JP5585755B2 - 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, the present invention relates to a liquid crystal aligning agent that provides a liquid crystal aligning film exhibiting excellent heat resistance, and a liquid crystal display element that does not deteriorate display quality even when driven for a long time.

At present, as a liquid crystal display element, a liquid crystal alignment film is formed on the surface of a substrate provided with a transparent conductive film to form a liquid crystal display element substrate. A so-called TN type (twisted nematic) in which a layer of a nematic liquid crystal having a liquid crystal layer is formed into a sandwich cell and the major axis of liquid crystal molecules is continuously twisted by 90 ° from one substrate to the other substrate. TN type liquid crystal display elements having a liquid crystal cell are widely 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 with less viewing angle dependency, and an IPS type electrode structure FFS (Fringe Field Switching) type liquid crystal display element with improved brightness by increasing the aperture ratio of the display element part, OCB (Optical Compensated Bend: optical with low viewing angle dependency and excellent high-speed response of the video screen Compensation bend) type liquid crystal display elements, and VA (vertical alignment) type liquid crystal display elements using nematic liquid crystal having negative dielectric anisotropy have been developed.
As materials for the liquid crystal alignment film in these liquid crystal display elements, resin materials such as polyamic acid, polyimide, polyamide, and polyester are known. In particular, a liquid crystal alignment film made of polyamic acid or polyimide has heat resistance and mechanical strength. It has excellent affinity with liquid crystal and the like, and is used in many liquid crystal display elements (see, for example, Patent Documents 1 to 3).

The liquid crystal display element as described above is required to be driven for a longer time than in the past. For example, as typified by recent liquid crystal televisions, it is required to maintain a good display state for a long time (for example, 10 years or more). There is a demand for characteristics that maintain the retention rate (hereinafter also referred to as “heat resistance”).
Conventionally known resin materials for liquid crystal alignment films have been improved in heat resistance by using polyimide rather than polyamic acid and by using p-phenylenediamine as a monomer for producing the same. However, there is a limit to the improvement in heat resistance by such measures, and depending on the conventionally known resin materials for liquid crystal alignment films, satisfying the heat resistance in the increasingly severe use environment of liquid crystal display elements is not possible. It is becoming impossible.

JP-A-9-197411 JP 2003-149648 A JP 2003-107486 A JP-A-6-222366 JP-A-6-281937 JP-A-5-107544

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a liquid crystal alignment film having a high degree of heat resistance in which a voltage holding ratio does not decrease even when a thermal stress is applied for a long time. It is an object of the present invention to provide a liquid crystal aligning agent that can be used and a liquid crystal display element that does not deteriorate display quality even when driven for a long time.
Still other objects and advantages of the present invention will become apparent from the following description.

In accordance with the present invention, the above objects and advantages of the present invention are primarily as follows:
At least one polymer selected from the group consisting of polyamic acid and polyimide, provided that at least a part of the polymer has the following formula (A):

It is achieved by the liquid crystal aligning agent containing which has the structure represented by these.
The above objects and advantages of the present invention are, secondly,
This is achieved by a liquid crystal display element comprising a liquid crystal alignment film formed from the above liquid crystal aligning agent.

The liquid crystal aligning agent of the present invention can provide a liquid crystal aligning film in which the voltage holding ratio does not decrease even when heat stress is applied for a long time.
The liquid crystal display element of the present invention having the liquid crystal alignment film formed from the liquid crystal aligning agent of the present invention does not deteriorate the display quality even when driven for a long time. Accordingly, the liquid crystal display element of the present invention can be effectively applied to various devices, such as watches, portable games, word processors, notebook computers, car navigation systems, camcorders, PDAs (Personal Digital Assistants), digital cameras, It can be suitably used for display devices such as mobile phones, various monitors, and liquid crystal televisions.

Hereinafter, the present invention will be described in detail.
The liquid crystal aligning agent of the present invention is at least one polymer selected from the group consisting of polyamic acid and polyimide, provided that the polymer has a structure represented by the above formula (A) in at least a part of the molecule. , Containing. Hereinafter, such a polymer is referred to as a “specific polymer” in the present specification. In the specific polymer, the structure represented by the formula (A) may be present in the main chain of the polymer, may be present in the side chain of the polymer, or may be present in the polymer. It may be present in both the main chain and the side chain.
Examples of the structure represented by the above formula (A) include the following formulas (A-1) to (A-3).

(R ^a in the formula (A-1) is a halogen atom, a cyano group, an isocyano group, —OCN, —NCO, —SCN, —NCS or an azide group, n is an integer of 0 to 3, and “* "Indicates that each is a bond;
R ^b and R ^c in formulas (A-2) and (A-3) are each independently a hydrogen atom, a halogen atom, a cyano group, an isocyano group, —OCN, —NCO, —SCN, —NCS or And “*” indicates a bond. )
It is preferable that it is at least 1 type of structure selected from the group which consists of a structure represented by each.
The content ratio of the structure represented by the above formula (A) in the polymer is preferably 2.0 × 10 ⁻⁵ mol / g or more, and 1.0 × 10 ^{−4 to} 3.0 × 10. It is more preferably ⁻³ mol / g, particularly preferably 2.0 × 10 ^{−4 to} 1.0 × 10 ⁻³ mol / g.
Polyamic acid having a structure represented by the above formula (A) in at least a part of the molecule,
And Te tetracarboxylic acid dianhydride, and a diamine containing a compound having a structure and two amino groups represented by the above formula (A), can be obtained by reacting,
Polyimide having a structure represented by the above formula (A) in at least a part of the molecule can be obtained by dehydrating cyclization of the polyamic acid obtained as described above follow.

<Tetracarboxylic dianhydride>
Examples of tetracarboxylic dianhydrides used for synthesizing preferred polyamic acids in the liquid crystal aligning agent of the present invention include alicyclic tetracarboxylic dianhydrides, aliphatic tetracarboxylic dianhydrides, and aromatic tetracarboxylic acids. Mention may be made of dianhydrides.
Specific examples of the alicyclic tetracarboxylic dianhydride include, for example, 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic. Acid 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, cis-3,7-dibutylcycloocta-1,5-diene-1,2,5,6 -Tetracarboxylic Dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride 3,5,6-tricarbonyl-2-carboxynorbornane-2: 3,5: 6-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 [ , 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, 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), the following formulas (TI) and (T-II)

(In the formulas (T-I) and (T-II), R ¹ and R ³ are each a divalent organic group having an aromatic ring, and R ² and R ⁴ are each a hydrogen atom or an alkyl group. And a plurality of R ² and R ⁴ may be the same or different.)
The compound etc. which are represented by each of these can be mentioned.
Specific examples of the aliphatic tetracarboxylic dianhydride include butanetetracarboxylic dianhydride.
Specific examples of the aromatic tetracarboxylic dianhydride include, for example, 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'-dimethyldiphenylsilane tetracarboxylic dianhydride, 3,3 ', 4,4'-tetraphenylsilane tetracarboxylic dianhydride 1,2,3,4-furantetracarboxylic dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 4,4′-bis (3,4-di Carboxyphenoxy Diphenylsulfone dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenylpropane dianhydride, 3,3 ′, 4,4′-perfluoroisopropylidenediphthalic dianhydride, 3, 3 ′, 4,4′-biphenyltetracarboxylic dianhydride, bis (phthalic acid) phenylphosphine oxide dianhydride, p-phenylene-bis (triphenylphthalic acid) dianhydride, m-phenylene-bis (tri Phenylphthalic acid) dianhydride, bis (triphenylphthalic acid) -4,4'-diphenyl ether dianhydride, bis (triphenylphthalic acid) -4,4'-diphenylmethane dianhydride, ethylene glycol-bis (an Hydrotrimellitate), propylene glycol-bis (anhydrotrimellitate), 1,4-butanediol-bis (anhydro) Remellitate), 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)

The compound etc. which are represented by each of these can be mentioned.
These tetracarboxylic dianhydrides can be used singly or in combination of two or more.
The tetracarboxylic dianhydride used for synthesizing a preferred polyamic acid in the liquid crystal aligning agent of the present invention includes alicyclic tetracarboxylic dianhydride and pyromellitic dianhydride and 2,2 ′, 3,3. It is preferable to include at least one selected from the group consisting of '-biphenyltetracarboxylic dianhydride (hereinafter referred to as “specific tetracarboxylic dianhydride”). Specific tetracarboxylic dianhydrides include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,5-tricarboxy Cyclopentylacetic acid dianhydride, 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 5- (2,5-dioxotetrahydrofuranyl) ) -3-Methyl-3-cyclohexene-1,2-dicarboxylic anhydride, cis-3,7-dibutylcycloocta-1,5-diene-1,2,5,6-tetracarboxylic dianhydride 3,5,6-tricarbonyl-2-carboxynorbornane-2: 3,5: 6-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, 1,3,3a, 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 Acid dianhydride, 3-oxabicyclo [3.2.1] octane-2, - dione-6-spiro-3 '- (tetrahydrofuran-2', 5'-dione), the following formula (T-5) of the compounds represented by the above formula (T-I) ~ (T-7)

