内に２つの１級アミノ基および該１級アミノ基以外の窒素原子を有するジアミン；
下記式（Ｄ−ＩＩＩ）

(In Formula (D-II), R ⁶ represents a divalent organic group having a ring structure containing a nitrogen atom selected from pyridine, pyrimidine, triazine, piperidine and piperazine, and X ² represents a divalent organic group, respectively. A plurality of X ² may be the same or different.)
A diamine having two primary amino groups and a nitrogen atom other than the primary amino group in a molecule such as a compound represented by:
The following formula (D-III)

(In the formula (D-III), R ⁷ represents a divalent linking group selected from —O—, —COO—, —OCO—, —NHCO—, —CONH— and —CO—, and R ⁸ represents a steroid. A monovalent organic group having a skeleton or a group selected from a skeleton, a trifluoromethylphenyl group, a trifluoromethoxyphenyl group and a fluorophenyl group, or an alkyl group having 6 to 30 carbon atoms.)
Monosubstituted phenylenediamines such as compounds represented by:
The following formula (D-IV)

(In the formula (D-IV), R ⁹ represents a hydrocarbon group having 1 to 12 carbon atoms, and a plurality of R ⁹ may be the same or different, and p represents 1 to 3 respectively. And q is an integer of 1 to 20.)
Diaminoorganosiloxanes such as compounds represented by:
The following formulas (D-1) to (D-5)

(Y in the formula (D-4) is an integer of 2 to 12, and z in the formula (D-5) is an integer of 1 to 5.)
And the like, and the like. These diamines can be used alone or in combination of two or more.
In addition to the compound represented by the above formula (A), the diamine used for synthesizing the polyamic acid in the present invention includes, as other diamines, p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4. '-Diaminodiphenyl sulfide, 1,5-diaminonaphthalene, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-ditrifluoromethyl-4,4'-diaminobiphenyl, 2,7-diamino Fluorene, 4,4′-diaminodiphenyl ether, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 9,9-bis (4-aminophenyl) fluorene, 2,2-bis [4- ( 4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 4, 4 ′-(p-phenylenediisopropylidene) bisaniline, 4,4 ′-(m-phenylenediisopropylidene) bisaniline, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4- Aminophenoxy) biphenyl, 1,4-diaminocyclohexane, 4,4′-methylenebis (cyclohexylamine), 1,3-bis (aminomethyl) cyclohexane, each of the above formulas (D-1) to (D-5) 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminoacridine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N, N′-bis 4-aminophenyl) -benzidine, N, N′-bis (4-aminophenyl) -N, N′-dimethylbenzidine, the following formula (D-6) among the compounds represented by the above formula (DI) )

Of the compounds represented by formula (D-II), the following formula (D-7)

Of the compounds represented by formula (D-III), dodecanoxy-2,4-diaminobenzene, pentadecanoxy-2,4-diaminobenzene, hexadecanoxy-2,4-diaminobenzene, octadecanoxy- 2,4-diaminobenzene, dodecanoxy-2,5-diaminobenzene, pentadecanoxy-2,5-diaminobenzene, hexadecanoxy-2,5-diaminobenzene, octadecanoxy-2,5-diaminobenzene, the following formula (D-8) ~ (D-16)

And at least one selected from the group consisting of 1,3-bis (3-aminopropyl) -tetramethyldisiloxane among the compounds represented by the formula (VI) "Other specific diamine" is preferred.
The diamine used for synthesizing the polyamic acid in the present invention preferably contains 1 mol% or more of the compound represented by the above formula (A) with respect to the total diamine, and contains 5 to 50 mol%. More preferably, it is more preferably 10 to 30 mol%.
The diamine used for synthesizing the polyamic acid in the present invention preferably contains 20 mol% or more, and more preferably contains 50 to 70 mol% of the other specific diamine as described above with respect to the total diamine. preferable.

<Synthesis of polyamic acid>
The polyamic acid in the present invention can be synthesized by reacting the tetracarboxylic dianhydride as described above with a diamine containing the compound represented by the above formula (A).
The proportion of tetracarboxylic dianhydride and diamine used in the polyamic acid synthesis reaction is such that the acid anhydride group of tetracarboxylic dianhydride is 0.5 to 1 equivalent to 1 equivalent of amino group contained in the diamine. A ratio of 2 equivalents is preferable, and a ratio of 0.7 to 1.2 equivalents is more preferable.
The polyamic acid synthesis reaction is preferably performed in an organic solvent, preferably at a temperature of -20 to 150 ° C, more preferably at a temperature of 0 to 100 ° C, preferably 0.5 to 240 hours, more preferably 2 to 12. Done for hours. The organic solvent is not particularly limited as long as it can dissolve the synthesized polyamic acid. For example, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide, γ- Examples include aprotic polar solvents such as butyrolactone, tetramethylurea and hexamethylphosphortriamide; phenolic solvents such as m-cresol, xylenol, phenol and halogenated phenol. The amount of organic solvent used (a) is such that the total amount (b) of tetracarboxylic dianhydride and diamine is 0.1 to 30% by weight based on the total amount (a + b) of the reaction solution. Is preferred. In addition, when using an organic solvent and the below-mentioned poor solvent together here, the usage-amount (a) of the said organic solvent should be understood as showing the total amount of an organic solvent and a poor solvent.

