JP5019064B2 - Liquid crystal aligning agent and liquid crystal display element - Google Patents

Description

  The present invention relates to a liquid crystal aligning agent and a liquid crystal display element. More specifically, a liquid crystal aligning agent that provides a liquid crystal alignment film with reduced liquid crystal dropping unevenness and liquid crystal fusion portion unevenness when a liquid crystal dropping method (ODF) is applied in manufacturing a liquid crystal display element, and a liquid crystal aligning film obtained therefrom are provided. The present invention relates to a liquid crystal display element.

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 a 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 so-called TN type (Twisted Nematic) liquid crystal cell is known. In addition, 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 having less viewing angle dependency, and a VA (Vertical Alignment). An optical compensation bend (OCB) type liquid crystal display element that has a small viewing angle dependency and excellent high-speed response of an image screen has been developed (see Patent Documents 1 to 3 and Non-Patent Document 1).
As materials for the liquid crystal alignment film in these liquid crystal display elements, polyimide, polyamide, polyester, and the like are conventionally known, but in particular, polyimide has excellent heat resistance, affinity with liquid crystals, mechanical strength, It is used in many liquid crystal display elements (see Patent Document 4).

In general, in order to manufacture a liquid crystal display element, a step of injecting and filling liquid crystal into a gap (cell gap) between two substrates on which a liquid crystal alignment film is formed is necessary. For filling and filling the liquid crystal, a vacuum filling method in which liquid crystal is filled between substrates of a liquid crystal display element by utilizing a pressure difference between atmospheric pressure and vacuum is generally performed, but a substrate of only 3 to 6 μm is used. Since a considerable amount of time is required for the liquid crystal to flow through the gaps between them, a long time is required for the manufacturing process, and it has been desired to shorten the manufacturing process particularly for large panels.
A liquid crystal dropping method (ODF method) has been developed as a new liquid crystal filling method that solves the problems in the vacuum injection method described above. This is because a required amount of liquid crystal is dropped on a substrate on which a liquid crystal alignment film is formed, and bonded to the other substrate in a vacuum, and then a sealant for sealing the liquid crystal is UV-cured, so that the entire surface of the panel is covered. This is a method capable of filling the liquid crystal (see Patent Document 5). However, in this method, since the liquid crystal is dropped directly on the liquid crystal alignment film, the liquid crystal alignment film is loaded more drastically than in the conventional vacuum injection method, and there are a number of liquid crystal dropping points. And alignment irregularities (generally, the former is called “liquid crystal dripping irregularity” and the latter is called “liquid crystal fusion irregularity”), resulting in a display defect of the liquid crystal display element. was there.
JP-A-4-153622 JP 60-107020 A Japanese Patent Laid-Open No. 11-258605 Japanese Patent Laid-Open No. 62-165628 JP 2001-174829 A JP-A-6-222366 JP-A-6-281937 JP-A-5-107544 SID '94 DIGEST P.I. 927 (1994)

An object of the present invention is to provide a liquid crystal aligning agent that provides a liquid crystal alignment film in which liquid crystal dropping unevenness, liquid crystal fusion portion unevenness and the like are reduced when a liquid crystal dropping method (ODF) is applied in the manufacture of a liquid crystal display element. is there.
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 present invention are as follows.
(A) at least one polymer selected from the group consisting of polyamic acid and imidized polymer thereof, and (b) a compound having 3 or more epoxy groups and 2 or more perfluoroalkyl groups in the molecule. Achieved by containing a liquid crystal aligning agent, and secondly,
This is achieved by a liquid crystal display device comprising a liquid crystal alignment film formed from the liquid crystal alignment agent.

Since the liquid crystal alignment film using the liquid crystal aligning agent of the present invention is excellent in liquid crystal wettability, liquid crystal dropping unevenness, liquid crystal fusion portion unevenness, etc. when a liquid crystal dropping method (ODF) is applied in manufacturing a liquid crystal display element. Gives a liquid crystal aligning agent with reduced. Therefore, in the liquid crystal display element of the present invention having the liquid crystal alignment film formed from the liquid crystal alignment agent, display defects due to liquid crystal dripping unevenness, liquid crystal fusion portion unevenness, and the like do not occur. Such a liquid crystal display element of the present invention can be suitably used for various liquid crystal display elements such as TN type, STN type, VA type, IPS type, OCB type, ferroelectric and antiferroelectric.
The liquid crystal display element of the present invention can be used effectively in various devices, and is used in display devices such as a desk calculator, a wristwatch, a clock, a counting display board, a word processor, a personal computer, and a liquid crystal television.

The liquid crystal aligning agent of the present invention is
(A) at least one polymer selected from the group consisting of polyamic acid and imidized polymer thereof, and (b) a compound having 3 or more epoxy groups and 2 or more perfluoroalkyl groups in the molecule ( Hereinafter, it is referred to as “an epoxy compound having two or more perfluoroalkyl groups”.)
Containing.
Hereinafter, each component which the liquid crystal aligning agent of this invention contains is demonstrated.
(A) Polymer The (a) polymer contained in the liquid crystal aligning agent of the present invention is at least one selected from the group consisting of a polyamic acid and an imidized polymer thereof.
<Polyamic acid>
The polyamic acid can be synthesized by reacting tetracarboxylic dianhydride with diamine.

