Liquid crystal aligning agent

Abstract

The invention provides a liquid crystal aligning agent. The liquid crystal aligning agent contains a polymer component and at least one specific solvent selected from a group consisting of tetrahydro-4H-pyran-4-one, tetramethylene sulfoxide, a compound represented by a formula (1), a compound represented by a formula (2), a compound represented by a formula (3) and a compound represented by a formula (10). According to the invention, the liquid crystal aligning agent which is not easy to swell a printing plate and has good printability can be obtained. # imgabs0 #

Description

[0001] This is a divisional application of a divisional application with an application date of March 14, 2016, a divisional filing date of May 17, 2023, an application number of 202310555381.9, and an invention title of "Liquid Crystal Alignment Agent, Liquid Crystal Alignment Film, and Liquid Crystal Element". Technical Field

[0002] The present invention relates to a liquid crystal alignment agent, a liquid crystal alignment film, and a liquid crystal element. Background Art

[0003] In the past, various driving methods such as electrode structures or physical properties of liquid crystal molecules used have been developed for liquid crystal elements. For example, various liquid crystal elements such as twisted nematic (TN) type, super twisted nematic (STN) type, vertical alignment (VA) type, in-plane switching (IPS) type, fringe field switching (FFS) type, and optically compensated bend (OCB) type are known. These liquid crystal elements have a liquid crystal alignment film for aligning liquid crystal molecules. In terms of having good various properties such as heat resistance, mechanical strength, and affinity with liquid crystal, materials such as polyamic acid or polyimide are used for the liquid crystal alignment film.

[0004] Regarding the liquid crystal alignment agent, a polymer component is dissolved in a solvent, and the liquid crystal alignment agent is coated on a substrate and heated to form a liquid crystal alignment film. Here, as the solvent of the liquid crystal alignment agent, an aprotic polar solvent with high solubility for the polymer is usually used, such as N-methyl-2-pyrrolidone or γ-butyrolactone. In addition, in order to improve the coatability (printability) of the liquid crystal alignment agent when coating the liquid crystal alignment agent on the substrate, an aprotic polar solvent and an organic solvent with a relatively low surface tension such as butyl cellosolve are used together (for example, refer to Patent Document 1 or Patent Document 2).

[0005] As a method of coating the liquid crystal alignment agent on the substrate, various methods such as spin coating method, offset printing method, and inkjet method are applied. For example, the offset printing method is usually performed using the following transfer printing device, which coats the liquid crystal alignment agent on a printing plate containing a resin such as APR (registered trademark) and transfers the liquid crystal alignment agent to the substrate using the printing plate (for example, refer to Patent Document 3).

[0006] [Prior Art Documents]

[0007] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Laid-Open Publication No. 2010-97188

[0009] [Patent Document 2] Japanese Patent Laid-Open Publication No. 2010-156934

[0010] [Patent Document 3] Japanese Patent Laid-Open Publication No. 2001-343649 Summary of the Invention

[0011] [Problems to be Solved by the Invention]

[0012] Butyl cellosolve, which is commonly used for the purpose of improving the coatability of a liquid crystal aligning agent, has a tendency to easily swell the APR resin. Therefore, when a liquid crystal aligning agent containing butyl cellosolve is coated on a substrate by offset printing, there is a concern that the printing plate swells and the printability deteriorates due to repeated coating on the printing plate. In addition, as a solvent component of the liquid crystal aligning agent, it is required that the polymer does not easily precipitate onto the printing machine even during continuous printing, so that the printability (continuous printability) is good.

[0013] The present invention has been made in view of the above problems, and one of its objects is to provide a liquid crystal aligning agent that does not easily swell the printing plate and has good printability.

[0014] [Means for Solving the Problems]

[0015] The inventors of the present invention actively studied to solve the problems of the prior art as described above, and as a result, found that the above problems can be solved by using a specific organic solvent as a solvent, and thus completed the present invention. Specifically, the present invention provides the following liquid crystal aligning agent, liquid crystal alignment film, and liquid crystal element.

[0016] One aspect of the present invention is to provide a liquid crystal aligning agent containing a polymer component and at least one specific solvent selected from the group consisting of tetrahydro-4H-pyran-4-one, tetramethylene sulfoxide, the compound represented by the following formula (1), the compound represented by the following formula (2), the compound represented by the following formula (3), and the compound represented by the following formula (10).

[0017] [Chemical Formula 1]

[0018]

[0019] (In formula (1), R 4 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; in formula (2), R 5 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R 6 is an alkanediyl group having 2 to 4 carbon atoms; in formula (3), R 7 to R 10Each is independently a hydrogen atom or a monovalent organic group; in formula (10), R 11 ~R 13 Each is independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms)

[0020] By using the specific solvent as a solvent component of the liquid crystal aligning agent, a liquid crystal aligning agent in which a printing plate is not easily swollen can be obtained. Further, even when printing is continuously performed, the polymer is not easily deposited on the printing machine, and good printability can be achieved.

[0021] Another aspect of the present invention is to provide a liquid crystal alignment film formed from the liquid crystal aligning agent. Still another aspect is to provide a liquid crystal element including the liquid crystal alignment film formed from the liquid crystal aligning agent.

[0022] The liquid crystal alignment film of the present invention is formed by using a liquid crystal aligning agent containing the specific solvent, and thus a uniform coating film can be formed and the film quality is good. Further, when manufacturing a liquid crystal element using the liquid crystal aligning agent, printing defects can be reduced in the manufacturing process, and as a result, the yield of the product can be improved. Detailed Description

[0023] Hereinafter, each component contained in the liquid crystal aligning agent of the present invention and other components optionally blended as needed will be described.

[0024] <Polymer Component>

[0025] The liquid crystal aligning agent of the present invention contains a polymer component. The main skeleton of the polymer is not particularly limited, and examples thereof include: polyamic acid, polyamic acid ester, polyimide, polyorganosiloxane, polyester, polyamide, polybenzoxazole precursor, polybenzoxazole, cellulose derivative, polyacetal, polystyrene derivative, poly(styrene-phenyl maleimide) derivative, poly(meth)acrylate, etc. main skeletons. In addition, (meth)acrylate means acrylate and methacrylate.

[0026] In terms of the high improvement effect of the specific solvent on printability, among the polymers, the polymer component of the liquid crystal aligning agent is preferably at least one selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, and polyorganosiloxane. In addition, when preparing the liquid crystal aligning agent, the polymer can be used alone or in combination of two or more.

[0027] [Polyamic Acid]

[0028] The polyamic acid in the present invention can be obtained, for example, by reacting a tetracarboxylic dianhydride with a diamine.

[0029] (Tetracarboxylic Dianhydride)

[0030] Examples of the tetracarboxylic dianhydrides used for the synthesis of polyamic acid include, for example, aliphatic tetracarboxylic dianhydrides, alicyclic tetracarboxylic dianhydrides, aromatic tetracarboxylic dianhydrides, etc. Specific examples of these tetracarboxylic dianhydrides include, for example, 1,2,3,4-butanetetracarboxylic dianhydride, etc.;

[0031] Examples of the alicyclic tetracarboxylic dianhydrides include: 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic 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-dianhydride, bicyclo[3.3.0]octane-2,4,6,8-tetracarboxylic 2:4,6:8-dianhydride, 4,9-dioxatricyclo[5.3.1.0 2,6 undecane-3,5,8,10-tetraone, cyclohexanetetracarboxylic dianhydride, etc.;

[0032] Examples of the aromatic tetracarboxylic dianhydrides include pyromellitic dianhydride, etc.; In addition to these, the tetracarboxylic dianhydrides described in Japanese Patent Application Laid-Open No. 2010-97188 can also be used. Further, the tetracarboxylic dianhydrides can be used alone or in combination of two or more.

[0033] In terms of aspects with good electrical properties and aspects that can further improve the solubility of the polymer in a solvent containing a specific solvent and can further improve the printing property improvement effect, the tetracarboxylic dianhydride used in the synthesis preferably contains an alicyclic tetracarboxylic dianhydride. In addition, among the alicyclic tetracarboxylic dianhydrides, it preferably contains at least one selected from the group consisting of 2,3,5-tricarboxycyclopentylacetic 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, bicyclo[3.3.0]octane-2,4,6,8-tetracarboxylic 2:4,6:8-dianhydride, and 1,2,3,4-cyclobutanetetracarboxylic dianhydride, and particularly preferably contains at least one selected from the group consisting of 2,3,5-tricarboxycyclopentylacetic dianhydride, bicyclo[3.3.0]octane-2,4,6,8-tetracarboxylic 2:4,6:8-dianhydride, and 1,2,3,4-cyclobutanetetracarboxylic dianhydride.

[0034] When at least one selected from the group consisting of 2,3,5-tricarboxycyclopentylacetic dianhydride, bicyclo[3.3.0]octane-2,4,6,8-tetracarboxylic 2:4,6:8-dianhydride, and 1,2,3,4-cyclobutanetetracarboxylic dianhydride is used as the tetracarboxylic dianhydride, the total content of these compounds is preferably 10 mol% or more, more preferably 20 mol% to 100 mol%, based on the total amount of the tetracarboxylic dianhydride used in the synthesis of the polyamic acid.