Of the compounds represented by the formula (T-II), the following formula (T-8)

And at least one selected from the group consisting of a compound represented by the formula: pyromellitic dianhydride and 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride, From the viewpoint that it can be expressed, more preferably 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2, 3,5-tricarboxycyclopentylacetic acid dianhydride, 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 1,3,3a , 4,5,9b-Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, cis-3,7-dibutylsi Loocta-1,5-diene-1,2,5,6-tetracarboxylic dianhydride, 3,5,6-tricarbonyl-2-carboxynorbornane-2: 3,5: 6-dianhydride, 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), a compound represented by the above formula (T-5), A tetracarboxylic dianhydride containing at least one selected from the group consisting of pyromellitic dianhydride and 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride, particularly preferably 1,2 , 3,4-Cyclobutanetetracarboxylic acid Anhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -At least one selected from the group consisting of naphtho [1,2-c] furan-1,3-dione and pyromellitic dianhydride.
Other preferable tetracarboxylic dianhydrides that can be used in combination with the specific tetracarboxylic dianhydride include, for example, butanetetracarboxylic dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride Products, 3,3 ′, 4,4′-biphenylsulfonetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, and the like.
The tetracarboxylic dianhydride used for synthesizing the polyamic acid in the liquid crystal aligning agent of the present invention, the specific tetracarboxylic dianhydride as described above is 60 mol% or more based on the total tetracarboxylic dianhydride. It is preferable that it is included, and it is more preferable that 80 mol% or more is included.

<Diamine>
The diamine used for synthesizing a preferable polyamic acid in the liquid crystal aligning agent of the present invention is a compound having the structure represented by the above formula (A) and two amino groups (hereinafter referred to as “compound (A)”). Is included.
As the compound (A), a compound having the structure represented by the above formula (A-1) and two amino groups (hereinafter referred to as “compound (A-1)”), and the above formula (A-2) And a compound having a structure represented by the above formula (A-3) and a compound having two amino groups (hereinafter referred to as “compound (A-2)”) (hereinafter referred to as “compound (A-2)”). It is preferably at least one selected from the group consisting of “compound (A-3)”. R ^a in the above formula (A-1) is preferably a halogen atom, and more preferably a fluorine atom. n is preferably 0 or 1. R ^b and R ^c in the formulas (A-2) and (A-3) are each preferably a hydrogen atom or a halogen atom, and more preferably a hydrogen atom or a fluorine atom.
Examples of the compound (A-1) include the following formula (A-1-1)

(In formula (A-1-1), R ^a and n have the same meanings as in formula (A-1), and Y ^a is a single bond or an arylene group having 6 to 10 carbon atoms. )
The compound etc. which are represented by these can be mentioned. Examples of the arylene group having 6 to 10 carbon atoms of Y ^{a in} the above formula (A-1-1) include a 1,4-phenylene group and a naphthalene-1,5-ene group. Specific examples of the compound represented by the above formula (A-1-1) include 2,6-diaminobenzothiazole, 2,7-diaminobenzothiazole, 2- (4-aminophenyl) -6-aminobenzo, for example. Examples include thiazole and 2- (4-aminophenyl) -7-aminobenzothiazole.
Examples of the compounds (A-2) and (A-3) include the following formulas (A-2-1) and (A-3-1)

(In the formulas (A-2-1) and (A-3-1), R ^b and R ^c have the same meanings as in the formula (A-2) or (A-3), respectively, and Y ^b And Y ^c are each independently a single bond or an arylene group having 6 to 10 carbon atoms.)
The compound etc. which are represented by each of these can be mentioned. In the above formulas (A-2-1) and (A-3-1), examples of the arylene group having 6 to 10 carbon atoms of Y ^b and Y ^c include a 1,4-phenylene group and naphthalene-1,5, respectively. -An ene group etc. can be mentioned. Specific examples of the compound represented by the formula (A-2-1) include 2,6-diaminobenzo [1,2-d: 4,5-d ′] bisthiazole, 2,6-bis ( 4-aminophenyl) benzo [1,2-d: 4,5-d ′] bisthiazole and the like;
Specific examples of the compound represented by the formula (A-3-1) include 2,6-diaminobenzo [1,2-d: 5,4-d ′] bisthiazole, 2,6-bis ( 4-aminophenyl) benzo [1,2-d: 5,4-d ′] bisthiazole and the like can be exemplified.
Diamines used to synthesize the preferred polyamic acid in the liquid crystal aligning agent of the present invention comprise a compound represented by the above-mentioned compound (A) and below the formula (D-III), also with these only Of course, these may be used in combination with other diamines.
Examples of other diamines that can be used here include aromatic diamines, aliphatic diamines, alicyclic diamines, diamines having two primary amino groups in the molecule and nitrogen atoms other than the primary amino groups, and mono-substituted Examples thereof include phenylenediamine and diaminoorganosiloxane.

  Examples of the aromatic diamine 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, 5-amino-1- (4′-aminophenyl) -1,3,3-trimethylindane, 6-amino-1- (4′-aminophenyl) -1,3,3- Trimethylindane, 3,4'-diaminodiphenyl ether, 3,3'-diaminobenzophenone, 3,4'-dia Nobenzophenone, 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, 9,9-bis (4-aminophenyl) -10-hydroanthracene, 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-phenyleneisopropylidene) bisaniline, 2,2'-bis [4- (4-amino-2-trifluoromethylphenoxy) phenyl] hexafluoro Propane, 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl, 4,4′-bis [(4-amino-2-trifluoromethyl) phenoxy] -octafluorobiphenyl, di (4 -Aminophenyl) benzidine, 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.)
A compound represented by each of
Examples of the aliphatic diamine include 1,1-metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, and nonamethylenediamine;
Examples of the alicyclic diamine include 1,4-diaminocyclohexane, isophorone diamine, tetrahydrodicyclopentadienylenediamine, tricyclo [6.2.1.0 ^2,7 ] -undecylenedimethyl diamine, 4,4 ′. -Methylene bis (cyclohexylamine), 1,3-bis (aminomethyl) cyclohexane and the like;
Examples of the diamine having two primary amino groups in the molecule and a nitrogen atom other than the primary amino group include 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, , 6-Diamino-2-vinyl-s-triazine, 2,4-diamino-5-phenylthiazole, 2,6-diaminopurine, 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, 1- (3,5-diaminophenyl) -3-decylsuccinimide, 1- (3,5-diaminophenyl) -3-octadecylsuccinimide, the following formula (DI)

(In formula (DI), R ⁵ is a monovalent organic group having a ring structure containing a nitrogen atom selected from pyridine, pyrimidine, triazine, piperidine and piperazine, and X ¹ is a divalent organic group. R ⁶ is an alkyl group having 1 to 4 carbon atoms, and a1 is an integer of 0 to 3.)
A compound represented by formula (D-II):

(In Formula (D-II), R ⁷ is a divalent organic group having a ring structure containing a nitrogen atom selected from pyridine, pyrimidine, triazine, piperidine and piperazine, and X ² is a divalent organic group, respectively. A plurality of X ² may be the same or different, R ⁸ is an alkyl group having 1 to 4 carbon atoms, and a2 is an integer of 0 to 3 respectively. is there.)
A compound represented by:
Examples of the mono-substituted phenylenediamine include the following formula (D-III)

(In the formula (D-III), R ⁹ represents —O—, —COO— ^* , —OCO— ^* , —NHCO— ^* , —CONH— ^* (in the above, the bond indicated by “*” is R ¹⁰ is bonded to R ¹⁰ ) or —CO—, and R ¹⁰ is a monovalent organic group or carbon having a skeleton or group selected from a steroid skeleton, a trifluoromethylphenyl group, a trifluoromethoxyphenyl group, and a fluorophenyl group An alkyl group having 6 to 30 carbon atoms, R ¹¹ is an alkyl group having 1 to 4 carbon atoms, and a3 is an integer of 0 to 3.)
A compound represented by:
Examples of the diaminoorganosiloxane include the following formula (D-IV):

(In the formula (D-IV), each R ¹² is a hydrocarbon group having 1 to 12 carbon atoms, and a plurality of R ¹² may be the same or different, and p is each 1 is an integer of 1 to 3, and q is an integer of 1 to 20.)
And the like can be mentioned respectively. These diamines can be used alone or in combination of two or more.
The benzene ring of the aromatic diamine may be substituted with one or two or more alkyl groups having 1 to 4 carbon atoms (preferably a methyl group). In the above formulas (DI), (D-II) and (D-III), R ⁶ , R ⁸ and R ¹¹ are each preferably a methyl group, and a1, a2 and a3 are each 0 Or it is preferable that it is 1, and it is more preferable that it is 0.
The steroid skeleton in R ¹⁰ of the above formula (D-III) refers to a structure composed of a cyclopentano-perhydrophenanthrene nucleus or a skeleton in which one or more of its carbon-carbon bonds are double bonds. As the monovalent organic group of R ¹⁰ having such a steroid skeleton, those having 17 to 51 carbon atoms are preferable, and those having 17 to 29 carbon atoms are more preferable.
Specific examples of R ¹⁰ having such a steroid skeleton include, for example, cholestane-3-yl group, cholesta-5-en-3-yl group, cholesta-24-en-3-yl group, cholesta-5,24-diene. A -3-yl group, a lanostane-3-yl group, etc. can be mentioned.

