TWI434111B - Liquid crystal aligning agent and liquid crystal display element - Google Patents

Description

Liquid crystal alignment agent and liquid crystal display element

The present invention relates to a liquid crystal alignment agent and a liquid crystal display element. In particular, the liquid crystal alignment agent of the liquid crystal alignment film which is excellent in the coating property in the inkjet coating method, and which is excellent in liquid crystal alignment performance, and the liquid crystal display element which is excellent in display characteristics and reliability.

Conventionally, as a liquid crystal display element, a liquid crystal alignment film composed of polyacrylic acid, polyimine or the like is formed on a surface of a substrate provided with a transparent conductive film such as ITO (indium oxide-tin oxide) as a liquid crystal display. A sandwich structure in which two sheets are opposed to each other to form a nematic liquid crystal layer having dielectric anisotropy in a gap therebetween, and a long axis of the liquid crystal molecules is continuously twisted 90 ∘ from one substrate to the other substrate. A TN type liquid crystal display element of a so-called TN (torsional nematic) type liquid crystal cell. Further, an STN (Super Torsion Nematic) liquid crystal display element having a higher contrast ratio than a TN liquid crystal display element and having a small viewing angle dependency has been developed. The STN type liquid crystal display element is used as a liquid crystal for a liquid-based agent doped with an optically active substance in a nematic liquid crystal, and is produced by a state in which the long axis of the liquid crystal molecules is 180 ∘ continuously twisted between the substrates. Birefringence effect.

In recent years, it has been proposed to use a horizontal electric field type liquid crystal display element in which two electrodes for driving a liquid crystal are arranged in a comb shape on a single-sided substrate, and an electric field is generated in parallel with the substrate surface to control liquid crystal molecules. The component is generally called an in-plane switching type (In-Plane Switching type, IPS type), and the viewing angle is known. Excellent and wide. In particular, when the IPS type element is used in combination with the optical compensation film, the viewing angle characteristic can be further improved, and the stepless inversion or the color tone change can be obtained, and the feature of the wide viewing angle which is comparable to the Brown tube can be obtained.

In addition, there is a proposal for a vertical alignment type called MVA (multi-region vertical alignment) or PVA (image vertical alignment) in which liquid crystal molecules having negative dielectric anisotropy are vertically aligned on a substrate. Liquid crystal display element (refer to Japanese Laid-Open Patent Publication No. Hei 11-258605, and "Liquid Crystal", Vol. 3 (No. 2), p. 117 (1999)). The liquid crystal display elements of the vertical alignment type are excellent in viewing angle, contrast, and the like, and do not require rubbing treatment in forming the liquid crystal alignment film, and are excellent in terms of production steps.

However, in recent years, with the popularization of LCD TVs, a large-scale route called "The 7th Generation" has been launched. Also, it is scheduled to establish a larger "8th Generation" route. As an advantage of using a large-scale route to increase the size of the substrate, the engineering time for disassembling a plurality of panels from one substrate can be reduced, and the cost can be reduced, and the liquid crystal display element itself can be enlarged. Conversely, the disadvantage of the enlargement of the substrate is exemplified by the difficulty in ensuring the printing uniformity of the liquid crystal alignment agent over a large area. In particular, when a large-area liquid crystal alignment film is formed by a conventionally used lithographic printing machine, there is a case where the liquid crystal alignment film is defective in printing and the liquid crystal alignment film has poor electrical characteristics.

In order to solve the above problems, it has been considered to use an inkjet coating method in film formation of a liquid crystal alignment film. The advantage of the inkjet coating method is that the liquid crystal alignment agent used in the printing is expected to reduce the amount of the liquid crystal alignment agent because it is substantially equal to the amount of the liquid actually applied, since the printing plate is not used and it is not necessary to exchange or wash. Print Maintenance time such as brushing can reduce labor and cost, and thus can have degrees of freedom corresponding to various panel sizes.

In a large-sized substrate manufactured by a large-scale route, in order to produce a high-yield liquid crystal display element, a liquid crystal alignment agent excellent in printability has been required in the inkjet printing method. Further, in recent years, the demand for improvement in display quality has become more stringent, and in particular, regarding liquid crystal alignment properties and electrical characteristics, a liquid crystal alignment film having higher characteristics than hitherto has been demanded.

The present invention has been made in view of the above problems, and an object thereof is to provide an improvement in product yield in a large-scale route manufacturing step which is excellent in printability in an inkjet coating method, and which can obtain liquid crystal alignment energy, electrical characteristics, and the like. A liquid crystal alignment agent of a liquid crystal alignment film having excellent performance and a liquid crystal display element which exhibits high quality display characteristics and is excellent in reliability.

Other objects and advantages of the present invention will become apparent from the following description.

According to the present invention, first, the above objects and advantages of the present invention can be attained by the following liquid crystal alignment agent comprising a polylysine selected from the group consisting of a reaction of a tetracarboxylic dianhydride with a diamine compound and a dehydration ring closure thereof. At least one polymer and solvent in the group of the obtained polyimine

The solvent contains: (A) a first solvent consisting of a compound represented by the following formula (I): (in the formula (I), each R is independently an alkyl group having 3 to 10 carbon atoms), and (B) a second solvent consisting of at least one selected from the group consisting of N-methyl-2- Pyrrolidone, γ-butyrolactone, 1,3-dimethyl-2-imidazolidinone, N,N-dimethylformamide, and N,N-dimethylacetamide; and (C) A third solvent consisting of at least one selected from the group consisting of butyl cellosolve, diacetone alcohol, propylene carbonate, diethylene glycol diethyl ether, and ethyl 3-ethoxypropionate.

Second, the above objects and advantages of the present invention can be attained by providing a liquid crystal display element having a liquid crystal alignment film obtained by the above liquid crystal alignment agent.

[Best form for implementing the invention]

The invention is described in detail below.

The liquid crystal alignment agent of the present invention contains at least one polymer selected from the group consisting of polylysine obtained by reacting a tetracarboxylic dianhydride with a diamine compound and polyimine obtained by dehydration ring closure, and a solvent.

[tetracarboxylic dianhydride]

The tetracarboxylic dianhydride used for synthesizing the polyamic acid or polyimine contained in the liquid crystal hydrating agent of the present invention is exemplified by a compound represented by the following formula (1): (In the formula (1), R ^{1 is} each independently a hydrogen atom, a chlorine atom or an alkyl group having 1 to 6 carbon atoms)

A compound represented by the following formula (2): (In the formula (2), R ^{2 is} independently an alkyl group having 1 to 6 carbon atoms, n is an integer of 0 to 4), butane tetracarboxylic dianhydride, 1,2,3,4-cyclopentane IV Carboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3',4,4'-dicyclohexanetetracarboxylic dianhydride, 2,3,5-tricarboxyl Cyclopentyl acetic acid dianhydride, 1,2,4-tricarboxycyclopentyl acetic acid dianhydride, bicyclo [2.2.1] heptane-2,3,5,6-tetracarboxylic dianhydride, 3,5,6 - tricarboxy-norbornene-2-acetic acid dianhydride, tetracyclo [4.4.0.1 ^2,5 .1 ^7,10 ] dodecane-3,4,8,9-tetracarboxylic dianhydride, 2,3, 4,5-tetrahydrofuran tetracarboxylic dianhydride, 5-(2,5-dioxotetrahydrofuranyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, bicyclo [2.2. 2]-oct-4-ene-2,3,5,6-tetracarboxylic dianhydride, bicyclo[2.2.2]-oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, Compounds represented by the following formulas (II-1) and (II-2), respectively:

