JP2008107814A - Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element - Google Patents

Abstract

The present invention provides a liquid crystal alignment film that provides a liquid crystal alignment film that reduces accumulated charges while maintaining a voltage holding ratio, and further has excellent printability.
The following formula (I):

(Wherein R _{1 to} R ₈ are each independently a hydrogen atom, an alkyl group or an alkoxy group, and R _{9 to} R ₁₂ are each independently a hydrogen atom, an aromatic group, an aliphatic group or an epoxy group) An aliphatic group substituted with a group, A is an aliphatic group substituted with a hydrogen atom, an aliphatic group or an epoxy group, and n is an integer of 1 to 100.)
Liquid crystal aligning agent containing the compound represented by these.
[Selection figure] None

Description

  The present invention relates to a liquid crystal aligning agent, a liquid crystal alignment film, and a liquid crystal display element. More specifically, the present invention relates to a liquid crystal alignment agent that provides a liquid crystal alignment film having good electrical characteristics and good printability, the liquid crystal alignment film, and a liquid crystal display element containing the liquid crystal alignment film.

Currently, as a liquid crystal display element, a liquid crystal alignment film made of polyamic acid, polyimide, or the like is formed on the surface of a substrate on which a transparent conductive film is provided to form a liquid crystal display element substrate. A nematic liquid crystal layer having positive dielectric anisotropy is formed in a cell having a sandwich structure so that the major axis of the liquid crystal molecules is continuously twisted 90 degrees from one substrate to the other. A TN liquid crystal display element having a so-called TN (twisted nematic) liquid crystal cell is known. Further, STN (Super Twisted Nematic) type liquid crystal display elements and vertical alignment type liquid crystal display elements, which have a higher contrast than the TN type liquid crystal display elements and have less viewing angle dependency, have been developed. This STN type liquid crystal display element uses nematic liquid crystal blended with a chiral agent which is an optically active substance as liquid crystal, and the major axis of liquid crystal molecules is continuously twisted over 180 degrees between substrates. The birefringence effect generated by the above is utilized. On the other hand, as described in Non-Patent Document 1 and Patent Document 1, a vertically aligned liquid crystal display element called an MVA method has been proposed in which protrusions are formed on ITO to control the alignment direction of liquid crystals. Yes. The MVA liquid crystal display element is excellent in terms of manufacturing process, such as excellent viewing angle and contrast, and need not be rubbed in forming the liquid crystal alignment film. As a liquid crystal alignment film suitable for the TN, STN, and MVA methods, performance such as a short afterimage erasing time of the liquid crystal display element is required. In addition, as an alignment agent used for forming these liquid crystal alignment films, excellent printability is required in offset printing.
“Liquid Crystal” Vol. 3 No. 2 117 (1999) Japanese Patent Laid-Open No. 11-258605

The present invention has been made in view of the above problems, and an object thereof is to reduce accumulated charges while maintaining a voltage holding ratio. An object of the present invention is to provide a liquid crystal aligning agent provided with a liquid crystal alignment film and having excellent printability, the liquid crystal alignment film, and a liquid crystal display element using the liquid crystal alignment film.
Still other objects and advantages of the present invention will become apparent from the following description.

In accordance with the present invention, the above objects and advantages of the present invention are primarily as follows:
The following formula (I):

(Wherein R _{1 to} R ₈ are each independently a hydrogen atom, an alkyl group or an alkoxy group, and R _{9 to} R ₁₂ are each independently a hydrogen atom, an aromatic group, an aliphatic group or An aliphatic group substituted with an epoxy group, A is an aliphatic group substituted with a hydrogen atom, an aliphatic group or an epoxy group, and n is an integer of 1 to 100.)
It is achieved by the liquid crystal aligning agent characterized by containing the compound (henceforth a specific compound) represented by these.

In the above formula _(I), R 1 ~R ₈ are each independently a hydrogen atom, an alkyl group or an alkoxy group having 1 to 6 carbon atoms having 1 to 6 carbon _atoms, both R 9 _{to R 12} is A compound which is a hydrogen atom, A is a hydrogen atom, and n is an integer of 1 to 100 is a preferable compound.
In the above formula (I), R _{1 to} R ₈ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, and R ₉ and R ₁₁ are aromatic. R ₁₀ and R ₁₂ are a hydrogen atom or an aliphatic group, A is a hydrogen atom or an aliphatic group, and a compound in which n is an integer of 1 to 100 is another preferred compound.
Moreover, in said formula (I), R < ₁ > -R < ₈ > is respectively independently a hydrogen atom, a C1-C6 alkyl group, or a C1-C6 alkoxy group, and R < ₉ > and R <_11> are An aromatic group in which R ₁₀ and R ₁₂ are substituted with a hydrogen atom or an epoxy group, A is an aliphatic group substituted with a hydrogen atom or an epoxy group, and n is an integer of 1 to 100 Is a more preferred compound.

According to the present invention, the above objects and advantages of the present invention are secondly,
In the above formula (I), R _{1 to} R ₈ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms, and any of R _{9 to} R ₁₂ is Is a hydrogen atom, A is a hydrogen atom, and n is an integer of 1 to 100. A polyamic acid polymer obtained by reaction of tetracarboxylic dianhydride (hereinafter referred to as a specific polyamic acid polymer). It is achieved by a liquid crystal aligning agent characterized by containing

  Moreover, the liquid crystal aligning agent of this invention is shown by the polyamic acid which consists of at least 1 sort (s) among the said specific compound and the said specific polyamic acid polymer, and the repeating unit shown by following formula (I-1), and (I-2). And at least one polymer selected from the group consisting of polyimides composed of repeating units.