  Specific examples of the compound represented by the formula (DI) include, for example, the following formula (D-6)

A compound represented by:
Specific examples of the compound represented by the formula (D-II) include, for example, the following formula (D-7)

A compound represented by:
Specific examples of the compound represented by the formula (D-III) include, for example, the following formulas (D-8) to (D-16):

The compounds represented by each of the above can be mentioned respectively.
Other diamines used for synthesizing a preferred polyamic acid in the liquid crystal aligning agent of the present invention include p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylsulfide, , 5-diaminonaphthalene, 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- Chlohexanediamine, 4,4′-methylenebis (cyclohexylamine), 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, the above formula (D-1) ˜ A compound represented by each of (D-5), 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminoacridine, represented by the above formula (D-6) A compound represented by the above formula (D-7), a compound represented by the above formula (D-III), and 1,3-bis (-3-diaminopropyl) tetramethyldisiloxane. It is preferable to use at least one selected. The compound represented by the above formula (D-III) is essential.
As the compound represented by the above formula (D-III), in the above formula (D-III), R ⁹ is —O— or —COO— ^* (however, a bond with “*” attached to R ¹⁰ And a compound in which R ¹⁰ is a monovalent organic group having a steroid skeleton is preferable, and compounds represented by the above formulas (D-8) to (D-13) are particularly preferable.

Other diamines include p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether, bis [4- (4-aminophenoxy) phenyl] sulfone, and the above formula (D-III). It is preferable that it contains at least one selected from the group consisting of the following compounds, particularly p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether and bis [4- (4-aminophenoxy). ) At least one selected from the group consisting of phenyl] sulfone,
A compound represented by the above formula (D-III);
It is preferable that it contains.
The diamine used for synthesizing a preferred polyamic acid in the liquid crystal aligning agent of the present invention preferably contains 1 mol% or more of the compound (A) relative to the total diamine, and contains 5 to 90 mol%. More preferably, it is more preferably 10 to 80 mol%, and particularly preferably 15 to 30 mol%.
The diamine used for synthesizing a preferred polyamic acid in the liquid crystal aligning agent of the present invention preferably contains 1 to 50 mol% of the compound represented by the above formula (D-III) with respect to the total diamine. More preferably 5 to 30 mol% is contained.
Diamines used for synthesizing preferred polyamic acids in the liquid crystal aligning agent of the present invention are p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether and bis [4- (4-aminophenoxy). It is preferable that at least one selected from the group consisting of phenyl] sulfone is contained in an amount of 30 to 90 mol%, more preferably 40 to 80 mol%, based on all diamines.

<Synthesis of polyamic acid>
A preferable polyamic acid in the liquid crystal aligning agent of the present invention can be obtained by reacting the tetracarboxylic dianhydride as described above with a diamine containing the compound (A).
The ratio of the tetracarboxylic dianhydride and the diamine used in the polyamic acid synthesis reaction is 0.2 to 2 for the tetracarboxylic dianhydride acid anhydride group to 1 equivalent of the amino group of the diamine. The ratio which becomes an equivalent is preferable, More preferably, it is a ratio which becomes 0.7-1.2 equivalent.
The polyamic acid is preferably synthesized in an organic solvent, preferably at −20 ° C. to 150 ° C., more preferably at 0 to 100 ° C., preferably 1 to 72 hours, more preferably 3 to 48 hours. Done. Here, the organic solvent is not particularly limited as long as it can dissolve the produced polyamic acid. For example, 1-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, 3-butoxy Amide compounds such as -N, N-dimethylpropanamide, 3-methoxy-N, N-dimethylpropanamide, 3-hexyloxy-N, N-dimethylpropanamide, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea, hexa Examples include aprotic compounds such as methylphosphotriamide; phenolic compounds such as m-cresol, xylenol, phenol, and halogenated phenol. The amount of organic solvent used (α) is usually 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 of the reaction solution (α + β). An amount is preferred. When the organic solvent is used in combination with a poor solvent described below, the amount of organic solvent used (α) is understood as meaning the total amount of the organic solvent and the poor solvent. It is.

Alcohols, ketones, esters, ethers, halogenated hydrocarbons, hydrocarbons, etc., which are generally believed to be poor solvents for polyamic acids, may be used in combination with the organic solvent as long as the resulting polyamic acid does not precipitate. Good. Specific examples of such poor solvents include, for example, methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, 4-hydroxy-4-methyl-2-pentanone, 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, malon Acid diethyl, diethyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i Propyl ether, ethylene glycol-n-butyl 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, diisobutyl ketone, isoamylpropionate, isoamylisobutyrate And di isopentyl ether, and the like.
When the organic solvent and the poor solvent as described above are used in combination, the use ratio of the poor solvent can be appropriately set within a range in which the generated polyamic acid does not precipitate, but with respect to the total amount of the organic solvent and the poor solvent. It is preferably 30% by weight or less, and more preferably 20% 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.
When polyamic acid is dehydrated and cyclized into a polyimide, the above reaction solution may be directly subjected to dehydration and cyclization reaction, or may be subjected to dehydration and cyclization reaction after isolating the polyamic acid contained in the reaction solution. Alternatively, the isolated polyamic acid may be purified and then subjected to a dehydration ring closure reaction.
The polyamic acid is 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 off the organic solvent in the reaction solution under reduced pressure using an evaporator. Can be performed. 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.

<Polyimide>
A preferred polyimide in the liquid crystal aligning agent of the present invention can be obtained by dehydrating and ring-closing the polyamic acid as described above.
The polyimide in the liquid crystal aligning agent of the present invention may be a completely imidized product obtained by dehydrating and ring-closing all of the amic acid structure possessed by the polyamic acid that is the precursor, or only a part of the amic acid structure may be dehydrating and ring-closing. Alternatively, it may be a partially imidized product in which an amic acid structure and an imide ring structure coexist.
The polyimide contained in the liquid crystal aligning agent of the present invention preferably has an imidation ratio of 40 mol% or more, and more preferably 80 mol% or more. By using a polyimide having an imidation ratio of 40 mol% or more, a liquid crystal aligning agent capable of forming a liquid crystal alignment film having better charge leakage properties can be obtained.
The said imidation rate represents the ratio which the number of the imide ring structure accounts with respect to the sum total of the number of the amic acid structures of polyimide, and the number of imide ring structures in percentage. At this time, a part of the imide ring may be an isoimide ring. The imidation rate is as follows from the result of measuring ¹ H-NMR at room temperature (for example, 25 ° C.) using tetramethylsilane as a reference substance by dissolving polyimide in a suitable deuterated solvent (for example, deuterated dimethyl sulfoxide). It can obtain | require by Numerical formula (1).

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

(In Formula (1), A ¹ is a peak area derived from protons of NH groups appearing near a chemical shift of 10 ppm, A ² is a peak area derived from other protons, and α is a polyimide precursor (polyamic acid). The number ratio of other protons to one proton of NH group in
The dehydration ring closure of the polyamic acid is preferably performed by (i) a method of heating the polyamic acid, or (ii) dissolving the polyamic acid in an organic solvent, and adding a dehydrating agent and a dehydration ring closure catalyst to this solution as necessary. This is done by heating.

The reaction temperature in the method (i) of heating the polyamic acid is preferably 50 to 200 ° C, more preferably 60 to 170 ° C. The reaction time is preferably 1 to 8 hours, more preferably 3 to 5 hours. 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 resulting polyimide may decrease.
On the other hand, 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 is used as the dehydrating agent. Can do. Although the usage-amount of a dehydrating agent is based on the imidation ratio desired, it is preferable to set it as 0.01-20 mol with respect to 1 mol of the amic acid structure 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. It is preferable that the usage-amount of a dehydration ring-closing catalyst shall be 0.01-10 mol with respect to 1 mol of dehydrating agents to be used. The imidation rate can be increased as the amount of the above dehydrating agent and dehydrating ring-closing agent increases. 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 1 to 8 hours, more preferably 3 to 5 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 above method (ii), a reaction solution containing polyimide is obtained. This reaction solution may be used as it is 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. It may be used for the preparation of a liquid crystal aligning agent or may be used for the preparation of a liquid crystal aligning agent after purifying the isolated polyimide. In order to remove the dehydrating agent and the dehydration ring closure catalyst from the reaction solution, for example, a method such as solvent replacement can be applied. The isolation and purification of the polyimide can be performed by performing the same operation as described above as the isolation and purification method of the polyamic acid.

