TW201418848A - Liquid crystal alignment agent, liquid crystal alignment film and method for producing the same, liquid crystal display device - Google Patents

Abstract

A liquid crystal alignment agent is provided, which has excellent coating property to a substrate. The liquid crystal alignment agent contains a polymer (A) containing a polyimide, etc. and a solvent, wherein the solvent contains 1 to 60 wt% of a compound (b) represented by the following formula (1) relative to the total amount of the solvent. HO-R1-OH (1) In formula (1), R1 is a divalent chain hydrocarbon group or an alicyclic hydrocarbon group having 2 to 10 carbons or a divalent group having ''-O-'' between a carbon-carbon bond in the chain hydrocarbon group or the alicyclic hydrocarbon group.

Description

Liquid crystal alignment agent, liquid crystal alignment film, manufacturing method thereof, liquid crystal display element

The present invention relates to a liquid crystal alignment agent, a liquid crystal alignment film, and a liquid crystal display element. In particular, the present invention relates to a liquid crystal alignment agent suitable for manufacturing a large liquid crystal panel or a liquid crystal panel having a complicated shape, and the like, and the use of the liquid crystal alignment agent. A liquid crystal alignment film and a liquid crystal display element having the same.

Conventionally, regarding the liquid crystal display element, various driving methods have been developed in which the electrode structure or the liquid crystal molecules used are different in physical properties, manufacturing steps, and the like, and for example, a twisted nematic (TN) type or a super twisted nematic (known) Super Twisted Nematic, STN), Vertical Alignment (VA), In-Plane Switching (IPS), Fringe Field Switching (FFS), Polymer Stabilized (Polymer Sustained) Various liquid crystal display elements such as Alignment, PSA). These liquid crystal display elements have a liquid crystal alignment film for aligning liquid crystal molecules. About the material of the liquid crystal alignment film In view of the fact that various properties such as heat resistance, mechanical strength, and affinity with liquid crystals are good, polyamic acid or polyimine is usually used.

In the liquid crystal alignment agent, a polymer component such as polyacrylic acid or polyimine is dissolved in a solvent, and the liquid crystal alignment agent is applied onto a substrate, preferably by heating, thereby forming a liquid crystal alignment film. As a method of applying a liquid crystal alignment agent to a substrate, a method using an offset printing apparatus has been conventionally used. However, with the increase in size of liquid crystal panels in recent years, there is a possibility that coating is not applied when a liquid crystal alignment agent is applied onto a substrate. Equal defect (demerit). Therefore, in order to eliminate such a problem, in recent years, a coating method using an inkjet method has been introduced in the manufacturing process of a large liquid crystal panel. In addition, various liquid crystal alignment agents to be applied to the application by the inkjet method have been proposed (see, for example, Patent Document 1 and Patent Document 2).

[Previous Technical Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2008-10899

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2009-300465

According to the coating by the inkjet method, it is possible to achieve a reduction in coating unevenness of the liquid crystal alignment agent when manufacturing a large liquid crystal panel, but there are disadvantages in that, at the end of the coating region, the amount of dripping or coating is insufficient. The film thickness is easily thinned. Such a film thickness defect causes display unevenness of the liquid crystal panel. Therefore, in a large liquid crystal panel, the quality of the display region has been ensured by designing the edge of the panel to be wide. However, in recent years, in order to achieve higher quality of the liquid crystal panel, narrow edge formation has been achieved, and in order to achieve this, the coating property of the liquid crystal alignment agent is required to be further improved.

Further, in recent years, with the expansion of the use of liquid crystal display elements, development of liquid crystal displays having complicated shapes such as curved displays has been progressing. In the manufacture of such a display, it is necessary to apply a liquid crystal alignment agent to a substrate having a complicated shape. Therefore, it is difficult to form a uniform coating film on the substrate, which causes problems such as poor alignment.

The present invention has been made in view of the above problems, and a main object thereof is to provide a liquid crystal alignment agent which is excellent in applicability to a substrate.

The inventors of the present invention have conducted intensive studies to achieve the problems of the prior art as described above, and have found that the problem can be solved by adding a specific compound as a part of the solvent component of the liquid crystal alignment agent, thereby completing the present problem. invention. Specifically, according to the present invention, the following liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element are provided.

The present invention provides, in one aspect, a liquid crystal alignment agent comprising at least one polymer (A) selected from the group consisting of polylysine, polyphthalate, and polyamidene, and a solvent, and The solvent (1) is a compound (b) represented by the following formula (1) in an amount of from 1% by weight to 60% by weight based on the total amount of the solvent.

[Chemical 1] HO-R ¹ -OH (1)

In the formula (1), R ¹ is a divalent chain hydrocarbon group or an alicyclic hydrocarbon group having 2 to 10 carbon atoms, or contains "-O-" between the carbon-carbon bond of the chain hydrocarbon group or the alicyclic hydrocarbon group. Divalent base.

In another aspect, the present invention provides a liquid crystal alignment film formed using the liquid crystal alignment agent. Further, the present invention provides a liquid crystal display element including the liquid crystal alignment film.

According to the liquid crystal alignment agent of the present invention, by including the compound (b) in the liquid crystal alignment agent, it is possible to narrow the region where the film thickness is defective as much as possible at the end portion of the coating region. Further, since the liquid crystal display element of the present invention has the liquid crystal alignment film formed using the liquid crystal alignment agent of the present invention, display unevenness due to film thickness defects is less likely to occur at the end portion of the liquid crystal alignment film, and narrow edge can be achieved. Thereby, it is possible to ensure a display area as large as possible with respect to the size of the support (edge) of the display portion. In addition, when used as a multi-display, the non-display area between the displays can be made as small as possible.

Further, according to the liquid crystal alignment agent of the present invention, by including the compound (b) in the liquid crystal alignment agent, a uniform coating film can be formed on a substrate having a complicated shape such as a curved shape. Further, the liquid crystal display element of the present invention can be applied to a liquid crystal display having a complicated shape such as a curved surface panel, and in the case of being applied to such a liquid crystal display, the liquid crystal alignment property is also good.

The liquid crystal alignment agent of the present invention contains at least one polymer (A) selected from the group consisting of polylysine, polyphthalate, and polyimine, and a solvent. Hereinafter, each component contained in the liquid crystal alignment agent of the present invention and other components optionally arbitrarily prepared will be described.

<Polymer (A): Polylysine>

The polyproline which is the polymer (A) of the present invention can be obtained by reacting a tetracarboxylic dianhydride with a diamine compound.

[tetracarboxylic dianhydride]

Examples of the tetracarboxylic dianhydride used for the synthesis of the polyamic acid of the present invention include aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, and aromatic tetracarboxylic dianhydride. Specific examples of the tetracarboxylic dianhydride include aliphatic tetracarboxylic dianhydride, for example, 1,2,3,4-butanetetracarboxylic dianhydride, and the like; for example, an alicyclic tetracarboxylic dianhydride can be mentioned. Out: 1,2,3,4-cyclobutane tetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentyl 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, 1,3,3a,4,5,9b-six Hydrogen-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- Furyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 3,5,6-tricarboxy-2-carboxymethylnorbornane-2:3,5:6- Anhydride, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride, 4,9-dioxatricyclo[5.3.1.0 ^2,6 ] Monoalkane-3,5,8,10-tetraketone, cyclohexanetetracarboxylic dianhydride, etc., and aromatic tetracarboxylic dianhydride, for example, pyromellitic dianhydride, etc., other than this, Japan can be used. The tetracarboxylic dianhydride disclosed in Japanese Laid-Open Patent Publication No. 2010-97188. Further, the tetracarboxylic dianhydride may be used alone or in combination of two or more.

The tetracarboxylic dianhydride used for the synthesis preferably contains an alicyclic tetracarboxylic dianhydride from the viewpoints of transparency and solubility in a solvent. Further, among the alicyclic tetracarboxylic dianhydrides, it is preferred to contain a compound selected from the group consisting of 2,3,5-tricarboxycyclopentyl 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, 1,3,3a,4,5,9b-hexahydro -8-Methyl-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione, 2,4,6, At least one of the group consisting of 8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride and 1,2,3,4-cyclobutanetetracarboxylic dianhydride, More preferably, it contains a compound selected from 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-di At least one of a group consisting of an anhydride and 1,2,3,4-cyclobutanetetracarboxylic dianhydride (hereinafter also referred to as a specific tetracarboxylic dianhydride).

In the case where the specific tetracarboxylic dianhydride is contained as the tetracarboxylic dianhydride used in the synthesis, the specific tetracarboxylic dianhydride is specific to the total amount of the tetracarboxylic dianhydride used in the synthesis of the polyamic acid. The total content is preferably 10 mol% or more, more preferably 20 mol% to 100 mol%, still more preferably 50 mol% to 100 mol%.