(Where P ¹ is a tetravalent organic group and Q ¹ is a divalent organic group)

(Where P ² is a tetravalent organic group and Q ² is a divalent organic group)

Hereinafter, the present invention will be described in detail.
The liquid crystal aligning agent of the present invention is preferably constituted by dissolving at least one of a specific compound and a specific polyamic acid polymer and at least one polymer selected from polyamic acid and polyimide in an organic solvent.
[Specific compounds]
In the formula (I), R _{1 to} R ₈ are each independently a hydrogen atom, an alkyl group or an alkoxy group. The alkyl group and alkoxyl group are preferably an alkyl group having 1 to 6 carbon atoms and an alkoxy group having 1 to 6 carbon atoms. Examples of the alkyl group and the alkyl group contained in the alkoxy group include a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, 2-methyl-propyl group, 3-methyl-propyl group, n- Examples include a pentyl group and an n-hexyl group. R _{9 to} R ₁₂ are each independently an aliphatic group substituted with a hydrogen atom, an aromatic group, an aliphatic group or an epoxy group. A hydrogen atom, a phenyl group, a naphthyl group, an aliphatic group having 1 to 4 carbon atoms or an aliphatic group substituted with an epoxy group is preferable, and specifically, a methyl group, an ethyl group, a propyl group, a butyl group, or a glycidyl group. Can be mentioned. A is preferably a hydrogen atom, an aliphatic group having 1 to 4 carbon atoms or an aliphatic group substituted with an epoxy group, and specific examples include a methyl group, an ethyl group, a propyl group, a butyl group, and a glycidyl group. it can. Moreover, n is an integer of 1-100.
Particularly preferably, R _{1 to} R ₈ are hydrogen, R _{9 to} R ₁₂ are each independently a hydrogen atom, a methyl group, an ethyl group, a phenyl group, or a glycidyl group, and A is a hydrogen atom. Or it is a glycidyl group.
Specific compounds include the following compounds.

In the specific compounds, when R ₉ to R ₁₂ are each a hydrogen atom, is reacted with an acid dianhydride can be obtained a specific polyamic acid polymer. In synthesizing the polymer of the specific polyamic acid, preferred examples of the acid dianhydride include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-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, cis-3,7-dibutylcycloocta-1,5-diene-1,2,5,6-tetracarboxylic dianhydride 3,5,6-tricarbonyl-2-carboxynorbornane-2: 3,5: 6-dianhydride, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro 2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 3-oxabicyclo [3.2.1] octane-2,4-dione-6-spiro- 3 ′-(tetrahydrofuran-2 ′, 5′-dione), 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride, 3, 5,6-tricarboxy-2-carboxynorbornane-2: 3,5: 6-dianhydride, 4,9-dioxatricyclo "5.3.1.0 ^2,6 " undecane-3,5 Examples thereof include 8,10-tetraone and pyromellitic dianhydride. These acid dianhydrides can be used alone or in combination of two or more.

  At this time, in addition to the specific compound having a diamine structure, another diamine compound may be used in combination. As other preferable diamine compounds, for example, p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl sulfide, 2,2′-dimethyl-4,4′-diaminobiphenyl, 1,5-diamino Naphthalene, 2,7-diaminofluorene, 9,9-dimethyl-2,7-diaminofluorene, 4,4′-diaminodiphenyl ether, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 9, 9-bis (4-aminophenyl) fluorene, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4 ′ -(P-phenylenediisopropylidene) bisaniline, 4,4 '-(m-phenylenediisopropyl Pyridene) bisaniline, 1,4-cyclohexanediamine, 4,4′-methylenebis (cyclohexylamine), 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, 2 , 6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminoacridine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, N-ethyl-3 , 6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N, N'-di (4-aminophenyl) -benzidine, N, N'-di (4-aminophenyl) -N, N'- Examples thereof include dimethyl-benzidine. These other diamine compounds can be used alone or in combination of two or more.

[Polyamic acid]
<Tetracarboxylic dianhydride>
In the present invention, the tetracarboxylic dianhydride used for the synthesis of the polyamic acid other than the specific polyamic acid polymer is preferably an alicyclic tetracarboxylic dianhydride. Examples of the alicyclic tetracarboxylic dianhydride include 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride. 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dichloro-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2, 3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetra Carboxylic dianhydride, 3,3 ′, 4,4′-dicyclohexyltetracarboxylic dianhydride, cis-3,7-dibutylcycloocta-1,5-diene-1,2,5,6-tetracarboxylic Acid dianhydride 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 3,5,6-tricarbonyl-2-carboxynorbornane-2: 3,5: 6-dianhydride, 2,3,4,5-tetrahydrofurantetra Carboxylic 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, 5- (2,5-dioxotetrahydrofural) -3-methyl-3-cyclohexene-1,2-dicarboxylic Acid dianhydride, bicyclo [2.2.2] -oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 3-oxabicyclo [3.2.1] octane-2, 4-dione-6-spiro-3 ′-(tetrahydrofuran-2 ′, 5′-dione), 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2 Dicarboxylic acid anhydride, 3,5,6-tricarboxy-2-carboxynorbornane-2: 3,5: 6-dianhydride, 4,9-dioxatricyclo "5.3.1.0 ^{2, 6} "undecane-3,5,8,10-tetraone, below Compounds represented by formulas (II) and (III),

(Wherein R ¹ and R ³ represent a divalent organic group having an aromatic ring, R ² and R ⁴ represent a hydrogen atom or an alkyl group, and a plurality of R ² and R ⁴ are the same. But it may be different.)
In addition, aliphatic tetracarboxylic dianhydrides such as butanetetracarboxylic dianhydride;
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) and aromatic tetracarboxylic dianhydrides such as compounds represented by the following formulas (1) to (4). These may be used alone or in combination of two or more.

Among the tetracarboxylic dianhydrides, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,5-tricarboxy Cyclopentyl acetic acid dianhydride, 5- (2,5-dioxotetrahydrofural) -3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, cis-3,7-dibutylcycloocta-1,5 -Diene-1,2,5,6-tetracarboxylic dianhydride, 3,5,6-tricarbonyl-2-carboxynorbornane-2: 3,5: 6-dianhydride, 1,3,3a, 4,5,9b- Xahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8- Methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5 8-Dimethyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, bicyclo [2.2.2] -oct-7-ene -2,3,5,6-tetracarboxylic dianhydride, 3-oxabicyclo [3.2.1] octane-2,4-dione-6-spiro-3 '-(tetrahydrofuran-2', 5 ' -Dione), 5- (2,5-dioxotetrahydro-3-fura ) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 3,5,6-tricarboxy-2-carboxynorbornane-2: 3,5: 6-dianhydride, 4,9- Dioxatricyclo “5.3.1.0 ^2,6 ” undecane-3,5,8,10-tetraone, among the compounds represented by the above formula (II), the following formulas (5) to (7) An alicyclic tetracarboxylic dianhydride such as a compound represented by the following formula (8) among the compounds represented by the above formula (III) and the alicyclic tetracarboxylic dianhydride such as a compound represented by: From the standpoint of achieving good liquid crystal orientation. Particularly preferred are 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tri Carboxycyclopentyl acetic acid dianhydride, 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3 -Dione, cis-3,7-dibutylcycloocta-1,5-diene-1,2,5,6-tetracarboxylic dianhydride, 3,5,6-tricarbonyl-2-carboxynorbornane-2: 3,5: 6-dianhydride, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2- c] Fran-1,3-di 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-carboxynorbornane-2: 3,5: 6-dianhydride, 4 , 9-dioxatricyclo "5.3.1.0 ^2,6 " undecane-3,5,8,10-tetraone, and compounds represented by the following formula (5).

