JP2010286666A - Liquid crystal aligning agent, liquid crystal alignment film and liquid crystal display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide: a liquid crystal-aligning agent which can provide a liquid crystal alignment film with excellent heat resistance and forms a coating film with high film thickness uniformity; and a liquid crystal display element whose display performance does not deteriorate even after long-term driving while permitting high-quality display. <P>SOLUTION: The liquid crystal aligning agent includes at least one polymer selected from a group which includes a polyamic acid obtained by making tetracarboxylic acid dianhydride react with diamine including a compound represented by a formula (A), and a polyimide made by subjecting the polyamic acid to dehydrating cyclization. The liquid crystal alignment film is formed from the liquid crystal aligning agent. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a liquid crystal aligning agent, a liquid crystal alignment film, and a liquid crystal display element. More specifically, a liquid crystal aligning agent that can provide a liquid crystal aligning film having excellent printability and excellent heat resistance, a liquid crystal aligning film formed from the liquid crystal aligning agent and excellent in heat resistance, and a high-quality display. The present invention relates to a liquid crystal display element that is capable of being driven for a long time, in which display deterioration due to thermal stress is suppressed.

Currently known liquid crystal display elements can be classified into the following modes based on the electrode structure and the physical properties of the liquid crystal molecules used.
First, a liquid crystal alignment film is formed on the surface of a substrate on which a transparent conductive film is provided to form a substrate for a liquid crystal display element. A TN having a so-called TN type (twisted nematic) liquid crystal cell in which the long axis of the liquid crystal molecules is continuously twisted by 90 ° from one substrate to the other substrate by forming layers into a sandwich cell. 2. Description of the Related Art An STN (Super Twisted Nematic) type liquid crystal display element (Patent Document 2) capable of realizing a higher duty ratio than a TN type liquid crystal display element (Patent Document 1) and a TN type liquid crystal display element is known. Further, a counter electrode arrangement similar to that of the TN type liquid crystal display element is adopted, but a nematic liquid crystal layer having a negative dielectric anisotropy is injected into the electrode gap to align the liquid crystal substantially perpendicularly to the substrate. A Vertical Alignment) type display element is known (Patent Document 3). This VA type display element has a high contrast and can produce a large area display element.
On the other hand, an IPS (In-Plane Switching) type liquid crystal display element in which the driving direction of the liquid crystal when an electric field is applied is only in the in-plane direction of the substrate by arranging the electrode pairs in a comb-like shape on the surface of one substrate (patented) Document 4), an FFS (Fringe Field Switching) type liquid crystal display element (Patent Document 5) in which the luminance is improved by changing the IPS type electrode structure and increasing the aperture ratio of the display element portion is known, Excellent viewing angle characteristics.
In addition to these, an OCB (Optical Compensated Bend) type liquid crystal display element (Patent Document 6) that has low viewing angle dependency and excellent high-speed response of a video screen has 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, and in particular, a liquid crystal alignment film made of polyamic acid or polyimide has heat resistance, mechanical strength, It has excellent affinity with liquid crystals and is used in many liquid crystal display elements (Patent Documents 1 to 4, 7 and 8).
The liquid crystal display elements having these liquid crystal alignment films are designed on the assumption that the service life exceeds 10 years when used for television applications, which is extraordinary compared to the applications of conventional liquid crystal display elements. Long drive is planned. At the same time, in order to increase the size of the liquid crystal display element and display with high definition, the coating film formed by the liquid crystal aligning agent is required to be uniform over a large area.
However, a liquid crystal display device having a conventionally known liquid crystal alignment film has a problem that when the liquid crystal display element is driven for a long time, the liquid crystal alignment film is thermally deteriorated due to applied thermal stress, resulting in a decrease in voltage holding ratio. There was a problem. In particular, polyimide is considered to have a trade-off relationship between good heat resistance and coating uniformity, and no material that satisfies these simultaneously has been known.

JP-A-4-153622 JP 60-107020 A Japanese Patent Laid-Open No. 11-258605 JP 56-91277 A JP 2008-216572 A JP 2009-48211A US Pat. No. 5,928,733 Japanese Patent Laid-Open No. 62-165628 International Publication No. 2007/071091 Pamphlet 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 aligning agent that can provide a liquid crystal aligning film excellent in heat resistance and has high film thickness uniformity. The purpose is to do.
Another object of the present invention is to provide a liquid crystal alignment film excellent in liquid crystal alignment and heat resistance.
It is still another object of the present invention to provide a liquid crystal display element that can display a high quality and does not deteriorate the display performance even when driven for a long time.
Further 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:
Tetracarboxylic dianhydride and the following formula (A)

It is achieved by a liquid crystal aligning agent containing at least one polymer selected from the group consisting of a polyamic acid obtained by reacting with a diamine containing a compound represented by formula (I) and a polyimide obtained by dehydrating and ring-closing the polyamic acid. The
The above objects and advantages of the present invention are, secondly,
Achieved by a liquid crystal alignment film formed from the above liquid crystal aligning agent,
This is achieved by a liquid crystal display device comprising the above liquid crystal alignment film.

  The liquid crystal aligning agent of the present invention can form a uniform coating film, and the liquid crystal aligning film of the present invention formed from the liquid crystal aligning agent of the present invention has a liquid crystal aligning property even when a long-term heat stress is applied. There is no deterioration. The liquid crystal display element of the present invention having such a liquid crystal alignment film of the present invention can display a high quality, and does not deteriorate the display performance even when driven for a long period of time. It can be suitably used for display devices such as portable games, word processors, notebook computers, car navigation systems, camcorders, personal digital assistants, digital cameras, 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 comprises a polyamic acid obtained by reacting a tetracarboxylic dianhydride and a diamine containing the compound represented by the above formula (A), and a polyimide obtained by dehydrating and ring-closing the polyamic acid. At least one polymer selected from the group consisting of:
<Polyamic acid>
The polyamic acid in the present invention can be obtained by reacting a tetracarboxylic dianhydride with a diamine containing a compound represented by the above formula (A).