[0035] (Diamine)

[0036] Examples of the diamine used in the synthesis of the polyamic acid include aliphatic diamines, alicyclic diamines, aromatic diamines, diaminoorganosiloxanes, etc. Specific examples of these diamines include, for example, aliphatic diamines such as m-xylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 1,3-bis(aminomethyl)cyclohexane, etc.; alicyclic diamines such as 1,4-diaminocyclohexane, 4,4'-methylenebis(cyclohexylamine), etc.

[0037] Aromatic diamines include, for example: p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfide, 1,5-diaminonaphthalene, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 4,4'-diaminodiphenyl ether, 1,3-bis(4-aminophenoxy)propane, 9,9-bis(4-aminophenyl)fluorene, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 4,4'-(p-phenylenediisopropylidene)dianiline, 1,4-bis(4-aminophenoxy)benzene, 2,6-diaminopyridine, 3,6-diaminocarbazole, N,N'-bis(4-aminophenyl)-benzidine, 1,4-bis-(4-aminophenyl)-piperazine, 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, 3,5-diaminobenzoic acid, cholesteryloxy-3,5-diaminobenzene, cholestenyloxy-3,5-diaminobenzene, cholesteryloxy-2,4-diaminobenzene, cholesteryl 3,5-diaminobenzoate, cholestenyl 3,5-diaminobenzoate, lanosterol 3,5-diaminobenzoate, 3,6-bis(4-aminobenzoyloxy)cholestane, 4-(4'-trifluoromethoxybenzoyloxy)cyclohexyl 3,5-diaminobenzoate, 1,1-bis(4-((aminophenyl)methyl)phenyl)-4-heptylcyclohexane, 1,1-bis(4-((aminophenyl)methyl)phenyl)-4-(4-heptylcyclohexyl)cyclohexane, 2,4-diamino-N,N-diallylaniline, 4-aminobenzylamine, N-[4-(2-aminoethyl)phenyl]benzene-1,4-diamine, N-[4-(aminomethyl)phenyl]benzene-1,4-diamine, diamines having a cinnamic acid structure, and the following formula (D-1)

[0038] [Chemical formula 2]

[0039]

[0040] (In formula (D-1), X I and X II are each independently a single bond, -O-, *-COO-, *-OCO-, or *-NH-CO- (wherein the bonding bond with "*" is bonded to the diaminophenyl group), R I and R II are each independently an alkanediyl group having 1 to 3 carbon atoms, a is 0 or 1, b is an integer of 0 to 2, c is an integer of 1 to 20, n is 0 or 1, m is 0 or 1; wherein, a and b are not both 0, and when X I is *-NH-CO-, n is 0)

[0041] Compounds etc. represented thereby;

[0042] Examples of the diaminoorganosiloxane include 1,3-bis(3-aminopropyl)-tetramethyldisiloxane etc.; in addition to these, the diamines described in Japanese Patent Laid-Open No. 2010-97188 can also be used. Further, these diamines can be used individually by one kind or in combination of two or more kinds.

[0043] Specific examples of the compound represented by the formula (D-1) include compounds represented by the following formula (D-1-1) to formula (D-1-4) etc.

[0044] [Chemical formula 3]

[0045]

[0046] The diamine for the synthesis of polyamic acid preferably contains 30 mol% or more of aromatic diamine relative to all diamines, more preferably contains 50 mol% or more, and particularly preferably contains 80 mol% or more.

[0047] (Synthesis of polyamic acid)

[0048] Polyamic acid can be obtained by reacting the tetracarboxylic dianhydride and diamine as described above, if necessary, together with a molecular weight regulator. The use ratio of the tetracarboxylic dianhydride and diamine provided for the synthesis reaction of polyamic acid is preferably such that, relative to 1 equivalent of the amino group of the diamine, the acid anhydride group of the tetracarboxylic dianhydride becomes a ratio of 0.2 equivalent to 2 equivalents. Examples of the molecular weight regulator include acid monoanhydrides such as maleic anhydride, phthalic anhydride, and itaconic anhydride; monoamine compounds such as aniline, cyclohexylamine, and n-butylamine; and mono-isocyanate compounds such as phenyl isocyanate and naphthyl isocyanate. Relative to 100 parts by weight in total of the tetracarboxylic dianhydride and diamine used, the use ratio of the molecular weight regulator is preferably set to 20 parts by weight or less.

[0049] The synthesis reaction of polyamic acid is preferably carried out in an organic solvent. The reaction temperature at this time is preferably -20°C to 150°C, and the reaction time is preferably 0.1 hour to 24 hours.

[0050] Examples of the organic solvents used in the reaction include aprotic polar solvents, phenolic solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons, hydrocarbons, etc. Particularly preferred organic solvents are preferably one or more selected from the group consisting of N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphoric triamide, m-cresol, xylenol, halogenated phenols, and specific solvents shown below as solvents, or a mixture of one or more of these solvents and other organic solvents (such as butyl cellosolve, diethylene glycol diethyl ether, etc.). The usage amount (a) of the organic solvent is preferably set such that the total amount (b) of the tetracarboxylic dianhydride and diamine is 0.1% by weight to 50% by weight with respect to the total amount (a + b) of the reaction solution.

[0051] A reaction solution in which polyamic acid is dissolved is obtained in the manner described above. The reaction solution can be directly provided for the preparation of a liquid crystal aligning agent, or the polyamic acid contained in the reaction solution can be separated and then provided for the preparation of a liquid crystal aligning agent.

[0052] [Polyimide]

[0053] The polyimide in the present invention can be obtained, for example, by dehydrating and cyclizing the polyamic acid synthesized in the above manner to imidize it. The polyimide can be a completely imidized product in which all of the amic acid structures of the polyamic acid as its precursor are dehydrated and cyclized, or a partially imidized product in which only a part of the amic acid structure is dehydrated and cyclized to coexist the amic acid structure and the imide ring structure. The imidization rate of the polyimide in the present invention is preferably 30% or more, more preferably 40% to 99%, and still more preferably 50% to 99%. The imidization rate represents the proportion of the number of imide ring structures in percentage with respect to the total of the number of amic acid structures and the number of imide ring structures of the polyimide. Here, a part of the imide ring can also be an isoimide ring.

[0054] The dehydration and cyclization of the polyamic acid is preferably carried out by the following methods: a method of heating the polyamic acid; or a method of dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydration and cyclization catalyst to the solution, and heating as required. Among them, the latter method is preferred.

[0055] In the method of adding a dehydrating agent and a dehydrating ring-closing catalyst to a solution of polyamic acid, as the dehydrating agent, acid anhydrides such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride can be used, for example. The amount of the dehydrating agent used is preferably set to be 0.01 mol to 20 mol relative to 1 mol of the amic acid structure of the polyamic acid. As the dehydrating ring-closing catalyst, tertiary amines such as pyridine, collidine, lutidine, and triethylamine can be used, for example. The amount of the dehydrating ring-closing catalyst used is preferably set to be 0.01 mol to 10 mol relative to 1 mol of the dehydrating agent used. The organic solvent used for the dehydrating ring-closing reaction can be the organic solvents exemplified as the organic solvents for the synthesis of polyamic acid. The reaction temperature of the dehydrating ring-closing reaction is preferably 0°C to 180°C, and the reaction time is preferably 1.0 hour to 120 hours.

[0056] A reaction solution containing polyimide is obtained in the above-described manner. The reaction solution can be directly provided for the preparation of a liquid crystal aligning agent, or the dehydrating agent and the dehydrating ring-closing catalyst can be removed from the reaction solution and then provided for the preparation of the liquid crystal aligning agent, or the polyimide can be separated and then provided for the preparation of the liquid crystal aligning agent. These purification operations can be carried out according to existing methods. In addition, polyimide can also be obtained by imidization of polyamic acid ester.

[0057] [Polyamic acid ester]

[0058] The polyamic acid ester in the present invention can be obtained, for example, by the following methods: [I] a method of reacting the polyamic acid obtained by the above synthesis reaction with an esterifying agent (such as methanol or ethanol, N,N-dimethylformamide diethyl acetal, etc.); [II] a method of reacting a tetracarboxylic acid diester with a diamine in an organic solvent in the presence of a suitable dehydrating catalyst (such as 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium halide, a phosphorus-based condensing agent, etc.); [III] a method of reacting a tetracarboxylic acid diester dihalide with a diamine in an organic solvent in the presence of a suitable base (such as pyridine, triethylamine, sodium hydroxide, etc.), and the like.

[0059] The polyamic acid ester contained in the liquid crystal aligning agent may have only an amic acid ester structure, or may be a partial esterified product in which an amic acid structure and an amic acid ester structure coexist. In addition, the reaction solution obtained by dissolving the polyamic acid ester can be directly provided for the preparation of the liquid crystal aligning agent, or the polyamic acid ester contained in the reaction solution can be separated and then provided for the preparation of the liquid crystal aligning agent.