For the organic solvent, alcohol, ketone, ester, ether, halogenated hydrocarbon, hydrocarbon and the like, which are poor solvents for polyamic acid, can be used in combination as long as the polyamic acid to be produced does not precipitate. Specific examples of the poor solvent include, for example, methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, ethylene glycol monomethyl ether, ethyl lactate, butyl lactate, Acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, diethyl oxalate, diethyl malonate, diethyl ether, ethylene glycol methyl ether, ethylene Glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol-n- Chill ether, ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, tetrahydrofuran, dichloromethane, 1,2-dichloroethane, 1 , 4-dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene, hexane, heptane, octane, benzene, toluene, xylene, isoamylpropionate, isoamylisobutyrate, diisopentyl ether and the like.
When the organic solvent and the poor solvent described below are used in combination, the use ratio of the poor solvent is preferably 50% by weight or less, more preferably 20% by weight or less, based on the total of the organic solvent and the poor solvent. More preferably 10% by weight or less.

  As described above, a reaction solution obtained by dissolving polyamic acid is obtained. This reaction solution may be used as it is for the preparation of the liquid crystal aligning agent, may be used for the preparation of the liquid crystal aligning agent after isolating the polyamic acid contained in the reaction solution, or the isolated polyamic acid was purified. You may use for preparation of a liquid crystal aligning agent. Polyamic acid can be isolated by pouring the reaction solution into a large amount of poor solvent to obtain a precipitate, and drying the precipitate under reduced pressure, or by distilling the reaction solution under reduced pressure using an evaporator. it can. Further, the polyamic acid can be purified by a method of dissolving the polyamic acid again in an organic solvent and then precipitating with a poor solvent, or a method of performing the step of distilling under reduced pressure with an evaporator once or several times.

<Imidized polymer>
The imidized polymer in the present invention can be obtained by dehydrating and ring-closing the polyamic acid obtained as described above.
The imidized polymer in the present invention may be a completely imidized product in which all of the amic acid structure of the polyamic acid is dehydrated and closed, or may be a combination of an amic acid structure and an imide ring. The imidation rate of the imidized polymer in the present invention is preferably 40% or more, more preferably 80% or more. Here, the “imidization rate” is a numerical value representing the ratio of the number of imide rings to the total of the number of amic acid structures and the number of imide rings in the polymer, expressed as a percentage. At this time, a part of the imide ring may be an isoimide ring.
The dehydration ring closure reaction of polyamic acid is, for example, (i) a method of heating polyamic acid,
(Ii) A polyamic acid can be dissolved in an organic solvent, a dehydrating agent and a dehydrating ring-closing catalyst are added to the solution, and heating is performed as necessary.
The reaction temperature in the method of heating the polyamic acid (i) is preferably 50 to 200 ° C, more preferably 60 to 170 ° C. When the reaction temperature is less than 50 ° C., the dehydration ring-closing reaction does not proceed sufficiently, and when the reaction temperature exceeds 200 ° C., the molecular weight of the imidized polymer obtained may decrease. The reaction time is preferably 0.5 to 24 hours, more preferably 2 to 12 hours.
In the method (ii) of adding a dehydrating agent and a dehydrating ring-closing catalyst to the polyamic acid solution, for example, an acid anhydride such as acetic anhydride, propionic anhydride, or trifluoroacetic anhydride can be used. . It is preferable that the usage-amount of a dehydrating agent shall be 0.01-20 mol with respect to 1 mol of repeating units of a polyamic acid. Moreover, as a dehydration ring closure catalyst, tertiary amines, such as a pyridine, a collidine, a lutidine, a triethylamine, can be used, for example. However, it is not limited to these. The amount of the dehydration ring closure catalyst used is preferably 0.01 to 10 moles per mole of the dehydrating agent used. Examples of the organic solvent used in the dehydration ring-closing reaction include the organic solvents exemplified as those used for the synthesis of polyamic acid. The reaction temperature of the dehydration ring closure reaction is preferably 0 to 180 ° C, more preferably 10 to 150 ° C. The reaction time is preferably 0.5 to 24 hours, more preferably 2 to 12 hours.

  The imidized polymer obtained in the above method (i) may be used for the preparation of a liquid crystal aligning agent as it is, or may be used for the preparation of a liquid crystal aligning agent after purifying the obtained imidized polymer. . On the other hand, in the method (ii), a reaction solution containing an imidized polymer is obtained. This reaction solution may be directly used for the preparation of the liquid crystal aligning agent, or may be used for the preparation of the liquid crystal aligning agent after removing the dehydrating agent and the dehydrating ring-closing catalyst from the reaction solution. After separating, it may be used for preparing a liquid crystal aligning agent, or the isolated imidized polymer may be purified and then used for preparing a liquid crystal aligning agent. In order to remove the dehydrating agent and the dehydrating ring-closing catalyst from the reaction solution, for example, a method such as solvent replacement can be applied. Isolation and purification of the imidized polymer can be performed by performing the same operations as described above as the method for isolating and purifying the polyamic acid.