[diamine compound]

Examples of the diamine compound used for the synthesis of the polyglycolic acid of the present invention include an aliphatic diamine, an alicyclic diamine, an aromatic diamine, and a diamine organic decane. Specific examples of the diamine compound include aliphatic methylene diamine, 1,3-propanediamine, tetramethylene diamine, pentamethylene diamine, and hexamethylene group. Diamines and the like; examples of the alicyclic diamines include 1,4-diaminocyclohexane, 4,4'-methylenebis(cyclohexylamine), and 1,3-bis(aminomethyl) Cyclohexane or the like; examples of the aromatic diamine include p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfide, 1,5 -diaminonaphthalene, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 2,7-Diaminoguanidine, 4,4'-diaminodiphenyl ether, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 9,9-bis ( 4-aminophenyl)anthracene, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2-bis(4-aminophenyl)hexafluoropropane, 4,4'-(p-phenylene diisopropyl)diphenylamine, 4,4'-(m-phenylene diisopropyl)diphenylamine, 1,4-bis(4-aminophenoxyl) Benzo, 4,4'-bis(4-aminophenoxy)biphenyl, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3 ,6-diaminoacridine, 3,6-diamine Carbazole, N-methyl-3,6-diaminocarbazole, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N, N'-bis(4-aminophenyl)-benzidine, N,N'-bis(4-aminophenyl)-N,N'-dimethylbenzidine, 1,4-bis-(4 -aminophenyl)-pyridazine, 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-indole-5-amine, 1-(4 -aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-indol-6-amine, 3,5-diaminobenzoic acid, cholestyloxy-3, 5-cholestyloxy-3,5-diaminobenzene, cholesteneoxy-3,5-diaminobenzene, cholestyloxy-2,4-diaminobenzene, cholestene oxygen Base-2,4-diaminobenzene, cholesteryl 3,5-diaminobenzoic acid, cholesteryl 3,5-diaminobenzoic acid, lanolin 3,5-diaminobenzoic acid Alkyl, 3,6-bis(4-aminobenzylideneoxy)cholestane, 3,6-bis(4-aminophenoxy)cholestane, 4-(4'-trifluoromethyl Oxybenzophenoxy)cyclohexyl-3,5-diaminobenzoate, 4-(4'-trifluoromethylbenzyloxy)cyclohexyl-3,5-diaminobenzene Formate, 1,1-bis(4-((aminophenyl)methyl)phenyl)-4-butylcyclohexane, 1,1-bis(4-((aminophenyl)) Phenyl)-4-heptyl Cyclohexane, 1,1-bis(4-((aminophenoxy)methyl)phenyl)-4-heptylcyclohexane, 1,1-bis(4-((aminophenyl)) Methyl)phenyl)-4-(4-heptylcyclohexyl)cyclohexane, 2,4-diamino-N,N-diallylaniline, 4-aminobenzylamine, 3-amine Benzylamine, 1,3-diamino-4-octadecyloxybenzene, 3-(3,5-diaminobenzylideneoxy)cholestane, 3,6-bis(4- Aminobenzimidyloxy)cholesterane, a compound represented by the following formula (D-1), and the like,

(In the formula (D-1), X ^I and X ^II are each independently a single bond, -O-, -COO- or -OCO-, and R ^I and R ^II are each independently an alkanediyl group having 1 to 3 carbon atoms. a is 0 or 1, b is an integer of 0 to 2, c is an integer of 1 to 20, and n is 0 or 1. Among them, a and b are not 0), and a diamine-based organodecane can be exemplified. A 1,3-bis(3-aminopropyl)-tetramethyldioxane or the like; in addition to the above, a diamine disclosed in Japanese Laid-Open Patent Publication No. 2010-97188 can be used.

The divalent group represented by "-X ^I -(R ^I -X ^II ) _n -" in the formula (D-1) is preferably an alkanediyl group having 1 to 3 carbon atoms, *-O-, *-COO - or *-OC ₂ H ₄ -O- (wherein the bond with "*" is bonded to the diaminophenyl group).

Specific examples of the group "-C _c H _2c+1 " include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, and the like. N-decyl, n-decyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, N-nonadecyl, n-icosyl and the like. The two amine groups in the diaminophenyl group are preferably located at the 2,4-position or the 3,5-position relative to the other groups.

Specific examples of the compound represented by the formula (D-1) include a compound represented by the following formula (D-1-1) to formula (D-1-5).

Further, the diamine compound for synthesizing poly-proline may be used alone or in combination of two or more kinds.

Further, the diamine compound for synthesizing the poly-proline of the present invention preferably contains a diamine (d-1) having a carboxyl group. By using the diamine (d-1), polylysine having a carboxyl group in a side chain can be synthesized. By including such a carboxyl group-containing polyamine acid (carboxyl group-containing polymer (A)) in the liquid crystal alignment agent together with the compound (b) represented by the formula (1), the following effects can be suitably obtained. When the liquid crystal alignment agent is applied onto the substrate, the region where the film thickness is defective can be narrowed as much as possible at the end portion of the coating region.

The diamine (d-1) is not particularly limited as long as it has at least one carboxyl group and two primary amino groups, and an aliphatic diamine, an alicyclic diamine, an aromatic diamine, or a diamine organic hydrazine can be used. Oxytomane, etc. Among these diamines, the diamine (d-1) is preferably an aromatic diamine, and it is particularly preferred that a carboxyl group is bonded to the aromatic ring. Further, the number of carboxyl groups in the molecule of the diamine (d-1) is preferably an integer of 1 to 4, and more preferably 1 or 2.

Preferable specific examples of the diamine (d-1) contained in the liquid crystal alignment agent of the present invention include a compound represented by the following formula (d1-1) and a compound represented by the formula (d1-2). .

(In the formula (d1-1) and the formula (d1-2), R ^a is a halogen atom, an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms; and Z ¹ is a single bond or an oxygen atom or The alkanediyl group having a carbon number of 1 to 3. The e and f are each independently an integer of 1 or 2, and g and h are each independently an integer of 0 to 2, and s and t are each independently 0 to 2 satisfying s+t=2. In the formula (d1-2), e+g+s≦5 and f+h+t≦5. When g and h are 2, a plurality of R ^a independently have the definition).

The halogen atom of R ^a in the formula (d1-1) and the formula (d1-2) may, for example, be a fluorine atom, a chlorine atom or a bromine atom. Further, examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group and a fluorenyl group, and these groups may be a linear chain. The shape can also be branched. Examples of the alkoxy group having 1 to 10 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group, and an anthracene group. Oxy groups, these groups may be linear or branched.

Examples of the alkanediyl group having 1 to 3 carbon atoms of Z ¹ include a methylene group, an ethylidene group, a trimethylene group, and a propyl group.

g and h are preferably 0 or 1, more preferably 0.

Specific examples of the diamine (d-1) include, for example, 3,5-diaminobenzoic acid and 2,4-diaminobenzoic acid, and the compound represented by the formula (d1-1). , 5-diaminobenzoic acid, etc.; the compound represented by the formula (d1-2) includes, for example, 4,4′-diaminobiphenyl-3,3′-dicarboxylic acid, 4, 4 '-Diaminobiphenyl-2,2'-dicarboxylic acid, 3,3'-diaminobiphenyl-4,4'-dicarboxylic acid, 3,3'-diaminobiphenyl-2, 4'-dicarboxylic acid, 4,4'-diaminodiphenylmethane-3,3'-dicarboxylic acid, 4,4'-diaminobiphenyl-3-carboxylic acid, 4,4'- Diaminodiphenylmethane-3-carboxylic acid, 4,4'-diaminodiphenylethane-3,3'-dicarboxylic acid, 4,4'-di Aminodiphenylethane-3-carboxylic acid, 4,4'-diaminodiphenyl ether-3,3'-dicarboxylic acid, 4,4'-diaminodiphenyl ether-3- Carboxylic acid, etc.

From the viewpoint of appropriately suppressing the film thickness defect at the end portion of the coating region, the ratio of the diamine (d-1) is preferably relative to the total amount of the diamine compound for synthesizing the polyamic acid. It is set to 5 mol% or more, and more preferably set to 10 mol% or more. In addition, the upper limit of the ratio of the diamine (d-1) is not particularly limited, and is preferably 90 mol% or less, and more preferably 80 mol, based on the total amount of the diamine compound used in the synthesis. %the following. The diamine compound used in the synthesis of the poly-proline acid of the present invention preferably contains 30 mol% or more of an aromatic diamine, more preferably 50 mol% or more of an aromatic diamine, and more preferably It is an aromatic diamine containing 80 mol% or more.

[Molecular weight regulator]

In the case of synthesizing polyamic acid, a terminal-modified polymer may be synthesized by using an appropriate molecular weight modifier together with a tetracarboxylic dianhydride and a diamine compound as described above. By setting the polymer of the terminal modification type, the coating property (printability) of the liquid crystal alignment agent can be further improved without impairing the effects of the present invention.

Examples of the molecular weight modifier include an acid monoanhydride, a monoamine compound, and a monoisocyanate compound. Specific examples of the molecular weight modifiers include, for example, maleic anhydride, phthalic anhydride, itaconic anhydride, n-decyl succinic anhydride, n-dodecyl succinic anhydride, n-tetradecyl group. Succinic anhydride, n-hexadecyl succinic anhydride, etc.; monoamine compounds include, for example, aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-dodecyl Amine, n-octadecyl An amine or the like; a monoisocyanate compound may, for example, be phenyl isocyanate or naphthyl isocyanate.

The use ratio of the molecular weight modifier is preferably 20 parts by weight or less, and more preferably 10 parts by weight or less, based on 100 parts by weight of the total amount of the tetracarboxylic dianhydride and the diamine to be used.

