KR102225380B1 - Liquid crystal aligning agent, liquid crystal alignment film and liquid crystal display device - Google Patents

Abstract

(Problem) A liquid crystal aligning agent for obtaining a liquid crystal display element which can suppress the occurrence of ODF unevenness and has good electrical properties is provided.
(Solution means) In the liquid crystal aligning agent, a polyorganosiloxane having a heterocyclic structure (a) containing a nitrogen atom in the ring skeleton is contained.

Description

Liquid crystal aligning agent, liquid crystal aligning film, and liquid crystal display device {LIQUID CRYSTAL ALIGNING AGENT, LIQUID CRYSTAL ALIGNMENT FILM AND LIQUID CRYSTAL DISPLAY DEVICE}

This invention relates to a liquid crystal aligning agent, a liquid crystal aligning film, and a liquid crystal display element, and especially relates to a liquid crystal aligning agent etc. suitably used for manufacture of a vertical alignment type liquid crystal display element.

The liquid crystal display element is equipped with a liquid crystal aligning film which controls the alignment of liquid crystal molecules. For example, a liquid crystal display element conventionally known as a vertical alignment mode includes a liquid crystal alignment film having a function of aligning liquid crystal molecules in a vertical direction. As a material constituting this liquid crystal aligning film, polyamic acid, polyimide, polyamide, polyester, polyorganosiloxane, etc. are known, and in particular, a liquid crystal aligning film made of polyamic acid or polyimide has heat resistance, mechanical strength, and liquid crystal molecules. From the viewpoint of excellent affinity of, for example, it has been preferably used from ancient times (see, for example, Patent Document 1). In addition, in recent years, there are cases in which a liquid crystal aligning agent containing a polyorganosiloxane obtained by reacting a trifunctional or tetrafunctional hydrolyzable silane compound is used for reasons such as good light resistance and heat resistance (for example, See Patent Documents 2 to 4).

In recent years, in the manufacturing process of a liquid crystal display device, a liquid crystal drop method (one drop fill method, abbreviated as "ODF method") is a method of manufacturing a liquid crystal cell that has been adopted along with an increase in the size of a substrate. In the ODF method, a required amount of liquid crystal is dropped onto a predetermined number of places on the substrate on which the liquid crystal alignment film is formed, and the liquid crystal is bonded to the other substrate in a vacuum, and at the same time, the liquid crystal is spread over the entire surface of the substrate, and then a seal to seal the liquid crystal. It is a method of filling the entire surface of the panel with liquid crystal by UV curing the agent. This method is a technology capable of significantly shortening the process time of the liquid crystal filling process compared to the conventional vacuum injection method. In particular, this method is often used in the manufacture of vertically aligned liquid crystal display elements used in large-sized liquid crystal display elements such as televisions.

Japanese Unexamined Patent Publication No. 2010-97188 Japanese Laid-Open Patent Publication No. Hei 9-281502 Japanese Patent Publication No. 4458305 Japanese Patent Publication No. 4458306

While the method of manufacturing a liquid crystal display device by the ODF method has the above advantages, display unevenness called "ODF unevenness" is liable to occur, which may affect display quality. Due to the recent increase in demand for improvement in display quality, even finer irregularities may be judged as poor quality, and a technology capable of sufficiently suppressing the occurrence of ODF irregularities is required.

Further, in recent years, in order to increase the high-speed response of a liquid crystal panel, there is a tendency to use a liquid crystal having a higher polarity. It is known that such an improvement in polarity increases the content of ionic impurities at the same time, leading to a decrease in residual image characteristics and reliability of a liquid crystal display device. In order to further improve the display quality and reliability of a liquid crystal display element, even when such a high-polarity liquid crystal is used, a liquid crystal display element exhibiting a higher level of electrical characteristics, that is, a high voltage retention rate, is required.

The present invention has been made in view of the above circumstances, and one object thereof is to provide a liquid crystal aligning agent for obtaining a liquid crystal display element that can suppress the occurrence of ODF non-uniformity and has good electrical properties.

The inventors of the present invention found that the above problems could be solved by incorporating a polyorganosiloxane having a specific structure in a liquid crystal aligning agent as a result of intensive examination in order to solve the above problems, and the present invention was completed. Specifically, the following liquid crystal aligning agent, a liquid crystal aligning film, and a liquid crystal display element are provided by this invention.

In one aspect, the present invention provides a liquid crystal aligning agent containing a polyorganosiloxane having a heterocyclic structure (a) containing a nitrogen atom in a ring skeleton.

In another aspect, the present invention provides a liquid crystal aligning layer formed using the liquid crystal aligning agent. In addition, a liquid crystal display device including the liquid crystal alignment layer is provided.

According to the liquid crystal aligning agent of the present invention, a liquid crystal display element with little ODF unevenness can be obtained when the ODF system is employed in the manufacturing process of a liquid crystal display element. Moreover, by forming a liquid crystal aligning film using the liquid crystal aligning agent of this invention, a liquid crystal display element excellent in electrical characteristics can be obtained. Therefore, the liquid crystal aligning agent of this invention can be applied suitably to the mass production process of a current liquid crystal display element.

The liquid crystal aligning agent of this invention contains a polyorganosiloxane which has a heterocyclic structure (a) containing a nitrogen atom in a ring skeleton. Hereinafter, each component contained in the liquid crystal aligning agent of the present invention and other components optionally blended as necessary will be described.

≪Heterocyclic structure (a)≫

The heterocyclic structure (a) should just have a cyclic structure containing one or more nitrogen atoms in the ring skeleton. The number of rings constituting the heterocyclic structure (a) is not particularly limited, and may be a monocyclic ring or a condensed ring. Further, in the ring skeleton, only a nitrogen atom may be included as a hetero atom, and a nitrogen atom and a hetero atom other than the nitrogen atom (oxygen atom, sulfur atom, etc.) may be included. The number of nitrogen atoms contained in the ring skeleton of the heterocyclic structure (a) may be one or two or more. When the heterocyclic structure (a) is a condensed ring and has a plurality of nitrogen atoms in the ring skeleton, the plurality of nitrogen atoms may be present in the same ring or may be present in different rings.

Specific examples of the heterocyclic structure (a) include, for example, non-aromatic heterocycles such as pyrrolidine, piperidine, piperazine, hexamethyleneimine, imidazoline, and morpholine; Pyrrole, imidazole, pyrazole, triazole, pyridine, pyrimidine, pyridazine, pyrazine, indole, benzoimidazole, purine, quinoline, isoquinoline, naphthyridine, quinoxaline, phthalazine, triazine, azepine , Diazepine, acridine, phenadine, phenanthroline, oxazole, thiazole, carbazole, thiadiazole, benzothiazole, phenothiadine, oxadiazole, and other aromatic heterocycles; And a structure obtained by removing one or more hydrogen atoms from.

In the heterocyclic structure (a), a substituent may be introduced into an atom constituting the exemplified ring skeleton. Examples of the substituent include halogen atoms such as a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom; A chain or branched alkyl group having 1 to 20 carbon atoms such as a methyl group, an ethyl group, and a propyl group; Alkoxy groups having 1 to 20 carbon atoms such as a methoxy group, an ethoxy group, and a propoxy group; A cycloalkyl group having 6 to 20 carbon atoms such as a cyclopentyl group and a cyclohexyl group; Aryl groups having 6 to 20 carbon atoms such as a phenyl group and a tolyl group; And the like.

The heterocyclic structure (a) is preferably an aromatic heterocyclic structure among the above, and preferred specific examples thereof include, for example, pyrrole, imidazole, pyrazole, triazole, pyridine, pyrimidine, pyridazine, pyrazine, tri And a structure obtained by removing one or more hydrogen atoms from an aromatic heterocycle such as azine. Among these, it is preferable to have a plurality of nitrogen atoms in the ring skeleton from the point that it is possible to increase the suppression effect of ODF unevenness by promoting thermal curing at the time of post-baking and from the point that the voltage retention rate can be increased. It is more preferable to have two or three. In particular, it is preferable that the heterocyclic structure (a) is an imidazole structure.

≪Specific polyorganosiloxane (A)≫

The polyorganosiloxane (hereinafter, also referred to as "specific polyorganosiloxane (A)") having the heterocyclic structure (a) can be synthesized by appropriately combining normal methods of organic chemistry. As a specific example, for example,

(1) An alkoxysilane compound having the heterocyclic structure (a) (hereinafter, also referred to as ``specific silane compound (ms-1)''), or a mixture of a specific silane compound (ms-1) and other alkoxysilane compounds A method of hydrolyzing and condensing;

(2) After hydrolyzing and condensing an alkoxysilane compound having an epoxy group (hereinafter also referred to as ``a silane compound containing an epoxy group'') or a mixture of an epoxy group-containing silane compound and other silane compounds to obtain an epoxy group-containing polyorganosiloxane , A method of reacting the epoxy group-containing polyorganosiloxane with a carboxylic acid having the heterocyclic structure (a) (hereinafter, also referred to as "specific carboxylic acid (mc-1)");

(3) a method of reacting the specific silane compound (ms-1) or a mixture of the specific silane compound (ms-1) and other silane compounds in the presence of dicarboxylic acid and alcohol;

(4) After reacting the epoxy group-containing silane compound or a mixture of the epoxy group-containing silane compound and other silane compounds in the presence of dicarboxylic acid and alcohol to obtain an epoxy group-containing polyorganosiloxane, this epoxy group-containing polyorganosiloxane And a method of reacting the specific carboxylic acid (mc-1); And the like.

