JP6260381B2 - Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element - Google Patents

Description

  The present invention relates to a liquid crystal aligning agent, a liquid crystal aligning film, and a liquid crystal display element, and more particularly to a liquid crystal aligning agent that is suitably used for manufacturing a vertical alignment type liquid crystal display element.

  The liquid crystal display element includes a liquid crystal alignment film that 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 the vertical direction. As a material constituting this liquid crystal alignment film, polyamic acid, polyimide, polyamide, polyester, polyorganosiloxane, and the like are known, and in particular, a liquid crystal alignment film made of polyamic acid or polyimide has heat resistance, mechanical strength, liquid crystal It has been used preferably for a long time because of its excellent affinity with molecules (for example, see Patent Document 1). In recent years, a liquid crystal aligning agent containing a polyorganosiloxane obtained by reacting a trifunctional or tetrafunctional hydrolyzable silane compound has been used for reasons such as good light resistance and heat resistance. In some cases (for example, see Patent Documents 2 to 4).

  2. Description of the Related Art In recent years, in a manufacturing process of a liquid crystal display element, there is a liquid crystal dropping method (One Drop Fill method, abbreviated as “ODF method”) as a manufacturing method of a liquid crystal cell that has been adopted with an increase in the size of a substrate. In the ODF method, a required amount of liquid crystal is dropped on a predetermined number of locations on a substrate on which a liquid crystal alignment film is formed, bonded to the other substrate in a vacuum, and the liquid crystal is spread over the entire surface of the substrate. In this method, liquid crystal is filled on the entire surface of the panel by UV-curing a sealing agent for sealing. This method is a technique that can significantly reduce the process time of the liquid crystal filling step as compared with the conventional vacuum injection method. In particular, this method is often used in the manufacture of a vertical alignment type liquid crystal display element used for a large liquid crystal display element such as a television.

JP 2010-97188 A JP-A-9-281502 Japanese Patent No. 4458305 Japanese Patent No. 4458306

  While the liquid crystal display device manufacturing method using the ODF method has the above-described advantages, display unevenness called “ODF unevenness” is likely to occur, which may affect display quality. Due to the recent increase in demand for improving display quality, even finer unevenness may be judged as poor quality, and a technique capable of sufficiently suppressing the occurrence of ODF unevenness is required.

  In recent years, in order to improve the high-speed response of the liquid crystal panel, a liquid crystal having a higher polarity tends to be used. It is known that such an increase in polarity simultaneously increases the content of ionic impurities, leading to a decrease in afterimage characteristics and reliability of the liquid crystal display element. In order to further improve the display quality and reliability of the liquid crystal display element, a liquid crystal display element having a higher level of electrical characteristics, that is, a higher voltage holding ratio is required even when such a high-polarity liquid crystal is used. It has become.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a liquid crystal aligning agent for obtaining a liquid crystal display element capable of suppressing the occurrence of ODF unevenness and having good electrical characteristics. .

  As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by including a polyorganosiloxane having a specific structure in the liquid crystal aligning agent, and complete the present invention. It came to. Specifically, the present invention provides the following liquid crystal aligning agent, liquid crystal alignment film, and liquid crystal display element.

  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 the ring skeleton.

  In another aspect, the present invention provides a liquid crystal alignment film formed using the liquid crystal alignment agent. Moreover, the liquid crystal display element which comprises the said liquid crystal aligning film is provided.

  According to the liquid crystal aligning agent of the present invention, a liquid crystal display element with less ODF unevenness can be obtained when the ODF method is adopted in the manufacturing process of the liquid crystal display element. In addition, by forming a liquid crystal alignment film using the liquid crystal aligning agent of the present invention, a liquid crystal display element having good electrical characteristics can be obtained. Therefore, the liquid crystal aligning agent of the present invention can be preferably applied to the current mass production process of liquid crystal display elements.

  The liquid crystal aligning agent of the present invention contains a polyorganosiloxane having a heterocyclic structure (a) containing a nitrogen atom in the ring skeleton. Below, each component contained in the liquid crystal aligning agent of this invention and the other component arbitrarily mix | blended as needed are demonstrated.

≪Heterocyclic structure (a) ≫
The heterocyclic structure (a) may 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 single ring or a condensed ring. Further, the ring skeleton may contain only a nitrogen atom as a hetero atom, or may contain a nitrogen atom and a hetero atom (oxygen atom, sulfur atom, etc.) other than the nitrogen atom. 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 in different rings. It may be.

Specific examples of the heterocyclic structure (a) include non-aromatic heterocyclic rings such as pyrrolidine, piperidine, piperazine, hexamethyleneimine, imidazoline, morpholine; pyrrole, imidazole, pyrazole, triazole, pyridine, pyrimidine, pyridazine, pyrazine , Indole, benzimidazole, purine, quinoline, isoquinoline, naphthyridine, quinoxaline, phthalazine, triazine, azepine, diazepine, acridine, phenazine, phenanthroline, oxazole, thiazole, carbazole, thiadiazole, benzothiazole, phenothiazine, oxadiazole, etc. And a structure obtained by removing one or more hydrogen atoms from a heterocyclic ring.
In the heterocyclic structure (a), a substituent may be introduced into the atoms constituting the ring skeleton exemplified above. Examples of the substituent include halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom; chain or branched alkyl group having 1 to 20 carbon atoms such as methyl group, ethyl group and propyl group; methoxy group An alkoxy group having 1 to 20 carbon atoms such as ethoxy group and propoxy group; a cycloalkyl group having 6 to 20 carbon atoms such as cyclopentyl group and cyclohexyl group; an aryl group having 6 to 20 carbon atoms such as phenyl group and tolyl group; Etc.

  Of the above, the heterocyclic structure (a) is preferably an aromatic heterocyclic structure, and preferred specific examples thereof include pyrrole, imidazole, pyrazole, triazole, pyridine, pyrimidine, pyridazine, pyrazine, triazine and the like. And a structure in which one or a plurality of hydrogen atoms are removed from the aromatic heterocyclic ring. Among these, the ring skeleton has a plurality of nitrogen atoms in that the effect of suppressing ODF unevenness can be increased by promoting thermosetting during post-baking and the voltage holding ratio can be increased. It is preferable to have two or three. In particular, the heterocyclic structure (a) is preferably an imidazole structure.

≪Specific polyorganosiloxane (A) ≫
The polyorganosiloxane having the heterocyclic structure (a) (hereinafter also referred to as “specific polyorganosiloxane (A)”) can be synthesized by appropriately combining organic chemistry methods. As a specific example, for example,
(1) An alkoxysilane compound having the above heterocyclic structure (a) (hereinafter also referred to as “specific silane compound (ms-1)”), or a specific silane compound (ms-1) and other alkoxysilane compounds A method of hydrolyzing and condensing the mixture;
(2) An epoxy group-containing polysilane by hydrolyzing and condensing an alkoxysilane compound having an epoxy group (hereinafter also referred to as “epoxy group-containing silane compound”) or a mixture of an epoxy group-containing silane compound and other silane compounds. A method of reacting the epoxy group-containing polyorganosiloxane with the carboxylic acid having the heterocyclic structure (a) (hereinafter also referred to as “specific carboxylic acid (mc-1)”) after obtaining the organosiloxane;
(3) A method in which the specific silane compound (ms-1) or a mixture of the specific silane compound (ms-1) and another silane compound is reacted in the presence of a dicarboxylic acid and an alcohol;
(4) The epoxy group-containing silane compound or a mixture of the epoxy group-containing silane compound and another silane compound is reacted in the presence of a dicarboxylic acid and an alcohol to obtain an epoxy group-containing polyorganosiloxane. A method of reacting a group-containing polyorganosiloxane with the specific carboxylic acid (mc-1);
Etc.