<Synthesis of polylysine>

The ratio of use of the tetracarboxylic dianhydride to the diamine compound in the synthesis reaction of the polyaminic acid to be used in the present invention is preferably an acid anhydride group of the tetracarboxylic dianhydride with respect to 1 equivalent of the amine group of the diamine compound. The ratio of 0.2 equivalent to 2 equivalents is more preferably the ratio of the acid anhydride group of the tetracarboxylic dianhydride to 0.3 equivalent to 1.2 equivalent. Further, the synthesis reaction of polyproline is preferably carried out in an organic solvent. The reaction temperature at this time is preferably -20 ° C to 150 ° C, more preferably 0 ° C to 100 ° C. Further, the reaction time is preferably from 0.1 to 24 hours, more preferably from 0.5 to 12 hours.

Here, examples of the organic solvent used in the reaction include an aprotic polar solvent, a phenol solvent, an alcohol, a ketone, an ester, an ether, a halogenated hydrocarbon, and a hydrocarbon. Specific examples of the organic solvent include, for example, N-methyl-2-pyrrolidone and 1,3-dimethyl-2-imidazolidinone (1,3-dimethyl-2-imidazolidinone). ), N-ethyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl hydrazine, γ-butyrolactone, tetramethylurea, Hexamethylphosphoric amide or the like; examples of the phenol solvent include phenol, m-cresol, xylenol, halogenated phenol, and the like; Examples of the alcohol include methanol, ethanol, isopropanol, cyclohexanol, ethylene glycol monomethyl ether, ethylene glycol, propylene glycol, 1,4-butanediol, and triethylene glycol; and ketones include, for example, : acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.; esters include, for example, ethyl lactate, butyl lactate, methyl acetate, ethyl acetate, butyl acetate, methoxy group. Methyl propionate, ethyl ethoxypropionate, diethyl oxalate, diethyl malonate, isoamyl propionate, isoamyl isobutyrate, etc.; ethers include, for example, diethyl ether and ethylene Alcohol methyl ether, ethylene glycol ether, ethylene glycol n-propyl ether, ethylene glycol isopropyl 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, diisoamyl ether Examples of the halogenated hydrocarbons include dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene, and the like; and hydrocarbons include, for example, :hexane, g , Octane, benzene, toluene, xylene and the like.

Among these organic solvents, it is preferred to use one or more selected from the group consisting of an aprotic polar solvent and a phenolic solvent (the first group of organic solvents), or selected from the first group of organic solvents. One or more of a mixture of one or more selected from the group consisting of alcohols, ketones, esters, ethers, halogenated hydrocarbons, and hydrocarbons (the second group of organic solvents). In the latter case, the ratio of the organic solvent of the second group is preferably 50% by weight or less, more preferably 40% by weight or less, based on the total amount of the organic solvent of the first group and the organic solvent of the second group. It is preferably 30% by weight or less. Further, the amount (α) of the organic solvent used is preferably set to the following amount. In other words, the total amount (β) of the tetracarboxylic dianhydride and the diamine is 0.1% by weight to 50% by weight based on the total amount (α + β) of the reaction solution.

As described above, a reaction solution obtained by dissolving polylysine can be obtained. The reaction solution may be directly used for preparing a liquid crystal alignment agent, or may be separated from the polylysine contained in the reaction solution to prepare a liquid crystal alignment agent, or the separated polyamic acid may be purified and then used for preparing a liquid crystal. An aligning agent. In the case where polylysine is dehydrated and closed to form a polyimine, the reaction solution may be directly supplied to a dehydration ring-closure reaction, or the polylysine contained in the reaction solution may be separated and then subjected to dehydration. The ring closure reaction, or the isolated polyamic acid can also be purified for dehydration ring closure reaction. The separation and purification of polylysine can be carried out according to well-known methods.

<Polymer (A): Polyamide)

The polyglycolate (hereinafter also referred to as polyphthalate (A)) as the polymer (A) can be obtained, for example, by the following method: [I] a polycondensation obtained by the synthesis reaction a method for synthesizing a polyphthalate by reacting a proline (A) with a hydroxyl group-containing compound, a halide, an epoxy group-containing compound, or the like; [II] reacting a tetracarboxylic acid diester with a diamine compound Method; [III] A method of reacting a tetracarboxylic acid diester dihalide with a diamine compound.

Here, examples of the hydroxyl group-containing compound used in the method [I] include alcohols such as methanol, ethanol, and propanol; and phenols such as phenol and cresol. Further, examples of the halide include methyl bromide, ethyl bromide, stearyl bromide, methyl chloride, stearyl chloride, 1,1,1-trifluoro-2-iodoethane, and the like, and epoxy group-containing compounds. For example, propylene oxide etc. are mentioned. The tetracarboxylic acid diester used in the method [II] can be used to make a tetracarboxylic acid by using the alcohol The dianhydride is obtained by ring opening. Further, the tetracarboxylic acid diester dihalide used in the method [III] can be obtained by reacting a tetracarboxylic acid diester obtained as described above with a suitable chlorinating agent such as sulfinium chloride. The diamine compound used in the method [II] and the method [III] may, for example, be a compound exemplified as a diamine for synthesizing the polyaminic acid. Further, the polyphthalate (A) may have only a phthalate structure, or may be a partial ester compound in which a valeric acid structure and a phthalate structure coexist.

<Polymer (A): Polyimine)

The polyimine which is the polymer (A) contained in the liquid crystal alignment agent of the present invention can be obtained by subjecting the polylysine synthesized as described above to dehydration ring closure and subjecting to ruthenium iodization.

The polyimine may be a complete quinone imide formed by dehydration ring closure of all of the proline structures of the polyglycolic acid as a precursor thereof, or may be a proline structure and a proline. A part of the ester structure is dehydrated and closed, and at least one of a proline structure and a phthalate structure, and a partial quinone imide which coexists with the quinone ring structure. From the viewpoint of improving the voltage holding ratio, the polyimine of the present invention preferably has a sulfhydrylation ratio of 30% or more, more preferably 40% to 99%, still more preferably 50% to 99%. The ruthenium imidization ratio is a percentage of the number of ruthenium ring structures in the polyimine, the number of guanamine structures, the number of phthalate structures, and the number of quinone ring structures. The proportion of the quantity. Here, a part of the quinone ring may also be an isoindole ring.

The dehydration ring closure of polylysine is preferably carried out by a method of heating polylysine or by dissolving polylysine in an organic solvent. A dehydrating agent and a dehydration ring-closure catalyst are added to the solution, and heating is carried out as needed. Among them, it is preferred to use the latter method.

In the method of adding a dehydrating agent and a dehydration ring-closure catalyst to a solution of poly-proline to carry out hydrazine imidation, for example, an acid anhydride such as acetic anhydride, propionic anhydride or trifluoroacetic anhydride can be used. The amount of the dehydrating agent used is preferably set to 0.01 mol to 20 mol relative to the proline structure of poly-proline. As the dehydration ring-closing catalyst, for example, a tertiary amine such as pyridine, trimethylpyridine, lutidine or triethylamine can be used. The amount of the dehydration ring-closing catalyst to be used is preferably set to 0.01 mol to 10 mol with respect to the dehydrating agent used. The organic solvent used in the dehydration ring-closure reaction may, for example, be an organic solvent exemplified as an organic solvent for synthesizing polyamic acid. The reaction temperature of the dehydration ring closure reaction is preferably from 0 ° C to 180 ° C, more preferably from 10 ° C to 150 ° C. The reaction time is preferably from 1.0 to 120 hours, more preferably from 2.0 to 30 hours.

A reaction solution containing polyimine can be obtained in this manner. The reaction solution may be directly used for preparing a liquid crystal alignment agent, or may be used for preparing a liquid crystal alignment agent after removing a dehydrating agent and a dehydration ring-closing catalyst from the reaction solution, or may be used for preparing a liquid crystal alignment agent after separating the polyfluorene imide, or The isolated polyimine can also be purified and used to prepare a liquid crystal alignment agent. These purification operations can be carried out in accordance with well-known methods.

<Solid viscosity and weight average molecular weight of polymer (A)>

The polylysine, polyphthalate and polyimine obtained as above are preferably 10 mPa when they are made into a solution having a concentration of 10% by weight. s~800mPa. The solution viscosity of s is more preferably 15 mPa. s~500mPa. s solution Viscosity. Further, the solution viscosity (mPa.s) of the polymer is prepared by using an E-type rotational viscometer for a good solvent (for example, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.) using the polymer. The concentration of the 10% by weight polymer solution was measured at 25 ° C. Further, the polyamic acid, polyphthalate, and polyimine contained in the liquid crystal alignment agent of the present invention are converted to polystyrene equivalent weight by gel permeation chromatography (GPC). The average molecular weight (Mw) is preferably from 500 to 100,000, more preferably from 1,000 to 50,000.

<Other ingredients>

The liquid crystal alignment agent of the present invention may contain other components as needed. Examples of the other component include a polymer other than the polymer (A), a compound having at least one epoxy group in the molecule (hereinafter referred to as "epoxy group-containing compound"), a functional decane compound, and the like. .

<Other polymers>

The other polymers can be used to improve solution properties or electrical properties. Examples of the other polymer include polyorganosiloxane, polyester, polyamine, cellulose derivative, polyacetal, polystyrene derivative, and poly(styrene-phenylmaleimide). Derivatives, poly(meth)acrylates, and the like.