[Tetracarboxylic dianhydride]
Examples of the tetracarboxylic dianhydride used for the synthesis of the polyamic acid include butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1 , 2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dichloro-1,2,3,4 -Cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride Anhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3 ′, 4,4′-dicyclohexyltetracarboxylic dianhydride, 2,3,5-tricarboxy Pentylacetic dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl ) -Naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5-methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) ) -Naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-Hexahydro-5-ethyl-5- (tetrahydro-2,5-dioxo-3- Furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-7-methyl-5- (tetrahydro-2,5-dioxo-3 -Furanyl) -naphtho [1,2-c] -furan 1,3-dione, 1,3,3a, 4,5,9b-hexahydro-7-ethyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c]- Furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -Furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8-ethyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c ] -Furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5,8-dimethyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1, 2-c] -furan-1,3-dione, bicyclo [2.2.2] -o To-7-ene-2,3,5,6-tetracarboxylic dianhydride, 3-oxabicyclo [3.2.1] octane-2,4-dione-6-spiro-3 ′-(tetrahydrofuran- 2 ', 5'-dione), 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 3,5,6-tricarboxy 2-carboxymethylnorbornane-2: 3,5: 6-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^2,6 ] undecane-3,5,8,10-tetraone The following formulas (TI) and (T-II)

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

An aromatic tetracarboxylic dianhydride such as a compound represented by each of the above can be exemplified. The benzene ring of the aromatic tetracarboxylic dianhydride may be substituted with one or two or more alkyl groups having 1 to 4 carbon atoms (preferably a methyl group).
These tetracarboxylic dianhydrides can be used singly or in combination of two or more.
As tetracarboxylic dianhydride used for the synthesis of polyamic acid in the present invention, among the above, butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3 -Dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3 3a, 4,5,9b-Hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3 3a, , 5,9b-Hexahydro-5,8-dimethyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, bicyclo [2,2 , 2] -Oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 3-oxabicyclo [3.2.1] octane-2,4-dione-6-spiro-3 ′ -(Tetrahydrofuran-2 ', 5'-dione), 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 3,5 6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^2,6 ] undecane-3,5,8 , 10-tetraone, pyromellitic dianhydride, 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 3,3', 4,4'-biphenylsulfonetetracarboxylic dianhydride, 2,2 ', 3,3'-biphenyltetracarboxylic dianhydride Product, 1,4,5,8-naphthalenetetracarboxylic dianhydride, the following formulas (T-5) to (T-7) among the compounds represented by the above formula (TI)

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

The liquid crystal alignment film to be formed exhibits good liquid crystal alignment properties when it contains at least one selected from the group consisting of the compounds represented by (hereinafter referred to as “specific tetracarboxylic dianhydride”). From the viewpoint of doing so, it is preferable.
More preferably, the specific tetracarboxylic dianhydride is 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 1,3,3a, 4, 5,9b-Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b- Hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 3-oxabicyclo [3.2.1] octane -2,4-dione-6-spiro-3 '-(tetrahydrofuran-2', 5'-dione), 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene- 1,2-dicarbo Acid anhydride, 3,5,6-tricarboxy-2-carboxymethyl norbornane -2: 3,5: 6-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^{2, 6} ] At least one selected from the group consisting of undecane-3,5,8,10-tetraone, pyromellitic dianhydride and the compound represented by the above formula (T-5), particularly preferably 2, 3,5-tricarboxycyclopentyl acetic acid dianhydride.
The tetracarboxylic dianhydride used for the synthesis of the polyamic acid in the present invention preferably contains 50 mol% or more of the specific tetracarboxylic dianhydride as described above with respect to the total tetracarboxylic dianhydride. , 60 mol% is more preferable, and 80 mol% or more is particularly preferable.
As the tetracarboxylic dianhydride used for the synthesis of the polyamic acid in the present invention, it is most preferable to use only the specific tetracarboxylic dianhydride as described above.

[Diamine]
The diamine used for the synthesis of the polyamic acid in the present invention includes a compound represented by the above formula (A). Preferable specific examples of the compound represented by the formula (A) include 4,4′-diamino-1,1′-biphenyl-2,2′-dicarboxylic acid and the like. Such a compound represented by the above formula (A) can be synthesized by, for example, a method described in Patent Document 9 (International Publication No. 2007/071091 pamphlet).
As the diamine used for synthesizing the polyamic acid in the present invention, only the compound represented by the above formula (A) may be used alone, and the compound represented by the above formula (A) and other diamines may be used. May be used in combination.
Examples of other diamines that can be used here include p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylethane, 4,4′-diaminodiphenyl sulfide, 4,4′-diaminodiphenyl sulfone, 3,3′-dimethyl-4,4′-diaminobiphenyl, 4,4′-diaminobenzanilide, 4,4′-diaminodiphenyl ether, 1,5-diaminonaphthalene, 2, 2'-dimethyl-4,4'-diaminobiphenyl, 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'- Aminobenzophenone, 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, bis [4- (4-aminophenoxy) phenyl] sulfone, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4- Aminophenoxy) biphenyl, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 9,9-bis (4-aminophenyl) -10-hydroanthracene, 2, 7-diaminofluorene, 9,9-dimethyl-2,7-diaminofluorene, 9,9-bis (4-aminophenyl) fluorene Len, bis (4-amino-2-chlorophenyl) methane, 2,2 ', 5,5'-tetrachloro-4,4'-diaminobiphenyl, 2,2'-dichloro-4,4'-diamino-5 , 5′-dimethoxybiphenyl, 3,3′-dimethoxy-4,4′-diaminobiphenyl, 4,4 ′-(p-phenylenediisopropylidene) bisaniline, 4,4 ′-(m-phenylenediisopropylidene) Bisaniline, 2,2′-bis [4- (4-amino-2-trifluoromethylphenoxy) phenyl] hexafluoropropane, 4,4′-diamino-3,3′-bis (trifluoromethyl) biphenyl, 4 , 4′-Diamino-2,2′-bis (trifluoromethyl) biphenyl, 4,4′-bis [(4-amino-2-trifluoromethyl) phenoxy] -octafluorobiphe Le, the following formula (D-1) ~ (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.)
An aromatic diamine such as a compound represented by each of the following:
1,1-metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, 1,4-diaminocyclohexane, isophoronediamine, Tetrahydrodicyclopentadienylenediamine, hexahydro-4,7-methanoindanylene methylenediamine, tricyclo [6.2.1.0 ^2,7 ] -undecylenediethylenediamine, 4,4′-methylenebis (cyclohexylamine) ), 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane and other aliphatic and alicyclic diamines;
2,3-diaminopyridine, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 5,6-diamino-2,3-dicyanopyrazine, 5,6-diamino-2,4 -Dihydroxypyrimidine, 2,4-diamino-6-dimethylamino-1,3,5-triazine, 1,4-bis (3-aminopropyl) piperazine, 2,4-diamino-6-isopropoxy-1,3 , 5-triazine, 2,4-diamino-6-methoxy-1,3,5-triazine, 2,4-diamino-6-phenyl-1,3,5-triazine, 2,4-diamino-6-methyl -S-triazine, 2,4-diamino-1,3,5-triazine, 4,6-diamino-2-vinyl-s-triazine, 2,4-diamino-5-phenylthiazole, 2,6- Aminopurine, 5,6-diamino-1,3-dimethyluracil, 3,5-diamino-1,2,4-triazole, 3,8-diamino-6-phenylphenanthridine, 1,4-diaminopiperazine, 3,6-diaminoacridine, N, N′-bis (4-aminophenyl) phenylamine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, N-ethyl-3,6-diaminocarbazole N-phenyl-3,6-diaminocarbazole, N, N′-bis (4-aminophenyl) -benzidine, N, N′-bis (4-aminophenyl) -N, N′-dimethyl-benzidine, and The following formulas (D-I) and (D-II)