[Tetracarboxylic dianhydride]
Examples of the tetracarboxylic dianhydride used for synthesizing the polyamic acid used 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- Cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3 ′, 4,4′-dicyclohexyltetracarboxylic dianhydride, 2,3,5 Tricarboxycyclopentylacetic acid dianhydride, 3,5,6-tricarboxynorbornane-2-acetic acid dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic 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, 1,3,3a, 4,5,9b-hexahydro-7-ethyl-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, 1,3,3a, 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-furani ) -Naphtho [1,2-c] -furan-1,3-dione, 5- (2,5-dioxotetrahydrofuranyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 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, the following formula (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 the above, tetracarboxylic dianhydride used for synthesizing the polyamic acid used in the present invention is butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentyl acetate Anhydride, 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, , 3,3a, 4,5,9b-Hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, , 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 2.2.2] -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, 1,4,5,8-Naphthalenetetracarboxylic dianhydride, among the compounds represented by the above formula (TI), the following formulas (T-5) to (T-7)

And the following formula (T-8) among the compounds represented by the formula (T-II)

Liquid crystal formed by using a tetracarboxylic dianhydride containing at least one selected from the group consisting of compounds represented by (hereinafter referred to as “specific tetracarboxylic dianhydride 1”) The alignment film is preferable from the viewpoint of exhibiting good liquid crystal alignment. Examples of the specific tetracarboxylic dianhydride include 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 , 2-Dicarboxylic anhydride , 3,5,6-tricarboxy-2-carboxymethyl norbornane -2: 3,5: 6-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^{2, 6]} undecane -3 , 5,8,10-tetraone, pyromellitic dianhydride and at least one selected from the group consisting of the compounds represented by the above formula (T-5) is more preferable, and 2,3,5-trione is more preferable. Carboxycyclopentyl acetic acid dianhydride is preferred.
The tetracarboxylic dianhydride used for synthesizing the polyamic acid used in the present invention is such that the specific tetracarboxylic dianhydride 1 is 80 mol% or more based on the total tetracarboxylic dianhydride. It is preferable that it is contained, more preferably 90 mol% or more, and particularly preferably 95 mol% or more.

[Diamine]
Examples of the diamine used for synthesizing the polyamic acid used in the present invention include p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylethane, and 4,4. '-Diaminodiphenyl sulfide, 4,4'-diaminodiphenyl 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′-aminophen ) -1,3,3-trimethylindane, 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 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 4,4-bis (4-amino) Enoxy) biphenyl, 9,9-bis (4-aminophenyl) -10-hydroanthracene, 2,7-diaminofluorene, 9,9-dimethyl-2,7-diaminofluorene, 9,9-bis (4-amino) Phenyl) 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 -Phenyleneisopropylidene) 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 '-Dimethylbenzidine;
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 the group consisting of pyridine, pyrimidine, triazine, piperidine and piperazine, and X ¹ represents a divalent organic group. Group.)
A compound represented by:
The following formula (D-II)

(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. The plurality of X ² may be the same or different.)
A compound represented by:
The following formula (D-III)

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

(In formula (D-IV), R ⁹ represents a hydrocarbon group having 1 to 12 carbon atoms, a plurality of R ⁹ may be the same or different, p is an integer of 1 to 3, q Is an integer from 1 to 20.)
Diaminoorganosiloxane 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.)
The compound etc. which are represented by these can be mentioned. These diamines can be used alone or in combination of two or more.
Diamines used for synthesizing the polyamic acid used in the present invention are 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-diaminofluorene, 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, compounds represented by 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'-di (4-aminophenyl) -benzidine, a compound represented by the above formula (DI) Formula of (D-6)

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 (D-IV) Hereinafter, it is preferable to include “specific diamine 1”.
The diamine used for synthesizing the polyamic acid used in the present invention preferably contains 1 mol% or more of the specific diamine 1 as described above with respect to the total diamine, and contains 1 to 50 mol%. More preferably, it is particularly preferable to contain 2 to 20 mol%.
[Synthesis of polyamic acid]
The polyamic acid used in the present invention can be synthesized by reacting the tetracarboxylic dianhydride as described above with a diamine.
The ratio of the tetracarboxylic dianhydride and the diamine compound used for the polyamic acid synthesis reaction is such that the acid anhydride group of the tetracarboxylic dianhydride is 0.1 relative to 1 equivalent of the amino group contained in the diamine compound. A ratio of 5 to 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 at a temperature of −20 to 150 ° C., more preferably 0 to 100 ° C., preferably 0.5 to 120 hours, more preferably 2 to 10 hours. Is called. Here, 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 And aprotic polar solvents such as γ-butyrolactone, tetramethylurea and hexamethylphosphortriamide; and phenol solvents such as m-cresol, xylenol, phenol and halogenated phenol. The amount of organic solvent used (α) is such that the total amount (β) of tetracarboxylic dianhydride and diamine compound is 0.1 to 30% by weight with respect to the total amount (α + β) of the reaction solution. It is preferable. The “amount of organic solvent used” in the above refers to the total amount of the organic solvent and the poor solvent when the organic solvent and the poor solvent described later are used in combination.

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 are used in combination, the proportion of the poor solvent used is preferably 50% by weight or less, more preferably 20% by weight or less, and more preferably 10% by weight based on the total of the organic solvent and the poor solvent. It is preferable that it is below wt%.
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 used in the present invention can be synthesized by dehydrating and ring-closing a polyamic acid obtained by reacting a tetracarboxylic dianhydride and a diamine.
[Tetracarboxylic dianhydride]
Examples of the tetracarboxylic dianhydride used for synthesizing the imidized polymer used in the present invention include the same compounds as the tetracarboxylic dianhydride used for the synthesis of the polyamic acid described above. Of these, alicyclic tetracarboxylic dianhydrides are preferred.
The tetracarboxylic dianhydride used for synthesizing the imidized polymer used in the present invention is 2,3,5-tricarboxycyclopentylacetic acid dianhydride among alicyclic tetracarboxylic dianhydrides. 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-oxa Bicyclo [3.2.1] octane-2,4-dione-6-spiro-3 ′-(tetrahydrofuran-2 ′, 5′-dione), 5- (2,5-dioxotetrahydro-3-furanyl) -3-Methyl-3-cyclohexe -1,2-dicarboxylic anhydride, 3,5,6-tricarboxy-2-carboxynorbornane-2: 3,5: 6-dianhydride and 4,9-dioxatricyclo [5.3.1 .0 ^2,6] at least one selected from the group consisting of undecane -3,5,8,10- tetraone (hereinafter referred to. as "specific tetracarboxylic dianhydride 2") is preferably one containing. As the specific tetracarboxylic dianhydride 2, 2,3,5-tricarboxycyclopentylacetic acid dianhydride is particularly preferable.
The tetracarboxylic dianhydride used for synthesizing the imidized polymer used in the present invention is a specific tetracarboxylic dianhydride 2 as described above, with 80 moles of all tetracarboxylic dianhydrides. % Or more, more preferably 90 mol% or more, and particularly preferably 95 mol% or more.