<Method (1)>

Examples of the specific silane compound (ms-1) include 2-(2-pyridyl)ethyltrimethoxysilane, 2-(2-pyridyl)ethyltriethoxysilane, and 2-(4-pyridyl) Ethyltrimethoxysilane, 2-(4-pyridyl)ethyltriethoxysilane, 2-(N-pyrrolyl)ethyltrimethoxysilane, 2-(2-pyridyl)ethylthiopropyltrimethoxysilane, Silane compounds having a heterocycle containing one nitrogen atom such as 2-(4-pyridyl)ethylthiopropyltrimethoxysilane;

3-(2-imidazolin-1-yl)propyltriethoxysilane, N-(1H-imidazol-2-yl)methylaminopropyltrimethoxysilane, N-(4-methyl-1H-imidazole -5-yl)methylaminopropyltrimethoxysilane, N-(4-methyl-2-phenyl-1H-imidazol-5-yl)methylaminopropyltrimethoxysilane, N-(2-methyl-1H- Imidazol-1-yl)methylaminopropyltrimethoxysilane, N-(2-phenyl-1H-imidazol-1-yl)methylaminopropyltrimethoxysilane, 3-(1H-imidazol-1-yl) )Propan-2-ol-1-oxypropyltrimethoxysilane, 3-(1H-imidazol-1-yl)propyloxypropyltrimethoxysilane, 3-(2-pyridyl)ureidopropyltriethoxy Silane compounds having a heterocycle containing two or more nitrogen atoms such as silane; And the like. Among these, a silane compound having two or more nitrogen atoms in the ring skeleton is preferable, and a silane compound having an imidazole structure is more preferable, from the viewpoint of having a high effect of suppressing ODF unevenness and a high voltage retention rate. In addition, the specific silane compound (ms-1) can be used alone or in combination of two or more.

In the synthesis of a specific polyorganosiloxane (A) by method (1), a specific silane compound (ms-1) may be used alone, but other silane compounds other than the specific silane compound (ms-1) may be used. You may use it together. Examples of such other silane compounds include tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, and trimethoxysilylpropylsuccinic acid. Alkoxysilanes containing hydrocarbon side chains such as anhydride, dimethyldimethoxysilane, and dimethyldiethoxysilane;

3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, mercaptomethyltrimethoxysilane, mercaptomethyltriethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureido Propyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-(3-cyclohexylamino)propyltrimethoxysilane, N-2-(aminoethyl)-3- Alkoxysilanes containing nitrogen and sulfur atoms such as aminopropyltrimethoxysilane;

3-(meth)acryloyloxypropyltrimethoxysilane, 3-(meth)acryloyloxypropyltriethoxysilane, 6-(meth)acryloyloxyhexyltrimethoxysilane, 8-(meth) Acryloyloxyoctyltrimethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 3-(meth)acryloxypropylmethyldiethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, p- Alkoxysilanes containing unsaturated hydrocarbons such as styryl trimethoxysilane;

3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxypropylmethyldimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 3- Glycidyloxypropyldimethylmethoxysilane, 3-glycidyloxypropyldimethylethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl) Epoxy group-containing alkoxysilanes such as ethyl triethoxysilane; And the like. Among these, at least any one of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidyloxypropyltrimethoxysilane, and 8-glycidyloxyoctyltrimethoxysilane is particularly preferred. Can be used. In addition, the other silane compounds described above may be used singly or in combination of two or more. In this specification, "(meth)acryloyl" means including acryloyl and methacryloyl.

In the synthesis of the specific polyorganosiloxane (A) by the method (1), the ratio of the specific silane compound (ms-1) to be used is from the viewpoint of sufficiently obtaining the effect of suppressing the occurrence of ODF unevenness and from the viewpoint of electrical properties, It is preferable to set it as 0.5 mol% or more with respect to the total amount of the silane compound used for synthesis, it is more preferable to set it as 1 to 50 mol%, and it is still more preferable to set it as 2 to 30 mol%.

[Hydrolysis/condensation reaction of silane compound]

The hydrolysis/condensation reaction of the silane compound in the method (1) can be carried out by reacting one or two or more silane compounds with water, preferably in the presence of an appropriate catalyst and an organic solvent, as described above.

Examples of the catalyst include acids, alkali metal compounds, organic bases, titanium compounds, and zirconium compounds. As specific examples of these catalysts, examples of the acid include hydrochloric acid, sulfuric acid, nitric acid, formic acid, oxalic acid, acetic acid, trifluoroacetic acid, trifluoromethanesulfonic acid, phosphoric acid, acidic ion exchange resin, various Lewis acids, and the like;

Examples of the alkali metal compound include sodium hydroxide, potassium hydroxide, sodium methoxide, potassium methoxide, sodium ethoxide, potassium ethoxide, and the like;

As the organic base, for example, primary to secondary organic amines such as ethylamine, diethylamine, piperazine, piperidine, pyrrolidine, and pyrrole: triethylamine, tri-n-propylamine, tri-n- Tertiary organic amines such as butylamine, pyridine, 4-dimethylaminopyridine, and diazabicyclodecene: quaternary organic amines such as tetramethylammonium hydroxide; Each can be mentioned. As the organic base, among these, a tertiary organic amine or a quaternary organic amine is preferred.

As the catalyst, an alkali metal compound or an organic base is preferable among these catalysts in terms of being able to suppress side reactions such as ring opening of an epoxy group, speeding up the rate of hydrolysis and condensation, and excellent storage stability. Organic bases are preferred.

The amount of organic base used is different depending on the reaction conditions such as the type of organic base and temperature, and should be set appropriately, but is preferably 0.01 to 3 times mole, more preferably 0.05 to 1 times mole relative to the total silane compound. .

Examples of the organic solvent used in the hydrolysis/condensation reaction include hydrocarbons, ketones, esters, ethers, and alcohols. As specific examples of them, examples of hydrocarbons include toluene and xylene; Examples of ketones include methyl ethyl ketone, methyl isobutyl ketone, methyl n-amyl ketone, diethyl ketone, cyclohexanone, cyclopentanone, and the like; Examples of the ester include ethyl acetate, n-butyl acetate, i-amyl acetate, propylene glycol monomethyl ether acetate, 3-methoxybutyl acetate, ethyl lactate, and the like; Examples of the ether include ethylene glycol dimethyl ether, ethylene glycol diethyl ether, tetrahydrofuran, dioxane, and the like; Examples of alcohols include 1-hexanol, 4-methyl-2-pentanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-n-butyl ether, Propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, and the like; Each can be mentioned. Among these, it is preferable to use a water-insoluble organic solvent. Moreover, these organic solvents can be used individually by 1 type or in mixture of 2 or more types.

The proportion of the organic solvent used in the hydrolytic condensation reaction is preferably 10 to 10,000 parts by weight, more preferably 50 to 1,000 parts by weight, based on 100 parts by weight of all the silane compounds used in the reaction.

The hydrolysis/condensation reaction is preferably carried out by dissolving the above-described silane compound in an organic solvent, mixing this solution with an organic base and water, and heating it with, for example, an oil bath. During the hydrolysis/condensation reaction, the heating temperature is preferably set to 130°C or lower, and more preferably set to 40 to 100°C. The heating time is preferably 0.5 to 12 hours, more preferably 1 to 8 hours. During heating, the liquid mixture may be stirred or placed under reflux. After completion of the reaction, it is preferable to wash the organic solvent layer separated from the reaction solution with water. In this washing, washing with water containing a small amount of salt (for example, an aqueous solution of about 0.2% by weight of ammonium nitrate, etc.) is preferable from the viewpoint of facilitating the washing operation. Washing is performed until the aqueous layer after washing becomes neutral, and then the organic solvent layer is dried with a drying agent such as anhydrous calcium sulfate or molecular sieve, if necessary, and then the target polyorganosiloxane is removed by removing the solvent. Can be obtained.

In addition to the specific polyorganosiloxane (A) obtained by the above reaction, a group (hereinafter, also referred to as “alignment group”) that exhibits liquid crystal alignment ability may be introduced. Introduction of the orientation group is, for example, by polymerization of a monomer containing an epoxy group-containing silane compound to synthesize a specific polyorganosiloxane (A) having an epoxy group, and the obtained epoxy group-containing specific polyorganosiloxane (A) , It can be carried out by reacting a carboxylic acid having an orientation group (hereinafter, also referred to as "orientation group-containing carboxylic acid").

Specific examples of such an oriented group-containing carboxylic acid include, for example, long-chain fatty acids such as capronic acid, n-octanoic acid, n-decanoic acid, n-dodecanoic acid, n-hexadecanoic acid, and stearic acid; Benzoic acid having a long-chain alkyl group such as 4-n-hexylbenzoic acid, 4-n-octylbenzoic acid, 4-n-decylbenzoic acid, 4-n-dodecylbenzoic acid, 4-n-hexadecylbenzoic acid, and 4-stearylbenzoic acid; 4-n-hexyloxybenzoic acid, 4-n-octyloxybenzoic acid, 4-n-decyloxybenzoic acid, 4-n-dodecyloxybenzoic acid, 4-n-hexadecyloxybenzoic acid, 4-stearyloxybenzoic acid, etc. Benzoic acid having a long chain alkoxy group; Cholestanyloxybenzoic acid, cholesteryloxybenzoic acid, lanostanyloxybenzoic acid, cholestanyloxycarbonylbenzoic acid, cholesteryloxycarbonylbenzoic acid, ranostanyloxycarbonylbenzoic acid, succinic acid-5ξ-cholestane-3 Benzoic acid having a steroid skeleton such as -yl, succinic acid-5ξ-cholesten-3-yl, and succinic acid-5ξ-lanostan-3-yl; 4-(4-pentyl-cyclohexyl)benzoic acid, 4-(4-hexyl-cyclohexyl)benzoic acid, 4-(4-heptyl-cyclohexyl)benzoic acid, 4'-pentyl-bicyclohexyl-4-carboxylic acid, 4'-hexyl-bicyclohexyl-4-carboxylic acid, 4'-heptyl-bicyclohexyl-4-carboxylic acid, 4'-pentyl-biphenyl-4-carboxylic acid, 4'-hexyl-biphenyl-4 -Carboxylic acid, 4'-heptyl-biphenyl-4-carboxylic acid, 4-(4-pentyl-bicyclohexyl-4-yl)benzoic acid, 4-(4-hexyl-bicyclohexyl-4-yl)benzoic acid , 4-(4-heptyl-bicyclohexyl-4-yl)benzoic acid, 6-(4'-cyanobiphenyl-4-yloxy)hexanoic acid, 4-(4-pentylcyclohexyl)oxidodecanoic acid, Benzoic acid having a polycyclic structure such as 11-((4'-pentylbicyclohexyl-4-yl)oxy)dodecanoic acid and 11-(4-(4-pentylcyclohexyl)phenyloxy)dodecanoic acid; Carboxylic acids having a fluoroalkyl group such as 6,6,6-trifluorohexanoic acid and 4-(4,4,4-trifluorobutyl)benzoic acid; And the like. In addition, the oriented group-containing carboxylic acid can be used alone or in combination of two or more.