(In the formula (DI), R ⁵ is a monovalent organic group having a ring structure containing a nitrogen atom selected from the group consisting of pyridine, pyrimidine, triazine, piperidine and piperazine, and X ¹ is a divalent group. An organic group;
In the formula (D-II), R ⁶ is a divalent organic group having a ring structure containing a nitrogen atom selected from the group consisting of pyridine, pyrimidine, triazine, piperidine and piperazine, and X ² is 2 And a plurality of X ² may be the same or different. )
A diamine having two primary amino groups in the molecule and a nitrogen atom other than the primary amino group, such as a compound represented by each of:
The following formula (D-III)

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

(In the formula (D-IV), R ⁹ is a hydrocarbon group having 1 to 12 carbon atoms, and a plurality of R ⁹ 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 diaminoorganosiloxanes such as compounds represented by the formula: The aromatic diamine, a diamine ring having two primary amino groups in the molecule and a nitrogen atom other than the primary amino group, and a mono-substituted phenylenediamine have one or two or more carbon atoms of 1 to 4 May be substituted with an alkyl group (preferably a methyl group). In addition, the steroid skeleton in the above formula (D-III) refers to a skeleton composed of a cyclopentano-perhydrophenanthrene nucleus or a skeleton in which one or more of the carbon-carbon bonds are double bonds.
These diamines can be used alone or in combination of two or more.

  Other diamines used for synthesizing the polyamic acid in the present invention include p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl sulfide, and 1,5-diaminonaphthalene among the above. 2,2′-dimethyl-4,4′-diaminobiphenyl, 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl, 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] hexafluoro Propane, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4 ′-(p-phen Range isopropylidene) bisaniline, 4,4 ′-(m-phenylenediisopropylidene) bisaniline, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, 1, 4-diaminocyclohexane, 4,4′-methylenebis (cyclohexylamine), 1,3-bis (aminomethyl) cyclohexane, compounds represented by the above formulas (D-1) to (D-5), 2, 6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminoacridine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, N-ethyl-3, 6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N, N′-bis (4-amino Phenyl) - benzidine, N, N'-bis (4-aminophenyl) -N, N'-dimethyl-benzidine, formula of the compound represented by the above formula (D-I) (D-6)

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

Of the compounds represented by formula (D-III), dodecanoxy-2,4-diaminobenzene, pentadecanoxy-2,4-diaminobenzene, hexadecanoxy-2,4-diaminobenzene, octadecanoxy- 2,4-diaminobenzene, dodecanoxy-2,5-diaminobenzene, pentadecanoxy-2,5-diaminobenzene, hexadecanoxy-2,5-diaminobenzene, octadecanoxy-2,5-diaminobenzene, the following formula (D-8) ~ (D-15)

And at least one selected from the group consisting of 1,3-bis (3-aminopropyl) -tetramethyldisiloxane among the compounds represented by the formula (D-IV) Hereinafter, it is preferable to use “other specific diamine”.
The diamine used for the synthesis of the polyamic acid in the present invention preferably contains 0.1 mol% or more of the compound represented by the above formula (A) with respect to the total diamine, and contains 1 to 40 mol%. More preferably, it is particularly preferable to contain 5 to 30 mol%.
It is preferable that the diamine used for the synthesis | combination of the polyamic acid in this invention contains the above other specific diamine other than the compound represented by the said Formula (A). In this case, the use ratio of the other specific diamine is preferably 20 mol% or more, more preferably 40 to 99.9 mol%, particularly 70 to 99 mol%, based on the total diamine. It is preferable.
It is preferable that the diamine used for the synthesis | combination of the polyamic acid in this invention consists only of a compound represented by the said Formula (A), and another specific diamine.

[Synthesis of polyamic acid]
The polyamic acid in the present invention can be obtained by reacting a tetracarboxylic dianhydride with a diamine containing a compound represented by the above formula (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 the ratio which becomes 0.3-1.2 equivalent.
The polyamic acid synthesis reaction is preferably performed in an organic solvent, preferably at a temperature of −20 ° C. to 150 ° C., more preferably 0 to 100 ° C., and preferably 0.1 to 24 hours, more preferably 0.00. It takes 5 to 12 hours.
Examples of the organic solvent that can be used in the synthesis of the polyamic acid include an aprotic polar solvent, phenol and derivatives thereof, alcohol, ketone, ester, ether, halogenated hydrocarbon, hydrocarbon and the like.

Examples of the aprotic polar solvent include N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide and the like. ;
Examples of the phenol derivative include m-cresol, xylenol, halogenated phenol and the like;
Examples of the alcohol include methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, and ethylene glycol monomethyl ether;
Examples of the ketone include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone;
Examples of the ester include ethyl lactate, butyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, diethyl oxalate, and diethyl malonate;
Examples of the ether include 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, etc .;
Examples of the halogenated hydrocarbon include dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene and the like;
Examples of the hydrocarbon include hexane, heptane, octane, benzene, toluene, xylene, isoamylpropionate, isoamylisobutyrate, and diisopentyl ether.

Among these organic solvents, one or more selected from the group consisting of an aprotic polar solvent and phenol and derivatives thereof (first group organic solvent), or one selected from the first group of organic solvents It is preferable to use a mixture of the above and one or more selected from the group consisting of alcohols, ketones, esters, ethers, halogenated hydrocarbons and hydrocarbons (second group organic solvent). In the latter case, the use ratio of the second group of organic solvents is preferably 50% by weight or less, more preferably 40% by weight or less, with respect to the total of the first group of organic solvents and the second group of organic solvents. Furthermore, it is preferable that it is 30 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 solvent in the reaction solution under reduced pressure using an evaporator. It can be carried out. 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 evaporating under reduced pressure with an evaporator once or several times.

<Polyimide>
The polyimide in the present invention can be obtained by dehydrating and ring-closing the polyamic acid as described above to imidize.
Examples of the tetracarboxylic dianhydride used for the synthesis of the polyimide include the same compounds as the tetracarboxylic dianhydride used for the synthesis of the polyamic acid described above. The kind of preferable tetracarboxylic dianhydride and its preferable usage rate are the same as in the case of polyamic acid.
Examples of the diamine used for synthesizing the polyimide in the present invention include the same diamine as the diamine used for the synthesis of the polyamic acid. That is, the diamine used for the synthesis | combination of the polyimide contained in the liquid crystal aligning agent of this invention contains the compound represented by the said Formula (A), and uses only the compound represented by the said Formula (A). Alternatively, the compound represented by the formula (A) and the other diamine may be used in combination. The types of other preferred diamines and the preferred use ratio of each diamine are the same as in the case of polyamic acid.
The polyimide in the present invention may be a completely imidized product obtained by dehydrating and cyclizing all of the amic acid structure possessed by the polyamic acid as a raw material, dehydrating and cyclizing only a part of the amic acid structure, It may be a partially imidized product in which an imide ring structure coexists. The polyimide in the present invention preferably has an imidization rate of 30% or more, and more preferably 40% or more. This imidation ratio represents the ratio of the number of imide ring structures to the total of the number of polyimide amic acid structures and the number of imide ring structures in percentage. At this time, a part of the imide ring may be an isoimide ring.