-End-modified polymer-
The polyamic acid and the polyimide contained in the liquid crystal aligning agent of the present invention may be terminal-modified polymers each having a molecular weight adjusted. By using the terminal-modified polymer, the coating properties of the liquid crystal aligning agent can be further improved without impairing the effects of the present invention. Such a terminal-modified polymer can be obtained by adding a molecular weight modifier to a polymerization reaction system when synthesizing a polyamic acid. Examples of molecular weight regulators include acid monoanhydrides, monoamine compounds, monoisocyanate compounds, and the like.
Examples of the acid monoanhydride include maleic anhydride, phthalic anhydride, itaconic anhydride, n-decyl succinic anhydride, n-dodecyl succinic anhydride, n-tetradecyl succinic anhydride, n -Hexadecyl succinic acid anhydride etc. can be mentioned. 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, etc. it can. Examples of the monoisocyanate compound include phenyl isocyanate and naphthyl isocyanate.
The use ratio of the molecular weight modifier is preferably 20 parts by weight or less, more preferably 10 parts by weight or less, with respect to 100 parts by weight of the total of tetracarboxylic dianhydride and diamine used when synthesizing the polyamic acid. .
-Solution viscosity-
The polyamic acid and polyimide obtained as described above preferably have a solution viscosity of 20 to 800 mPa · s, and a solution viscosity of 30 to 500 mPa · s, respectively, when a solution having a concentration of 10% by weight is obtained. It is more preferable that it has.
The solution viscosity (mPa · s) of the polymer is a value measured at 25 ° C. using an E-type rotational viscometer for a polymer solution having a concentration of 10% by weight prepared using a good solvent for the polymer. .

<Other additives>
Although the liquid crystal aligning agent of this invention contains the above specific polymers as an essential component, it may contain the other component as needed. Examples of such other components include other polymers and adhesion improvers.
These other polymers can be used to improve solution and electrical properties. Such other polymer is a polymer other than the specific polymer. For example, a polyamic acid obtained by reacting a tetracarboxylic dianhydride and a diamine not containing the compound (A) (hereinafter referred to as “other polyamic acid”). ), A polyimide obtained by dehydrating and ring-closing the polyamic acid (hereinafter referred to as “other polyimide”), polyamic acid ester, polyester, polyamide, polysiloxane, cellulose derivative, polyacetal, polystyrene derivative, poly (styrene- Phenylmaleimide) derivatives, poly (meth) acrylates and the like. Of these, other polymic acids or other polyimides are preferred.
The proportion of the other polymer used is preferably 90% by weight or less, more preferably 85% by weight with respect to the total of the polymers (the total of specific polymers and other polymers; the same shall apply hereinafter). % Or less.

The said adhesive improvement agent can be used in order to improve the adhesiveness with respect to the substrate surface of the liquid crystal aligning film formed. Examples of the adhesion improver include a compound having at least one epoxy group in the molecule (hereinafter referred to as “epoxy compound”), a functional silane compound, and the like.
Examples of the epoxy compound 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, N, N, N ′, N′-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N— Diglycidylaminomethyl) cyclohexane, N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane, 3- (N-allyl-N-glycidyl) amino B pills trimethoxysilane, 3- (N, N- diglycidyl) and an amino propyl trimethoxy silane.
The use ratio of the epoxy compound as described above is preferably 40 parts by weight or less, 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 include oxyethylene) -3-aminopropyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, and the like.
The use ratio of the functional silane compound as described above is preferably 2 parts by weight or less, more preferably 0.01 to 0.2 parts by weight with respect to 100 parts by weight of the total polymer.

The liquid crystal aligning agent of the present invention is constituted by dissolving the specific polymer as described above and other additives optionally blended as required, preferably dissolved in an organic solvent.
Examples of the organic solvent that can be used in the liquid crystal aligning agent of the present invention include 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, 3-butoxy-N, N-dimethylpropanamide, 3-methoxy-N, N-dimethylpropanamide, 3-hexyloxy-N, N-dimethylpropanamide and the like can be mentioned.

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) is appropriately selected in consideration of viscosity, volatility, and the like. The range is preferably 1 to 10% by weight. That is, the liquid crystal aligning agent of the present invention is applied to the substrate surface as described later, and preferably, when heated, a coating film that becomes a liquid crystal aligning film is formed, but the solid content concentration is less than 1% by weight. In this case, the film thickness of the coating film becomes too small to obtain a good liquid crystal alignment film. On the other hand, when the solid content concentration exceeds 10% by weight, the film thickness of the coating film becomes excessive. Thus, a good liquid crystal alignment film cannot be obtained, and the viscosity of the liquid crystal aligning agent increases, resulting in poor coating properties.
The particularly preferable range of the solid content concentration varies depending on the method used when the liquid crystal aligning agent is applied to the substrate. For example, when the spin coating method is used, the solid content concentration is particularly preferably in the range of 1.5 to 4.5% by weight. 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 the time of preparing the liquid crystal aligning agent of this invention becomes like this. Preferably it is 0-200 degreeC, More preferably, it is 20-60 degreeC.

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.
Preferred operation modes in the liquid crystal display element of the present invention include TN type, VA type and IPS type.
The liquid crystal display element of the present invention can be produced, for example, by the following steps (1) to (3). In step (1), the substrate to be used varies depending on the desired operation mode. Steps (2) and (3) are common to each operation mode.
(1) First, the liquid crystal aligning agent of this invention is apply | coated on a board | substrate, Then, a coating film is formed on a board | substrate by heating an application surface.
(1-1) In the case of manufacturing a TN type or VA type liquid crystal display element, the present invention is applied to each of the transparent conductive film forming surfaces of a pair of two substrates provided with a patterned transparent conductive film. The liquid crystal aligning agent is preferably applied by an offset printing method, a roll coater method, a spin coating method or an ink jet printing method to form a coating film. Here, as the substrate, for example, a glass such as float glass or soda glass; a transparent substrate made of a plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, or poly (alicyclic olefin) can be used. As a transparent conductive film provided on one surface of a substrate, a 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 ), etc. In order to obtain a patterned transparent conductive film which can be used, for example, a method of forming a pattern by photo-etching after forming a transparent conductive film without a pattern, a mask having a desired pattern when forming the transparent conductive film It is possible to use a method using 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 or functional titanium is formed on the surface of the substrate surface on which the coating film is to be formed. You may give the pretreatment which apply | coats a compound etc. previously.
After applying a liquid crystal aligning agent to such a substrate, preheating (pre-baking) is preferably performed for the purpose of preventing dripping. 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 0.25 to 10 minutes, and more preferably 0.5 to 5 minutes. After pre-baking, the solvent in the film is completely removed, and if the polymer contained in the liquid crystal aligning agent has an amic acid structure, it is calcined (post-baked) for the purpose of thermal imidization if necessary Is implemented. The post-bake temperature is preferably 80 to 300 ° C, more preferably 120 to 250 ° C. The post-bake time is preferably 5 to 200 minutes, more preferably 10 to 100 minutes.
The film thickness of the coating film thus formed is preferably 0.001 to 1 μm, more preferably 0.005 to 0.5 μm.

(1-2) On the other hand, when manufacturing an IPS type liquid crystal display element, the conductive film forming surface of the substrate provided with the comb-shaped transparent conductive film and the counter substrate provided with no conductive film One surface is coated with the liquid crystal aligning agent of the present invention preferably by an offset printing method, a roll coater method, a spin coating method or an ink jet printing method, and then preferably each coated surface is heated (prebaked and postbaked). To form a coating film.
The material used for the substrate and the transparent conductive film, the patterning method of the transparent conductive film, the pretreatment of the substrate, the pre-bake and post-bake conditions after coating, and the film thickness of the coating film to be formed are as described in (1-1). ).
In both cases (1-1) and (1-2), the liquid crystal aligning agent of the present invention forms a coating film that becomes a liquid crystal aligning film by removing the organic solvent after coating. When the polymer contained in the alignment agent is a polyamic acid or a polyimide having both an imide ring structure and an amic acid structure, the dehydration cyclization reaction proceeds by further heating after the coating film is formed, and the polymer is further imidized. It may be a coated film.