(In the above formula, R ³ and R ⁵ are each a divalent organic group having an aromatic ring, and R ⁴ and R ^{6 are} each a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and a plurality of R ⁴ and R ⁶ are present. Aliphatic or alicyclic tetracarboxylic dianhydrides which may be the same or different); pyromellitic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 3, 3',4,4'-biphenylfluorene tetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3 ',4,4'-diphenyl ether tetracarboxylic dianhydride, 3,3',4,4'-dimethyldiphenylnonane tetracarboxylic dianhydride, 3,3',4,4'-four Phenylnonane tetracarboxylic dianhydride, 1,2,3,4-furan tetracarboxylic dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenyl sulfide dianhydride, 4 , 4'-bis(3,4-dicarboxyphenoxy)diphenylphosphonium dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenylpropane dianhydride, 3,3 ',4,4'-perfluoroisopropylidene dicarboxylic acid dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, bis(decanoic acid) phenylphosphine oxide dianhydride, Ethylene glycol-bis(anhydrous trimellitate), propylene glycol-bis(anhydrous trimellitate), 1,4-butanediol-bis(anhydrous trimellitate), 1,6-hexane Alcohol-bis(anhydrous tricarboxylic acid ester), 1,8-octanediol-double ( Aromatic compounds such as water benzene trimellitate), 2,2-bis(4-hydroxyphenyl)propane-bis(anhydrous benzene trimellitate), and compounds represented by the following formulas (3) to (6) Tetracarboxylic dianhydride, etc.:

Specific examples of the compound represented by the above formula (1) can be exemplified by, for example, 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 1,2-dimethyl-1,2,3,4-cyclobutane. Alkanetetracarboxylic dianhydride, 1,2-diethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutane Alkanetetracarboxylic dianhydride, 1,3-diethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dichloro-1,2,3,4-cyclobutane Tetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, preferably 1,2,3,4-ring Butane tetracarboxylic dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-diethyl-1,2,3,4-ring Butane tetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride or 1,3-diethyl-1,2,3,4-ring Butane tetracarboxylic dianhydride.

Specific examples of the compound represented by the above formula (2) can be exemplified by, for example, 1,3,3a,4,5,9b-hexahydro-5(tetrahydro-2,5-dioxo-3-furanyl)-naphthalene. And [1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-5-methyl-5(tetrahydro-2,5-dioxo -3-furyl)-naphtho[1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-5-ethyl-5 (tetrahydrogen) -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-di Ketone, 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.

These tetracarboxylic dianhydrides may be used alone or in combination of two or more.

Among these, a compound selected from the group consisting of the compound represented by the above formula (1), the compound represented by the above formula (2), pyromellitic dianhydride, and 1,2,4-tricarboxycyclopentyl acetic acid dianhydride are preferably used. 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 1,2,3,4-cyclopentane tetracarboxylic dianhydride and 1,2,4,5-cyclohexanetetracarboxylic dianhydride It is preferred that at least one of the groups (hereinafter referred to as "specific tetracarboxylic dianhydride") is a tetracarboxylic dianhydride.

When the polymer contained in the liquid crystal alignment agent of the present invention is polyamic acid, the tetracarboxylic dianhydride used for the synthesis is preferably contained in an amount of 10 mol% or more based on the total amount of the tetracarboxylic dianhydride. The specific tetracarboxylic dianhydride preferably contains 20 mol% or more, more preferably 40 mol% or more. In this case, an alicyclic tetracarboxylic dianhydride is preferably used as the tetracarboxylic dianhydride other than the specific tetracarboxylic dianhydride.

On the other hand, when the polymer contained in the liquid crystal alignment agent of the present invention is a polyimine, the tetracarboxylic dianhydride used for the synthesis is preferably contained in an amount of 50 relative to the total amount of the tetracarboxylic dianhydride. a specific tetracarboxylic dianhydride of more than 5% by mole, More preferably, it contains more than 70% by mole, and more preferably more than 80% by mole. In this case, an alicyclic tetracarboxylic dianhydride is preferably used as the tetracarboxylic dianhydride other than the specific tetracarboxylic dianhydride.

[diamine compound]

The diamine compound used for synthesizing the polyamic acid or polyimine contained in the liquid crystal alignment agent of the present invention may, for example, be a compound represented by the following formulas (III-1) and (III-2) and other diamine compounds. :

(In the above formula, X ^{1 is} independently a single bond, -O-, -CO-, -COO-, -OCO-, -NHCO-, -CONH-, -S-, methylene, carbon number 2-6 An alkyl group or a phenyl group, and R ⁷ is a monovalent organic group having an alkyl group having 10 to 20 carbon atoms, an alicyclic skeleton having 4 to 40 carbon atoms, or a monovalent organic group having a carbon number of 6 to 20 and having a fluorine atom. The organic group, R ⁸ is a divalent organic group having an alicyclic skeleton having 4 to 40 carbon atoms.

In the above formula (III-1), the alkyl group having 10 to 20 carbon atoms represented by R ⁷ can be exemplified by, for example, n-decyl group, n-dodecyl group, n-pentadecyl group, n-hexadecyl group, and positive ten. Octaalkyl, n-icosyl, and the like. The alicyclic skeleton contained in the monovalent organic group having an alicyclic skeleton having 4 to 40 carbon atoms may, for example, be a fat derived from a cycloalkane such as cyclobutane, cyclopentane, cyclohexane or cyclodecane. Ring skeleton; original borneol, adamantyl, etc. have a bridged ring skeleton; steroid skeleton and the like.

Here, the steroid skeleton is a structure composed of a cyclopentanone hydrogenated phenanthrene nucleus or a skeleton in which one or two or more carbon-carbon bonds are double bonds. The monovalent organic group having a steroid skeleton of R ⁷ is preferably a carbon number of 17 to 40, more preferably a carbon number of 17 to 29. Specific examples of R ⁷ having such a steroid skeleton are exemplified by, for example, cholestyl-3-yl, cholestane-5-en-3-yl, cholestane-24-en-3-yl, cholestane- 5,24-dien-3-yl and the like.

The monovalent organic group having an alicyclic skeleton of R ⁷ may partially or wholly wholly of one of its hydrogen atoms via a halogen atom, preferably a fluorine atom. The monovalent organic group having a fluorine atom of 6 to 20 carbon atoms may, for example, be a linear alkyl group having 6 to 20 carbon atoms such as n-hexyl group, n-octyl group or n-decyl group; carbon such as cyclohexyl group or cyclooctyl group; a 6 to 20 alicyclic hydrocarbon group; a phenyl group, a biphenyl group, or the like, an aromatic hydrocarbon group having 6 to 20 carbon atoms, or the like, wherein a part or all of a hydrogen atom in the organic group is substituted with a fluorine atom or a fluoroalkyl group (wherein The carbon number of R ⁷ includes a carbon of fluoroalkyl group of 20 or less).

X ¹ in the above formula (III-1) is preferably -O-, -CO-, -COO- or -OCO-.

Specific examples of the diamine compound represented by the above formula (III-1) can be exemplified by, for example, dodecyloxy-2,4-diaminobenzene, pentadecyloxy-2,4-diaminobenzene, and hexadecane. Oxy-2,4-diaminobenzene, octadecyloxy-2,4-diaminobenzene, compounds represented by the following formulas (7) to (22):

In the above formula (III-2), the alicyclic skeleton contained in the divalent organic group having an alicyclic skeleton having 4 to 40 carbon atoms represented by R ⁸ can be exemplified by, for example, cyclobutane and cyclopentane. An alicyclic skeleton of a cycloalkane such as an alkane, a cyclohexane or a cyclodecane; a bridged alicyclic skeleton such as a norbornene or an adamantane; a steroid skeleton or the like.