[0060] The polyamic acid, polyamic acid ester and polyimide obtained in the above-described manner preferably have a solution viscosity of 10 mPa·s to 800 mPa·s when made into a 10 wt% solution, and more preferably have a solution viscosity of 15 mPa·s to 500 mPa·s. In addition, the solution viscosity (mPa·s) of the polymer is a value measured at 25 °C using an E-type rotational viscometer for a 10 wt% polymer solution prepared using a good solvent for the polymer (such as γ-butyrolactone, N-methyl-2-pyrrolidone, etc.).

[0061] Regarding the polyamic acid, polyamic acid ester and polyimide contained in the liquid crystal aligning agent of the present invention, the polystyrene-reduced weight average molecular weight measured by gel permeation chromatography (GPC) is preferably 500 to 100,000, and more preferably 1,000 to 50,000.

[0062] [Polyorganosiloxane]

[0063] The polyorganosiloxane in the present invention can be obtained, for example, by hydrolyzing or hydrolyzing and condensing a hydrolyzable silane compound preferably in the presence of a suitable organic solvent, water and a catalyst.

[0064] Examples of the hydrolyzable silane compounds used in the synthesis of polyorganosiloxanes include: alkoxysilane compounds such as tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, trimethoxysilylpropyl succinic anhydride, dimethyldimethoxysilane, and dimethyldiethoxysilane; nitrogen- and sulfur-containing alkoxysilane compounds such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, mercaptomethyltrimethoxysilane, mercaptomethyltriethoxysilane, 3-ureidopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and N-(3-cyclohexylamino)propyltrimethoxysilane; epoxy group-containing silane compounds such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; unsaturated bond-containing alkoxysilane compounds such as 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 3-(meth)acryloxypropylmethyldiethoxysilane, vinyltrimethoxysilane, and p-styryltrimethoxysilane. These hydrolyzable silane compounds can be used alone or in combination of two or more. In addition, "(meth)acryloxy" means including "acryloxy" and "methacryloxy".

[0065] The hydrolysis and condensation reaction is carried out by reacting one or more of the silane compounds as described above with water, preferably in the presence of a suitable catalyst and an organic solvent. During the reaction, the usage ratio of water is preferably 1 mole to 30 moles relative to 1 mole of the silane compound (total amount). Examples of the catalysts used include acids, alkali metal compounds, organic bases (such as triethylamine or tetramethylammonium hydroxide), titanium compounds, zirconium compounds, etc. The usage amount of the catalyst varies depending on the type of catalyst, reaction conditions such as temperature, etc., and should be set appropriately. For example, relative to the total amount of the silane compound, it is preferably 0.01-fold mole to 3-fold moles. Examples of the organic solvents used include hydrocarbons, ketones, esters, ethers, alcohols, etc. Among these organic solvents, it is preferable to use a water-insoluble or poorly water-soluble organic solvent. The usage ratio of the organic solvent is preferably 50 parts by weight to 1,000 parts by weight relative to 100 parts by weight in total of the silane compounds used in the reaction.

[0066] The hydrolysis and condensation reaction is preferably carried out by heating, for example, using an oil bath or the like. At this time, the heating temperature is preferably set to 130°C or lower, and the heating time is preferably set to 0.5 hour to 12 hours. After the reaction is completed, polyorganosiloxane can be obtained by removing the solvent from the organic solvent layer separated from the reaction solution.

[0067] When applied to a liquid crystal aligning agent for a TN-type, STN-type, or vertically aligned liquid crystal display element, a specific group such as a liquid crystal aligning group or a group having a photo-aligning structure can be introduced into the side chain of the polyorganosiloxane. The method for synthesizing a polyorganosiloxane having these specific groups in the side chain is not particularly limited. For example, the following methods can be cited: a method of hydrolytically condensing an epoxy group-containing silane compound or a mixture of an epoxy group-containing silane compound and other silane compounds to synthesize a polyorganosiloxane having an epoxy group, and then reacting the obtained epoxy group-containing polyorganosiloxane with a carboxylic acid having the specific group. The reaction between the epoxy group-containing polyorganosiloxane and the carboxylic acid can be carried out according to an existing method.

[0068] The weight average molecular weight (Mw) in terms of polystyrene measured by GPC of the polyorganosiloxane is preferably in the range of 500 to 100,000, more preferably in the range of 1,000 to 30,000, and even more preferably 1,000 to 20,000. If the weight average molecular weight of the polyorganosiloxane is within the above range, it is easy to operate in the manufacture of a liquid crystal alignment film, and the obtained liquid crystal alignment film has sufficient material strength and properties.

[0069] In the liquid crystal aligning agent of the present invention, the content ratio (in the case of containing two or more, the total amount) of the polymer selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, and polyorganosiloxane is preferably 50% by weight or more, more preferably 60% by weight or more, relative to the total amount of the polymer components in the liquid crystal aligning agent. In addition, from the viewpoint of more preferably obtaining the effects of the present invention, the polymer component preferably contains at least one selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide. The total content ratio of polyamic acid, polyamic acid ester, and polyimide in the liquid crystal aligning agent is preferably 40% by weight or more, more preferably 60% by weight or more, relative to the total amount of the polymer components in the liquid crystal aligning agent.

[0070] <Solvent>

[0071] The liquid crystal aligning agent of the present invention is a liquid composition in which a polymer component is dispersed or dissolved in a solvent. The liquid crystal aligning agent contains at least one specific solvent selected from the group consisting of a solvent having a phosphorus atom (hereinafter also referred to as "phosphorus-containing solvent"), N,N-dimethylpropyleneurea, tetrahydro-4H-pyran-4-one, tetramethylene sulfoxide, 3-methylcyclohexanone, 4-methylcyclohexanone, the compound represented by the formula (1), the compound represented by the formula (2), the compound represented by the formula (3), and the compound represented by the formula (10) as the solvent.

[0072] [Phosphorus-containing solvent]

[0073] The phosphorus-containing solvent is not particularly limited as long as it is a compound having at least one phosphorus atom in the molecule, and preferably at least one selected from the group consisting of the compounds represented by the following formulas (P-1) to (P-4) respectively.

[0074] [Chemical formula 4]

[0075]

[0076] (In the formulas (p-1) to (p-4), X 1 and Y 1 are each independently an oxygen atom or a sulfur atom; R 1 is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, and R 2 is a hydrogen atom or a monovalent organic group; wherein, R 1 and R 2 may be bonded to each other to form a ring; R 3 are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and two Rs 3 bonded to the nitrogen atom may be bonded to each other to form a monovalent nitrogen-containing heterocyclic group together with the nitrogen atom; wherein, R 1 and R 2 are not both hydrogen atoms at the same time, and R 2 and R 3 are not both hydrogen atoms at the same time; m, n, k, and j are each independently an integer of 1 to 3; when m, n, k, and j are 2 or 3, the multiple Rs 1 , R 3 in the formula may be the same or different from each other, and when m, n, k, and j are 1, the multiple Rs 2 in the formula may be the same or different from each other)

[0077] Here, in this specification, the term "hydrocarbyl group" means a group including a linear hydrocarbyl group, an alicyclic hydrocarbyl group, and an aromatic hydrocarbyl group. The "linear hydrocarbyl group" means a straight-chain hydrocarbyl group and a branched hydrocarbyl group that do not contain a cyclic structure in the main chain but are composed only of a linear structure. Among them, it can be saturated or unsaturated. The "alicyclic hydrocarbyl group" means a hydrocarbyl group that contains only an alicyclic hydrocarbon structure as the ring structure and does not contain an aromatic ring structure. Among them, it does not have to be composed only of an alicyclic hydrocarbon structure, and also includes a hydrocarbyl group having a linear structure in a part thereof. The "aromatic hydrocarbyl group" means a hydrocarbyl group that contains an aromatic ring structure as the ring structure. Among them, it does not have to be composed only of an aromatic ring structure, and may also contain a linear structure or an alicyclic hydrocarbon structure in a part thereof. In addition, in this specification, the term "organic group" means a group containing a carbon atom, and may also contain a heteroatom in the structure.

[0078] In the formula (p-1), R 1 Examples of the monovalent hydrocarbyl group having 1 to 10 carbon atoms include: linear or branched alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, and decyl; alkenyl groups such as vinyl and allyl; alkynyl groups such as ethynyl; cycloalkyl groups such as cyclopentyl, cyclohexyl, and methylcyclohexyl; aryl groups such as phenyl, tolyl, and xylyl; aralkyl groups such as benzyl, phenethyl, and styryl. Among these groups, R 1 Preferably, it is an alkyl group having 1 to 3 carbon atoms.

[0079] R 2 Examples of the monovalent organic group of R include: a monovalent hydrocarbyl group having 1 to 10 carbon atoms, a group containing a heteroatom-containing group between carbon-carbon bonds in the hydrocarbyl group, a group formed by bonding the hydrocarbyl group and a heteroatom-containing group, a group in which at least one hydrogen atom of these groups is substituted by a substituent, a cyano group, a formyl group, and the like.