[Diamine]
Examples of the diamine used for synthesizing the imidized polymer used in the present invention include the same compounds as the diamine used for the synthesis of the polyamic acid described above.
The diamine used for synthesizing the imidized polymer used in the present invention preferably contains a compound represented by the above formula (D-III), and is represented by the above formula (D-III). Of the compounds, dodecanoxy-2,4-diaminobenzene, pentadecanoxy-2,4-diaminobenzene, hexadecanoxy-2,4-diaminobenzene, octadecanoxy-2,4-diaminobenzene, dodecanoxy-2,5-diaminobenzene, pentadecanoxy From the group consisting of -2,5-diaminobenzene, hexadecanoxy-2,5-diaminobenzene, octadecanoxy-2,5-diaminobenzene and the compounds represented by the above formulas (D-8) to (D-16) At least one selected (hereinafter referred to as “specific diamine 2-1”). In addition to specific diamin 2-1 and 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-diaminofluorene, 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-cyclohexanediamine, 4,4′-methylenebis (cyclohexylamine), 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-amino) Phenoxy) biphenyl, compounds represented by the above formulas (D-1) to (D-5), 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminoacridine N, N′-di (4-aminophenyl) -benzidine, N, N′-di (4-aminophenyl) -N, N′-dimethyl-benzidine, a compound represented by the above formula (DI) Among the compounds represented by the above formula (D-6), the compounds represented by the above formula (D-7), and the compounds represented by the above formula (D-IV). ) And at least one selected from the group consisting of 1,3-bis (3-aminopropyl) -tetramethyldisiloxane (hereinafter referred to as “specific diamine 2-2”). ) Is further included.

It is preferable that the diamine used for synthesizing the imidized polymer used in the present invention contains the specific diamine 2-1 as described above in an amount of 0.5 mol% or more based on the total diamine. It is more preferable to contain 1 mol%, and it is particularly preferable to contain 2 to 20 mol%.
Moreover, it is preferable that the diamine used in order to synthesize | combine the imidation polymer used by this invention contains 1 mol% or more of the above specific diamine 2-2 with respect to all the diamine, 50-98. More preferably, it is contained in an amount of 75% to 95% by mole.

[Synthesis of imidized polymer]
The imidized polymer used in the present invention can be synthesized preferably by dehydrating and ring-closing the polyamic acid obtained by reacting the tetracarboxylic dianhydride and diamine as described above. The synthesis of the polyamic acid that is the precursor of the imidized polymer can be performed in the same manner as described above for the synthesis of the polyamic acid used in the present invention.
The dehydration ring closure reaction of the polyamic acid can be carried out by (i) heating the polyamic acid or (ii) dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydrating ring closure catalyst to this solution, and heating as necessary. It can be performed by the method to do.
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 1 to 120 hours, more preferably 2 to 30 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. . The amount of the dehydrating agent used is preferably 0.01 to 20 mol with respect to 1 mol of the polyamic acid repeating unit. 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. In addition, as an organic solvent used for dehydration ring closure reaction, the organic solvent illustrated as what is used for the synthesis | combination of a polyamic acid can be mentioned. And the reaction temperature of dehydration ring closure reaction becomes like this. Preferably it is 0-180 degreeC, More preferably, it is 10-150 degreeC. The reaction time is preferably 0.5 to 30 hours, more preferably 2 to 10 hours.

  The polyimide obtained in the above method (i) may be used for the preparation of the liquid crystal aligning agent as it is, or may be used for the preparation of the liquid crystal aligning agent after purifying the obtained polyimide. 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.

The imidized polymer used in the present invention may be a completely imidized product in which all of the amic acid structure of the polyamic acid as a precursor thereof is dehydrated and cyclized, or only a part of the amic acid structure is dehydrated. The ring may be closed and the amic acid structure and the imide ring may coexist and have a low imidization rate. The imidization rate of the imidized polymer used in the present invention is preferably 40% or more, and more preferably 80% or more. Here, the “imidation rate” is a value representing the ratio of the number of imide rings to the total number of amic acid structures and imide rings in the imidized polymer as a percentage. At this time, a part of the imide ring may be an isoimide ring. The imidation rate of the imidized polymer is determined from ¹ H-NMR obtained by dissolving the imidized polymer in an appropriate deuterated solvent (for example, deuterated dimethyl sulfoxide) and measuring tetramethylsilane as a reference material at room temperature. Formula (i) below

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

(In Formula (i), A ¹ is a peak area derived from protons of NH groups appearing in the vicinity of 10 ppm, A ² is a peak area derived from other protons, and α is a precursor of an imidized polymer (polyamic acid). The number ratio of other protons to one proton of NH group in)
Can be obtained.

[End-modified polymer]
The polyamic acid and the imidized polymer thereof may be of a terminal modified type with a controlled molecular weight. Such a terminal-modified type 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, and n-undecyl. Amine, n-dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecylamine, n-octadecylamine, n-eicosylamine, etc. be able to. Examples of the monoisocyanate compound include phenyl isocyanate and naphthyl isocyanate.
The use ratio of these molecular weight regulators is preferably 20% by weight or less, more preferably 10% by weight or less, based on the total of tetracarboxylic dianhydride and diamine used when synthesizing the polyamic acid. is there.
[Solution viscosity]
The polyamic acid and the imidized polymer thereof preferably have a solution viscosity of 20 to 800 mPa · s, and have a solution viscosity of 30 to 500 mPa · s, respectively, when a 10% by weight solution is obtained. More preferably.
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, N-methyl-2-pyrrolidone, γ-butyrolactone, etc.). It is a value measured at 25 ° C. using a mold rotational viscometer.

(B) Epoxy compound having two or more perfluoroalkyl groups (b) The epoxy compound having two or more perfluoroalkyl groups contained in the liquid crystal aligning agent of the present invention is preferably represented by the following formula (B).