Here, the steroid skeleton is the same as the steroid skeleton in the above R ⁷ . The divalent organic group having a steroid skeleton of R ⁸ is preferably a carbon number of 17 to 40, more preferably a carbon number of 17 to 29. Specific examples of R ⁸ having a steroid skeleton can be exemplified by, for example, cholestane-3,3-diyl, cholestane-3,6-diyl, cholestane-5-ene-3,6-diyl, Cholestane-24-ene-3,6-diyl, cholestane-5,24-diene-3,6-diyl and the like.

The divalent organic group having an alicyclic skeleton of R ⁸ may be partially or wholly a part of all of its hydrogen atoms may be substituted by a halogen atom, preferably by a fluorine atom.

Specific examples of the diamine compound represented by the above formula (III-2) include compounds represented by the following formulas (23) to (27):

The above other diamine compound can be exemplified by, for example, p-phenylenediamine, 2-methyl-1,4-phenylenediamine, 2-ethyl-1,4-phenylenediamine, 2,5-dimethyl-1. , 4-phenylenediamine, 2,5-diethyl-1,4-phenylenediamine, 2,3,5,6-tetramethyl-1,4-phenylenediamine, m-phenylenediamine, 4 , 4'-diaminodiphenylmethane, 4,4'-diaminodiphenylethane, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl Base, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 2,2 '-Diethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-bis(trifluoromethyl)- 4,4'-Diaminobiphenyl, 3,3'-diethyl-4,4'-diaminobiphenyl, 4,4'-diaminobenzimidil, 4,4'- Diaminodiphenyl ether, 1,5-diaminonaphthalene, 2,2'-dimethyl-4,4'-diaminobiphenyl, 5-amino-1-(4'-amino group Phenyl)-1,3,3-trimethylindan, 6-amino-1-(4'-aminophenyl)-1,3,3-trimethylindan, 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-aminobenzene) Oxy)phenyl]hexafluoropropane, 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-aminophenyl)hexafluoropropane, 2,2-bis[4- (4-Aminophenoxy)phenyl]anthracene, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3- Bis(3-aminophenoxy)benzene, 9,9-bis(4-aminophenyl)-10-hydroquinone, 2,7-diaminopurine, 9,9-bis(4-amine Phenyl) fluorene, 4,4'-methylene-bis(2-chloroaniline), 2,2',5,5'-tetrachloro-4,4'-diaminobiphenyl, 2,2'-dichloro-4,4'-diamino-5,5'-dimethoxybiphenyl,3,3'-dimethoxy-4,4'-diaminobiphenyl, 1,4, 4'-(p-phenylphenylisopropylene)diphenylamine, 4,4'-(m-phenylene isopropylidene)diphenylamine, 2,2'-bis[4-(4-amino group -2-trifluoromethylphenoxy)phenyl]hexafluoropropane, 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl, 4,4'-bis[( Aromatic two of 4-amino-2-trifluoromethyl)phenoxy]-octafluorobiphenyl, 4-(4-n-heptylcyclohexyl)phenoxy-2,4-diaminobenzene Amine; 1,3-bis(aminomethyl)benzene, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine , octamethylenediamine, nonamethylenediamine, etc. Aliphatic diamine; 2,3-diaminopyridine, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 5,6-diamino-2 , 3-diaminopiperidine, 5,6-diamino-2,4-dihydroxypyrimidine, 2,4-diamino-6-dimethylamino-1,3,5-triazine, 1 , 4-bis(3-aminopropyl)piperidine, 2,4-diamino-6-isopropoxy-1,3,5-triazine, 2,4-diamino-6- Oxy-1,3,5-triazine, 2,4-diamino-6-phenyl-1,3,5-triazine, 2,4-diamino-6-methyl-s-three Pyrazine, 2,4-diamino-1,3,5-triazine, 4,6-diamino-2-vinyl-s-triazine, 2,4-diamino-5-phenylthiazole , 2,6-diaminopurine, 5,6-diamino-1,3-dimethylurea, 3,5-diamino-1,2,4-triazole, 6,9-diamine Benzyl-2-ethoxy acridine laurate, 3,8-diamino-6-phenylphenanthridine, 1,4-diaminopiperidine, 3,6-diaminoacridine, bis ( a 4-amine-aminophenyl)phenylamine or the like having two primary amine groups in the molecule and a nitrogen atom other than the primary amine group; compounds represented by the following formulas (28) to (30):

(In the above formula, R ^{9 is} independently a hydrocarbon group having 1 to 12 carbon atoms, p is independently an integer of 1 to 3, q is an integer of 1 to 20, y is an integer of 2 to 12, and z is 1 to 5 Integer).

The above other diamine compounds are preferably p-phenylenediamine, 2-methyl-1,4-phenylenediamine, 2-ethyl-1,4-phenylenediamine, 2,5-dimethyl-1, 4-phenylenediamine, 2,5-diethyl-1,4-phenylenediamine, 2,3,5,6-tetramethyl-1,4-phenylenediamine, 4,4'-diamino Diphenylmethane, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 2 , 2'-diethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-diethyl-4, 4'-Diaminobiphenyl, 3,3'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 4,4'-diaminodiphenyl ether, 4,4' -diaminobenzophenone, 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-aminophenyl)hexafluoropropane, 2,6-diaminopyridine or 3,4-diaminopyridine.

These diamine compounds may be used alone or in combination of two or more.

Use of the liquid crystal alignment agent of the invention as a vertical alignment type liquid crystal alignment agent When the diamine compound used for synthesizing the polyamic acid or polyimine contained in the liquid crystal alignment agent is preferably used, the diamine compound selected from the above formula (III-1) and the above formula (III-2) are preferably used. And a diamine compound represented by at least one of the diamine compounds. In this case, the amount of the diamine compound represented by the above formula (III-1) or (III-2) in the total amount of the diamine compound is preferably at least 7 mol%, more preferably at 10 mol%. the above.

[Synthesis of polyglycine]

The polyglycolic acid which the liquid crystal alignment agent of the present invention can contain is obtained by reacting a tetracarboxylic dianhydride with a diamine compound as described above.

The ratio of the tetracarboxylic dianhydride to the diamine to be used in the polyaminic acid synthesis reaction is preferably from 0.2 to 2.0 equivalents based on the amine group of one equivalent of the diamine. More preferably, it is a ratio of 0.8 to 1.2 equivalents. The synthesis reaction of poly-proline is preferably carried out in an organic solvent, preferably at -20 ° C to 150 ° C, more preferably at a temperature of 0 to 100 ° C for 0.5 to 24 hours, more preferably 2 to 10 hours.

The organic solvent to be used herein is not particularly limited as long as the synthetic polyaminic acid can be dissolved, and examples thereof include 1-methyl-2-pyrrolidone and N,N-dimethylacetamide. And aprotic polar solvents such as N,N-dimethylformamide, dimethyl hydrazine, γ-butyrolactone, tetramethyl urea, hexamethylphosphoric acid triamide; m-cresol, dimethyl A phenolic solvent such as a phenol, a phenol or a halogenated phenol. The amount (α) of the organic solvent is preferably such that the total amount (β) of the tetracarboxylic dianhydride and the diamine compound is 0.1 to 30% by mass based on the total amount (α + β) of the reaction solution. .

The organic solvent can be replaced by an alcohol, a ketone, an ester, an ether, or a halogenated compound which is a weak solvent for the polyglycolic acid in a range in which the produced polyaminic acid is not precipitated by using a part of the organic solvent. Hydrocarbons, hydrocarbons, etc.

Specific examples of the weak solvent include, for example, methanol, ethanol, isopropanol, cyclohexanol, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol, propylene glycol, and 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, acetic acid Ester, methyl methoxypropionate, ethyl ethoxypropionate, diethyl oxalate, diethyl malonate, diethyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol Propyl ether, ethylene glycol-1-propyl ether, ethylene glycol n-butyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethyl 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 and the like.