[0080] Here, the heteroatom-containing group means a divalent or higher group having a heteroatom. Examples thereof include: -O-, -CO-, -COO-, -CONR a -(R a is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, the same hereinafter), -NR a -, a trivalent nitrogen atom, -NR a CONR a -, -OCONR a -, -S-, -COS-, -OCOO-, -SO2-, and the like. Examples of the substituent include: a halogen atom, a nitro group, a cyano group, a hydroxyl group, and the like. Among these groups, R 2 Preferably, it is an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 or 7 carbon atoms.

[0081] R 3 The alkyl group having 1 to 6 carbon atoms of R can be linear or branched. Two Rs3 Examples of the monovalent nitrogen-containing heterocyclic group formed by mutual bonding include the group obtained by removing the hydrogen atom bonded to the nitrogen atom of the nitrogen-containing heterocycle. Specific examples of the nitrogen-containing heterocycle include a pyridine ring, a piperidine ring, etc., and these ring moieties may have substituents such as a halogen atom, an alkyl group, etc. R 3 is preferably an alkyl group having 1 to 3 carbon atoms, more preferably a methyl group. X 1 and Y 1 is preferably an oxygen atom. m, n, k, and j are preferably 2 or 3, more preferably 3.

[0082] Regarding the aspect of a higher improvement effect on printability, in the formulas (p-1) to (p-4), the phosphorus-containing solvent is preferably at least one selected from the group consisting of the compound represented by the formula (p-1) and the compound represented by the formula (p-3), and more preferably the compound represented by the formula (p-1).

[0083] Preferred specific examples of the phosphorus-containing solvent include compounds represented by the following formulas (p-1-1) to (p-1-7), formula (p-3-1), and formula (p-3-2), respectively.

[0084] [Chemical formula 5]

[0085]

[0086] Regarding the aspect of better printability, among the compounds, the phosphorus-containing solvent is particularly preferably the compounds represented by the formulas (p-1-1) to (p-1-4) and formula (p-3-1), respectively. In addition, the phosphorus-containing solvent may be used alone or in combination of two or more.

[0087] [The compound represented by the formula (1)]

[0088] In the formula (1), R 4 The alkyl group having 1 to 6 carbon atoms includes, for example, methyl, ethyl, propyl, butyl, etc., and these alkyl groups may be linear or branched. Specific examples of the compound represented by the formula (1) include 4-formylmorpholine, 4-acetylmorpholine, etc., and 4-formylmorpholine is particularly preferred. In addition, the compound represented by the formula (1) may be used alone or in combination of two or more.

[0089] [The compound represented by the formula (2)]

[0090] In the formula (2), R 5 The illustration of the alkyl group having 1 to 6 carbon atoms can apply the description of R 4 in the formula (1). R 6Examples of the alkanediyl group having 2 to 4 carbon atoms include an ethylene group, a propanediyl group, and a butanediyl group, and these alkanediyl groups may be linear or branched. Specific examples of the compound represented by the formula (2) include 3-methyl-2-oxazolidinone, 3-ethyl-2-oxazolidinone, 3-isopropyl-2-oxazolidinone, N-methyl-2-oxazinanone, etc., and among them, 3-methyl-2-oxazolidinone is particularly preferred. In addition, the compound represented by the formula (2) may be used alone or in combination of two or more.

[0091] [The compound represented by the formula (3)]

[0092] In the formula (3), R 7 ~R 10 Examples of the monovalent organic group include an alkyl group having 1 to 10 carbon atoms, a group containing a heteroatom-containing group between the carbon-carbon bonds of the alkyl group, a group formed by bonding the alkyl group and a heteroatom-containing group, and a group in which at least one hydrogen atom of these groups is substituted with a substituent. For specific examples of the heteroatom-containing group and the substituent, the description of R 2 in the formula (p-1) can be applied. In addition, R 7 ~R 10 may be the same or different from each other. R 7 ~R 10 are preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or -COR b (R b is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms). One of R 7 and R 10 is preferably -COR b .

[0093] Specific examples of the compound represented by the formula (3) include 2-furaldehyde, 3-furaldehyde, 5-methyl-2-furaldehyde, 5-methyl-3-furaldehyde, 4-methyl-2-furaldehyde, 5-hydroxymethyl-2-furaldehyde, etc., and among them, 5-methyl-2-furaldehyde is particularly preferred. In addition, the compound represented by the formula (3) may be used alone or in combination of two or more.

[0094] [The compound represented by the formula (10)]

[0095] In the formula (10), R 11 ~R 13Examples of the alkyl group having 1 to 3 carbon atoms include methyl, ethyl, n-propyl, and isopropyl, among which methyl is preferred. Specific examples of the compound represented by the formula (10) include lactamide, N,N-dimethyl lactamide, N,N-diethyl lactamide, N-methyl-N-propyl lactamide, N-ethyl lactamide, N-isopropyl lactamide, etc., and N,N-dimethyl lactamide is particularly preferred. In addition, the compound represented by the formula (10) can be used alone or in combination of two or more.

[0096] In terms of better printability (especially continuous printability), among the compounds, as a specific solvent, at least one selected from the group consisting of a phosphorus-containing solvent, N,N-dimethylpropyleneurea, the compound represented by the formula (1), and the compound represented by the formula (2) is preferred. In addition, the specific solvent can be used alone or in combination of two or more.

[0097] [Other solvents]

[0098] The liquid crystal aligning agent of the present invention may also contain a solvent other than the specific solvent (hereinafter, also referred to as "other solvents"). Specific examples of other solvents include: N-ethyl-2-pyrrolidone, N-(n-propyl)-2-pyrrolidone, N-isopropyl-2-pyrrolidone, N-(n-butyl)-2-pyrrolidone, N-(tert-butyl)-2-pyrrolidone, N-(n-pentyl)-2-pyrrolidone, N-methoxypropyl-2-pyrrolidone, N-ethoxyethyl-2-pyrrolidone, N-methoxybutyl-2-pyrrolidone, 3-butoxy-N,N-dimethylpropanamide, 3-methoxy-N,N-dimethylpropanamide, 3-hexyloxy-N,N-dimethylpropanamide, isopropoxy-N-isopropyl-propionamide, n-butoxy-N-isopropyl-propionamide, 1,3-dimethyl-2-imidazolidinone, N,N'-dimethylpropyleneurea, tetramethylurea, N-methyl-2-pyrrolidone, γ-butyrolactone, δ-valerolactone, γ-valerolactone, γ-caprolactone, N,N-diethylacetamide, γ-butyrolactam, N,N-dimethylformamide, N,N-dimethylacetamide, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-isopropyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol monoethyl ether acetate, 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, isopentyl propionate, isopentyl isobutyrate, ethylene carbonate, propylene carbonate, etc. In addition, other solvents can be used alone or in combination of two or more.

[0099] Regarding a specific solvent, all the solvents contained in the liquid crystal aligning agent may be set as the specific solvent, or a part thereof may be set as the specific solvent. The content ratio of the specific solvent (in the case of using two or more kinds, it is the total amount thereof, the same hereinafter) relative to the total amount of the solvents contained in the liquid crystal aligning agent is preferably 1% by weight to 80% by weight, more preferably 5% by weight to 70% by weight, still more preferably 10% by weight to 60% by weight, and particularly preferably 20% by weight to 60% by weight.

[0100] <Other components>

[0101] The liquid crystal aligning agent of the present invention contains a polymer component and a solvent as described above, and may also contain other components as needed. Examples of the other components include: a compound having at least one epoxy group in the molecule, a functional silane compound, a photopolymerizable compound, a surfactant, a filler, an antifoaming agent, a sensitizer, a dispersant, an antioxidant, an adhesion aid, an antistatic agent, a leveling agent, an antibacterial agent, etc. The blending ratio of these components can be appropriately set according to the compound to be blended within the range that does not hinder the effects of the present invention.

[0102] The solid content concentration in the liquid crystal aligning agent of the present invention (the proportion of the total weight of the components other than the solvent of the liquid crystal aligning agent in the total weight of the liquid crystal aligning agent) is appropriately selected in consideration of viscosity, volatility, etc., and is preferably in the range of 1% by weight to 10% by weight. That is, the liquid crystal aligning agent of the present invention is coated on the substrate surface in the following manner, and preferably heated to form a coating film as a liquid crystal alignment film or a coating film that becomes a liquid crystal alignment film. However, at this time, when the solid content concentration is less than 1% by weight, the film thickness of the coating film becomes too small and it becomes difficult to obtain a good liquid crystal alignment film. On the other hand, when the solid content concentration exceeds 10% by weight, the film thickness of the coating film becomes too large and it is difficult to obtain a good liquid crystal alignment film, and there is a tendency that the viscosity of the liquid crystal aligning agent increases and the coating characteristics are reduced.