Among the other tetracarboxylic dianhydrides other than the alicyclic tetracarboxylic dianhydrides, for example, butanetetracarboxylic dianhydride, pyromellitic dianhydride, 3,3 ′, 4, 4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenylsulfone tetracarboxylic dianhydride, 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride, 1, 4,5,8-naphthalenetetracarboxylic dianhydride and the like.
Among these tetracarboxylic dianhydrides, the alicyclic tetracarboxylic dianhydride is preferably 50 mol% or more based on the total tetracarboxylic dianhydrides.

<Diamine>
Examples of the diamine used for the synthesis of the polyamic acid other than the specific polyamic acid polymer include p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylethane, and 4,4. '-Diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 4,4'- Diaminobenzanilide, 4,4′-diaminodiphenyl ether, 1,5-diaminonaphthalene, 3,3-dimethyl-4,4′-diaminobiphenyl, 5-amino-1- (4′-aminophenyl) -1,3 , 3-Trimethylindane, 6-amino-1- (4′-aminophenyl) -1,3,3-trimethylinda , 3,4′-diaminodiphenyl ether, 3,3′-diaminobenzophenone, 3,4′-diaminobenzophenone, 4,4′-diaminobenzophenone, 2,2-bis [4- (4-aminophenoxy) phenyl] Propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) ) Phenyl] sulfone, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 9,9-bis ( 4-aminophenyl) -10-hydroanthracene, 2,7-diaminofluorene, 9,9-dimethyl-2,7-diaminofluore 9,9-bis (4-aminophenyl) fluorene, 4,4′-methylene-bis (2-chloroaniline), 2,2 ′, 5,5′-tetrachloro-4,4′-diaminobiphenyl 2,2′-dichloro-4,4′-diamino-5,5′-dimethoxybiphenyl, 3,3′-dimethoxy-4,4′-diaminobiphenyl, 1,4,4 ′-(p-phenyleneisopropyl Ridene) bisaniline, 4,4 ′-(m-phenyleneisopropylidene) bisaniline, 2,2′-bis [4- (4-amino-2-trifluoromethylphenoxy) phenyl] hexafluoropropane, 4,4′- Aromatic diamino such as diamino-2,2′-bis (trifluoromethyl) biphenyl, 4,4′-bis [(4-amino-2-trifluoromethyl) phenoxy] -octafluorobiphenyl ;
1,1-metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, 4,4-diaminoheptamethylenediamine, 1 , 4-diaminocyclohexane, isophoronediamine, tetrahydrodicyclopentadienylenediamine, hexahydro-4,7-methanoindanylene methylenediamine, tricyclo [6.2.1.0 ^2,7 ] -undecylenedimethyldiamine, 4 Aliphatic and cycloaliphatic diamines such as 1,4′-methylenebis (cyclohexylamine), 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane;
2,3-diaminopyridine, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 5,6-diamino-2,3-dicyanopyrazine, 5,6-diamino-2,4 -Dihydroxypyrimidine, 2,4-diamino-6-dimethylamino-1,3,5-triazine, 1,4-bis (3-aminopropyl) piperazine, 2,4-diamino-6-isopropoxy-1,3 , 5-triazine, 2,4-diamino-6-methoxy-1,3,5-triazine, 2,4-diamino-6-phenyl-1,3,5-triazine, 2,4-diamino-6-methyl -S-triazine, 2,4-diamino-1,3,5-triazine, 4,6-diamino-2-vinyl-s-triazine, 2,4-diamino-5-phenylthiazole, 2,6- Aminopurine, 5,6-diamino-1,3-dimethyluracil, 3,5-diamino-1,2,4-triazole, 6,9-diamino-2-ethoxyacridine lactate, 3,8-diamino-6 Phenylphenanthridine, 1,4-diaminopiperazine, 3,6-diaminoacridine, bis (4-aminophenyl) phenylamine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, N-ethyl -3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N, N'-di (4-aminophenyl) -benzidine, N, N'-di (4-aminophenyl) -N, N A diamine having two primary amino groups and a nitrogen atom other than the primary amino group in the molecule, such as'-dimethyl-benzidine; Such as diamino organosiloxanes being. These diamines can be used alone or in combination of two or more.

(In the formula, R ⁵ represents a hydrocarbon group having 1 to 12 carbon atoms, and a plurality of R ⁵ may be the same or different, p is an integer of 1 to 3, and q is 1 to 20) Is an integer.)

  Of these, p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl sulfide, 2,2′-dimethyl-4,4′-diaminobiphenyl, 1,5-diaminonaphthalene, 2,7 -Diaminofluorene, 9,9-dimethyl-2,7-diaminofluorene, 4,4'-diaminodiphenyl ether, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 9,9-bis (4 -Aminophenyl) fluorene, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4 '-(p-pheny Range isopropylidene) bisaniline, 4,4 ′-(m-phenylenediisopropylidene) bisaniline, 1 4-cyclohexanediamine, 4,4′-methylenebis (cyclohexylamine), 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-amino) Phenoxy) biphenyl, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminoacridine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N, N′-di (4-aminophenyl) -benzidine and the like are preferable.

In the case where the liquid crystal aligning agent of the present invention has pretilt angle expression, a part or all of Q ¹ and Q ^{2 in} the above formulas (I-1) and (I-2) are represented by the following formula (Q-1). And at least one group represented by the following formula (Q-2). That is, a diamine having a group represented by the following formula (Q-1) or the following formula (Q-2) (hereinafter also referred to as “specific diamine”) is used. These may be used alone or in combination of two or more.