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. 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. The reaction time is preferably 1.0 to 24 hours, more preferably 1.0 to 12 hours.
On the other hand, in the method (ii) of adding a dehydrating agent and a dehydrating ring-closing catalyst to the polyamic acid solution, 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 desired imidation rate, 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. The amount of the dehydration ring-closing catalyst used is preferably 0.01 to 10 mol with respect to 1 mol of the dehydrating agent 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 1.0 to 120 hours, more preferably 2.0 to 30 hours.

  The polyimide obtained in the above method (i) may be used for the preparation of the liquid crystal aligning agent as it is, or may be used for the preparation of the liquid crystal aligning agent after purifying the obtained polyimide. On the other hand, in the method (ii), a reaction solution containing 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 in the present invention may each be a terminal-modified polymer having a controlled molecular weight. 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 anhydride etc .;
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 and the like;
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 or polyimide obtained as described above preferably has a solution viscosity of 20 to 800 mPa · s, and has a solution viscosity of 30 to 500 mPa · s when a 10% by weight solution is obtained. It is more preferable to have it.
The solution viscosity (mPa · s) of the above polymer is E for a polymer solution having a concentration of 10% by weight prepared using a good solvent for the polymer (for example, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.). It is a value measured at 25 ° C. using a mold rotational viscometer.
<Other ingredients>
The liquid crystal alignment film of the present invention contains, as an essential component, at least one selected from the group consisting of the polyamic acid as described above and a polyimide obtained by imidizing the polyamic acid, but contains other components as necessary. May be. 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 includes a polyamic acid obtained by reacting a tetracarboxylic dianhydride and a diamine containing the compound represented by the above formula (A), and a polymer other than a polyimide obtained by dehydrating and ring-closing the polyamic acid. A polyamic acid obtained by reacting, for example, tetracarboxylic dianhydride with a diamine not containing the compound represented by the above formula (A) (hereinafter referred to as “other polyamic acid”), the polyamic acid. Polyimide obtained by dehydrating and cyclizing acid (hereinafter referred to as “other polyimide”), polyamic acid ester, polyester, polyamide, polysiloxane, cellulose derivative, polyacetal, polystyrene derivative, poly (styrene-phenylmaleimide) derivative, poly ( And (meth) acrylate. Of these, other polyamic acids or other polyimides are preferred, and other polyamic acids are more preferred.
Other polymers may be used in the total amount of the polymer (the polyamic acid obtained by reacting the tetracarboxylic dianhydride with the diamine containing the compound represented by the formula (A)) and the polyamic acid. Is the total of polyimide and other polymers formed by dehydration and ring closure, the same shall apply hereinafter)), preferably 50% by weight or less, more preferably 0.1 to 40% by weight, and further 10 to 30%. It is preferable that it is weight%.
The polymer contained in the liquid crystal aligning agent of the present invention is obtained by dehydrating and ring-closing polyamic acid obtained by reacting tetracarboxylic dianhydride with a diamine containing a compound represented by the above formula (A). Using only polyimide or a polyamic acid obtained by reacting a tetracarboxylic dianhydride and a diamine containing a compound represented by the above formula (A) and dehydrating and ring-closing a polyimide and other polyamic acids It is preferable to use together. In the latter case, the average imidation ratio of both polymers is preferably 10 to 98%, more preferably 15 to 60%. This average imidation ratio is the number of polyimide imide ring structures (PI-I) and the number of amic acid structures (PI-A) and the number of amic acid structures of polyamic acid (PA-A). ) From the following formula (1)

The value calculated by.
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, trimethylolpropane triglycidyl 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′-diaminodiphenyl Tan, N, N-diglycidyl - benzylamine, N, N-diglycidyl - aminomethyl cyclohexane, N, N-diglycidyl - cyclohexyl amine may be mentioned as preferred.
The compounding ratio of these epoxy compounds 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 amount of the 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-trimethoxysilyl-3,6-diazanonyl acetate, 9- Triethoxysilyl-3,6-diazanonyl acetate, methyl 9-trimethoxysilyl-3,6-diazananoate, methyl 9-triethoxysilyl-3,6-diazananoate, N-benzyl-3-aminopropyltri Methoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, glycidoxymethyltrimethoxysilane, glycidoxy Methyltriethoxysilane, 2-glycidoxyethyltrimeth Shishiran, 2-glycidoxyethyl triethoxysilane, 3-glycidoxypropyl trimethoxysilane, 3-glycidoxypropyl triethoxysilane, and the like.
The blending ratio of these functional silane compounds is preferably 2 parts by weight or less, more preferably 0.02 to 0.2 parts by weight with respect to 100 parts by weight of the total amount of the polymer.

In the liquid crystal aligning agent of the present invention, at least one polymer selected from the group consisting of the above polyamic acid and polyimide, and other additives optionally blended as necessary, are preferably in an organic solvent. Dissolved and contained in the composition.
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, diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, diisopentyl ether, ethylene carbonate, propylene carbonate, etc. Can be mentioned. These can be used alone or in combination of two or more.

The solid content concentration in the liquid crystal aligning agent of the present invention (the ratio of the total weight of components other than the solvent of the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) 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 wt%. 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 solid content concentration range varies depending on the method used when applying the liquid crystal aligning agent to the substrate. For example, when the spinner 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 10-50 degreeC, More preferably, it is 20-30 degreeC.

<Liquid crystal display element>
The liquid crystal display element of the present invention comprises a liquid crystal alignment film formed from the liquid crystal aligning agent of the present invention as described above.
The liquid crystal display element of the present invention can be produced, for example, by the following steps (1) to (3). In step (1), the substrate to be used differs 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) When manufacturing a TN type, STN type, or VA type liquid crystal display element, a pair of two substrates provided with a patterned transparent conductive film is used as a pair on each transparent conductive film formation surface. The liquid crystal aligning agent of the present invention is preferably applied by an offset printing method, a spin coating method or an ink jet printing method, respectively, and then each coated surface is heated 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 the transparent conductive film provided on one surface of the 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 a transparent conductive film The method using can be used. 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 application of the liquid crystal aligning agent, preheating (pre-baking) is preferably performed for the purpose of preventing dripping of the applied aligning agent. The pre-bake 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, more preferably 0.5 to 5 minutes. Then, a baking (post-baking) process is implemented for the purpose of removing a solvent completely, and heat imidizing a polyamic acid as needed. The firing (post-bake) temperature is preferably 80 to 300 ° C, more preferably 120 to 250 ° C, and the post-bake time is preferably 5 to 200 minutes, more preferably 10 to 100 minutes. Thus, the film thickness of the formed film 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 On one surface, the liquid crystal aligning agent of the present invention is preferably applied by an offset printing method, a spin coating method, or an ink jet printing method, and then each coated surface is heated to form a coating film.
The material used for the substrate and the transparent conductive film, the patterning method for the transparent conductive film, the pretreatment of the substrate, and the heating method after applying the liquid crystal aligning agent are the same as in (1-1) above.
The preferable film thickness of the coating film to be formed is the same as (1-1) above.