In the case where the other polymer is added to the liquid crystal alignment agent, the compounding ratio of the other polymer is preferably 50 parts by weight or less, more preferably 0.1 part by weight, based on 100 parts by weight of the total amount of the polymer contained in the liquid crystal alignment agent. ~40 parts by weight, further preferably 0.1 parts by weight to 30 parts by weight.

<epoxy group-containing compound>

The epoxy group-containing compound can be used to improve the adhesion or electrical properties of the liquid crystal alignment film to the surface of the substrate. Examples of such an epoxy group-containing compound include the following compounds as preferred compounds: 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, trimethylolpropane triglycidyl ether, 2,2-dibromopentane Glycol diglycidyl ether, N,N,N',N'-tetraglycidyl-m-xylylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane , N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, N,N-diglycidyl-benzylamine, N,N-diglycidyl- Aminomethylcyclohexane, N,N-diglycidyl-cyclohexylamine and the like. In addition to the above, examples of the epoxy group-containing compound include the epoxy group-containing polyorganosiloxane which is described in International Publication No. 2009/096598.

In the case where the epoxy compound is added to the liquid crystal alignment agent, the compounding ratio of these epoxy compounds is preferably 40 parts by weight or less, more preferably 0.1% by weight based on 100 parts by weight of the total amount of the polymer contained in the liquid crystal alignment agent. Parts by weight to 30 parts by weight.

<Functional decane compound>

The functional decane compound can be used in order to improve the printability of the liquid crystal alignment agent. Examples of such a functional decane compound include 3-aminopropyltrimethoxydecane, 3-aminopropyltriethoxydecane, 2-aminopropyltrimethoxydecane, and 2-aminopropylpropane. Triethoxy decane, N-(2-aminoethyl)-3-aminopropyltrimethoxydecane, N-(2-aminoethyl)-3-aminopropylmethyl dimethyl Oxydecane, 3-guanidinopropyl Trimethoxydecane, 3-ureidopropylpropyltriethoxydecane, N-ethoxycarbonyl-3-aminopropyltrimethoxydecane, N-triethoxydecylpropyltriethylenetriamine , 10-trimethoxydecyl-1,4,7-triazadecane, 9-trimethoxydecyl-3,6-diazadecyl acetate, 9-trimethoxydecyl- 3,6-diazepine methyl, N-benzyl-3-aminopropyltrimethoxydecane, N-phenyl-3-aminopropyltrimethoxydecane, glycidoxymethyl Trimethoxy decane, 2-glycidoxyethyl trimethoxy decane, 3-glycidoxypropyl trimethoxy decane, and the like.

In the case where the functional decane compound is added to the liquid crystal alignment agent, the compounding ratio of these functional decane compounds is preferably 2 parts by weight or less, based on 100 parts by weight of the total amount of the polymer contained in the liquid crystal alignment agent. It is preferably 0.02 parts by weight to 0.2 parts by weight.

Further, as the other component, in addition to the compound, a compound having at least one oxetanyl group in the molecule, an antioxidant, or the like can be used.

<solvent>

In the liquid crystal alignment agent of the present invention, it is preferred that the polymer (A) and other components optionally arbitrarily formulated are dissolved in an organic solvent. The solvent for preparing the liquid crystal alignment agent of the present invention may contain an organic solvent (hereinafter also referred to as a first solvent (a)) which can dissolve the polymer (A), and specific examples thereof include N-methyl group. -2-pyrrolidone, N-ethyl-2-pyrrolidone, N-pentyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N,N-dimethylformamide, N,N - dimethyl acetamide, 4-hydroxy-4-methyl-2-pentanone, 1,3-dimethyl-1-imidazolidinone, 3-butoxy-N,N-dimethylpropane Indoleamine, 3-hexyloxy-N,N-dimethylpropanedecylamine, and the like.

In addition, the liquid crystal alignment agent of the present invention contains the compound (b) represented by the following formula (1) as a solvent.

[Chemical 5] HO-R ¹ -OH (1)

In the formula (1), R ¹ is a divalent chain hydrocarbon group or an alicyclic hydrocarbon group having 2 to 10 carbon atoms, or contains "-O-" between the carbon-carbon bond of the chain hydrocarbon group or the alicyclic hydrocarbon group. Divalent base.

In addition, the chain hydrocarbon group in the present specification means a saturated hydrocarbon group and an unsaturated hydrocarbon group which do not contain a cyclic structure in the main chain but are composed only of a chain structure. Among them, both linear hydrocarbon groups and branched hydrocarbon groups are included. Further, the alicyclic hydrocarbon group means a hydrocarbon group which contains only an alicyclic hydrocarbon structure and does not contain an aromatic ring structure as a ring structure. However, it is not necessary to constitute only the alicyclic hydrocarbon structure, but also a hydrocarbon group partially having a chain structure.

With respect to the above formula (1), examples of the divalent chain hydrocarbon group having 2 to 10 carbon atoms of R ¹ include an exoethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, and a heptyl group. The group may be linear or branched, such as octyl, sulfhydryl, fluorenyl, propylene, butenyl, and pentenyl. Examples of the divalent alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutene butyl group, a cyclopentylene group, a cyclohexylene group, a cyclohexene group, an extended borneol group, an adenantyl group, and the like. Further, R ¹ may be a divalent group having "-O-" between at least one of the carbon-carbon bonds of the divalent chain hydrocarbon group or the alicyclic hydrocarbon group. Among them, R ¹ is preferably a group having a "-O-" group between a carbon-carbon bond of a divalent chain hydrocarbon group or a divalent chain hydrocarbon group.

R ¹ is preferably a group having 3 to 7 carbon atoms, more preferably a group having 4 to 6 carbon atoms.

Specific examples of the compound (b) include ethylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, 1,2-propylene glycol, and 1,3-propanediol. 2-butanediol, 1,3-butanediol, 2,3-butanediol, 1,4-butanediol, 2-butene-1,4-diol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 1,5-pentanediol, 2,3-pentanediol, 2,4-pentanediol, 1,2-hexanediol, 1, 3-hexanediol, 1,4-hexanediol, 1,5-hexanediol, 1,6-hexanediol, 2,3-hexanediol, 2,4-hexanediol, 2,5- Hexanediol, 3,4-hexanediol, 2-methyl-2,4-pentanediol, 1,2-heptanediol, 2,3-heptanediol, 3,4-heptanediol, 1 , 3-heptanediol, 2,4-heptanediol, 3,5-heptanediol, 1,4-heptanediol, 2,5-heptanediol, 1,5-heptanediol, 2,6 - heptanediol, 1,6-heptanediol, 1,7-heptanediol, 2-ethyl-1,3-hexanediol, 1,2-decanediol, 1,9-nonanediol, 8-methyl-1,8-nonanediol, 1,2-cyclopentanediol, 1,3-cyclopentanediol, 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1 , 4-cyclohexanediol, and the like. Further, the compound (b) may be used alone or in combination of two or more kinds.

Further, among the compounds, the compound (b) is particularly preferably selected from the group consisting of diethylene glycol, dipropylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, and , 3-butanediol, 2,3-butanediol, 1,4-butanediol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 1,5 - pentanediol, 2,3-pentanediol, 2,4-pentanediol, 1,2-hexanediol, 1,3-hexanediol, 1,4-hexanediol, 1,5- Hexanediol, 1,6-hexanediol, 2,3-hexanediol, 2,4-hexanediol, 2,5-hexanediol, 3,4-hexanediol, and 2-methyl-2 , 4-pentanediol At least one of the groups.

In order to improve the coating property of the liquid crystal alignment agent, the solvent (for the first solvent (a) and the solvent (c) other than the compound (b) may be used as the solvent for preparing the liquid crystal alignment agent of the present invention. Examples of the other solvent (c) include ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, and ethylene glycol. Alcohol ether, ethylene glycol n-propyl ether, ethylene glycol isopropyl 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, dipropylene glycol single Methyl ether, diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, diisoamyl ether, ethyl carbonate, propyl carbonate, propylene glycol diacetate, diacetone alcohol, acetamidine, Ethyl acetate and the like. Further, the other solvent (c) may be used alone or in combination of two or more.

The liquid crystal alignment agent of the present invention contains, as a solvent, the compound (b) represented by the above formula (1) in an amount of from 1% by weight to 60% by weight based on the total amount of the solvent contained in the liquid crystal alignment agent. When the content ratio is less than 1% by weight, the effect of suppressing the film thickness of the end portion of the coating region is not properly obtained, and it is difficult to obtain an effect of appropriately improving the viscosity of the liquid crystal alignment agent, and the coating property tends to be lowered. . On the other hand, when the content ratio exceeds 60% by weight, the viscosity of the liquid crystal alignment agent becomes too high and the coatability is lowered. The lower limit of the content ratio of the compound (b) is preferably 3% by weight or more, more preferably 5% by weight or more, and still more preferably 10% by weight or more based on the total amount of the solvent. Further, the upper limit value is preferably 50% by weight or less based on the total amount of the solvent. It is more preferably 40% by weight or less, still more preferably 30% by weight or less.

In addition, from the viewpoint of uniformly dissolving the polymer component and appropriately suppressing precipitation of the polymer during substrate printing, the content of the first solvent (a) is preferably based on the total amount of the solvent contained in the liquid crystal alignment agent. It is set to 10% by weight to 98% by weight. The lower limit of the content ratio of the first solvent (a) is more preferably 20% by weight or more, and still more preferably 30% by weight or more. In addition, from the viewpoint of appropriately obtaining the effect of adding the compound (b), the upper limit of the content ratio is more preferably 95% by weight or less, still more preferably 90% by weight or less, and particularly preferably It is set to 85% by weight or less.