(In the formula, X is a single bond, —O—, —CO—, —COO—, —OCO—, —NHCO—, —CONH—, —S— or an arylene group, and R ⁶ has 10 carbon atoms. An alkyl group of -20, a monovalent organic group having an alicyclic skeleton having 4 to 40 carbon atoms, or a monovalent organic group having a fluorine atom having 6 to 20 carbon atoms.)

(In the formula, X is a single bond, —O—, —CO—, —COO—, —OCO—, —NHCO—, —CONH—, —S— or an arylene group, and R ⁷ has 4 carbon atoms. It is a divalent organic group having an alicyclic skeleton of ˜40.)

In the above formula (Q-1), examples of the alkyl group having 10 to 20 carbon atoms represented by R ⁶ include n-decyl group, n-dodecyl group, n-pentadecyl group, n-hexadecyl group, n- An octadecyl group, n-eicosyl group, etc. are mentioned. Examples of the organic group having an alicyclic skeleton having 4 to 40 carbon atoms represented by R ⁶ in the above formula (Q-1) and R ⁷ in the above formula (Q-2) include cyclobutane and cyclopentane. Groups having an alicyclic skeleton derived from cycloalkane such as cyclohexane and cyclodecane; groups having a steroid skeleton such as cholesterol and cholestanol; groups having a bridged alicyclic skeleton such as norbornene and adamantane. Among these, a group having a steroid skeleton is particularly preferable. The organic group having an alicyclic skeleton may be a group substituted with a halogen atom, preferably a fluorine atom, or a fluoroalkyl group, preferably a trifluoromethyl group.
Furthermore, examples of the group having 6 to 20 carbon atoms represented by R ⁶ in the formula (Q-1) include carbon atoms such as an n-hexyl group, an n-octyl group, and an n-decyl group. A linear alkyl group having 6 or more; an alicyclic hydrocarbon group having 6 or more carbon atoms such as a cyclohexyl group or a cyclooctyl group; an organic group such as an aromatic hydrocarbon group having 6 or more carbon atoms such as a phenyl group or a biphenyl group And a group in which part or all of the hydrogen atoms are substituted with a fluoroalkyl group such as a fluorine atom or a trifluoromethyl group.

  X in the formula (Q-1) and the formula (Q-2) is a single bond, -O-, -CO-, -COO-, -OCO-, -NHCO-, -CONH-, -S. -Or an arylene group, and examples of the arylene group include a phenylene group, a tolylene group, a biphenylene group, and a naphthylene group. Of these, groups represented by —O—, —COO—, and —OCO— are particularly preferable. Specific examples of the diamine having the group represented by the formula (Q-1) include dodecanoxy-2,4-diaminobenzene, pentadecanoxy-2,4-diaminobenzene, hexadecanoxy-2,4-diaminobenzene, octadecanoxy- Preferable examples include 2,4-diaminobenzene and compounds represented by the following formulas (9) to (13).

  Specific examples of the diamine having a group represented by the formula (Q-2) include diamines represented by the following formulas (14) to (16).

  Of these, particularly preferred are compounds represented by the above formulas (9), (11), (13) and (14).

  The use ratio of the specific diamine with respect to the total amount of diamine varies depending on the size of the pretilt angle to be expressed. 5 to 100 mol% is preferable.

<Synthesis of polyamic acid>
The proportion of tetracarboxylic dianhydride and diamine used in the synthesis reaction of polyamic acid (including specific polyamic acid polymer) is 1 eq of amino group of diamine, and the acid anhydride of tetracarboxylic dianhydride. A ratio of 0.2 to 2 equivalents of the group is preferable, and a ratio of 0.3 to 1.2 equivalents is more preferable.
The polyamic acid synthesis reaction is preferably performed in an organic solvent under a temperature condition of −20 ° C. to 150 ° C., more preferably 0 to 100 ° C.

  Here, the organic solvent is not particularly limited as long as it can dissolve the synthesized polyamic acid. For example, 1-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, 3- Amide solvents such as butoxy-N, N-dimethylpropanamide, 3-methoxy-N, N-dimethylpropanamide, 3-hexyloxy-N, N-dimethylpropanamide, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea And aprotic polar solvents such as hexamethylphosphotriamide; and phenolic solvents such as m-cresol, xylenol, phenol, and halogenated phenol. The amount of organic solvent used (α) is usually such that the total amount (β) of tetracarboxylic dianhydride and diamine compound is 0.1 to 30% by weight based on the total amount (α + β) of the reaction solution. It is preferable that the amount is small.

In addition, the said organic solvent can use together the alcohol, ketone, ester, ether, halogenated hydrocarbon, hydrocarbon, etc. which are poor solvents of a polyamic acid in the range in which the polyamic acid to produce | generate does not precipitate. Specific examples of such poor solvents include, for example, methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol. , Ethylene glycol monomethyl ether, ethyl lactate, butyl lactate, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, diethyl oxalate, malon Acid diethyl, diethyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i Propyl ether, ethylene glycol-n-butyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, tetrahydrofuran, dichloromethane 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene, hexane, heptane, octane, benzene, toluene, xylene, isoamylpropionate, isoamylisobutyrate, diisopentyl A Or the like can be mentioned Le.
As described above, a reaction solution obtained by dissolving polyamic acid is obtained. Then, the reaction solution is poured into a large amount of poor solvent to obtain a precipitate, and the precipitate is dried under reduced pressure, or the reaction solution is distilled off under reduced pressure with an evaporator to obtain a polyamic acid. The polyamic acid can be purified by dissolving the polyamic acid again in an organic solvent and then precipitating with a poor solvent once or several times.

<Dehydration ring closure reaction>
The polyimide constituting the liquid crystal aligning agent of the present invention can be synthesized by dehydrating and ring-closing some or all of the polyamic acid. In the polyimide used in the present invention, the ratio of repeating units having an imide ring in all repeating units (hereinafter also referred to as “imidation ratio”) is 40 mol% or more, preferably 50 mol% or more. By using a polymer having an imidization ratio of 40 mol% or more, a liquid crystal aligning agent capable of forming a liquid crystal alignment film having a short afterimage erasing time can be obtained. The imidization rate can be determined by the following method.

