JP2011039145A - Liquid crystal alignment layer and liquid crystal display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal aligning agent for giving a liquid crystal alignment layer that maintains good liquid crystal aligning property even when the element is continuously driven for a long time, and suppresses reduction in a voltage retention rate and increase in a residual DC voltage. <P>SOLUTION: The liquid crystal aligning agent contains at least one kind of polymer selected from the group consisting of polyamic acids obtained by reacting a tetracarboxylic acid dianhydride with a diamine containing a compound expressed by formula (A), and polyimide produced by dehydrating and ring-closing the polyamic acids. In formula (A), R<SP>I</SP>and R<SP>II</SP>each represent a hydrogen atom or an alkyl group having 1 to 30 carbon atoms; X represents a single bond, a methylene group, an alkylene group having 2 to 30 carbon atoms, -O-, -CO-, -COO-, -NH-, -NHCO- or -CONH-; and n is an integer of 1 to 4. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a liquid crystal alignment film and a liquid crystal display element. More specifically, a liquid crystal aligning agent that provides a liquid crystal alignment film that has excellent liquid crystal alignment properties and little performance deterioration due to long-term continuous driving, and can display high-quality images even when driven for a long time. The present invention relates to a liquid crystal display element in which deterioration of quality 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, and two of them are arranged opposite to each other and nematic liquid crystal having positive dielectric anisotropy in the gap is formed. 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) Documents 4 and 5), an FFS (Fringe Field Switching) type liquid crystal display element (Patent Document 6) is known in which the IPS type electrode structure is changed and the aperture ratio of the display element portion is increased to improve the brightness. Each has excellent viewing angle characteristics.
In addition to these, an OCB (Optical Compensated Bend) type liquid crystal display element (Patent Document 7) that has a 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 5 and 8).
When these liquid crystal display elements having a liquid crystal alignment film are used for television applications and the like, they may be continuously viewed for a long time, and can be driven extremely long time compared to conventional liquid crystal display element applications. Realized. It is known that display quality deteriorates when a conventionally known liquid crystal display element is continuously driven for a long time. One of the reasons is considered that the liquid crystal alignment film is deteriorated by being exposed to heat and light for a long time.
For this reason, in the field of liquid crystal alignment films, materials that do not deteriorate display performance even when driven continuously for a long time have been studied. For example, Patent Document 9 proposes the use of an alignment film material having a crosslinked structure. However, according to the technique described in Patent Document 9, the voltage holding ratio is certainly less lowered when continuously driven for a long time, and long-term reliability in this respect is realized, but the driving time is long. However, there is a problem that the residual DC voltage becomes high and, therefore, the afterimage problem occurs.
There is not yet known a liquid crystal alignment film material that maintains good liquid crystal alignment performance even when continuously driven for a long time and suppresses both a decrease in voltage holding ratio and an increase in residual DC voltage.

JP-A-4-153622 JP 60-107020 A Japanese Patent Laid-Open No. 11-258605 JP 56-91277 A US Pat. No. 5,928,733 JP 2008-216572 A JP 2009-48211A Japanese Patent Laid-Open No. 62-165628 JP 2008-181102 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 its purpose is to maintain good liquid crystal alignment performance even when continuously driven for a long time, and to reduce the voltage holding ratio and the residual DC voltage. An object of the present invention is to provide a liquid crystal aligning agent that provides a liquid crystal aligning film in which both of the increase of the above are suppressed.
Another object of the present invention is to provide a liquid crystal display element capable of high-quality display and having no deterioration in display performance even when continuously driven for a long time.
Still other objects and advantages of the present invention will become apparent from the following description.