(2) When the liquid crystal display element manufactured by the method of the present invention is a VA type liquid crystal display element, the coating film formed as described above can be used as it is as a liquid crystal alignment film. If desired, it may be used after the following rubbing treatment.
On the other hand, when manufacturing a liquid crystal display element other than the VA type, a rubbing treatment is performed on the coating film formed as described above to obtain a liquid crystal alignment film.
The rubbing treatment can be performed by rubbing the coating film surface formed as described above with a roll wound with a cloth made of fibers such as nylon, rayon, and cotton in a certain direction. Thereby, the orientation ability of liquid crystal molecules is imparted to the coating film to form a liquid crystal orientation film.
Further, for the liquid crystal alignment film formed as described above, for example, a liquid crystal as shown in Patent Document 10 (JP-A-6-222366) or Patent Document 11 (JP-A-6-281937). A process of changing the pretilt angle of a partial region of the liquid crystal alignment film by irradiating a part of the alignment film with ultraviolet rays, or a liquid crystal alignment as disclosed in Patent Document 12 (Japanese Patent Laid-Open No. 5-107544) A resist film is formed on a part of the film surface, then the 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 in each region. It is possible to improve the visual field characteristics of the liquid crystal display element obtained by the above.

(3) A liquid crystal cell is manufactured by preparing two substrates on which a liquid crystal alignment film is formed as described above, and disposing a liquid crystal between the two substrates opposed to each other. Here, when the rubbing process is performed on the coating film, the two substrates are disposed to face each other so that the rubbing directions in the respective coating films are at a predetermined angle, for example, orthogonal or antiparallel.
In order to manufacture a liquid crystal cell, the following two methods are mentioned, for example.
The first method is a conventionally known method. First, two substrates are arranged to face each other through a gap (cell gap) so that the respective liquid crystal alignment films are opposed to each other, and the peripheral portions of the two substrates are bonded using a sealant, and the substrate surface and the sealant are bonded. A liquid crystal cell can be manufactured by injecting and filling liquid crystal into the cell gap partitioned by the step, and then sealing the injection hole.
The second method is a method called an ODF (One Drop Fill) method. For example, an ultraviolet light curable sealing material is applied to a predetermined location on one of the two substrates on which the liquid crystal alignment film is formed, and liquid crystal is dropped on the liquid crystal alignment film surface. The other substrate is bonded so as to face each other, and then the entire surface of the substrate is irradiated with ultraviolet light to cure the sealant, whereby a liquid crystal cell can be manufactured.
Regardless of which method is used, the liquid crystal cell produced as described above is further heated to a temperature at which the liquid crystal used takes an isotropic phase, and then gradually cooled to room temperature, so that the flow alignment during liquid crystal injection is achieved. It is desirable to remove.
And the liquid crystal display element of this invention can be obtained by bonding a polarizing plate on the outer surface of a liquid crystal cell.

Here, as the sealing agent, for example, an epoxy resin containing a curing agent and aluminum oxide spheres as a spacer can be used.
As the liquid crystal, for example, nematic liquid crystal, smectic liquid crystal, or the like can be used, and among these, nematic liquid crystal is preferable. In the case of a VA liquid crystal cell, a nematic liquid crystal having negative dielectric anisotropy is preferable. For example, dicyanobenzene liquid crystal, pyridazine liquid crystal, Schiff base liquid crystal, azoxy liquid crystal, biphenyl liquid crystal, and phenylcyclohexane liquid crystal are used. It is done. In the case of a TN type liquid crystal cell or an STN type liquid crystal cell, a nematic type liquid crystal having positive dielectric anisotropy is preferable. For example, biphenyl type liquid crystal, phenyl cyclohexane type liquid crystal, ester type liquid crystal, terphenyl type liquid crystal, biphenyl cyclohexane type A liquid crystal, a pyrimidine liquid crystal, a dioxane liquid crystal, a bicyclooctane liquid crystal, a cubane liquid crystal, or the like is used. Examples of these liquid crystals include cholesteric liquid crystals such as cholestyl chloride, cholesteryl nonate, and cholesteryl carbonate; chiral agents such as those sold under the trade names C-15 and CB-15 (Merck); p-decyloxybenzylidene Ferroelectric liquid crystals such as -p-amino-2-methylbutyl cinnamate may be further added and used.
As a polarizing plate bonded to the outer surface of the liquid crystal cell, a polarizing film or an H film in which a polarizing film called an “H film” that absorbs iodine while stretching and aligning polyvinyl alcohol is sandwiched between protective films of cellulose acetate The polarizing plate which consists of itself can be mentioned.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. The 4,4′-diamino-1,1′-biphenyl-2,2′-dicarboxylic acid used in the following synthesis examples is in accordance with the method described in Patent Document 13 (International Publication No. 2007/071091 pamphlet). The synthesized one was used.
The solution viscosity of each polymer and the imidation ratio of polyimide in the following synthesis examples were measured by the following methods, respectively.
[Solution viscosity of polymer]
The solution viscosity (mPa · s) of the polymer was 25 ° C. using an E-type rotational viscometer for the polymer solution adjusted to a predetermined polymer concentration in each synthesis example using the solvent described in each synthesis example. Measured with
[Imidation rate of polyimide]
A small amount of the polyimide-containing solution obtained in each synthesis example was collected and poured into pure water, and the resulting precipitate was sufficiently dried at room temperature under reduced pressure, then dissolved in deuterated dimethyl sulfoxide, and tetramethylsilane. From the ¹ H-NMR spectrum measured at room temperature using as a reference substance, the following formula (2)
Imidation rate (%) = (1-A ¹ / A ² × α) × 100 (2)
(In Formula (2), A ¹ is a peak area derived from protons of NH groups 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). (This is the ratio of the number of other protons to one proton of the NH group.)
By calculation.

