Liquid crystal alignment agent, liquid crystal alignment film, method for producing liquid crystal alignment film, liquid crystal element, and method for producing liquid crystal element

Abstract

The present invention provides a liquid crystal alignment agent, a liquid crystal alignment film, a method for manufacturing a liquid crystal alignment film, a liquid crystal element, and a method for manufacturing a liquid crystal element. A liquid crystal alignment agent comprises (A) component, (B) component, and (C) component. (A) polymer; (B) a compound having two or more nucleophilic functional groups or acidic functional groups in one molecule, and one or more of the nucleophilic functional groups or acidic functional groups present in one molecule has a partial structure [T] formed by bonding a nitrogen atom, a sulfur atom, or an oxygen atom to a detachable group that is detached by at least one of heat and light, wherein the (A) component is excluded; (C) a compound having two or more electrophilic functional groups in one molecule, wherein the (A) component and a compound having a free radical polymerizable carbon-carbon double bond are excluded.

Description

Technical Field

[0001] The present invention relates to a liquid crystal alignment agent, a liquid crystal alignment film, a method for producing the liquid crystal alignment film, a liquid crystal element, and a method for producing the liquid crystal element. Background Art

[0002] The liquid crystal element includes a liquid crystal alignment film having the function of aligning liquid crystal molecules in a liquid crystal layer in a certain direction. Generally, the liquid crystal alignment film is formed on the substrate by applying a liquid crystal alignment agent prepared by dissolving a polymer component in an organic solvent to the substrate surface, preferably by heating.

[0003] In recent years, large-screen and high-definition liquid crystal televisions have become the mainstream, and the popularization of small display terminals such as smart phones and tablet personal computers (tablet PCs) has further increased the demand for high-quality liquid crystal elements. In view of this, in order to improve the performance of liquid crystal alignment films and make various characteristics of liquid crystal elements excellent, various liquid crystal alignment agents have been proposed (for example, see Patent Document 1). Patent Document 1 discloses that a liquid crystal alignment agent contains a polyimide or a polyimide precursor, and a compound having a structure in which a hydroxymethyl group is bonded to an aromatic ring as a crosslinking agent.

[0004] [Prior art literature]

[0005] [Patent Document]

[0006] [Patent Document 1] International Publication No. 2010 / 074269 Summary of the invention

[0007] [Problems to be solved by the invention]

[0008] The use of a crosslinking agent is an effective means for the high functionality of a liquid crystal alignment film. On the other hand, due to the high density of the film caused by the use of a crosslinking agent, when the liquid crystal alignment film is peeled off from the substrate in the manufacturing step of the liquid crystal element and the substrate is reused (reprocessed), there is a concern that it is difficult to peel off the liquid crystal alignment film from the substrate.

[0009] In addition, in the liquid crystal alignment agent necessary for forming a film, storage stability is important for ensuring the driving characteristics of the manufacturing panel. However, in the liquid crystal alignment agent using a cross-linking agent, there is a trade-off relationship between the reliability of the obtained liquid crystal alignment film and the storage stability of the liquid crystal alignment agent. If from the perspective of achieving further high quality of the liquid crystal element, as a cross-linking agent to be deployed in the liquid crystal alignment agent, a compound that is stable at a storage temperature and exhibits a high cross-linking efficiency when the film is formed is required. Furthermore, it is also pointed out that in the liquid crystal alignment agent containing a cross-linking agent, it is easy to produce a disorder of the orientation direction of the formed liquid crystal alignment film.

[0010] The present invention has been made in view of the above-mentioned problems, and a main object of the present invention is to provide a liquid crystal aligning agent which is excellent in storage stability and can form a liquid crystal aligning film having good reworkability and liquid crystal orientation.

[0011] [Technical means to solve the problem]

[0012] According to the present invention, the following means can be provided.

[0013] [1] A liquid crystal aligning agent comprising the following components (A), (B) and (C):

[0014] (A) Polymer

[0015] (B) A compound having two or more nucleophilic functional groups or acidic functional groups in one molecule, wherein one or more of the nucleophilic functional groups or acidic functional groups in one molecule has a partial structure [T] in which a nitrogen atom, a sulfur atom or an oxygen atom is bonded to a leaving group that is released by at least one of heat and light (except the component (A)).

[0016] (C) A compound having two or more electrophilic functional groups in one molecule (excluding the above-mentioned component (A) and a compound having a radically polymerizable carbon-carbon double bond.)

[0017] [2] A liquid crystal alignment film formed using the liquid crystal alignment agent according to [1].

[0018] [3] A liquid crystal element comprising the liquid crystal alignment film according to [2].

[0019] [4] A method for manufacturing a liquid crystal element, comprising: a step of applying the liquid crystal alignment agent of [1] onto each of the conductive films of a pair of substrates having a conductive film to form a coating film; a step of arranging the pair of substrates coated with the liquid crystal alignment agent so that the coating films face each other with a liquid crystal layer sandwiched therebetween to construct a liquid crystal unit; and a step of irradiating the liquid crystal unit with light while applying a voltage between the conductive films.

[0020] [Effects of the Invention]

[0021] According to the liquid crystal aligning agent of the present invention, by containing the polymer component together with the (B) component and the (C) component, the storage stability is excellent, and a liquid crystal aligning film having good reworkability and liquid crystal orientation can be formed. DETAILED DESCRIPTION

[0022] Liquid crystal alignment agent

[0023] The liquid crystal aligning agent of the present disclosure contains a polymer as the (A) component, and contains the following (B) component and (C) component as a cross-linking agent.

[0024] Component (B): a compound having two or more nucleophilic functional groups or acidic functional groups in one molecule, wherein one or more of the nucleophilic functional groups or acidic functional groups in one molecule has a partial structure [T] in which a nitrogen atom, a sulfur atom or an oxygen atom is bonded to a leaving group that is released by at least one of heat and light (except the component (A)).

[0025] Component (C): A compound having two or more electrophilic functional groups in one molecule (excluding the component (A) and compounds having a radically polymerizable carbon-carbon double bond.)

[0026] Hereinafter, each component contained in a liquid crystal aligning agent and other components arbitrarily mix|blend as needed are demonstrated.

[0027] In addition, in this specification, the so-called "hydrocarbon group" means a chain hydrocarbon group, an alicyclic hydrocarbon group and an aromatic hydrocarbon group. The so-called "chain hydrocarbon group" refers to a straight-chain hydrocarbon group and a branched hydrocarbon group that does not contain a cyclic structure in the main chain but consists only of a chain structure. Among them, it can be saturated or unsaturated. The so-called "alicyclic hydrocarbon group" refers to a hydrocarbon group that only contains the structure of alicyclic hydrocarbon as a ring structure and does not contain an aromatic ring structure. Among them, it is not necessary to be composed only of the structure of alicyclic hydrocarbons, and a hydrocarbon group having a chain structure in a part thereof is also included. The so-called "aromatic hydrocarbon group" refers to a hydrocarbon group that contains an aromatic ring structure as a ring structure. Among them, it is not necessary to be composed only of the aromatic ring structure, and a chain structure or an alicyclic hydrocarbon structure may be contained in a part thereof.

[0028] <(A) Component: polymer component>

[0029] The main skeleton of the polymer component contained in the liquid crystal alignment agent is not particularly limited. As a polymer component, for example, polyamic acid, polyamic acid ester, polyimide, polyamine, polyenamine (Polyenamine), polyorganosiloxane, polyester, polyamide, polyamide-imide, polystyrene, polybenzoxazole precursor, polybenzoxazole, cellulose derivatives, polyacetal, polymaleimide, styrene-maleimide copolymer or poly (methyl) acrylate as the main skeleton, and a polymer having a functional group that reacts (cross-linking reaction) with compound [B] and compound [C]. In addition, (methyl) acrylate refers to acrylate and methacrylate. The so-called polyenamine is a polymer having a carbon-carbon double bond at the ortho position of the amino group of polyamines, for example, polyenamine ketone, polyenamine ester, polyenamine nitrile, polyenamine sulfonyl, etc. can be listed.

[0030] As the polymer component, among the above components, in terms of obtaining a liquid crystal element with better liquid crystal orientation and electrical properties, it is preferred that at least one polymer selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, polyorganosiloxane, and a polymer having a partial structure derived from a monomer having a polymerizable unsaturated bond (hereinafter, also referred to as "polymer (Pm)"). Among the above components, in terms of high reliability of the obtained liquid crystal element, the liquid crystal aligning agent of the present disclosure is particularly preferably: as a polymer component, it includes at least one polymer selected from the group consisting of polyamic acid, polyamic acid ester and polyimide.

[0031] Next, preferred examples of the polymer contained in the liquid crystal aligning agent of the present disclosure are described.

[0032] (Polyamic acid)

[0033] The polyamic acid can be obtained by reacting tetracarboxylic dianhydride with a diamine compound.

[0034] Tetracarboxylic dianhydride

[0035] Examples of the tetracarboxylic dianhydride used in the synthesis of the polyamic acid include aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, aromatic tetracarboxylic dianhydride, etc. Specific examples of the aliphatic tetracarboxylic dianhydride include 1,2,3,4-butanetetracarboxylic dianhydride, etc.;

[0036] Examples of the alicyclic tetracarboxylic dianhydride include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 5-(2,5-dioxotetrahydrofuran-3-yl)-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 5-(2,5-dioxotetrahydrofuran-3-yl)-8-methyl-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride, cyclopentanetetracarboxylic dianhydride, and cyclohexanetetracarboxylic dianhydride.

[0037] Examples of the aromatic tetracarboxylic dianhydride include pyromellitic dianhydride, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, ethylene glycol ditriphthalic anhydride, 4,4'-carbonyl diphthalic anhydride, and the like. In addition, tetracarboxylic dianhydrides described in Japanese Patent Laid-Open No. 2010-97188 may also be used. As the tetracarboxylic dianhydride, one species may be used alone or two or more species may be used in combination.

[0038] In terms of improving the solubility of the polymer and obtaining a liquid crystal alignment film showing good electrical properties, the tetracarboxylic dianhydride used in the synthesis of the polyamic acid is preferably selected from at least one of the group consisting of aliphatic tetracarboxylic dianhydride and alicyclic tetracarboxylic dianhydride, and more preferably alicyclic tetracarboxylic dianhydride. Relative to the total amount of tetracarboxylic dianhydride used in the synthesis of the polyamic acid, the amount of alicyclic tetracarboxylic dianhydride used is preferably 20 mol% or more, more preferably 40 mol% or more, and further preferably 50 mol% or more.

[0039] ·Diamine compounds

[0040] As the diamine compound used for the synthesis of the polyamic acid, a known compound can be used. Examples of the diamine compound include aliphatic diamines, alicyclic diamines, aromatic diamines, and diaminoorganosiloxanes.