<About method (1)>
Examples of the specific silane compound (ms-1) include 2- (2-pyridyl) ethyltrimethoxysilane, 2- (2-pyridyl) ethyltriethoxysilane, 2- (4-pyridyl) ethyltrimethoxysilane, 2 -(4-pyridyl) ethyltriethoxysilane, 2- (N-pyrrolyl) ethyltrimethoxysilane, 2- (2-pyridyl) ethylthiopropyltrimethoxysilane, 2- (4-pyridyl) ethylthiopropyltrimethoxysilane A silane compound having a heterocyclic ring containing one nitrogen atom, such as
3- (2-imidazolin-1-yl) propyltriethoxysilane, N- (1H-imidazol-2-yl) methylaminopropyltrimethoxysilane, N- (4-methyl-1H-imidazol-5-yl) methyl Aminopropyltrimethoxysilane, N- (4-methyl-2-phenyl-1H-imidazol-5-yl) methylaminopropyltrimethoxysilane, N- (2-methyl-1H-imidazol-1-yl) methylaminopropyl Trimethoxysilane, N- (2-phenyl-1H-imidazol-1-yl) methylaminopropyltrimethoxysilane, 3- (1H-imidazol-1-yl) propan-2-ol-1-oxypropyltrimethoxysilane 3- (1H-imidazol-1-yl) propyloxypropyltrime Kishishiran, 3- (2-pyridyl) ureido propyl silane compound having a heterocycle nitrogen atom such as triethoxysilane containing 2 or more;
And so on. 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 in that the effect of suppressing unevenness of ODF is high and the voltage holding ratio can be increased. In addition, a specific silane compound (ms-1) can be used individually by 1 type or in combination of 2 or more types.

In the synthesis of the specific polyorganosiloxane (A) by the method (1), the 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 together. Examples of the other silane compounds include tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, trimethoxysilylpropyl succinic anhydride, dimethyldimethoxysilane, Hydrocarbon side chain-containing alkoxysilanes such as dimethyldiethoxysilane;
3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, mercaptomethyltrimethoxysilane, mercaptomethyltriethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-aminopropyltrimethoxy Alkoxysilanes containing nitrogen and sulfur atoms such as silane, 3-aminopropyltriethoxysilane, N- (3-cyclohexylamino) propyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane ;
3- (meth) acryloyloxypropyltrimethoxysilane, 3- (meth) acryloyloxypropyltriethoxysilane, 6- (meth) acryloyloxyhexyltrimethoxysilane, 8- (meth) acryloyloxyoctyltrimethoxysilane, 3- Unsaturated hydrocarbon-containing alkoxysilanes such as (meth) acryloxypropylmethyldimethoxysilane, 3- (meth) acryloxypropylmethyldiethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, p-styryltrimethoxysilane ;
3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxypropylmethyldimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 3-glycidyloxypropyldimethylmethoxysilane Epoxy group-containing alkoxysilanes such as 3-glycidyloxypropyldimethylethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane;
And so on. Of these, at least one of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidyloxypropyltrimethoxysilane and 8-glycidyloxyoctyltrimethoxysilane is particularly preferably used. Can do. In addition, the said other silane compound can use said thing individually by 1 type or in combination of 2 or more types. In the present specification, “(meth) acryloyl” means acryloyl and methacryloyl.

  When synthesizing the specific polyorganosiloxane (A) by the method (1), the use ratio of the specific silane compound (ms-1) is used in the synthesis in terms of obtaining a sufficient effect of suppressing the occurrence of ODF unevenness and electrical characteristics. It is preferable to set it as 0.5 mol% or more with respect to the whole quantity of the silane compound to perform, It is more preferable to set it as 1-50 mol%, It is still more preferable to set it as 2-30 mol%.

[Hydrolysis / condensation reaction of silane compounds]
The hydrolysis / condensation reaction of the silane compound in the method (1) is carried out by reacting one or more silane compounds as described above with water, preferably in the presence of a suitable catalyst and an organic solvent. Can do.

As said catalyst, an acid, an alkali metal compound, an organic base, a titanium compound, a zirconium compound etc. can be mentioned, for example. Specific examples of these catalysts include acids such as hydrochloric acid, sulfuric acid, nitric acid, formic acid, succinic acid, acetic acid, trifluoroacetic acid, trifluoromethanesulfonic acid, phosphoric acid, acidic ion exchange resins, and various Lewis acids;
Examples of alkali metal compounds include sodium hydroxide, potassium hydroxide, sodium methoxide, potassium methoxide, sodium ethoxide, potassium ethoxide and the like;
Examples of organic bases include primary and secondary organic amines such as ethylamine, diethylamine, piperazine, piperidine, pyrrolidine and pyrrole: triethylamine, tri-n-propylamine, tri-n-butylamine, pyridine, 4-dimethylaminopyridine, diaza And tertiary organic amines such as bicycloundecene: quaternary organic amines such as tetramethylammonium hydroxide; Of these, tertiary organic amines or quaternary organic amines are preferred as the organic base.
Examples of the catalyst include alkali metal compounds or organic bases, in that side reactions such as ring opening of epoxy groups can be suppressed, hydrolysis condensation rate can be increased, and storage stability is excellent. An organic base is particularly preferable.
The amount of the organic base used varies depending on the reaction conditions such as the type of organic base and temperature, and should be set as appropriate. More preferably, it is 0.05-1 times mole.

Examples of the organic solvent used in the hydrolysis / condensation reaction include hydrocarbons, ketones, esters, ethers, alcohols and the like. Specific examples thereof include hydrocarbons such as toluene and xylene; ketones such as methyl ethyl ketone, methyl isobutyl ketone, methyl n-amyl ketone, diethyl ketone, cyclohexanone and cyclopentanone; esters such as ethyl acetate. N-butyl acetate, i-amyl acetate, propylene glycol monomethyl ether acetate, 3-methoxybutyl acetate, ethyl lactate and the like; ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, tetrahydrofuran, dioxane and the like; alcohols; For example, 1-hexanol, 4-methyl-2-pentanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethyl Glycol mono -n- propyl ether, ethylene glycol monobutyl -n- butyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono -n- propyl ether and the like; may be mentioned, respectively. Of these, it is preferable to use a water-insoluble organic solvent. In addition, these organic solvents can be used individually by 1 type or in mixture of 2 or more types.
The use ratio of the organic solvent in the hydrolytic condensation reaction is preferably 10 to 10,000 parts by weight, more preferably 50 to 1,000 parts by weight with respect to 100 parts by weight of the total silane compounds used in the reaction. .

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

  A group that expresses liquid crystal alignment ability (hereinafter also referred to as “alignment group”) may be further introduced into the specific polyorganosiloxane (A) obtained by the above reaction. The introduction of the orientation group is, for example, by synthesizing a specific polyorganosiloxane (A) having an epoxy group by polymerization containing an epoxy group-containing silane compound as a monomer, and the obtained epoxy group-containing specific polyorganosiloxane (A), This can be performed by reacting a carboxylic acid having an alignment group (hereinafter also referred to as “alignment group-containing carboxylic acid”).