From the viewpoint of suppressing the precipitation of the polymer (A) and improving the coatability of the liquid crystal alignment agent, the content of the other solvent (c) is preferably set to 1% by weight based on the total amount of the solvent contained in the liquid crystal alignment agent. ~60% by weight. The lower limit of the liquid crystal alignment agent is more preferably 2% by weight or more, and even more preferably 5% by weight or more, from the viewpoint of improving the coating property of the liquid crystal alignment agent. In addition, from the viewpoint of suppressing the precipitation of the polymer (A), the upper limit is more preferably 50% by weight or less, and still more preferably 40% by weight or less based on the total amount of the solvent.

The solid content concentration of the liquid crystal alignment agent of the present invention (the ratio of the total weight of the components other than the solvent of the liquid crystal alignment agent to the total weight of the liquid crystal alignment agent) is appropriately selected in consideration of viscosity, volatility, etc., and is preferably 0.1 weight. Range of %~10% by weight. That is, the liquid crystal alignment agent of the present invention is applied onto the surface of the substrate as will be described later, preferably by heating, thereby forming a coating film or a film as a liquid crystal alignment film. In the case of a coating film of a liquid crystal alignment film, in the case where the solid content concentration is less than 0.1% by weight, the film thickness of the coating film is too small, and it is difficult to obtain a favorable liquid crystal alignment film. On the other hand, when the solid content concentration exceeds 10% by weight, the film thickness of the coating film becomes too large, and it is difficult to obtain a favorable liquid crystal alignment film, and the viscosity of the liquid crystal alignment agent increases, and the coating property is deteriorated.

The range of the particularly preferable solid content concentration differs depending on the method used when the liquid crystal alignment agent is coated on the substrate. For example, in the case of using a spin coating method, it is particularly preferable that the solid content concentration is in the range of 1.5% by weight to 4.5% by weight. In the case of using the offset printing method, it is particularly preferable to set the solid content concentration to a range of 3% by weight to 9% by weight, thereby setting the solution viscosity to 12 mPa. s~50mPa. The scope of s. In the case of using the inkjet method, it is particularly preferable to set the solid content concentration to a range of 1% by weight to 5% by weight, thereby setting the solution viscosity to 3 mPa. s~15mPa. The scope of s. When coating a pair of substrates which are disposed to face each other with a predetermined gap by capillary action, it is preferable to set the solid content concentration to a range of 0.1% by weight to 2.0% by weight, thereby setting the solution viscosity to 2 mPa. . s~10mPa. The scope of s. The temperature at which the liquid crystal alignment agent of the present invention is prepared is preferably 10 ° C to 50 ° C, more preferably 20 ° C to 30 ° C.

<Liquid alignment film and liquid crystal display element>

The liquid crystal alignment film of the present invention is formed using a liquid crystal alignment agent prepared as described above. The method for producing the liquid crystal alignment film is, for example, a conventional method in which a liquid crystal alignment agent is applied to a pair of substrates to form a coating film (first film formation method), and a pair of substrates are disposed to face each other and then coated. Method (second film shape Into the method) and so on. Further, the liquid crystal display element of the present invention comprises a liquid crystal alignment film formed using the liquid crystal alignment agent of the present invention. The driving mode of the liquid crystal display element to which the present invention is applied is not particularly limited, and can be applied to TN type, STN type, IPS type, FFS type, VA type, Multi-Domain Vertical Alignment (MVA) type, PSA type. And other drive modes.

(Production of Liquid Crystal Display Element Using First Film Forming Method)

When the liquid crystal alignment film of the present invention is produced by the first film formation method, the liquid crystal display device of the present invention can be produced, for example, by the following steps (1) to (3). In the step (1), the use of the substrate differs depending on the driving mode required. Step (2) and step (3) are the same in the case of each drive mode.

[Step (1): Formation of coating film]

First, the liquid crystal alignment agent of the present invention is applied onto a substrate, and then the substrate is heated to form a coating film on the substrate.

(1-1) When manufacturing a TN type, STN type, VA type, MVA type or PSA type liquid crystal display element, two substrates provided with a patterned transparent conductive film are used as a pair of substrates, The liquid crystal alignment agent of the present invention is applied to the surface of each of the substrates on which the transparent conductive film is formed. For the substrate, for example, glass such as float glass or soda glass can be used; including polyethylene terephthalate, polybutylene terephthalate, polyether oxime, polycarbonate, and poly A transparent substrate of plastic such as (alicyclic olefin). The transparent conductive film provided on one surface of the substrate may be a Neisser (NESA) film containing tin oxide (SnO ₂ ) (registered trademark of PPG, USA), and contains indium oxide-tin oxide (In ₂ O ₃ -SnO ₂ ). Indium Tin Oxide (ITO) film, etc. In order to obtain a patterned transparent conductive film, for example, a method of forming a pattern by photolithography after forming a transparent conductive film having no pattern, and a mask having a desired pattern when forming a transparent conductive film may be used. (mask) method, etc.

The coating method of the liquid crystal alignment agent of the present invention is not particularly limited, and it is preferably carried out by an offset printing method, a spin coating method, a roll coating method or an inkjet method. In particular, the liquid crystal alignment agent of the present invention can suitably obtain an effect of narrowing a region where the film thickness is poor as possible at the end portion of the coating region by coating for the inkjet method, thereby realizing a narrow liquid crystal panel. Marginalized. 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 functional titanium compound may be previously applied to the surface on which the coating film is formed on the surface of the substrate. Pre-processing.

After the liquid crystal alignment agent is applied, in order to prevent dripping of the applied alignment agent or the like, it is preferred to carry out preheating (prebaking). The prebaking temperature is preferably 30 ° C to 200 ° C, more preferably 40 ° C to 150 ° C, and particularly preferably 40 ° C to 100 ° C. The prebaking time is preferably from 0.25 minutes to 10 minutes, more preferably from 0.5 minutes to 5 minutes. Thereafter, in order to completely remove the solvent, a calcination (post-baking) step is carried out in order to thermally imidize the proline structure or the guanamine structure which is present in the polymer as needed. The calcination temperature (post-baking temperature) at this time is preferably 80 ° C to 300 ° C, more preferably 120 ° C to 250 ° C. The post-baking time is preferably from 5 minutes to 200 minutes, more preferably from 10 minutes to 100 minutes. As described above, the film thickness of the formed film is preferably 0.001 μm to 1 μm, and more preferably 0.005 μm to 0.5 μm.

(1-2) In the case of manufacturing an IPS type or FFS type liquid crystal display element, an electrode-formed surface of a substrate provided with an electrode including a transparent conductive film or a metal film patterned into a comb-tooth type The liquid crystal alignment agent of the present invention is applied to one surface of the opposite substrate on which the electrode is not provided, and then each coated surface is heated to form a coating film. Material of the substrate and the transparent conductive film used at this time, a coating method, heating conditions after coating, a method of patterning a transparent conductive film or a metal film, pretreatment of a substrate, and a preferred film thickness of the formed coating film The description (1-1) is the same. As the metal film, for example, a film containing a metal such as chromium can be used.

In any of the above (1-1) and (1-2), after the liquid crystal alignment agent is applied onto the substrate, the organic solvent is removed, thereby forming a coating film as a liquid crystal alignment film or forming a liquid crystal alignment film. Coating film. In this case, in the case where the polymer contained in the liquid crystal alignment agent of the present invention is a polyamic acid, a polyphthalate or a ruthenium imidized polymer having a quinone ring structure and a proline structure. Further, a dehydration ring-closure reaction may be carried out by further heating after forming a coating film to prepare a coating film which is further imidized.

[Step (2): Friction treatment]

In the case of manufacturing a liquid crystal display element of a TN type, an STN type, an IPS type or an FFS type, a rubbing treatment for rubbing a coating film formed in the step (1) in a certain direction by a roll, which is wound on a roll A cloth containing fibers such as nylon, rayon, cotton, and the like. Thereby, the alignment ability of the liquid crystal molecules is imparted to the coating film to become a liquid crystal alignment film. On the other hand, in the case of manufacturing a VA type liquid crystal display element, the coating film formed in the step (1) can be directly used as a liquid crystal alignment film, or the coating film can be used. Apply friction treatment. Further, the liquid crystal alignment film after the rubbing treatment may be further subjected to the following treatment so that the liquid crystal alignment film has different liquid crystal alignment ability depending on the viewing area, that is, the liquid crystal alignment film is irradiated by irradiating a part of the liquid crystal alignment film with ultraviolet rays. The treatment of the pretilt angle change in a part of the region; or after the resist film is formed on a part of the surface of the liquid crystal alignment film, the rubbing treatment is performed in a direction different from the previous rubbing treatment, and then the resist film is removed. In this case, the visual field characteristics of the obtained liquid crystal display element can be improved.

In the case of producing a PSA liquid crystal display device, the following step (3) may be carried out by directly using the coating film formed in the above step (1), or may be carried out by a simple method in order to control the tilt of the liquid crystal molecules. The alignment is divided and the weak rubbing treatment is performed.