When one part of the organic solvent is substituted with a weak solvent, the amount of the weak solvent used is preferably 50% by weight or less based on the total amount of the organic solvent.

A reaction liquid in which polylysine was dissolved was obtained as described above. The polyaminic acid solution may also be supplied to the dehydration ring-closure reaction of the subsequent step, or the poly-proline contained in the reaction solution may be separately supplied to the dehydration ring-closure reaction, or the isolated polyamine. The acid is purified and supplied to the dehydration ring closure reaction. a method for separating a polyamic acid into a large amount of a weak solvent to obtain a precipitate, and drying the precipitate under reduced pressure, or This was carried out by distilling off the polyaminic acid solution under reduced pressure on a rotary evaporator. Further, the polylysine obtained by dissolving the polylysine thus obtained is dissolved in an organic solvent, followed by precipitation by a weak solvent, or a step of distilling off under reduced pressure in a rotary evaporator. purification.

[Synthesis of Polyimine]

The polyimine which may be contained in the liquid crystal displacing agent of the present invention can be synthesized by subjecting the above polyamic acid to dehydration ring closure. The polyimine used in the present invention may be a fully sulfhydryl imide which is obtained by imidating all of the proline structure of the polyaminic acid, or may be a part of the structure of only the proline. The aminated amidate structure is a part of the quinone imide that coexists with the quinone imine structure. When the polymer contained in the liquid crystal alignment agent of the present invention is a polyimide, the ruthenium imidation ratio is preferably 40% or more. Here, the "rhodium imidization ratio" is a percentage expressed as a percentage of the ratio of the ruthenium structure in the polymer and the number of quinone imine structures contained in the total number of quinone imine structures. The imidization ratio can be determined by allowing the completely dried polyimine to be dissolved in a suitable deuterated solvent, such as deuterated dimethyl hydrazine, using tetramethyl decane as a reference material, and measuring at room temperature. ¹ H-NMR, calculated by the following formula (i): (In the formula (i), A1 is the proton peak area derived from the NH group (near 10 ppm), A2 is the proton peak area derived from the aromatic ring (7 to 8 ppm), and α is the polymer precursor (polyproline) The ratio of the number of protons in the aromatic ring to the protons of one NH group).

The dehydration ring closure of poly-proline is (1) heating the poly-proline, or (2) dissolving the poly-proline in an organic solvent, adding a dehydrating agent and a dehydration ring-closing catalyst to the solution, and The heating method is carried out in the case.

The reaction temperature in the method for heating polylysine in the above (1) is preferably from 50 to 200 ° C, more preferably from 60 to 170 ° C. When the reaction temperature is less than 50 ° C, the dehydration ring closure reaction cannot be sufficiently performed, and when the reaction temperature exceeds 200 ° C, the molecular weight of the obtained polyimine is lowered. The reaction time is preferably from 0.5 to 72 hours, more preferably from 1 to 10 hours.

On the other hand, in the above method (2) in which a dehydrating agent and a dehydration ring-closing catalyst are added to the polyaminic acid solution, an acid anhydride such as acetic anhydride, propionic anhydride or trifluoroacetic anhydride can be used as the dehydrating agent. Although the amount of the dehydrating agent is determined depending on the desired imidization ratio, the proline structure of the polyglycolic acid is preferably from 0.01 to 20 mol. As the dehydration ring-closing catalyst, a tertiary amine such as pyridine, trimethylpyridine, lutidine or triethylamine can be used. However, it is not limited to these. The amount of the dehydration ring-closing catalyst is preferably 0.01 to 10 moles relative to the amount of the dehydrating agent used in 1 mole. The yield of hydrazine imidation can be increased as the amount of the above-mentioned dehydrating agent and dehydration ring-clogging agent is increased. The organic solvent used in the dehydration ring closure reaction can be exemplified by the same organic solvent as exemplified in the synthesis of polyglycine. The reaction temperature of the dehydration ring closure reaction is preferably from 0 to 180 ° C, more preferably from 10 to 150 ° C. The reaction time is preferably from 1 to 12 hours, more preferably from 1 to 6 hours.

The ruthenium iodide polymer obtained in the above method (1) can be supplied to the liquid crystal alignment agent as it is, or can be supplied to the liquid crystal alignment agent after purification of the obtained ruthenium iodide polymer. On the other hand, the above method (2) A reaction solution containing a ruthenium iodide polymer is obtained. The reaction solution can be supplied to the liquid crystal alignment agent for preparation, or can be supplied to the liquid crystal alignment agent after removing the dehydrating agent and the dehydration ring-closing catalyst from the reaction solution, or can be supplied after the ruthenium iodide polymer is separated. The preparation to the liquid crystal alignment agent after the preparation of the liquid crystal alignment agent or the purification of the isolated imidized polymer. From the reaction solution removal dehydrating agent and the water ring-closing catalyst, a method such as solvent replacement can be suitably used. The isolation and purification of the ruthenium iodide polymer can be carried out by performing the same operation as the separation and purification method of the above polyamic acid.

[End modified polymer]

The polyaminic acid or polyimine used in the present invention may also be a terminal modified type having a molecular weight adjusted. By using the terminal-modified polymer, the coating properties and the like of the liquid crystal alignment agent can be further improved without impairing the effects of the present invention.

These terminal-modified polymers can be synthesized by adding an appropriate molecular weight modifier such as an acid-anhydride, a monoamine compound or a monoisocyanate compound to a reaction system in the synthesis of polyamic acid. The acid-anhydride herein may, for example, be exemplified by maleic anhydride, phthalic anhydride, isaconic anhydride, n-undecyl succinic anhydride, n-dodecyl succinic anhydride, n-tetradecyl succinic anhydride, n-hexadecyl group. Succinic anhydride and the like. The monoamine compound can be exemplified by, for example, aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-decylamine, n-decylamine, and Alkylamine, n-dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecylamine, n-octadecane Amine, n-icosylamine, etc. . The monoisocyanate compound can be exemplified by, for example, phenyl isocyanate, naphthyl isocyanate or the like.

The ratio of use of the molecular weight modifier to the total amount of the tetracarboxylic dianhydride and the diamine used in the synthesis of the polyamic acid is preferably 20 parts by weight or less, more preferably 10 parts by weight or less.

When the polyglycolic acid or the quinone imine polymer obtained as described above is a solution having a concentration of 10% by weight, a solution viscosity of 20 to 800 mPa·s is preferably maintained, and a solution viscosity of 30 to 500 mPa·s is better maintained.

The solution viscosity (mPa‧s) of the above polymer is a good solvent (for example, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.) using the polymer, and is formulated into a polymer solution having a concentration of 10% by weight. The value measured at 25 ° C using an E-type rotational viscometer.

[any additive]

The liquid crystal alignment agent of the present invention contains at least one polymer selected from the group consisting of polylysine and polyimine, and a solvent described later as essential components, but it is also within the range not detracting from the object of the present invention. An epoxy compound or a functional decane compound may also be contained as an optional additive. These may be added based on the purpose of further enhancing the adhesion of the formed liquid crystal alignment film to the surface of the substrate.