  Specific examples of such an orientation group-containing carboxylic acid include, for example, long chain fatty acids such as caproic acid, n-octanoic acid, n-decanoic acid, n-dodecanoic acid, n-hexadecanoic acid and stearic acid; 4-n-hexyl Benzoic acid having a long-chain alkyl group such as benzoic acid, 4-n-octylbenzoic acid, 4-n-decylbenzoic acid, 4-n-dodecylbenzoic acid, 4-n-hexadecylbenzoic acid, 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, cholestenyloxybenzoic acid, lanostannyloxybenzoic acid, cholestanyl Xyloxycarbonylbenzoic acid, cholestenyloxycarbonylbenzoic acid, lanostannyloxycarbonylbenzoic acid, succinic acid-5ξ-cholestan-3-yl, succinic acid-5ξ-cholesten-3-yl, succinic acid-5ξ-lanostane-3- Benzoic acid having a steroid skeleton such as 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 Acid, 6- (4′-cyanobiphenyl-4-yloxy) hexanoic acid, 4- (4-pentylcyclohexyl) oxide decanoic acid, 11-((4′-pentylbicyclohexyl-4-yl) oxy) dodecanoic acid, Benzoic acid having a polycyclic structure such as 11- (4- (4-pentylcyclohexyl) phenyloxy) dodecanoic acid; 6,6,6-trifluorohexanoic acid, 4- (4,4,4-trifluorobutyl) And carboxylic acids having a fluoroalkyl group such as benzoic acid; In addition, the orientation group-containing carboxylic acid can be used alone or in combination of two or more.

  In the reaction between the specific polyorganosiloxane (A) and the carboxylic acid, the orientation group-containing carboxylic acid may be used alone, or other carboxylic acid other than the carboxylic acid may be used in combination. Specific examples of such other carboxylic acids include, for example, formic acid, acetic acid, propionic acid, benzoic acid, methylbenzoic acid, acrylic acid, methacrylic acid, 2-acryloyloxyethyl-2-hydroxyethyl-phthalic acid, 2- Examples include (meth) acryloyloxyethyl hexahydrophthalic acid. In addition, the detail of reaction with specific polyorganosiloxane (A) which has an epoxy group, and orientation group containing carboxylic acid is demonstrated collectively in the following method (2).

<About 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 the epoxy group-containing alkoxysilanes in the other silane compounds in the method (1). It is done.
In synthesizing the epoxy group-containing polyorganosiloxane, the 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 the compounds exemplified as the other silane compounds in the method (1) and the specific silane compound (ms-1).

In the synthesis of the epoxy group-containing polyorganosiloxane, the use ratio of the epoxy group-containing silane compound is the silane used in the synthesis from the viewpoint of introducing a sufficient amount of the heterocyclic structure (a) and the orientation group into the side chain of the polymer. It is preferable to set it as 10 mol% or more with respect to the whole quantity of a compound, It is more preferable to set it as 20-100 mol%, It is still more preferable to set it as 40-100 mol%.
When the above-mentioned specific silane compound (ms-1) is used as the other silane compound, its use ratio may be appropriately set according to the amount of the specific carboxylic acid (mc-1) used. Preferably it is 0.3 mol% or more with respect to the whole quantity of a compound, More preferably, it is 0.5-40 mol%, More preferably, it is 1-30 mol%.
In addition, the description of the said method (1) can be applied for details, such as a catalyst used in the hydrolysis and condensation reaction of the silane compound in the method (2), a reaction solvent, and reaction conditions.

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, Carboxylic acids having a heterocyclic ring containing one nitrogen atom, such as 4-pyridin-3-ylbenzoic acid, 4-pyridin-4-ylbenzoic acid, 1- (pyridin-3-yl) cyclopropanecarboxylic acid;
4-imidazolecarboxylic acid, 1-methyl-1H-imidazole-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-benzimidazole-6-carboxylic acid, 2- Benzyl-1-methyl-1H-benzimidazole-6-carboxylic acid, 1- [4- (benzyloxy) phenyl] -1H-benzimidazole-5 Rubonic acid, 1- [4- (benzyloxy) phenyl] -2-methyl-1H-benzimidazole-5-carboxylic acid, 1-cyclohexyl-2-methyl-1H-benzimidazole-5-carboxylic acid, 1- ( 3,4-difluorophenyl) -1H-benzimidazole-5-carboxylic acid, 1,2-dimethyl-1H-benzimidazole-5-carboxylic acid, 2-ethyl-1H-benzimidazole-6-carboxylic acid, 6- Carboxylic acids having a heterocyclic ring containing two or more nitrogen atoms, such as (1H-imidazol-1-yl) nicotinic acid and 1- (3-methoxyphenyl) -2-methyl-1H-benzimidazole-5-carboxylic acid ;
And so on. Among these, a carboxylic acid having a heterocyclic ring containing two or more nitrogen atoms is preferable, and a carboxylic acid having an imidazole structure is more preferable in terms of a high effect of improving ODF unevenness and a voltage holding ratio. In addition, specific carboxylic acid (mc-1) can be used individually by said 1 type or in combination of 2 or more types.

  As 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. Also good. Examples of the other carboxylic acids include formic acid, acetic acid, propionic acid, benzoic acid, methylbenzoic acid, (meth) acrylic acid, alkyl (meth) acrylate, and the orientation group-containing carboxylic acid described in the above method (1). Etc. In addition, “(meth) acryl” in the present specification means to include acryl and methacryl.

[Reaction of epoxy group-containing polyorganosiloxane and carboxylic acid]
The reaction between 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 proportion of carboxylic acid used in the above reaction (the total amount when two or more are used) is preferably 5 mol% or more, more preferably, based on the epoxy group of the epoxy group-containing polyorganosiloxane. It is 10-90 mol%, More preferably, it is 15-80 mol%.
Moreover, it is preferable that the usage-amount of the orientation group containing carboxylic acid in method (1) and method (2) shall be 1-80 mol% with respect to the silicon atom which an epoxy-group-containing polyorganosiloxane has, 3-70 It is more preferable to set it as mol%, and it is still more preferable to set it as 5-50 mol%. The ratio of the specific carboxylic acid (mc-1) used in the method (2) is preferably 0.3 to 20 mol% with respect to the silicon atom of the epoxy group-containing polyorganosiloxane, and is preferably 0.5 to 15 It is more preferable to set it as mol%.

As the catalyst used in the reaction, for example, a compound known as a so-called curing accelerator that accelerates the reaction of an organic base or an epoxy compound can be used.
Examples of the organic base include primary and secondary organic amines such as ethylamine, diethylamine, piperazine, piperidine, pyrrolidine and pyrrole; triethylamine, tri-n-propylamine, tri-n-butylamine, pyridine, 4-dimethylaminopyridine, And tertiary organic amines such as diazabicycloundecene; quaternary organic amines such as tetramethylammonium hydroxide; and the like. Of these, tertiary organic amines or quaternary organic amines are preferred as the organic base.
Examples of the curing accelerator include tertiary amines, imidazole compounds, organic phosphorus compounds, quaternary phosphonium salts, diazabicycloalkenes, zinc octylates and other organometallic compounds, quaternary ammonium salts, boron compounds, Examples thereof include a metal halide, a high melting point dispersion type latent curing accelerator, a microcapsule type latent curing accelerator, and a thermal cationic polymerization type latent curing accelerator. Of these, quaternary ammonium salts are preferred, and specific examples thereof include tetraethylammonium bromide, tetra-n-butylammonium bromide, tetraethylammonium chloride, tetra-n-butylammonium chloride and the like.
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 with respect to 100 parts by weight of the epoxy group-containing polyorganosiloxane. The

  Examples of the organic solvent used in the reaction between the epoxy group-containing polyorganosiloxane and the carboxylic acid include hydrocarbon compounds, ether compounds, ester compounds, ketone compounds, amide compounds, and alcohol compounds. Of these, ether compounds, ester compounds, and ketone compounds are preferable from the viewpoint of solubility of raw materials and products, and ease of purification of the products. Specific examples of particularly preferred solvents include 2-butanone and 2-hexanone. , Methyl isobutyl ketone, butyl acetate and the like. The organic solvent is preferably used in such a ratio 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, It is more preferable to use it at a ratio of 5 to 50% by weight.