In the case of the reaction between the specific polyorganosiloxane (A) and the carboxylic acid, the oriented group-containing carboxylic acid may be used alone, but other carboxylic acids other than the carboxylic acid may be used in combination. Specific examples of such other carboxylic acids include formic acid, acetic acid, propionic acid, benzoic acid, methylbenzoic acid, acrylic acid, methacrylic acid, 2-acryloyloxyethyl-2-hydroxyethyl-phthalic acid, 2-(meth) And acryloyloxyethylhexahydrophthalic acid. In addition, details of the reaction between the specific polyorganosiloxane (A) having an epoxy group and the oriented group-containing carboxylic acid will be described together in the following method (2).

<Method (2)>

Examples of the epoxy group-containing silane compound used in the synthesis of the epoxy group-containing polyorganosiloxane in the method (2) include compounds exemplified as epoxy group-containing alkoxysilanes in the other silane compounds of the method (1). I can.

When synthesizing the epoxy group-containing polyorganosiloxane, an epoxy group-containing silane compound may be used alone, or other silane compounds other than the epoxy group-containing silane compound may be used in combination. Examples of the other silane compounds include compounds exemplified as other silane compounds in the method (1) and the specific silane compound (ms-1).

In the synthesis of the epoxy group-containing polyorganosiloxane, the ratio of the epoxy group-containing silane compound to be used is from the viewpoint of introducing a sufficient amount of the heterocyclic structure (a) and an aligning group into the side chain of the polymer. It is preferable to set it as 10 mol% or more with respect to the total amount, it is more preferable to set it as 20-100 mol%, and it is still more preferable to set it as 40-100 mol%.

When using the specific silane compound (ms-1) as the other silane compound, the ratio may be appropriately set according to the amount of the specific carboxylic acid (mc-1), but the total amount of the silane compound used for synthesis Relatively, it is preferably 0.3 mol% or more, more preferably 0.5 to 40 mol%, and still more preferably 1 to 30 mol%.

In addition, the description of the above method (1) can be applied to details of the catalyst, reaction solvent, and reaction conditions used in the hydrolysis/condensation reaction of the silane compound in the method (2).

As the specific carboxylic acid (mc-1) to be reacted with the epoxy group-containing polyorganosiloxane, for example,

Picolinic acid, nicotinic acid, isonicotinic acid, 5-butylpyridine-2-carboxylic acid, 3-methylpyridine-2-carboxylic acid, 6-methoxypyridine-2-carboxylic acid, 5-fluoro-2-pyridinecarboxylic acid , 6-fluoro-2-pyridinecarboxylic acid, 3-pyridin-2-ylbenzoic acid, 3-pyridin-3-ylbenzoic acid, 3-pyridin-4-ylbenzoic acid, 4-pyridin-2-ylbenzoic acid, 4- Carboxylic acids having a heterocycle containing one nitrogen atom, such as pyridin-3-ylbenzoic acid, 4-pyridin-4-ylbenzoic acid, and 1-(pyridin-3-yl)cyclopropanecarboxylic acid;

4-Imidazolecarboxylic acid, 1-methyl-1H-imidazol-2-carboxylic acid, 4-(1H-imidazol-1-yl)benzoic acid, 4-[(1H-imidazol-1-yl)methyl] Benzoic acid, 4-[2-(1H-imidazol-1-yl)ethoxy]benzoic acid, 4-(4,5-diphenyl-1H-imidazol-2-yl)benzoic acid, 4-(4,5- Diphenyl-1H-imidazol-2-yl)benzoic acid, 3-(1H-imidazol-1-ylmethyl)-4-methoxybenzoic acid, 5-benzimidazolecarboxylic acid, 2-benzyl-1H-benzimi Dazole-6-carboxylic acid, 2-benzyl-1-methyl-1H-benzimidazole-6-carboxylic acid, 1-[4-(benzyloxy)phenyl]-1H-benzimidazole-5-carboxylic acid, 1 -[4-(benzyloxy)phenyl]-2-methyl-1H-benzimidazole-5-carboxylic acid, 1-cyclohexyl-2-methyl-1H-benzoimidazole-5-carboxylic acid, 1-(3 ,4-difluorophenyl)-1H-benzimidazole-5-carboxylic acid, 1,2-dimethyl-1H-benzoimidazole-5-carboxylic acid, 2-ethyl-1H-benzimidazole-6-carbon Contains two or more nitrogen atoms, such as acid, 6-(1H-imidazol-1-yl)nicotinic acid, and 1-(3-methoxyphenyl)-2-methyl-1H-benzimidazole-5-carboxylic acid Carboxylic acid having a heterocyclic ring; And the like. Among these, carboxylic acids having a heterocycle containing two or more nitrogen atoms are preferred, and carboxylic acids having an imidazole structure are more preferred from the viewpoint of the high effect of improving ODF unevenness and the voltage retention rate. In addition, the specific carboxylic acid (mc-1) can be used alone or in combination of two or more.

As for the carboxylic acid to be reacted with the epoxy group-containing polyorganosiloxane, the specific carboxylic acid (mc-1) may be used alone, or other carboxylic acids other than the specific carboxylic acid (mc-1) may be used in combination. Examples of the other carboxylic acids include formic acid, acetic acid, propionic acid, benzoic acid, methylbenzoic acid, (meth)acrylic acid, alkyl (meth)acrylate, and carboxylic acid containing an orientation group described in the method (1). . In addition, "(meth)acryl" in this specification is the meaning including acrylic and methacrylic.

[Reaction of epoxy group-containing polyorganosiloxane and carbonic acid]

The reaction of the epoxy group-containing polyorganosiloxane and the carboxylic acid can be preferably carried out in the presence of a catalyst and an organic solvent.

The ratio of carbon acids used in the above reaction (in the case of using two or more types, the total amount) is preferably 5 mol% or more, more preferably 10% by mole with respect to the epoxy group of the epoxy group-containing polyorganosiloxane. It is -90 mol%, More preferably, it is 15-80 mol%.

In addition, the ratio of the oriented group-containing carboxylic acid used in the methods (1) and (2) is preferably 1 to 80 mol% with respect to the silicon atom of the epoxy group-containing polyorganosiloxane, and 3 to It is more preferable to set it as 70 mol%, and it is still more preferable to set it as 5 to 50 mol%. The proportion of the specific carboxylic acid (mc-1) used in the method (2) is preferably 0.3 to 20 mol%, and 0.5 to 15 mol% with respect to the silicon atom of the epoxy group-containing polyorganosiloxane. It is more preferable to do it.

As the catalyst used for the reaction, a known compound or the like can be used as a so-called curing accelerator for accelerating the reaction of an organic base or an epoxy compound.

Examples of the organic base include primary to secondary organic amines such as ethylamine, diethylamine, piperazine, piperidine, pyrrolidine, and pyrrole; Tertiary organic amines such as triethylamine, tri-n-propylamine, tri-n-butylamine, pyridine, 4-dimethylaminopyridine, and diazabicycloundecene; Quaternary organic amines such as tetramethylammonium hydroxide; And the like. As the organic base, among these, a tertiary organic amine or a quaternary organic amine is preferred.

In addition, examples of the curing accelerator include tertiary amines, imidazole compounds, organophosphorus compounds, quaternary phosphonium salts, diazabicycloalkenes, organometallic compounds such as zinc octylate, quaternary ammonium salts, boron compounds, and metals. Halogen compounds, high melting point dispersion type latent curing accelerators, microcapsule type latent curing accelerators, thermocationic polymerization type latent curing accelerators, and the like. Among these, preferred is a quaternary ammonium salt, and specific examples thereof include tetraethylammonium bromide, tetra-n-butylammonium bromide, tetraethylammonium chloride, and tetra-n-butylammonium chloride.

The catalyst is used in an amount of preferably 100 parts by weight or less, more preferably 0.01 to 100 parts by weight, and still more preferably 0.1 to 20 parts by weight, based on 100 parts by weight of the epoxy group-containing polyorganosiloxane.

Examples of the organic solvent used in the reaction between the epoxy group-containing polyorganosiloxane and the carboxylic acid include a hydrocarbon compound, an ether compound, an ester compound, a ketone compound, an amide compound, and an alcohol compound. Among these, ether compounds, ester compounds, and ketone compounds are preferred from the viewpoints of solubility of raw materials and products and ease of purification of products, and as specific examples of particularly preferred solvents, 2-butanone, 2-hexanone, and methyl iso Butyl ketone, butyl acetate, etc. are mentioned. The organic solvent is preferably used in a ratio such that the solid content concentration (the ratio of the total weight of components other than the solvent in the reaction solution to the total weight of the solution) is 0.1% by weight or more, and 5 to 50% by weight. It is more preferable to use it in a ratio of.

The reaction temperature is preferably 0 to 200°C, more preferably 50 to 150°C. The reaction time is preferably 0.1 to 50 hours, more preferably 0.5 to 20 hours. In addition, after completion of the reaction, it is preferable to wash the organic solvent layer separated from the reaction solution with water. After washing, the organic solvent layer is dried with an appropriate drying agent as necessary, and then the solvent is removed, whereby the target polyorganosiloxane can be obtained.