Method for measuring imidation rate of imidized polymer After imidized polymer was dried under reduced pressure at room temperature, it was dissolved in deuterated dimethyl sulfoxide, and ¹ H-NMR was measured at room temperature using tetramethylsilane as a reference substance. It can obtain | require by the type | formula shown by (ii).
Imidation ratio (%) = (1-A ¹ / A ² × α) × 100 ------ (ii)
A ¹ : NH group proton-derived peak area (10 ppm)
A ² : Peak area derived from other protons α: Number ratio of other protons to one proton of NH group in polymer precursor (polyamic acid)

The polyamic acid is dehydrated and closed by (i) a method of heating the polyamic acid, or (ii) dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydrating ring-closing catalyst to this solution, and heating as necessary. By the method.
The reaction temperature in the method of heating the polyamic acid (i) is preferably 50 to 200 ° C, more preferably 60 to 170 ° C. When the reaction temperature is less than 50 ° C., the dehydration ring-closing reaction does not proceed sufficiently, and when the reaction temperature exceeds 200 ° C., the molecular weight of the imidized polymer obtained may decrease.

  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 amount of the dehydrating agent used depends on the desired imidization ratio, but is preferably 0.01 to 20 mol per 1 mol of the polyamic acid repeating unit. Moreover, as a dehydration ring closure catalyst, tertiary amines, such as a pyridine, a collidine, a lutidine, a triethylamine, can be used, for example. However, it is not limited to these. The amount of the dehydration ring closure catalyst used is preferably 0.01 to 10 moles per mole of the dehydrating agent used. The imidation rate can be increased as the amount of the above dehydrating agent and dehydrating ring-closing agent increases. In addition, as an organic solvent used for dehydration ring closure reaction, the organic solvent illustrated as what is used for the synthesis | combination of a polyamic acid can be mentioned. And reaction temperature of dehydration ring closure reaction becomes like this. Preferably it is 0-180 degreeC, More preferably, it is 10-150 degreeC. Moreover, the obtained specific polymer can be refine | purified by performing operation similar to the purification method of a polyamic acid with respect to the reaction solution obtained in this way.

<End-modified polymer>
The polyamic acid and polyimide used in the present invention may be of a terminal modified type with a controlled molecular weight. By using this terminal-modified polymer, the coating characteristics of the liquid crystal aligning agent can be improved without impairing the effects of the present invention. Such a terminal-modified polymer can be synthesized by adding an acid monoanhydride, a monoamine compound, a monoisocyanate compound or the like to the reaction system when synthesizing a polyamic acid. Here, as the acid monoanhydride, for example, maleic anhydride, phthalic anhydride, itaconic anhydride, n-decyl succinic anhydride, n-dodecyl succinic anhydride, n-tetradecyl succinic anhydride , N-hexadecyl succinic anhydride and the like. Examples of monoamine compounds include aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, and n-undecylamine. N-dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecylamine, n-octadecylamine, n-eicosylamine, etc. Can do. Examples of the monoisocyanate compound include phenyl isocyanate and naphthyl isocyanate.

Solution viscosity The polymer used in the alignment agent of the present invention preferably has a viscosity of 20 to 800 mPa · s, and a viscosity of 30 to 500 mPa · s when a 10% by weight solution is obtained. It is more preferable that
The solution viscosity (mPa · s) of the polymer was measured at 25 ° C. using an E-type rotational viscometer for a solution diluted to a predetermined solid content concentration using a predetermined solvent.

[Liquid crystal aligning agent]
In the liquid crystal aligning agent of the present invention, the specific compound or the specific polyamic acid polymer is preferably constituted by dissolving the above polymer and other components optionally added usually in an organic solvent.
The liquid crystal aligning agent of the present invention may contain an epoxy compound and a functional silane-containing compound from the viewpoint of improving the adhesion to the substrate surface within a range not impairing the target physical properties. Examples of such epoxy compounds include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, and 1,6-hexane. Diol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, N, N, N ′, N′— Tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ′, N′-tetraglycidyl-4,4′-dia Nodiphenylmethane, 3- (N-allyl-N-glycidyl) aminopropyltrimethoxysilane, 3- (N, N-diglycidyl) aminopropyltrimethoxysilane, N, N, -diglycidyl-benzylamine, N, N-diglycidyl-amino And methylcyclohexane. Examples of the epoxy group-containing 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, 1, 6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentylglycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, N, N, N ′, N′-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ′, N′-tetraglycidyl-4, 4 ′ Diaminodiphenylmethane, N, N, - diglycidyl - benzylamine, N, N-diglycidyl - such as aminomethyl cyclohexane may be mentioned as preferred. The blending ratio of these epoxy group-containing 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 polymer.

Examples of such functional silane-containing compounds include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, and N- (2-aminoethyl). -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-amino Propyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl- , 4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N -Bis (oxyethylene) -3-aminopropyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, etc. can be mentioned. The compounding ratio of the functional silane-containing compound is preferably 4 parts by weight or less with respect to 100 parts by weight of the polymer.

  Examples of the organic solvent constituting the liquid crystal aligning agent of the present invention include 1-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N, N-dimethylformamide, N, N-dimethylacetamide, 4-hydroxy- 4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether , Ethylene glycol-i-propyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl Ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, 3-butoxy-N, N-dimethylpropanamide, 3-methoxy-N, N-dimethylpropanamide, Examples include 3-hexyloxy-N, N-dimethylpropanamide, isoamylpropionate, isoamylisobutyrate, diisopentyl ether, and the like. Of these, 3-butoxy-N, N-dimethylpropanamide, 3-methoxy-N, N-dimethylpropanamide, and 3-hexyloxy-N, N-dimethylpropanamide exhibit particularly good printability. preferable.

  The solid concentration in the liquid crystal aligning agent of the present invention is selected in consideration of viscosity, volatility, etc., but is preferably in the range of 1 to 10% by weight. That is, the liquid crystal aligning agent of the present invention is applied to the substrate surface to form a coating film that becomes a liquid crystal alignment film. When the solid content concentration is less than 1% by weight, the coating film thickness is When the solid content concentration exceeds 10% by weight, the film thickness of the coating film becomes excessive and a good liquid crystal alignment film cannot be obtained. In addition, the viscosity of the liquid crystal aligning agent increases, resulting in poor coating characteristics.