[0041] Examples of the diamine compound used in the synthesis of the polyamic acid include meta-xylylenediamine, 1,3-propylenediamine, tetramethylenediamine, pentamethylenediamine, and hexamethylenediamine; examples of the alicyclic diamine include 1,4-diaminocyclohexane and 4,4'-methylenebis(cyclohexylamine);

[0042] Examples of the aromatic diamines include p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4-aminophenyl-4-aminobenzoate, 4,4'-diaminoazobenzene, 1,5-bis(4-aminophenoxy)pentane, 1,2-bis(4-aminophenoxy)ethane, 1,6-bis(4-aminophenoxy)hexane, bis[2-(4-aminophenyl)ethyl]adipic acid, 2,6-diaminopyridine, 1,4-bis-(4-aminophenyl)-piperazine, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, Main chain diamines such as benzene, 4,4'-diaminodiphenyl ether, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis(4-aminophenyl)hexafluoropropane, 4,4'-(phenylenediisopropylidene)dianiline, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-[4,4'-propane-1,3-diylbis(piperidin-1,4-diyl)]dianiline, 4,4'-diaminobenzanilide, 4,4'-diaminostilbene, and 1,4-bis(4-aminophenyl)-piperazine;

[0043] Dodecyloxy-2,4-diaminobenzene, pentadecyloxy-2,4-diaminobenzene, hexadecyloxy-2,4-diaminobenzene, octadecyloxy-2,4-diaminobenzene, pentadecyloxy-2,5-diaminobenzene, octadecyloxy-2,5-diaminobenzene, cholesteryloxy-3,5-diaminobenzene, cholesteryloxy-3,5-diaminobenzene, cholesteryloxy-2,4-diaminobenzene, cholesteryloxy-2,4-diaminobenzene, cholesteryl 3,5-diaminobenzoate , 3,5-diaminobenzoic acid cholesteryl ester, 3,5-diaminobenzoic acid lanostanyl ester, 3,6-bis(4-aminobenzoyloxy)cholestane, 3,6-bis(4-aminophenoxy)cholestane, 4-(4'-trifluoromethoxybenzoyloxy)cyclohexyl-3,5-diaminobenzoate, 1,1-bis(4-((aminophenyl)methyl)phenyl)-4-butylcyclohexane, 3,5-diaminobenzoic acid=5ξ-cholestane-3-yl, the following formula (E-1)

[0044] [Chemistry 1]

[0045]

[0046] (In formula (E-1), X I and X II are independently a single bond, -O-, *-COO- or *-OCO- (wherein "*" indicates the I The bonding bond of R I It is an alkanediyl group having 1 to 3 carbon atoms. II is a single bond or an alkanediyl group having 1 to 3 carbon atoms.III is an alkyl group, an alkoxy group, a fluoroalkyl group or a fluoroalkoxy group having 1 to 20 carbon atoms. a is 0 or 1. b is an integer from 0 to 3. c is an integer from 0 to 2. d is 0 or 1. Wherein 1≦a+b+c≦3. ) or a side chain diamine represented by a compound;

[0047] Examples of diaminoorganosiloxane include 1,3-bis(3-aminopropyl)-tetramethyldisiloxane, and diamines described in JP-A-2010-97188 may also be used. When synthesizing polyamic acid, one diamine compound may be used alone or two or more may be used in combination.

[0048] Synthesis of polyamic acid

[0049] Polyamic acid can be obtained by reacting the tetracarboxylic dianhydride and diamine compound as described above with a molecular weight modifier as needed. The ratio of the tetracarboxylic dianhydride and diamine compound used in the synthesis reaction of polyamic acid is preferably a ratio in which the anhydride group of the tetracarboxylic dianhydride is 0.2 equivalents to 2 equivalents relative to 1 equivalent of the amino group of the diamine compound. As a molecular weight modifier, for example, acid monoanhydrides such as maleic anhydride, phthalic anhydride, and itaconic anhydride; monoamine compounds such as aniline, cyclohexylamine, and n-butylamine; monoisocyanate compounds such as phenyl isocyanate and naphthyl isocyanate, etc. The molecular weight modifier is preferably used in an amount of 20 parts by mass or less relative to a total of 100 parts by mass of the tetracarboxylic dianhydride and diamine compound used.

[0050] The synthesis reaction of the polyamic acid is preferably carried out in an organic solvent. The reaction temperature is preferably -20°C to 150°C, and the reaction time is preferably 0.1 hour to 24 hours.

[0051] As the organic solvent used in the reaction, for example, there can be mentioned: aprotic polar solvents, phenolic solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons, hydrocarbons, etc. Particularly preferred organic solvents are preferably selected from the group consisting of N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphoric triamide, metacresol, dimethyl phenol and halogenated phenol as solvents, or a mixture of one or more of them with other organic solvents (for example, butyl cellosolve, diethylene glycol diethyl ether, etc.). The amount of organic solvent used (a) is preferably set to an amount that makes the total amount (b) of tetracarboxylic dianhydride and diamine relative to the total amount (a+b) of the reaction solution 0.1 mass % to 50 mass %.

[0052] In the above manner, a reaction solution in which polyamic acid is dissolved can be obtained. The reaction solution can be directly used for the preparation of a liquid crystal aligning agent, or the polyamic acid contained in the reaction solution can be separated and then used for the preparation of a liquid crystal aligning agent.

[0053] (Polyamic acid ester)

[0054] Polyamic acid esters can be obtained, for example, by the following methods: [I] a method of reacting the polyamic acid obtained by the synthesis reaction with an esterifying agent; [II] a method of reacting a tetracarboxylic acid diester with a diamine compound; [III] a method of reacting a tetracarboxylic acid diester dihalide with a diamine compound. The polyamic acid ester contained in the liquid crystal aligning agent 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. The reaction solution formed by dissolving the polyamic acid ester may be directly used for the preparation of the liquid crystal aligning agent, or the polyamic acid ester contained in the reaction solution may be separated and then used for the preparation of the liquid crystal aligning agent.

[0055] (Polyimide)

[0056] Polyimide can be obtained, for example, by dehydrating and ring-closing the polyamic acid synthesized as described above and imidizing it. Polyimide can be a completely imidized product formed by dehydrating and ring-closing all the amic acid structures possessed by the polyamic acid as its precursor, or it can be a partially imidized product in which only a part of the amic acid structure is dehydrated and ring-closed and the amic acid structure and the imide ring structure coexist. The polyimide used in the preparation of the liquid crystal alignment agent preferably has an imidization rate of 20% to 99%, and more preferably 30% to 90%. The imidization rate is expressed as a percentage of the proportion of the number of imide ring structures relative to the total number of amic acid structures and the number of imide ring structures of the polyimide. Here, a part of the imide ring may also be an isoimide ring.

[0057] The dehydration ring-closure of polyamic acid is preferably carried out by the following method: dissolving polyamic acid in an organic solvent, adding a dehydrating agent and a dehydration ring-closure catalyst to the solution and heating as needed. In the method, as a dehydrating agent, for example, anhydrides such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride can be used. The amount of the dehydrating agent used is preferably set to 0.01 mol to 20 mol relative to 1 mol of the amic acid structure of the polyamic acid. As a dehydration ring-closure catalyst, for example, tertiary amines such as pyridine, trimethylpyridine, dimethylpyridine, and triethylamine can be used. The amount of the dehydration ring-closure catalyst used is preferably set to 0.01 mol to 10 mol relative to 1 mol of the dehydrating agent used. As an organic solvent used in the dehydration ring-closure reaction, the organic solvent exemplified as the user in the synthesis of polyamic acid can be cited. The reaction temperature of the dehydration ring-closure reaction is preferably 0°C to 180°C. The reaction time is preferably 1.0 hour to 120 hours. The reaction solution containing the polyimide obtained by the above reaction 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 isolating the polyimide. The polyimide can also be obtained by imidizing a polyamic acid ester.

[0058] Regarding the solution viscosity of the polyamic acid, polyamic acid ester and polyimide contained in the liquid crystal aligning agent, when a solution with a concentration of 10% by mass is prepared, it is preferably a solution viscosity of 10mPa·s to 800mPa·s, and more preferably a solution viscosity of 15mPa·s to 500mPa·s. In addition, the solution viscosity (mPa·s) is a value measured at 25°C using an E-type rotational viscometer for a polymer solution with a concentration of 10% by mass prepared using a good solvent for the polymer (e.g., γ-butyrolactone, N-methyl-2-pyrrolidone, etc.).

[0059] The weight average molecular weight (Mw) of polyamic acid, polyamic acid ester and polyimide measured by gel permeation chromatography (GPC) in terms of polystyrene is preferably 1,000 to 500,000, more preferably 5,000 to 100,000. The molecular weight distribution (Mw / Mn) represented by the ratio of Mw to the number average molecular weight (Mn) in terms of polystyrene measured by GPC is preferably 15 or less, more preferably 10 or less.

[0060] (Polysiloxane)

[0061] The polyorganosiloxane contained in the liquid crystal alignment agent can be obtained, for example, by hydrolyzing / condensing a hydrolyzable silane compound. Examples of hydrolyzable silane compounds include alkoxysilane compounds such as tetramethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, and dimethyldiethoxysilane; nitrogen / sulfur-containing alkoxysilane compounds such as 3-mercaptopropyltriethoxysilane, mercaptomethyltriethoxysilane, 3-aminopropyltrimethoxysilane, and N-(3-cyclohexylamino)propyltrimethoxysilane; 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, and 3-aminopropyltrimethoxysilane. Silane compounds containing epoxy groups such as 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane; alkoxysilane compounds containing unsaturated bonds such as 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 3-(meth)acryloxypropylmethyldiethoxysilane, vinyltriethoxysilane, p-phenylenetrimethoxysilane; trimethoxysilylpropylsuccinic anhydride, etc. The hydrolyzable silane compound can be used alone or in combination of two or more. In addition, "(meth)acryloxy" refers to "acryloxy" and "methacryloxy".

[0062] The hydrolysis / condensation reaction can be carried out by reacting one or more of the silane compounds described above with water, preferably in the presence of a suitable catalyst and an organic solvent. When the reaction is carried out, the proportion of water used is preferably 1 to 30 moles relative to 1 mole of the silane compound (total amount). As the catalyst used, for example, acids, alkali metal compounds, organic bases, titanium compounds, zirconium compounds, etc. can be listed. The amount of the catalyst used varies depending on the type of catalyst, reaction conditions such as temperature, etc., and should be appropriately set, for example, relative to the total amount of the silane compound, preferably 0.01 times mole to 3 times mole. As the organic solvent used, for example, hydrocarbons, ketones, esters, ethers, alcohols, etc. can be listed. Among the organic solvents, it is preferred to use a water-insoluble or poorly water-soluble organic solvent. Relative to a total of 100 parts by mass of the silane compound used in the reaction, the proportion of the organic solvent used is preferably 10 parts by mass to 10,000 parts by mass.

[0063] The hydrolysis / condensation reaction is preferably carried out by heating in an oil bath, for example. At this time, the heating temperature is preferably set to 130° C. or less, and the heating time is preferably set to 0.5 to 12 hours. After the reaction is completed, the organic solvent layer separated from the reaction solution can be dried with a desiccant as needed to remove the solvent, thereby obtaining the target polyorganosiloxane. In addition, the synthesis method of polyorganosiloxane is not limited to the hydrolysis / condensation reaction, for example, it can be carried out by a method of reacting a hydrolyzable silane compound in the presence of oxalic acid and alcohol, etc.