<Polyimide synthesis example>
Synthesis Example PI-1 (Polyimide Synthesis Example 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 155 g (0.50 mol), p-phenylenediamine 60 g (0.57 mol) as diamine, 4, 80 g (0.30 mol) of 4′-diamino-1,1′-biphenyl-2,2′-dicarboxylic acid, 25 g (0.10 mol) of 1,3-bis (3-aminopropyl) tetramethyldisiloxane and 3,6-bis (4-aminobenzoyloxy) cholestane 13 g (0.020 mol) and aniline 2.7 g (0.030 mol) as N-methyl-2 It was dissolved in pyrrolidone 960 g, to obtain a solution containing a polyamic acid for 6 hours at 60 ° C.. A small amount of the obtained polyamic acid solution was taken, and N-methyl-2-pyrrolidone was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 55 mPa · s.
Next, 2,700 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 400 g of pyridine and 410 g of acetic anhydride were added, and dehydration ring closure was performed at 110 ° C. for 4 hours. After the dehydration ring closure reaction, the solvent in the system was replaced with new γ-butyrolactone (the pyridine and acetic anhydride used in the dehydration ring closure reaction were removed from the system in this operation. The same applies hereinafter). About 2,900 g of a solution containing about 15% by weight of polyimide (PI-1) having a rate of about 95% was obtained. A small amount of the obtained polyimide solution was collected, and γ-butyrolactone was added thereto, and the solution viscosity measured as a solution having a polyimide concentration of 10% by weight was 65 mPa · s.

Synthesis Example PI-2 (Polyimide Synthesis Example 2)
110 g (0.50 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride and 26 g (0.25 mol) of p-phenylenediamine as diamine, 4,4′-diamino-1 , 1′-biphenyl-2,2′-dicarboxylic acid 40 g (0.15 mol) and 3 (3,5-diaminobenzoyloxy) cholestane 51 g (0.10 mol) were dissolved in N-methyl-2-pyrrolidone 830 g. Then, the 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 taken, and N-methyl-2-pyrrolidone was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 50 mPa · s.
Next, 1,900 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 40 g of pyridine and 51 g of acetic anhydride were added, and dehydration ring closure was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with new N-methyl-2-pyrrolidone to obtain a solution containing about 15% by weight of polyimide (PI-2) having an imidization ratio of about 50%. , 340 g was obtained. A small amount of the obtained polyimide solution was taken, N-methyl-2-pyrrolidone was added, and the solution viscosity measured as a solution having a polyimide concentration of 10% by weight was 41 mPa · s.

Synthesis Example PI-3 (Polyimide Synthesis Example 3)
77 g (0.34 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as tetracarboxylic acid anhydride and 26 g (0.24 mol) of p-phenylenediamine and 4,4′-diamino-1,4 as diamine 28 g (0.10 mol) of 1'-biphenyl-2,2'-dicarboxylic acid is dissolved in 1,260 g of N-methyl-2-pyrrolidone and reacted at room temperature for 6 hours to obtain a solution containing polyamic acid. It was. A small amount of the obtained polyamic acid solution was collected and concentrated under reduced pressure, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 71 mPa · s.
Next, 600 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 190 g of pyridine and 147 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 further concentrated to obtain 800 g of a solution containing 20% by weight of polyimide (PI-3) having an imidization ratio of about 85%. . A small amount of the obtained polyimide solution was taken, and γ-butyrolactone was added thereto, and the solution viscosity measured as a solution having a polyimide concentration of 6.0% by weight was 19 mPa · s.

Synthesis Example PI-4 (Polyimide Synthesis Example 4)
224 g (1.0 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic anhydride and 54 g (0.5 mol) of p-phenylenediamine as diamine, 4,4′-diamino-1, 1'-biphenyl-2,2'-dicarboxylic acid 81 g (0.30 mol), 4,4'-diaminodiphenylmethane 19 g (0.1 mol) and 2,2'-trifluoromethyl-4,4'-diamino 32 g (0.1 mol) of biphenyl was dissolved in 2,700 g of N-methyl-2-pyrrolidone and reacted at room temperature for 6 hours to obtain a solution containing polyamic acid. A small amount of the obtained polyamic acid solution was taken, N-methyl-2-pyrrolidone was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 74 mPa · s.
Next, 2,000 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 150 g of pyridine and 200 g of acetic anhydride were added, and a 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 further concentrated to obtain 2,650 g of a solution containing 15% by weight of polyimide (PI-4) having an imidization ratio of about 85%. Obtained. A small amount of this polyimide solution was sampled, and γ-butyrolactone was added thereto, and the solution viscosity measured as a solution having a polyimide concentration of 6.0% by weight was 18 mPa · s.

<Synthesis examples of other polymers>
[Synthesis example of other polyimides]
Synthesis example pi-1 (Synthesis example 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 155 g (0.50 mol), p-phenylenediamine 92 g (0.87 mol) as diamine, bisamino 25 g (0.10 mol) of propyltetramethyldisiloxane and 13 g (0.02 mol) of 3,6-bis (4-aminobenzoyloxy) cholestane and 2.7 g (0.030 mol) of aniline as monoamine were added to N-methyl. 2-Pyrrolidone was dissolved in 960 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 taken, N-methyl-2-pyrrolidone was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 59 mPa · s.
Next, 2,700 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 396 g of pyridine and 409 g of acetic anhydride were added, and dehydration ring closure was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with new γ-butyrolactone and further concentrated to obtain about 2,520 g of a solution containing 15% by weight of polyimide (pi-1) having an imidation ratio of about 95%. Got. A small amount of this polyimide solution was sampled, and γ-butyrolactone was added thereto, and the solution viscosity measured as a solution having a polyimide concentration of 6.0% by weight was 18 mPa · s.
Synthesis example pi-2 (Synthesis example 2 of other polyimide)
110 g (0.50 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride and 42 g (0.40 mol) of p-phenylenediamine and 3 (3,5-diaminobenzoyl) as diamine Oxy) cholestane 51 g (0.10 mol) was dissolved in N-methyl-2-pyrrolidone 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 taken, and N-methyl-2-pyrrolidone was added to measure the solution viscosity as a solution having a polyamic acid concentration of 10% by weight. The solution viscosity was 80 mPa · s.
Next, 1,900 g of N-methyl-2-pyrrolidone 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 γ-butyrolactone and further concentrated to obtain 1,300 g of a solution containing 15% by weight of polyimide (pi-2) having an imidation ratio of about 92%. Obtained. 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 6% by weight. The solution viscosity was 30 mPa · s.