The particularly preferable solid content concentration range varies depending on the method used when the liquid crystal aligning agent is applied to the substrate. For example, when the spinner method is used, the range of 1.5 to 4.5% by weight is particularly preferable. In the case of the printing method, it is particularly preferable that the solid content concentration is in the range of 3 to 9% by weight, and thereby the solution viscosity is in the range of 12 to 50 mPa · s. In the case of the ink jet method, it is particularly preferable that the solid content concentration is in the range of 1 to 5% by weight, and thereby the solution viscosity is in the range of 3 to 15 mPa · s.
The temperature at the time of preparing the liquid crystal aligning agent of this invention becomes like this. Preferably it is 0 to 200 degreeC, More preferably, it is 20 to 60 degreeC.

<Liquid crystal display element>
The liquid crystal display element obtained using the liquid crystal aligning agent of this invention can be manufactured, for example with the following method.
(1) The liquid crystal aligning agent of the present invention is applied to one surface of a substrate provided with a patterned transparent conductive film by an offset printing method, a spin coating method, or an ink jet printing method, and then the coated surface is heated. To form a coating film. Here, as the substrate, for example, glass such as float glass or soda glass; a transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, alicyclic polyolefin, or the like 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. Can be used. For patterning these transparent conductive films, a photo-etching method or a method using a mask in advance is 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-containing compound, a functional titanium-containing compound, or the like is previously applied to the surface of the substrate. You can also After applying 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. Thereafter, a baking (post-baking) step is performed for the purpose of completely removing the solvent and heat imidizing the polyamic acid. The firing (post-bake) temperature is preferably 80 to 300 ° C, more preferably 120 to 250 ° C. The liquid crystal aligning agent of the present invention containing a polyamic acid forms a coating film that becomes an alignment film by removing the organic solvent after coating. It can also be a membrane. The film thickness of the formed coating film is preferably 0.001-1 μm, more preferably 0.005-0.5 μm.

(2) A rubbing process is performed in which the formed coating film surface is rubbed in a certain direction with a roll wound with a cloth made of a fiber such as nylon, rayon, or cotton. Thereby, the orientation ability of a liquid crystal molecule is provided to a coating film, and it becomes a liquid crystal aligning film. Further, by partially irradiating the liquid crystal alignment film formed of the liquid crystal alignment agent of the present invention with ultraviolet rays as disclosed in, for example, JP-A-6-222366 and JP-A-6-281937. A resist film is partially formed on the surface of the liquid crystal alignment film that has been subjected to a treatment for changing the pretilt angle or a rubbing treatment as disclosed in JP-A-5-107544, which is different from the previous rubbing treatment. The visibility characteristics of the liquid crystal display element can be improved by removing the resist film after performing the rubbing treatment in the direction and changing the liquid crystal alignment ability of the liquid crystal alignment film.

(3) Two substrates on which the liquid crystal alignment film is formed as described above are manufactured, and the two substrates are separated by a gap (cell gap) so that the rubbing directions in the respective liquid crystal alignment films are orthogonal or antiparallel. ), And the periphery of the two substrates are bonded together using a sealant, and liquid crystal is injected and filled in the cell gap defined by the substrate surface and the sealant, and the injection hole is sealed. A liquid crystal cell is constructed. A polarizing plate is disposed on the outer surface of the liquid crystal cell, that is, on the other surface side of each substrate constituting the liquid crystal cell, and the polarization direction thereof coincides with or is orthogonal to the rubbing direction of the liquid crystal alignment film formed on one surface of the substrate. A liquid crystal display element is obtained by pasting together.

  Here, as the sealing agent, for example, an epoxy resin containing a curing agent and aluminum oxide spheres as a spacer can be used.

Examples of the liquid crystal include nematic liquid crystal and smectic liquid crystal. Among them, nematic liquid crystal is preferable. For example, Schiff base liquid crystal, azoxy liquid crystal, biphenyl liquid crystal, phenyl cyclohexane liquid crystal, ester liquid crystal, terphenyl liquid crystal. Liquid crystals, biphenylcyclohexane liquid crystals, pyrimidine liquid crystals, dioxane liquid crystals, bicyclooctane liquid crystals, cubane liquid crystals, and the like can be used. Further, for these liquid crystals, for example, cholesteric liquid crystals such as cholestyl chloride, cholesteryl nonate, cholesteryl carbonate, and chiral agents such as those sold under the trade names “C-15” and “CB-15” (manufactured by Merck). Etc. can also be used. Furthermore, a ferroelectric liquid crystal such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate can also be used.
Further, 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 an H film that absorbs iodine while sandwiching and stretching polyvinyl alcohol 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.
[Printability evaluation]
A 127 mm (D) × 127 mm (W) × 1.1 mm (H) glass substrate with an ITO film formed on the entire surface of one side is prepared, and a liquid crystal alignment film coating printer (Nissha Printing Co., Ltd.) is prepared on this glass substrate. The liquid crystal aligning agent obtained in the above experiment was filtered with a microfilter having a pore diameter of 0.2 μm using an Angstromer S-40L) and then applied to the transparent electrode surface. It dried with the hotplate close contact type preliminary dryer set to 80 degreeC, and baked for 60 minutes at 200 degreeC, and formed the liquid crystal aligning film on the glass substrate with an ITO film | membrane. The unevenness of the obtained alignment film was visually evaluated according to the following criteria.
○: Unevenness is not observed at all.
Δ: Some unevenness is observed.
X: Unevenness is clearly observed.

[Voltage holding ratio]
A voltage of 5 V at 60 ° C. was applied to the liquid crystal display element at an application time of 60 microseconds with a span of 167 milliseconds, and then the voltage holding ratio after 167 milliseconds from the application release was measured. The measuring apparatus used was VHR-1 manufactured by Toyo Corporation.

[Burn-in test]
A cell having an ITO electrode as shown in FIG. 1 was produced. A DC voltage of 6.0 V was applied to the electrode A, and a DC voltage of 0.5 V was applied to the electrode B at room temperature for 24 hours. After releasing the stress, a DC voltage of 0.1 to 5.0 V was applied to the electrodes A and B in increments of 0.1 V. The image sticking characteristics were determined based on the luminance difference between the electrodes A and B at each voltage. When the luminance difference was large, it was judged that the image sticking characteristic was bad.
○: Little difference in luminance is known.
Δ: Some luminance difference exists.