Examples of the epoxy compound include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, and polypropylene glycol diglycidyl ether. Neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerol diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3, 5,6-tetraglycidyl-2,4-hexanediol, N,N,N',N'-tetraglycidyl-p-phenylenediamine, N,N,N',N'-tetrahydration Glyceryl-m-phenylenediamine, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, N,N,N',N'-tetraglycidyl 4-,4'-diaminodiphenyl ether, N,N,N',N'-tetraglycidyl-2,2'-dimethyl-4,4'-diaminobiphenyl, N,N,N',N'-tetraglycidyl-1,2-diaminocyclohexane, N,N,N',N'-tetraglycidyl-1,3-diaminocyclohexane Alkane, N, N, N', N'-tetraglycidyl-1,4-diaminocyclohexane, bis(N,N-diglycidyl-4-aminocyclohexyl)methane, bis ( N,N-diglycidyl-2-methyl-4-aminocyclohexyl)methane, bis(N,N-diglycidyl-3-methyl-4- Cyclohexyl)methane, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, 1,4-bis(N,N-diglycidylaminomethyl)cyclohexane Alkane, 1,3-bis(N,N-diglycidylaminomethyl)benzene, 1,4-bis(N,N-diglycidylaminomethyl)benzene, 1,3,5-叁(N,N-diglycidylaminomethyl)cyclohexane, 1,3,5-anthracene (N,N-diglycidylaminomethyl)benzene, respectively, of the following formula (31)~( 35) Compounds indicated, etc.:

The blending ratio of the epoxy compounds is preferably 40% based on 100 parts by weight of the total amount of the polymer (the total amount of the polyamic acid and the ruthenium iodide polymer contained in the liquid crystal alignment agent, the same applies hereinafter). The amount is preferably 0.1 to 30 parts by weight or less.

The above functional decane compound may, for example, be exemplified by 3-aminopropyltrimethoxydecane, 3-aminopropyltriethoxydecane, 2-aminopropyltrimethoxy Baseline, 2-aminopropyltriethoxydecane, N-(2-aminoethyl)-3-aminopropyltrimethoxydecane, N-(2-aminoethyl)-3- Aminopropylmethyldimethoxydecane, 3-ureidopropyltrimethoxydecane, 3-ureidopropyltriethoxydecane, N-ethoxycarbonyl-3-aminopropyltrimethoxy Baseline, N-ethoxycarbonyl-3-aminopropyltriethoxydecane, N-triethoxydecylpropyltriethylamine, N-trimethoxydecylpropyltriene Ethyltriamine, 10-trimethoxydecyl-1,4,7-triazadecane, 10-triethoxydecyl-1,4,7-triazadecane, 9-trimethoxy Base alkyl-3,6-diazaindolyl acetate, 9-triethoxydecyl-3,6-diazaindolyl acetate, N-benzyl-3-aminopropyl Trimethoxydecane, N-benzyl-3-aminopropyltriethoxydecane, N-phenyl-3-aminopropyltrimethoxydecane, N-phenyl-3-aminopropyltri Ethoxy decane, N-bis(ethylene oxide)-3-aminopropyltrimethoxydecane, N-bis(ethylene oxide)-3-aminopropyltriethoxydecane, 3- (N-allyl-N-glycidyl)aminopropyltrimethoxydecane, 3-( N,N-diglycidyl)aminopropyltrimethoxydecane, and the like.

The blending ratio of the functional decane compound is preferably 2 parts by weight or less, more preferably 0.2 to 1 part by weight, per 100 parts by weight of the total amount of the polymer.

[Liquid alignment agent]

The liquid crystal alignment agent of the present invention comprises at least one polymer selected from the group consisting of polylysine and polyimine, and any optional component used as needed, dissolved in a solvent.

The solvent used in the liquid crystal alignment agent of the present invention is: (A) a first solvent consisting of the compound represented by the above formula (I), and (B) selected from the group consisting of N-methyl-2-pyrrolidone, γ-butyrolactone, 1,3-dimethyl a second solvent composed of at least one of the group consisting of 2-imidazolidinone, N,N-dimethylformamide, and N,N-dimethylacetamide, and (C) selected from the group consisting of A third solvent composed of at least one of a group consisting of butyl cellosolve, diacetone alcohol, propylene carbonate, diethylene glycol diethyl ether, and ethyl 3-ethoxypropionate.

The compound represented by the above formula (I) preferably has a boiling point of 140 to 200 ° C and a surface tension of preferably 18 to 27 mN/m. The boiling point and surface tension of the compound represented by the above formula (I) are in the above range, and R in the above formula (I) is preferably an alkyl group having 4 to 8 carbon atoms, more preferably 4 to 6 carbon atoms. The alkyl group is specifically exemplified by, for example, a pentyl group, an isopentyl group and the like.

Specific examples of the compound represented by the above formula (I) include, for example, dipentyl ether, diisoamyl ether, and the like, and at least one selected from the group consisting of these is preferably used.

In the liquid crystal alignment agent of the present invention, the ratio of the first solvent (A) to the total amount of the first solvent (A), the second solvent (B) and the third solvent (C) is preferably 0.5 to 20% by weight, more preferably 1 to 10% by weight. The ratio of the (B) second solvent is preferably from 10 to 94.5% by weight, more preferably, relative to the total of (A) the first solvent, (B) the second solvent, and (C) the third solvent. 30~89% by weight. The ratio of the third solvent (C) is preferably from 5 to 70% by weight, more preferably from 5 to 70% by weight based on the total of (A) the first solvent, (B) the second solvent, and (C) the third solvent. 10~60% by weight.

In the liquid crystal alignment agent of the present invention, if the first solvent (A), the second solvent (B), and the third solvent (C) are preferably contained in the above ratio, The excellent coatability in the inkjet coating method can be preferably achieved by the desired effect of the present invention. In particular, when the compound represented by the above formula (I) having a boiling point and a surface tension within the above range is used as the first solvent (A), even when the content ratio of the first solvent (A) is small, the maximum is It is preferred to limit the purpose of the present invention.

The liquid crystal alignment agent of the present invention may also use only the above (A) first solvent, (B) second solvent and (C) third solvent as a solvent, or (A) first solvent, (B) The second solvent and (C) the third solvent are used in combination with other solvents. Other solvents which can be used herein are exemplified by, for example, γ-butyrolactam, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, methyl methoxypropionate. , ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol propyl ether, ethylene glycol isopropyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, Diethylene glycol dimethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate Wait.

The solvent composition in the liquid crystal alignment agent of the present invention is such that the polymer in the liquid crystal alignment agent and any additives are not precipitated, and the surface tension of the liquid crystal alignment agent is in the range of 20 to 40 mN/m. From this point of view, the total amount of (A) the first solvent, (B) the second solvent, and (C) the third solvent in the liquid crystal alignment agent of the present invention is relatively good in proportion to the total amount of the solvent. It is 30% by weight or more, more preferably 50% by weight or more, and still more preferably 70% by weight or more.

The solid content concentration in the liquid crystal alignment agent of the present invention (the ratio of the total weight of the components other than the solvent in the liquid crystal alignment agent to the total weight of the liquid crystal alignment agent) is selected in consideration of viscosity, volatility, etc., but preferably In 1~10 The range of %. In other words, the liquid crystal alignment agent of the present invention forms a coating film of a liquid crystal alignment film by coating the alignment agent on the surface of the substrate, and if the solid concentration of the liquid crystal alignment agent is less than 1% by weight, the film of the coating film If the thickness is too small, a good liquid crystal alignment film cannot be obtained. On the other hand, if the solid content concentration exceeds 10% by weight, the film thickness of the coating film is too large to obtain a good liquid crystal alignment film, and if the liquid crystal alignment agent is made sticky, When it is increased, there is a case where the coating property is deteriorated. The optimum solid concentration ranges from 2 to 8% by weight. Therefore, the solution viscosity of the liquid crystal alignment agent is preferably in the range of 3 to 15 mPa·s.

The temperature of the liquid crystal alignment agent of the present invention is preferably from 0 ° C to 60 ° C, more preferably from 20 ° C to 40 ° C.