[0064] The polyorganosiloxane has a polystyrene-equivalent weight average molecular weight (Mw) measured by GPC that is preferably in the range of 100 to 50,000, and more preferably in the range of 200 to 10,000.

[0065] (Polymer(Pm))

[0066] As the monomer having a polymerizable unsaturated bond used in the synthesis of the polymer (Pm), for example, compounds having a (meth)acryloyl group, a vinyl group, a vinylphenyl group, a maleimide group, etc. can be cited. In addition, as the polymer (Pm), in terms of being able to form a liquid crystal alignment film having excellent liquid crystal orientation, at least one selected from the group consisting of poly (meth)acrylates, maleimide-based polymers, and styrene-maleimide-based copolymers can be preferably used.

[0067] Specific examples of the monomer having a polymerizable unsaturated bond include: unsaturated carboxylic acids such as (meth)acrylic acid, α-ethylacrylic acid, maleic acid, fumaric acid, and vinylbenzoic acid; unsaturated carboxylic acid esters such as alkyl (meth)acrylates (e.g., methyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, etc.), cycloalkyl (meth)acrylates, benzyl (meth)acrylate, trimethoxysilylpropyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, glycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, 3,4-epoxybutyl (meth)acrylate, and 4-hydroxybutyl glycidyl (meth)acrylate; unsaturated polycarboxylic acid anhydrides such as maleic anhydride; and (meth)acrylic compounds;

[0068] Aromatic vinyl compounds such as styrene, methylstyrene, divinylbenzene, and 4-(glycidyloxymethyl)styrene; conjugated diene compounds such as 1,3-butadiene and 2-methyl-1,3-butadiene;

[0069] Maleimide compounds such as N-methylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, 4-(2,5-dioxo-3-pyrrolidin-1-yl)benzoic acid, N-(4-glycidyloxyphenyl)maleimide, N-glycidyloxymaleimide, 3-maleimidebenzoic acid, 3-maleimidepropionic acid, 3-(2,5-dioxo-3-pyrrolidin-1-yl)benzoic acid, and 4-(2,5-dioxo-3-pyrrolidin-1-yl)benzoic acid methyl ester. In addition, as a monomer having a polymerizable unsaturated bond, a compound having a photo-orientation group can also be used. As a monomer having a polymerizable unsaturated bond, one can be used alone or two or more can be used in combination.

[0070] The polymer (Pm) can be obtained, for example, by polymerizing a monomer having a polymerizable unsaturated bond in the presence of a polymerization initiator. As the polymerization initiator used, for example, azo compounds such as 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), and 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) are preferred. The use ratio of the polymerization initiator is preferably set to 0.01 to 30 parts by mass relative to 100 parts by mass of all monomers used in the reaction. The polymerization reaction is preferably carried out in an organic solvent. As the organic solvent used in the reaction, for example, alcohols, ethers, ketones, amides, esters, hydrocarbon compounds, etc., are listed, preferably diethylene glycol ethyl methyl ether, propylene glycol monomethyl ether acetate, etc. The reaction temperature is preferably set to 30°C to 120°C, and the reaction time is preferably set to 1 hour to 36 hours. The amount (a) of the organic solvent used is preferably such that the total amount (b) of the monomers used in the reaction is 0.1% by mass to 60% by mass based on the total amount (a+b) of the reaction solution.

[0071] The polymer (Pm) has a polystyrene-equivalent weight average molecular weight (Mw) measured by GPC, preferably from 250 to 500,000, more preferably from 500 to 100,000.

[0072] When a photo-alignment method is used to impart liquid crystal alignment capability to an organic film formed using a liquid crystal alignment agent, a photo-alignment film can be obtained by setting at least a portion of the polymer components to a polymer having a photo-alignment group. The photo-alignment group refers to a functional group that can impart anisotropy to the film through a photoreaction such as a photoisomerization reaction, a photodimerization reaction, a photoFries rearrangement reaction, or a photodecomposition reaction caused by light irradiation.

[0073] Specific examples of the photo-alignment group include: an azobenzene-containing group containing azobenzene or a derivative thereof as a basic skeleton, a cinnamic acid structure-containing group containing cinnamic acid or a derivative thereof (cinnamic acid structure) as a basic skeleton, a chalcone-containing group containing chalcone or a derivative thereof as a basic skeleton, a benzophenone-containing group containing benzophenone or a derivative thereof as a basic skeleton, a coumarin-containing group containing coumarin or a derivative thereof as a basic skeleton, a cyclobutane-containing structure containing cyclobutane or a derivative thereof as a basic skeleton, a stilbene-containing group using stilbene or a derivative thereof as a basic skeleton, a phenyl benzoate-containing group containing phenyl benzoate or a derivative thereof as a basic skeleton, and the like. Among the above-mentioned groups, the photo-aligning group is preferably at least one selected from the group consisting of a group containing azobenzene, a group containing a cinnamic acid structure, a group containing chalcone, a group containing distilbene, a structure containing cyclobutane, and a group containing phenyl benzoate. In terms of high sensitivity to light and easy introduction into a polymer, a group containing a cinnamic acid structure or a structure containing cyclobutane is particularly preferred.

[0074] The polymer having a photo-orientation group can be obtained, for example, by the following methods, etc.: (1) a method of polymerizing using a monomer having a photo-orientation group; (2) a method of synthesizing a polymer having an epoxy group in a side chain, and reacting the epoxy group-containing polymer obtained by the synthesis with a carboxylic acid having a photo-orientation group. The content ratio of the photo-orientation group in the polymer can be appropriately set according to the type of the photo-orientation group in order to impart the desired liquid crystal orientation ability to the coating film. For example, in the case of a group containing a cinnamic acid structure, the content ratio of the photo-orientation group is preferably set to 5 mol% or more, and more preferably to 10 mol% to 60 mol% relative to all structural units of the polymer having a photo-orientation group. In the case where the photo-orientation group is a cyclobutane-containing structure, the content ratio of the photo-orientation group is preferably set to 50 mol% or more, and more preferably to 80 mol% or more relative to all structural units of the polymer having a photo-orientation group. In addition, as a polymer having a photo-orientation group, one type can be used alone, or two or more types can be used in combination.

[0075] The polymer component contained in the liquid crystal alignment agent may be a single one or multiple ones. For example, the liquid crystal alignment agent contains a first polymer and a second polymer having a higher polarity than the first polymer. In the above case, the second polymer having a higher polarity tends to exist in the lower layer, and the first polymer tends to exist in the upper layer, which can produce phase separation, which is preferred in this respect. As preferred forms of the polymer component of the liquid crystal alignment agent, the following (I) to (III) can be listed.

[0076] (I) The first polymer and the second polymer are in the form of a polymer selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide.

[0077] (II) One of the first polymer and the second polymer is a polymer selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide, and the other is in the form of polyorganosiloxane.

[0078] (III) One of the first polymer and the second polymer is at least one polymer selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide, and the other is a polymer (Pm).

[0079] In the forms of (II) and (III), the total content of polyamic acid, polyamic acid ester and polyimide is preferably 20% by mass or more, more preferably 30% by mass or more, and further preferably 50% by mass to 98% by mass, relative to the total amount of the polymer components contained in the liquid crystal alignment agent, from the viewpoint of obtaining a liquid crystal element having sufficiently high liquid crystal orientation and voltage holding characteristics. In the case of imparting liquid crystal orientation ability to an organic film formed using a liquid crystal alignment agent by a photo-alignment method, by setting at least one selected from the group consisting of polyorganosiloxane, poly(meth)acrylate or styrene-maleimide copolymer as a polymer having a photo-alignment group, an alignment film having better liquid crystal orientation can be obtained, which is preferred in this respect.

[0080] Regarding the content ratio of the polymer component in the liquid crystal alignment agent, from the viewpoint of obtaining a liquid crystal alignment film with high adhesion to the substrate, it is preferably set to 50 mass % or more, more preferably 60 mass % or more, and even more preferably 70 mass % or more, relative to the total mass of solid components contained in the liquid crystal alignment agent (the total mass of components other than the solvent of the liquid crystal alignment agent).

[0081] <Component (B): Compound [B]>

[0082] Compound [B] is a compound having two or more nucleophilic functional groups or acidic functional groups in one molecule, and one or more of the nucleophilic functional groups or acidic functional groups in one molecule has a partial structure [T] formed by bonding a nitrogen atom, a sulfur atom or an oxygen atom with a leaving group that is released by at least one of heat and light (hereinafter, also referred to as "leaving group"). That is, compound [B] has one or more protected nucleophilic functional groups or acidic functional groups. In addition, compound [B] is a component different from the polymer component as component (A).

[0083] The nucleophilic functional group or acidic functional group possessed by compound [B] is preferably a group that reacts with the electrophilic functional group possessed by compound [C] by heating (for example, heating during film formation). In addition, in compound [B], the protected nucleophilic functional group and the protected acidic functional group are not particularly limited, but are preferably a group that generates a group that reacts with the electrophilic functional group possessed by compound [C] by heating. Among the multiple nucleophilic functional groups or multiple acidic functional groups possessed by compound [B], in terms of further improving the storage stability of the liquid crystal alignment agent, it is preferred that more than half of the nucleophilic functional groups possessed by compound [B] are protected, and particularly preferably all are protected.

[0084] When compound [B] is a compound having two or more nucleophilic functional groups in one molecule (hereinafter also referred to as "compound [B1]"), compound [B1] is preferably a compound having two or more protected nucleophilic functional groups, among which a compound represented by the following formula (1) is preferred.

[0085] [Chemistry 2]

[0086]

[0087] (In formula (1), X 1 Y is a nitrogen atom, a sulfur atom, an oxygen atom, or a group represented by the following formula (X-1). 1 A releasing group that is released by at least one of heat and light. 1 is a hydrogen atom or a monovalent organic group. 2 is a k-valent organic group. k is an integer greater than 2. 1 When X is a sulfur atom or an oxygen atom, m is 1 and n is 0. 1 When it is a nitrogen atom or a group represented by the following formula (X-1), m is 1 or 2, and n is 2-m. 1 The same or different from each other. 1 In the case of multiple Y 1 Same as or different from each other.)

[0088] [Chemistry 3]

[0089]

[0090] (In formula (x-1), R 3 is a hydrogen atom or a monovalent hydrocarbon group with 1 to 10 carbon atoms. "*" indicates a bond. "*1" indicates a bond with R 2 )

[0091] In the formula (1), when X 1When it is a group represented by the formula (x-1), R in the formula (x-1) 3 Examples of the monovalent hydrocarbon group include an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aralkyl group having 6 to 10 carbon atoms. 3 It is preferably a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a phenyl group, and more preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

[0092] In terms of high cross-linking reactivity, among the above, X 1 A nitrogen atom, a sulfur atom or a group represented by the formula (x-1) is preferred, and a nitrogen atom or a group represented by the formula (x-1) is more preferred in terms of high reworkability.