<Method (3)>

In the method (3), the specific silane compound (ms-1) used in the synthesis of the specific polyorganosiloxane (A), and the types and blending ratios of other silane compounds, apply the description of the method (1) above. I can.

In the method (3), a solution containing the target polyorganosiloxane can be obtained by preparing a dicarboxylic acid added to alcohol in advance, mixing and heating this solution and a silane compound.

Examples of the dicarboxylic acid used in the synthesis include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, phthalic acid, isophthalic acid, terephthalic acid, and the like. It is desirable. Particularly preferred is oxalic acid. The ratio of dicarboxylic acid to be used is preferably such that the amount of carboxyl groups per mole of the total alkoxy groups of the silane compound used in the reaction is 0.2 to 2 moles.

Examples of alcohols used in the reaction include methanol, ethanol, propanol, n-butanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and the like. have. The ratio of the alcohol to be used is preferably 10 to 10,000 parts by weight, more preferably 50 to 1,000 parts by weight, based on 100 parts by weight of the total silane compound used in the reaction.

In the above reaction, the heating temperature is preferably 50 to 180°C. The heating time can be, for example, from several tens of minutes to several tens of hours.

In this way, a reaction solution containing a specific polyorganosiloxane (A) is obtained. This reaction solution may be provided as it is for preparation of a liquid crystal aligning agent, and after concentrating or diluting a reaction solution as needed, you may provide for preparation of a liquid crystal aligning agent. In addition, when the specific polyorganosiloxane (A) obtained by the above reaction has an epoxy group, the above-described oriented group-containing carboxylic acid may be further reacted with the specific polyorganosiloxane (A). By this reaction, the specific polyorganosiloxane (A) having the above-described orientation group can be obtained. The description of the method (2) can be applied to various conditions such as a catalyst and an organic solvent used for the reaction of the specific polyorganosiloxane (A) with the carboxylic acid containing an orientation group, and the reaction temperature and reaction time.

<Method (4)>

Examples of the epoxy group-containing silane compound used in the synthesis of the epoxy group-containing polyorganosiloxane in the method (4) include compounds exemplified as the epoxy group-containing alkoxysilanes in the method (1). In addition, when synthesizing the epoxy group-containing polyorganosiloxane, an epoxy group-containing silane compound may be used alone, or other silane compounds other than the epoxy group-containing silane compound may be used in combination. Examples of the other silane compounds include compounds exemplified as other silane compounds in the method (1) and the specific silane compound (ms-1).

The description of the above method (3) can be applied to various conditions such as the type and amount of dicarboxylic acid and alcohol used in the synthesis of the epoxy group-containing polyorganosiloxane, and the reaction temperature and reaction time. In addition, the description of method (2) can be applied to various conditions such as the type and amount of carbonic acid reacted with the epoxy group-containing polyorganosiloxane, the catalyst and organic solvent used for the reaction, and the reaction temperature and reaction time. have.

As for the specific polyorganosiloxane (A) to be contained in the liquid crystal aligning agent of the present invention, the weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC) is preferably 500 to 100,000, and is 1,000 to 30,000. It is more preferable.

≪Other ingredients≫

The liquid crystal aligning agent of this invention may contain other components other than the said specific polyorganosiloxane (A) as needed together with the said specific polyorganosiloxane (A). As such other components, the liquid crystal aligning agent of the present invention preferably contains at least one polymer (P) selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide.

<Polymer (P)>

[Polyamic acid]

The polyamic acid in the present invention can be synthesized by, for example, reacting tetracarboxylic dianhydride and diamine.

・Tetracarboxylic acid dianhydride

Examples of the tetracarboxylic dianhydride used in the synthesis of polyamic acid include aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, and aromatic tetracarboxylic dianhydride. As specific examples of these, examples of the aliphatic tetracarboxylic dianhydride include 1,2,3,4-butanetetracarboxylic dianhydride and the like;

As alicyclic tetracarboxylic acid dianhydride, for example, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 1,3,3a,4, 5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione, 1,3,3a,4 ,5,9b-hexahydro-8-methyl-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione, 3- Oxabicyclo[3.2.1]octane-2,4-dione-6-spiro-3'-(tetrahydrofuran-2',5'-dione), 5-(2,5-dioxotetrahydro-3 -Furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 3,5,6-tricarboxy-2-carboxymethylnorbornane-2:3,5:6-2 anhydride, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-2 anhydride, 4,9-dioxatricyclo[5.3.1.0 ^2,6 ]undecan-3 ,5,8,10-tetraone, cyclohexanetetracarboxylic dianhydride, etc.;

Examples of the aromatic tetracarboxylic dianhydride include pyromellitic dianhydride and the like;

In addition to those mentioned respectively, tetracarboxylic acid dianhydride and the like described in Japanese Unexamined Patent Publication No. 2010-97188 can be used. Further, the tetracarboxylic dianhydride may be used alone or in combination of two or more.

As the tetracarboxylic dianhydride used to synthesize polyamic acid, it is preferable to use an alicyclic tetracarboxylic dianhydride alone, or a mixture of an alicyclic tetracarboxylic dianhydride and an aromatic tetracarboxylic dianhydride. Do. In the latter case, the alicyclic tetracarboxylic dianhydride is preferably 20 mol% or more, and more preferably 40 mol% or more with respect to the total amount of the tetracarboxylic dianhydride used for synthesis.

·Diamine

Examples of diamines used in the synthesis of polyamic acids include aliphatic diamines, alicyclic diamines, aromatic diamines, diaminoorganosiloxanes, and the like. As specific examples of these, as aliphatic diamines, for example, metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, and the like; Examples of alicyclic diamines include 1,4-diaminocyclohexane, 4,4'-methylenebis(cyclohexylamine), 1,3-bis(aminomethyl)cyclohexane, and the like;

As aromatic diamine, for example, dodecanoxydiaminobenzene, tetradecanoxydiaminobenzene, pentadecaneoxydiaminobenzene, hexadecanoxydiaminobenzene, octadecanoxydiaminobenzene, cholestanyloxy-3,5- Diaminobenzene, cholesteryloxy-3,5-diaminobenzene, cholestanyloxy-2,4-diaminobenzene, cholesteryloxy-2,4-diaminobenzene, 3,5-diaminobenzoic acid Cholestanyl, 3,5-diaminobenzoic acid cholesteryl, 3,5-diaminobenzoic acid ranostanyl, 3,6-bis(4-aminobenzoyloxy)cholestane, 3-(3,5-diamino Benzoyloxy) cholestan, 3,6-bis(4-aminophenoxy) cholestan, 1,1-bis(4-((aminophenyl)methyl)phenyl)-4-butylcyclohexane, 1,1-bis (4-((aminophenyl)methyl)phenyl)-4-heptylcyclohexane, 1,1-bis(4-((aminophenoxy)methyl)phenyl)-4-heptylcyclohexane, 1,1-bis( 4-((aminophenyl)methyl)phenyl)-4-(4-heptylcyclohexyl)cyclohexane, N-(2,4-diaminophenyl)-4-(4-heptylcyclohexyl)benzamide, the following formula (D-1):

(In formula (D-1), X ^I and X ^II are each independently a single bond, -O-, -COO-, or -OCO-, R ^I is an alkanediyl group having 1 to 3 carbon atoms, and R ^Ⅱ is a single bond or 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 d is 0 or 1; provided that a And b are never 0 at the same time)

Diamine containing an orientation group, such as a compound represented by:

p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfide, 4-aminophenyl-4'-aminobenzoate, 1,5-diaminonaphthalene, 2 ,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 2,7-diaminofluorene, 4, 4'-diaminodiphenylether, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 9,9-bis(4-aminophenyl)fluorene, 2,2-bis[4- (4-aminophenoxy)phenyl]hexafluoropropane, 2,2-bis(4-aminophenyl)hexafluoropropane, 4,4'-(p-phenylenediisopropylidene)bisaniline, 4,4 '-(m-phenylenediisopropylidene)bisaniline, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 2,6-diamino Pyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminoacridine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N,N'-bis(4-aminophenyl)-benzidine, N,N'-bis(4- Aminophenyl)-N,N'-dimethylbenzidine, 1,4-bis-(4-aminophenyl)-piperazine, 3,5-diaminobenzoic acid, 1-(4-aminophenyl)-2,3-di Hydro-1,3,3-trimethyl-1H-inden-5-amine, 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-inden-6-amine, etc. of;

Examples of the diaminoorganosiloxane include 1,3-bis(3-aminopropyl)-tetramethyldisiloxane and the like; In addition to those mentioned respectively, the diamine described in Japanese Unexamined Patent Application Publication No. 2010-97188 can be used. Diamine can be used individually by these 1 type or in combination of 2 or more types.

^{As a divalent group represented by "-X I} -(R ^I -X ^II ) _d -" in the above formula (D-1), an alkanediyl group having 1 to 3 carbon atoms, *-O-, *-COO- Or, it is preferable that it is *-OC ₂ H ₄ -O- (however, the bond hand to which "*" is attached is bonded with a diaminophenyl group). Specific examples of the group "-C _c H _{2c +1} " include, for example, methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group , n-nonadecyl group, n-eicosyl group, etc. are mentioned. It is preferable that the two amino groups in the diaminophenyl group are at the 2,4-position or the 3,5-position with respect to the other groups.

As a specific example of the compound represented by said formula (D-1), the compound etc. which are represented by each of following formula (D-1-1)-(D-1-3) are mentioned, for example.

<Synthesis of polyamic acid>

Polyamic acid can be obtained by reacting tetracarboxylic dianhydride and diamine as described above together with a molecular weight modifier, if necessary. The ratio of tetracarboxylic dianhydride and diamine used in the synthesis reaction of polyamic acid is preferably 0.2 to 2 equivalents of acid anhydride groups of tetracarboxylic dianhydride with respect to 1 equivalent of amino group of diamine, and 0.3 A ratio of -1.2 equivalents is more preferable.