(2) The coating film formed as described above can be used as it is as a liquid crystal alignment film for a VA liquid crystal display element. May be applied.
When the coating film formed as described above is used as a liquid crystal alignment film for a TN-type or IPS-type liquid crystal display element, the coating film surface is subjected to rubbing treatment, whereby the liquid crystal molecular alignment ability is applied to the coating film. To give a liquid crystal alignment film.
The rubbing treatment can be performed by rubbing the coating film surface in a certain direction with a roll wound with a cloth made of fibers such as nylon, rayon, and cotton.
Further, for the liquid crystal alignment film formed as described above, for example, as disclosed in Patent Document 4 (Japanese Patent Laid-Open No. 6-222366) and Patent Document 5 (Japanese Patent Laid-Open No. 6-281937). A process for changing the pretilt angle of a partial region of the liquid crystal alignment film by irradiating a part of the liquid crystal alignment film with ultraviolet rays, or a liquid crystal as disclosed in Patent Document 6 (Japanese Patent Laid-Open No. 5-105444). After a resist film is formed on a part of the alignment film surface, a rubbing process is performed in a direction different from the previous rubbing process, and then the resist film is removed, so that the liquid crystal alignment film has different liquid crystal alignment capabilities for each region. By doing so, it is possible to improve the visual field characteristics of the liquid crystal display element obtained.

(3) The pair of substrates on which the liquid crystal alignment films are formed as described above are arranged to face each other through a gap (cell gap) so that the rubbing directions of the liquid crystal alignment films of the two substrates are orthogonal or antiparallel. Then, the peripheral portions of the two substrates are bonded using a sealing agent, liquid crystal is injected and filled into the cell gap defined by the substrate surface and the sealing agent, and the injection hole is sealed to form a liquid crystal cell. And a liquid crystal display element can be obtained by bonding a polarizing plate on the outer surface of a liquid crystal cell so that the polarization direction thereof coincides with or is orthogonal to the rubbing direction of a liquid crystal alignment film formed on each substrate. 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 crystals and smectic liquid crystals. Among them, nematic liquid crystals are preferable. For example, Schiff base liquid crystals, azoxy liquid crystals, biphenyl liquid crystals, phenylcyclohexane liquid crystals, ester liquid crystals, terphenyl liquid crystals. Liquid crystal, biphenylcyclohexane liquid crystal, pyrimidine liquid crystal, dioxane liquid crystal, bicyclooctane liquid crystal, cubane liquid crystal, or the like can be used. Further, cholesteric liquid crystals such as cholestyl chloride, cholesteryl nonate, cholesteryl carbonate, etc .; chiral products such as those sold under the trade names “C-15” and “CB-15” (manufactured by Merck) Agent: Ferroelectric liquid crystal such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate may be added and used.
As a polarizing plate to be bonded to the outer surface of the liquid crystal cell, a polarizing film or an H film itself in which a polarizing film called “H film” in which iodine is absorbed while stretching and aligning polyvinyl alcohol is sandwiched between cellulose acetate protective films The polarizing plate which consists of can be mentioned.
The liquid crystal display element of the present invention manufactured as described above does not deteriorate in display performance even when it is continuously driven for a long time as compared with a conventionally known liquid crystal display element. Has an advantage that the light leakage of the backlight, which may be caused by the poor alignment of the liquid crystal due to the thermal deterioration of the liquid crystal alignment film, does not occur.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.
Moreover, the solution viscosity of the polymer in the synthesis example is a value measured at 25 ° C. using an E-type viscometer.
<Synthesis of Compound (A)>
Synthesis Example 1 (Synthesis of 2,6-diaminobenzothiazole)
The synthetic raw material 2-amino-6-nitrobenzothiazole used the product of Tokyo Chemical Industry Co., Ltd. as it was. 97.6 g (0.50 mol) of 2-amino-6-nitrobenzothiazole was dissolved in 3,000 mL of ethanol, 5 wt% palladium / carbon 90 g was added, and the mixture was stirred at 70 ° C. for 1 hour under a nitrogen atmosphere. Thereafter, 153 mL of hydrazine monohydrate was added, and the reaction was performed by stirring for 6 hours under reflux in a nitrogen stream. After completion of the reaction, palladium / carbon was removed by Celite filtration, and the solvent was removed from the filtrate. The obtained solid was sufficiently washed with distilled water and dried to obtain 44.8 g (54.0%) of 2,6-diaminobenzothiazole, which was the target product.
This synthesis operation was repeated on the above-described synthesis scale to secure an amount of 2,6-diaminobenzothiazole necessary for the synthesis of the following polymers.

<Synthesis of specific polymer>
Synthesis Example 2 (Polyimide Synthesis 1)
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 84 g (0.78 mol) as diamine, 16.5 g (0.1 mol) of 2,6-diaminobenzothiazole, 32 g (0.10 mol) of 2,2-ditrifluoromethyl-4,4-diaminobiphenyl and 3,6-bis (4-aminobenzoyloxy) ) 6.4 g (0.010 mol) of cholestane and 2.8 g (0.03 mol) of aniline as a monoamine were added to N-methyl-2-pyrrolidone (NMP) 1 It was dissolved in 200 g, by performing a 9-hour reaction at 60 ° C., to obtain a solution containing a polyamic acid. 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.
Next, 2,400 g of NMP was added to the polyamic acid solution obtained above, 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 cyclization reaction, the solvent in the system was replaced with new γ-butyrolactone (the pyridine and acetic anhydride used in the dehydration cyclization reaction were removed from the system by this solvent replacement operation. The same applies hereinafter), and then concentrated. As a result, about 3,700 g of a solution containing 10% by weight of polyimide (PI-1) having an imidation ratio of about 95% was obtained. The solution viscosity of this polyimide solution was 69 mPa · s.

Synthesis example 3 (polyimide synthesis 2)
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 (0.77 mol) as diamine, 2, 16.5 g (0.1 mol) of 6-diaminobenzothiazole, 25 g (0.10 mol) of 1,3-bis (3-aminopropyl) tetramethyldisiloxane and 3,6-bis (4-aminobenzoyloxy) 9.6 g (0.015 mol) of cholestane and 2.8 g (0.030 mol) of aniline as a monoamine are dissolved in 960 g of NMP, and 6 hours at 60 ° C. Performing response, to obtain a solution containing a polyamic acid. 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 reaction was performed at 110 ° C. for 4 hours. After the dehydration cyclization reaction, the solvent in the system was replaced with fresh γ-butyrolactone, and then concentrated to obtain about 3,800 g of a solution containing 10% by weight of polyimide (PI-2) having an imidization ratio of about 88%. Got. The solution viscosity of this polyimide solution was 55 mPa · s.

Synthesis example 4 (polyimide synthesis 3)
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 (0.72 mol) as diamine, 16.5 g (0.1 mol) of 6-diaminobenzothiazole, 25 g (0.10 mol) of 1,3-bis (3-aminopropyl) tetramethyldisiloxane and 4- (4′-trifluoromethyloxybenzoyloxy) ) 35 g (0.080 mol) of cyclohexyl-3,5-diaminobenzoate and 2.8 g (0.030 mol) of aniline as monoamine Was dissolved in NMP1,271g, it carried out 6 hours at 60 ° C., to obtain a solution containing a polyamic acid. 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, 2,500 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 reaction 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, and then concentrated to obtain about 3,800 g of a solution containing 10% by weight of polyimide (PI-3) having an imidization ratio of about 96%. Got. The solution viscosity of this polyimide solution was 55 mPa · s.

Synthesis Example 5 (Polyimide Synthesis 4)
110 g (0.50 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride and 43 g (0.30 mol) of p-phenylenediamine as diamine, 2,6-diaminobenzothiazole 16 0.5 g (0.1 mol) and 52 g (0.10 mol) of 3 (3,5-diaminobenzoyloxy) cholestane were dissolved in 830 g of NMP and reacted at 60 ° C. for 6 hours to prepare a solution containing polyamic acid. Obtained. 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 20% by weight was 2,200 mPa · s.
Next, 1,500 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 reaction was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with new NMP and then concentrated to obtain about 2,700 g of a solution containing 7% by weight of polyimide (PI-4) having an imidization ratio of about 50%. It was. The solution viscosity of this polyimide solution was 30 mPa · s.

Synthesis Example 6 (Polyimide Synthesis 5)
110 g (0.50 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride and 49 g (0.35 mol) of p-phenylenediamine as diamine, 2,6-diaminobenzothiazole 16 0.5 g (0.1 mol) and 26 g (0.05 mol) of 3 (3,5-diaminobenzoyloxy) cholestane were dissolved in 750 g of NMP and reacted at 60 ° C. for 6 hours to prepare a solution containing polyamic acid. Obtained. 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 20% by weight was 2,200 mPa · s.
Next, 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 reaction was performed at 110 ° C. for 4 hours. After the dehydration cyclization reaction, the solvent in the system was replaced with new NMP to obtain about 2,500 g of a solution containing 7% by weight of polyimide (PI-5) having an imidization ratio of about 50%. The solution viscosity of this polyimide solution was 50 mPa · s.