(In the formula (B), R is a divalent organic group having two or more perfluoroalkyl groups.)
It is a compound represented by these. R in the formula (B) is preferably a divalent organic group having one or more alicyclic rings or aromatic rings. The alicyclic ring is preferably an alicyclic ring having 4 to 18 carbon atoms, and examples thereof include a cyclopentane ring, a cyclohexane ring, and a cycloheptane ring. The aromatic ring is preferably an aromatic ring having 6 to 18 carbon atoms, and examples thereof include a benzene ring, a biphenyl ring, a naphthalene ring, an anthracene ring, and a triphenylene ring. The total number of carbon atoms in divalent R is preferably 6 to 72, more preferably 6 to 36, and the number of perfluoroalkyl groups contained in one molecule is preferably 2 to 36. More preferably, it is 2 to 12, and particularly preferably 2 to 4. Note that (b) the epoxy compound having two or more perfluoroalkyl groups may have a fluorine atom at a site other than the perfluoroalkyl group.
(B) Especially as an epoxy compound which has a 2 or more perfluoroalkyl group, following formula (B-1), (B-2) or (B-3)

(In the above formula, a is each independently an integer of 1 to 8, b is an integer of 1 to 4, c is 2 or 3, and d is each independently an integer of 0 to 4) E is independently an integer of 0 to 3, f is independently an integer of 1 to 4, and g is independently an integer of 1 to 3.)
It is preferable that it is a compound represented by these. In the above formulas (B-1), (B-2) and (B-3), a is preferably 1, that is, (b) an epoxy compound having 2 or more perfluoroalkyl groups is 2 or more tri An epoxy compound having a fluoromethyl group is preferred. In the above formula (B-1), b is preferably 1, and c is preferably 2. In the above formula (B-2), d is preferably 0 or 1, and e is preferably 0 or 1. In the above formula (B-3), f is preferably 1, and g is preferably 1.
Specific examples of the compound represented by the above formula (B-1) include, for example, N, N, N ′, N′-tetraglycidyl-4,4′-diamino-2,2′-bis (trifluoromethyl). Biphenyl and the like;
Specific examples of the compound represented by the formula (B-2) include, for example, N, N, N ′, N′-tetraglycidyl-2,2′-bis (4-aminophenyl) hexafluoropropane, N, N, N ′, N′-tetraglycidyl-2,2′-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, N, N, N ′, N′-tetraglycidyl-2,2′- Bis [4- (4-amino-2-trifluoromethylphenoxy) phenyl] hexafluoropropane and the like;
Specific examples of the compound represented by the formula (B-3) include N, N, N ′, N′-tetraglycidyl-4,4′-bis [(4-amino-2-trifluoromethyl), for example. Phenoxy] -octafluorobiphenyl and the like can be mentioned as preferable examples.
In the liquid crystal aligning agent of the present invention, (b) the content ratio of the epoxy compound having two or more perfluoroalkyl groups is 0.01 to 40 parts by weight with respect to 100 parts by weight of the polymer (a). The amount is preferably 0.05 to 40 parts by weight, more preferably 1 to 30 parts by weight. When (b) a part of an epoxy compound having two or more perfluoroalkyl groups is used by being replaced with another epoxy compound described below, the above content ratio is (b) two or more perfluoroalkyl groups. It should be understood as the sum of the content ratio of the epoxy compound having a fluoroalkyl group and the content ratio of other epoxy compounds.
In the liquid crystal aligning agent of the present invention, a part of the epoxy compound having (b) two or more perfluoroalkyl groups is replaced with another epoxy compound as long as the effects and advantages of the present invention are not impaired. May be. Examples of such other epoxy compounds include, for example, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1 , 6-hexanediol 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 Examples include '-diaminodiphenylmethane, N, N, -diglycidyl-benzylamine, N, N-diglycidyl-aminomethylcyclohexane, and the like.
In the liquid crystal aligning agent of the present invention, when (b) a part of the epoxy compound having two or more perfluoroalkyl groups is used by replacing with another epoxy compound, the use ratio of the other epoxy compound is (b) Preferably it is 20 weight% or less with respect to the sum total of the epoxy compound which has a 2 or more perfluoroalkyl group, and another epoxy compound, More preferably, it is 10 weight% or less, Furthermore, it is 5 weight% or less. preferable. In the liquid crystal aligning agent of this invention, it is most preferable not to use another epoxy compound.

<Other ingredients>
The liquid crystal aligning agent of the present invention contains the above (a) polymer and (b) an epoxy compound having two or more perfluoroalkyl groups as essential components, but can optionally contain other components. . Examples of such other additives include functional silane compounds.
The functional silane compound can be added to improve the adhesion of the liquid crystal alignment film to be formed to the substrate surface. Examples of such functional silane compounds 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, , 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 (Oxyethylene) -3-aminopropyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane and the like can be mentioned. The use ratio of these functional silane compounds is preferably 2 parts by weight or less, more preferably 0.2 parts by weight or less with respect to 100 parts by weight of the polymer (a).

<Liquid crystal aligning agent>
In the liquid crystal aligning agent of the present invention, the (a) polymer and (b) an epoxy compound having two or more perfluoroalkyl groups and other optional components are preferably dissolved in an organic solvent. Prepared as a contained solution state.
As an organic solvent which can be used for the liquid crystal aligning agent of this invention, the solvent illustrated as what is used for the synthesis reaction of a specific polyamic acid can be mentioned. Moreover, the poor solvent illustrated as what can be used together in the case of the synthesis reaction of specific 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.

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 of the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) can be appropriately set in consideration of viscosity, volatility, and the like. However, it is preferably in the range of 1 to 10% by 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, but the solid content concentration is less than 1% by weight. The film thickness of this coating film is too small to obtain a good liquid crystal alignment film, and when the solid content concentration exceeds 10% by weight, the film thickness of the coating film is too large to be equally good liquid crystal. It is difficult to obtain an alignment film, and the viscosity of the liquid crystal aligning agent increases, resulting in poor coating properties.
The particularly preferable solid content concentration range varies depending on the method used when the liquid crystal aligning agent is applied to the substrate. For example, when the spinner method is used, the range of 1.5 to 4.5% by weight is particularly preferable. In the case of the 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 is in the range of 12 to 50 mPa · s. In the case of the inkjet 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 is in the range of 3 to 15 mPa · s.
The temperature at which the liquid crystal aligning agent of the present invention is prepared is preferably 0 ° C to 200 ° C, more preferably 20 ° C to 60 ° C.