  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. Moreover, after completion | finish of reaction, it is preferable to wash | clean the organic-solvent layer fractionated from the reaction liquid with water. After washing with water, the organic solvent layer is dried with a suitable desiccant as required, and then the solvent is removed to obtain the desired polyorganosiloxane.

<About method (3)>
In the method (3), the description of the method (1) can be applied to the types and mixing ratios of the specific silane compound (ms-1) and other silane compounds used for the synthesis of the specific polyorganosiloxane (A). it can.
In the method (3), a solution in which dicarboxylic acid is added to alcohol in advance is prepared, and this solution and the silane compound are mixed and heated to obtain a solution containing the target polyorganosiloxane.
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. One or more selected from these Is preferably used. Particularly preferred is oxalic acid. The proportion of dicarboxylic acid used is preferably such that the amount of carboxyl groups relative to a total of 1 mol of alkoxy groups in the silane compound used in the reaction is 0.2 to 2 mol.

Examples of the alcohol used in the above 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. The ratio of the alcohol used is preferably 10 to 10,000 parts by weight, more preferably 50 to 1,000 parts by weight with respect to 100 parts by weight of the total silane compound used in the reaction.
In the case of the said reaction, it is preferable that heating temperature shall be 50-180 degreeC. The heating time can be, for example, several tens of minutes to several tens of hours.

  Thus, a reaction solution containing the specific polyorganosiloxane (A) is obtained. This reaction solution may be used for the preparation of the liquid crystal aligning agent as it is, or may be used for the preparation of the liquid crystal aligning agent after the reaction solution is concentrated or diluted as necessary. Moreover, when the specific polyorganosiloxane (A) obtained by the said reaction has an epoxy group, you may make the said orientation group containing carboxylic acid react with the said specific polyorganosiloxane (A) further. By this reaction, the specific polyorganosiloxane (A) having the orientation group can be obtained. The description of the above method (2) can be applied to the catalyst and organic solvent used for the reaction between the specific polyorganosiloxane (A) and the orientation group-containing carboxylic acid, and various conditions such as reaction temperature and reaction time.

<About 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 synthesizing the epoxy group-containing polyorganosiloxane, the 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 the compounds exemplified as the 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 kind and amount of dicarboxylic acid and alcohol used in the synthesis of the epoxy group-containing polyorganosiloxane, reaction temperature and reaction time. In addition, the description of the above method (2) should be applied to various conditions such as the type and amount of carboxylic acid to be reacted with the epoxy group-containing polyorganosiloxane, the catalyst and organic solvent used in the reaction, and the reaction temperature and reaction time. Can do.

  The specific polyorganosiloxane (A) contained in the liquid crystal aligning agent of the present invention preferably has a polystyrene-reduced weight average molecular weight of 500 to 100,000 as measured by gel permeation chromatography (GPC). It is more preferable that it is 000-30,000.

≪Other ingredients≫
The liquid crystal aligning agent of this invention may contain other components other than the said specific polyorganosiloxane (A) as needed 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 this invention is compoundable by making tetracarboxylic dianhydride and diamine react, for example.

Tetracarboxylic dianhydride Examples of tetracarboxylic dianhydrides used for the synthesis of polyamic acid include aliphatic tetracarboxylic dianhydrides, alicyclic tetracarboxylic dianhydrides, and aromatic tetracarboxylic dianhydrides. And so on. Specific examples thereof include aliphatic tetracarboxylic dianhydrides such as 1,2,3,4-butanetetracarboxylic dianhydride;
Examples of the alicyclic tetracarboxylic dianhydride include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 1,3,3a, 4, 5,9b-Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b- Hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 3-oxabicyclo [3.2.1] octane -2,4-dione-6-spiro-3 '-(tetrahydrofuran-2', 5'-dione), 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene- No 1,2-dicarboxylic acid 3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-dianhydride, 2,4,6,8-tetracarboxybicyclo [3.3.0] octane-2 : 4,6: 8-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^2,6 ] undecane-3,5,8,10-tetraone, cyclohexanetetracarboxylic dianhydride Etc .;
Examples of aromatic tetracarboxylic dianhydrides include pyromellitic dianhydride;
In addition to the above, tetracarboxylic dianhydrides described in JP 2010-97188 A can be used. In addition, the said tetracarboxylic dianhydride can be used individually by 1 type or in combination of 2 or more types.

  As tetracarboxylic dianhydride used for synthesizing polyamic acid, alicyclic tetracarboxylic dianhydride is used alone, or alicyclic tetracarboxylic dianhydride and aromatic tetracarboxylic dianhydride. It is preferable to use a mixture with a product. In the latter case, the alicyclic tetracarboxylic dianhydride is preferably contained in an amount of 20 mol% or more, more preferably 40 mol% or more, based on the total amount of tetracarboxylic dianhydride used in the synthesis. .

-Diamine As a diamine used for the synthesis | combination of a polyamic acid, an aliphatic diamine, an alicyclic diamine, an aromatic diamine, diaminoorganosiloxane etc. can be mentioned, for example. Specific examples thereof include aliphatic diamines such as metaxylylenediamine, 1,3-propanediamine, tetramethylene diamine, pentamethylene diamine, hexamethylene diamine, and the like; alicyclic diamines such as 1,4- Diaminocyclohexane, 4,4′-methylenebis (cyclohexylamine), 1,3-bis (aminomethyl) cyclohexane and the like;

（式（Ｄ−１）中、Ｘ^I及びＸ^IIは、それぞれ独立に、単結合、−Ｏ−、−ＣＯＯ−又は−ＯＣＯ−であり、Ｒ^Ｉは炭素数１〜３のアルカンジイル基であり、Ｒ^ＩＩは単結合又は炭素数１〜３のアルカンジイル基であり、ａは０又は１であり、ｂは０〜２の整数であり、ｃは１〜２０の整数であり、ｄは０又は１である。但し、ａ及びｂが同時に０になることはない。） Examples of aromatic diamines include dodecanoxydiaminobenzene, tetradecanoxydiaminobenzene, pentadecanoxydiaminobenzene, hexadecanoxydiaminobenzene, octadecanoxydiaminobenzene, and cholestanyloxy-3,5-diaminobenzene. Cholestenyloxy-3,5-diaminobenzene, cholestanyloxy-2,4-diaminobenzene, cholestenyloxy-2,4-diaminobenzene, cholestanyl 3,5-diaminobenzoate, 3,5-diaminobenzoic acid Cholestenyl, lanostane 3,5-diaminobenzoate, 3,6-bis (4-aminobenzoyloxy) cholestane, 3- (3,5-diaminobenzoyloxy) cholestane, 3,6-bis (4-aminophenoxy) cholestane 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—, and R ^I is an alkanediyl group having 1 to 3 carbon atoms. 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 not 0 at the same time.)

Oriented group-containing diamine such as a compound represented by:
p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl sulfide, 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'-diaminodiphenyl ether, 2,2-bis [4- (4 -Aminophenoxy) phenyl] propane, 9,9-bis (4-aminophenyl) fluorene, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-amino) Phenyl) hexafluoropropane, 4,4 ′-(p-phenylenediisopropylidene) bisaniline, 4,4 ′-(m-phen Nylenediisopropylidene) bisaniline, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, 2,6-diaminopyridine, 3,4-diaminopyridine, 2, 4-diaminopyrimidine, 3,6-diaminoacridine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diamino Carbazole, 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-dihydro-1,3,3-trimethyl-1H- Indene-5-amine, 1- (4-aminophenyl) -2,3-dihydro-1,3,3-trimethyl-1H-indene-6-amine, and the like;
Examples of the diaminoorganosiloxane include 1,3-bis (3-aminopropyl) -tetramethyldisiloxane; and the diamines described in JP-A 2010-97188 can be used. Diamine can be used alone or in combination of two or more.