Examples of the molecular weight modifier include acid monohydrides such as maleic anhydride, phthalic anhydride, and itaconic anhydride, monoamine compounds such as aniline, cyclohexylamine, and n-butylamine, and monoisocyanates such as phenyl isocyanate and naphthyl isocyanate. Compounds, etc. are mentioned. The ratio of the molecular weight modifier to be used is preferably 20 parts by weight or less, and more preferably 10 parts by weight or less with respect to 100 parts by weight of the total of tetracarboxylic dianhydride and diamine to be used.

The synthesis reaction of the polyamic acid is preferably performed in an organic solvent. The reaction temperature at this time is preferably -20°C to 150°C, and more preferably 0 to 100°C. Moreover, 0.1 to 24 hours are preferable and, as for reaction time, 0.5 to 12 hours are more preferable.

Examples of the organic solvent used in the reaction include aprotic polar solvents, phenolic solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons, and hydrocarbons. Among these organic solvents, at least one selected from the group consisting of aprotic polar solvents and phenolic solvents (organic solvents of the first group), or at least one selected from organic solvents of the first group, and alcohol, It is preferable to use a mixture with at least one selected from the group consisting of ketones, esters, ethers, halogenated hydrocarbons and hydrocarbons (organic solvents of the second group). In the latter case, the ratio of the organic solvents of the second group to be used is preferably 50% by weight or less, more preferably 40% by weight or less with respect to the total amount of the organic solvents of the first group and the organic solvents of the second group. And more preferably 30% by weight or less.

Particularly preferably, N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphotria One or more selected from the group consisting of mid, m-cresol, xylenol and halogenated phenol is used as a solvent, or a mixture of one or more of these and other organic solvents is used within the range of the above ratio. desirable.

The amount (a) of the organic solvent used is preferably an amount such that the total amount (b) of tetracarboxylic dianhydride and diamine is 0.1 to 50% by weight with respect to the total amount (a+b) of the reaction solution.

As described above, a reaction solution obtained by dissolving polyamic acid is obtained. This reaction solution may be provided as it is for preparation of a liquid crystal aligning agent, may be provided for preparation of a liquid crystal aligning agent after isolating the polyamic acid contained in the reaction solution, or preparation of a liquid crystal aligning agent after purifying the isolated polyamic acid You may provide it to. Isolation and purification of the polyamic acid can be performed according to a known method.

<Polyamic acid ester>

The polyamic acid ester in the present invention is, for example, [I] a method of synthesizing by reacting a polyamic acid obtained by the above synthesis reaction with a hydroxyl group-containing compound, a halide, an epoxy group-containing compound, and the like, [II] tetracarbon It can be obtained by a method of reacting an acid diester and a diamine, a method of reacting a [III] tetracarboxylic acid diester dihalide and a diamine, or the like.

Here, examples of the hydroxyl group-containing compound used in the method [I] include alcohols such as methanol, ethanol, and propanol; Phenols, such as phenol and cresol, etc. are mentioned. Further, examples of the halide include methyl bromide, ethyl bromide, stearyl bromide, methyl chloride, stearyl chloride, 1,1,1-trifluoro-2-iodoethane, etc., and epoxy group-containing compounds Examples of examples include propylene oxide.

The tetracarboxylic acid diester used in the method [II] can be obtained, for example, by ring-opening the tetracarboxylic acid dianhydride exemplified in the synthesis of the above polyamic acid using the above alcohols. The reaction of method [II] is preferably carried out in the presence of an appropriate dehydration catalyst. As a dehydration catalyst, for example, 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium halide, carbonylimidazole, phosphorus-based condensing agent, etc. Can be lifted. The tetracarboxylic acid diester dihalide used in method [III] can be obtained, for example, by reacting the tetracarboxylic acid diester obtained as described above with a suitable chlorinating agent such as thionyl chloride.

As the diamine used in the method [II] and method [III], the diamine illustrated in the synthesis of polyamic acid can be mentioned. Further, the polyamic acid ester may have only a dark acid ester structure, or may be a partial esterified product in which the dark acid structure and the dark acid ester structure coexist.

<Polyimide>

The polyimide contained in the liquid crystal aligning agent of the present invention can be obtained, for example, by dehydrating and cyclizing the polyamic acid synthesized as described above to imidize.

The polyimide may be a complete imidide obtained by dehydrating and cyclizing all of the mental acid structure of the precursor polyamic acid, or a partial imide in which only a part of the mental acid structure is dehydrated and cyclized, so that the dark acid structure and the imide ring structure coexist. It may be good. From the viewpoint of electrical properties, the polyimide in the present invention preferably has an imidation ratio of 30% or more, more preferably 50 to 99%, and still more preferably 65 to 99%. This imidation ratio is a percentage showing the ratio of the number of imide ring structures to the sum of the number of mental acid structures of the polyimide and the number of imide ring structures. Here, a part of the imide ring may be an isoimide ring.

The dehydration ring closure of the polyamic acid is preferably carried out by a method of heating the polyamic acid or by dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydration ring closure catalyst to this solution, and heating if necessary. All. Among these, the latter method is preferred.

In the method of adding a dehydrating agent and a dehydration ring closure catalyst to the polyamic acid solution, an acid anhydride such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride can be used as the dehydrating agent. The ratio of the dehydrating agent to be used is preferably 0.01 to 20 mol with respect to 1 mol of the mental acid structure of the polyamic acid. As the dehydration ring closure catalyst, tertiary amines, such as pyridine, collidine, lutidine, and triethylamine, can be used, for example. The ratio of the dehydration ring closure catalyst to be used is preferably 0.01 to 10 mol with respect to 1 mol of the dehydrating agent to be used. Examples of the organic solvent used in the dehydration ring closure reaction include organic solvents used for synthesis of polyamic acid. The reaction temperature of the dehydration ring closure reaction is preferably 0 to 180°C, more preferably 10 to 150°C. The reaction time is preferably 1.0 to 120 hours, more preferably 2.0 to 30 hours.

In this way, a reaction solution containing polyimide is obtained. This reaction solution may be provided as it is for preparation of a liquid crystal aligning agent, and after removing a dehydrating agent and a dehydration ring closure catalyst from a reaction solution, it may be provided for preparation of a liquid crystal aligning agent, and after isolating a polyimide, it is provided for preparation of a liquid crystal aligning agent Alternatively, after purifying the isolated polyimide, it may be provided for preparation of a liquid crystal aligning agent. These purification operations can be performed according to known methods.

When the polyamic acid, polyamic acid ester and polyimide obtained as described above are made into a solution having a concentration of 10% by weight, it is preferable to have a solution viscosity of 10 to 800 mPa·s, and a solution viscosity of 15 to 500 mPa·s. It is more preferable to have. In addition, the solution viscosity (mPa·s) of the polymer is a polymer having a concentration of 10% by weight prepared using a good solvent (for example, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.) of the polymer. The solution was measured at 25°C using an E-type rotational viscometer. For polyamic acid, polyamic acid ester, and polyimide, the weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC) is preferably 500 to 300,000, and more preferably 1,000 to 200,000.

The ratio of the specific polyorganosiloxane (A) and the polymer (P) to be blended is the ratio of the specific polyorganosiloxane (A) to the total amount of the specific polyorganosiloxane (A) and the polymer (P) by 2 weight. It is preferable to set it as% or more. By setting it as 2% by weight or more, the effect of suppressing the occurrence of ODF unevenness can be sufficiently obtained. More preferably, it is 4-50 weight%, More preferably, it is 5-40 weight%.

As other components that may be contained in the liquid crystal aligning agent of the present invention, in addition to the polymer (P), for example, other polymers other than the polymer (P), a compound having at least one epoxy group in the molecule (hereinafter, ``epoxy group Containing compound"), a functional silane compound, etc. are mentioned.

[Other polymers]

Other polymers described above can be used to improve solution properties or electrical properties. Examples of such other polymers include polyorganosiloxanes, polyesters, polyamides, cellulose derivatives, polyacetals, polystyrene derivatives, poly(styrenephenylmaleimide) derivatives, poly( Meth)acrylate, etc. are mentioned. When other polymers are added to the liquid crystal aligning agent, the blending ratio is preferably 50% by weight or less, more preferably 0.1 to 40% by weight, and further 0.1 to 30% by weight based on the total amount of the polymer in the composition. desirable.

[Epoxy group-containing compound]

The epoxy group-containing compound can be used in order to improve adhesiveness and electrical properties with the substrate surface in the liquid crystal aligning film. Here, as the epoxy group-containing compound, for example, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglyci Dyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, 2,2-dibromoneopentyl glycoldi Glycidyl ether, N,N,N',N'-tetraglycidyl-m-xylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N, N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, N,N-diglycidyl-benzylamine, N,N-diglycidyl-aminomethylcyclohexane, N, Examples of preferable examples include N-diglycidyl-cyclohexylamine. In addition, as an example of the epoxy group-containing compound, the epoxy group-containing polyorganosiloxane described in International Publication No. 2009/096598 can also be used.

When these epoxy group-containing compounds are added to the liquid crystal aligning agent, the blending ratio is preferably 40 parts by weight or less, and more preferably 0.1 to 30 parts by weight with respect to 100 parts by weight of the total of the polymers contained in the liquid crystal aligning agent.

[Functional silane compound]

The functional silane compound can be used for the purpose of improving the printability of a liquid crystal aligning agent. Examples of such functional silane compounds include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, and N-(2 -Aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxy Silane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-triethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 9-tri Methoxysilyl-3,6-diazanonyl acetate, 9-trimethoxysilyl-3,6-methyl diazanonanoate, N-benzyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyl Trimethoxysilane, glycidoxymethyltrimethoxysilane, 2-glycidoxyethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and the like.