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

(In the formula (A), R ^I and R ^II are each a hydrogen atom or an alkyl group having 1 to 30 carbon atoms, X is a single bond, a methylene group, an alkylene group having 2 to 30 carbon atoms, ^* -O -, ^* -CO-, ^* -COO-, ^* -OCO-, ^* -NH-, ^* -NHCO- or ^* -CONH- (in the above, a bond marked with "*" is bonded to a diaminophenyl group. And n is an integer from 1 to 4.)
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,
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 is a liquid crystal aligning film that maintains good liquid crystal aligning performance even when continuously driven for a long time and suppresses both a decrease in voltage holding ratio and an increase in residual DC voltage. Can be formed. Therefore, the liquid crystal display element of the present invention having such a liquid crystal alignment film can display a high quality, and the display quality does not deteriorate even when driven for a long time.
Therefore, 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, portable information terminals, digital cameras, cellular phones, It is suitably applied to display devices such as 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 synthesizing the polyamic acid in the present invention include butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2- Dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dichloro-1,2, 3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetra Carboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3 ′, 4,4′-dicyclohexyltetracarboxylic dianhydride, 2,3,5-to Carboxycyclopentyl acetic acid dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3- Furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5-methyl-5 (tetrahydro-2,5-dioxo-3- Furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5-ethyl-5- (tetrahydro-2,5-dioxo-3) -Furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-7-methyl-5- (tetrahydro-2,5-dioxo- 3-furanyl) -naphtho [1, 2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-7-ethyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1 , 2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho 1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8-ethyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5,8-dimethyl-5- (tetrahydro-2,5-dioxo-3-furanyl ) -Naphtho [1,2-c] -furan-1,3-dione, bicyclo [ 2.2.2] -Oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 3-oxabicyclo [3.2.1] octane-2,4-dione-6-spiro- 3 ′-(tetrahydrofuran-2 ′, 5′-dione), 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride, 3, 5,6-tricarboxy-2-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)

(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.)
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)

And aromatic tetracarboxylic dianhydrides such as compounds represented by each of the above. 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”). It is preferable from the viewpoint of doing so.
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 | combination of the polyamic acid in this invention contains the compound represented by the said Formula (A).
The alkyl group having 1 to 30 carbon atoms of R ^I and R ^II in the above formula (A) is preferably an alkyl group having 1 to 20 carbon atoms, and is an alkyl group having 1 to 10 carbon atoms. Is more preferable, and a linear alkyl group having 1 to 10 carbon atoms is more preferable. Specific examples of the linear alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, and a propyl group.
The combination of R ^I and R ^{II in} the above formula (A) is particularly preferably a compound in which R ^I is a hydrogen atom or a methyl group and R ^II is a methyl group in the above formula (A).
In the above formula (A), the two amino groups bonded to the benzene ring are preferably in the meta position.
In the above formula (A), n is preferably 1. In the above formula (A), when n is 1, two amino groups bonded to the benzene ring are represented by the following formula:

(In the above formula, R ^I , R ^II and X have the same meanings as in the above formula (A)).
Is preferably in the 2,4-position or 3,5-position with respect to the group represented by
Specific examples of the compound represented by the above formula (A) include, for example, the following formulas (A-1) to (A-5):

And the like can be mentioned.
The compound represented by the above formula (A) can be synthesized by combining organic chemistry methods. For example, in the above formula (A), the compound in which X is a single bond includes, for example, dinitrofluorobenzene having n fluorine atoms and (substituted) aziridine having desired groups R ^I and R ^II , preferably potassium carbonate After the reaction at 30 to 80 ° C. in the presence of the nitro group, it can be obtained by reducing (hydrogenating) the nitro group using an appropriate reduction system. In addition, n in this paragraph is synonymous with n in the said Formula (A).
As the diamine for synthesizing the polyamic acid in the present invention, only the compound represented by the above formula (A) may be used alone, or a combination of the compound represented by the above formula (A) and another diamine. May be used.

  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'-diaminobenzo Enone, 3,4'-diaminobenzophenone, 4,4'-diaminobenzophenone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) Phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 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, 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-phenylenedi Isopropylidene) 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-trifluoro) Methyl) phenoxy] - octafluorobiphenyl, 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 (DI) 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 synthesizing 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 is 1 to 50 mol%. It is more preferable that it is included, and it is particularly preferable that 5 to 30 mol% is included. The diamine used in the present invention preferably contains other specific diamine as described above in addition to the compound represented by the above formula (A). In this case, the use ratio of the other specific diamine is preferably 30 mol% or more, more preferably 50 to 99 mol%, particularly 70 to 95 mol% with respect to the total diamine. Is preferred.
The diamine used for synthesizing the polyamic acid in the present invention is preferably composed only of the compound represented by the above formula (A) and other specific diamine.