[0093] Y 1 Preferably, it is a group that is released by heat. 1 When Y is a nitrogen atom or a group represented by the formula (x-1), 1 , for example, carbamate protecting groups, amide protecting groups, imide protecting groups, sulfonamide protecting groups, etc. Among the above groups, carbamate protecting groups are preferred in terms of high heat-induced detachment, and specific examples thereof include tert-butoxycarbonyl, benzyloxycarbonyl, 1,1-dimethyl-2-haloethyloxycarbonyl, 1,1-dimethyl-2-cyanoethyloxycarbonyl, 9-fluorenylmethyloxycarbonyl, allyloxycarbonyl, 2-(trimethylsilyl)ethoxycarbonyl, etc. Among the above groups, tert-butoxycarbonyl (Boc (t-Butyloxy carbonyl) group) is particularly preferred in terms of excellent heat-induced detachment and the ability to reduce the amount of the compound derived from the deprotected structure remaining in the film.

[0094] When X 1 When it is an oxygen atom or a sulfur atom, Y 1 For example, ether protecting groups such as methyl, ethyl, tert-butyl, benzyl, p-methoxybenzyl, trityl, etc.; acetal protecting groups such as methoxymethyl, ethoxyethyl, 2-tetrahydropyranyl, etc.; acyl protecting groups such as acetyl, pivaloyl, benzoyl, trichloroacetyl, etc.; allyl protecting groups such as allyl, methylallyl, etc.; carbamate protecting groups such as tert-butyloxycarbonyl, etc.; silyl ether protecting groups such as trimethylsilyl, triethylsilyl, tert-butyldimethylsilyl, etc. From the perspective of achieving both ease of thermal release and storage stability, when X 1 When Y is an oxygen atom or a sulfur atom, 1 Preferred is an alkyl group having 1 to 7 carbon atoms, 2-tetrahydropyranyl, methoxymethyl, 1-ethoxyethyl or acetyl.

[0095] R 1The monovalent organic group is preferably a monovalent hydrocarbon group having 1 to 12 carbon atoms. 1 It is preferably a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, and more preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

[0096] R 2 The k-valent organic group is preferably one that does not hinder X 1 The nucleophilic structure of 2 In the formula (R), the k-valent organic group preferably has 1 to 40 carbon atoms. 2 Examples of the k-valent organic group include a k-valent hydrocarbon group having 1 to 40 carbon atoms, a hydrocarbon group containing -O-, -S-, -CO-, -COO-, -NR 4 -、-CO-NR 4 -、-NR 4 -CO-O-, -NR 4 -CO-NR 5 -、-CO-NR 4 -NR 5 - or a heterocyclic k-valent group (wherein R 4 and R 5 Each independently represents a hydrogen atom or a monovalent organic group. The same applies hereinafter). Here, as the hydrocarbon group having 1 to 40 carbon atoms, there are listed: a chain hydrocarbon group, an alicyclic hydrocarbon group and an aromatic hydrocarbon group. Among the above groups, a chain hydrocarbon group is preferred in terms of having higher crosslinking reactivity and being able to form a film with high adhesion to the substrate. 4 and R 5 The monovalent organic group is preferably a monovalent hydrocarbon group or a protecting group having 1 to 10 carbon atoms, more preferably a monovalent hydrocarbon group or a protecting group having 1 to 6 carbon atoms, and further preferably an alkyl group or a tert-butoxycarbonyl group having 1 to 6 carbon atoms.

[0097] In terms of higher crosslinking reactivity, good electrical properties and high-adhesion oriented films can be obtained, R 2 It is preferably a k-valent group having no aromatic ring. 2 It is preferably a k-valent chain hydrocarbon group, or the chain hydrocarbon group contains -O-, -S-, -CO-, -COO-, -NR 4 -、-CO-NR 4 -、-NR 4 -CO-O-, -NR 4 -CO-NR 5 -、-CO-NR 4 -NR 5- or a k-valent group of a non-aromatic heterocyclic ring. Here, the k-valent chain hydrocarbon group preferably has 2 to 30 carbon atoms, and more preferably has 3 to 20 carbon atoms. The non-aromatic heterocyclic ring is preferably a nitrogen-containing ring, and examples thereof include a piperidine ring, a pyrrolidine ring, a hexamethyleneimine ring, a morpholine ring, an isocyanurate ring, and the like. 2 Preferred specific examples include structures represented by the following formulae (r-1) to (r-4), and the like.

[0098] [Chemistry 4]

[0099]

[0100] (In formula (r-1) to formula (r-4), t is an integer of 0 to 18. 2 and X 3 are independently -O-, -S-, -CO-, -COO-, -NR 4 -、-CO-NR 4 -、-NR 4 -CO-O-, -NR 4 -CO-NR 5 -, or -CO-NR 4 -NR 5 -. t1, t2 and t3 are each independently an integer of 1 to 10. u is an integer of 0 to 3. R 20 is a divalent group represented by the formula (r-1) or the formula (r-2). "*" represents a bonding bond.

[0101] When X 1 When it is a nitrogen atom or a group represented by the above formula (x-1), m is preferably 1 from the viewpoint of improving reworkability while maintaining favorable liquid crystal orientation and electrical properties.

[0102] From the viewpoint of achieving both liquid crystal orientation and electrical characteristics and reworkability, k is preferably 2 to 10, more preferably 2 to 6, further preferably 2 to 4, particularly preferably 2 or 3.

[0103] For compound [B1], when X 1 When X is a nitrogen atom or a group represented by the formula (X-1), and the polymer component has an amino terminal or an amino group in the side chain, the compound [B1] is preferably a compound showing a higher basicity than the basicity of the amino group constituting the polymer component. Specifically, it is preferred that the pka value (in water, 25°C) of the conjugate acid of the amino group of the compound [B1] is greater than the pka value of a general aromatic diamine monomer (specifically, 4 or less), and from the viewpoint of reaction selectivity, the pka value is more preferably 6 or more (Δpka≧2). In addition, when X 1When X is an oxygen atom or a sulfur atom, and the polymer component has a hydroxyl-containing monomer, the compound [B1] is preferably a compound showing an acidity lower than that of the hydroxyl-containing monomer constituting the polymer component. Generally, the hydroxyl component of the polymer component is a carboxylic acid (pka=4-5), and the pka value of the OH group and SH group of the compound [B1] is preferably 6 or more (Δpka≧2). 1 When X is an oxygen atom or a sulfur atom, 1 As a specific base, heterocyclic compounds such as pyridine and pyrimidine derivatives; and aliphatic amines such as triethylamine can be preferably used.

[0104] Specific examples of the compound [B1] include compounds represented by the following formula (b1) to formula (b13), and the like.

[0105] [Chemistry 5]

[0106]

[0107] [Chemistry 6]

[0108]

[0109] When compound [B] is a compound having two or more acidic functional groups in one molecule (hereinafter also referred to as "compound [B2]"), compound [B2] is preferably a compound represented by the following formula (3).

[0110] [Chemistry 7]

[0111]

[0112] (In formula (3), X 2 is a carboxylic acid group, a phosphoric acid group, a phosphorous acid group or a sulfonic acid group. 3 is a protected carboxylic acid group, a protected phosphoric acid group, a protected phosphite group or a protected sulfonic acid group. 6 is an organic group with a valence of (i+j). i is an integer greater than 0. j is an integer greater than 1. Wherein (i+j)≧2 is satisfied. When i is greater than 2, a plurality of X 2 When j is 2 or more, multiple X 3 Same or different from each other.)

[0113] In the formula (3), X 3 A group formed by replacing the hydrogen atom of the OH group contained in the carboxylic acid group, phosphoric acid group, phosphorous acid group or sulfonic acid group with a leaving group, and having "*-OL 1 " represented by the group (wherein, L 1is a leaving group, and “*” represents a bonding bond). 1 Specific examples of the group represented by " are preferably acetal-based protecting groups and cyclic alcohol-based protecting groups, and examples thereof include groups represented by the following formulae (L1-1) to (L1-8), respectively.

[0114] [Chemistry 8]

[0115]

[0116] (In formula (L1-1) to formula (L1-8), "*" represents a bonding bond.)

[0117] R 6 The (i+j)-valent organic group is preferably one that does not hinder X 2 and X 3 The nucleophilic structure of 6 The (i+j)-valent organic group preferably has 1 to 40 carbon atoms. 6 The (i+j)-valent organic group includes: a (i+j)-valent hydrocarbon group having 1 to 40 carbon atoms, a hydrocarbon group containing -O-, -S-, -CO-, -COO-, -NR 7 -、-CO-NR 7 -、-NR 7 -CO-O-, -NR 7 -CO-NR 8 -、-CO-NR 7 -NR 8 - or a heterocyclic (i+j) valent group, etc. 7 and R 8 The monovalent organic group is preferably a monovalent hydrocarbon group or a protecting group having 1 to 10 carbon atoms, more preferably a monovalent hydrocarbon group or a protecting group having 1 to 6 carbon atoms, and further preferably an alkyl group or a tert-butoxycarbonyl group having 1 to 6 carbon atoms.

[0118] In terms of higher crosslinking reactivity, good electrical properties and high-adhesion oriented films can be obtained, R 6 It is preferably a (i+j)-valent group having no aromatic ring. 6 It is preferably a (i+j)-valent chain hydrocarbon group, or a chain hydrocarbon group containing -O-, -S-, -CO-, -COO-, -NR 7 -、-CO-NR 7 -、-NR 7 -CO-O-, -NR 7 -CO-NR 8 -、-CO-NR 7 -NR 8- or a (i+j)-valent group of a non-aromatic heterocyclic ring, or a (i+j)-valent alicyclic hydrocarbon group. Here, the (i+j)-valent chain hydrocarbon group preferably has 2 to 30 carbon atoms, and more preferably has 3 to 20 carbon atoms. The non-aromatic heterocyclic ring is preferably a nitrogen-containing ring, and examples thereof include a piperidine ring, a pyrrolidine ring, a hexamethyleneimine ring, a morpholine ring, an isocyanurate ring, and the like.

[0119] From the viewpoint of the adhesion of the liquid crystal alignment film, R 6 It is preferably a (i+j)-valent chain hydrocarbon group, or a chain hydrocarbon group containing -O-, -S-, -CO-, -COO-, -NR 7 -、-CO-NR 7 -、-NR 7 -CO-O-, -NR 7 -CO-NR 8 -、-CO-NR 7 -NR 8 - or a non-aromatic heterocyclic (i+j)-valent group.

[0120] Specific examples of compound [B2] include compounds in which at least one of the acidic groups of polyfunctional carboxylic acids, polyfunctional phosphoric acids, polyfunctional phosphorous acids, and polyfunctional sulfonic acids is protected. Among these compounds, compounds in which at least one of the carboxyl groups of polyfunctional carboxylic acids is protected can be preferably used in terms of high reactivity with compound [C].