[0103] The particularly preferred range of the solid content concentration varies depending on the method used when coating the liquid crystal aligning agent on the substrate. For example, in the case of using the spin coating method, the solid content concentration is particularly preferably in the range of 1.5% by weight to 4.5% by weight. In the case of using the offset printing method, the solid content concentration is particularly preferably set in the range of 3% by weight to 9% by weight, and thereby the solution viscosity is set in the range of 12 mPa·s to 50 mPa·s. In the case of using the inkjet method, the solid content concentration is particularly preferably set in the range of 1% by weight to 5% by weight, and thereby the solution viscosity is set in the range of 3 mPa·s to 15 mPa·s. The temperature during the preparation of the liquid crystal aligning agent is preferably 10°C to 50°C, more preferably 20°C to 30°C.

[0104] <Liquid Crystal Alignment Film and Liquid Crystal Element>

[0105] The liquid crystal alignment film of the present invention is formed from a liquid crystal aligning agent prepared in the manner described above. In addition, the liquid crystal element of the present invention includes a liquid crystal alignment film formed using the liquid crystal aligning agent. The driving mode of the liquid crystal in the liquid crystal element is not particularly limited, and it can be applied to various driving modes such as TN type, STN type, IPS type, FFS type, VA type, multi-domain vertical alignment (MVA) type, polymer sustained alignment (PSA) type, etc. The liquid crystal element of the present invention can be manufactured, for example, by a method including the following steps 1 to 3. Regarding step 1, the substrates used vary depending on the desired driving mode. Steps 2 and 3 are common to each driving mode.

[0106] [Step 1: Formation of a Coating Film]

[0107] First, the liquid crystal aligning agent of the present invention is coated on a substrate, and then the coated surface is heated to form a coating film on the substrate.

[0108] (1-1) In the case of manufacturing a liquid crystal element of TN type, STN type, VA type, MVA type or PSA type, two substrates provided with patterned transparent conductive films are set as a pair, and on the formation surfaces of the transparent conductive films in each substrate, the liquid crystal aligning agent is respectively coated preferably by offset printing method, spin coating method, roll coating method or inkjet printing method. Substrates can be used, for example: glass such as float glass, soda glass, etc.; transparent substrates containing plastics such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, poly(alicyclic olefin), etc. The transparent conductive film provided on one of the surfaces of the substrate can be a NESA film (registered trademark of PPG Industries, Inc., USA) containing tin oxide (SnO2), an indium tin oxide (ITO) film containing indium oxide - tin oxide (IN2O3 - SnO2), etc.

[0109] After applying the liquid crystal aligning agent, in order to prevent dripping of the applied aligning agent or the like, it is preferable to perform preliminary heating (pre-baking). The pre-baking temperature is preferably 30°C to 200°C, and the pre-baking time is preferably 0.25 minutes to 10 minutes. Thereafter, in order to completely remove the solvent and, additionally as needed, to thermally imidize the amic acid structure present in the polymer, a calcination (post-baking) step is performed. The calcination temperature (post-baking temperature) at this time is preferably 80°C to 300°C, and the post-baking time is preferably 5 minutes to 200 minutes. The film thickness of the film formed in the above manner is preferably 0.001 μm to 1 μm, more preferably 0.005 μm to 0.5 μm.

[0110] (1-2) In the case of manufacturing an IPS type or FFS type liquid crystal display element, a liquid crystal aligning agent is applied to the electrode forming surface of a substrate provided with an electrode including a transparent conductive film or a metal film patterned in a comb shape and to one surface of a counter substrate not provided with an electrode, and then each coated surface is heated to form a coating film. Regarding the materials of the substrate and the transparent conductive film used at this time, the coating method, the heating conditions after coating, the film thickness, etc., they are the same as those in the above (1-1). As the metal film, for example, a film containing a metal such as chromium can be used.

[0111] In any of the above (1-1) and (1-2) cases, a liquid crystal alignment film or a coating film that becomes a liquid crystal alignment film is formed by removing the organic solvent after applying the liquid crystal aligning agent on the substrate.

[0112] [Step 2: Alignment ability imparting treatment]

[0113] In the case of manufacturing a TN type, STN type, IPS type or FFS type liquid crystal display element, a treatment for imparting liquid crystal alignment ability to the coating film formed in Step 1 is performed. Thus, the alignment ability of the liquid crystal molecules is imparted to the coating film to become a liquid crystal alignment film. Examples of the alignment ability imparting treatment include: a rubbing treatment in which a roller wound with a cloth containing fibers such as nylon, rayon, and cotton is used to wipe the coating film in a certain direction, a photo-alignment treatment in which polarized or non-polarized radiation is irradiated on the coating film, etc. On the other hand, in the case of manufacturing a VA type liquid crystal display element, the coating film formed in Step 1 can be directly used as a liquid crystal alignment film, or the alignment ability imparting treatment can be performed on the film. The preferred liquid crystal alignment film for VA type liquid crystal display elements can also be preferably used for PSA (Polymer sustained alignment) type liquid crystal display elements.

[0114] [Step 3: Construction of liquid crystal cell]

[0115] Prepare two substrates each formed with a liquid crystal alignment film in the above-described manner, and dispose liquid crystal between the two substrates arranged to face each other, thereby manufacturing a liquid crystal cell. For manufacturing a liquid crystal cell, for example, the following methods can be cited: (1) a method in which two substrates are arranged to face each other with a gap therebetween in such a manner that the liquid crystal alignment films face each other, the peripheral portions of the two substrates are bonded using a sealant, liquid crystal is injected and filled into the cell gap defined by the substrate surfaces and the sealant, and then the injection hole is sealed; (2) a method in which a sealant is applied to a predetermined position on one of the substrates formed with a liquid crystal alignment film, and then liquid crystal is dropped at several predetermined positions on the surface of the liquid crystal alignment film, and then another substrate is bonded in such a manner that the liquid crystal alignment films face each other, and the liquid crystal is spread over the entire surface of the substrate (One Drop Fill (ODF) method), etc. For the manufactured liquid crystal cell, it is ideal to further heat it to the temperature at which the liquid crystal used obtains an isotropic phase, and then slowly cool it to room temperature, thereby removing the flow alignment during liquid crystal filling.

[0116] As the sealant, for example, an epoxy resin containing a hardening agent and alumina balls as spacers can be used. Examples of the liquid crystal include nematic liquid crystal and discotic liquid crystal, and among them, nematic liquid crystal is preferred. For example, Schiff base type liquid crystal, azoxy type liquid crystal, biphenyl type liquid crystal, phenylcyclohexane type liquid crystal, ester type liquid crystal, terphenyl type liquid crystal, biphenylcyclohexane type liquid crystal, pyrimidine type liquid crystal, dioxane type liquid crystal, bicyclooctane type liquid crystal, cubane type liquid crystal, etc. can be used. In addition, cholesteric liquid crystal, chiral agent, ferroelectric liquid crystal, etc. can also be added to these liquid crystals and used.

[0117] In the case of manufacturing a PSA type liquid crystal display element, a liquid crystal cell is constructed in the same manner as described above, except for the aspect of injecting or dropping a photopolymerizable compound together with the liquid crystal. Thereafter, the liquid crystal cell is irradiated with light while a DC or AC voltage is applied between the conductive films provided on the pair of substrates. In addition, in the case of forming a coating film on the substrate using a liquid crystal aligning agent containing a photopolymerizable compound, a liquid crystal cell can also be constructed in the same manner as described above, and thereafter, a liquid crystal element is manufactured through the step of irradiating the liquid crystal cell with light while a DC or AC voltage is applied between the conductive films provided on the pair of substrates.

[0118] Moreover, the liquid crystal display element of the present invention can be obtained by bonding a polarizing plate to the outer surface of the liquid crystal cell. Examples of the polarizing plate bonded to the outer surface of the liquid crystal cell include a polarizing plate formed by sandwiching a polarizing film called an "H film" with a cellulose acetate protective film, or a polarizing plate including the "H film" itself, and the "H film" is formed by stretching and orienting polyvinyl alcohol and absorbing iodine.

[0119] The liquid crystal element of the present invention can be effectively applied to various devices, for example, it can be used in: various display devices such as clocks, portable game consoles, word processors, notebook personal computers, car navigation systems, video cameras, personal digital assistants (PDAs), digital cameras, mobile phones, smart phones, various monitors, liquid crystal TVs, etc., or dimming films, etc. In addition, the liquid crystal element formed using the liquid crystal aligning agent of the present invention can also be applied to a retardation film.

[0120] [Examples]

[0121] Hereinafter, the present invention will be further specifically described according to examples, but the present invention is not limited by these examples.

[0122] The solution viscosity of each polymer solution in the synthesis examples, the imidization rate of the polyimide, the weight average molecular weight, and the epoxy equivalent were measured by the following methods.

[0123] [Solution viscosity of polymer solution (mPa·s)] Using an E-type rotational viscometer, a solution adjusted to a polymer concentration of 10% by weight using a predetermined solvent was measured at 25°C.