Examples of the divalent group represented by “—X ^I — (R ^I —X ^II ) _n —” in the formula (D-1) include an alkanediyl group having 1 to 3 carbon atoms, * —O—, * —COO— or * —O—C ₂ H ₄ —O— (however, a bond marked with “*” is bonded to a diaminophenyl group) is preferred. 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, and 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 and the like. The two amino groups in the diaminophenyl group are preferably in the 2,4-position or 3,5-position with respect to other groups.

Specific examples of the compound represented by the formula (D-1) include compounds represented by the following formulas (D-1-1) to (D-1-3).

<Synthesis of polyamic acid>
The polyamic acid can be obtained by reacting the tetracarboxylic dianhydride and diamine as described above with a molecular weight modifier as necessary. The ratio of the tetracarboxylic dianhydride and the diamine used in the polyamic acid synthesis reaction is 0.2 to 2 for the tetracarboxylic dianhydride acid anhydride group to 1 equivalent of the amino group of the diamine. The ratio which becomes an equivalent is preferable, and the ratio which becomes 0.3-1.2 equivalent is more preferable.
Examples of the molecular weight modifier include acid monoanhydrides such as maleic anhydride, phthalic anhydride and itaconic anhydride, monoamine compounds such as aniline, cyclohexylamine and n-butylamine, and monoisocyanate compounds such as phenyl isocyanate and naphthyl isocyanate. Can be mentioned. The use ratio of the terminal blocking agent 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 the tetracarboxylic dianhydride and diamine to be used.

  The polyamic acid synthesis reaction is preferably carried out in an organic solvent. The reaction temperature at this time is preferably -20 ° C to 150 ° C, more preferably 0 to 100 ° C. The reaction time is preferably from 0.1 to 24 hours, more preferably from 0.5 to 12 hours.

Examples of the organic solvent used in the reaction include aprotic polar solvents, phenol solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons, hydrocarbons, and the like. Among these organic solvents, one or more selected from the group consisting of an aprotic polar solvent and a phenolic solvent (first group organic solvent), or one or more selected from the first group of organic solvents And a mixture of at least one selected from the group consisting of alcohols, ketones, esters, ethers, halogenated hydrocarbons and hydrocarbons (second-group organic solvent). In the latter case, the proportion of the second group organic solvent used is preferably 50% by weight or less, more preferably 40% by weight, based on the total amount of the first group organic solvent and the second group organic solvent. Or less, more preferably 30% by weight or less.
Particularly preferred are N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide, m-cresol, xylenol and halogen. It is preferable to use one or more selected from the group consisting of fluorinated phenols as a solvent, or to use a mixture of one or more of these and another organic solvent in the above range.
The amount of organic solvent used (a) is such that the total amount (b) of tetracarboxylic dianhydride and diamine is 0.1 to 50% by weight based on the total amount (a + b) of the reaction solution. Is preferred.

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

<Polyamic acid ester>
The polyamic acid ester in the present invention is, for example, [I] a method of synthesizing a polyamic acid obtained by the above synthesis reaction with a hydroxyl group-containing compound, a halide, an epoxy group-containing compound, or the like, [II] tetra It can be obtained by reacting a carboxylic acid diester with a diamine, [III] reacting a tetracarboxylic acid diester dihalide with 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. 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 as an epoxy group-containing compound, Examples thereof include propylene oxide.
The tetracarboxylic acid diester used in the method [II] can be obtained, for example, by ring-opening the tetracarboxylic dianhydride exemplified in the synthesis of the polyamic acid using the above alcohols. The reaction of Method [II] is preferably carried out in the presence of a suitable dehydration catalyst. Examples of the dehydration catalyst include 4- (4,6-dimethoxy-1,3,5-triazin-2-yl) -4-methylmorpholinium halide, carbonylimidazole, a phosphorus condensing agent, and the like. 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 an appropriate chlorinating agent such as thionyl chloride.
Examples of the diamine used in the method [II] and the method [III] include diamines exemplified in the synthesis of polyamic acid. The polyamic acid ester may have only an amic acid ester structure, or may be a partially esterified product in which an amic acid structure and an amic 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 ring-closing and imidizing the polyamic acid synthesized as described above.

  The polyimide may be a completely imidized product obtained by dehydrating and cyclizing all of the amic acid structure possessed by the polyamic acid that is the precursor, and only a part of the amic acid structure is dehydrated and cyclized, It may be a partially imidized product in which an imide ring structure coexists. From the viewpoint of electrical characteristics, the polyimide in the present invention preferably has an imidization ratio of 30% or more, more preferably 50 to 99%, and still more preferably 65 to 99%. This imidation ratio represents the ratio of the number of imide ring structures to the total of the number of polyimide amic acid structures and the number of imide ring structures in percentage. Here, a part of the imide ring may be an isoimide ring.

  The polyamic acid is preferably dehydrated and closed by heating the polyamic acid, or by dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydrating ring-closing catalyst to the solution, and heating the mixture as necessary. Is called. Of these, the latter method is preferred.

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

  In this way, a reaction solution containing polyimide is obtained. This reaction solution may be used for the preparation of the liquid crystal aligning agent as it is, may be used for the preparation of the liquid crystal aligning agent after removing the dehydrating agent and the dehydrating ring-closing catalyst from the reaction solution, and the liquid crystal after isolating the polyimide. You may use for preparation of an aligning agent, or you may use for preparation of a liquid crystal aligning agent, after purifying the isolated polyimide. These purification operations can be performed according to known methods.

  The polyamic acid, polyamic acid ester and polyimide obtained as described above preferably have a solution viscosity of 10 to 800 mPa · s, when this is made into a solution having a concentration of 10% by weight, and 15 to 500 mPa · s. More preferably, it has a solution viscosity of s. In addition, the solution viscosity (mPa · s) of the above polymer is based on a polymer solution having a concentration of 10% by weight prepared using a good solvent for the polymer (eg, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.). The value measured at 25 ° C. using an E-type rotational viscometer. Regarding the 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 preferably 1,000 to 200,000. Is more preferable.

  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) is 2 It is preferable to set it as weight% or more. By making it 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%.

  Other components that may be contained in the liquid crystal aligning agent of the present invention include, in addition to the polymer (P), for example, other polymers other than the polymer (P), and at least one epoxy group in the molecule. Compounds having the same (hereinafter referred to as “epoxy group-containing compounds”), functional silane compounds, and the like.

[Other polymers]
The above other polymers can be used for improving solution properties and electrical properties. Examples of such other polymers include polyorganosiloxanes not having the above heterocyclic structure (a), polyesters, polyamides, cellulose derivatives, polyacetals, polystyrene derivatives, poly (styrene-phenylmaleimide) derivatives, poly (meth) acrylates. And so on. 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, more preferably 0.1% by weight to the total amount of the polymer in the composition. 1 to 30% by weight is more preferable.

[Epoxy group-containing compound]
The epoxy group-containing compound can be used to improve the adhesion and electrical properties with the substrate surface in the liquid crystal alignment film. Here, examples of the epoxy group-containing compound include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1 , 6-hexanediol diglycidyl ether, glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, N, N, N ′, N′-tetraglycidyl-m-xylenediamine 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ′, N′-tetraglycidyl-4,4′-diaminodi Enirumetan, N, N-diglycidyl - benzylamine, N, N-diglycidyl - aminomethyl cyclohexane, N, N-diglycidyl - may be mentioned as being preferred and cyclohexylamine. In addition, as an example of the epoxy group-containing compound, an epoxy group-containing polyorganosiloxane described in International Publication No. 2009/096598 can also be used.
When these epoxy compounds are added to the liquid crystal aligning agent, the blending ratio is preferably 40 parts by weight or less, more preferably 0.1 to 30 parts by weight with respect to 100 parts by weight of the total of the polymers contained in the liquid crystal aligning agent. preferable.