[Step (3): Construction of liquid crystal cell]

(3-1) Two substrates in which the liquid crystal alignment film was formed as described above were prepared, and liquid crystals were placed between the two substrates arranged in the opposite direction to manufacture a liquid crystal cell. When manufacturing a liquid crystal cell, the following two methods are mentioned, for example. First, the first method is a method that has been known for a long time. In this method, first, the two substrates are arranged to face each other with a gap (cell gap) so that the liquid crystal alignment films face each other, and the peripheral portions of the two substrates are bonded together using a sealant, and are divided by the surface of the substrate and the sealant. After filling the liquid crystal into the cell gap, the injection hole is sealed, thereby manufacturing a liquid crystal cell. In addition, the second method is a method called a One Drop Fill (ODF) method. In this method, for example, an ultraviolet light-curable sealing material is applied to a predetermined portion of one of the two substrates on which the liquid crystal alignment film is formed, and further liquid is applied. After the liquid crystal is dropped onto a predetermined portion of the film surface, the liquid crystal is instilled, and the other substrate is bonded in such a manner that the liquid crystal alignment film faces each other. Then, the liquid crystal is pushed and spread over the entire surface of the substrate, and then the entire surface of the substrate is irradiated with ultraviolet light to harden the sealant, thereby manufacturing a liquid crystal cell. In any of the methods, it is preferred that the liquid crystal cell produced as described above is further heated until the liquid crystal used is in the in-phase temperature, and then slowly cooled to room temperature, thereby liquid crystal The flow alignment at the time of filling is removed.

As the sealant, for example, an epoxy resin containing a curing agent and an alumina ball as a spacer can be used. Further, the liquid crystal may be a nematic liquid crystal or a smectic liquid crystal. Among them, a nematic liquid crystal is preferable, and for example, a Schiff base liquid crystal, an oxidized azo liquid crystal, a biphenyl liquid crystal, or a phenylcyclohexane can be used. Liquid crystal, ester liquid crystal, terphenyl liquid crystal, biphenyl cyclohexane liquid crystal, pyrimidine liquid crystal, dioxane liquid crystal, bicyclooctane liquid crystal, cetane liquid crystal, or the like. Further, it is also possible to use a liquid crystal such as chlorinated cholesterol, cholesteryl citrate or cholesteryl carbonate in the liquid crystal; for example, the trade names "C-15" and "CB-15" (Merck) A chiral agent sold by the company; a ferroelectric liquid crystal such as p-oxybenzylidene-p-amino-2-methylbutylcinnamate.

(3-2) In the case of producing a PSA type liquid crystal display device, a liquid crystal cell is constructed in the same manner as in the above (3-1) except that a photopolymerizable compound is injected or dropped together with the liquid crystal. Thereafter, the liquid crystal cell is irradiated with light in a state where a voltage is applied between the conductive films of the pair of substrates. The voltage applied here can be set, for example, to 5 V to 50 V DC or AC. Further, as the irradiation light, for example, ultraviolet rays and visible rays containing light having a wavelength of 150 nm to 800 nm can be used, and ultraviolet rays containing light having a wavelength of 300 nm to 400 nm are preferable. As the light source for illuminating light, for example, a low pressure mercury lamp, a high pressure mercury lamp, a xenon lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, an excimer laser or the like can be used. Further, the ultraviolet light of the preferred wavelength range can be obtained by a method in which a light source is used in combination with, for example, a filter, a diffraction grating, or the like. The irradiation amount of light is preferably 1,000 J/m ² or more and less than 200,000 J/m ² , and more preferably 1,000 J/m ² to 100,000 J/m ² .

Then, a polarizing plate is attached to the outer surface of the liquid crystal cell, whereby the liquid crystal display element of the present invention can be obtained. The polarizing plate which is bonded to the outer surface of the liquid crystal cell is a polarizing film called "H film" which is formed by stretching a polyvinyl alcohol on one side and absorbing iodine by using a cellulose acetate protective film. A polarizing plate or a polarizing plate containing the H film itself. Further, in the case where the coating film is subjected to the rubbing treatment, the two substrates are arranged such that the rubbing directions of the respective coating films are at a predetermined angle, for example, orthogonal or anti-parallel.

(Production of Liquid Crystal Display Element Using Second Film Forming Method)

The second film forming method of the present invention includes, for example, the following (1a) to (3a); (1a) a step of arranging a pair of substrates facing each other with a predetermined gap; and (2a) facing each other in a pair of opposite substrates. a step of applying the liquid crystal alignment agent of the present invention using a capillary phenomenon, and (3a) a step of heating the substrate after the coating.

In this method, before forming a liquid crystal alignment film on a substrate, first, two substrates are arranged to face each other with a gap (cell gap) so that the transparent conductive film of the substrate faces each other (step (1a)). Regarding the substrate used, the application can be applied Description of step (1). Then, for example, the sealant exemplified in the above step (3) is applied to the outer edge portions of the two substrates, and the two substrates are bonded together. At this time, a plurality of injection ports for injecting the liquid crystal alignment agent and the liquid crystal are provided in advance. The position of the injection port is not particularly limited, and it is preferable that a plurality of injection ports are provided at positions facing each other on the surface of each substrate.

Then, the liquid crystal alignment agent of the present invention is applied by a capillary phenomenon on the surface of the pair of substrates facing each other having the transparent conductive film (step (2a)). The method of coating the liquid crystal alignment agent on the surface of the substrate by capillary phenomenon preferably uses the following method: (i) immersing a part of the plurality of injection ports in the liquid crystal alignment agent, thereby injecting the liquid crystal alignment agent from the injection port by capillary action And a method of filling a liquid crystal alignment agent in a cell gap; (ii) injecting a liquid crystal alignment agent from a part or all of the plurality of injection ports by inkjet coating, filling the cell gap by capillary action A method of a liquid crystal alignment agent.

The liquid crystal alignment agent used in the method preferably has a solid content concentration of 0.1% by weight to 2.0% by weight. When the solid content concentration is less than 0.1% by weight, the film thickness of the coating film becomes too small to obtain a good liquid crystal alignment film. On the other hand, when the solid content concentration exceeds 2.0% by weight, the viscosity of the liquid crystal alignment agent increases. Large and poorly coated. The solid content concentration is more preferably 0.2% by weight to 1.8% by weight, still more preferably 0.3% by weight to 1.7% by weight.

After coating the liquid crystal alignment agent, it is preferred to carry out preheating (prebaking) and then carry out a calcination (postbaking) step. Thus, a coating film as a liquid crystal alignment film or a coating film which becomes a liquid crystal alignment film is formed. Regarding the temperature conditions of the prebaking and postbaking, the description of the step (1) can be applied. The prebaking time is preferably 0.25 minutes to 20 minutes. More preferably, it is 0.5 minute - 15 minutes. The post-baking time is preferably from 5 minutes to 200 minutes, more preferably from 10 minutes to 100 minutes. This method is a method in which a liquid crystal alignment film can be formed not only on a substrate for a display having a flat panel structure but also on a substrate for a curved display having a curved substrate.

After the coating film is formed, the liquid crystal is filled into the cell gap through the injection port, and then the injection hole is sealed, whereby the liquid crystal cell is manufactured. The description of the step (3) can be applied to the liquid crystal. Then, 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. Further, regarding the rubbing treatment, the description of the step (2) can be applied, and regarding the method of manufacturing the PSA type liquid crystal display element, the description of (3-2) of the step (3) can be applied.

The liquid crystal display element of the present invention can be effectively applied to various devices, for example, for watches, portable game machines, word processors, notebook computers, car navigation systems, camcorders, personal numbers. Display devices for assistants (Personal Digital Assistants, PDAs), digital cameras, mobile phones, smart phones, various monitors, LCD TVs, etc.

[Examples]

Hereinafter, the present invention will be more specifically illustrated by the examples, but the invention is not limited to the examples.

In the following examples and comparative examples, the ruthenium imidization ratio of the polyimine in the polymer solution, the solution viscosity of the polymer solution, the weight average molecular weight of the polymer, and the epoxy equivalent were measured by the following methods.

[醯Iminization rate of polyimine]

The solution of polyimine is put into pure water, and the obtained precipitate is sufficiently dried under reduced pressure at room temperature, and then dissolved in deuterated dimethyl hydrazine, and tetramethyl decane is used as a standard substance at room temperature. ¹ H-NMR (Nuclear Magnetic Resonance, NMR) was measured. From the obtained ¹ H-NMR spectrum, the oxime imidization ratio [%] was determined from the following formula (x).

醯imination rate [%]=(1-A ¹ /A ² ×α)×100...(x)

In the mathematical formula (x), A ¹ is the peak area of the proton derived from the NH group appearing near the chemical shift of 10 ppm, A ² is the peak area derived from other protons, and α is the precursor of the polymer (polyproline) The ratio of the number of other protons relative to one proton of the NH group.

[Solid viscosity of polymer solution]

Solution viscosity of polymer solution [mPa. s] is a solution prepared by using a predetermined solvent to have a polymer concentration of 10% by weight, which is measured at 25 ° C using an E-type rotational viscometer.

[weight average molecular weight of polymer]

The weight average molecular weight is a value in terms of polystyrene measured by gel permeation chromatography under the following conditions.