When these functional silane compounds are added to the liquid crystal aligning agent, the blending ratio is preferably 2 parts by weight or less, and more preferably 0.02 to 0.2 parts by weight with respect to the total 100 parts by weight of the polymer.

Examples of the other components include, in addition to the above, compounds having at least one oxetanyl group in the molecule, bismaleimide compounds, antioxidants, and the like. The types and blending amounts of these components can be appropriately adjusted within a range that does not impair the effects of the present invention.

<Solvent>

The liquid crystal aligning agent of the present invention is prepared as a liquid composition obtained by dispersing or dissolving the specific polyorganosiloxane (A) and other components blended as necessary, preferably in a suitable organic solvent.

As a solvent used, for example, N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N,N-dimethylformamide, N,N-dimethylacetamide, 4-hydroxy -4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxy propionate, ethyl ethoxy propionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n -Propyl ether, ethylene glycol-i-propyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, Diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, dipropylene glycol monomethyl ether (DPM), diisobutyl ketone, isoamyl propionate , Isoamyl isobutyrate, diisopentyl ether, ethylene carbonate, and propylene carbonate. These may be used alone or in combination of two or more.

The solid content concentration in the liquid crystal aligning agent of the present invention (the ratio of the total weight of the components other than the solvent of the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) is appropriately selected in consideration of viscosity and volatility, but is preferably It is in the range of 1 to 10% by weight. That is, the liquid crystal aligning agent of the present invention is applied to the substrate surface as described later, and preferably heated to form a coating film serving as a liquid crystal aligning film or a coating film serving as a liquid crystal aligning film, but at this time, when the solid content concentration is less than 1% by weight And, the film thickness of this coating film becomes insufficient, and it is difficult to obtain a good liquid crystal aligning film. On the other hand, when the solid content concentration exceeds 10% by weight, the film thickness of the coating film becomes excessive, making it difficult to obtain a good liquid crystal aligning film, and the viscosity of the liquid crystal aligning agent increases, resulting in inferior coating properties.

The range of a particularly preferable solid content concentration differs depending on the method used when applying the liquid crystal aligning agent to the substrate. For example, in the case of spinner method, the range of 1.5 to 4.5% by weight of solid content concentration is particularly preferable. In the case of the printing method, it is particularly preferable to set the solid content concentration in the range of 3 to 9% by weight, and thus the solution viscosity to be in the range of 12 to 50 mPa·s. In the case of the ink jet method, it is particularly preferable to set the solid content concentration in the range of 1 to 5% by weight, and accordingly, the solution viscosity to be in the range of 3 to 15 mPa·s. The temperature when preparing the liquid crystal aligning agent of the present invention is preferably 10 to 50°C, more preferably 20 to 30°C.

<Liquid crystal alignment film and liquid crystal display element>

The liquid crystal aligning film of this invention is formed by the liquid crystal aligning agent prepared above. Moreover, the liquid crystal display element of this invention is equipped with the liquid crystal aligning film formed using the said liquid crystal aligning agent. The driving mode of the liquid crystal display element is not particularly limited, and can be applied to various driving modes such as TN type, STN type, IPS type, FFS type, VA type, and MVA type. Preferably, it is a vertical alignment type liquid crystal display element, such as VA type and MVA type.

The liquid crystal display device of the present invention can be manufactured, for example, by a method including the following steps (1) to (3). In step (1), the substrate to be used is different depending on the desired driving mode. Process (2) and process (3) are common to each drive mode.

[Step (1): Formation of coating film]

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

(1-1) When manufacturing a TN-type, STN-type, VA-type, or MVA-type liquid crystal display element, use as a pair of two substrates on which a patterned transparent conductive film is formed, and transparent conduction in each substrate. On the formation surface of the film, the liquid crystal aligning agent of the present invention is preferably applied by an offset printing method, a spin coating method, a roll coater method, or an inkjet printing method, respectively. Here, as the substrate, for example, glass such as float glass and soda glass; A transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, and poly(alicyclic olefin) can be used. As the transparent conductive film formed on one side of the substrate, a _{NESA film made of tin oxide (SnO 2} ) (registered trademark of PPG in the United States), an _{ITO film made of indium oxide-tin oxide (In 2} O ₃ -SnO ₂ ), etc. may be used. I can. To obtain a patterned transparent conductive film, for example, a method of forming a pattern by photo etching after forming a transparent conductive film without a pattern, a method of using a mask having a desired pattern when forming a transparent conductive film, etc. can be employed. . When applying the liquid crystal aligning agent, in order to further improve the adhesion between the substrate surface and the transparent conductive film and the coating film, a functional silane compound, a functional titanium compound, and the like are previously applied to the surface of the substrate surface where the coating film is formed. Pre-application treatment may be performed.

After the liquid crystal aligning agent is applied, pre-heating (prebaking) is preferably performed for the purpose of preventing liquid flow of the applied aligning agent. The prebaking temperature is preferably 30 to 200°C, more preferably 40 to 150°C, and particularly preferably 40 to 100°C. The prebaking time is preferably 0.25 to 10 minutes, more preferably 0.5 to 5 minutes. Thereafter, a firing (post-baking) process is performed for the purpose of completely removing the solvent and, if necessary, for thermal imidization of the dark acid structure present in the polymer. The firing temperature (post-baking temperature) at this time is preferably 80 to 300°C, more preferably 120 to 250°C. The post-baking time is preferably 5 to 200 minutes, more preferably 10 to 100 minutes. The film thickness of the film thus formed is preferably 0.001 to 1 µm, more preferably 0.005 to 0.5 µm.

(1-2) In the case of manufacturing an IPS-type or FFS-type liquid crystal display device, an electrode-forming surface of a substrate on which an electrode made of a transparent conductive film or a metal film patterned in a comb-tooth pattern is formed, and the opposite electrode is not formed. A coating film is formed by applying the liquid crystal aligning agent of the present invention to one surface of the substrate, and then heating each coating surface. The material of the substrate and the transparent conductive film used at this time, the coating method, the heating conditions after application, the patterning method of the transparent conductive film or metal film, the pretreatment of the substrate, and the preferable film thickness of the formed coating film are the same as in (1-1) above. . As the metal film, for example, a film made of a metal such as chromium can be used.

In any of the above (1-1) and (1-2), after applying the liquid crystal aligning agent on the substrate, the organic solvent is removed to form a coating film serving as an alignment film. At this time, in the case where the polymer contained in the liquid crystal aligning agent of the present invention is a polyamic acid, a polyamic acid ester, or an imidized polymer having an imide ring structure and a dark acid structure, the dehydration ring closure reaction proceeds by additional heating after the coating film is formed. It may be made into a more imidized coating film.

[Step (2): rubbing treatment]

In the case of manufacturing a TN-type, STN-type, IPS-type or FFS-type liquid crystal display device, the coating film formed in the above step (1) is rolled with a cloth made of fibers such as nylon, rayon, and cotton in a certain direction. Rubbing treatment is performed. As a result, the alignment ability of the liquid crystal molecules is imparted to the coating film to form a liquid crystal alignment film. On the other hand, in the case of manufacturing a vertically aligned liquid crystal display element, the coating film formed in the above step (1) can be used as it is as a liquid crystal alignment film, but a rubbing treatment may be performed on the coating film. In addition, with respect to the liquid crystal alignment film after rubbing treatment, treatment of changing the pretilt angle of a part of the liquid crystal alignment film by irradiating ultraviolet rays to a part of the liquid crystal alignment film, or after forming a resist film on a part of the liquid crystal alignment film surface, After performing the rubbing treatment in a direction different from that of the rubbing treatment, a treatment for removing the resist film may be performed so that the liquid crystal alignment film has a different liquid crystal alignment ability for each region. In this case, it is possible to improve the viewing characteristics of the obtained liquid crystal display element. A liquid crystal alignment film suitable for a vertical alignment type liquid crystal display element can also be suitably used for a PSA (Polymer sustained alignment) type liquid crystal display element.

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

(3-1) A liquid crystal cell is produced by preparing two substrates on which a liquid crystal aligning film is formed in the manner described above, and disposing a liquid crystal between the two substrates arranged opposite to each other. In order to manufacture a liquid crystal cell, a vacuum injection method and an ODF method are mentioned, for example. In the vacuum injection method, first, two substrates are opposed to each other through a gap (cell gap) so that the respective liquid crystal aligning films face each other, and the peripheries of the two substrates are bonded using a sealing agent, and the substrate surface and the sealing agent After filling the liquid crystal in the cell gap partitioned by, the injection hole is sealed to prepare a liquid crystal cell. In the ODF method, for example, an ultraviolet light-curable sealing agent is applied to a predetermined place on one of the two substrates on which the liquid crystal aligning film is formed, and additionally, at several predetermined places on the surface of the liquid crystal aligning film. After dropping the liquid crystal, the other substrate is bonded so that the liquid crystal aligning film faces. Then, the liquid crystal is spread over the entire surface of the substrate, and then the entire surface of the substrate is irradiated with ultraviolet light to cure the sealing agent to produce a liquid crystal cell. In any case, it is preferable to remove the flow orientation at the time of liquid crystal filling by further heating the liquid crystal cell produced as described above to a temperature at which the used liquid crystal takes an isotropic phase, and then gradually cools it to room temperature. Do.

As the sealing agent, for example, an epoxy resin containing aluminum oxide spheres as a curing agent and a spacer can be used. Moreover, as a liquid crystal, a nematic liquid crystal and a smectic liquid crystal are mentioned, Among them, a nematic liquid crystal is preferable. For example, a ciprobase liquid crystal, an azocyclic liquid crystal, a biphenyl liquid crystal, a phenylcyclohexane liquid crystal, and an ester Liquid crystals, terphenyl liquid crystals, biphenylcyclohexane liquid crystals, pyrimidine liquid crystals, dioxane liquid crystals, bicyclooctane liquid crystals, cuban liquid crystals, and the like can be used. In addition, in these liquid crystals, for example, cholesteryl chloride, cholesteryl nonarate, cholesteryl carbonate, and the like cholesteric liquid crystals; Chiral agents as sold under the brand names "C-15" and "CB-15" (manufactured by Merck); Strong dielectric liquid crystals, such as p-decyloxybenzylidene-p-amino-2-methylbutyl cinnamate, etc. may be added and used.