<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.
First, the liquid crystal aligning agent of the present invention is applied to the transparent conductive film side of the substrate provided with the patterned transparent conductive film by an appropriate application method such as a roll coater method, a spinner method, a printing method, or an ink jet method. For example, the coating film is formed by heating at a temperature of 40 to 250 ° C. for 0.1 to 120 minutes. The thickness of the coating film is preferably 0.001 to 1 μm, more preferably 0.005 to 0.5 μm, as the thickness after removal of the solvent.
Examples of the substrate include glass such as float glass and soda glass, and a transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, and poly (alicyclic olefin).
As the transparent conductive film, a NESA film made of SnO _{2 or} an ITO film made of In ₂ O ₃ —SnO ₂ can be used. In order to form 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 A method of directly forming a patterned transparent conductive film using the method is used.
When applying the liquid crystal aligning agent, in order to further improve the adhesion between the substrate and the transparent conductive film and the coating film, a functional silane compound, titanate or the like is previously applied on the substrate and the transparent conductive film. Also good.

When the liquid crystal alignment film formed from the liquid crystal aligning agent of the present invention is used for a horizontal alignment type liquid crystal display element, a cloth made of fibers such as nylon, rayon, and cotton is then applied to the formed coating film surface. A rubbing process is performed by rubbing in a certain direction with a wound roll. By this rubbing treatment, the coating film is provided with an alignment ability of liquid crystal molecules to form a liquid crystal alignment film. Further, for example, Patent Document 6 (JP-A-6-222366) and Patent Document 7 (JP-A-6-281937) show liquid crystal alignment films formed with the liquid crystal aligning agent of the present invention. A process for changing the pretilt angle by irradiating a part of the liquid crystal alignment film with ultraviolet light, or a resist on a part of the surface of the liquid crystal alignment film as disclosed in Patent Document 8 (Japanese Patent Laid-Open No. 5-107544) It can be obtained by forming a film and performing a rubbing process in a direction different from the previous rubbing process, and then removing the resist film, so that the liquid crystal alignment film has a different liquid crystal alignment ability for each region. It is possible to improve the visual field characteristics of the horizontal liquid crystal display element.
On the other hand, when the liquid crystal alignment film is applied to a vertical alignment type liquid crystal display element, this rubbing treatment may not be performed.
A liquid crystal cell is manufactured by preparing two substrates on which a liquid crystal alignment film is formed as described above, and disposing a liquid crystal between the two substrates. In order to manufacture a liquid crystal cell, the following two methods are mentioned, for example.
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 step, 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. The liquid crystal aligning agent of this invention has the advantage which can give the liquid crystal aligning film by which the liquid crystal dripping nonuniformity and the liquid crystal fusion part nonuniformity were reduced when it used for ODF method.
In any case, it is desirable to remove the flow alignment at the time of injection by heating the liquid crystal cell to a temperature at which the liquid crystal used has an isotropic phase and then slowly 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.

As the sealing agent, for example, an aluminum oxide sphere as a spacer and an epoxy resin containing a curing agent can be used.
As the liquid crystal, for example, a nematic liquid crystal, a smectic liquid crystal, or the like can be used. When manufacturing a liquid crystal display element having a TN liquid crystal cell or an STN liquid crystal cell, a nematic liquid crystal having positive dielectric anisotropy (positive liquid crystal) is preferable, for example, a biphenyl liquid crystal or a phenylcyclohexane system. Liquid crystal, ester liquid crystal, terphenyl liquid crystal, biphenylcyclohexane liquid crystal, pyrimidine liquid crystal, dioxane liquid crystal, bicyclooctane liquid crystal, cubane liquid crystal and the like are used. For example, 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 (Merck); p-decyloxybenzylidene- A ferroelectric liquid crystal such as p-amino-2-methylbutyl cinnamate may be further added and used.
On the other hand, in the case of a vertical alignment type liquid crystal cell, a nematic type liquid crystal having negative dielectric anisotropy (negative type liquid crystal) is preferable. For example, dicyanobenzene liquid crystal, pyridazine liquid crystal, Schiff base liquid crystal, azoxy liquid crystal Type liquid crystal, biphenyl type liquid crystal, phenylcyclohexane type liquid crystal and the like are used.
The polarizing plate used outside the liquid crystal cell is composed of a polarizing film called “H film” in which polyvinyl alcohol is stretched and oriented while absorbing iodine and sandwiched between cellulose acetate protective films, or the H film itself. A polarizing plate etc. can be mentioned.
The liquid crystal display element of the present invention thus produced does not have a display defect due to liquid crystal alignment unevenness and exhibits excellent display quality.

In the following synthesis examples, the solution viscosity of the polymer solution is a value measured by E at 25 ° C. using a perennial clock.
Imidization ratio of imidization polymer was thoroughly dried under reduced pressure imidized polymer at room temperature, dissolved in deuterated dimethyl sulfoxide, from the equation ^{1 H-NMR} was measured using tetramethylsilane as a standard substance ( determined by i).
<Synthesis of polyamic acid>
Synthesis example 1
110 g (0.50 mol) of pyromellitic dianhydride as tetracarboxylic dianhydride and 98 g (0.50 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 4,4- as diamine 200 g (1.0 mol) of diaminodiphenyl ether was dissolved in a mixed solvent consisting of 230 g of N-methyl-2-pyrrolidone and 2,010 g of γ-butyrolactone, reacted at 40 ° C. for 3 hours, and then 1,350 g of γ-butyrolactone was added. By addition, about 3,800 g of a solution containing 10% by weight of polyamic acid (A-1) was obtained. The solution viscosity of this polyamic acid solution was 200 mPa · s.
Synthesis example 2
1,2,3,4-Cyclobutanetetracarboxylic dianhydride 98 g (0.50 mol) and pyromellitic dianhydride 110 g (0.50 mol) as tetracarboxylic dianhydride and 4,4 ′ as diamine -200 g (1.0 mol) of diaminodiphenylmethane was dissolved in a mixed solvent consisting of 230 g of N-methyl-2-pyrrolidone and 2,100 g of γ-butyrolactone, reacted at 40 ° C. for 3 hours, and then 1,350 g of γ-butyrolactone. As a result, about 3,800 g of a solution containing 10% by weight of polyamic acid (A-2) was obtained. The solution viscosity of this polyamic acid solution was 125 mPa · s.