[Functional silane compounds]
The functional silane compound can be used for the purpose of improving the printability of the liquid crystal aligning agent. Examples of such functional silane compounds include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl). ) -3-Aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3- Aminopropyltrimethoxysilane, N-triethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-trimethoxysilyl -3,6- Methyl azananoate, N-benzyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, glycidoxymethyltrimethoxysilane, 2-glycidoxyethyltrimethoxysilane, 3-glycid And xylpropyltrimethoxysilane.
When these functional silane compounds are added to the liquid crystal aligning agent, the blending ratio is preferably 2 parts by weight or less, more preferably 0.02 to 0.2 parts by weight, based on 100 parts by weight of the total polymer.

  In addition to the above, examples of the other components include a compound having at least one oxetanyl group in the molecule, a bismaleimide compound, and an antioxidant. The types and blending amounts of these components can be appropriately adjusted as long as the effects of the present invention are not impaired.

<Solvent>
The liquid crystal aligning agent of the present invention is prepared as a liquid composition in which the specific polyorganosiloxane (A) and other components blended as necessary are preferably dispersed or dissolved in an appropriate organic solvent. The
Examples of the solvent used include N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N, N-dimethylformamide, N, N-dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone, Ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether , Ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol Cole 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, propylene carbonate and the like. These can be used alone or in admixture of two or more.

  The solid content concentration in the liquid crystal aligning agent of the present invention (the ratio of the total weight of components other than the solvent of the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) is appropriately selected in consideration of viscosity, volatility, and the like. The range is preferably 1 to 10% by weight. That is, the liquid crystal aligning agent of the present invention is applied to the substrate surface as described later, and preferably heated to form a coating film that is a liquid crystal alignment film or a coating film that becomes a liquid crystal alignment film. When the solid content concentration is less than 1% by weight, the film thickness of the coating film is too small to obtain a good liquid crystal alignment film. On the other hand, when the solid content concentration exceeds 10% by weight, it is difficult to obtain a good liquid crystal alignment film because the film thickness is excessive, and the viscosity of the liquid crystal aligning agent increases, resulting in poor coating characteristics. Become.

  The particularly preferable range of the solid content concentration varies depending on the method used when the liquid crystal aligning agent is applied to the substrate. For example, when the spinner method is used, the solid content concentration is particularly preferably in the range of 1.5 to 4.5% by weight. In the case of the printing method, it is particularly preferable that the solid content concentration is in the range of 3 to 9% by weight, and thereby the solution viscosity is in the range of 12 to 50 mPa · s. In the case of the inkjet method, it is particularly preferable that the solid content concentration is in the range of 1 to 5% by weight, and thereby the solution viscosity is in the range of 3 to 15 mPa · s. The temperature at the time of preparing the liquid crystal aligning agent of this invention becomes like this. Preferably it is 10-50 degreeC, More preferably, it is 20-30 degreeC.

<Liquid crystal alignment film and liquid crystal display element>
The liquid crystal alignment film of the present invention is formed by the liquid crystal aligning agent prepared as described above. Moreover, the liquid crystal display element of this invention comprises 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 a TN type, STN type, IPS type, FFS type, VA type, and MVA type. A vertical alignment type liquid crystal display element such as a VA type or an MVA type is preferable.

  The liquid crystal display element of the present invention can be produced, for example, by a method including the following steps (1) to (3). In step (1), the substrate to be used varies depending on the desired drive mode. Step (2) and step (3) are common to each drive mode.

[Step (1): Formation of coating film]
First, the liquid crystal aligning agent of this invention is apply | coated on a board | substrate, Then, a coating film is formed on a board | substrate by heating an application surface.
(1-1) When manufacturing a TN-type, STN-type, VA-type, or MVA-type liquid crystal display element, a pair of two substrates each provided with a patterned transparent conductive film is used as a transparent conductive material in each substrate. On the film forming surface, 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 ink jet printing method, respectively. Here, as the substrate, for example, glass such as float glass or soda glass; a transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, poly (cycloaliphatic olefin) can be used. As a transparent conductive film provided on one surface of the substrate, an NESA film (registered trademark of PPG, USA) made of tin oxide (SnO ₂ ), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ), etc. Can be used. In order 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. be able to. In applying the liquid crystal aligning agent, in order to further improve the adhesion between the substrate surface and the transparent conductive film and the coating film, a functional silane compound or a functional titanium compound is formed on the surface of the substrate surface on which the coating film is formed. It is also possible to perform a pretreatment to apply the above in advance.

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

  (1-2) When manufacturing an IPS type or FFS type liquid crystal display element, an electrode forming surface of a substrate provided with an electrode made of a transparent conductive film or a metal film patterned in a comb shape, and an electrode are provided. The liquid crystal aligning agent of this invention is each apply | coated to one surface of the counter substrate which is not, and then a coating film is formed by heating each application surface. Regarding the material used for the substrate and the transparent conductive film, the coating method, the heating conditions after coating, the patterning method for the transparent conductive film or the metal film, the pretreatment of the substrate, and the preferred film thickness of the coating film to be formed The same as (1-1). As the metal film, for example, a film made of a metal such as chromium can be used.

  In both cases (1-1) and (1-2), after applying a liquid crystal aligning agent on the substrate, a coating film to be an alignment film is formed by removing the organic solvent. At this time, when 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 an amic acid structure, It is good also as a more imidized coating film by advancing the dehydration ring-closing reaction by further heating after the coating film formation.

[Step (2): rubbing treatment]
When manufacturing a TN-type, STN-type, IPS-type, or FFS-type liquid crystal display element, the coating film formed in the above step (1) is fixed by a roll wound with a cloth made of fibers such as nylon, rayon, and cotton. A rubbing process that rubs in the direction is performed. Thereby, the orientation ability of a liquid crystal molecule is provided to a coating film, and it becomes a liquid crystal aligning film. On the other hand, when manufacturing a vertical alignment type liquid crystal display element, the coating film formed in the step (1) can be used as it is as a liquid crystal alignment film, but the coating film may be subjected to a rubbing treatment. In addition, for the liquid crystal alignment film after the rubbing treatment, a process for changing the pretilt angle of a part of the liquid crystal alignment film by irradiating a part of the liquid crystal alignment film with ultraviolet rays, After forming a resist film in part and performing a rubbing process in a direction different from the previous rubbing process, a process for removing the resist film is performed so that the liquid crystal alignment film has different liquid crystal alignment capabilities for each region. Good. In this case, it is possible to improve the visibility 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 liquid crystal cell]
(3-1) A liquid crystal cell is manufactured by preparing two substrates on which a liquid crystal alignment film is formed as described above and disposing a liquid crystal between the two substrates facing each other. In order to manufacture the liquid crystal cell, for example, a vacuum injection method and an ODF method can be mentioned. In the vacuum injection method, first, two substrates are arranged to face each other through a gap (cell gap) so that the respective liquid crystal alignment films are opposed to each other, and the peripheral portions of the two substrates are bonded together using a sealant. A liquid crystal cell is manufactured by injecting and filling liquid crystal into the cell gap defined by the surface and the sealing agent, and then sealing the injection hole. Further, in the ODF method, for example, an ultraviolet light curable sealant is applied to a predetermined location on one of the two substrates on which the liquid crystal alignment film is formed, and a predetermined surface on the liquid crystal alignment film surface is applied. After the liquid crystal is dropped at several places, the other substrate is bonded so that the liquid crystal alignment film faces. A liquid crystal cell is manufactured by spreading the liquid crystal over the entire surface of the substrate and then irradiating the entire surface of the substrate with ultraviolet light to cure the sealant. Regardless of which method is used, the liquid crystal cell manufactured as described above is further heated to a temperature at which the liquid crystal used takes an isotropic phase, and then slowly cooled to room temperature, thereby removing the flow alignment at the time of filling the liquid crystal. It is desirable to do.