And by bonding a polarizing plate to the outer surface of a liquid crystal cell, the liquid crystal display element of this invention can be obtained. Examples of the polarizing plate bonded to the outer surface of the liquid crystal cell include a polarizing plate made of an H film itself or a polarizing plate in which a polarizing film called ``H film'' absorbed iodine while stretching and aligning polyvinyl alcohol is sandwiched by a cellulose acetate protective film. have. In addition, when rubbing treatment is performed on the coating film, the two substrates are arranged to face each other so that the rubbing directions in the respective coating films are at a predetermined angle, for example, perpendicular or antiparallel.

The liquid crystal display device of the present invention can be effectively applied to various devices, for example, a watch, a portable game, a word processor, a notebook computer, a car navigation system, a camcorder, a PDA, a digital camera, a mobile phone, and a smart device. It can be used for various display devices such as phones, various monitors, liquid crystal televisions, and information displays.

(Example)

Hereinafter, the present invention will be described in more detail by examples, but the present invention is not limited to these examples.

The weight average molecular weight of the polymer, the solution viscosity, and the imidation ratio of the polyimide in each of the following synthesis examples were measured by the following methods.

[Measurement of the weight average molecular weight of the polymer]

The weight average molecular weight (Mw) of a polymer is a polystyrene conversion value measured by GPC of the following specifications.

Column: Tosoh Corporation, TSKgelGRCXLII

Solvent: tetrahydrofuran

Temperature: 40℃

Pressure: 68kgf/㎠

[Solution Viscosity of Polymer Solution]

The solution viscosity [mPa·s] of the polymer solution was measured at 25°C using an E-type rotational viscometer with respect to a solution prepared at a polymer concentration of 10% by weight using a predetermined solvent.

[Imidation rate of polyimide]

A polyimide solution was added to pure water, and the obtained precipitate was sufficiently dried under reduced pressure at room temperature, then dissolved in deuterated dimethyl sulfoxide, and ¹ H-NMR was measured at room temperature using tetramethylsilane as a reference substance. It saved the imidization ratio [%] by the following ¹ H-NMR spectrum obtained from the formula indicated by equation (1):

Imidation rate [%] = (1-A ¹ /A ² × α) × 100. (One)

(In formula (1), A ¹ is the peak area derived from the proton of the NH group appearing in the vicinity of 10 ppm of chemical shift, A ² is the peak area derived from other protons, and α is in the precursor (polyamic acid) of the polymer. It is the ratio of the number of other protons to one proton of the NH group).

<Synthesis of polyorganosiloxane containing epoxy group>

[Synthesis Example S-1]

In a reaction vessel equipped with a stirrer, thermometer, dropping funnel, and reflux condenser, 139.0 g of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 139.0 g of methyl isobutyl ketone, and 13.9 g of triethylamine were added. , Mixed at room temperature. Next, 111.2 g of deionized water was added dropwise from the dropping funnel over 30 minutes, and then reacted at 60° C. for 3 hours while mixing under reflux. After completion of the reaction, the organic layer was taken out, washed with a 0.2 wt% ammonium nitrate aqueous solution until the water after washing becomes neutral, and then the solvent and water were distilled off under reduced pressure to remove the epoxy group-containing polyorganosiloxane (S-1 ) Was obtained as a viscous transparent liquid. For this epoxy group-containing polyorganosiloxane (S-1), ¹ H-NMR analysis was performed. As a result, a peak based on the epoxy group was obtained in the vicinity of the chemical shift (δ) = 3.2 ppm according to the theoretical intensity. It was confirmed that no side reaction occurred. The weight average molecular weight (Mw) of the epoxy group-containing polyorganosiloxane (S-1) obtained here was 2,400.

[Synthesis Examples S-2 to S-21]

Transparent liquid in which epoxy group-containing polyorganosiloxanes (S-2) to (S-21) are viscous by performing the same operation as in Synthesis Example S-1 using an alkoxysilane compound in the amount and ratio shown in Table 1 below. Respectively obtained as. About the obtained epoxy group-containing polyorganosiloxane (S-2) to (S-21), ¹ H-NMR analysis was similarly performed, and it was confirmed that no side reaction of the epoxy group occurred during the reaction. Moreover, the weight average molecular weight (Mw) of the epoxy group-containing polyorganosiloxane (S-2)-(S-21) was combined with Table 1, and was shown.

The numerical value of the blending ratio in Table 1 represents the ratio (mol%) used of each compound to the total amount of the monomer used in the synthesis of the epoxy group-containing polyorganosiloxane. The abbreviation of the compound is as shown below.

[Specific silane compounds]

ms-1-1: 2-(2-pyridyl)ethyltrimethoxysilane

ms-1-2: 2-(N-pyrrolyl)ethyltrimethoxysilane

ms-1-3: 3-(2-pyridyl)ureidopropyltriethoxysilane

ms-1-4: 3-(2-imidazolin-1-yl)propyltriethoxysilane

ms-1-5: N-(1H-imidazol-2-yl)methylaminopropyltrimethoxysilane

ms-1-6: N-(4-methyl-1H-imidazol-5-yl)methylaminopropyltrimethoxysilane

ms-1-7: N-(4-methyl-2-phenyl-1H-imidazol-5-yl)methylaminopropyltrimethoxysilane

ms-1-8: N-(2-methyl-1H-imidazol-1-yl)methylaminopropyltrimethoxysilane

ms-1-9: N-(2-phenyl-1H-imidazol-1-yl)methylaminopropyltrimethoxysilane

ms-1-10: 3-(1H-imidazol-1-yl)propan-2-ol-1-oxypropyltrimethoxysilane

ms-1-11: 3-(1H-imidazol-1-yl)propyloxypropyltrimethoxysilane

[Other silane compounds]

ms-2-1: 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane

ms-2-2: 3-methacryloxypropyltrimethoxysilane

ms-2-3: 8-methacryloxyoctyltrimethoxysilane

<Reaction of epoxy group-containing polyorganosiloxane and carbonic acid>

[Synthesis Example A-1]

In a 100 mL 3-neck flask, 56.0 g of the epoxy group-containing polyorganosiloxane (S-1) obtained in Synthesis Example S-1, 206.0 g of methyl isobutyl ketone, 1.8 g of 4-imidazole carboxylic acid, and 4-octyloxy 22.2 g of benzoic acid and 0.6 g of UCAT 18X (quaternary amine salt manufactured by San Apro) were put, and the mixture was stirred at 80°C for 36 hours. After completion of the reaction, reprecipitation was performed with water, and the precipitate was dissolved in ethyl acetate to obtain a solution. After washing this solution three times, the solvent was distilled off to obtain 42.6 g of polyorganosiloxane (A-1) as a white powder. Mw of the polyorganosiloxane (A-1) was 7,200.

[Synthesis Examples A-2 to A-85]

Polyorganosiloxanes (A-2) to (A-) by performing the same operation as in Synthesis Example A-1 using the epoxy group-containing polyorganosiloxane and carboxylic acid in the amounts and ratios shown in Table 2 and Table 3 below. 85) was obtained as a white powder. The weight average molecular weight (Mw) of polyorganosiloxane (A-2)-(A-85) was combined with Table 2 and Table 3, and was shown.

In Tables 2 and 3, the numerical value of the blending ratio of the carboxylic acid represents the amount (mol%) charged with respect to the total amount of silicon atoms in the precursor polyorganosiloxane used in the reaction. The abbreviation of the compound is as shown below.

[Specific carboxylic acid]

mc-1-1: nicotinic acid

mc-1-2: 1-(pyridin-3-yl)cyclopropanecarboxylic acid

mc-1-3: 4-imidazole carboxylic acid

mc-1-4: 4-(1H-imidazol-1-yl)benzoic acid

mc-1-5: 4-[(1H-imidazol-1-yl)methyl]benzoic acid

mc-1-6: 4-[2-(1H-imidazol-1-yl)ethoxy]benzoic acid

mc-1-7: 4-(4,5-diphenyl-1H-imidazol-2-yl)benzoic acid

[Other carboxylic acids]

mc-2-1: 4-octyloxybenzoic acid

mc-2-2: 4-(4-pentylcyclohexyl)benzoic acid

mc-2-3: succinic acid 5ξ-cholestan-3-yl

mc-2-4: (4'-pentylbicyclohexyl-4-yl)carboxylic acid

mc-2-5: 4-(4'-pentylbicyclohexyl-4-yl)benzoic acid

mc-2-6: 4-(4-pentylcyclohexyl)oxidodecanoic acid

mc-2-7: 11-((4'-pentylbicyclohexyl-4-yl)oxy)dodecanoic acid

mc-2-8: 11-(4-(4-pentylcyclohexyl)phenyloxy)dodecanoic acid

[Comparative Synthesis Examples Ao-86 to Ao-93]

Polyorganosiloxanes (Ao-86) to (Ao-93) were prepared in the same manner as in Synthesis Example A-1 using the epoxy group-containing polyorganosiloxane and carboxylic acid in the amounts and ratios shown in Table 4 below. Obtained as a white powder. The weight average molecular weight (Mw) of polyorganosiloxane (Ao-86)-(Ao-93) was combined with Table 4, and was shown. In addition, the numerical value of the compounding ratio of the carbonic acid in Table 4 and the abbreviation of a compound are the same as in Tables 2 and 3 above.