[0121] Specific examples of compound [B2] include compounds in which at least one of the carboxyl groups of dicarboxylic acids such as fumaric acid, malonic acid, adipic acid, terephthalic acid, isophthalic acid, sebacic acid, diphenyl ether-4,4'-dicarboxylic acid, and pyridine-2,6-dicarboxylic acid is protected;

[0122] A compound in which at least one of the carboxyl groups of a tricarboxylic acid such as 1,2,4-butanetricarboxylic acid, 1,2,3-cyclohexanetricarboxylic acid, trimellitic acid, or 1,2,4-naphthalenetricarboxylic acid is protected;

[0123] A compound in which at least one of the carboxyl groups of a tetracarboxylic acid such as 1,2,3,4-cyclobutanetetracarboxylic acid, 2,3,5-tricarboxycyclopentylacetic acid, cyclopentanetetracarboxylic acid, cyclohexanetetracarboxylic acid, and pyromellitic acid is protected;

[0124] Compounds represented by the following formula (b2-1) to formula (b2-3), etc.

[0125] [Chemistry 9]

[0126]

[0127] (In formula (b2-1) to formula (b2-3), multiple L 2 Each of L is independently a hydrogen atom, a monovalent hydrocarbon group having 1 to 5 carbon atoms, or a thermally detachable group. 2 At least one of them is a thermally detachable group.)

[0128] Regarding the content of compound [B] in the liquid crystal aligning agent of the present disclosure, from the perspective of obtaining a liquid crystal element having good storage stability of the liquid crystal aligning agent, excellent liquid crystal orientation, electrical properties, and excellent reprocessability, relative to the total amount of 100 parts by mass of the polymer component contained in the liquid crystal aligning agent, preferably 0.5 parts by mass or more. Relative to the total amount of 100 parts by mass of the polymer component, the content of compound [B] is more preferably 1 part by mass or more, and further preferably 2 parts by mass or more. In addition, from the perspective of suppressing the decline in reprocessability, relative to the total amount of 100 parts by mass of the polymer component, the content of compound [B] is preferably 20 parts by mass or less, and more preferably 15 parts by mass or less. As compound [B], one may be used alone, or two or more may be used in combination.

[0129] <Component (C): Compound [C]>

[0130] Compound [C] is a compound having two or more electrophilic functional groups in one molecule (except compounds having a free radical polymerizable carbon-carbon double bond). Compound [C] is a component different from the polymer component (A). The electrophilic functional group of compound [C] is preferably a group that reacts with the nucleophilic functional group of compound [B] by heating (e.g., heating during film formation).

[0131] When compound [B] is compound [B1], compound [C] is preferably a compound having at least one selected from the group consisting of an isocyanate group, a protected isocyanate group, a cyclic carbonate group, a hydroxymethyl group, a protected hydroxymethyl group, a group having an enone structure, and a group having a Meldrum's acid structure as an electrophilic functional group (hereinafter, also referred to as "compound [C1]"). Among them, the electrophilic functional group possessed by compound [C1] is more preferably at least one selected from the group consisting of an isocyanate group, a protected isocyanate group, a hydroxymethyl group, a protected hydroxymethyl group, a group having an enone structure, and a group having a Meldrum's acid structure.

[0132] In the protected isocyanate group, the protecting group is preferably a group that is detached by heat. The protected isocyanate group can be introduced into the compound by reacting the isocyanate group with a blocking agent. As the blocking agent, a known blocking agent can be used, for example, alcohol compounds, phenol compounds, active methylene compounds, thiol compounds, amide compounds, imide compounds, imidazole compounds, pyrazole compounds, urea compounds, oxime compounds, amine compounds, imine compounds, pyridine compounds, etc. From the perspective of suppressing the remaining of the component derived from the group detached by heating during film formation in the film, the number of carbon atoms in the protecting group in the protected isocyanate group is preferably 1 to 10, more preferably 1 to 6.

[0133] Examples of the protecting group in the protected hydroxymethyl group include the group X in compound [B1] 1 When Y is an oxygen atom 1 And the base illustrated.

[0134] The number of electrophilic functional groups possessed by the compound [C1] is preferably 2 to 10, more preferably 2 to 8, from the viewpoint of achieving both liquid crystal orientation and electrical properties and reprocessability and suppressing a decrease in storage stability.

[0135] The molecular weight of the compound [C1] is preferably 1,000 or less, more preferably 800 or less, and even more preferably 650 or less.

[0136] As the compound [C1], a compound represented by the following formula (2) can be preferably used.

[0137] (Z 1 ) m -R 6 …(2)

[0138] (In formula (2), Z 1 is an isocyanate group, a protected isocyanate group, a cyclic carbonate group, a hydroxymethyl group, a protected hydroxymethyl group, a group having an enone structure, or a group having a Michaelis acid structure. 6 is an m-valent organic group. m is an integer greater than 2.)

[0139] In the formula (2), R 6 The m-valent organic group preferably has 1 to 40 carbon atoms. 6 The m-valent organic group may include: an m-valent hydrocarbon group having 1 to 40 carbon atoms; at least one methylene group of the hydrocarbon group is substituted by -O-, -S-, -CO-, -COO-, -NR 4 -、-CO-NR 4 -、-NR 4 -CO-O-, -NR 4 -CO-NR5 -、-CO-NR 4 -NR 5 - or an m-valent group substituted with a heterocyclic ring, etc.

[0140] Z 1 An isocyanate group, a protected isocyanate group, a methylol group, a protected methylol group, a group having an enone structure, or a group having a Michaelis acid structure is preferred. m is preferably 2-10, and more preferably 2-8.

[0141] Specific examples of the compound [C1] include compounds represented by the following formula (c1) to formula (c15), and the like.

[0142] [Chemistry 10]

[0143]

[0144] [Chemistry 11]

[0145]

[0146] [Chemistry 12]

[0147]

[0148] (In formula (c1), formula (c2) and formula (c4), R 7 is a protecting group. 11 , R 12 and R 13 One of them is a methyl group and the rest are hydrogen atoms. 14 , R 15 and R 16 One of them is a methyl group and the rest are hydrogen atoms. 17 , R 18 and R 19 One of them is a methyl group and the rest are hydrogen atoms.)

[0149] When compound [B] is compound [B2], compound [C] is preferably a compound containing at least one electrophilic functional group selected from the group consisting of a cyclic ether group, a cyclic carbonate group, an oxazoline group, and a group having a β-hydroxyamide structure (hereinafter, also referred to as "compound (C2)") in terms of high crosslinking reactivity and the ability to obtain a liquid crystal element having excellent liquid crystal orientation and electrical properties. Here, as the cyclic ether group, oxacyclopropyl group, oxacyclobutyl group, etc. can be cited. The group having a β-hydroxyamide structure is preferably a β-hydroxyalkylamide group.

[0150] Among the above groups, the electrophilic functional group possessed by compound [C2] is preferably at least one selected from the group consisting of a cyclic ether group, a cyclic carbonate group and a group having a β-hydroxyamide structure, and more preferably at least one selected from the group consisting of a cyclic carbonate group and a group having a β-hydroxyamide structure.

[0151] The number of electrophilic functional groups possessed by the compound [C2] is preferably 2 to 10, more preferably 2 to 8, from the viewpoint of achieving both liquid crystal orientation and electrical properties and reprocessability and suppressing a decrease in storage stability.

[0152] The molecular weight of the compound [C2] is preferably 1,000 or less, more preferably 800 or less, and even more preferably 650 or less.

[0153] Preferred examples of the compound [C2] include compounds represented by the following formula (4).

[0154] [Chemistry 13]

[0155]

[0156] (In formula (4), Z 1 is a cyclic ether group, a cyclic carbonate group, an oxazoline group, or a β-hydroxyalkylamide group. 10 It is an r-valent organic group having 1 to 40 carbon atoms. r is an integer of 2 to 10.

[0157] In the formula (4), R 10 For example, there can be listed: a hydrocarbon group; a group formed by replacing any methylene group of a hydrocarbon group by -O-, -S-, -CO-, -COO-, etc. (hereinafter, also referred to as a "heteroatom-containing group"); a group formed by replacing any hydrogen atom possessed by a hydrocarbon group or a heteroatom-containing group by a hydroxyl group, a halogen atom, a cyano group, a nitro group, etc.; and a group having a heterocyclic structure, etc.

[0158] In terms of higher crosslinking reactivity, good electrical properties and high-adhesion oriented films can be obtained, R 10 It is preferably an r-valent group having no aromatic ring. 10 It is preferably an r-valent chain hydrocarbon group, or an r-valent group containing -O-, -S-, -CO-, -COO- or a non-aromatic heterocyclic ring between the carbon-carbon bonds of the chain hydrocarbon group. Here, the r-valent chain hydrocarbon group preferably has 2 to 30 carbon atoms, more preferably 3 to 20 carbon atoms. The non-aromatic heterocyclic ring is preferably a nitrogen-containing ring, for example, a piperidine ring, a pyrrolidine ring, a hexamethyleneimine ring, a morpholine ring, an isocyanurate ring, etc. As R 10 Preferred specific examples include the structures represented by the above-mentioned formula (r-1) to formula (r-4), etc.

[0159] Specific examples of compound [C2] include compounds having a cyclic ether group: ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerol diglycidyl ether, trimethylolpropane triglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, N,N,N',N'- Tetraglycidyl-p-phenylenediamine, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenyl ether, N,N,N',N'-tetraglycidyl-2,2'-dimethyl-4,4'-diaminobiphenyl, trimethylolpropane triglycidyl ether, N,N,N',N'-tetraglycidyl-m-phenylenediamine, 1 ,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylpentane, N,N-diglycidyl-benzylamine, N,N-diglycidyl-aminomethylcyclohexane, N,N-diglycidyl-cyclohexylamine, N,N,N',N' - tetraglycidyl-1,4-diaminocyclohexane, bis(N,N-diglycidyl-4-aminocyclohexyl)methane, 1,4-bis(N,N-diglycidylaminomethyl)cyclohexane, 1,4-bis(N,N-diglycidylaminomethyl)benzene, 1,3,5-tris(N,N-diglycidylaminomethyl)cyclohexane, compounds represented by the following formulas (c2-1) to (c2-9), etc.

[0160] [Chemistry 14]

[0161]

[0162] (In formula (c2-5), a is an integer from 1 to 3.)

[0163] Specific examples of the compound having a cyclic carbonate group include compounds represented by the following formula (c2-10) to formula (c2-16), and the like.

[0164] [Chemistry 15]

[0165]

[0166] (In formula (c2-16), b is an integer from 1 to 10.)

[0167] Specific examples of the compound having an oxazoline group or a protected oxazoline group (β-hydroxyamide group) include compounds represented by the following formula (c2-17) to (c2-21), respectively.