Synthesis example pi-3 (Synthesis example 3 of other polyimide)
77 g (0.34 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic acid anhydride and 37 g (0.34 mol) of p-phenylenediamine as diamine were added to N-methyl-2-pyrrolidone 1, The solution was dissolved in 000 g and reacted at room temperature for 6 hours to obtain a solution containing 10% by weight of polyamic acid. The solution viscosity of the obtained polyamic acid solution was 75 mPa · s.
Next, 490 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 135 g of pyridine and 110 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 further concentrated to obtain 510 g of a solution containing 20% by weight of polyimide (pi-3) having an imidization ratio of about 85%. . 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 6.0% by weight was 21 mPa · s.
Synthesis example pi-4 (Synthesis example 4 of other polyimides)
224 g (1.0 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as tetracarboxylic acid anhydride, 87 g (0.8 mol) of p-phenylenediamine as diamine, 19 g of 4,4′-diaminodiphenylmethane ( 0.1 mol) and 32 g (0.1 mol) of 2,2′-trifluoromethyl-4,4′-diaminobiphenyl were dissolved in 2,700 g of N-methyl-2-pyrrolidone and reacted at room temperature for 6 hours. And a solution containing polyamic acid was obtained. A small amount of the obtained polyamic acid solution was taken, and N-methyl-2-pyrrolidone was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 80 mPa · s.
Next, 2,000 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 150 g of pyridine and 200 g of acetic anhydride were added, and a 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 further concentrated to obtain 2,260 g of a solution containing 15% by weight of polyimide (pi-4) having an imidation ratio of about 85%. Obtained.
A small amount of this solution was collected, and γ-butyrolactone was added to measure the solution viscosity as a solution having a concentration of 6.0% by weight of 19 mPa · s.

[Synthesis examples of other polyamic acids]
Synthesis example pa-1 (Synthesis example 1 of other polyamic acid)
196 g (1.0 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride as tetracarboxylic dianhydride and 212 g (1, .2) of 2,2′-dimethyl-4,4′-diaminobiphenyl as diamine. 0 mol) is dissolved in a mixed solvent composed of 370 g of N-methyl-2-pyrrolidone and 3,300 g of γ-butyrolactone, and reacted at 40 ° C. for 3 hours to contain 10% by weight of polyamic acid (pa-1). About 4,050 g of a solution was obtained. The solution viscosity of this polyamic acid solution was 210 mPa · s.
Synthesis example pa-2 (Synthesis example 2 of other polyamic acid)
1,2,3,4-cyclobutanetetracarboxylic dianhydride 20 g (0.1 mol) and pyromellitic anhydride 196 g (0.9 mol) as tetracarboxylic dianhydride and 4,4′- as diamine By dissolving 159 g (0.8 mol) of diaminodiphenyl ether and 21 g (0.2 mol) of p-phenylenediamine in 3,600 g of N-methyl-2-pyrrolidone and reacting at 40 ° C. for 4 hours, polyamic acid ( About 4,000 g of a solution containing 10% by weight of pa-2) was obtained. The solution viscosity of this polyamic acid solution was 400 mPa · s.

Example 1
<Preparation of liquid crystal aligning agent>
The amount corresponding to 20 parts by weight in terms of the polyimide (PI-1) in the solution containing the polyimide (PI-1) obtained in Synthesis Example PI-1 and the polyamic obtained in Synthesis Example pa-1 The amount corresponding to 80 parts by weight in terms of the polyamic acid (pa-1) in the solution containing the acid (pa-1) was combined, and this was combined with γ-butyrolactone, N-methyl-2-pyrrolidone and butyl cellosolve. In addition to the weight ratio of butyrolactone: N-methyl-2-pyrrolidone: butyl cellosolve being 71:17:12, N, N, N ′, N′-tetra which is an epoxy compound as an adhesion improver 2 parts by weight of glycidyl-4,4′-diaminodiphenylmethane was added to prepare a solution having a solid content 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.
<Evaluation of coating film thickness uniformity>
The liquid crystal aligning agent prepared above was applied to the transparent electrode surface of the glass substrate with a transparent electrode made of an ITO film using a liquid crystal alignment film printer (Nissha Printing Co., Ltd.), and on a hot plate at 80 ° C. After removing the solvent by heating (pre-baking) for 1 minute, it was heated (post-baking) for 10 minutes on a 200 ° C. hot plate to form a coating film having an average film thickness of 600 mm.
About this coating film, the film thickness in the center part of the board | substrate and the film thickness in the position which approached 15 mm center from the outer side edge of the board | substrate were each measured using the stylus-type film thickness meter (made by KLA Tencor). When the film thickness difference between the two was 15 mm or less, the film thickness uniformity was evaluated as “good”, and when the film thickness difference exceeded 15 mm was evaluated as film thickness uniformity “bad”, the film uniformity was good.

<Manufacture and evaluation of liquid crystal display elements>
[Manufacture of liquid crystal display elements]
The liquid crystal aligning agent prepared above was applied on a transparent conductive film made of an ITO film provided on one surface of a glass substrate having a thickness of 1 mm using a spinner under conditions of a rotation speed of 2,000 rpm and a rotation time of 20 seconds. After heating (pre-baking) at 80 ° C. for 1 minute, the coating film having a thickness of 0.08 μm was formed by heating (post-baking) at 200 ° C. for 1 hour. A rubbing machine having a roll in which a rayon cloth is wound around this coating film is rubbed under conditions of a roll rotation speed of 400 rpm, a stage moving speed of 3 cm / second, and a hair foot indentation length of 0.4 mm. A liquid crystal alignment film was formed by imparting liquid crystal alignment ability to the film. The substrate having the liquid crystal alignment film was subjected to ultrasonic cleaning for 1 minute in ultrapure water and then dried in a clean oven at 100 ° C. for 10 minutes. By repeating the same operation, two substrates (a pair) having a liquid crystal alignment film were obtained.
Next, after applying an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm to each outer edge of the substrate having the liquid crystal alignment film of the pair of liquid crystal alignment films, the liquid crystal alignment film surfaces face each other. The adhesive was cured by overlapping and pressing. 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 orientation About the liquid crystal display element manufactured above, it observed using the microscope. At this time, the liquid crystal alignment was evaluated as “good” when no light leaked, and the liquid crystal alignment as “bad” when light leakage was observed. The liquid crystal alignment of this liquid crystal display element was “good”.
(2) Evaluation of heat resistance (heat stress test)
With respect to the liquid crystal display device manufactured above, a voltage of 5 V was first applied at 60 ° C. with an application time of 60 microseconds and a span of 167 milliseconds, and then the voltage holding ratio after 167 milliseconds from the application release was measured. The numerical value at this time was defined as the initial voltage holding ratio (VHR _BF ). The liquid crystal display element after VHR _BF measurement 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 was measured in the same manner as described above after applying heat stress, and this measured value was taken as voltage holding ratio VHR _AF after heat stress. . These values are shown in Table 2. Further, from the values of VHR _BF and VHR _AF , the following mathematical formula (3)

Table 2 shows the change rate of the voltage holding ratio before and after applying the thermal stress obtained by the above. When the rate of change is less than 2%, the heat resistance is “good”, and when it is 2% or more, the heat resistance is “bad”.
In addition, "VHR-1" manufactured by Toyo Corporation was used for measurement of the voltage holding ratio.