[Synthesis of polyamic acid]
In the present invention, the polyamic acid 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. 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 methanol, ethanol, isopropanol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, 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 at least one 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. 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>
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 contained in the liquid crystal aligning agent of 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 contained in the liquid crystal aligning agent of the present invention may be a completely imidized product obtained by dehydrating and cyclizing all of the amic acid structure that the polyamic acid as a raw material had, and only a part of the amic acid structure is dehydrated. It may be a partially imidized product that is ring-closed and has an amic acid structure and an imide ring structure.
The polyimide contained in the liquid crystal aligning agent of the present invention preferably has an imidization rate of 30% 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 liquid crystal aligning agent of this invention contains only the polyimide formed by spin-drying | dehydrating and ring-closing the polyamic acid obtained by making tetracarboxylic dianhydride and the diamine containing the compound represented by the said Formula (A) react as a polymer. When it does, it is preferable that the imidation ratio of this polyimide is 30 to 80%, and it is more preferable that it is 30 to 70%. On the other hand, a preferable imidation ratio in the case where the liquid crystal aligning agent of the present invention further contains another polymer in addition to the polyimide will be described later.

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. The proportion of the dehydrating agent to be used should be appropriately set depending on the desired imidization ratio, but is preferably 0.01 to 20 mol with respect to 1 mol of the amic acid structure of the 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 use ratio of the dehydration ring-closing catalyst is preferably 0.01 to 10 mol with respect to 1 mol of the dehydrating agent used. The imidization rate can be increased as the use ratio of the dehydrating agent and dehydrating ring-closing agent is increased. 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 above method (ii), a reaction solution containing polyimide is obtained. This reaction solution 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 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 dehydrating ring-closing 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-decylsuccinic anhydride, n-dodecylsuccinic anhydride, n-tetradecylsuccinic 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 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 10% by weight solution is obtained. It is more preferable that it has.
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, compounds having at least one epoxy group in the molecule (hereinafter referred to as “epoxy compound”), and functional silane compounds.

[Other polymers]
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 obtained by dehydration and ring closure, and the same shall apply hereinafter)), preferably 90% by weight or less, more preferably 80% by weight or less.
When using a polymer other than this together with a polyimide formed by dehydrating and ring-closing a polyamic acid obtained by reacting a tetracarboxylic dianhydride and a diamine containing the compound represented by the above formula (A), At least one selected from the group consisting of a polyamic acid obtained by reacting a carboxylic dianhydride and a diamine containing the compound represented by the above formula (A) and a polyimide formed by dehydrating and ring-closing the polyamic acid. The average imidation ratio of the polymer and other polymers is preferably 70% or less, more preferably 10 to 60%, and even more preferably 15 to 50%. This average imidation ratio is the total number of imide ring structures (PI-I) and total number of amic acid structures (PI-A) of polyimide contained in the liquid crystal aligning agent, and the total number of amic acid structures of polyamic acid (PA-A). ) From the following formula (1)

The value calculated by.
[Epoxy compound]
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'-diaminodiphenylme Emissions, 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.