<End-modified polymer>
The polyamic acid and the imidized polymer may be a terminal-modified polymer having a controlled molecular weight. Such a terminal-modified polymer can be synthesized by adding an appropriate molecular weight regulator such as acid monoanhydride, monoamine compound, monoisocyanate compound to the reaction system when synthesizing the polyamic acid. .
Here, as the acid monoanhydride, for example, maleic anhydride, phthalic anhydride, itaconic anhydride, n-decyl succinic anhydride, n-dodecyl succinic anhydride, n-tetradecyl succinic anhydride , N-hexadecyl succinic anhydride and the like. Examples of the monoamine compound include aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, n-undecylamine, n -Dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecylamine, n-octadecylamine, n-eicosylamine . Examples of the monoisocyanate compound include phenyl isocyanate and naphthyl isocyanate.
The use ratio of the molecular weight modifier is preferably 10 parts by weight or less, more preferably 5 parts by weight with respect to 100 parts by weight of the total of tetracarboxylic dianhydride and diamine used when the polyamic acid is synthesized. Or less.

<Solution viscosity>
The polyamic acid or imidized polymer obtained as described above preferably has a solution viscosity of 20 to 800 mPa · s, when it is made into a solution having a concentration of 10% by weight, and preferably has a solution viscosity of 30 to 500 mPa · s. More preferably, it has a solution viscosity.
The solution viscosity (mPa · s) of the above polymer is E for a polymer solution having a concentration of 10% by weight prepared using a good solvent for the polymer (for example, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.). It is a value measured at 25 ° C. using a mold rotational viscometer.

<Other ingredients>
The liquid crystal aligning agent of the present invention contains at least one polymer selected from the group consisting of the above polyamic acid and its imidized polymer as an essential component, but the effects and advantages of the present invention are other than that. Other components may be contained as long as they are not impaired. Examples of such other components include other polymers, compounds having at least one epoxy group in the molecule (hereinafter referred to as “epoxy compound”), and functional silane compounds.
Examples of the other polymer include polyamic acid obtained by reacting, for example, polyorganosiloxane, tetracarboxylic dianhydride and a diamine not containing the compound represented by the above formula (A) (hereinafter referred to as “other polyamic acid”). Acid ") and imidized polymers thereof (hereinafter referred to as" other imidized polymers "), polyamic acid esters, polyesters, polyamides, cellulose derivatives, polyacetals, polystyrene derivatives, poly (styrene-phenylmaleimide) derivatives. And poly (meth) acrylate. Among these, other polyamic acids or other imidized polymers are preferable from the viewpoint of excellent varnish properties and electrical characteristics, and other polyamic acids are more preferable.
The proportion of the other polymer used in the liquid crystal aligning agent of the present invention is the sum of the polymers (polyamic acid obtained by reacting a tetracarboxylic dianhydride and a diamine containing a compound represented by the above formula (A). And the imidized polymer and the total of other polymers, the same shall apply hereinafter)), preferably 80% by weight or less, more preferably 50% by weight or less, and further 20% by weight or less. It is preferable.

  The said epoxy compound can be contained in the liquid crystal aligning agent of this invention from a viewpoint of improving the adhesiveness with respect to the substrate surface of the liquid crystal aligning film formed. Examples of such epoxy compounds include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, and 1,6-hexane. Diol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, N, N, N ′, N′— Tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ′, N′-tetraglycidyl-4,4 ′ Diaminodiphenylmethane, N, N-diglycidyl - benzylamine, N, N-diglycidyl - and aminomethyl cyclohexane, may be mentioned as being preferred. The use ratio of the epoxy compound is preferably 40 parts by weight or less, and more preferably 0.1 to 30 parts by weight with respect to 100 parts by weight of the total polymer.

Examples of the functional silane compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl)- 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyl Trimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4 7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N- Benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis ( Examples thereof include oxyethylene) -3-aminopropyltrimethoxysilane and N-bis (oxyethylene) -3-aminopropyltriethoxysilane.
The blending ratio of the functional silane compound is preferably 2 parts by weight or less, and more preferably 0.2 parts by weight or less, with respect to 100 parts by weight of the total polymer.

<Liquid crystal aligning agent>
The liquid crystal aligning agent of the present invention preferably contains at least one polymer selected from the group consisting of the polyamic acid and its imidized polymer as described above, and other optional components, preferably dissolved in an organic solvent. , Containing.
As an organic solvent which comprises the liquid crystal aligning agent of this invention, the solvent illustrated as what is used for the synthesis reaction of a polyamic acid can be mentioned. Here, the poor solvent illustrated as what can be used together in the synthesis reaction of a polyamic acid can also be selected suitably, and can be used together.
Particularly preferable organic solvents used in the liquid crystal aligning agent of the present invention include, for example, N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N, N-dimethylformamide, N, N-dimethylacetamide, 4- Hydroxy-4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n- Propyl ether, ethylene glycol-i-propyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol Dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, isoamyl propionate, isoamyl isobutyrate, diisopentyl ether and the like. These can be used alone or in admixture of two or more.