  As the sealing agent, for example, an epoxy resin containing a curing agent and aluminum oxide spheres as a spacer can be used. Examples of the liquid crystal include nematic liquid crystals and smectic liquid crystals. Among them, nematic liquid crystals are preferable. For example, Schiff base liquid crystals, azoxy liquid crystals, biphenyl liquid crystals, phenyl cyclohexane liquid crystals, ester liquid crystals, terphenyl liquid crystals. Biphenylcyclohexane liquid crystal, pyrimidine liquid crystal, dioxane liquid crystal, bicyclooctane liquid crystal, cubane liquid crystal, and the like can be used. Further, cholesteric liquid crystals such as cholestyl chloride, cholesteryl nonate, and cholesteryl carbonate; chiral agents such as those sold under the trade names “C-15” and “CB-15” (manufactured by Merck & Co., Inc.). A ferroelectric liquid crystal such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate may be added and used.

  And the liquid crystal display element of this invention can be obtained by bonding a polarizing plate on the outer surface of a liquid crystal cell. As a polarizing plate to be bonded to the outer surface of the liquid crystal cell, a polarizing film or an H film itself in which a polarizing film called an “H film” in which iodine is absorbed while stretching and aligning polyvinyl alcohol is sandwiched between cellulose acetate protective films The polarizing plate which consists of can be mentioned. When the rubbing treatment is performed on the coating film, the two substrates are arranged to face each other so that the rubbing directions in each coating film are at a predetermined angle, for example, orthogonal or antiparallel.

  The liquid crystal display element of the present invention can be effectively applied to various devices, such as watches, portable games, word processors, notebook computers, car navigation systems, camcorders, PDAs, digital cameras, mobile phones, smartphones, The present invention can be used for various display devices such as various monitors, liquid crystal televisions, and information displays.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to 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 polyimide in each of the following synthesis examples were measured by the following methods.
[Measurement of weight average molecular weight of polymer]
The weight average molecular weight (Mw) of a polymer is a polystyrene conversion value measured by GPC having the following specifications.
Column: Tosoh, TSKgelGRCXLII
Solvent: Tetrahydrofuran Temperature: 40 ° C
Pressure: 68 kgf / cm ²
[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 for a solution prepared to a polymer concentration of 10% by weight using a predetermined solvent.
[Imidation rate of polyimide]
The polyimide solution was poured into pure water, and the resulting 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. From the obtained ¹ H-NMR spectrum, the imidation ratio [%] was determined by the formula represented by the following formula (1).
Imidation ratio [%] = (1-A ¹ / A ² × α) × 100 (1)
(In Formula (1), A ¹ is a peak area derived from protons of NH groups appearing near a chemical shift of 10 ppm, A ² is a peak area derived from other protons, and α is a precursor of a polymer (polyamic acid). The number ratio of other protons to one proton of NH group in)

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

[Synthesis Examples S-2 to S-21]
Using the alkoxysilane compounds in the amounts and ratios shown in Table 1 below, the epoxy group-containing polyorganosiloxanes (S-2) to (S-21) are viscous by performing the same operation as in Synthesis Example S-1. Each was obtained as a clear liquid. The obtained epoxy group-containing polyorganosiloxanes (S-2) to (S-21) were similarly subjected to ¹ H-NMR analysis, and confirmed that side reactions of epoxy groups did not occur during the reaction. The weight average molecular weights (Mw) of the epoxy group-containing polyorganosiloxanes (S-2) to (S-21) are also shown in Table 1.

  The numerical value of the compounding ratio in Table 1 indicates the use ratio (mol%) of each compound with respect to the total amount of monomers used for the synthesis of the epoxy group-containing polyorganosiloxane. Abbreviations of the compounds are 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) ureidopropyltri Ethoxysilane 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) methylamino Propyltrimethoxysilane ms-1-8: N- (2-methyl-1H-imidazol-1-yl) methylaminopropyltrimethoxysilane s-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

<Reaction of epoxy group-containing polyorganosiloxane and carboxylic acid>
[Synthesis Example A-1]
In a 100 mL three-necked flask, 56.0 g of the epoxy group-containing polyorganosiloxane (S-1) obtained in Synthesis Example S-1 above, 206.0 g of methyl isobutyl ketone, 1.8 g of 4-imidazolecarboxylic acid, 4-octyl 22.2 g of oxybenzoic acid and 0.6 g of UCAT 18X (a quaternary amine salt manufactured by San Apro) were charged and 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. This solution was washed with water three times, and then 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]
By using the epoxy group-containing polyorganosiloxane and the carboxylic acid in the amounts and ratios shown in Table 2 and Table 3 below, the same operations as in Synthesis Example S-1 are performed, so that polyorganosiloxane (A-2) to (A -85) was obtained as a white powder. The weight average molecular weights (Mw) of the polyorganosiloxanes (A-2) to (A-85) are shown together in Tables 2 and 3.

  In Tables 2 and 3, the numerical value of the mixing ratio of carboxylic acid indicates the amount charged (mol%) relative to the total amount of silicon atoms in the precursor polyorganosiloxane used in the reaction. Abbreviations of the compounds are as shown below.

[Specific carboxylic acid]
mc-1-1: nicotinic acid mc-1-2: 1- (pyridin-3-yl) cyclopropanecarboxylic acid mc-1-3: 4-imidazolecarboxylic acid mc-1-4: 4- (1H-imidazole) -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) oxide Decanoic 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 by performing the same operations as in Synthesis Example S-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 weights (Mw) of the polyorganosiloxanes (Ao-86) to (Ao-93) are also shown in Table 4. In addition, about the numerical value of the compounding ratio of carboxylic acid in Table 4, and the abbreviation of a compound, it is the same as the said Table 2 and Table 3.

<Synthesis of polyimide>
[Synthesis Example P-1]
2,3,5-tricarboxycyclopentylacetic acid dianhydride 189.8 g (0.85 mol) as tetracarboxylic dianhydride, p-phenylenediamine 74.7 g (0.69 mol) and cholestanyloxy as diamine compounds -5.5-g (0.17 mol) of 2,4-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 taken, NMP was added, and the viscosity was measured with a solution having a solid content concentration of 10%. The result 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, and dehydration ring closure was performed at 110 ° C. for 4 hours. After the imidization reaction, the solvent in the system was replaced with new NMP (the pyridine and acetic anhydride used in the imidization reaction were removed from the system in this operation), and a polyimide (P A solution containing about 15% by weight of -1) was obtained. A small amount of the obtained polyimide solution was collected, 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]
(I) Preparation of liquid crystal aligning agent The polyorganosiloxane (A-1) obtained in Synthesis Example A-1 is dissolved in butyl cellosolve (BC) to prepare a polysiloxane solution A-1 having a solid content concentration of 15.0%. did. Then, the solution containing the polyimide (P-1) obtained in Synthesis Example P-1 and the polysiloxane solution A-1 were changed to polyimide (P-1): polyorganosiloxane (A-1) = 95: 5 (weight ratio) was mixed, and N-methyl-2-pyrrolidone (NMP) and BC were added thereto and stirred sufficiently. To this solution, 3 parts by weight of N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane is added with respect to a total of 100 parts by weight of the polymer, and the solvent composition is NMP: BC = 60. : 40 (weight ratio) and a solid content concentration of 3.5% by weight. A liquid crystal aligning agent was prepared by filtering this solution using a filter having a pore diameter of 0.2 μm.