[0124] [Imidization rate of polyimide] The polyimide solution was poured into pure water, and after sufficiently drying the resulting precipitate under reduced pressure at room temperature, it was dissolved in deuterated dimethyl sulfoxide, and using tetramethylsilane as a reference substance, it was measured at room temperature 1 H-nuclear magnetic resonance ( 1 H-Nuclear Magnetic Resonance, 1 H-NMR). According to the obtained 1 H-NMR spectrum, the imidization rate [%] was calculated using the following formula (1).

[0125] Imidization rate [%] = (1 - A 1 / A 2 ×α) × 100... (1)

[0126] (In formula (1), A 1 is the peak area derived from the proton of the NH group that appears around a chemical shift of 10 ppm, A 2 is the peak area derived from other protons, and α is the ratio of the number of other protons to one proton of the NH group in the precursor (polyamic acid) of the polymer)

[0127] [Weight average molecular weight Mw of polymer] is the polystyrene conversion value measured by gel permeation chromatography under the following conditions.

[0128] Column: Manufactured by Tosoh Corporation, TSKgel GRC XL II

[0129] Solvent: Tetrahydrofuran

[0130] Temperature: 40 °C

[0131] Pressure: 68 kgf / cm 2

[0132] [Epoxy equivalent] Measured by the hydrochloric acid - methyl ethyl ketone method described in Japanese Industrial Standards (JIS) C 2105.

[0133] <Synthesis of polymer>

[0134] [Synthesis Example 1: Synthesis of polyimide (PI - 1)]

[0135] Dissolve 22.4 g (0.1 mol) of 2,3,5 - tricarboxycyclopentylacetic dianhydride (TCA) as a tetracarboxylic dianhydride, 8.6 g (0.08 mol) of p - phenylenediamine (PDA) as a diamine, and 10.5 g (0.02 mol) of cholesteryl 3,5 - diamino benzoate (HCDA) in 166 g of N - methyl - 2 - pyrrolidone (NMP), and react at 60 °C for 6 hours to obtain a solution containing 20 wt% of polyamic acid. Take a small amount of the obtained polyamic acid solution, add NMP to make a solution with a polyamic acid concentration of 10 wt%, and the measured solution viscosity is 90 mPa·s.

[0136] Subsequently, add NMP to the obtained polyamic acid solution to make a solution with a polyamic acid concentration of 7 wt%, add 11.9 g of pyridine and 15.3 g of acetic anhydride, and carry out a dehydration ring - closing reaction at 110 °C for 4 hours. After the dehydration ring - closing reaction, replace the solvent in the system with fresh NMP (by this operation, the pyridine and acetic anhydride used in the dehydration ring - closing reaction are removed outside the system. The same applies hereinafter), thereby obtaining a solution containing 26 wt% of polyimide (PI - 1) with an imidization rate of about 68%. Take a small amount of the obtained polyimide solution, add NMP to make a solution with a polyimide concentration of 10 wt%, and the measured solution viscosity is 45 mPa·s. Subsequently, inject the reaction solution into excess methanol to precipitate the reaction product. Wash the precipitate with methanol and dry it at 40 °C under reduced pressure for 15 hours to obtain polyimide (PI - 1).

[0137] [Synthesis Example 2: Synthesis of polyimide (PI - 2)]

[0138] 22.5 g (0.1 mol) of TCA as a tetracarboxylic dianhydride, 7.6 g (0.07 mol) of PDA as a diamine, 5.2 g (0.01 mol) of HCDA, and 4.0 g (0.02 mol) of 4,4'-diaminodiphenylmethane (DDM) were dissolved in 157 g of NMP, and reacted at 60 °C for 6 hours to obtain a solution containing 20 wt% of polyamic acid. A small amount of the obtained polyamic acid solution was taken, NMP was added to prepare a solution with a polyamic acid concentration of 10 wt%, and the measured solution viscosity was 110 mPa·s.

[0139] Subsequently, NMP was added to the obtained polyamic acid solution to prepare a solution with a polyamic acid concentration of 7 wt%, 16.6 g of pyridine and 21.4 g of acetic anhydride were added, and a dehydration ring-closure reaction was carried out at 110 °C for 4 hours. After the dehydration ring-closure reaction, the solvent in the system was replaced with fresh NMP to obtain a solution containing 26 wt% of polyimide (PI-2) with an imidization rate of about 82%. A small amount of the obtained polyimide solution was taken, NMP was added to prepare a solution with a polyimide concentration of 10 wt%, and the measured solution viscosity was 62 mPa·s. Subsequently, the reaction solution was poured into excess methanol to precipitate the reaction product. The precipitate was washed with methanol and dried at 40 °C under reduced pressure for 15 hours to obtain polyimide (PI-2).

[0140] [Synthesis Example 3: Synthesis of Polyimide (PI-3)]

[0141] 24.9 g (0.10 mol) of bicyclo[3.3.0]octane-2,4,6,8-tetracarboxylic 2:4,6:8-dianhydride (BODA) as a tetracarboxylic dianhydride, 8.6 g (0.08 mol) of PDA as a diamine, and 10.4 g (0.02 mol) of HCDA were dissolved in 176 g of NMP, and reacted at 60 °C for 6 hours to obtain a solution containing 20 wt% of polyamic acid. A small amount of the obtained polyamic acid solution was taken, NMP was added to prepare a solution with a polyamic acid concentration of 10 wt%, and the measured solution viscosity was 103 mPa·s.

[0142] Subsequently, NMP was added to the obtained polyamic acid solution to prepare a solution with a polyamic acid concentration of 7% by weight. 11.9 g of pyridine and 15.3 g of acetic anhydride were added, and a dehydration and cyclization reaction was carried out at 110 °C for 4 hours. After the dehydration and cyclization reaction, the solvent in the system was replaced with fresh NMP, thereby obtaining a solution containing polyimide (PI-3) with an imidization rate of approximately 71% and a content of 26% by weight. A small amount of the obtained polyimide solution was taken, NMP was added to prepare a polyimide solution with a concentration of 10% by weight, and the measured solution viscosity was 57 mPa·s. Subsequently, the reaction solution was poured into excess methanol to precipitate the reaction product. The precipitate was washed with methanol and dried at 40 °C under reduced pressure for 15 hours, thereby obtaining polyimide (PI-3).

[0143] [Synthesis Example 4: Synthesis of Polyimide (PI-4)]

[0144] 110 g (0.50 mol) of TCA as a tetracarboxylic dianhydride, 160 g (0.50 mol) of 1,3,3a,4,5,9b-hexahydro-8-methyl-5-(tetrahydro-2,5-dioxo-3-furanyl)naphtho[1,2-c]furan-1,3-dione, 91 g (0.85 mol) of PDA as a diamine, 25 g (0.10 mol) of 1,3-bis(3-aminopropyl)tetramethyldisiloxane, 25 g (0.040 mol) of 3,6-bis(4-aminobenzoyloxy)cholestane, and 1.4 g (0.015 mol) of aniline as a monoamine were dissolved in 960 g of NMP, and the reaction was carried out at 60 °C for 6 hours, thereby obtaining a solution containing polyamic acid. A small amount of the obtained polyamic acid solution was taken, NMP was added to prepare a polyamic acid solution with a concentration of 10% by weight, and the measured solution viscosity was 60 mPa·s.

[0145] Subsequently, 2,700 g of NMP was added to the obtained polyamic acid solution, 390 g of pyridine and 410 g of acetic anhydride were added, and a dehydration and cyclization reaction was carried out at 110 °C for 4 hours. After the dehydration and cyclization reaction, the solvent in the system was replaced with fresh γ-butyrolactone, thereby obtaining approximately 2,500 g of a solution containing polyimide (PI-4) with an imidization rate of approximately 95% and a content of 15% by weight. A small amount of the solution was taken, NMP was added to prepare a polyimide solution with a concentration of 10% by weight, and the measured solution viscosity was 70 mPa·s. Subsequently, the reaction solution was poured into excess methanol to precipitate the reaction product. The precipitate was washed with methanol and dried at 40 °C under reduced pressure for 15 hours, thereby obtaining polyimide (PI-4).

[0146] [Synthesis Example 5: Synthesis of Polyimide (PI-5)]

[0147] 22.4 g (0.1 mol) of TCA as a tetracarboxylic dianhydride, 8.6 g (0.08 mol) of PDA as a diamine, 2.0 g (0.01 mol) of DDM, and 3.2 g (0.01 mol) of 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl were dissolved in 324 g of NMP, and reacted at 60 °C for 4 hours to obtain a solution containing 10 wt% of polyamic acid.

[0148] Subsequently, 360 g of NMP was added to the obtained polyamic acid solution, 39.5 g of pyridine and 30.6 g of acetic anhydride were added, and a dehydration cyclization reaction was carried out at 110 °C for 4 hours. After the dehydration cyclization reaction, the solvent in the system was replaced with fresh NMP to obtain a solution containing 10 wt% of polyimide (PI-5) with an imidization rate of about 93%. A small amount of the obtained polyamic acid solution was taken, and the measured solution viscosity was 30 mPa·s. Subsequently, the reaction solution was poured into excess methanol to precipitate the reaction product. The precipitate was washed with methanol and dried at 40 °C under reduced pressure for 15 hours to obtain polyimide (PI-5).