A particularly preferable solvent composition in the liquid crystal aligning agent of the present invention is a composition obtained by combining the above-mentioned solvents, in which no polymer is precipitated in the liquid crystal aligning agent, and the surface tension of the aligning agent is 25 to 40 mN / m. The composition is in the range.
The solid content concentration in the liquid crystal aligning agent of the present invention (the ratio of the total weight of components other than the solvent in the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) is selected in consideration of viscosity, volatility, Preferably it is the range of 1-10 weight%. That is, the liquid crystal aligning agent of the present invention is applied to the substrate surface, and then the solvent is removed to form a coating film that becomes a liquid crystal aligning film. The liquid crystal aligning agent has a solid content concentration of 1% by weight. If it is less than 10% by weight, it may be difficult to obtain a good liquid crystal alignment film because the film thickness of this coating film is too small. If the thickness is excessive, it may be difficult to obtain a good liquid crystal alignment film, and the viscosity of the liquid crystal aligning agent may increase, resulting in poor coating characteristics.
The particularly preferable solid content concentration range varies depending on the method used when applying the liquid crystal aligning agent to the substrate. For example, when coating is performed by a spinner method, a solid content concentration of 1.5 to 4.5% by weight is particularly preferable. When coating is performed by a printing method, it is particularly preferable that the solid content concentration is in the range of 3 to 9% by weight, and thereby the solution viscosity of the liquid crystal aligning agent is in the range of 12 to 50 mPa · s. When the coating is performed by an ink jet method, it is particularly preferable that the solid content concentration is in the range of 1 to 5% by weight, and thereby the solution viscosity of the liquid crystal aligning agent is in the range of 3 to 15 mPa · s.
The temperature at the time of preparing the liquid crystal aligning agent of this invention becomes like this. Preferably it is 0-100 degreeC, More preferably, it is 20-60 degreeC.

<Liquid crystal display element>
The liquid crystal display element of the present invention comprises a liquid crystal alignment film formed from the liquid crystal aligning agent of the present invention as described above.
The liquid crystal display element of the present invention can be produced, for example, by the following method.
(1) First, the liquid crystal alignment film of the present invention is applied onto a pair of substrates, and the solvent is removed to form a coating film. Here, when the display mode of the liquid crystal display element to be manufactured is a vertical electric field system such as a TN type, an STN type, or a VA type, two substrates on which a transparent conductive film patterned on one side is provided. Are used as a pair of substrates. On the other hand, when the display mode of the liquid crystal display element to be manufactured is a horizontal electric field method, a pair of a substrate provided with a transparent conductive film having a comb-like pattern and a substrate not having a transparent conductive film is used. Used as a substrate.
In any of the above cases, when the substrate has a transparent conductive film, the liquid crystal aligning agent is applied to the surface of the substrate having the transparent conductive film. As the substrate, for example, glass such as float glass or soda glass; a transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, poly (cycloaliphatic olefin) can be used. Examples of the transparent conductive film provided on one surface of the substrate include an NESA film (registered trademark of PPG, USA) made of tin oxide (SnO ₂ ), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ), and the like. Can be used. In addition, in order to obtain these patterned transparent conductive films, a method of forming a pattern by a photo-etching method after forming a transparent conductive film without a pattern, and a mask having a desired pattern when forming the transparent conductive film. For example, a method of directly forming a patterned transparent conductive film can be employed.
The liquid crystal aligning agent is applied onto the substrate by an appropriate application method such as a roll coater method, a spinner method, a printing method, or an ink jet method. When applying the liquid crystal aligning agent, in order to further improve the adhesion between the substrate surface and the transparent conductive film and the coating film, a functional silane compound, a functional titanium compound, or the like is applied in advance to the coated surface of the substrate. You may keep it.
In the case where the liquid crystal display element to which the liquid crystal aligning agent of the present invention is applied is a VA type liquid crystal display element, for example, a projecting construction as described in Patent Document 7 (Japanese Patent Laid-Open No. 2002-327058). A viewing angle characteristic may be improved by applying a liquid crystal aligning agent after forming an object on a substrate.

After the application, preheating (pre-baking) is preferably performed for the purpose of preventing dripping of the applied alignment agent. The pre-baking temperature is preferably 30 to 200 ° C, more preferably 40 to 150 ° C, and particularly preferably 40 to 100 ° C. The pre-bake time is preferably 0.1 to 10 minutes, more preferably 0.5 to 3 minutes. Thereafter, a baking (post-baking) step is performed for the purpose of completely removing the solvent. The post-bake temperature is preferably 80 to 300 ° C, more preferably 120 to 250 ° C. The post-bake time is preferably 5 to 180 minutes, more preferably 10 to 100 minutes.
Thus, the liquid crystal aligning agent of this invention forms the coating film used as a liquid crystal aligning film by removing an organic solvent after application | coating. At this time, when the polymer contained in the liquid crystal aligning agent of the present invention is a polyamic acid or an imidized polymer in which an amic acid structure remains, dehydration of the amic acid structure is performed by further heating after the coating film is formed. It is good also as a coating film which made the ring closure progress further and was imidized more.
The film thickness of the formed coating film is preferably 0.001-1 μm, more preferably 0.005-0.5 μm.