(2) Evaluation of liquid crystal spreading property The liquid crystal aligning agent prepared in the above (1) was used for a glass substrate with a transparent electrode having an ITO full-surface electrode structure using a liquid crystal alignment film printer (Nissha Printing Co., Ltd.). After applying to the transparent electrode surface and heating (pre-baking) on a hot plate at 80 ° C. for 1 minute to remove the solvent, heating (post-baking) on a hot plate at 200 ° C. for 10 minutes to obtain an average film thickness of 800 mm A coating film was formed. To this substrate, 7.0 μl of liquid crystal MLC-2038 (manufactured by Merck) was dropped, and the substrate-liquid crystal contact angle when left for 30 seconds was measured by the θ / 2 method using DROPMASTER 700 manufactured by Kyowa Interface Chemical Co., Ltd. . When the contact angle at this time was less than 15 degrees, the liquid crystal spreadability was “good”. When the contact angle was 15 degrees or more, the liquid crystal spreadability was “bad”. The value is shown.

(3) Manufacture of liquid crystal cell Using the liquid crystal aligning agent prepared in the above (1), a glass substrate with a transparent electrode having a fine slit ITO electrode structure using a liquid crystal alignment film printer (manufactured by Nissha Printing Co., Ltd.), And it apply | coats to the transparent electrode surface of the glass substrate with a transparent electrode which has a pattern ITO electrode structure, respectively, after heating for 1 minute on a 80 degreeC hotplate (prebaking) and removing a solvent, it is 10 degrees on a 200 degreeC hotplate. Heating for a minute (post-baking) formed a coating film having an average film thickness of 800 mm. Each substrate after the coating was formed was subjected to ultrasonic cleaning in ultrapure water for 1 minute, and then dried in a clean oven at 100 ° C. for 10 minutes. As a result, a pair (two) of substrates having a liquid crystal alignment 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 the coating film forming substrate having a fine slit ITO electrode structure, a required amount of liquid crystal MLC-6608 was dropped. . At this time, the liquid crystal was dropped at a plurality of locations on the coating film forming substrate. The total amount of liquid crystal dropped is 0.98 to 1.0 times the volume obtained by multiplying the area where the adhesive is applied and the spacer diameter, and the amount dropped at one point is 0.2 to 1.0 g. Adjusted between. Next, the substrate on which the liquid crystal was dropped was placed in a vacuum laminating apparatus, and a coating film forming substrate having a pattern ITO electrode structure was placed on the opposite side of the substrate, and then laminating was performed under vacuum. After the bonding was completed, the adhesive portion was cured using 365 nm UV light, and then annealed in an oven at 120 ° C. for 1 hour to produce a liquid crystal cell.

(4) Evaluation of Vertical Alignment After the liquid crystal cell produced as described above is placed between two polarizing plates arranged in an orthogonal state, the liquid crystal alignment state in the state of no voltage application and the AC voltage of 60 Hz are set to 0-10. The liquid crystal alignment state when applied in the range of 0.0 V (peak-peak) was observed. Orientation is `` good '' when black display is obtained without defects, etc. when no voltage is applied, and there is no bright spot or alignment disorder when voltage is applied, and when bright spots or unevenness are observed when no voltage is applied When the orientation “defective B” and a failure or alignment disorder were observed in the voltage application state were evaluated as the orientation “defective W”, the vertical alignment of the liquid crystal cell was “good”.

(5) Evaluation of voltage holding ratio After a voltage of 5 V is applied to the liquid crystal cell manufactured in (3) above with a 60 microsecond application time and a 1670 millisecond span, the voltage holding ratio after 1670 milliseconds from the release of application. Was measured. The measuring device used was a 6517-type liquid crystal property measuring device manufactured by Toyo Corporation. As a result, the voltage holding ratio was a good value of 99%.
(6) Evaluation of ODF unevenness suppression effect A 60 Hz AC voltage was applied to the liquid crystal cell manufactured in (3) above, and unevenness generated in the entire liquid crystal cell was observed. "Good" when no unevenness occurs, "bad" when unevenness occurs at the liquid crystal dropping position, and "bad (with lattice unevenness)" when unevenness occurs in the middle of the liquid crystal dropping position "When the unevenness occurred at both the liquid crystal dropping position and the liquid crystal dropping position was evaluated as" bad (with dripping marks and lattice unevenness) ", the ODF unevenness evaluation of this liquid crystal cell was" good ". It was.

[Examples 2 to 85]
The kind and amount of polyorganosiloxane to be used and the amount of polyimide (P-1) used are as shown in Table 5 and Table 6 below, and N, N, N ′, N′-tetraglycidyl-4,4 A liquid crystal aligning agent was prepared and evaluated in the same manner as in Example 1 except that '-diaminodiphenylmethane was not blended. The results are shown in Tables 5 and 6. In addition, the numerical value of the compounding ratio of a polyimide and polyorganosiloxane shows the compounding ratio (part by weight) of each polymer with respect to 100 parts by weight of the whole polymer component in the liquid crystal aligning agent.

[Comparative Examples 1-15]
A liquid crystal aligning agent was prepared and evaluated in the same manner as in Example 1 except that the type and amount of polyorganosiloxane used and the amount of polyimide (P-1) used were as shown in Table 7 below. The results are shown in Tables 5 and 6. The results are summarized in Table 7. In Table 7, “−” in the evaluation result of the ODF unevenness indicates that alignment failure occurred at the time of non-driving and the ODF unevenness could not be evaluated.

As shown in Tables 5 and 6, in the liquid crystal aligning agent (Examples 1 to 85) containing the polyorganosiloxane having a nitrogen-containing heterocyclic structure, liquid crystal spreading property, vertical alignment property, voltage holding ratio, and ODF unevenness. All of the inhibitory effects showed good results. On the other hand, in the liquid crystal aligning agent (Comparative Examples 1-15) which does not mix | blend the polyorganosiloxane which has a nitrogen-containing heterocyclic structure, as shown in Table 7, liquid crystal spreading property, vertical alignment property, and ODF nonuniformity suppression. One of the effects was bad. Moreover, about Comparative Examples 2-15, the voltage holding rate was as low as 95% or less.
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 blending a polyorganosiloxane having a nitrogen-containing heterocyclic structure. As a result, the thermosetting property of the film is improved, and the resistance to the stress on the film surface generated during the dropping of the liquid crystal and the bonding process is increased.

Claims (7)

Containing a polyorganosiloxane having a heterocyclic structure (a) containing a nitrogen atom in the ring skeleton ;
Liquid crystal aligning agent wherein the heterocyclic structure (a) is characterized by aromatic heterocyclic structure der Rukoto. Containing a polyorganosiloxane having a heterocyclic structure (a) containing a nitrogen atom in the ring skeleton ;
The heterocyclic structure (a) is a liquid crystal aligning agent characterized by chromatic two or more nitrogen atoms in the ring skeleton. The liquid crystal aligning agent of Claim 1 in which the said heterocyclic structure (a) has two or more nitrogen atoms in ring skeleton.   The liquid crystal aligning agent as described in any one of Claims 1-3 whose said heterocyclic structure (a) is an imidazole structure. The liquid crystal aligning agent as described in any one of Claims 1-4 which further contains at least 1 type of polymer chosen from the group which consists of a polyamic acid, a polyimide, and a polyamic acid ester.   The liquid crystal aligning film formed using the liquid crystal aligning agent as described in any one of Claims 1-5.   A liquid crystal display device comprising the liquid crystal alignment film according to claim 6.