[Functional silane compounds]
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-glycidoxypropyltrimethoxysilane, and 3-glycidoxypropyl triethoxy silane 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 polyamic acid and polyimide as described above and other additives optionally blended as necessary are preferably in an organic solvent. It is composed by being dissolved in.
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 admixture of two or more.
The solid content concentration in the liquid crystal aligning agent of the present invention (the ratio of the total weight of components other than the solvent of the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) 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 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 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) 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 a transparent conductive film provided on one surface of the substrate, an NESA film (registered trademark of PPG, USA) made of tin oxide (SnO ₂ ), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ), 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 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-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, 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 the amic acid unit in a polymer 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 spinner 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 liquid crystal display element, the coating film formed as described above can be used as a liquid crystal alignment film as it is. 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 a liquid crystal molecule is provided to a coating film, and it becomes a liquid crystal aligning 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 sealant 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. 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, a nematic liquid crystal, a smectic liquid crystal, or the like can be used, and among these, a 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, a dicyanobenzene liquid crystal, a pyridazine liquid crystal, a Schiff base liquid crystal, an azoxy liquid crystal, a biphenyl liquid crystal, or a phenylcyclohexane liquid crystal is 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. For example, cholesteric liquid crystals such as cholestyl chloride, cholesteryl nonate, and cholesteryl carbonate; chiral agents such as those sold under the trade names C-15 and CB-15 (Merck); p-decyloxybenzylidene Ferroelectric liquid crystals such as -p-amino-2-methylbutyl cinnamate may be further 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 in which a polarizing film called “H film” in which iodine is absorbed while polyvinyl alcohol is stretched and oriented is sandwiched between cellulose acetate protective films The polarizing plate which consists of itself can be mentioned.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. In the following synthesis examples, the solution viscosity of the polymer and the imidation ratio of the polyimide were evaluated by the following methods.
[Solution viscosity of polymer]
The solution viscosity (mPa · s) of the polymer was measured at 25 ° C. using an E-type rotational viscometer for the polymer solution prepared at a predetermined concentration using the predetermined solvent described in each synthesis example.
[Imidation rate of polyimide]
The imidization rate of polyimide is determined by adding a solution containing polyimide into pure water, drying the precipitate sufficiently at room temperature, dissolving in deuterated dimethyl sulfoxide, and using tetramethylsilane as a reference material at room temperature. From the ¹ H-NMR spectrum measured by the following formula (2)
Imidation rate (%) = (1-A ¹ / A ² × α) × 100 (2)
(In Formula (2), A ¹ is the area of the peak derived from the proton of the NH group appearing near the chemical shift of 10 ppm, A ² is the area of the peak derived from the other proton, and α is the precursor of the polyimide. (This is the ratio of the number of other protons to one proton of the NH group in (polyamic acid).)
Determined by
<Synthesis Example of Compound Represented by Formula (A)>
Synthesis Example A-1
Scheme 1 below

Thus, compound (A-1) was synthesized.
In a 500 mL three-necked flask under a nitrogen atmosphere, 3,5-dinitrofluorobenzene 100.0 mmol (18.61 g), potassium carbonate 150.0 mmol (20.73 g), 2-methylaziridine 200.0 mmol (11.42 g) and dimethyl 200 mL of acetamide was charged, and the reaction was performed at 40 ° C. with stirring for 8 hours. After completion of the reaction, 300 mL of ethyl acetate was added to the reaction mixture to recover the organic layer. The obtained organic layer was washed with distilled water, dehydrated with magnesium sulfate, and then the solvent was removed using a rotary evaporator, thereby obtaining 90.6 mmol of 1- (3,5-dinitrophenyl) -2-methylaziridine. (20.21 g) was obtained (yield 90.6%).
Subsequently, 90.6 mmol (20.21 g) of 1- (3,5-dinitrophenyl) -2-methylaziridine obtained above, 5.54 g of 5 wt% palladium / carbon and ethanol were added to a 500 mL three-necked flask under a nitrogen atmosphere. 300 mL was charged and stirred at 70 ° C. for 1 hour. To this, 90 mL of hydrazine monohydrate was added dropwise over 1 hour, and the reaction was further carried out at 90 ° C. with stirring for 3 hours. After completion of the reaction, the reaction mixture was filtered through Celite to remove palladium / carbon, and then the solvent was removed under reduced pressure to obtain a solid. The obtained solid is purified by column chromatography (filler: silica gel, developing solvent: chloroform / ethanol = 95/5 (volume ratio)) to give 1- (3,5-diaminophenyl) -2-methyl. 67.4 mmol (11.01 g) of aziridine (compound (A-1)) was obtained.
Synthesis Example A-2
Scheme 2 below