(2) When the display mode of the liquid crystal display element to be manufactured is the VA type, the coating film formed as described above can be used as a liquid crystal alignment film as it is. The rubbing process described may be performed.
On the other hand, when the display mode of the liquid crystal display element to be manufactured is a vertical electric field method other than the VA type or a horizontal electric field method, for example, nylon, rayon, cotton or the like on the formed coating film surface A rubbing treatment is performed by rubbing in a certain direction with a roll wound with a cloth made of the above fibers. Thereby, the orientation ability of a liquid crystal molecule is provided to a coating film, and it becomes a liquid crystal aligning film. Furthermore, a part of the liquid crystal alignment film as shown in, for example, Patent Document 8 (Japanese Patent Laid-Open No. 6-222366) or Patent Document 9 (Japanese Patent Laid-Open No. 6-281937) is applied to the coating film after rubbing treatment. Or a part of the surface of the liquid crystal alignment film as disclosed in Patent Document 10 (Japanese Patent Laid-Open No. 5-107544) By forming a resist film on the top and performing a rubbing treatment in a direction different from the previous rubbing treatment, and then removing the resist film so that the liquid crystal alignment film has different liquid crystal alignment capabilities for each region, It is possible to improve the visibility characteristics of the obtained liquid crystal display element.

(3) When a pair of substrates on which a liquid crystal alignment film is formed as described above is manufactured and rubbed, the two rubbing directions in each liquid crystal alignment film are orthogonal or antiparallel. A liquid crystal cell is configured by disposing a liquid crystal in a gap (cell gap) in which the substrates are arranged to face each other so that the liquid crystal alignment film faces each other. For example, the following two methods can be used to arrange the liquid crystal in the gap between the pair of substrates.
The first method is a conventionally known method. First, two substrates are arranged to face each other through a gap (cell gap) so that the respective liquid crystal alignment films are opposed to each other, and the peripheral portions of the two substrates are bonded using a sealant, and the substrate surface and the sealant are bonded. A liquid crystal cell can be manufactured by injecting and filling liquid crystal into the cell gap partitioned by the above, and then sealing the injection hole.
The second method is a method called an ODF (One Drop Fill) method. For example, an ultraviolet light curable sealing material is applied to a predetermined location on one of the two substrates on which the liquid crystal alignment film is formed, and liquid crystal is dropped on the liquid crystal alignment film surface. The other substrate is bonded so as to face each other, and then the entire surface of the substrate is irradiated with ultraviolet light to cure the sealant, whereby a liquid crystal cell can be manufactured.
In any case, it is desirable to remove the flow alignment at the time of filling the liquid crystal by heating the liquid crystal cell to a temperature at which the liquid crystal used has an isotropic phase and then gradually cooling it to room temperature.
And the liquid crystal display element of this invention can be obtained by bonding a polarizing plate on the outer surface of a liquid crystal cell.

Here, as the sealing agent, for example, an epoxy resin containing a curing agent and aluminum oxide spheres as a spacer can be used.
Examples of the liquid crystal include nematic liquid crystal and smectic liquid crystal. Among them, nematic liquid crystal is preferable. For example, Schiff base liquid crystal, azoxy liquid crystal, biphenyl liquid crystal, phenylcyclohexane liquid crystal, ester liquid crystal, terphenyl liquid crystal, biphenyl. Cyclohexane liquid crystals, pyrimidine liquid crystals, dioxane liquid crystals, bicyclooctane liquid crystals, cubane liquid crystals, and the like can be used. Further, cholesteric liquid crystals such as cholestyl chloride, cholesteryl nonate, and cholesteryl carbonate; chiral agents such as those sold under the trade names “C-15” and “CB-15” (manufactured by Merck & Co., Inc.). A ferroelectric liquid crystal such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate may be added and used.
As a polarizing plate bonded to the outer surface of the liquid crystal cell, a polarizing film or an H film in which a polarizing film called an “H film” that absorbs iodine while stretching and aligning polyvinyl alcohol is sandwiched between protective films of cellulose acetate The polarizing plate which consists of itself can be mentioned.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. In the following examples, a commercially available product (manufactured by Wako Pure Chemical Industries, Ltd.) was used as it was as tetrahydroabietic acid. Moreover, the solution viscosity of the polymer and the imidation ratio of the imidized polymer in the following Examples and Synthesis Examples were measured by the following methods, respectively.
[Solution viscosity of polymer]
The solution viscosity of the polymer was measured at 25 ° C. using an E-type viscometer for the polymer solution indicated in each example and synthesis example.
[Imidation rate of imidized polymer]
The imidized polymer was dried under reduced pressure at room temperature, dissolved in deuterated dimethyl sulfoxide, and obtained from ¹ H-NMR measured at room temperature using tetramethylsilane as a reference substance, and the following formula (i) was used.