Pipe column: manufactured by Tosoh (stock), TSKgelGRCXLII

Solvent: tetrahydrofuran

Temperature: 40 ° C

Pressure: 68kgf/cm ²

[epoxy equivalent]

The epoxy equivalent is measured in accordance with the hydrochloric acid-methyl ethyl ketone method described in Japanese Industrial Standards (JIS) C 2105.

<Synthesis of Polymer (A)>

[Synthesis Example 1: Synthesis of Polyimine (PI-1)]

22.4 g (0.1 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride (TCA) as tetracarboxylic dianhydride, and 3,5-diaminobenzoic acid (35 DAB) as a diamine 12.2 g (0.08 mol) and cholestyloxy-2,4-diaminobenzene (HCODA) 9.80 g (0.02 mol) dissolved in N-methyl-2-pyrrolidone (NMP) 178 g at 60 The reaction was carried out for 6 hours at ° C to obtain a solution containing 20% by weight of poly-proline. The obtained polyaminic acid solution was divided into small amounts, and NMP was added to prepare a solution having a polyglycine concentration of 10% by weight and the measured solution viscosity was 88 mPa. s.

Then, NMP was added to the obtained polyamic acid solution to prepare a solution having a polyglycine concentration of 7 wt%, and 11.9 g of pyridine and 15.3 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 system is subjected to solvent replacement using a new NMP (by this operation, the pyridine and acetic anhydride used in the dehydration ring-closure reaction are removed to the outside of the system. The same applies hereinafter), thereby obtaining a ruthenium amide ratio. It is about 60% of a solution containing 26% by weight of polyimine (PI-1). The obtained polyimine solution was divided into small amounts, and NMP was added to prepare a solution having a polyamidene concentration of 10% by weight and the measured solution viscosity was 45 mPa. s.

[Synthesis Example 2: Synthesis of Polyimine (PI-2)]

22.5 g (0.1 mol) of TCA as tetracarboxylic dianhydride, and 10.7 g (0.07 mol) of 35DAB as diamine, 7.35 g (0.015 mol) of HCODA, and the formula (D-1-5) The compound (LDA) represented by 6.94 g (0.015 mol) was dissolved in 190 g of NMP, and reacted at 60 ° C for 6 hours to obtain a solution containing 20% by weight of polylysine. The obtained polyaminic acid solution was divided into small amounts, and NMP was added to prepare a solution having a polyglycine concentration of 10% by weight and the measured solution viscosity was 80 mPa. s.

Then, NMP was added to the obtained polyamic acid solution to prepare a solution having a polyamine concentration of 7 wt%, and 15.7 g of pyridine and 20.3 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 system was subjected to solvent replacement using a new NMP, whereby a solution containing 26% by weight of polyimine (PI-2) having a ruthenium iodide ratio of about 80% was obtained. The obtained polyimine solution was divided into small amounts, and NMP was added to prepare a solution having a polyimine concentration of 10% by weight and the measured solution viscosity was 40 mPa. s.

[Synthesis Example 3: Synthesis of Polyimine (PI-3)]

2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride (BODA) as tetracarboxylic dianhydride 24.9 g (0.1 mol), and as The diamine's 35DAB 10.7g (0.07 mol) and 3,5-diaminobenzoic acid cholesteryl ester (HCDA) 15.6 g (0.03 mol) were dissolved in 200 g of NMP, and reacted at 60 ° C for 6 hours. A solution containing 20% by weight of polylysine was obtained. The obtained polyaminic acid solution was divided into small amounts, and NMP was added to prepare a solution having a polyglycine concentration of 10% by weight and measured. The solution viscosity is 85mPa. s.

Then, NMP was added to the obtained polyamic acid solution to prepare a solution having a polyglycine concentration of 7 wt%, and 11.9 g of pyridine and 15.3 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 system was subjected to solvent replacement using a new NMP, whereby a solution containing 26% by weight of polyimine (PI-3) having a ruthenium iodide ratio of about 60% was obtained. The obtained polyimine solution was divided into small amounts, and NMP was added to prepare a solution having a polyimine concentration of 10% by weight and the measured solution viscosity was 43 mPa. s.

[Synthesis Example 4: Synthesis of Polyimine (PI-4)]

22.4 g (0.1 mol) of TCA as tetracarboxylic dianhydride, and 7.57 g (0.07 mol) of 4,4'-diaminodiphenylmethane as p-phenylenediamine (PDA) as diamine ( DDM) 4.0 g (0.02 mol) and HCDA 5.2 g (0.01 mol) were dissolved in 150 g of NMP, and reacted at 60 ° C for 4 hours to obtain a solution containing 10% by weight of poly-proline. The obtained polyaminic acid solution was divided into small amounts, and NMP was added to prepare a solution having a polyglycine concentration of 10% by weight and the measured solution viscosity was 90 mPa. s.

Then, 188 g of NMP was added to the obtained polyamic acid solution, and 11.9 g of pyridine and 15.3 g of acetic anhydride were added, and the dehydration ring-closure reaction was carried out at 110 ° C for 4 hours. After the dehydration ring closure reaction, the solvent in the system was subjected to solvent replacement using a new NMP to obtain a solution containing 26% by weight of polyimine (PI-4) having a ruthenium iodide ratio of about 70%. The obtained polyimine solution was divided into small amounts and the measured solution viscosity was 50 mPa. s.

[Synthesis Example 5: Synthesis of polyorganosiloxane (APS-1)]

In a reaction vessel equipped with a stirrer, a thermometer, a dropping funnel, and a reflux condenser, 100.0 g of 2-(3,4-epoxycyclohexyl)ethyltrimethoxydecane (ECETS) and 500 g of methyl isobutyl ketone were added. And 10.0 g of triethylamine, and mixed at room temperature. Then, 100 g of deionized water was added dropwise from the dropping funnel over 30 minutes, and the reaction was carried out at 80 ° C for 6 hours while stirring under reflux. After completion of the reaction, the organic layer was taken out and washed with a 0.2% by weight aqueous solution of ammonium nitrate until the water after washing became neutral, and then the solvent and water were distilled off under reduced pressure to obtain a viscous transparent liquid. A reactive polyorganosiloxane (EPS-1) is obtained in the form. ¹ H-NMR analysis of the reactive polyorganooxane showed that a theoretically strong epoxy group-based peak was obtained in the vicinity of the chemical shift (δ) = 3.2 ppm, and it was confirmed that no epoxy group was caused in the reaction. side effects. The obtained reactive polyorganosiloxane had a weight average molecular weight Mw of 3,500 and an epoxy equivalent of 180 g/mol.

Then, 10.0 g of a reactive polyorganosiloxane (EPS-1), 30.28 g of methyl isobutyl ketone as a solvent, and 4-dodecyloxybenzoic acid as a reactive compound were placed in a 200 mL three-necked flask. 3.98 g and 0.10 g of UCAT 18X (trade name, manufactured by San-Apro Co., Ltd.) as a catalyst were reacted at 100 ° C for 48 hours under stirring. After completion of the reaction, ethyl acetate was added to the reaction mixture, and the obtained solution was washed with water three times. After drying the organic layer with magnesium sulfate, the solvent was distilled off to obtain a liquid crystal-aligned polyorganosiloxane (APS-1). ) 9.0g. The obtained polymer had a weight average molecular weight Mw of 9,900.

<Example 1>

[Preparation of Liquid Crystal Aligning Agent]

In a solution containing polyimine (PI-1) as the polymer (A), a polyorganosiloxane (APS-1) as a polymer (A) and γ-butyrolactone as a solvent (BL) are added. ), N-ethylpyrrolidone (NEP), butyl cellosolve (BC) and ethylene glycol (EG), the polymer composition is (PI-1): (APS-1) = 95:5 (weight ratio) The solvent composition was BL: NEP: BC: EG = 10: 40: 30: 20 (weight ratio), and a solution having a solid concentration of 3.5% by weight. This solution was filtered using a filter having a pore size of 1 μm, thereby preparing a liquid crystal alignment agent (S-1).

[Evaluation of film thickness at the end of coating film]

The liquid crystal alignment agent (S-1) prepared above was applied onto a tantalum wafer using an inkjet coating apparatus (manufactured by Shibaura Mechatronics Co., Ltd.). The coating conditions were set to 64 nozzles, 0.2 g/head/sec, and 2 round-trip coatings (4 coatings). Then, the solvent was removed by heating (prebaking) on a hot plate at 80 ° C for 1 minute to form a coating film having an average film thickness of 80 nm. The coating film formed on the ruthenium wafer was visually observed, and the width of the portion (the portion where the film thickness was poor) whose film thickness was thinner than the center portion and whose color tone was changed at the end portion of the coating film was measured, and the width was determined according to the width. Film thickness evaluation was performed. In the evaluation, the case where the width of the portion where the color tone changes in the end portion of the coating film was 3 mm or less was evaluated as "particularly good", and the case where the width was longer than 3 mm and 4 mm or less was evaluated as "good", and the width was longer than 4 mm. The situation was evaluated as "bad". The results are shown in Table 1 below.

In Table 1, the abbreviations of the solvents are as follows.