Then, 1- (2,4-diaminophenyl) -2-methylaziridine (compound (A-2)) was synthesized.
In a 500 mL three-necked flask under a nitrogen atmosphere, 2,4-dinitrofluorobenzene 100.0 mmol (18.61 g), potassium carbonate 150.0 mmol (20.73 g), 2-methylaziridine 200.0 mmol (11.42 g) and dimethyl 200 mL of acetamide was charged, and the reaction was performed at 40 ° C. with stirring for 8 hours. After completion of the reaction, 300 mL of ethyl acetate was added to the reaction mixture to recover the organic layer. The obtained organic layer was washed with distilled water, dehydrated with magnesium sulfate, and then the solvent was removed using a rotary evaporator, whereby 92.4 mmol of 1- (2,4-dinitrophenyl) -2-methylaziridine ( (20.62 g) was obtained (yield 92.4%).
Then, in a 500 mL three-necked flask under a nitrogen atmosphere, 92.4 mmol (20.62 g) of 1- (2,4-dinitrophenyl) -2-methylaziridine obtained above, 5.54 g of 5 wt% palladium / carbon and 300 mL of ethanol were obtained. And stirred at 70 ° C. for 1 hour. To this, 90 mL of hydrazine monohydrate was added dropwise over 1 hour, and the reaction was further carried out at 90 ° C. with stirring for 3 hours. After completion of the reaction, the reaction mixture was filtered through Celite to remove palladium / carbon, and then the solvent was removed under reduced pressure to obtain a solid. The obtained solid is purified by column chromatography (filler: silica gel, developing solvent: chloroform / ethanol = 95/5 (volume ratio)) to give 1- (2,4-diaminophenyl) -2-methyl. 68.8 mmol (11.23 g) of aziridine (compound (A-2)) was obtained.

<Polyimide synthesis example>
Synthesis example PI-1
11.2 g (0.050 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 15.7 g (0.050 mol), p-phenylenediamine 7.2 g (0. 067 mol), 1,3-bis (3-aminopropyl) -tetramethyldisiloxane 2.5 g (0.010 mol), 3,6-bis (4-aminobenzoyloxy) cholestane 0.96 g (0.0015 Mol) and 3.3 g (0.020 mol) of the compound (A-2) obtained in Synthesis Example A-2 and 0.28 g (0.0030 mol) of aniline as a monoamine It was dissolved in chilled 2-pyrrolidone 96 g, by performing the reaction for 6 hours at 60 ° C., to obtain a solution containing a polyamic acid. A small amount of the obtained polyamic acid solution was collected, and N-methyl-2-pyrrolidone was added to measure the solution viscosity as a solution having a polyamic acid concentration of 10% by weight of 60 mPa · s.
Next, 270 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 40 g of pyridine and 41 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration ring closure reaction, the solvent in the system was replaced with new γ-butyrolactone (the pyridine and acetic anhydride used for the dehydration ring closure reaction were removed from the system in this operation. The same applies hereinafter). 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 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 16 mPa · s.

Synthesis example PI-2
22 g (0.10 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as tetracarboxylic dianhydride and 6.4 g (0.060 mol) of p-phenylenediamine as diamine, 3 (3,5- 10 g (0.020 mol) of diaminobenzoyloxy) cholestane and 3.3 g (0.020 mol) of the compound (A-2) obtained in Synthesis Example A-2 were dissolved in 166 g of N-methyl-2-pyrrolidone. By reacting at 60 ° C. for 6 hours, a solution containing polyamic acid was obtained. A small amount of the obtained polyamic acid solution was collected, and N-methyl-2-pyrrolidone was added to measure the solution viscosity as a solution having a polyamic acid concentration of 10% by weight of 60 mPa · s.
Next, 190 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 8 g of pyridine and 10 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 N-methyl-2-pyrrolidone to obtain a solution containing about 15% by weight of polyimide (PI-2) having an imidization ratio of about 50%. . 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 47 mPa · s.