Imidation rate (%) = (1-A ¹ / A ² × α) × 100 (i)

A ¹ : Peak area derived from protons of NH group appearing near 10 ppm A ² : Peak area derived from other protons α: Other protons relative to one proton of NH group in the precursor (polyamic acid) of imidized polymer Number ratio

<Synthesis of Compound Represented by Formula (A)>
Example 1 (Synthesis of a compound represented by the above formula (A-1) (hereinafter referred to as “compound (A-1)”))
A 500 mL eggplant flask equipped with a reflux tube was charged with 31 g of tetrahydroabietic acid, 200 mL of thionyl chloride and 0.1 mL of N, N-dimethylformamide, and reacted at 80 ° C. with stirring for 1 hour. After completion of the reaction, thionyl chloride was removed under reduced pressure, and 200 mL of methylene chloride was added. The organic layer is taken, washed 3 times with water, dried over magnesium sulfate and concentrated, and then 200 mL of tetrahydrofuran is added (this is referred to as “reaction solution (1)”).
Separately, 20 g of 2,5-dinitrophenol, 15 g of potassium carbonate, 1.0 g of tetrabutylammonium bromide, 100 mL of tetrahydrofuran and 200 mL of water were added to a 1 L three-necked flask equipped with a dropping funnel and a thermometer, and ice-cooled. The above reaction liquid (1) was added dropwise over 1 hour or longer, and the reaction was continued by stirring for 2 hours under ice cooling. After completion of the reaction, 1 L of ethyl acetate was added for extraction, and the organic layer was washed 3 times with water, dried over magnesium sulfate, concentrated, and recrystallized with ethanol to obtain the following formula (A-1-1).

35 g of a compound represented by the following (hereinafter referred to as “compound (A-1-1)”) was obtained as pale yellow crystals.
Next, 35 g of the compound (A-1-1) obtained above, 170 g of tin chloride dihydrate and 300 mL of ethanol were charged into a 1 L three-necked flask equipped with a thermometer and a nitrogen introduction tube, and reacted at 70 ° C. for 1 hour. Went. After completion of the reaction, the reaction mixture was neutralized by adding a saturated aqueous sodium hydrogen carbonate solution, ethyl acetate was added, and the precipitate was removed by filtration. The filtrate was washed 3 times with water and then the solvent was removed to obtain 24 g of a pale yellow compound (A-1).
Example 2 (Synthesis of a compound represented by the above formula (A-2) (hereinafter referred to as “compound (A-2)”))
The reaction was conducted in the same manner as in Example 1 except that 2,4-dinitrophenol was used instead of 2,5-dinitrophenol, to obtain 22 g of compound (A-2).
Example 3 (Synthesis of a compound represented by the above formula (A-3) (hereinafter referred to as “compound (A-3)”))
A 1 L three-necked flask equipped with a thermometer and a nitrogen inlet tube was charged with 31 g of tetrahydroabietic acid, 22 g of 2,4-dinitrobenzyl chloride, 28 g of potassium carbonate, 3.3 g of sodium iodide and 300 mL of 1-methyl-2-pyrrolidone. The reaction was carried out at 100 ° C. for 3 hours. After completion of the reaction, 1 L of toluene was added to the reaction mixture for extraction, and the organic layer was washed three times with water, dried over magnesium sulfate, concentrated, and recrystallized with ethanol to obtain the following formula (A-3- 1)

40 g of a compound represented by the following (hereinafter referred to as “compound (A-3-1)”) was obtained as pale yellow crystals.
Subsequently, 40 g of the compound (A-3-1) obtained above, 190 g of tin chloride dihydrate and 400 mL of ethanol were charged into a 1 L three-necked flask equipped with a thermometer and a nitrogen introduction tube, and reacted at 70 ° C. for 1 hour. Went. After completion of the reaction, the reaction mixture was neutralized by adding a saturated aqueous sodium hydrogen carbonate solution, ethyl acetate was added, and the precipitate was removed by filtration. The filtrate was washed 3 times with water, and then the solvent was removed to obtain 25 g of a pale yellow compound (A-3).
Example 4 (Synthesis of a compound represented by the above formula (A-4) (hereinafter referred to as “compound (A-4)”))
The same procedure as in Example 3 was conducted, except that 3,5-dinitrobenzyl chloride was used instead of 2,4-dinitrobenzyl chloride, to obtain 26 g of compound (A-4).

<Synthesis of imidized polymer>
Example 5
5.7 g of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride, 2.2 g of p-phenylenediamine as diamine and 2. of the compound (A-1) obtained in Example 1 above. 1 g was dissolved in 40 g of N-methyl-2-pyrrolidone (NMP) and reacted at 60 ° C. for 6 hours. A small amount of the obtained polyamic acid solution was taken, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 100 mPa · s.
Next, 50 g of NMP was added to the obtained polyamic acid solution, 2.0 g of pyridine and 2.6 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration ring closure reaction, the solvent in the system was replaced with new γ-butyrolactone (the pyridine and acetic anhydride used for the dehydration ring closure reaction were removed from the system in this operation. The same applies hereinafter). About 60 g of a solution containing 15% by weight of imidized polymer (PI-1) having a rate of about 50% was obtained. A small amount of this solution was collected, and γ-butyrolactone was added to measure the solution viscosity as a solution having an imidized polymer concentration of 10% by weight of 100 mPa · s.
Example 6
5.7 g of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride, 2.2 g of p-phenylenediamine as diamine and 2.1 g of the compound (A-2) obtained in Example 2 above Was dissolved in 40 g of N-methyl-2-pyrrolidone (NMP) and reacted at 60 ° C. for 6 hours. A small amount of the obtained polyamic acid solution was collected, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 90 mPa · s.
Next, 50 g of NMP was added to the obtained polyamic acid solution, 2.0 g of pyridine and 2.6 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration cyclization reaction, the solvent in the system was replaced with new γ-butyrolactone to obtain about 60 g of a solution containing 15% by weight of an imidized polymer (PI-2) having an imidation ratio of about 50%. . A small amount of this solution was taken, and γ-butyrolactone was added thereto, and the solution viscosity measured as a solution having an imidized polymer concentration of 10% by weight was 90 mPa · s.