[0149] [Synthesis Example 6: Synthesis of Polyimide (PI-6)]

[0150] The diamine used was changed to 0.08 mol of 3,5-diaminobenzoic acid (3,5DAB) and 0.02 mol of cholesteryloxy-2,4-diaminobenzene (HCODA). Otherwise, a polyamic acid solution was obtained by the same method as in Synthesis Example 1. A small amount of the obtained polyamic acid solution was taken, NMP was added to make a solution with a polyamic acid concentration of 10 wt%, and the measured solution viscosity was 80 mPa·s.

[0151] Subsequently, imidization was carried out by the same method as in Synthesis Example 1 to obtain a solution containing 26 wt% of polyimide (PI-6) with an imidization rate of about 65%. A small amount of the obtained polyimide solution was taken, NMP was added to make a solution with a polyimide concentration of 10 wt%, and the measured solution viscosity was 40 mPa·s. Subsequently, the reaction solution was poured into excess methanol to precipitate the reaction product. The precipitate was washed with methanol and dried at 40 °C under reduced pressure for 15 hours to obtain polyimide (PI-6).

[0152] [Synthesis Example 7: Synthesis of Polyamic Acid (PA-1)]

[0153] 200 g (1.0 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CB) as a tetracarboxylic dianhydride and 210 g (1.0 mol) of 2,2'-dimethyl-4,4'-diaminobiphenyl as a diamine were dissolved in a mixed solvent of 370 g of NMP and 3,300 g of γ-butyrolactone, and reacted at 40 °C for 3 hours to obtain a polyamic acid solution having a solid content concentration of 10% by weight and a solution viscosity of 160 mPa·s. Subsequently, the polyamic acid solution was poured into excess methanol to precipitate the reaction product. The precipitate was washed with methanol and dried at 40 °C under reduced pressure for 15 hours to obtain polyamic acid (PA-1).

[0154] [Synthesis Example 8: Synthesis of Polyamic Acid (PA-2)]

[0155] The tetracarboxylic dianhydride used was 0.9 mol of pyromellitic dianhydride (PMDA) and 0.1 mol of CB, and the diamines were 0.2 mol of PDA and 0.8 mol of 4,4'-diaminodiphenyl ether (DDE). Otherwise, a polyamic acid solution having a solid content concentration of 10% by weight and a solution viscosity of 170 mPa·s was obtained in the same manner as in Synthesis Example 7. Subsequently, the polyamic acid solution was poured into excess methanol to precipitate the reaction product. The precipitate was washed with methanol and dried at 40 °C under reduced pressure for 15 hours to obtain polyamic acid (PA-2).

[0156] [Synthesis Example 9: Synthesis of Polyamic Acid (PA-3)]

[0157] 7.0 g (0.031 mol) of TCA as a tetracarboxylic dianhydride and 13 g of the compound represented by the following formula (R-1) (equivalent to 1 mol relative to 1 mol of TCA) as a diamine were dissolved in 80 g of NMP and reacted at 60 °C for 4 hours to obtain a solution containing 20% by weight of polyamic acid (PA-3). The solution viscosity of the polyamic acid solution was 2,000 mPa·s. In addition, the compound represented by the following formula (R-1) was synthesized according to the description in Japanese Patent Laid-Open No. 2011-100099. Subsequently, the polyamic acid solution was poured into excess methanol to precipitate the reaction product. The precipitate was washed with methanol and dried at 40 °C under reduced pressure for 15 hours to obtain polyamic acid (PA-3).

[0158] [Chemical Formula 6]

[0159]

[0160] [Synthesis Example 10: Synthesis of Polyorganosiloxane (ASP-1)]

[0161] In a reaction vessel equipped with a stirrer, a thermometer, a dropping funnel, and a reflux condenser, 100.0 g of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane (ECETS), 500 g of methyl isobutyl ketone, and 10.0 g of triethylamine were charged and mixed at room temperature. Subsequently, 100 g of deionized water was added dropwise over 30 minutes using the dropping funnel, and then the mixture was stirred under reflux at 80 °C for 6 hours. After completion of the reaction, the organic layer was taken out and washed with a 0.2 wt% ammonium nitrate aqueous solution until the washed water became neutral, and then the solvent and water were distilled off under reduced pressure to obtain a reactive polyorganosiloxane (EPS-1) in the form of a viscous transparent liquid. The reactive polyorganosiloxane (EPS-1) was subjected to 1 1H-NMR analysis. As a result, a peak based on the epoxy group with the theoretical intensity was obtained near the chemical shift (δ) = 3.2 ppm, confirming that no side reaction of the epoxy group occurred during the reaction. The weight-average molecular weight Mw of the obtained reactive polyorganosiloxane was 3,500, and the epoxy equivalent was 180 g / mol.

[0162] Subsequently, 10.0 g of the reactive polyorganosiloxane (EPS-1), 30.28 g of methyl isobutyl ketone as a solvent, 3.98 g of 4-dodecyloxybenzoic acid as a reactive compound, and 0.10 g of UCAT 18X (trade name, manufactured by San-Apro Co., Ltd.) as a catalyst were charged into a 200 mL three-necked flask and reacted with stirring at 100 °C for 48 hours. After completion of the reaction, the solution obtained by adding ethyl acetate to the reaction mixture was washed three times with water, and the organic layer was dried using magnesium sulfate, and then the solvent was distilled off to obtain 9.0 g of a liquid crystal aligning polyorganosiloxane (ASP-1). The weight-average molecular weight Mw of the obtained polymer was 9,900.

[0163] [Synthesis Example 11: Synthesis of Polyorganosiloxane (PS1)]

[0164] In a reaction vessel equipped with a stirrer, a thermometer, a dropping funnel, and a reflux condenser, 31 g of p-styryltrimethoxysilane, 70 g of tetrahydrofuran, 33 g of triethylamine, and 25 g of deionized water were added and mixed at room temperature. Subsequently, the mixture was stirred under reflux at 60 °C for 3 hours. After completion of the reaction, the organic layer was taken out, and 60 g of diethylene glycol diethyl ether was added, followed by heating and concentration. The concentration was continued until the solid content concentration became 30%, thereby obtaining a diethylene glycol diethyl ether solution of polyorganosiloxane (PS1).

[0165] [Synthesis Example 12, Synthesis Example 13]

[0166] The input raw materials were set as shown in Table 1 below. In addition, using the same synthesis method as in Synthesis Example 11, diethylene glycol diethyl ether solutions of polyorganosiloxane (PS2) and polyorganosiloxane (PS3) were obtained. The weight average molecular weight Mw of the obtained polyorganosiloxane is also shown in Table 1 below.

[0167] [Table 1]

[0168]

[0169] In addition, in Table 1, the abbreviations of the raw material silane compounds have the following meanings respectively.

[0170] STTMS: p-styryltrimethoxysilane

[0171] ECETMS: 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane

[0172] PTMS: phenyltrimethoxysilane

[0173] [Example 1]

[0174] <Preparation of Liquid Crystal Alignment Agent>

[0175] Using polyimide (PI-1) as a polymer, trimethyl phosphate (PTM), N-methyl-2-pyrrolidone (NMP), and butyl cellosolve (BC) were added thereto to prepare a solution having a solvent composition of PTM:NMP:BC = 20:40:40 (weight ratio) and a solid content concentration of 6.5% by weight. The solution was filtered using a filter with a pore size of 1 μm to prepare a liquid crystal alignment agent (S-1). In addition, the liquid crystal alignment agent (S-1) is mainly used for the manufacture of vertically aligned liquid crystal display elements.

[0176] <Evaluation of Swelling Characteristics of Printing Plate>

[0177] The swelling ease (swelling property) of the APR plate was evaluated using the liquid crystal aligning agent (S-1). The APR plate is a resin plate formed by irradiating a partially cured liquid photosensitive resin with ultraviolet light and is usually used in the printing plate of a liquid crystal alignment film printer. When the liquid crystal aligning agent is in contact with the APR plate, the fact that the APR plate is not easily swollen means that the liquid crystal aligning agent is not easily infiltrated into the APR plate during printing and the printability is good. The evaluation of the swelling property is carried out by immersing the APR plate in the liquid crystal aligning agent for 1 day and measuring the weight change of the APR plate before and after immersion. At this time, when the increase rate (swelling rate) of the weight of the APR plate is less than 4%, the APR plate is not easily swollen and is evaluated as good (○), and when the increase rate is 4% or more, the APR plate is easily swollen and is evaluated as bad (×). As a result, in the said example, the swelling rate was 3.5% and the swelling property was "good (○)". The swelling rate was calculated using the following formula (2).