<Synthesis of polyimide>

[Synthesis Example P-1]

As tetracarboxylic acid dianhydride, 189.8 g (0.85 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 74.7 g (0.69 mol) of p-phenylenediamine as diamine compound, and cholestanyloxy-2,4 -85.5 g (0.17 mol) of diaminobenzene was dissolved in 1,400 g of N-methyl-2-pyrrolidone (NMP), and reacted at 60° C. for 6 hours. A small amount of the obtained polyamic acid solution was aliquoted, NMP was added, and the viscosity was measured in a solution having a solid content concentration of 10% by weight, and it was 57 mPa·s. Next, 3,250 g of NMP was added to the obtained polyamic acid solution, 67 g of pyridine and 86 g of acetic anhydride were added, followed by dehydration and ring closure at 110°C for 4 hours. After the imidation reaction, the solvent in the system was replaced with new NMP (the pyridine and acetic anhydride used in the imidation reaction were removed from the system in this operation), and the polyimide (P-1) having an imidation rate of 49% was about A solution containing 15% by weight was obtained. A small amount of the obtained polyimide solution was aliquoted, NMP was added, and the solution viscosity measured as a solution having a polyimide concentration of 10% by weight was 37 mPa·s.

<Preparation and evaluation of liquid crystal aligning agent>

[Example 1]

(1) Preparation of liquid crystal aligning agent

The polyorganosiloxane (A-1) obtained in Synthesis Example A-1 was dissolved in butyl cellosolve (BC) to prepare a polysiloxane solution A-1 having a solid content concentration of 15.0% by weight. Thereafter, the solution containing the polyimide (P-1) obtained in Synthesis Example P-1 and the polysiloxane solution A-1 were mixed with polyimide (P-1): polyorganosiloxane (A-1) = 95. It mixed so that it might become :5 (weight ratio), N-methyl-2-pyrrolidone (NMP) and BC were added to this, and it stirred sufficiently. To this solution, 3 parts by weight of N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane was added with respect to the total 100 parts by weight of the polymer, and the solvent composition was NMP: BC = 60:40 (weight ratio), it was set as the solution of 3.5 weight% of solid content concentration. A liquid crystal aligning agent was prepared by filtering this solution using a filter with a pore diameter of 0.2 µm.

(2) Evaluation of liquid crystal diffusivity

The liquid crystal aligning agent prepared in the above (1) was applied to the transparent electrode surface of a glass substrate with a transparent electrode having an ITO whole surface electrode structure using a liquid crystal alignment film printer (manufactured by Nippon Shashin Insats Co., Ltd.), and then at 80°C. The solvent was removed by heating (prebaking) on a hot plate at 200°C for 10 minutes (postbaking) on a hot plate at 200°C to form a coating film having an average thickness of 800 angstroms. To this substrate, the substrate-liquid crystal contact angle when 7.0 μl of liquid crystal MLC-2038 (manufactured by Merck) was dropped and left for 30 seconds was measured by the θ/2 method using DROPMASTER 700 manufactured by Kyowa Interfacial Chemical Company. did. When the contact angle at this time was less than 15 degrees, the liquid crystal diffusivity was evaluated as "good", and when the contact angle was 15 degrees or more, the liquid crystal diffusivity was evaluated as "poor". As a result, the contact angle of the present coating film was 13 degrees and showed a value of "good".

(3) Preparation of liquid crystal cell

The liquid crystal aligning agent prepared in the above (1) was prepared using a liquid crystal aligning film printer (manufactured by Nippon Shashin Insats Co., Ltd.), a glass substrate with a transparent electrode having a fine slit ITO electrode structure, and a transparent electrode having a patterned ITO electrode structure. After each coating on the transparent electrode surface of the attached glass substrate, heating (pre-baking) for 1 minute on a hot plate at 80°C to remove the solvent, heating (post-baking) on a hot plate at 200°C for 10 minutes, and an average film thickness of 800 Å A coating film of was formed. Each substrate after coating film formation was subjected to ultrasonic cleaning for 1 minute in ultrapure water, and then dried for 10 minutes in a 100°C clean oven. Thereby, a pair (two) of substrates having a liquid crystal aligning film was obtained.

Next, after applying a photocurable epoxy acrylic resin adhesive containing an aluminum oxide spacer having a diameter of 3.5 µm to the outer edge of a coating film-forming substrate having a fine slit ITO electrode structure, a required amount of liquid crystal MLC-6608 was added dropwise. At this time, the liquid crystal was dripped at a plurality of locations on the coating film formation substrate. In addition, the total dropping amount of the liquid crystal was 0.98 times to 1.0 times the volume obtained by the product of the area to which the adhesive was applied and the spacer diameter, and the dropping amount of one point was adjusted between 0.2 and 1.0 g. Subsequently, the substrate to which the liquid crystal was dropped was installed in a vacuum bonding apparatus, and a coating film-forming substrate having a patterned ITO electrode structure was provided on the opposite side of the substrate, and then bonding was performed under vacuum. After completion of bonding, after curing the adhesive portion using 365 nm UV light, annealing was performed in an oven at 120° C. for 1 hour to prepare a liquid crystal cell.

(4) Evaluation of vertical orientation

After the liquid crystal cell prepared above was installed between two polarizing plates arranged in an orthogonal state, the liquid crystal alignment state in the state of no voltage application and an alternating voltage of 60 Hz in the range of 0 to 10.0 V (peak-peak). The liquid crystal alignment state when applied was observed, respectively. Black display is obtained without any defects in the state where no voltage is applied, and the orientation is ``good'' when there are no bright spots or misalignment in the state of voltage application, and ``defective B'' when the bright spot or unevenness is seen in the state where no voltage is applied, and voltage is applied. The case where defects or disorientation were observed in the state was evaluated as the alignment property "defective W". As a result, the vertical alignment property of this liquid crystal cell was "good".

(5) Evaluation of voltage retention rate

After applying a voltage of 5 V to the liquid crystal cell prepared in (3) with an application time of 60 microseconds and a span of 1670 milliseconds, the voltage retention rate after 1670 milliseconds from the release of the application was measured. As a measuring device, a 6517 type liquid crystal physical property measuring device manufactured by Toyo Technica was used. As a result, the voltage retention rate was 99%, showing a good value.

(6) Evaluation of the effect of suppressing ODF heterogeneity

An alternating voltage of 60 Hz was applied to the liquid crystal cell prepared in the above (3) at 4.0 V (peak-peak), and unevenness occurring in the entire liquid crystal cell was observed. When no non-uniformity occurs, it is ``good'', when a non-uniformity occurs at the dropping position of the liquid crystal is ``defective (with dripping marks)'', and when a non-uniformity occurs in the middle of the dropping position of the liquid crystal is ``poor (there is lattice irregularity)'', liquid crystal As a result of evaluating the case where nonuniformity occurred in both the dropping position and the middle of the liquid crystal dropping position as "defective (dropping marks exist, lattice irregularities exist)", the ODF nonuniformity evaluation of this liquid crystal cell was "good".

[Examples 2 to 85]

As shown in Table 5 and Table 6 below, the type and amount of the polyorganosiloxane to be used, and the amount of polyimide (P-1) used, and N,N,N',N'-tetraglycidyl- Except that 4,4'-diaminodiphenylmethane was not mixed, it carried out similarly to Example 1, and prepared the liquid crystal aligning agent, and evaluated. The results are shown in Tables 5 and 6. In addition, the numerical value of the blending ratio of polyimide and polyorganosiloxane represents the blending ratio (parts by weight) of each polymer with respect to the total 100 parts by weight of the polymer component in the liquid crystal aligning agent.

[Comparative Examples 1 to 15]

A liquid crystal aligning agent was prepared and evaluated in the same manner as in Example 1, except that the type and amount of the polyorganosiloxane to be used and the amount of polyimide (P-1) used were as shown in Table 7 below. . The results are summarized and shown in Table 7. In addition, in Table 7, "-" of the evaluation result of ODF non-uniformity shows that an orientation defect has occurred at the time of non-driving, and the evaluation of ODF non-uniformity was not possible.

As shown in Tables 5 and 6, in the liquid crystal aligning agent (Examples 1 to 85) blended with a polyorganosiloxane having a nitrogen-containing heterocyclic structure, liquid crystal diffusivity, vertical alignment, voltage retention, and ODF non-uniformity suppression Both effects showed good results. On the other hand, in the liquid crystal aligning agent (Comparative Examples 1 to 15) not containing the polyorganosiloxane having a nitrogen-containing heterocyclic structure, as shown in Table 7, liquid crystal diffusivity, vertical alignment, and ODF non-uniformity suppression effect Which of them was bad. In addition, for Comparative Examples 2 to 15, the voltage retention rate was as low as 95% or less.

In addition, the reason why the above effect was obtained by blending a polyorganosiloxane having a nitrogen-containing heterocyclic structure is not clear, but one reason is the thermal strengthening property of the film by blending a polyorganosiloxane having a nitrogen-containing heterocyclic structure. As a result of this improvement, resistance to stress to the film surface generated at the time of liquid crystal dropping and the bonding step was increased, it is estimated that the occurrence of ODF non-uniformity could be suppressed.

Claims (7)

It contains a polyorganosiloxane having a heterocyclic structure (a) containing a nitrogen atom in the ring skeleton,
The liquid crystal aligning agent, wherein the heterocyclic structure (a) is an aromatic heterocyclic structure. It contains a polyorganosiloxane having a heterocyclic structure (a) containing a nitrogen atom in the ring skeleton,
The said heterocyclic structure (a) has 2 or more nitrogen atoms in a ring skeleton, The liquid crystal aligning agent characterized by the above-mentioned. The method of claim 1,
The liquid crystal aligning agent in which the said heterocyclic structure (a) has 2 or more nitrogen atoms in a ring skeleton. The method of claim 1,
The liquid crystal aligning agent in which the said heterocyclic structure (a) is an imidazole structure. The method of claim 1,
A liquid crystal aligning agent further containing at least one polymer selected from the group consisting of polyamic acid, polyimide, and polyamic acid ester. A liquid crystal aligning film formed using the liquid crystal aligning agent in any one of Claims 1-5. A liquid crystal display device comprising the liquid crystal alignment film according to claim 6.