Example 7
5.7 g of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as tetracarboxylic dianhydride, 2.2 g of p-phenylenediamine as diamine and 2.2 g of the compound (A-3) obtained in Example 3 above Was dissolved in 40 g of N-methyl-2-pyrrolidone (NMP) and reacted at 60 ° C. for 6 hours. A small amount of the obtained polyamic acid solution was taken, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 100 mPa · s.
Next, 50 g of NMP was added to the obtained polyamic acid solution, 2.0 g of pyridine and 2.6 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration cyclization reaction, the solvent in the system was replaced with new γ-butyrolactone to obtain about 60 g of a solution containing 15% by weight of an imidized polymer (PI-3) having an imidization ratio of about 50%. . A small amount of this solution was collected, and γ-butyrolactone was added to measure the solution viscosity as a solution having an imidized polymer concentration of 10% by weight of 100 mPa · s.
Example 8
5.7 g of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as tetracarboxylic dianhydride, 2.2 g of p-phenylenediamine as diamine and 2.2 g of the compound (A-4) obtained in Example 4 above Was dissolved in 40 g of N-methyl-2-pyrrolidone (NMP) and reacted at 60 ° C. for 6 hours. A small amount of the obtained polyamic acid solution was collected, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 120 mPa · s.
Next, 50 g of NMP was added to the obtained polyamic acid solution, 2.0 g of pyridine and 2.6 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration cyclization reaction, the solvent in the system was replaced with new γ-butyrolactone to obtain about 60 g of a solution containing 15% by weight of an imidized polymer (PI-4) having an imidation ratio of about 50%. . A small amount of this solution was collected, and γ-butyrolactone was added thereto, and the solution viscosity measured as a solution having an imidized polymer concentration of 10% by weight was 120 mPa · s.

Example 9
5.7 g of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as tetracarboxylic dianhydride, 2.2 g of p-phenylenediamine as diamine and 2.2 g of the compound (A-4) obtained in Example 4 above Was dissolved in 40 g of N-methyl-2-pyrrolidone (NMP) and reacted at 60 ° C. for 6 hours. A small amount of the obtained polyamic acid solution was collected, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 120 mPa · s.
Next, 50 g of NMP was added to the obtained polyamic acid solution, 4.2 g of pyridine and 5.4 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration cyclization reaction, the solvent in the system was replaced with new γ-butyrolactone to obtain about 60 g of a solution containing 15% by weight of an imidized polymer (PI-5) having an imidization ratio of about 80%. . A small amount of this solution was taken, and γ-butyrolactone was added to measure the viscosity of the solution as a solution having an imidized polymer concentration of 10% by weight of 130 mPa · s.
<Synthesis of other polyamic acids>
Synthesis example 1
200 g (1.0 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride as tetracarboxylic dianhydride and 210 g of 2,2′-dimethyl-4,4′-diaminobiphenyl as diamine (1. 0 mol) is dissolved in a mixed solvent consisting of 370 g of N-methyl-2-pyrrolidone and 3,300 g of γ-butyrolactone, and reacted at 40 ° C. for 3 hours, so that 10 weight of other polyamic acid (PA-1) is obtained. About 3,700 g of a solution containing% was obtained. The solution viscosity of this polyamic acid solution was 160 mPa · s.

Example 10
<Preparation of liquid crystal aligning agent>
Γ-butyrolactone (BL), N-methyl-2-pyrrolidone (NMP) and butyl cellosolve (BC) were added to the solution containing the imidized polymer (PI-1) obtained in Example 5 above, and the solvent composition was BL : NMP: BC = 71: 17: 12 (weight ratio), a solid content concentration of 4% by weight. A liquid crystal aligning agent was prepared by filtering this solution using a filter having a pore size of 1 μm.
Various evaluation was performed as follows using this liquid crystal aligning agent. The evaluation results are shown in Table 1.
<Evaluation of printability>
Using the liquid crystal aligning agent prepared above on a transparent electrode surface of a glass substrate with a transparent electrode made of an ITO film, using a liquid crystal alignment film printer (manufactured by Nissha Printing Co., Ltd., model “Angstromer S40L-532”). And applied. At this time, the dropping amount of the liquid crystal aligning agent onto the anilox roll was 25 drops (about 0.25 g). This condition is a severe condition as compared with a drop amount of 30 drops (about 0.3 g) that is usually employed when applying the liquid crystal alignment film.
Next, the coated substrate was heated (pre-baked) at 80 ° C. for 1 minute to remove the solvent, and then heated (post-baked) at 180 ° C. for 10 minutes to form a coating film having a thickness of 800 nm. When this coating film was visually observed for the presence of repellency and coating unevenness, neither printing unevenness nor pinholes were observed, and the printability of the liquid crystal aligning agent was “good”.
<Manufacture of vertical liquid crystal display elements>
The liquid crystal aligning agent prepared above is applied onto a transparent conductive film made of an ITO film provided on one side of a glass substrate having a thickness of 1 mm by a spinner, and heated for 1 minute on an 80 ° C. hot plate and then in an oven at 200 ° C. A coating film (liquid crystal alignment film) having a thickness of 0.08 μm was formed by heating for 60 minutes. This operation was repeated to obtain a pair (two) of glass substrates having a liquid crystal alignment film on the transparent conductive film.
For the glass substrate having the pair of liquid crystal alignment films, after applying an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 3.5 μm to the outer edges of the surfaces having the liquid crystal alignment films, the liquid crystal alignment film surfaces face each other. The adhesive was cured by overlapping and pressing. Next, a negative type liquid crystal (MLC-6608, manufactured by Merck & Co., Inc.) is injected into the gap between the substrates from the liquid crystal injection port, and then the liquid crystal injection port is sealed with an acrylic photo-curing adhesive. A vertical liquid crystal display element was manufactured by laminating polarizing plates on both sides.