<Synthesis 1 of specific compound>

  The nickel catalyst used in this reaction is easily deactivated by reaction with oxygen and water vapor in the atmosphere. Therefore, the solvent and reagent used for the reaction were used after removing impurities by distillation and recrystallization treatment in advance. The polymerization reaction was performed in a nitrogen atmosphere.

The polymerization reaction was carried out according to the literature method (T. Kanbara, J. Polym. Sci. Part-A, Polym. Chem., 38, 4194 (2000)). In a four-necked flask purged with nitrogen gas, 4,4′-dichlorobiphenyl (1 mmol), benzidine (1 mmol), and 15 ml of toluene were added and stirred for several minutes. Then, 288 mg (3 mmol) of sodium-tert-butoxide, bis ( 28 mg (0.1 mmol) of 1,5-cyclooctadiene) nickel (0) (Ni (cod) ₂ ) and 166 mg (0.3 mmol) of 1,1′-bis (diphenylphosphino) ferrocene (DPPF) at room temperature Added below. The reaction was heated to 60 ° C. with stirring under a nitrogen atmosphere to initiate the reaction. After reacting at 60 ° C. for 24 hours, a very small amount of benzidine (0.05 mmol) was added, and the ends of the polymer were sealed with benzidine to terminate the polymerization. After cooling to room temperature, the reaction solution is poured into 200 ml of a mixture of aqueous ammonia and methanol, the resulting precipitate is filtered off, the recovered precipitate is further washed with methanol and ether, and the specific compound A-1 Got.

<Synthesis 2 of specific compound>

The specific compound A-2 includes a plurality of structures as described above.
A THF solution of the specific compound A-1 and an excess amount of sodium amide were mixed in a three-necked flask. The solution was heated to reflux for 2 hours, the reaction solution was cooled, and an excess amount of epibromohydrin was added dropwise. The mixture was heated to 80 ° C. and subsequently stirred for 6 hours. The reaction solution was filtered, and the filtrate was separated and washed in the order of chloroform / 10% aqueous hydrochloric acid and saturated brine. The organic layer was dried over anhydrous magnesium sulfate and the solvent was distilled off. Specific compound A-2 was obtained by performing methanol reprecipitation of the residue.

Polyimide synthesis example 1
2,3,5-tricarboxycyclopentyl acetic acid dianhydride 112 g (0.50 mol) and 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro) as tetracarboxylic dianhydride -2,5-dioxo-3-furanyl) naphtho [1,2-c] furan-1,3-dione 157 g (0.50 mol), p-phenylenediamine 96 g (0.89 mol) as the diamine compound, 3 , 3 ′-(tetramethyldisiloxane-1,3-diyl) bis (propylamine) 25 g (0.10 mol) and 3,6-bis (4-aminobenzoyloxy) cholestane 13 g (0.020 mol) Then, 8.1 g (0.030 mol) of n-octadecylamine as a monoamine was dissolved in 960 g of N-methyl-2-pyrrolidone and reacted at 60 ° C. for 6 hours. It was. A small amount of the resulting polyamic acid solution was taken, NMP was added, and the viscosity was measured with a solution having a solid content concentration of 10% by weight. As a result, it was 60 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 imidization reaction, the solvent in the system was replaced with new γ-butyrolactone (the pyridine and acetic anhydride used for the imidization reaction were removed from the system in this operation), and the solid content concentration was 15% by weight. About 2,000 g of an imidized polymer (referred to as “polyimide (A-1)”) having a solution viscosity of 70 mPa · s and an imidization ratio of about 95% at a partial concentration of 10% by weight (γ-butyrolactone solution). Got.

Polyimide synthesis example 2
224 g (1.0 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride, 108 g (1.0 mol) of p-phenylenediamine as a diamine compound, and cholesteryl-3,5- 7.8 g (0.015 mol) of diaminobenzoate was dissolved in 3,039 g of N-methyl-2-pyrrolidone and reacted at 60 ° C. for 6 hours to obtain a polyamic acid solution having a solution viscosity of about 260 mPa · s. Next, 2,700 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 396 g of pyridine and 306 g of acetic anhydride were added, and dehydration ring closure was performed at 110 ° C. for 4 hours. After the imidation reaction, the solvent in the system was replaced with new γ-butyrolactone (the pyridine and acetic anhydride used in the imidation reaction were removed from the system in this operation), and the solid content concentration was about 9.0 wt. %, A solid content concentration of 10% by weight (γ-butyrolactone solution), an imidized polymer having a solution viscosity of 250 mPa · s and an imidization ratio of about 51% (hereinafter referred to as “imidized polymer (A-2)”). ) About 3,000 g of a solution was obtained.

Polyamic acid synthesis example 1
196 g (1.0 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride as tetracarboxylic dianhydride and 212 g (1 of 2,2′-dimethyl-4,4′-diaminobiphenyl as diamine compound) 0.0 mol) was dissolved in N-methyl-2-pyrrolidone (370 g) and γ-butyrolactone (3,300 g) and reacted at 40 ° C. for 3 hours, and a solution having a viscosity of 160 mPa · s (hereinafter referred to as “polyamic acid (I-1 About 3,700 g of a solution was obtained.

Polyamic acid synthesis example 2
95 g (0.50 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride as tetracarboxylic dianhydride, 109 g (0.50 mol) of pyromellitic dianhydride, 2.7 as diamine compound -196 g (1.0 mol) of diaminofluorene was dissolved in 230 g of N-methyl-2-pyrrolidone and 2,060 g of γ-butyrolactone, reacted at 40 ° C for 3 hours, and then 1,350 g of γ-butyrolactone was added. About 3,600 g of a polyamic acid solution having a solid content concentration of 10% by weight and a solution viscosity of 125 mPa · s (referred to as “polyamic acid (I-2)”) was obtained.