[compound (b)]

EG: ethylene glycol

PG: propylene glycol (1,2-propanediol)

BG: β-butanediol (1,3-butanediol)

HG: hexanediol (2-methylpentane-2,4-diol)

DEG: diethylene glycol (3-oxapentane-1,5-diol)

DPG: dipropylene glycol (4-oxaheptane-2,6-diol)

[1st solvent (a)]

BL: γ-butyrolactone

NEP: N-ethyl-2-pyrrolidone

NMP: N-methyl-2-pyrrolidone

[other solvents (c)]

BC: butyl cellosolve

DAA: Diacetone alcohol

PGDAc: propylene glycol diacetate

<Example 2 to Example 4>

A liquid crystal alignment agent (S-2) to a liquid crystal alignment agent (S-4) were prepared in the same manner as in Example 1 except that the type and amount of the solvent to be used were changed as in Table 1. Further, using the prepared liquid crystal alignment agent, a coating film was formed on the substrate in the same manner as in Example 1, and the film thickness of the coating film was evaluated. The results of these evaluations are shown in Table 1.

<Example 5 to Example 10, Comparative Example 1>

The type of the polymer (A) to be used was changed to one type as in the above-mentioned Table 1, and the liquid crystal alignment agent was prepared in the same manner as in Example 1 except that the type and amount of the solvent to be used were changed as shown in Table 1. (S-5) ~ Liquid crystal alignment agent (S-10), liquid crystal alignment agent (SR-1). Further, using the prepared liquid crystal alignment agent, a coating film was formed on the substrate in the same manner as in Example 1, and the film thickness of the coating film was evaluated. The results of these evaluations are shown in Table 1.

As shown in Table 1, in Examples 1 to 10 containing the compound (b), the width of the region where the film thickness at the end of the coating film was poor was 4 mm or less, and the film thickness was good. In this case, it is suggested that the liquid crystal alignment agent containing the compound (b) can effectively use a wide range of the coating film region as the display region, and the narrow edge of the liquid crystal panel can be achieved. Further, it is presumed that by adding the compound (b) to the liquid crystal alignment agent, the viscosity of the liquid crystal alignment agent can be appropriately increased, whereby the effect can be obtained. Further, in the examples, in the case of the liquid crystal alignment agent (Examples 1 to 9) containing the polymer (A) having a carboxyl group in the side chain, the width of the region where the film thickness at the end portion of the coating film is poor is 3mm or less, especially good. On the other hand, in the case of Comparative Example 1 containing no compound (b), the width of the portion where the film thickness at the end portion of the coating film was thinned was as large as 4.2 mm.

<Example 11>

[Preparation of Liquid Crystal Aligning Agent]

In a solution containing polyimine (PI-1) as the polymer (A), a polyorganosiloxane (APS-1) as a polymer (A) and γ-butyrolactone as a solvent (BL) are added. ), N-ethylpyrrolidone (NEP), butyl cellosolve (BC) and ethylene glycol (EG), the polymer composition is (PI-1): (APS-1) = 95:5 (weight ratio) The solvent composition was BL: NEP: BC: EG = 10: 40: 30: 20 (weight ratio), and the solid content concentration was 1.0% by weight. This solution was filtered using a filter having a pore size of 1 μm, thereby preparing a liquid crystal alignment agent (S-11).

[Manufacture of liquid crystal cell]

An epoxy resin adhesive to which an alumina ball having a diameter of 5.5 μm was added was coated on the outer edge of a pair of ITO-attached substrates. At this time, the adhesive is not applied to a part of the two sides facing each other in the outer edge of the substrate, thereby ensuring liquid crystal matching on the upper and lower sides of the substrate. The injection port of the agent and the liquid crystal. Then, the ITO faces are overlapped and crimped so as to be hardened. Then, the prepared liquid crystal alignment agent (S-11) was placed in a petri dish in an appropriate amount, and one of the injection ports of the pair of ITO substrates prepared above was immersed in a petri dish. After the liquid crystal alignment agent (S-11) was filled between the ITO substrates by capillary action, it was heated (prebaked) on a hot plate at 80 ° C for 10 minutes to remove the solvent, and then heated on a hot plate at 210 ° C (post-baking) Bake) for 30 minutes to form a coating film having an average film thickness of 10 nm. Next, a nematic liquid crystal (MLC-6608 manufactured by Merck Co., Ltd.) was filled between the pair of substrates from the injection port, and then the injection port was sealed with an acrylic photocurable adhesive to produce a liquid crystal cell.

[Evaluation of liquid crystal alignment of liquid crystal cell]

With respect to the central portion of the liquid crystal cell obtained above, a liquid crystal alignment property was evaluated using a polarizing microscope in which a polarizing plate was arranged to have a cross nicol. In addition, a polarizing microscope manufactured by Olympus was used, and a 10x eyepiece and a 5x objective lens were used. The evaluation is performed based on the number of display defects called disclinations. Here, the "dislocation" means a linear white defect, which is presumed to be caused by insufficient liquid crystal alignment regulating force of the liquid crystal alignment film. Here, the case where the number of the disclination is 0 is evaluated as the orientation "good (○)", and the case where the number of the disclination is 1 to 3 is evaluated as the orientation "Yes (△)". The case where the number of disclinations was four or more was evaluated as an orientation "not (x)". As a result, in the case of the liquid crystal alignment agent (S-11) of Example 11, the number of disclinations was zero, and the liquid crystal alignment property was good.

<Example 12 to Example 14>

The liquid crystal alignment agent (S-12) to liquid crystal alignment agent (S-14) was prepared in the same manner as in Example 11 except that the type and amount of the solvent to be used and the solid content concentration of the liquid crystal alignment agent were changed as shown in Table 2 below. ). Further, a liquid crystal cell was produced in the same manner as in Example 11 except that the prepared liquid crystal alignment agent was used, and the alignment property of the liquid crystal cell was evaluated. The results of these evaluations are shown in Table 2 below.

<Example 15 to Example 20, Comparative Example 2>

The type of the polymer (A) to be used is changed to one type as shown in Table 2, and the type and amount of the solvent to be used are changed as shown in Table 2, and the solid of the liquid crystal alignment agent is set as in Table 2 Ingredient concentration, in addition to the above, A liquid crystal alignment agent (S-15) to a liquid crystal alignment agent (S-20) and a liquid crystal alignment agent (SR-2) were prepared in the same manner as in Example 11. Further, a liquid crystal cell was produced in the same manner as in Example 11 except that the prepared liquid crystal alignment agent was used, and the alignment property of the liquid crystal cell was evaluated. The results of these evaluations are shown in Table 2.

As shown in Table 2, in Examples 11 to 20 containing the compound (b), the number of disclinations caused by the alignment failure was zero, and the liquid crystal alignment property was good. In this case, it is suggested that a liquid crystal alignment agent containing the compound (b) can form a liquid crystal alignment film having good alignment by capillary action, and can form a liquid crystal having excellent alignment even in a complicated shape panel such as a curved surface panel. Orientation film. Further, it is presumed that by adding the compound (b) to the liquid crystal alignment agent, the viscosity of the liquid crystal alignment agent can be appropriately increased even if the solid content concentration is low, whereby the effect can be obtained. Further, in the examples, in the case of the liquid crystal alignment agent (Examples 11 to 19) containing the polymer (A) having a carboxyl group in the side chain, the number of disclinations due to the alignment failure is 0, which is particularly good. . On the other hand, in the case of Comparative Example 2 containing no compound (b), it was found that up to ten disclinations due to poor alignment were observed.

Claims (9)

A liquid crystal alignment agent comprising at least one polymer (A) selected from the group consisting of polylysine, polyphthalate, and polyamidene, and a solvent, and the solvent contains a relative The compound (b) represented by the following formula (1) in the range of 1% by weight to 60% by weight based on the total amount of the solvent, [Chemical Formula 1] HO-R ¹ -OH (1) In the formula (1), R ¹ is A divalent chain hydrocarbon group or an alicyclic hydrocarbon group having 2 to 10 carbon atoms or a divalent group having "-O-" between the carbon-carbon bonds of the chain hydrocarbon group or the alicyclic hydrocarbon group. The liquid crystal alignment agent according to claim 1, wherein the polymer (A) is at least one selected from the group consisting of tetracarboxylic dianhydride and tetracarboxylic acid ester and a diamine compound. The polymer obtained by the reaction contains a diamine (d-1) having a carboxyl group as the diamine compound. The liquid crystal alignment agent according to claim 1 or 2, wherein the compound (b) has a carbon number of 3 to 7. The liquid crystal alignment agent according to claim 1 or 2, wherein the polymer (A) is a polymer obtained by reacting a tetracarboxylic dianhydride with a diamine compound, As the tetracarboxylic dianhydride, it is selected from the group consisting of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride and 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4. At least one of the group consisting of 6:8-dianhydride and 1,2,3,4-cyclobutanetetracarboxylic dianhydride. The liquid crystal alignment agent according to claim 1 or 2, wherein the solid content concentration is from 0.1% by weight to 2.0% by weight. A method for producing a liquid crystal alignment film, comprising: a step of applying a liquid crystal alignment agent according to any one of claims 1 to 5 to a substrate by an inkjet method; The step of heating the substrate after coating is described. A method for producing a liquid crystal alignment film, comprising: a step of arranging a pair of substrates facing each other with a predetermined gap; and coating the opposite faces of the pair of substrates facing each other by capillary phenomenon The step of applying the liquid crystal alignment agent according to any one of claims 1 to 5, and the step of heating the substrate after the coating. A liquid crystal alignment film which is formed by using the liquid crystal alignment agent according to any one of claims 1 to 5. A liquid crystal display element comprising the liquid crystal alignment film according to item 8 of the patent application.