Synthesis example PI-3
11.2 g (0.050 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 15.7 g (0.050 mol), p-phenylenediamine 7.2 g (0. 067 mol), 1,3-bis (3-aminopropyl) -tetramethyldisiloxane 2.5 g (0.010 mol), 3,6-bis (4-aminobenzoyloxy) cholestane 0.96 g (0.0015 Mol) and 3.3 g (0.020 mol) of the compound (A-1) obtained in Synthesis Example A-1 and 0.28 g (0.0030 mol) of aniline as a monoamine It was dissolved in chilled 2-pyrrolidone 96 g, by performing the reaction for 6 hours at 60 ° C., to obtain a solution containing a polyamic acid. A small amount of the obtained polyamic acid solution was collected, and N-methyl-2-pyrrolidone was added to measure the solution viscosity as a solution having a polyamic acid concentration of 10% by weight of 60 mPa · s.
Next, 270 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 40 g of pyridine and 41 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 a solution containing about 15% by weight of polyimide (PI-3) having an imidation ratio of about 95%. 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 16 mPa · s.

Synthesis example PI-4
22 g (0.10 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as tetracarboxylic dianhydride and 6.4 g (0.060 mol) of p-phenylenediamine as diamine, 3 (3,5- 10 g (0.020 mol) of diaminobenzoyloxy) cholestane and 3.3 g (0.020 mol) of the compound (A-1) obtained in Synthesis Example A-1 were dissolved in 166 g of N-methyl-2-pyrrolidone. By performing the reaction at 60 ° C. for 6 hours, a solution containing polyamic acid was obtained. A small amount of the obtained polyamic acid solution was collected, and N-methyl-2-pyrrolidone was added to measure the solution viscosity as a solution having a polyamic acid concentration of 10% by weight of 60 mPa · s.
Next, 190 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 8 g of pyridine and 10 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 N-methyl-2-pyrrolidone to obtain a solution containing about 15% by weight of polyimide (PI-4) having an imidization ratio of about 50%. . 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 47 mPa · s.

<Synthesis examples of other polymers>
[Synthesis examples of other polyamic acids]
Synthesis example PA-1
1,2,3,4-cyclobutanetetracarboxylic dianhydride 98 g (0.50 mol) and pyromellitic dianhydride 109 g (0.50 mol) as tetracarboxylic dianhydride and 4,4 ′ as diamine 198 g (1.0 mol) of diaminodiphenylmethane was dissolved in a mixed solvent consisting of 230 g of N-methyl-2-pyrrolidone and 2,060 g of γ-butyrolactone, reacted at 40 ° C. for 3 hours, γ-butyrolactone 1, By adding 350 g, a solution containing 7.7% by weight of polyamic acid (PA-1) was obtained. The solution viscosity of this solution was 125 mPa · s.

[Synthesis example of other polyimides]
Synthesis example PI-5
110 g (0.50 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride and 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro -2,5-dioxo-3-furanyl) naphtho [1,2-c] furan-1,3-dione 160 g (0.50 mol), p-phenylenediamine 94 g (0.87 mol) as diamine, 1, 25 g (0.10 mol) of 3-bis (3-aminopropyl) tetramethyldisiloxane and 9.6 g (0.015 mol) of 3,6-bis (4-aminobenzoyloxy) cholestane and octadecylamine as monoamine. 1 g (0.030 mol) was dissolved in 960 g of N-methyl-2-pyrrolidone and reacted at 60 ° C. for 6 hours, To obtain a solution containing click acid. A small amount of the obtained polyamic acid solution was collected, and N-methyl-2-pyrrolidone was added to measure the solution viscosity as a solution having a polyamic acid concentration of 10% by weight of 60 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 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 a solution containing about 15% by weight of polyimide (PI-5) having an imidation ratio of about 95%. A small amount of the obtained polyimide solution was collected, 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 PI-6
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 A solution containing polyamic acid was obtained by dissolving 52 g (0.10 mol) of oxy) cholestane in 830 g of N-methyl-2-pyrrolidone and reacting at 60 ° C. for 6 hours. A small amount of the obtained polyamic acid solution was collected, and N-methyl-2-pyrrolidone was added to measure the solution viscosity as a solution having a polyamic acid concentration of 10% by weight of 60 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 closure 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-6) having an imidization ratio of about 50%. . 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 47 mPa · s.