<Evaluation of liquid crystal alignment>
The vertical liquid crystal display device manufactured above was observed with an optical microscope for the presence or absence of abnormal domains when the voltage was turned on / off, and the case where no abnormal domains were observed was evaluated as “good” for liquid crystal alignment.
<Evaluation of voltage holding ratio>
For the vertical type liquid crystal display device manufactured as described above, a voltage of 5 V was applied at 60 ° C. with an application time of 60 microseconds and a span of 167 milliseconds, and then the voltage holding ratio after 167 milliseconds from the application release was measured. As a measuring device, VHR-1 manufactured by Toyo Corporation was used. When the voltage holding ratio is 95% or more, it can be said that the voltage holding ratio is “good”.
<Measurement of residual DC voltage>
A DC voltage of 5.0 V was applied for 20 hours at an environmental temperature of 60 ° C. for the vertical liquid crystal display device manufactured above. The voltage (residual DC voltage) remaining in the liquid crystal cell after standing for 15 minutes at room temperature immediately after turning off the DC voltage was determined by a flicker-erasing method. When the residual voltage was 300 mV or less, the residual DC voltage was evaluated as “good”.

Examples 11-13
A liquid crystal aligning agent was prepared and evaluated in the same manner as in Example 10 except that the solution containing the imidized polymer shown in Table 1 was used as the solution containing the polymer. The evaluation results are shown in Table 1.
Example 14
The solution containing the imidized polymer (PI-4) obtained in Example 8 was taken in an amount corresponding to 100 parts by weight in terms of the imidized polymer (PI-4) contained therein, To this was added 20 parts by weight of N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane as an epoxy compound, and γ-butyrolactone (BL), N-methyl-2-pyrrolidone (NMP) and Butyl cellosolve (BC) was added to obtain a solution having a solvent composition of BL: NMP: BC = 71: 17: 12 (weight ratio) and a solid content concentration of 4% by weight. A liquid crystal aligning agent was prepared by filtering this solution using a filter having a pore size of 1 μm.
Various evaluations were performed in the same manner as in Example 10 using this liquid crystal aligning agent. The evaluation results are shown in Table 1.
Example 15
The amount corresponding to 20 parts by weight in terms of the imidized polymer (PI-5) in the solution containing the imidized polymer (PI-5) obtained in Example 9 above, and obtained in Synthesis Example 1 above. A solution containing another polyamic acid (PA-1) is combined with an amount corresponding to 80 parts by weight in terms of another polyamic acid (PI-5), and γ-butyrolactone (BL), N-methyl -2-pyrrolidone (NMP) and butyl cellosolve (BC) were added to obtain a solution having a solvent composition of BL: NMP: BC = 71: 17: 12 (weight ratio) and a solid concentration of 4% by weight. A liquid crystal aligning agent was prepared by filtering this solution using a filter having a pore size of 1 μm.
Various evaluations were performed in the same manner as in Example 10 using this liquid crystal aligning agent. The evaluation results are shown in Table 1.

Example 16
In Example 15, after combining the solution containing the imidized polymer (PI-5) and the solution containing another polyamic acid (PA-1), N, N, N ′, A liquid crystal aligning agent was prepared in the same manner as in Example 15 except that 20 parts by weight of N′-tetraglycidyl-4,4′-diaminodiphenylmethane was added with respect to a total of 100 parts by weight of the polymer. Various evaluations were performed in the same manner as in Example 10 using this liquid crystal aligning agent. The evaluation results are shown in Table 1.

Claims (4)

Tetracarboxylic dianhydride and the following formula (A)

(In formula (A), X is a single bond, a methylene group or an ethylene group.)
A liquid crystal aligning agent comprising at least one polymer selected from the group consisting of a polyamic acid obtained by reacting a diamine containing a compound represented by the formula (I) and an imidized polymer thereof.   A liquid crystal display element comprising a liquid crystal alignment film formed from the liquid crystal alignment agent according to claim 1.   A polyamic acid obtained by reacting a tetracarboxylic dianhydride with a diamine containing a compound represented by the above formula (A) or an imidized polymer thereof.   Compound represented by the above formula (A).