Synthesis Example 7 (Polyimide Synthesis 6)
110 g (0.50 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride and 38 g (0.25 mol) of p-phenylenediamine as diamine, 2,6-diaminobenzothiazole 16 0.5 g (0.1 mol), 4,4′-diaminodiphenylmethane 20 g (0.1 mol) and 3 (3,5-diaminobenzoyloxy) cholestane 26 g (0.05 mol) were dissolved in 810 g of NMP. The solution was reacted for 6 hours to obtain a solution containing polyamic acid. 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 7% by weight was 65 mPa · s.
Next, 1,900 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 reaction was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with new NMP to obtain about 1,400 g of a solution containing 15% by weight of polyimide (PI-6) having an imidation ratio of about 80%. A small amount of this polyimide solution was taken, and NMP was added to measure the solution viscosity as a solution having a polyimide concentration of 10% by weight. The solution viscosity was 90 mPa · s.

Synthesis Example 8 (Polyimide Synthesis 7 , Reference Example )
110 g (0.50 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride and 43 g (0.40 mol) of p-phenylenediamine and 2,6-diaminobenzothiazole 16 as diamine 0.5 g (0.1 mol) was dissolved in 1,800 g of NMP and reacted at 60 ° C. for 6 hours to obtain a solution containing polyamic acid. 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 70 mPa · s.
Next, 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 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, and then concentrated to obtain about 1,200 g of a solution containing 15% by weight of polyimide (PI-7) having an imidization ratio of about 89%. Got. A small amount of this polyimide solution was taken, and γ-butyrolactone was added to measure the viscosity of the solution as a solution having a polyimide concentration of 10% by weight of 150 mPa · s.

Synthesis Example 9 (Polyimide Synthesis 8 , Reference Example )
165 g (0.75 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 (78 g, 0.25 mol) and p-phenylenediamine (32 g, 0.30 mol) as a diamine, 16.5 g (0.1 mol) of 2,6-diaminobenzothiazole, 80 g (0.4 mol) of 4,4′-diaminodiphenyl ether and 85 g (0.20) of bis {4- (4-aminophenoxy) phenyl} sulfone Mol) was dissolved in 2,600 g of NMP and reacted at 60 ° C. for 6 hours to obtain a solution containing polyamic acid. 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 400 mPa · s.
Next, 1,800 g of NMP was added to the obtained polyamic acid solution, 395 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 dehydration and cyclization reaction, the solvent in the system was replaced with fresh γ-butyrolactone, and then concentrated to obtain about 1,350 g of a solution containing 15% by weight of polyimide (PI-8) having an imidization ratio of about 85%. Got. A small amount of this polyimide solution was taken, and γ-butyrolactone was added to measure the solution viscosity as a solution having a polyimide concentration of 10% by weight. The solution viscosity was 90 mPa · s.

Synthesis Example 10 (Polyimide Synthesis 9 , Reference Example )
110 g (0.50 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride and 82.5 g (0.5 mol) of 2,6-diaminobenzothiazole as diamine were added to 1,800 g of NMP. And a reaction was carried out at 60 ° C. for 6 hours to obtain a solution containing polyamic acid. 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 65 mPa · s.
Next, 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 reaction was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with fresh γ-butyrolactone, and then concentrated to obtain about 1,100 g of a solution containing 15% by weight of polyimide (PI-9) having an imidization ratio of about 83%. Got. A small amount of this polyimide solution was taken, and γ-butyrolactone was added to measure the solution viscosity as a solution having a polyimide concentration of 10% by weight. The solution viscosity was 70 mPa · s.

Synthesis Example 11 (Polyimide Synthesis 10)
110 g (0.50 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride and 32 g (0.30 mol) of p-phenylenediamine as diamine, 2,6-diaminobenzothiazole 16 0.5 g (0.1 mol), 2,2′-bis (trifluoromethyl) benzene 16 g (0.050 mol) and 4,4′-diaminodiphenylmethane 11 g (0.050 mol) were dissolved in 2,000 g of NMP. The solution was reacted at 60 ° C. for 6 hours to obtain a solution containing polyamic acid. 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 480 mPa · s.
Next, 1,800 g of NMP was added to the obtained polyamic acid solution, 126 g of pyridine and 163 g of acetic anhydride were added, and dehydration ring closure reaction 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, and then concentrated to obtain about 1,300 g of a solution containing 15% by weight of polyimide (PI-10) having an imidization ratio of about 88%. Got. A small amount of this polyimide solution was taken, and γ-butyrolactone was added thereto, and the solution viscosity measured as a solution having a polyimide concentration of 10% by weight was 35 mPa · s.

<Synthesis of other polymers>
Synthesis Example 12 (Synthesis 1 of other polyamic acid)
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- By dissolving 200 g (1.0 mol) of diaminodiphenyl ether in a mixed solvent consisting of 230 g of NMP and 2,010 g of γ-butyrolactone, reacting at 40 ° C. for 3 hours, and then adding 1,350 g of γ-butyrolactone, About 3,500 g of a solution containing 10% by weight of acid (PA-1) was obtained. The solution viscosity of this polyamic acid solution was 200 mPa · s.
Synthesis Example 13 (Synthesis 2 of other polyamic acid)
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 -By dissolving 200 g (1.0 mol) of diaminodiphenylmethane in a mixed solvent consisting of 230 g of NMP and 2,100 g of γ-butyrolactone, reacting at 40 ° C for 3 hours, and then adding 1,350 g of γ-butyrolactone, About 3,500 g of a solution containing 10% by weight of polyamic acid (PA-2) was obtained. The solution viscosity of this polyamic acid solution was 125 mPa · s.

Synthesis Example 14 (Synthesis 3 of other polyamic acids)
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 composed of 370 g of NMP and 3,300 g of γ-butyrolactone, and reacted at 40 ° C. for 3 hours to obtain about 3,500 g of a solution containing 10% by weight of polyamic acid (PA-3). Obtained. The solution viscosity of this polyamic acid solution was 160 mPa · s.
Synthesis Example 15 (Synthesis 4 of other polyamic acid)
Pyromellitic anhydride 196 g (0.9 mol) and 1,2,3,4-cyclobutanetetracarboxylic dianhydride 19.6 g (0.1 mol) as tetracarboxylic dianhydride and p-phenylene as diamine 21.6 g of diamine and 180 g (0.8 mol) of 4,4′-diaminodiphenyl ether are dissolved in 2,400 g of NMP and reacted at 60 ° C. for 4 hours, thereby containing 10% by weight of polyamic acid (PA-4) About 2,400 g of a solution was obtained. The solution viscosity of this polyamic acid solution was 200 mPa · s.

Synthesis Example 16 (Synthesis 1 of other polyimides)
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, 2,2-ditrifluoromethyl-4,4-diaminobiphenyl 32 g (0.10 mol) and 3,6-bis (4-aminobenzoyloxy) cholestane 6.4 g (0.010 mol) and aniline as monoamine 2. 8 g (0.03 mol) was dissolved in 1,200 g of NMP and reacted at 60 ° C. for 9 hours to obtain a solution containing polyamic acid. 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.
Next, 2,400 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 reaction 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, and then concentrated to obtain about 3,700 g of a solution containing 10% by weight of polyimide (PI-11) having an imidation ratio of about 95%. Got. The solution viscosity of this polyimide solution was 69 mPa · s.

Synthesis Example 17 (Synthesis 2 of other polyimides)
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 8 as monoamine 0.1 g (0.030 mol) is dissolved in 960 g of NMP and reacted at 60 ° C. for 6 hours to obtain a solution containing polyamic acid. . 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 reaction 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 2,300 g of a solution containing 15% by weight of polyimide (PI-12) having an imidation ratio of about 95%. A small amount of this polyimide solution was taken, and γ-butyrolactone was added to measure the solution viscosity as a solution having a polyimide concentration of 10% by weight. The solution viscosity was 70 mPa · s.

Synthesis Example 18 (Synthesis 3 of other polyimides)
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 88 g (0.82 mol) as diamine, 1, 25 g (0.10 mol) of 3-bis (3-aminopropyl) tetramethyldisiloxane and 35 g (0.080 mol) of 4- (4′-trifluoromethyloxybenzoyloxy) cyclohexyl-3,5-diaminobenzoate and As a monoamine, 2.8 g (0.030 mol) of aniline is dissolved in 1,200 g of NMP and reacted at 60 ° C. for 6 hours. A solution containing polyamic acid was obtained. 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, 2,500 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 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, and then concentrated to obtain about 3,600 g of a solution containing 10% by weight of polyimide (PI-13) having an imidization ratio of about 96%. Got. The solution viscosity of this polyimide solution was 55 mPa · s.