[Method of Manufacturing Liquid Crystal Display Element]

The liquid crystal display element of the present invention comprises a liquid crystal alignment film formed of the above liquid crystal alignment agent of the present invention.

The liquid crystal display element of the present invention can be produced, for example, by the following method: (1) First, the liquid crystal alignment film of the present invention is applied onto a pair of substrates, and the solvent is removed to form a coating film. Here, in the case where the display mode of the liquid crystal display element to be manufactured is a vertical electric field method such as a TN type, an STN type, or a VA type, two substrates each having a patterned transparent conductive film on one surface are used as A pair of substrates. On the other hand, in the case where the display mode of the liquid crystal display element to be manufactured is the lateral electric field method, a substrate provided with a transparent conductive film having a comb-tooth pattern and a substrate having no transparent conductive film are used as a pair of substrates.

In either case, the liquid crystal alignment agent is coated on the substrate (the substrate having the transparent conductive film on the surface of the substrate having the transparent conductive film). As the substrate, glass such as float glass, soda lime glass, or the like; polyethylene terephthalate, polybutylene terephthalate, polyether oxime, polycarbonate, poly(alicyclic olefin) can be used. a transparent substrate made of plastic. As the transparent conductive film provided on one surface of the substrate, for example, a NESA film composed of tin oxide (SnO ₂ ) (registered trademark of PPG Corporation, USA), and indium oxide-tin oxide (In ₂ O ₃ -SnO ₂ ) can be used. An ITO film or the like is formed. Moreover, the transparent patterned conductive film can be obtained by forming a pattern by a heat ‧ etching method after forming an unpatterned transparent conductive film, and using a mask having a desired pattern when forming a transparent conductive film. A method of directly forming a patterned transparent conductive film or the like.

The liquid crystal alignment agent is applied onto the substrate by a suitable coating method such as a roll coating method, a spin coating method, a printing method, or an inkjet method. When the liquid crystal alignment agent of the present invention employs an inkjet printing method as a coating method, it has an advantage that particularly good coating properties (printability) can be exhibited.

When the liquid crystal alignment agent is applied, in order to improve the adhesion between the surface of the substrate and the transparent conductive film and the coating film, a functional decane compound or a compound of a functional titanium may be applied to the surface to be coated of the substrate.

After coating, preheating (prebaking) is preferably carried out for the purpose of preventing the vertical flow of the alignment agent liquid. The prebaking temperature is preferably from 30 to 200 ° C, more preferably from 40 to 150 ° C, and most preferably from 40 to 100 ° C. The prebaking time is preferably from 10 seconds to 20 minutes, more preferably from 10 seconds to 10 minutes. Subsequently, a firing (post-baking) step is performed for the purpose of completely removing the solvent or the like. The purpose of this post-baking is to The coating film completely removes the solvent, but when the polymer contained in the liquid crystal alignment agent of the present invention is a polymer having a proline structure, it can also be used to heat the polymer contained in the liquid crystal alignment agent of the present invention. The amino acid structure is further subjected to dehydration ring closure to achieve a higher imidization rate of the coating film. The post-baking temperature is preferably from 80 to 300 ° C, more preferably from 120 to 250 ° C. The post-baking time is preferably from 5 to 60 minutes, more preferably from 5 to 30 minutes.

According to this, a coating film which becomes a liquid crystal alignment film can be formed. The film thickness of the coating film formed is preferably from 0.001 to 1 μm, more preferably from 0.005 to 0.5 μm.

When the liquid crystal display element using the liquid crystal alignment agent of the present invention is a VA type liquid crystal display element, for example, a liquid crystal alignment agent is formed by forming a protrusion-like structure on a substrate as described in JP-A-2002-327058, and an improved viewing angle can be realized. characteristic.

(2) In the case where the display mode of the liquid crystal display element to be manufactured is the VA type, the coating film formed as described above may be used as the liquid crystal alignment film, but the rubbing treatment may be performed as described below. On the other hand, in the case where the display mode of the liquid crystal display element to be manufactured is a vertical electric field method other than the VA type and the case of the horizontal electric field method, the formed coating film surface can be subjected to a rubbing treatment.

The rubbing treatment can be carried out by rubbing a roll formed by a cloth composed of fibers such as nylon, crepe or cotton in a certain direction. Thereby, it becomes a liquid crystal alignment film which gives the coating film the alignment energy of a liquid crystal molecule. In addition, as for the coating film after the rubbing treatment, the liquid crystal alignment is performed by irradiating a part of the liquid crystal alignment film with ultraviolet rays as shown in, for example, JP-A-H06-222366 and JP-A-6-281937. Pretilt angle change in a part of the film The treatment is carried out, or a resist film is formed on one of the surfaces of the formed liquid crystal alignment film as shown in Japanese Laid-Open Patent Publication No. H5-107544, and the rubbing film is removed in a different direction from the rubbing treatment previously performed. The treatment ensures that the liquid crystal alignment film maintains different liquid crystal alignment energies per region, thereby improving the field of view characteristics of the prepared liquid crystal display device.

(3) Two substrates on which the liquid crystal alignment film as described above is formed are prepared, and liquid crystal cells are disposed between the two substrates disposed oppositely to produce a liquid crystal cell. Here, when the coating film is subjected to the rubbing treatment, the two substrates are disposed so as to face each other at a specific angle, for example, orthogonally or anti-parallel, in the rubbing direction of each of the coating films.

The manufacture of the liquid crystal cell exemplifies, for example, the following two methods.

The first method is a conventional method. First, each liquid crystal alignment film is disposed such that two substrates are opposed to each other with a gap (liquid crystal cell) opposed thereto, and a liquid crystal cell is formed by bonding a peripheral portion of the two substrates with a sealant on the surface of the substrate and a sealant. After the inside of the gap is filled with the liquid crystal, the injection hole is sealed to constitute the liquid crystal cell.

The second method is a method called ODF (One Drop Fill). For example, an ultraviolet curable sealing material is applied to a predetermined position on one of the two substrates on which the liquid crystal alignment film is formed, and the liquid crystal is dropped on the liquid crystal alignment film to lower the liquid crystal, so that the liquid crystal alignment film is opposed to the film. After the other substrate is bonded, the entire surface of the substrate is irradiated with ultraviolet rays to cure the sealing agent to produce a liquid crystal cell.

It is preferred that the liquid crystal cell manufactured as described above is heated by any method to a temperature at which the liquid crystal used is made uniform, and then slowly The mixture was cooled to room temperature, thereby removing the flow alignment at the time of liquid crystal injection.

Therefore, the liquid crystal display element of the present invention can be obtained by laminating a polarizing plate on the outer surface of the liquid crystal cell.

Here, as the sealant, for example, an epoxy resin containing a curing agent and an alumina ball 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 type liquid crystal cell, a nematic liquid crystal having a negative dielectric anisotropy such as a dicyanobenzene liquid crystal, a pyridazine liquid crystal, a Schiff base liquid crystal, or an azooxy (azoxy) is preferably used. ) is a liquid crystal, a biphenyl liquid crystal, a phenylcyclohexane liquid crystal, or the like. In the case of a TN type liquid crystal cell or an STN type liquid crystal cell, a nematic liquid crystal having positive dielectric anisotropy, for example, a biphenyl liquid crystal, a phenylcyclohexane liquid crystal, an ester liquid crystal, or a terphenyl liquid crystal, is preferably used. A biphenylcyclohexane liquid crystal, a pyrimidine liquid crystal, a dioxane liquid crystal, a bicyclooctane liquid crystal, a cubane liquid crystal, or the like. Further, in the liquid crystals, a cholesterol acid type liquid crystal such as cholesteric chlorine, cholesteryl phthalate or cholesteryl carbonate may be further added or sold under the trade names C-15 and CB-15 (manufactured by Merck). It is used as a palmitic agent; a strong dielectric liquid crystal such as p-norbymethoxybenzylidene-p-amino-2-methylbutyl laurate or the like.