Example 1
The polyimide (A-1) obtained in Polyimide Synthesis Example 1 and the polyamic acid (I-1) obtained in Polyamic Acid Synthesis Example 1 are polyimide: polyamic acid = 20: 80 (weight ratio). It was dissolved in a γ-butyrolactone / N-methyl-2-pyrrolidone / butyl cellosolve mixed solvent (weight ratio 71/17/12). To this solution, 2 parts by weight of N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane is added with respect to 100 parts by weight of the polymer. 10 parts by weight was added to 100 parts by weight of the coalesced to prepare a solution having a solid content concentration of 3.5% by weight and a solution having a weight of 6.0% by weight. Each solution was sufficiently stirred and then filtered using a filter having a pore size of 1 μm to prepare the liquid crystal aligning agent of the present invention.
Among the liquid crystal aligning agents, a solution having a solid content concentration of 3.5% by weight is 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 (number of rotations: 2,500 rpm, coating time: 1 minute) and dried at 200 ° C. for 1 hour to form a film having a dry film thickness of 0.08 μm. A rubbing machine having a roll in which a rayon cloth was wound around this film was subjected to a rubbing treatment at a roll rotation speed of 400 rpm, a stage moving speed of 3 cm / second, and a hair foot pushing length of 0.4 mm. The liquid crystal alignment film-coated substrate was subjected to ultrasonic cleaning for 1 minute in ultrapure water and dried in a 100 ° C. clean oven for 10 minutes. Next, after applying an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm to the outer edges of the pair of transparent electrodes / transparent electrode substrates having the liquid crystal alignment film of the liquid crystal alignment film coated substrate, the liquid crystal alignment film The adhesive was cured by overlapping and pressing so that the surfaces were opposed. Next, a nematic liquid crystal (MLC-6221, manufactured by Merck & Co., Inc.) is filled between the substrates through the liquid crystal injection port, and then the liquid crystal injection port is sealed with an acrylic photo-curing adhesive, and polarizing plates are formed on both sides of the substrate. Were bonded together to produce a TN liquid crystal display element. The voltage holding ratio evaluation and burn-in evaluation of the obtained liquid crystal display element were performed according to the method described above.
Moreover, printability evaluation was performed according to the method described above using a solution having a solid content concentration of 6.0% by weight.

Examples 2-4
The same procedure as in Example 1 was performed except that the polyimide, polyamic acid, and the specific compound were those shown in Table 1.

Example 5
The polyimide (A-2) obtained in Polyimide Synthesis Example 2 was dissolved in an N-methyl-2-pyrrolidone / butyl cellosolve mixed solvent (weight ratio 50/50), and N, N, N ′, N′-tetra 2 parts by weight of glycidyl-4,4′-diaminodiphenylmethane is added to 100 parts by weight of the polymer, 10 parts by weight of the specific compound A-1 is added to 100 parts by weight of the polymer, and the solid content concentration is 3.5% by weight. And a 6.0 wt% solution. Each solution was sufficiently stirred and then filtered using a filter having a pore size of 1 μm to prepare the liquid crystal aligning agent of the present invention. The method for producing the liquid crystal display element, the method for evaluating the liquid crystal display element, and the method for evaluating the orientation agent printability were performed in the same manner as in Example 1.

Example 6
The same procedure as in Example 5 was performed, except that the compounds shown in Table 1 were used as the specific compound.

Comparative Examples 1-2
The polyimide and polyamic acid were the same as those used in Example 1 except that the materials shown in Table 1 were used and the specific compound was not added.

Comparative Example 3
The same procedure as in Example 5 was performed except that the specific compound was not added.

Comparative Examples 4-5
The polyimide and polyamic acid were the same as those used in Example 1 except that the compounds shown in Table 1 were used and a compound (compound X) having the following structure was used instead of the specific compound. Compound X was synthesized according to the method described in JP-A No. 2000-44683.

Comparative Example 6
The same procedure as in Example 5 was performed except that Compound X was added instead of the specific compound.

Comparative Examples 7-8
The polyimide and polyamic acid were the same as those used in Example 1, except that the compounds shown in Table 1 were used and a compound (Compound Y) having the following structure was used instead of the specific compound. Compound Y was synthesized according to the method described in WO2002 / 100949. The molecular weight was Mn = 15,000 and Mw = 30,000.

Comparative Example 9
The same procedure as in Example 5 was performed except that Compound Y was added instead of the specific compound.

Cell with ITO electrode created for evaluation of burn-in test.

Claims (7)

The following formula (I):
(Wherein R _{1 to} R ₈ are each independently a hydrogen atom, an alkyl group or an alkoxy group, and R _{9 to} R ₁₂ are each independently a hydrogen atom, an aromatic group, an aliphatic group or An aliphatic group substituted with an epoxy group, A is an aliphatic group substituted with a hydrogen atom, an aliphatic group or an epoxy group, and n is an integer of 1 to 100.)
The liquid crystal aligning agent characterized by containing the compound represented by these. In formula (I), R _{1 to} R ₈ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms, and R _{9 to} R ₁₂ are all hydrogen. The liquid crystal aligning agent according to claim 1, which is an atom, A is a hydrogen atom, and n is an integer of 1 to 100. In formula (I), R _{1 to} R ₈ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, and R ₉ and R ₁₁ are aromatic. 2. The liquid crystal aligning agent according to claim 1, wherein R ₁₀ and R ₁₂ are a hydrogen atom or an aliphatic group, A is a hydrogen atom or an aliphatic group, and n is an integer of 1 to 100. In formula (I), R _{1 to} R ₈ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, and R ₉ and R ₁₁ are aromatic groups. R ₁₀ and R ₁₂ are an aliphatic group substituted with a hydrogen atom or an epoxy group, A is an aliphatic group substituted with a hydrogen atom or an epoxy group, and n is an integer of 1 to 100 The liquid crystal aligning agent of Claim 1. A liquid crystal aligning agent comprising a polyamic acid polymer obtained by a reaction between the compound according to claim 2 and tetracarboxylic dianhydride. The polymer further contains at least one polymer selected from the group consisting of a polyamic acid composed of a repeating unit represented by the following formula (I-1) and a polyimide composed of a repeating unit represented by the following formula (I-2). The liquid crystal aligning agent in any one of 1-5.
(Where P ¹ is a tetravalent organic group and Q ¹ is a divalent organic group)
(Where P ² is a tetravalent organic group and Q ² is a divalent organic group) A liquid crystal display element comprising a liquid crystal alignment film obtained by using the liquid crystal aligning agent according to claim 1.