Synthesis example 3
200 g (1.0 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride as tetracarboxylic dianhydride and 200 g (1.0 mol) of 4,4′-diaminodiphenyl ether as diamine were added to N-methyl. After dissolving in a mixed solvent consisting of 230 g of 2-pyrrolidone and 2,050 g of γ-butyrolactone and reacting at 40 ° C. for 4 hours, 1,300 g of γ-butyrolactone was added to obtain polyamic acid (A-3). About 3,800 g of a solution containing 10% by weight was obtained. The solution viscosity of this polyamic acid solution was 210 mPa · s.
Synthesis example 4
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 370 g of N-methyl-2-pyrrolidone and 3,300 g of γ-butyrolactone and reacted at 40 ° C. for 3 hours to contain 10% by weight of polyamic acid (A-4). About 3,700 g of solution was obtained. The solution viscosity of this polyamic acid solution was 160 mPa · s.
Synthesis example 5
2,3,5-Tricarboxycyclopentyl acetic acid dianhydride 220 g (1.0 mol) as tetracarboxylic dianhydride and 200 g (1.0 mol) of 4,4′-diaminodiphenyl ether as diamine were added to N-methyl-2 -It was dissolved in a mixed solvent consisting of 240 g of pyrrolidone and 3,500 g of γ-butyrolactone, and reacted at 40 ° C for 4 hours to obtain about 4,000 g of a solution containing 10% by weight of polyamic acid (A-5). The solution viscosity of this polyamic acid solution was 38 mPa · s.

<Synthesis of imidized polymer>
Synthesis Example 6
110 g (0.50 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride and 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro -2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione 160 g (0.50 mol), p-phenylenediamine 95 g (0.88 mol) as diamine, 32 g (0.10 mol) of 2,2-ditrifluoromethyl-4,4-diaminobiphenyl and 6.4 g (0.010 mol) of 3,6-bis (4-aminobenzoyloxy) cholestane and octadecylamine 8 as monoamine 0.1 g (0.03 mol) was dissolved in 960 g of N-methyl-2-pyrrolidone (NMP) and reacted at 60 ° C. for 9 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 58 mPa · s.
To the obtained polyamic acid solution, 2,730 g of NMP, 400 g of pyridine and 410 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 2,300 g of a solution containing 15% by weight of an imidized polymer (B-1) having a rate of about 95% was obtained. 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 69 mPa · s.
Synthesis example 7
110 g (0.50 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride and 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro -2,5-dioxo-3-furanyl) naphtho [1,2-c] furan-1,3-dione 160 g (0.50 mol), p-phenylenediamine 94 g (0.87 mol) as diamine, 1, 25 g (0.10 mol) of 3-bis (3-aminopropyl) tetramethyldisiloxane and 9.6 g (0.015 mol) of 3,6-bis (4-aminobenzoyloxy) cholestane and octadecylamine as monoamine. 1 g (0.030 mol) was dissolved in 960 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 60 mPa · s.
Next, 2,700 g of NMP was added to the obtained polyamic acid solution, 400 g of pyridine and 410 g of acetic anhydride were added, and dehydration ring closure 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 2,400 g of a solution containing 15% by weight of imidized polymer (B-2) having an imidization ratio of about 95%. Obtained. 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 70 mPa · s.

Synthesis Example 8
220 g (1.0 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride and 110 g (0.99 mol) of p-phenylenediamine and 3,6-bis (4- 6.4 g (0.010 mol) of aminobenzoyloxy) cholestane is dissolved in 3,040 g of N-methyl-2-pyrrolidone and reacted at 60 ° C. for 6 hours to obtain a polyamic acid solution having a solution viscosity of about 260 mPa · s. It was.
Next, 2,700 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 400 g of pyridine and 310 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 2,700 g of a solution containing 15% by weight of an imidized polymer (B-3) having an imidization ratio of about 89%. Obtained. 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 300 mPa · s.
Synthesis Example 9
110 g (0.50 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride and 1,3,3a, 4,5,9b-hexahydro-8-methyl-5 (tetrahydro- 2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione 160 g (0.50 mol) and p-phenylenediamine 90 g (0.83 mol) as diamine, 2 , 2′-ditrifluoromethyl-4,4′-diaminobiphenyl 32 g (0.10 mol), 1- (3,5-diaminobenzoyloxy) -4- (4-trifluoromethylbenzoyloxy) -cyclohexane 25 g ( 0.059 mol) and 4.0 g (0.011 mol) of octadecanoxy-2,5-diaminobenzene were added to N-methyl-2-pyrrolidone. Was dissolved in NMP) 2,200g, it was reacted for 6 hours at 60 ° C.. 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 110 mPa · s.
3,800 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 800 g of pyridine and 500 g of acetic anhydride were added, and dehydration ring closure 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 2,300 g of a solution containing 15% by weight of imidized polymer (B-4) having an imidization ratio of about 92%. Obtained. A small amount of this solution was collected, 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 Example 10
110 g (0.50 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as tetracarboxylic dianhydride, 38 g (0.35 mol) of p-phenylenediamine as diamine, 20 g of 4,4′-diaminodiphenylmethane (0.1 mol) and 26 g (0.05 mol) of 3 (3,5-diaminobenzoyloxy) cholestane were dissolved in 800 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 60 mPa · s.
1,800 g of NMP was added to the obtained polyamic acid solution, 80 g of pyridine and 100 g of acetic anhydride were added, and dehydration ring closure was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with new γ-butyrolactone to obtain about 1,100 g of a solution containing 15% by weight of an imidized polymer (C-1) having an imidization ratio of about 80%. Obtained. 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 87 mPa · s.
Synthesis Example 11
110 g (0.50 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride and 49 g (0.45 mol) and 3 (3,5-diaminobenzoyl) of p-phenylenediamine as diamine 26 g (0.05 mol) of oxy) cholestane was dissolved in 750 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 58 mPa · s.
1,800 g of NMP was added to the obtained polyamic acid solution, 40 g of pyridine and 51 g of acetic anhydride were added, and dehydration ring closure was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with new γ-butyrolactone to obtain about 1,100 g of a solution containing 15% by weight of an imidized polymer (C-2) having an imidization ratio of about 50%. Obtained. 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 85 mPa · s.