<Preparation and evaluation of liquid crystal aligning agent>
Example 1
(I) Preparation of liquid crystal aligning agent A solution containing the polyimide (PI-1) obtained in Synthesis Example PI-1 and a solution containing the polyamic acid (PA-1) obtained in Synthesis Example PA-1 Polyimide (PI-1): Polyamic acid (PA-1) = 20: 80 (weight ratio) mixed so that γ-butyrolactone (BL), N-methyl-2-pyrrolidone (NMP) and butyl cellosolve (BC) is added, and further, 10 parts by weight of N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane as an epoxy compound is added to 100 parts by weight of the polymer, and the mixture is sufficiently stirred. The solvent composition was BL: NMP: BC = 71: 17: 12 (weight ratio) and the solid content concentration was 6.0 wt%. A liquid crystal aligning agent was prepared by filtering this solution using a filter having a pore diameter of 1 μm.
(II) Evaluation of liquid crystal aligning agent (1) Manufacture of liquid crystal cell Glass substrate with transparent electrode made of ITO film using liquid crystal aligning agent prepared above using liquid crystal alignment film printer (Nissha Printing Co., Ltd.) The film was coated on the transparent electrode surface, heated on a hot plate at 80 ° C. for 1 minute (pre-baked) to remove the solvent, and then heated on a hot plate at 200 ° C. for 10 minutes (post-baked) to obtain an average film thickness of 600 mm. The coating film was formed. The coating film is rubbed with a rubbing machine having a roll wrapped with a rayon cloth at a roll rotation speed of 500 rpm, a stage moving speed of 3 cm / sec, and a hair foot indentation length of 0.4 mm to give liquid crystal alignment ability. did. Thereafter, ultrasonic cleaning was performed in ultrapure water for 1 minute, followed by drying in a 100 ° C. clean oven for 10 minutes to obtain a substrate having a liquid crystal alignment film.
This operation was repeated to obtain a pair (two) of substrates having a liquid crystal alignment film.
Next, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm was applied to the outer edges of the pair of substrates having the liquid crystal alignment film, and then the liquid crystal alignment film surfaces were overlapped and pressure bonded. Later, the adhesive was cured. Next, after filling nematic liquid crystal (MLC-6221 manufactured by Merck & Co., Inc.) between a pair of substrates from the liquid crystal injection port, the liquid crystal injection port is sealed with an acrylic photo-curing adhesive to produce a liquid crystal cell. did.

(2) Evaluation of liquid crystal cell (i) Evaluation of light resistance After applying a voltage of 5 V at 70 ° C. with an application time of 60 microseconds and a span of 167 milliseconds to the liquid crystal cell produced as described above, The voltage holding ratio 167 milliseconds after the application release was measured by “VHR-1” manufactured by Toyo Corporation (initial voltage holding ratio: A). As a result, the initial voltage holding ratio was 99.7%.
Next, the liquid crystal cell after the initial voltage holding ratio measurement was subjected to an irradiation test for 5,000 hours with a weather meter using a carbon arc as a light source. With respect to the liquid crystal cell after the irradiation test, the voltage holding ratio was measured again by the same method as described above (voltage holding ratio after irradiation: B).
At this time, when the ratio (B / A) of the voltage holding ratio after irradiation to the initial voltage holding ratio was 90% or more, the light resistance was evaluated as “good”, and when the ratio was less than 90%, the light resistance was evaluated as “bad”. As a result, the light resistance of the liquid crystal cell was “good”.
(Ii) Evaluation of residual DC voltage For the liquid crystal cell manufactured as described above, the DC voltage of the liquid crystal cell was measured by the flicker elimination method (initial DC voltage). Subsequently, a voltage of DC 17V was applied to the liquid crystal cell whose initial DC voltage was measured at 100 ° C. for 20 hours. With respect to the liquid crystal cell after the voltage application, 15 minutes after the DC power supply was released, the DC voltage in the liquid crystal cell was measured again by the flicker elimination method (DC voltage after voltage application). At this time, a value obtained by subtracting the initial DC voltage from the DC voltage after voltage application was defined as a residual DC voltage.
When the residual DC voltage was less than 500 mV, the residual DC voltage was evaluated as “good”, and when the residual DC voltage was 500 mV or higher, the residual DC voltage was evaluated as “defective”. there were.