Example 2
<Preparation of liquid crystal aligning agent>
In an amount corresponding to 100 parts by weight in terms of the polyimide (PI-2) in the solution containing the polyimide (PI-2) obtained in Synthesis Example PI-2, γ-butyrolactone, N-methyl 2-pyrrolidone and butyl cellosolve were added so that the weight ratio of γ-butyrolactone: N-methyl-2-pyrrolidone: butyl cellosolve was 40:30:20, and N, which is an epoxy compound as an adhesion improver 2 parts by weight of N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane was added to prepare a solution having a solid content 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 of coating film thickness uniformity>
The film thickness uniformity of the coating film was evaluated in the same manner as in Example 1 except that the liquid crystal aligning agent prepared above was used. The evaluation results are shown in Table 2.
<Manufacture and evaluation of liquid crystal display elements>
In Example 1 above, the rubbing treatment of the coating film formed on the transparent conductive film of the substrate was not performed, and a nematic liquid crystal (MLC-2038, manufactured by Merck & Co., Inc.) showing a negative value of dielectric anisotropy as a liquid crystal was used. A liquid crystal display device was produced in the same manner as in Example 1 except that it was used, and the liquid crystal orientation and heat resistance were evaluated. The evaluation results are shown in Table 2.

Example 3
<Preparation of liquid crystal aligning agent>
In an amount equivalent to 100 parts by weight in terms of the polyimide (PI-3) in the solution containing the imidized polymer (PI-3) obtained in Synthesis Example PI-3, an adhesion improver is added thereto. As an epoxy compound, N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane 10 parts by weight and a functional silane compound methyl 3- [2- (3-trimethoxysilylpropylamino) Ethylamino] propionate (0.75 part by weight) was added, and γ-butyrolactone and butyl cellosolve were added so that the γ-butyrolactone: butyl cellosolve ratio was 90:10 by weight to obtain a solution having a solid content concentration of 4% by weight. A liquid crystal aligning agent was prepared by filtering this solution using a filter having a pore diameter of 1 μm.
<Evaluation of coating film thickness uniformity>
The film thickness uniformity of the coating film was evaluated in the same manner as in Example 1 except that the liquid crystal aligning agent prepared above was used. The evaluation results are shown in Table 2.
<Manufacture and evaluation of liquid crystal display elements>
In Example 1 above, a liquid crystal display element was produced in the same manner as in Example 1 except that nematic liquid crystal (Merck, MLC-2019) having a positive dielectric anisotropy was used as the liquid crystal. The liquid crystal orientation and heat resistance were evaluated. The evaluation results are shown in Table 2.

Example 4
<Preparation of liquid crystal aligning agent>
The amount corresponding to 40 parts by weight in terms of the polyimide (PI-4) in the solution containing the polyimide (PI-4) obtained in Synthesis Example PI-4 and the polyamic obtained in Synthesis Example pa-2 An amount corresponding to 60 parts by weight in terms of the polyamic acid (pa-2) in the solution containing the acid (pa-2) is taken, and N, N, N ′, which is an epoxy compound as an adhesion improver Add 10 parts by weight of N′-tetraglycidyl-4,4′-diaminodiphenylmethane and 0.75 parts by weight of methyl 3- [2- (3-trimethoxysilylpropylamino) ethylamino] propionate, which is a functional silane compound, Further, γ-butyrolactone, N-methyl-2-pyrrolidone and butyl cellosolve are used, and the ratio of γ-butyrolactone: N-methyl-2-pyrrolidone: butyl cellosolve is A weight ratio of 40:40:20 was added to obtain a solution having a solid content concentration of 4% by weight. A liquid crystal aligning agent was prepared by filtering this solution using a filter having a pore diameter of 1 μm.
<Evaluation of coating film thickness uniformity>
The film thickness uniformity of the coating film was evaluated in the same manner as in Example 1 except that the liquid crystal aligning agent prepared above was used. The evaluation results are shown in Table 2.
<Manufacture and evaluation of liquid crystal display elements>
In Example 1 above, a liquid crystal display element was produced in the same manner as in Example 1 except that nematic liquid crystal (Merck, MLC-2019) having a positive dielectric anisotropy was used as the liquid crystal. The liquid crystal orientation and heat resistance were evaluated. The evaluation results are shown in Table 2.

Comparative Example 1
In the said Example 1, it converted into the polyimide (pi-1) of the solution containing the polyimide (pi-1) obtained by the said synthesis example pi-1 instead of the solution containing a polyimide (PI-1). A liquid crystal aligning agent was prepared and evaluated in the same manner as in Example 1 except that the amount corresponding to 20 considerations was used. The evaluation results are shown in Table 2.
Comparative Example 2
In the said Example 2, it converted into the polyimide (pi-2) of the solution containing the polyimide (pi-2) obtained by the said synthesis example pi-2 instead of the solution containing a polyimide (PI-2). A liquid crystal aligning agent was prepared and evaluated in the same manner as in Example 2 except that the amount corresponding to 100 considerations was used. The evaluation results are shown in Table 2.
Comparative Example 3
In the said Example 3, it converted into the polyimide (pi-3) of the solution containing the polyimide (pi-3) obtained by the said synthesis example pi-3 instead of the solution containing a polyimide (PI-3). A liquid crystal aligning agent was prepared and evaluated in the same manner as in Example 3 except that the amount corresponding to 100 considerations was used. The evaluation results are shown in Table 2.
Comparative Example 4
In the said Example 4, it converted into the polyimide (pi-4) of the solution containing the polyimide (pi-4) obtained by the said synthesis example pi-4 instead of the solution containing a polyimide (PI-4). A liquid crystal aligning agent was prepared and evaluated in the same manner as in Example 4 except that the amount corresponding to 40 considerations was used. The evaluation results are shown in Table 2.
In addition, Table 1 shows the compositions of the liquid crystal aligning agents prepared in all Examples and Comparative Examples.

In addition, the abbreviation in the “type” column of the adhesion improver in Table 1 has the following meaning.
Epoxy compound GAPM: N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane functional silane compound MSPP: methyl 3- [2- (3-trimethoxysilylpropylamino) ethylamino] propionate In Table 2, the “Liquid Crystal Name” column has 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 (6)

Tetracarboxylic dianhydride and the following formula (A)

Characterized in that it contains at least one polymer selected from the group consisting of a polyamic acid obtained by reacting with a diamine containing a compound represented by: and a polyimide formed by dehydrating and ring-closing the polyamic acid, Liquid crystal aligning agent.   The liquid crystal aligning agent of Claim 1 whose said tetracarboxylic dianhydride contains 2,3,5- tricarboxycyclopentyl acetic acid dianhydride.   A liquid crystal alignment film formed from the liquid crystal aligning agent according to claim 1.   A liquid crystal display element comprising the liquid crystal aligning agent according to claim 3.   A polyamic acid obtained by reacting a tetracarboxylic dianhydride with a diamine containing a compound represented by the above formula (A).   A polyimide obtained by dehydrating and ring-closing a polyamic acid obtained by reacting a tetracarboxylic dianhydride with a diamine containing a compound represented by the above formula (A).