Synthesis Example 12
110 g (0.50 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as tetracarboxylic dianhydride, 38 g (0.35 mol) of p-phenylenediamine as diamine, 20 g of 4,4′-diaminodiphenylmethane (0.1 mol) and 26 g (0.05 mol) of 3 (3,5-diaminobenzoyloxy) cholestane were dissolved in 800 g of N-methyl-2-pyrrolidone (NMP) and reacted at 60 ° C. for 6 hours. It was. 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 60 mPa · s.
1,800 g of NMP was added to the obtained polyamic acid solution, 80 g of pyridine and 100 g of acetic anhydride were added, and dehydration ring closure was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with new γ-butyrolactone to obtain about 1,100 g of a solution containing 15% by weight of an imidized polymer (C-3) having an imidization ratio of about 80%. Obtained. 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 87 mPa · s.

<Preparation and evaluation of liquid crystal aligning agent>
Example 1
[Preparation of liquid crystal aligning agent]
The solution containing the polyamic acid (A-1) obtained in Synthesis Example 1 and the solution containing the imidized polymer (B-1) obtained in Synthesis Example 6 are used as the polyamic contained in these solutions. The acid (A-1): imidized polymer (B-1) was mixed so that the weight ratio was 50:50 (weight ratio), where γ-butyrolactone (BL), N-methyl-2-pyrrolidone was mixed. (NMP) and butyl cellosolve (BC) are added, and N, N, N ′, N′-tetraglycidyl-4,4′-diamino-2,2′-bis (trifluoromethyl) is added as an epoxy compound having a fluorine atom. 10 parts by weight of biphenyl is added to 100 parts by weight of the total of polyamic acid and imidized polymer, the solid content concentration is 4% by weight, and the solvent composition is BL: NMP: BC = 68: 20: 12 (weight ratio). is there It was a liquid. A liquid crystal aligning agent was prepared by filtering this solution using a filter having a pore diameter of 1 μm.
[Evaluation of liquid crystal wettability]
The liquid crystal aligning agent prepared above is applied to the transparent electrode surface of the glass substrate with transparent electrode (ITO substrate) made of an ITO film using a spinner, heated on an 80 ° C. hot plate for 1 minute, and then heated to 200 ° C. By heating for 10 minutes on a hot plate and removing the solvent, a coating film having an average film thickness of 80 mm was formed on the ITO substrate. On this coating film, 8 μL of a positive nematic liquid crystal (MLC-6221, manufactured by Merck & Co., Inc.) was dropped using a syringe with a needle tip of 0.5 mm, and the contact angle between the coating film and the liquid crystal when 50 seconds passed after the dropping. Was measured, and the contact angle was 10 °.
The present inventors found that liquid crystal dropping unevenness and liquid crystal fusion portion unevenness when the liquid crystal dropping method (ODF) is applied is caused by insufficient affinity (liquid crystal wettability) between the liquid crystal alignment film and the liquid crystal. I found out. When the contact angle is 15 ° or less, the liquid crystal wettability is good, and it has been empirically revealed that liquid crystal dripping unevenness and liquid crystal fusion portion unevenness do not occur in such a case.

[Manufacture of liquid crystal cells]
The liquid crystal aligning agent prepared above is applied to a transparent electrode surface of a glass substrate with transparent electrodes (ITO substrate) made of an ITO film using a liquid crystal alignment film printer (Nissha Printing Co., Ltd.) and 80 ° C. The film was heated on a hot plate for 1 minute and then heated on a hot plate at 200 ° C. for 10 minutes to remove the solvent, thereby forming a coating film having an average film thickness of 600 mm on the ITO substrate. This coating film is rubbed with a rubbing machine having a roll wrapped with rayon cloth at a roll rotation speed of 500 rpm, a stage moving speed of 3 cm / sec, and a hair foot indentation length of 0.4 mm, and the coating film is aligned with liquid crystal. Added the ability. Furthermore, the liquid crystal alignment film was formed on the ITO board | substrate by ultrasonically cleaning for 1 minute in ultrapure water, and drying for 10 minutes in a 100 degreeC clean oven. This operation was repeated to produce a pair (two) of ITO substrates having a liquid crystal alignment film on the transparent electrode surface.
After applying an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm to the respective outer edges of the pair of ITO substrates having the liquid crystal alignment film, the liquid crystal alignment film surfaces are stacked and pressure-bonded so as to face each other. The agent was cured. Next, after filling nematic liquid crystal (MLC-6221, manufactured by Merck & Co., Inc.) into the gap between the liquid crystal injection port and the substrate, the liquid crystal injection port was sealed with an acrylic photo-curing adhesive to produce a liquid crystal cell.
[Evaluation of liquid crystal alignment]
For the liquid crystal cell manufactured above, the display surface when the voltage is OFF and when AC 5 V is applied is visually observed. If the abnormal domain is not observed, the liquid crystal orientation is “good”, and the abnormal domain is recognized. When the liquid crystal orientation was evaluated as “bad”, the liquid crystal orientation of the liquid crystal cell was “good”.
[Voltage holding ratio]
When a voltage of 5 V was applied to the liquid crystal cell produced above at 60 ° C. with an application time of 60 microseconds and a span of 167 milliseconds, and the voltage holding ratio after 167 milliseconds after the application release was measured, The voltage holding ratio of the cell was 99.1%. If this value is 95% or more, it can be said that the voltage holding ratio is good.
The measurement of the voltage holding ratio was performed using a model “VHR-1” manufactured by Toyo Corporation.
[Measurement of residual DC voltage]
A direct current DC voltage of 17.0 V was applied to the liquid crystal cell manufactured above at an environmental temperature of 100 ° C. for 20 hours, and after the direct current voltage was cut off, the liquid crystal cell was allowed to cool at room temperature for 15 minutes and then remained in the liquid crystal cell (residual DC voltage) was determined by the flicker erasing method, and the residual DC voltage of the liquid crystal cell was 280 mV. When this value is 800 mV or less, it can be said that the residual DC voltage is good.