Examples 2-5 and Comparative Examples 1-5
In Example 1 above, the type and amount of the polymer used and the amount of epoxy compound N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane used are shown in Table 1, respectively. A liquid crystal aligning agent was prepared in the same manner as in Example 1, and a liquid crystal cell was produced and evaluated. The evaluation results are shown in Table 1.

Example 6
(I) Preparation of liquid crystal aligning agent N-methyl-2-pyrrolidone (NMP) and butyl cellosolve (BC) are added to the solution containing the polyimide (PI-2) obtained in Synthesis Example PI-2, and an epoxy compound is further added. N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane is added in an amount of 10 parts by weight with respect to a total of 100 parts by weight of the polymer and sufficiently stirred, and the solvent composition is NMP: BC = 50. : 50 (weight ratio) and a solid content concentration of 6.0% by weight. A liquid crystal aligning agent was prepared by filtering this solution using a filter having a pore diameter of 1 μm.
(II) Evaluation of liquid crystal aligning agent (1) Manufacture of liquid crystal cell Glass substrate with transparent electrode made of ITO film using liquid crystal aligning agent prepared above using liquid crystal alignment film printer (Nissha Printing Co., Ltd.) The film was coated on the transparent electrode surface, heated on a hot plate at 80 ° C. for 1 minute (pre-baked) to remove the solvent, then heated on a hot plate at 200 ° C. for 10 minutes (post-baked), and an average film thickness of 600 mm A coating film (liquid crystal alignment film) was formed. This operation was repeated to obtain a pair (two) of substrates having a liquid crystal alignment film.
Next, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm was applied to the outer edges of the pair of substrates having the liquid crystal alignment film, and then the liquid crystal alignment film surfaces were overlapped and pressure bonded. Later, the adhesive was cured. Next, after filling nematic liquid crystal (MLC-6608, manufactured by Merck & Co., Inc.) between a pair of substrates from the liquid crystal injection port, the liquid crystal injection port is sealed with an acrylic photo-curing adhesive to produce a liquid crystal cell. did.
(2) Evaluation of liquid crystal cell When the light resistance and the residual DC voltage were evaluated in the same manner as in Example 1 using the liquid crystal cell produced as described above, the initial voltage holding ratio was 99. The light resistance and the residual DC voltage were both “good”.
Examples 7 to 10 and Comparative Examples 6 to 10
In Example 6 above, the type of polyimide used and the amount of N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane, which is an epoxy compound, were as shown in Table 2, respectively. In the same manner as in Example 6, a liquid crystal aligning agent was prepared, and a liquid crystal cell was produced and evaluated. The evaluation results are shown in Table 2.

Claims (8)

Tetracarboxylic dianhydride and the following formula (A)

(In the formula (A), R ^I and R ^II are each a hydrogen atom or an alkyl group having 1 to 30 carbon atoms, X is a single bond, a methylene group, an alkylene group having 2 to 30 carbon atoms, ^* -O -, ^* -CO-, ^* -COO-, ^* -OCO-, ^* -NH-, ^* -NHCO- or ^* -CONH- (in the above, a bond marked with "*" is bonded to a diaminophenyl group. And n is an integer from 1 to 4.)
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. 2. The liquid crystal aligning agent according to claim 1, wherein R ^I in the formula (A) is a hydrogen atom or a methyl group, and R ^II is a methyl group.   The liquid crystal aligning agent of Claim 1 or 2 whose said tetracarboxylic dianhydride contains 2,3,5- tricarboxycyclopentyl acetic acid dianhydride.   A liquid crystal aligning film formed from the liquid crystal aligning agent according to claim 1.   A liquid crystal display element comprising the liquid crystal alignment film according to claim 4.   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).   Compound represented by the above formula (A).