Synthesis Example 19 (Synthesis 4 of other polyimides)
110 g (0.50 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride and 43 g (0.40 mol) of p-phenylenediamine and 3 (3,5-diaminobenzoyl) as diamine Oxy) cholestane 52 g (0.10 mol) was dissolved in NMP 830 g and reacted at 60 ° C. for 6 hours to obtain a solution containing polyamic acid. 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, 1,900 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 reaction was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with new NMP to obtain about 1,100 g of a solution containing 15% by weight of polyimide (PI-14) having an imidation ratio of about 50%. A small amount of this polyimide solution was collected, and NMP was added thereto to measure the solution viscosity as a solution having a polyimide concentration of 10% by weight, which was 47 mPa · s.

Synthesis Example 20 (Synthesis 5 of other polyimides)
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 NMP and reacted at 60 ° C. for 6 hours to obtain a solution containing polyamic acid. 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.
Next, 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 reaction was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with new NMP to obtain about 1,000 g of a solution containing 15% by weight of polyimide (PI-15) having an imidation ratio of about 50%. A small amount of this polyimide solution was taken, and NMP was added thereto to measure the solution viscosity as a solution having a polyimide concentration of 10% by weight, which was 85 mPa · s.

Synthesis Example 21 (Synthesis 6 of other polyimides)
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 NMP and reacted at 60 ° C. for 6 hours to obtain a solution containing polyamic acid. . 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, 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 reaction was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with new NMP to obtain about 1,050 g of a solution containing 15% by weight of polyimide (PI-16) having an imidation ratio of about 80%. A small amount of this polyimide solution was taken, and NMP was added to measure the solution viscosity as a solution having a polyimide concentration of 10% by weight, which was 87 mPa · s.

Synthesis Example 22 (Synthesis 7 of other polyimides)
110 g (0.50 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride and 54 g (0.50 mol) of p-phenylenediamine as diamine were dissolved in 1,800 g of NMP. Reaction was performed at 0 degreeC for 6 hours, and the solution containing a polyamic acid was obtained. 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 75 mPa · s.
Next, 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 reaction was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with fresh γ-butyrolactone, and then concentrated to obtain about 1,400 g of a solution containing 15% by weight of polyimide (PI-17) having an imidation ratio of about 91%. Got. A small amount of this polyimide solution was taken, and γ-butyrolactone was added to measure the viscosity of the solution as a solution having a polyimide concentration of 10% by weight of 150 mPa · s.

Synthesis Example 23 (Synthesis 8 of other polyimides)
165 g (0.75 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 (78 g, 0.25 mol) and 43 g (0.40 mol) of p-phenylenediamine as a diamine, 80 g (0.4 mol) of 4,4′-diaminodiphenyl ether and 85 g (0.20 mol) of bis {4- (4-aminophenoxy) phenyl} sulfone were dissolved in 2,600 g of NMP, and the reaction was performed at 60 ° C. for 6 hours. And a solution containing polyamic acid was obtained. 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, 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 reaction 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, and then concentrated to obtain about 2,700 g of a solution containing 15% by weight of polyimide (PI-18) having an imidization ratio of about 81%. Got. A small amount of this polyimide solution was taken, and γ-butyrolactone was added to measure the viscosity of the solution as a solution having a polyimide concentration of 10% by weight of 95 mPa · s.

Synthesis Example 24 (Synthesis 9 of other polyimides)
110 g (0.50 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride and 43 g (0.40 mol) of p-phenylenediamine as diamine, 2,2′-bis (tri Fluoromethyl) benzene (16 g, 0.050 mol) and 4,4′-diaminodiphenylmethane (11 g, 0.050 mol) dissolved in NMP (2,600 g) and reacted at 60 ° C. for 6 hours to contain a polyamic acid Got. 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 480 mPa · s.
Next, 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 reaction 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, and then concentrated to obtain about 2,500 g of a solution containing 15% by weight of polyimide (PI-19) having an imidization ratio of about 88%. Got. A small amount of this polyimide solution was taken, and γ-butyrolactone was added to measure the solution viscosity as a solution having a polyimide concentration of 10% by weight. The solution viscosity was 90 mPa · s.

Example 1
<Preparation of liquid crystal aligning agent>
An amount corresponding to 20 parts by weight of the solution containing polyimide (PI-2) obtained in Synthesis Example 3 in terms of polyimide (PI-2) and polyamic acid (PA-) obtained in Synthesis Example 12 1) The solution containing 1) is combined with an amount corresponding to 80 parts by weight in terms of polyamic acid (PA-1), and γ-butyrolactone, N-methyl-2-pyrrolidone and butyl cellosolve are combined with γ-butyrolactone: N In addition to the weight ratio of methyl-2-pyrrolidone: butyl cellosolve 71:17:12, an epoxy compound N, N, N ′, N′-tetraglycidyl-4, as an adhesion improver 2 parts by weight of 4′-diaminodiphenylmethane was added to prepare a solution having a solid concentration of 3.5% by weight. After sufficiently stirring this solution, a liquid crystal aligning agent was prepared by filtering using a filter having a pore size of 1 μm.
Evaluation was performed as follows using this liquid crystal aligning agent.
<Manufacture and evaluation of liquid crystal display elements>
[Manufacture of liquid crystal display elements]
(1) Application of liquid crystal aligning agent and formation of liquid crystal aligning film The liquid crystal aligning agent prepared above is rotated using a spinner on a transparent conductive film made of an ITO film provided on one surface of a glass substrate having a thickness of 1 mm. The film was applied under conditions of several 2,000 rpm and a rotation time of 20 seconds, pre-baked on an 80 ° C. hot plate for 1 minute, and then post-baked at 200 ° C. for 1 hour to form a film having a thickness of 0.08 μm. .
(2) Rubbing treatment Using a rubbing machine having a roll in which a rayon cloth is wound around the coating film, a rubbing treatment is performed under the conditions of a roll rotation speed of 400 rpm, a stage moving speed of 3 cm / sec, and a hair foot indentation length of 0.4 mm. Then, a liquid crystal alignment film was formed by imparting liquid crystal alignment ability to the coating film.
(3) Cleaning, drying, and bonding of alignment film coated substrate The substrate having the liquid crystal alignment film obtained above is ultrasonically cleaned in ultrapure water for 1 minute and then dried in a clean oven at 100 ° C. for 10 minutes. did. By repeating the same operation, two substrates (a pair) having a liquid crystal alignment film were manufactured.
(4) Liquid crystal injection step, adhesion of polarizing plate Next, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm was applied to each outer edge having the liquid crystal alignment film of the substrate having the pair of liquid crystal alignment films. After that, the liquid crystal alignment film surfaces were overlapped and pressed so as to face each other, and the adhesive was cured. Next, a nematic liquid crystal (MLC-6221, manufactured by Merck & Co., Inc.) having a positive dielectric anisotropy is filled between the liquid crystal inlet and the substrate, and then the liquid crystal inlet is filled with an acrylic photo-curing adhesive. The liquid crystal display element was manufactured by sealing and bonding a polarizing plate on both surfaces of the outer side of a board | substrate.

[Evaluation of liquid crystal display elements]
(1) Evaluation of liquid crystal alignment The liquid crystal display element manufactured above was observed using an optical microscope. At this time, the liquid crystal alignment was “good” when there was no light leakage, and the liquid crystal alignment was observed with light leakage. As a result, the liquid crystal orientation of this liquid crystal display element was “good”.
(2) Evaluation of heat resistance (heat stress test)
For the liquid crystal display device manufactured above, a voltage of 5 V was first applied 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. The numerical value at this time was defined as the initial voltage holding ratio (VHR _BF ). After the VHR _BF measurement, the liquid crystal display element was put in an oven at 100 ° C., and thermal stress was applied for 1,000 hours. Next, the liquid crystal display element was allowed to stand at room temperature and cooled to room temperature, and then the voltage holding ratio VHR _AF after application of thermal stress was measured. When the rate of change of the voltage holding ratio before and after the application of thermal stress was determined and the rate of change was less than 5%, the heat resistance was evaluated as “good”, and the rate of 5% or more was evaluated as “heat resistance”. The heat resistance of was “good”.
Examples 2 and 5
As the polymer, liquid crystal aligning agents were prepared in the same manner as in Example 1 except that the types shown in Table 1 were used in the amounts shown in Table 1, and liquid crystal display elements were produced and evaluated. The results are shown in Table 2.