[0178] Swelling rate [%] = ((W 2 -W 1 ) / W 1 ) × 100…(2)

[0179] (In formula (2), W 1 is the weight of the APR plate before immersion, and W 2 is the weight of the APR plate after immersion)

[0180] <Evaluation of printability>

[0181] Regarding the liquid crystal aligning agent (S-1) prepared above, the printability (continuous printability) in the case of continuously printing on a substrate was evaluated. The evaluation was carried out as follows. First, using a liquid crystal alignment film printer (manufactured by Nippon Shashin Printing Co., Ltd., Angstrom model "S40L-532"), under the condition that the dropping amount of the liquid crystal aligning agent (S-1) onto the anilox roll was set to 20 drops (about 0.2 g) for a round trip, it was printed on the transparent electrode surface of a glass substrate with a transparent electrode including an ITO film. Regarding the printing on the substrate, it was carried out 20 times while using a new substrate at 1-minute intervals.

[0182] Subsequently, the liquid crystal aligning agent (S-1) was dispensed (one-way) onto the anilox roll at 1-minute intervals, and at that time, a total of 10 operations of bringing the anilox roll into contact with the printing plate (hereinafter referred to as idling) were carried out (during which printing on the glass substrate was not performed). In addition, the said idling is an operation carried out to intentionally perform the printing of the liquid crystal aligning agent under severe conditions.

[0183] After 10 dry runs, glass substrates were then used for the actual printing. During the actual printing, 5 substrates were fed at 30-second intervals after the dry runs. After printing, each substrate was heated at 80 °C for 1 minute (pre-baking) to remove the solvent, and then heated at 200 °C for 10 minutes (post-baking) to form a coating film with a thickness of approximately 80 nm. The printability (continuous printability) was evaluated by observing the coating film with a microscope at a magnification of 20 times. For the evaluation, the case where no precipitation of the polymer was observed in the first actual printing after the dry runs was defined as "good (○)" for continuous printability. The case where precipitation of the polymer was observed in the first actual printing after the dry runs but became unobservable during 5 actual printings was defined as "acceptable (△)" for continuous printability. The case where precipitation of the polymer was still observed after repeating 5 actual printings was defined as "poor (×)" for continuous printability. As a result, the continuous printability in the said Example was "good (○)". In addition, it was found from the experiments that in a liquid crystal aligning agent with good printability, the precipitation of the polymer improved (disappeared) during continuous feeding of the substrates. Furthermore, the number of dry runs was changed to 15, 20, and 25 times, and the printability of the liquid crystal aligning agents was evaluated in the same manner as above. As a result, in the said Example, it was "good (○)" when the number of dry runs was 15 and 20 times, and "acceptable (△)" when it was 25 times.

[0184] [Examples 2 to 31 and Comparative Examples 1 to 5]

[0185] The types and compositions of the polymers and solvents used were changed as described in Table 2 below. Other than that, liquid crystal aligning agents (S-2) to (S-31) and liquid crystal aligning agents (SR-1) to (SR-5) were prepared respectively using the same method as in Example 1 above. In addition, for each liquid crystal aligning agent, the swelling characteristics and printability of the printing plate were evaluated in the same manner as in Example 1 above. The results of these evaluations are shown in Table 2 below.

[0186] [Table 2]

[0187]

[0188] In Table 2, for those using two polymers as the polymer components (Examples 18 to 31), the usage ratios (weight ratios) of the respective polymers relative to 100 parts by weight of the total amount of the polymers used are shown together. Among the respective liquid crystal aligning agents, (S-2) to (S-17), (SR-1) to (SR-5) are mainly used for the manufacture of vertically aligned liquid crystal display elements, (S-18) to (S-23) are mainly used for the manufacture of TN-type liquid crystal display elements, (S-24) is mainly used for the manufacture of IPS liquid crystal display elements, and (S-29) to (S-31) are mainly used for the manufacture of vertically aligned liquid crystal display elements using the photo-alignment method, and (S-25) to (S-28) are mainly used for the manufacture of liquid crystal display elements of the PSA method. In Table 2, the numerical values of the solvent composition represent the blending ratios (weight ratios) of the respective compounds relative to the total amount of the solvents used in the preparation of the liquid crystal aligning agent (the same applies to Tables 3 to 5 below). The symbols of the solvent composition have the following meanings respectively.

[0189] a: Trimethyl phosphate

[0190] b: Triethyl phosphate

[0191] c: Hexamethylphosphoric triamide

[0192] d: N-Methyl-2-pyrrolidone

[0193] e: N-Ethyl-2-pyrrolidone

[0194] f: γ-Butyrolactone

[0195] g: γ-Valerolactone

[0196] h: δ-Valerolactone

[0197] i: N,N-Diethylacetamide

[0198] j: Butyl cellosolve

[0199] k: Diethylene glycol diethyl ether

[0200] l: Propylene glycol monomethyl ether acetate

[0201] [Examples 32 to 52]

[0202] The types and compositions of the polymers and solvents used were changed as described in Table 3 below, and other than that, liquid crystal aligning agents (S-32) to (S-52) were prepared by the same method as in Example 1. In addition, for each liquid crystal aligning agent, the swelling characteristics and printability of the printing plate were evaluated in the same manner as in Example 1. The results of these evaluations are shown in Table 3 below.

[0203] [Table 3]

[0204]

[0205] In Table 3, for those using two polymers as the polymer components (Examples 40 to 43, Examples 50 to 52), the usage ratios (weight ratios) of each polymer relative to 100 parts by weight of the total amount of the polymers used are shown together. In addition, in each liquid crystal aligning agent, (S-32) to (S-39), (S-44) to (S-49) are mainly used for manufacturing vertical alignment type liquid crystal display elements, and (S-40) to (S-43), (S-50) to (S-52) are mainly used for manufacturing TN type liquid crystal display elements. In Table 3, the symbols of the solvent compositions have the following meanings respectively. d and j are the same as those in Table 2 described above.

[0206] m: N,N-dimethylpropyleneurea

[0207] n: 4-formylmorpholine

[0208] o: 3-methyl-2-oxazolidinone

[0209] p: tetrahydro-4H-pyran-4-one

[0210] r: tetramethylene sulfoxide

[0211] s: 3-methylcyclohexanone

[0212] t: 4-methylcyclohexanone

[0213] [Examples 53 to 56]

[0214] The polymer components used, as well as the types and compositions of the solvents, were changed as described in Table 4 below. Other than that, liquid crystal aligning agents (S-53) to (S-56) were respectively prepared by the same method as in Example 1 described above. In addition, for each liquid crystal aligning agent, the swelling characteristics and printability of the printing plate were evaluated in the same manner as in Example 1 described above. The results of these evaluations are shown in Table 4 below.

[0215] [Table 4]

[0216]

[0217] In Table 4, for those using two polymers as the polymer components (Example 55 and Example 56), the usage ratios (weight ratios) of each polymer relative to 100 parts by weight of the total amount of the polymers used are shown together. In addition, in each liquid crystal aligning agent, (S-53) and (S-54) are mainly used for manufacturing vertically aligned liquid crystal display elements, and (S-55) and (S-56) are mainly used for manufacturing TN-type liquid crystal display elements. In Table 4, the symbols of the solvent compositions have the following meanings respectively. d and j are the same as those in Table 2 described above.

[0218] q: 5-methyl-2-furaldehyde

[0219] u: N,N-dimethyl lactamide (compound represented by the following formula (10-1))

[0220] [Chemical Formula 7]

[0221]

[0222] [Examples 57 to 60]

[0223] The types and compositions of the polymers and solvents used were changed as described in Table 5 below. Otherwise, liquid crystal aligning agents (S-57) to (S-60) were prepared by the same method as in Example 1 above. In addition, for each liquid crystal aligning agent, the swelling characteristics and printability of the printing plate were evaluated in the same manner as in Example 1 above. The results of these evaluations are shown in Table 5 below. In addition, in Table 5, the numerical values in the polymer component column represent the usage ratios (weight ratios) of each polymer relative to 100 parts by weight of the total amount of the polymers used. The symbols (d, m, j) of the solvent compositions are the same as those in Table 2 and Table 3 above.

[0224] [Table 5]

[0225]

[0226] From the above results, it can be seen that the liquid crystal aligning agents (Examples 1 to 60) containing the specific solvent are not likely to cause swelling of the printing plate and have good continuous printability. In contrast, the swelling characteristics and continuous printability of the liquid crystal aligning agents of the comparative examples without the specific solvent are worse than those of the examples.

Claims

1. A liquid crystal aligning agent, comprising: a polymer component, and at least one specific solvent selected from the group consisting of compounds represented by the following formula (3), In formula (3), R 7 ~R 10 are each independently a hydrogen atom or a monovalent organic group, and the monovalent organic group is an alkyl group having 1 to 10 carbon atoms, a group containing a heteroatom-containing group between carbon-carbon bonds of the alkyl group, a group formed by bonding the alkyl group and a heteroatom-containing group, or a group in which at least one hydrogen atom of these groups is substituted with a substituent, and the substituent is a halogen atom, a nitro group, a cyano group, or a hydroxy group.

2. The liquid crystal aligning agent according to claim 1, wherein the polymer component contains at least one polymer selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, and polyorganosiloxane.

3. The liquid crystal aligning agent according to claim 1, wherein the content ratio of the specific solvent is 1% by weight to 80% by weight relative to the total amount of the solvents in the liquid crystal aligning agent.

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