[0168] [Chemistry 16]

[0169]

[0170] Regarding the content of compound [C] in the liquid crystal aligning agent of the present disclosure, from the viewpoint of obtaining a liquid crystal element having excellent liquid crystal orientation and electrical properties, it is preferably 0.5 parts by mass or more relative to 100 parts by mass of the total amount of the polymer component contained in the liquid crystal aligning agent. The content of compound [C] is more preferably 1 part by mass or more, and more preferably 2 parts by mass or more relative to 100 parts by mass of the total amount of the polymer component. In addition, from the viewpoint of suppressing the decline in reprocessability, the content of compound [C] is preferably 20 parts by mass or less, and more preferably 15 parts by mass or less relative to 100 parts by mass of the total amount of the polymer component. As compound [C], one may be used alone, or two or more may be used in combination.

[0171] Regarding the ratio of compound [B] to compound [C] in the liquid crystal alignment agent, relative to 100 parts by mass of compound [B], compound [C] is preferably 20 parts by mass to 500 parts by mass, and more preferably 30 parts by mass to 300 parts by mass. In addition, regarding the total amount of compound [B] and compound [C], from the perspective of fully obtaining the improvement effect of liquid crystal orientation and electrical properties, relative to 100 parts by mass of the total amount of polymer components contained in the liquid crystal alignment agent, it is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and further preferably 5 parts by mass or more. On the other hand, from the perspective of suppressing the decline in reprocessability, relative to 100 parts by mass of the total amount of polymer components, the total amount of compound [B] and compound [C] is preferably 40 parts by mass or less, and more preferably 30 parts by mass or less.

[0172] The combination of compound [B] and compound [C] is not particularly limited, and any one or more of the compounds [B] and any one or more of the compounds [C] may be used in appropriate combination. From the viewpoint of promoting the crosslinking reaction and improving the liquid crystal orientation and electrical properties of the resulting liquid crystal element, it is preferred to use compound [B1] in combination with compound [C1], or to use compound [B2] in combination with compound [C2].

[0173] When the compound [B1] and the compound [C1] are used in combination, it is preferred that only one of the compound [B1] and the compound [C1] has a portion different from the protected nucleophilic functional group (specifically, R in the formula (1)) in order to ensure reprocessability by an appropriate crosslinking density and to improve the liquid crystal orientation and electrical properties of the obtained liquid crystal element. 1 and R 2 )), or a portion different from the protected electrophilic functional group (specifically, R in the formula (2) 6 ) does not have a benzene ring, a naphthalene ring, a cyclohexane ring and an isocyanurate ring, or compound [B] and compound [C] do not have any of a benzene ring, a naphthalene ring, a cyclohexane ring and an isocyanurate ring in the part different from the protected nucleophilic functional group and the part different from the protected electrophilic functional group. Among them, from the aspect of maintaining the reprocessability, liquid crystal orientation and electrical properties in a good balance and improving the freedom of selection of the compound, it is preferred that only one of compound [B] and compound [C] does not have one or more of a benzene ring, a naphthalene ring, a cyclohexane ring and an isocyanurate ring in the part different from the protected nucleophilic functional group and the part different from the protected electrophilic functional group.

[0174] <Other ingredients>

[0175] The liquid crystal alignment agent of the present disclosure may also contain components other than polymer components, compound [B] and compound [C] (hereinafter, also referred to as other compounds) as needed. As specific examples thereof, functional silane compounds (for example, 3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, etc.), antioxidants, metal chelate compounds, hardening accelerators, surfactants, fillers, dispersants, photosensitizers, etc. In addition, the content of other compounds can be appropriately selected according to each compound within the range that does not damage the effect of the present disclosure.

[0176] (Solvent)

[0177] The liquid crystal alignment agent disclosed herein is prepared in the form of a liquid composition, wherein the liquid composition is prepared by dissolving a polymer component, a compound [B], a compound [C], and optionally a component prepared in a solvent. The solvent is preferably an organic solvent, for example, an aprotic polar solvent, a phenolic solvent, an alcohol, a ketone, an ester, an ether, a halogenated hydrocarbon, a hydrocarbon, etc.

[0178] Specific examples of the organic solvent used include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 1,2-dimethyl-2-imidazolidinone, γ-butyrolactone, γ-butyrolactam, N,N-dimethylformamide, N,N-dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone (diacetone alcohol), 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 isopropyl ether, ethylene glycol n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diisobutyl ketone, isopentyl propionate, isopentyl isobutyrate, diisoamyl ether, ethylene carbonate, propylene carbonate, cyclohexanone, 3-methoxy-1-butanol, etc. These can be used alone or in combination of two or more.

[0179] The solid content concentration in the liquid crystal aligning agent (the ratio of the total mass of the components of the liquid crystal aligning agent other than the solvent in the total mass of the liquid crystal aligning agent) can be appropriately selected considering viscosity, volatility, etc., preferably in the range of 1% to 10% by mass. If the solid content concentration is 1% by mass or more, the film thickness of the coating can be fully ensured, and there is a tendency to obtain a good liquid crystal aligning film. In addition, if the solid content concentration is 10% by mass or less, the film thickness of the coating will not be excessively increased, and in addition, the viscosity of the liquid crystal aligning agent can be appropriately increased, and there is a tendency to make the coating property good.

[0180] 《Liquid crystal alignment film and liquid crystal element》

[0181] The liquid crystal alignment film of the present invention is formed by a liquid crystal alignment agent prepared as described above. In addition, the liquid crystal element of the present invention includes a liquid crystal alignment film formed using the liquid crystal alignment agent described above. The operating mode of the liquid crystal in the liquid crystal element is not particularly limited, for example, it can be applied to various modes such as twisted nematic (TN), super twisted nematic (STN), vertical alignment (VA) (including vertical alignment-multi-domain vertical alignment (VA-MVA), vertical alignment-patterned vertical alignment (VA-PVA), etc.), in-plane switching (IPS), fringe field switching (FFS), optically compensated bend (OCB), polymer stabilized alignment (PSA), etc. The liquid crystal element can be manufactured, for example, by a method including the following steps 1 to 3. In step 1, the substrate used varies depending on the desired operation mode. Steps 2 and 3 are common to all operation modes.

[0182] <Step 1: Formation of coating film>

[0183] First, a liquid crystal alignment agent is applied to the substrate, and the coated surface is preferably heated to form a coating film on the substrate. As a substrate, for example, a transparent substrate comprising the following materials can be used: glass such as float glass and soda glass; resins such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, and poly (alicyclic olefin). As a transparent conductive film disposed on one surface of the substrate, a NESA film (registered trademark of PPG, USA) containing tin oxide (SnO2) and an indium tin oxide (Indium Tin Oxide, ITO) film containing indium oxide-tin oxide (In2O3-SnO2) can be used. In the case of manufacturing a TN type, STN type or VA type liquid crystal element, two substrates provided with a patterned transparent conductive film are used. On the other hand, in the case of manufacturing an IPS type or FFS type liquid crystal element, a substrate provided with electrodes patterned into a comb-shaped shape and an opposing substrate without electrodes are used. The liquid crystal aligning agent is applied to the substrate on the electrode formation surface preferably by an offset printing method, a flexographic printing method, a spin coating method, a roll coater method or an inkjet printing method.

[0184] After applying the liquid crystal alignment agent, it is preferred to perform preheating (prebaking) for the purpose of preventing dripping of the applied liquid crystal alignment agent. The prebaking temperature is preferably 30°C to 200°C, and the prebaking time is preferably 0.25 minutes to 10 minutes. Then, a calcination (post-baking) step is performed for the purpose of completely removing the solvent. The calcination temperature (post-baking temperature) at this time is preferably 80°C to 250°C, and more preferably 80°C to 200°C. The post-baking time is preferably 5 minutes to 200 minutes. The film thickness of the film formed in this way is preferably 0.001μm to 1μm.

[0185] <Step 2: Orientation treatment>

[0186] In the case of manufacturing TN type, STN type, IPS type or FFS type liquid crystal elements, the coating formed in the step 1 is subjected to a treatment (orientation treatment) of imparting liquid crystal orientation ability. Thus, the coating is given the orientation ability of liquid crystal molecules and becomes a liquid crystal orientation film. As an orientation treatment, the following treatment can be used: a friction treatment in which a roller of a cloth containing fibers such as nylon, rayon, and cotton is wound around the coating formed on the substrate in a certain direction, or a light orientation treatment in which the coating formed on the substrate is irradiated with light and the coating is given liquid crystal orientation ability. On the other hand, in the case of manufacturing a vertically oriented (VA) type liquid crystal element, the coating formed in the step 1 can be directly used as a liquid crystal orientation film, but in order to further improve the liquid crystal orientation ability, the coating can also be subjected to an orientation treatment. The preferred liquid crystal orientation film for a vertically oriented liquid crystal element is also preferred for a PSA type liquid crystal element.

[0187] In the photo-alignment treatment, light irradiation can be carried out by the following methods, etc.: a method of irradiating the coating after the post-baking step, a method of irradiating the coating after the pre-baking step and before the post-baking step, and a method of irradiating the coating during the heating process of the coating in at least any one of the pre-baking step and the post-baking step. As radiation irradiated to the coating, for example, ultraviolet rays and visible light containing light with a wavelength of 150nm to 800nm ​​can be used. Preferably, ultraviolet rays containing light with a wavelength of 200nm to 400nm are used. In the case where the radiation is polarized, it can be linearly polarized or partially polarized. In the case where the radiation used is linearly polarized or partially polarized, the irradiation can be carried out from a direction perpendicular to the substrate surface, from an inclined direction, or in combination of these directions. The irradiation direction in the case of non-polarized radiation is set to an inclined direction.

[0188] Examples of the light source include a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, and an excimer laser. The radiation dose to the substrate surface is preferably 400 J / m 2 ~50,000J / m 2 , more preferably 1,000 J / m 2 ~20,000J / m 2 After irradiation with light for imparting alignment ability, the substrate surface may be cleaned using water, an organic solvent (e.g., methanol, isopropanol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, etc.) or a mixture thereof, or the substrate may be heated.

[0189] <Step 3: Construction of liquid crystal cell>

[0190] Prepare two substrates with liquid crystal alignment films formed as described above, and manufacture a liquid crystal unit in a manner that a liquid crystal is arranged adjacent to the liquid crystal alignment film between the two substrates. When manufacturing a liquid crystal unit, for example, the following methods can be cited: two substrates are arranged opposite to each other with a gap in a manner that the liquid crystal alignment films face each other, the peripheral portions of the two substrates are bonded together using a sealant, and a method of injecting and filling liquid crystals into the cell gap surrounded by the substrate surface and the sealant and sealing the injection hole, a method using a liquid crystal drop (One Drop Fill, ODF) method, etc. As a sealant, for example, an epoxy resin containing a hardener and alumina balls as a spacer can be used. As liquid crystals, nematic liquid crystals and disc-shaped liquid crystals can be cited, among which nematic liquid crystals are preferred. In the PSA mode, after constructing a liquid crystal unit, the liquid crystal unit is subjected to light irradiation treatment while a voltage is applied between the conductive films possessed by a pair of substrates.

[0191] The PSA type liquid crystal element can be produced by a method including the following steps.