For the polarizing plate to be bonded to the outer surface of the liquid crystal cell, a polarizing film called a "H film" which is obtained by stretching and aligning polyvinyl alcohol while absorbing iodine may be exemplified by a polarizing plate held by a cellulose acetate protective film or an H film. A polarizing plate that constitutes itself.

Example

The invention is more specifically illustrated by the following examples, but the invention is not limited by the examples.

Synthesis Example 1

Adding 10 millimolar as a diamine compound to the compound represented by the above formula (11), 70 millimoles of p-phenylenediamine and 20 millimolar 4 in N-methyl-2-pyrrolidone , 4'-diaminodiphenylmethane, and 100 millimoles of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as tetracarboxylic dianhydride, and tetracarboxylic dianhydride and diamine compound A total amount of the solution was 20% by weight based on the total amount of the solution, and the reaction was carried out at 60 ° C for 4 hours to obtain a solution containing polyamic acid.

Adding 2 times of molar pyridine and acetic anhydride to the total amount (theoretical value) of the proline structure contained in the polyglycolic acid in the solution containing the polyamic acid, and heating to 110 ° C for dehydration ring closure reaction 4 hours.

The obtained solution was poured into a large excess of diethyl ether to obtain a precipitate, which was recovered and dried under reduced pressure to obtain a polyimine (PI-1) having a ruthenium iodide ratio of 78%.

Synthesis Example 2

110 g (0.50 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as tetracarboxylic dianhydride and 38 g (0.35 mol) of p-phenylenediamine as a diamine, 20 g ( 0.1 moles of 4,4'-diaminodiphenylmethane and 26 grams (0.05 moles) of 3-(3,5-diaminobenzimidyloxy)cholestane dissolved in 800 grams of N-A Base-2-pyridyl The reaction was carried out for 6 hours at 60 ° C in a flavonone to obtain a solution containing polyamic acid. A small amount of the obtained polyaminic acid solution was added, and N-methyl-2-pyrrolidone was added to obtain a solution having a polyglycine concentration of 10% by weight, and the solution viscosity was determined to be 60 mPa·s.

Next, 1.80 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, and 80 g of pyridine and 100 g of acetic anhydride were added, and a dehydration ring-closure reaction was carried out at 110 ° C for 4 hours. After the dehydration ring closure reaction, the solvent in the solvent replacement system is replaced by a new γ-butyrolactone (by the solvent replacement operation, the pyridine and acetic anhydride used in the dehydration ring closure reaction can be excluded from the system, the same applies hereinafter). About 1,100 g of a solution containing 15% by weight of a ruthenium iodide polymer (PI-2) having a ruthenium iodide ratio of about 80% was obtained. The ruthenium iodide polymer solution was added in small portions, and γ-butyrolactone was added to obtain a solution having a polyglycine concentration of 10% by weight, and the solution viscosity was determined to be 87 mPa·s.

Synthesis Example 3

110 g (0.50 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as tetracarboxylic dianhydride and 43 g (0.40 mol) as diamine p-phenylenediamine and 52 g ( 0.10 mol) 3-(3,5-diaminobenzylideneoxy)cholesterane was dissolved in 830 g of N-methyl-2-pyrrolidone, and the reaction was carried out at 60 ° C for 6 hours to obtain A solution containing polylysine. A small amount of the obtained polyaminic acid solution was added, and N-methyl-2-pyrrolidone was added to obtain a solution having a polyglycine concentration of 10% by weight, and the solution viscosity was determined to be 60 mPa·s.

Next, 1,900 g of N-methyl-2-pyrrolidone was added to the obtained polyaminic acid solution, and 40 g of pyridine and 51 g of acetic anhydride were added, and at 110 ° C. The dehydration ring closure reaction was carried out for 4 hours. After the dehydration ring closure reaction, the solvent in the system is replaced with a new N-methyl-2-pyrrolidone, thereby obtaining about 1,200 g of ruthenium imidization containing 15% by weight of hydrazine imidization rate of about 50%. A solution of the polymer (PI-3). The ruthenium iodide polymer solution was added in small portions, and N-methyl-2-pyrrolidone was added to obtain a solution having a polyglycine concentration of 10% by weight, and the solution viscosity was determined to be 47 mPa·s.

Synthesis Example 4

110 g (0.50 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride of tetracarboxylic dianhydride and 49 g (0.45 mol) as p-phenylenediamine of diamine and 26 g ( 0.05 mol) 3-(3,5-diaminobenzylideneoxy)cholestane was dissolved in 750 g of N-methyl-2-pyrrolidone and reacted at 60 ° C for 6 hours to obtain A solution containing polylysine. A small amount of the obtained polyaminic acid solution was added, and N-methyl-2-pyrrolidone was added to obtain a solution having a polyglycine concentration of 10% by weight, and the solution viscosity was determined to be 58 mPa·s.

Next, 1,800 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, and 40 g of pyridine and 51 g of acetic anhydride were added, and a dehydration ring-closure reaction was carried out at 110 ° C for 4 hours. After the dehydration ring closure reaction, the solvent in the solvent is replaced by a new N-methyl-2-pyrrolidone to obtain about 1,100 g of a ruthenium imidization polymerization containing 15% by weight of a ruthenium iodide ratio of about 50%. A solution of the substance (PI-4). The ruthenium iodide polymer solution was added in small portions, and N-methyl-2-pyrrolidone was added to obtain a solution having a polyglycine concentration of 10% by weight, and the solution viscosity was determined to be 85 mPa·s.

Example 1

The polyimine (PI-1) obtained in the above Synthesis Example 1 was dissolved in a mixed solvent composed of diisoamyl ether, γ-butyrolactone, N-methyl-2-pyrrolidone, and butyl cellosolve ( In the mixing ratio (weight ratio) = 5:30:40:25), a liquid crystal alignment agent having a solution viscosity of 6 mPa ‧ was obtained. It was filtered through a filter having a pore size of 0.2 μm for the following evaluation.

<Evaluation of inkjet coating properties>

As a substrate on which a liquid crystal alignment agent is applied, a glass substrate having a transparent electrode made of ITO is heated on a hot plate at 200 ° C for 1 minute, followed by ultraviolet/ozone cleaning, and the contact angle with the water on the transparent electrode surface becomes Use immediately after 10∘.

The above-mentioned formulated liquid crystal alignment agent (filtered) was applied onto the transparent electrode surface of the glass substrate with the above transparent electrode using an inkjet coater (manufactured by Shibaura Mechatronics Co., Ltd.). At this time, the coating conditions were 2,500 times/(nozzle ‧ minutes), and the discharge amount was 250 mg/10 seconds, and the coating was applied twice (total 4 times). After coating, after standing for 1 minute, it was heated at 80 ° C to form a coating film having an average film thickness of 0.1 μm. Under the irradiation of the interference fringe lamp (sodium lamp), each of the obtained coating films was observed with the naked eye, and it was judged that the ink-jet coating property was "good" by the fact that neither of the corrugation nor the cracking was observed, and at least corrugations and cracks were found. In one case, it was judged that the inkjet coating property of the liquid crystal alignment agent was "good" after the inkjet coating property "bad" was evaluated.

<Manufacture of liquid crystal cell>

A liquid crystal cell for evaluating a liquid crystal alignment agent and a voltage holding ratio was produced as follows. In the production of the liquid crystal cell described below, the liquid crystal alignment agent was applied by a spin coating method, and this was compared with the comparative example described later in comparison with the inkjet coating property.