Example 6
<Preparation of liquid crystal aligning agent>
An amount corresponding to 100 parts by weight in terms of the polyimide (PI-4) solution containing the polyimide (PI-4) obtained in Synthesis Example 5 was taken, and N-methyl-2-pyrrolidone and butyl cellosolve were added thereto. , N-methyl-2-pyrrolidone: butyl cellosolve in a weight ratio of 50:50, and N, N, N ′, N′-tetraglycidyl-4 which is an epoxy compound as an adhesion improver 2 parts by weight of 4′-diaminodiphenylmethane was added to prepare a solution having a solid concentration of 3.5% by weight. After sufficiently stirring this solution, a liquid crystal aligning agent was prepared by filtering using a filter having a pore size of 1 μm.
<Manufacture and evaluation of liquid crystal display elements>
An example except that a nematic liquid crystal (MLC-2038, manufactured by Merck & Co., Inc.) having a negative dielectric anisotropy was used as the liquid crystal, and (3) the rubbing treatment was not performed in the manufacturing process of the liquid crystal display element. A liquid crystal display device was produced in the same manner as in Example 1, and the liquid crystal orientation and heat resistance were evaluated. The results are shown in Table 2.
Examples 7 and 8
As the polymer, liquid crystal aligning agents were prepared in the same manner as in Example 6 except that the types shown in Table 1 were used in the amounts shown in Table 1, and liquid crystal display elements were produced and evaluated. The results are shown in Table 2.

Example 9 (Reference Example)
<Preparation of liquid crystal aligning agent>
An amount corresponding to 100 parts by weight in terms of the polyimide (PI-7) in the solution containing the polyimide (PI-7) obtained in Synthesis Example 8 was taken, and N was an epoxy compound as an adhesion improver. , N, N ′, N′-Tetraglycidyl-4,4′-diaminodiphenylmethane and a functional silane compound methyl 3- [2- (3-trimethoxysilylpropylamino) ethylamino] propionate 0.75 parts by weight was added, and γ-butyrolactone and butyl cellosolve were added so that the γ-butyrolactone: butyl cellosolve ratio was 80:20 by weight to obtain a solution having a solid concentration of 3.5% by weight. A liquid crystal aligning agent was prepared by filtering this solution using a filter having a pore diameter of 1 μm.
<Manufacture and evaluation of liquid crystal display elements>
A liquid crystal display device was produced in the same manner as in Example 1 except that nematic liquid crystal (MLC-2019, MLC-2019) having a positive dielectric anisotropy was used as the liquid crystal. The results are shown in Table 2.
Examples 10 and 11 (both are reference examples)
As the polymer, liquid crystal aligning agents were prepared in the same manner as in Example 9 except that the types shown in Table 1 were used in the amounts shown in Table 1, and liquid crystal display elements were produced and evaluated. The results are shown in Table 2.

Example 12
<Preparation of liquid crystal aligning agent>
An amount corresponding to 40 parts by weight of the solution containing the polyimide (PI-10) obtained in Synthesis Example 11 in terms of polyimide (PI-10) and the polyamic acid (PA-) obtained in Synthesis Example 15 4) The solution containing 4) is combined with an amount corresponding to 60 parts by weight in terms of polyamic acid (PA-4), γ-butyrolactone, N-methyl-2-pyrrolidone and butyl cellosolve are In addition to the weight ratio of methyl-2-pyrrolidone: butyl cellosolve of 40:40:20, N, N, N ′, N′-tetraglycidyl-4, which is an epoxy compound as an adhesion improver 10 parts by weight of 4′-diaminodiphenylmethane was added to prepare a solution having a solid concentration of 3.5 weight. After sufficiently stirring this solution, a liquid crystal aligning agent was prepared by filtering using a filter having a pore size of 1 μm.
Evaluation was performed as follows using this liquid crystal aligning agent.
<Manufacture and evaluation of liquid crystal display elements>
A liquid crystal display device was produced in the same manner as in Example 1 except that nematic liquid crystal (MLC-2019, MLC-2019) having a positive dielectric anisotropy was used as the liquid crystal. The results are shown in Table 2.

Comparative Examples 1-5
As the polymer, a liquid crystal aligning agent was prepared in the same manner as in Example 1 except that the types shown in Table 1 were used in the amounts shown in Table 1, and liquid crystal display elements were produced and evaluated. The results are shown in Table 2.
Comparative Examples 6-8
As the polymer, liquid crystal aligning agents were prepared in the same manner as in Example 6 except that the types listed in Table 1 were used in the amounts shown in Table 1, and liquid crystal display elements were produced and evaluated. The results are shown in Table 2.
Comparative Examples 9 and 10
As the polymer, liquid crystal aligning agents were prepared in the same manner as in Example 9 except that the types shown in Table 1 were used in the amounts shown in Table 1, and liquid crystal display elements were produced and evaluated. The results are shown in Table 2.
Comparative Example 11
As the polymer, liquid crystal aligning agents were prepared in the same manner as in Example 12 except that the types shown in Table 1 were used in the amounts shown in Table 1, and liquid crystal display elements were produced and evaluated. The results are shown in Table 2.

The abbreviations in the “type” column and solvent composition of the adhesion improver in Table 1 have the following meanings, respectively.
<Adhesion improver>
Epoxy compound GAPM: N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane Functional silane compound MSPP: Methyl 3- [2- (3-trimethoxysilylpropylamino) ethylamino] propionate < Solvent composition>
BL: γ-butyrolactone NMP: N-methyl-2-pyrrolidone BC: Butyl cellosolve The descriptions in the “Liquid Crystal Name” column in Table 2 have the following meanings.
6221: MLC-6221 (trade name, manufactured by Merck & Co., Inc.)
2038: MLC-2038 (trade name, manufactured by Merck & Co., Inc.)
2019: MLC-2019 (trade name, manufactured by Merck & Co., Inc.)

Claims (7)

Tetracarboxylic dianhydride;
The following formula (A)

And a compound having two amino groups and
The following formula (D-III)

(In the formula (D-III), R ⁹ represents —O—, —COO— ^* , —OCO— ^* , —NHCO— ^* , —CONH— ^* (in the above, the bond indicated by “*” is R ¹⁰ is bonded to R ¹⁰ ) or —CO—, and R ¹⁰ is a monovalent organic group or carbon having a skeleton or group selected from a steroid skeleton, a trifluoromethylphenyl group, a trifluoromethoxyphenyl group, and a fluorophenyl group An alkyl group having 6 to 30 carbon atoms , R ¹¹ is an alkyl group having 1 to 4 carbon atoms, and a3 is an integer of 0 to 3.)
Compound represented by
Containing diamine and
It characterized in that it contains at least one polymer a polyamic acid and the polyamic acid obtained by reacting selected from the group consisting of polyimide obtained by cyclodehydration of the liquid crystal alignment agent. The structure represented by the above formula (A) is represented by the following formulas (A-1) to (A-3).

(R ^a in the formula (A-1) is a halogen atom, a cyano group, an isocyano group, —OCN, —NCO, —SCN, —NCS or an azide group, n is an integer of 0 to 3, and “* "Indicates that each is a bond;
R ^b and R ^c in formulas (A-2) and (A-3) are each independently a hydrogen atom, a halogen atom, a cyano group, an isocyano group, —OCN, —NCO, —SCN, —NCS or And “*” indicates a bond. )
The liquid crystal aligning agent of Claim 1 which is at least 1 type of structure selected from the group which consists of a structure represented by each of these. Compounds having the structure represented by the above formula (A) and two amino groups are represented by the following formulas (A-1-1), (A-2-1) and (A-3-1).

(R ^a and n in the formula (A-1-1) have the same meanings as in the formula (A-1), and Y ^a is a single bond or an arylene group having 6 to 10 carbon atoms;
R ^b and R ^c in formulas (A-2-1) and (A-3-1) have the same meanings as in formula (A-2) or (A-3), respectively, and Y ^b and Y ^c is each independently a single bond or an arylene group having 6 to 10 carbon atoms. )
Of at least one selected from the group consisting of compounds represented by the liquid crystal alignment agent according to claim 2. R ⁹ in the above formula (D-III) is —O— or —COO— ^* (where the bond marked with “*” binds to R ¹⁰ ), and R ¹⁰ is a monovalent steroid skeleton. an organic group, the liquid crystal alignment agent according to claim 1. The diamine further contains at least one selected from the group consisting of p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether, and bis [4- (4-aminophenoxy) phenyl] sulfone. it is Dressings, liquid crystal alignment agent according to any one of claims 1 to 4. Tetracarboxylic dianhydride is 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 1,3,3a, 4,5,9b- Selected from the group consisting of hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione and pyromellitic dianhydride at least one is intended to include liquid crystal alignment agent according to any one of claims 1 to 5 that. Characterized by comprising a liquid crystal alignment film formed from the liquid crystal alignment agent according to any one of claims 1 to 6 the liquid crystal display device.