[0192] A step of applying the liquid crystal aligning agent of the present disclosure onto the conductive film of each of a pair of substrates having a conductive film to form a coating film.

[0193] A step of constructing a liquid crystal cell by arranging a pair of substrates coated with a liquid crystal aligning agent so that the coated films face each other with a liquid crystal layer interposed therebetween.

[0194] A step of irradiating the liquid crystal cell with light while a voltage is applied between the conductive films.

[0195] Specifically, first, a liquid crystal and a photopolymerizable monomer are injected or dropped between a pair of substrates having a conductive film, and a liquid crystal cell is constructed in the same manner as in Steps 1 to 3 except for this aspect. As the photopolymerizable monomer injected or dropped with the liquid crystal, a conventionally known compound can be used, preferably a multifunctional (meth)acrylic monomer.

[0196] In the manufacture of a PSA type liquid crystal element, after constructing a liquid crystal unit, the liquid crystal unit is irradiated with light while a voltage is applied between the conductive films of a pair of substrates. The applied voltage can be set to, for example, a direct current or alternating current of 5V to 50V. As the irradiated light, for example, ultraviolet light and visible light containing a wavelength of 150nm to 800nm ​​can be used. Among the light, ultraviolet light containing a wavelength of 300nm to 400nm is preferred. As the light source of the irradiated light, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, an excimer laser, etc. can be used. As the irradiation amount of light, 1,000J / m 2 ~200,000J / m 2 , more preferably 1,000 J / m 2 ~100,000J / m 2 .

[0197] For each mode of the liquid crystal cell, a polarizing plate is then attached to the outer surface of the liquid crystal cell as needed to prepare a liquid crystal element. Examples of the polarizing plate include a polarizing plate obtained by sandwiching a polarizing film called "H film" in which polyvinyl alcohol is stretched and oriented while absorbing iodine, with a cellulose acetate protective film, or a polarizing plate including the H film itself.

[0198] The liquid crystal element disclosed herein can be effectively applied to various purposes, such as clocks, portable game consoles, word processors, notebook personal computers, car navigation systems, camcorders, personal digital assistants (PDAs), digital cameras, mobile phones, smart phones, various monitors, liquid crystal televisions, information displays and other display devices, or dimming films, phase difference films and the like.

[0199] [Example]

[0200] Hereinafter, the present invention will be described in detail by way of examples, but the present invention is not limited to the following examples.

[0201] In the following examples, the solution viscosity, weight average molecular weight (Mw), number average molecular weight (Mn) and imidization ratio of the polymer were measured by the following methods.

[0202] <Solution viscosity of polymer>

[0203] The solution viscosity of the polymer was measured at 25°C using an E-type viscometer.

[0204] <Weight average molecular weight and number average molecular weight>

[0205] Mw and Mn were measured by gel permeation chromatography (GPC) under the following conditions. Molecular weight distribution (Mw / Mn) was calculated from the obtained Mw and Mn.

[0206] Device: Showa Denko Co., Ltd.'s "GPC-101"

[0207] GPC column: Combination of GPC-KF-801, GPC-KF-802, GPC-KF-803 and GPC-KF-804 manufactured by Shimadzu GLC Co., Ltd.

[0208] Mobile phase: tetrahydrofuran (THF)

[0209] Column temperature: 40℃

[0210] Flow rate: 1.0mL / min

[0211] Sample concentration: 1.0 mass%

[0212] Sample injection volume: 100μL

[0213] Detector: Differential refractometer

[0214] Standard material: monodisperse polystyrene

[0215] <Imidization ratio of polyimide>

[0216] The polyimide solution was put into pure water, the obtained precipitate was fully dried under reduced pressure at room temperature, and then dissolved in deuterated dimethyl sulfoxide. The hydrogen nuclear magnetic resonance (HNMR) was performed at room temperature using tetramethylsilane as the reference substance. 1 H-NuclearMagnetic Resonance, 1 H-NMR) determination. 1 The imidization ratio [%] was determined from the H-NMR spectrum using the following formula (1).

[0217] Imidization rate [%] = (1-(β 1 / (β 2 ×α))×100…(1)

[0218] (In formula (1), β 1 is the peak area of ​​the proton origin of the NH group appearing near the chemical shift of 10 ppm, β 2is the peak area of ​​other proton sources, and α is the ratio of the number of other protons relative to one proton of the NH group in the precursor of the polymer (polyamic acid).

[0219] The abbreviations of the compounds used in the following examples are shown below. In addition, for the sake of convenience, the "compound represented by formula (X)" may be simply referred to as "compound (X)".

[0220] Monomer and side chain carboxylic acid

[0221] [Chemistry 17]

[0222]

[0223] [Chemistry 18]

[0224]

[0225] [Chemistry 19]

[0226]

[0227] Compound [B]

[0228] [Chemistry 20]

[0229]

[0230] [Chemistry 21]

[0231]

[0232] Compound [C]

[0233] [Chemistry 22]

[0234]

[0235] (In formula (C-1) and formula (C-2), R is a tert-butyloxycarbonyl group or a group derived from methyl ethyl ketoxime (*-ON=C(CH 3) (C2H5)).

[0236] [Chemistry 23]

[0237]

[0238] [Chemistry 24]

[0239]

[0240] Other additives

[0241] [Chemistry 25]

[0242]

[0243] <Synthesis of polymer>

[0244] 1. Synthesis of polyimide

[0245] [Synthesis example 1]

[0246] 100 molar parts of 2,3,5-tricarboxycyclopentylacetic dianhydride as tetracarboxylic dianhydride, 30 molar parts of cholesteryloxy-2,4-diaminobenzene as diamine, 30 molar parts of 3,5-diaminobenzoic acid and 4,4'-diaminodiphenylmethane were dissolved in N-methyl-2-pyrrolidone (NMP) and reacted at 40°C for 24 hours to obtain a solution containing 20% ​​by mass of polyamic acid. Subsequently, NMP was added to the obtained polyamic acid solution, and 3.00 molar equivalents of pyridine and acetic anhydride were added to the carboxyl groups of the polyamic acid, and a dehydration ring-closure reaction was carried out at 80°C for 4 hours. After the dehydration ring-closure reaction, the solvent in the system was replaced with new γ-butyrolactone and further concentrated to obtain a solution containing 20% ​​by mass of a polyimide having an imidization rate of 71% (hereinafter referred to as polymer (P-1)). A small amount of the solution was aliquoted and NMP was added, and the solution viscosity measured as a solution with a concentration of 10% by mass was 100 mPa·s.

[0247] [Synthesis Example 2, Synthesis Example 5]

[0248] Except that the types and amounts of tetracarboxylic dianhydride and diamine used in the polymerization were changed as shown in Table 1, polymerization was carried out in the same manner as in Synthesis Example 1 to obtain a solution containing a polymer (P-2) or a polymer (P-5) as a polyimide.

[0249] 2. Synthesis of polyamic acid

[0250] [Synthesis example 3]

[0251] 100 parts by mole of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride, 30 parts by mole of compound (D-2) as diamine, 40 parts by mole of compound (D-4), and 30 parts by mole of 3,5-diaminobenzoic acid were dissolved in NMP and reacted at 40° C. for 24 hours to obtain a solution containing 20% ​​by mass of polyamic acid (hereinafter referred to as polymer (P-3)). A small amount of the solution was aliquoted and added to NMP to prepare a solution having a concentration of 10% by mass, and the solution viscosity measured was 80 mPa·s.

[0252] [Synthesis Example 4, Synthesis Example 6 to Synthesis Example 8]

[0253] The types and amounts of tetracarboxylic dianhydride and diamine used in the polymerization were changed as described in Table 1. Except for this aspect, polymerization was carried out in the same manner as in Synthesis Example 3 to obtain solutions containing polymers (P-4), polymers (P-6) to polymers (P-8) as polyamic acids, respectively. In addition, the polymerization was carried out so that the molar ratio of diamine to tetracarboxylic dianhydride (diamine / tetracarboxylic dianhydride) was in the range of 0.95 to 1.00, so that the viscosity of the NMP solution with a polymer concentration of 10% by mass was 80 mPa·s to 100 mPa·s. In Table 1, the numerical value of the anhydride represents the ratio (mol parts) of each compound relative to 100 mol parts of the total amount of tetracarboxylic dianhydride used in the synthesis. The numerical value of the diamine represents the ratio (mol parts) of each compound relative to 100 mol parts of the total amount of the diamine used in the synthesis.

[0254] [Table 1]

[0255]

[0256] 3. Synthesis of polyorganosiloxane

[0257] [Synthesis Example 9]

[0258] 90.0 g of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 500 g of methyl isobutyl ketone and 10.0 g of triethylamine were placed in a 1000 ml three-necked flask and mixed at room temperature. Then, 100 g of deionized water was added dropwise from a dropping funnel over 30 minutes, mixed under reflux and reacted at 80° C. for 6 hours. After the reaction was completed, the organic layer was taken out and washed with a 0.2% by mass aqueous solution of ammonium nitrate until the washed water became neutral, and then the solvent and water were distilled off under reduced pressure. Methyl isobutyl ketone was added in an appropriate amount to obtain a 50% by mass solution of a polymer (ESSQ-1) of a polyorganosiloxane having an epoxy group.

[0259] In a 500 ml three-necked flask, 6.28 g of compound (CA-1) (20 mol% relative to the amount of epoxy groups in polymer (ESSQ-1)), 3.44 g of compound (CA-3) (10 mol% relative to the amount of epoxy groups in polymer (ESSQ-1)), 2.00 g of tetrabutylammonium bromide, 80 g of a solution containing polymer (ESSQ-1), and 239 g of methyl isobutyl ketone were added, and stirred at 90° C. for 18 hours. After cooling to room temperature, liquid separation and washing with distilled water were repeated 10 times. Then, the organic layer was recovered, and after repeated concentration and NMP dilution twice using a rotary evaporator, NMP was used to adjust the solid content concentration to 10% by mass to obtain an NMP solution of polymer (PS-1).

[0260] [Synthesis Example 10]

[0261] An NMP solution containing 10% by mass of a polymer (PS-2) as a polyorganosiloxane was obtained in the same manner as in Synthesis Example 9 except that the type and amount of the side chain carboxylic acid used in the reaction were changed as described in Table 2. In Table 2, the numerical value of the side chain carboxylic acid represents the ratio (side chain modification ratio, mol %) to the amount of epoxy groups possessed by the polymer (ESSQ-1).

[0262] [Table 2]

[0263]

[0264] 4. Synthesis of Styrene-Maleimide Copolymer

[0265] [Synthesis Example 11]

[0266] Under nitrogen, in a 100 mL two-necked flask, 10 moles of compound (M-1) as a polymerization monomer, 10 moles of 4-hydroxystyrene, 35 moles of methacrylic acid and 45 moles of glycidyl methacrylate, 2 moles of 2,2'-azobis(2,4-dimethylvaleronitrile) as a free radical polymerization initiator, and 50 ml of tetrahydrofuran as a solvent were added, and polymerization was carried out at 70°C for 5 hours. After reprecipitation in methanol, the precipitate was filtered and vacuum dried at room temperature for 8 hours to obtain a styrene-maleimide copolymer (hereinafter referred to as polymer (PM-1)). The weight average molecular weight Mw measured by polystyrene conversion using GPC was 30,000, and the molecular weight distribution Mw / Mn was 2.7.