Examples 2 to 15 and Comparative Examples 1 to 3
In the above Example 1, the same manner as in Example 1 except that the types and amounts of the polymer and epoxy compound contained in the polymer solution used and the solvent composition of the solution were as shown in Table 1. An alignment agent was prepared and evaluated. The evaluation results are shown in Table 1.

In Table 1 above, the abbreviations for epoxy compounds and solvents have the following meanings, respectively.
Epoxy compound E-1: N, N, N ′, N′-tetraglycidyl-4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl E-2: N, N, N ′, N '-Tetraglycidyl-2,2'-bis (4-aminophenyl) hexafluoropropane E-3: N, N, N', N'-tetraglycidyl-2,2'-bis [4- (4-amino Phenoxy) phenyl] hexafluoropropane E-4: N, N, N ′, N′-tetraglycidyl-2,2′-bis [4- (4-amino-2-trifluoromethylphenoxy) phenyl] hexafluoropropane E-5: N, N, N ′, N′-tetraglycidyl-4,4′-bis [(4-amino-2-trifluoromethyl) phenoxy] -octafluorobiphenyl E-6: polyethylene glycol glycidyl ether E -7: 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane solvent BL: γ-butyrolactone NMP: N-methyl-2-pyrrolidone BC: Butyl cellosolve

Example 16
[Preparation of liquid crystal aligning agent]
The solution containing the imidized polymer (C-1) obtained in Synthesis Example 10 was taken in an amount corresponding to 100 parts by weight in terms of the imidized polymer (C-1) contained therein. Here, 10 parts by weight of N, N, N ′, N ′,-tetraglycidyl-4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl was added as an epoxy compound having a fluorine atom. Further, N-methyl-2-pyrrolidone and butyl cellosolve were added to obtain a solution having a solid content concentration of 2.5% by weight and a solvent composition of NMP: BC = 50: 50 (weight ratio). A liquid crystal aligning agent was prepared by filtering this solution using a filter having a pore diameter of 1 μm.
[Evaluation of liquid crystal wettability]
With respect to the liquid crystal aligning agent prepared above, a coating film was formed in the same manner as in Example 1, and the liquid crystal wettability was evaluated. As a result, the contact angle between the coating film and the liquid crystal was 13 °.
[Manufacture of liquid crystal cells]
The liquid crystal aligning agent prepared above is applied to a transparent electrode surface of a glass substrate with transparent electrodes (ITO substrate) made of an ITO film using a liquid crystal alignment film printer (Nissha Printing Co., Ltd.) and 80 ° C. On the hot plate for 1 minute, and then on the hot plate at 200 ° C. for 10 minutes to remove the solvent, thereby forming a coating film (liquid crystal alignment film) with an average thickness of 1,000 mm on the ITO substrate. did. This operation was repeated to produce a pair (two) of ITO substrates having a liquid crystal alignment film on the transparent electrode surface.
After applying an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm to the respective outer edges of the pair of ITO substrates having the liquid crystal alignment film, the liquid crystal alignment film surfaces are stacked and pressure-bonded so as to face each other. The agent was cured. Next, a negative type nematic liquid crystal (MLC-6608, manufactured by Merck & Co., Inc.) is filled into the gap between the liquid crystal inlet and the substrate, and then the liquid crystal inlet is sealed with an acrylic photo-curing adhesive to produce a liquid crystal cell. did.
[Evaluation of liquid crystal alignment]
The liquid crystal cell produced above was evaluated for liquid crystal orientation in the same manner as in Example 1. As a result, the liquid crystal orientation of the liquid crystal cell was “good”.
[Measurement of voltage holding ratio and residual DC voltage]
The liquid crystal cell manufactured above was measured for the voltage holding ratio and the residual DC voltage in the same manner as in Example 1. As a result, the voltage holding ratio was 99.5% and the residual DC voltage was 550 mV. Also good results.

Examples 17-40, Comparative Examples 4-9
In Example 16, a liquid crystal aligning agent was prepared and evaluated in the same manner as in Example 16 except that the type of polymer and the type and amount of epoxy compound were as shown in Table 2. The evaluation results are shown in Table 2.

  The abbreviations of the epoxy compounds in Table 2 are the same as those in Table 1.

Claims (7)

(A) at least one polymer selected from the group consisting of polyamic acid and imidized polymer thereof, and (b) a compound having 3 or more epoxy groups and 2 or more perfluoroalkyl groups in the molecule. Liquid crystal aligning agent characterized by containing. The component (b) is represented by the following formula (B)

(In the formula (B), R is a divalent organic group having two or more perfluoroalkyl groups.)
The liquid crystal aligning agent of Claim 1 which is a compound represented by these.   The liquid crystal aligning agent of Claim 2 in which the group R in the formula (B) has one or more alicyclic rings or aromatic rings. The component (b) is represented by the following formula (B-1), (B-2) or (B-3)

(In the above formula, a is each independently an integer of 1 to 8, b is an integer of 1 to 4, c is 2 or 3, and d is each independently an integer of 0 to 4) E is independently an integer of 0 to 3, f is independently an integer of 1 to 4, and g is independently an integer of 1 to 3.)
The liquid crystal aligning agent of Claim 3 which is a compound represented by these.   The liquid crystal aligning agent as described in any one of Claims 1-4 which contains 0.01-40 weight part of components (b) with respect to 100 weight part of components (a).   The component (a) is selected from the group consisting of a polyamic acid obtained by reacting a tetracarboxylic dianhydride containing 2,3,5-tricarboxycyclopentylacetic acid dianhydride and a diamine, and an imidized polymer thereof. The liquid crystal aligning agent as described in any one of Claims 1-5 which is at least 1 type of polymer.   A liquid crystal display device comprising a liquid crystal alignment film formed from the liquid crystal alignment agent according to claim 1.