On the transparent electrode surface of the glass substrate with the transparent electrode composed of the ITO film, the above-mentioned formulated liquid crystal alignment agent (filtering the latter) was applied by spin coating, and pre-baked on a hot plate at 80 ° C. After baking for 1 minute, it was post-baked on a hot plate at 200 ° C for 10 minutes to form a coating film having an average film thickness of 0.1 μm. By repeating the same operation, a pair of (two sheets) substrates having a liquid crystal alignment film on a transparent conductive film were produced.

Applying an epoxy resin adhesive having a diameter of 5.5 μm of alumina balls to the outer edges of the pair of substrates having the liquid crystal alignment film, the surfaces of the liquid crystal alignment films are relatively overlapped and pressed, and then The agent hardens. Next, a nematic liquid crystal (manufactured by Merck Co., Ltd., MLC-6601) was filled between the pair of substrates from the liquid crystal injection port, and then the liquid crystal injection port was sealed with an acrylic photocurable adhesive to prepare a liquid crystal cell.

<Evaluation of liquid crystal alignment>

The liquid crystal cell produced by the above-mentioned liquid crystal cell was visually observed under the cross-polarization of Cross Nicol, and the liquid crystal alignment was judged to be "good" when there was no light leakage, and the liquid crystal alignment was evaluated as "bad" when the light leakage was observed. The liquid crystal alignment is "good".

<Evaluation of voltage retention rate>

When a voltage of 5 V was applied to the liquid crystal cell obtained above for 60 microseconds and a time interval of 167 msec, the voltage holding ratio of 167 msec after the application was released was measured. The measuring device used VHR-1 manufactured by Dongyang Technic. When the value is 95% or more, it is judged as "good", and when it is less than 95%, the voltage holding ratio "bad" is evaluated, and the voltage holding ratio of the liquid crystal cell is "good".

Example 2

Diisoamyl ether, γ-butyrolactone, N-methyl-2-pyrrolidone and butyl cellosolve are added to the solution containing the ruthenium iodide polymer (PI-2) obtained in the above Synthesis Example 2, The solvent composition is diisoamyl ether: γ-butyrolactone: N-methyl-2-pyrrolidone: butyl cellosolve = 5:30:40:25 (weight ratio), formulated to a solution viscosity of 6 mPa‧s Liquid crystal alignment agent. This was filtered through a filter having a pore size of 0.2 μm, and evaluated as in Example 1. The evaluation results are shown in Table 1.

Example 3

Diisoamyl ether, N-methyl-2-pyrrolidone and butyl cellosolve were added to the solution containing the ruthenium iodide polymer (PI-3) obtained in the above Synthesis Example 3, and the solvent composition was diisoamyl. Ether: N-methyl-2-pyrrolidone: butyl cellosolve = 5:50:45 (by weight), formulated into a liquid crystal alignment agent having a solution viscosity of 6 mPa ‧ . This was filtered through a filter having a pore size of 0.2 μm, and evaluated as in Example 1. The evaluation results are shown in Table 1.

Example 4

Diisoamyl ether, N-methyl-2-pyrrolidone and butyl cellosolve were added to the solution containing the ruthenium iodide polymer (PI-4) obtained in the above Synthesis Example 4, and the solvent composition was diisoamyl. Ether: N-methyl-2-pyrrolidone: butyl cellosolve = 5:50:45 (by weight), formulated into a liquid crystal alignment agent having a solution viscosity of 6 mPa ‧ . This was filtered through a filter having a pore size of 0.2 μm, and evaluated as in Example 1. The evaluation results are shown in Table 1.

Comparative example 1

Diisoamyl ether and N-methyl-2-pyrrolidone were added to a solution containing the ruthenium iodide polymer (PI-3) obtained in the above Synthesis Example 3, and the solvent composition was diisoamyl ether: N- Methyl-2-pyrrolidone = 5:95 (weight ratio), formulated into a liquid crystal alignment agent having a solution viscosity of 6 mPa ‧ . This was filtered through a filter having a pore size of 0.2 μm, and evaluated as in Example 1. The evaluation results are shown in Table 1.

Comparative example 2

To the solution containing the ruthenium iodide polymer (PI-2) obtained in the above Synthesis Example 2, butyrolactone, N-methyl-2-pyrrolidone and butyl cellosolve were added, and the solvent composition was butyrolactone: N-methyl-2-pyrrolidone: butyl cellosolve = 40:30:30, formulated into a liquid crystal alignment agent having a solution viscosity of 6 mPa ‧ . This was filtered through a filter having a pore size of 0.2 μm, and evaluated as in Example 1. The evaluation results are shown in Table 1.

(Effect of the invention)

Since the liquid crystal alignment agent of the present invention is excellent in coatability when it is used in an inkjet coating method in particular, it can improve the yield of a product in a manufacturing process by a large-scale production line. Further, the liquid crystal alignment film obtained from the liquid crystal alignment agent of the present invention is excellent in liquid crystal alignment properties and electrical properties, and is particularly suitable for a vertical alignment type liquid crystal display device.

The liquid crystal display element of the present invention having the above liquid crystal alignment film can be suitably used in various devices, for example, as a display device for a desktop computer, a wristwatch, a clock, a mobile phone, a counter display panel, a word processor, a personal computer, a liquid crystal television, or the like.

Claims (6)

A liquid crystal alignment agent comprising at least one polymer selected from the group consisting of polylysine obtained by reacting a tetracarboxylic dianhydride with a diamine compound and polyimine obtained by dehydration ring closure, and a solvent thereof, characterized in that The solvent contains: (A) a first solvent consisting of a compound represented by the following formula (I): (in the formula (I), R is independently an alkyl group having 3 to 10 carbon atoms); (B) a second solvent consisting of at least one selected from the group consisting of N-methyl-2-pyrrole Pyridone, γ-butyrolactone, 1,3-dimethyl-2-imidazolidinone, N,N-dimethylformamide, and N,N-dimethylacetamide; and (C) A third solvent composed of at least one of the group consisting of butyl cellosolve, diacetone alcohol, propylene carbonate, diethylene glycol diethyl ether, and ethyl 3-ethoxypropionate. The liquid crystal alignment agent of claim 1, wherein the ratio of the first solvent to the total amount of the (A) first solvent, the (B) second solvent, and the (C) third solvent is 1.0. ~10% by weight, (B) the ratio of the second solvent is 30 to 89.0% by weight, and the ratio of the (C) third solvent is 10 to 60% by weight. The liquid crystal alignment agent according to claim 1 or 2, wherein the compound represented by the above formula (I) has a boiling point of 140 to 200 ° C and a surface tension of 18 to 27 mN/m. The liquid crystal alignment agent of claim 3, wherein the compound represented by the above formula (I) is at least one selected from the group consisting of dipentyl ether and diisoamyl ether. The liquid crystal alignment agent according to claim 1 or 2, wherein the tetracarboxylic dianhydride comprises at least one selected from the group consisting of: a compound represented by the following formula (1): (In the formula (1), R ^{1 is} each independently a hydrogen atom, a chlorine atom or an alkyl group having 1 to 6 carbon atoms), and a compound represented by the following formula (2): (In the formula (2), R ^{2 is} independently an alkyl group having 1 to 6 carbon atoms, n is an integer of 0 to 4), pyromellitic dianhydride, and 1,2,4-tricarboxycyclopentyl acetic acid Anhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 1,2,3,4-cyclopentane tetracarboxylic dianhydride, and 1,2,4,5-cyclohexanetetracarboxylic dianhydride . A liquid crystal display element comprising a liquid crystal alignment film obtained by the liquid crystal alignment agent of claim 1 or 2.