[0267] <Preparation and evaluation of liquid crystal alignment agents>

[0268] [Example 1: PSA type liquid crystal display element]

[0269] (1) Preparation of Liquid Crystal Alignment Agent (AL-1)

[0270] To the solution containing 90 parts by mass of the polymer (P-1) obtained in Synthesis Example 1, a solution containing 10 parts by mass of the polymer (PS-1) obtained in Synthesis Example 9, 5 parts by mass of the compound (B-1), 10 parts by mass of the compound (C-1), and NMP and butyl cellosolve (BC) as solvents were added to prepare a solution having a solvent composition of NMP / BC = 50 / 50 (mass ratio) and a solid content concentration of 4.0% by mass. The solution was filtered using a filter with a pore size of 0.2 μm to prepare a liquid crystal alignment agent (AL-1).

[0271] (2) Preparation of Liquid Crystal Composition

[0272] 5 mass % of a liquid crystal compound represented by the following formula (L1-1) and 0.3 mass % of a photopolymerizable compound represented by the following formula (L2-1) were added to 10 g of a nematic liquid crystal (MLC-6608 manufactured by Merck) and mixed to obtain a liquid crystal composition LC1.

[0273] [Chemistry 26]

[0274]

[0275] (3) Manufacturing of PSA-type liquid crystal display elements

[0276] The liquid crystal alignment agent (AL-1) prepared in the above was applied to each electrode surface of two glass substrates having a conductive film including an ITO electrode patterned into a slit shape using a liquid crystal alignment film printer (manufactured by Nippon Shashin Printing Co., Ltd.), and heated (pre-baked) on a heating plate at 80°C for 2 minutes to remove the solvent, and then heated (post-baked) on a heating plate at 230°C for 10 minutes to form a coating having an average film thickness of 0.06 μm. For the coating, after ultrasonic cleaning in ultrapure water for 1 minute, it was dried in a clean oven at 100°C for 10 minutes to obtain a pair (two pieces) of substrates having a liquid crystal alignment film. In addition, the pattern of the electrode used is a pattern of the same type as the electrode pattern in the PSA mode.

[0277] Then, an epoxy resin adhesive containing alumina balls with a diameter of 5.5 μm is applied to the outer edge of the surface having a liquid crystal alignment film of one of the pair of substrates, and then the surfaces of the liquid crystal alignment films are overlapped and crimped so that the adhesive is cured. Then, the liquid crystal composition LC1 prepared above is filled between the pair of substrates from the liquid crystal injection port, and the liquid crystal injection port is sealed with an acrylic light-curing adhesive, thereby manufacturing a liquid crystal unit. Then, an alternating current of 10 V with a frequency of 60 Hz is applied between the conductive films of the liquid crystal unit, and an ultraviolet irradiation device using a metal halide lamp as a light source is used with a radiation intensity of 100,000 J / m 2 The ultraviolet rays are irradiated at an irradiation amount of . In addition, the irradiation amount is a value measured by a light meter based on a wavelength of 365 nm. Then, polarizing plates are attached to the outer sides of the substrate in such a manner that the polarization directions of the polarizing plates are orthogonal to each other and form an angle of 45° with the optical axis of the ultraviolet rays of the liquid crystal alignment film in the projection direction of the substrate surface, thereby manufacturing a PSA type liquid crystal display element.

[0278] (4) Evaluation of Liquid Crystal Orientation

[0279] For the PSA type liquid crystal display element manufactured as described above, an optical microscope was used to observe whether there was an abnormal domain in the change of light and dark when a voltage of 5V was turned on / off (applied / released), and the liquid crystal orientation was evaluated. When evaluating, the case where there was no abnormal domain was set as "A", the case where there was an abnormal domain in part was set as "B", and the case where there was an abnormal domain as a whole was set as "C". As a result, in the above example, the liquid crystal orientation was evaluated as "A".

[0280] (5) Evaluation of electrical properties using voltage holding ratio (VHR)

[0281] For the PSA type liquid crystal display element manufactured as described above, after applying a voltage of 5V with an application time of 60 microseconds and a span of 167 milliseconds, the voltage holding rate is measured 167 milliseconds after the application is released. The measuring device is VHR-1 manufactured by TOYO Technica (stock). At this time, when the voltage holding rate is 98% or more, it is set to "S", when it is 95% or more and less than 98%, it is set to "A", when it is 80% or more and less than 95%, it is set to "B", when it is 50% or more and less than 80%, it is set to "C", and when it is less than 50%, it is set to "D". As a result, in the embodiment, the electrical characteristics are evaluated as "S".

[0282] (6) Evaluation of film adhesion

[0283] The liquid crystal alignment agent (AL-1) prepared above was applied to a glass substrate using a spinner, and after pre-baking for 2 minutes using a heating plate at 80°C, it was heated for 30 minutes in an oven at 230°C where the air in the box was replaced with nitrogen (post-baking), thereby forming a coating with an average film thickness of 0.10 μm. The same operation was repeated to prepare two glass substrates with a coating formed thereon. On the coating of one glass substrate with a coating formed thereon, an ODF sealant (manufactured by Sekisui Chemical Co., Ltd., S-WB42) was applied in a manner to a width of 1 mm, and the coating of another glass substrate was bonded in a manner such that it was in contact with the ODF sealant. Then, a metal halide lamp was used to irradiate at 30,000 J / m 2 After being exposed to light (converted to 365 nm), the film was heated in an oven at 120°C for 1 hour. Then, the adhesion was measured using a tensile compression tester (model: SDWS-0201-100SL) produced by Imada Manufacturing Co., Ltd. to evaluate the adhesion of the film to the substrate. During the evaluation, the adhesion was set to 175 N / cm 2 The above situation is set as "excellent (S)", and the force is 150N / cm 2 Above and less than 175N / cm 2The case is set as "good (A)", and the value is 125N / cm 2 Above and less than 150N / cm 2 If the value is less than 125 N / cm, set it as "OK (B)" 2 The case of "poor (C)" was set as "bad (C)". As a result, in the above embodiment, the adhesion force was 173N / cm 2 , thus the adhesion is evaluated as "good (A)".

[0284] (7) Evaluation of storage stability

[0285] The change in viscosity of the liquid crystal aligning agent (AL-1) when stored at 23°C for 7 days was measured and compared at 25°C using an E-type viscometer. When evaluating, the viscosity change within ±1% was set as "excellent (S)", the viscosity change within ±3% was set as "good (A)", the viscosity change within ±5% was set as "acceptable (B)", and the viscosity change greater than ±5% was set as "poor (C)". As a result, in the example described above, the viscosity change was +2.5%, which was evaluated as "good (A)" for storage stability.

[0286] (8) Evaluation of reprocessability

[0287] On a transparent conductive film including an ITO film provided on one surface of a glass substrate having a thickness of 1 mm, a liquid crystal alignment agent (AL-1) is applied by a spinner, and pre-baked at 100 ° C for 90 seconds using a hot plate to form a coating having a film thickness of about 0.10 μm. The operation is repeated to form two substrates with coatings. Next, the two obtained substrates are stored in a dark room at 25 ° C under a nitrogen environment. After 12 hours and 48 hours from the start of storage, a substrate is taken out respectively, and after being immersed in a beaker of NMP adjusted to 40 ° C for 2 minutes, it is washed several times with ultrapure water, and water droplets on the surface are removed by blowing. For the substrate, an optical microscope is used to observe whether the coating has residue, thereby evaluating the ease of peeling (reprocessability) of the liquid crystal alignment film from the substrate. In the evaluation, even if the substrate was taken out 48 hours after the start of storage, the case where no residue of the coating film was observed after NMP immersion was rated as "excellent (S)", the case where the residue of the coating film was observed on the substrate after 48 hours but no residue of the coating film was observed on the substrate after 12 hours was rated as "good (A)", the case where very small residue was observed on the substrate after 12 hours was rated as "acceptable (B)", and the case where the residue of the coating film was observed on the substrate after 12 hours was rated as "poor (C)". As a result, in the above-mentioned Example, the reprocessability was rated as "excellent (S)".

[0288] [Example 2 to Example 4 and Comparative Example 1, Comparative Example 2]

[0289] The formulation composition was changed as shown in Table 3. In addition, liquid crystal aligning agents (AL-2) to (AL-4), liquid crystal aligning agents (AR-1), and liquid crystal aligning agents (AR-2) were prepared with the same solvent composition and solid content concentration as in Example 1. In addition, each liquid crystal aligning agent was used to evaluate the storage stability, film adhesion, and reprocessability in the same manner as in Example 1, and a PSA-type liquid crystal display element was manufactured to evaluate the liquid crystal orientation and voltage retention. The evaluation results are shown in Table 3. In addition, in Table 3, "-" indicates that this compound was not used.

[0290] [Example 5: Photovertical liquid crystal display element]

[0291] (1) Preparation of Liquid Crystal Alignment Agent, and Evaluation of Storage Stability, Film Adhesion, and Reprocessability

[0292] The formulation composition was changed as shown in Table 3. Except for this, a liquid crystal aligning agent (AL-5) was prepared with the same solvent composition and solid content concentration as in Example 1. In addition, using the liquid crystal aligning agent (AL-5), the storage stability, film adhesion and reprocessability were evaluated in the same manner as in Example 1. The evaluation results are shown in Table 3.

[0293] (2) Manufacturing of vertical light-type liquid crystal display elements

[0294] The liquid crystal alignment agent (AL-5) prepared above was applied on the transparent electrode surface of a glass substrate with a transparent electrode containing an ITO film using a spinner, and pre-baked for 1 minute using a hot plate at 80°C. Then, in an oven purged of nitrogen, it was heated at 230°C for 1 hour to form a coating with a film thickness of 0.1 μm. Subsequently, a Hg-Xe lamp and a Glan-Taylor prism were used to irradiate the surface of the coating with 1,000 J / m of polarized ultraviolet light containing a bright line of 313 nm from a direction inclined at 40° from the normal line of the substrate. 2 The same operation is repeated to prepare a pair (two sheets) of substrates having liquid crystal alignment films.

[0295] On the periphery of the surface with a liquid crystal alignment film of one of the substrates in the substrate, an epoxy resin adhesive with a diameter of 3.5 μm is applied by screen printing, and then the liquid crystal alignment film surfaces of a pair of substrates are faced to each other, and the optical axis of the ultraviolet rays of each substrate is antiparallel in the projection direction of the substrate surface. The adhesive is thermally cured at 150°C for 1 hour. Then, after filling the negative liquid crystal (Merck, MLC-6608) in the gap between the substrates from the liquid crystal injection port, the liquid crystal injection port is sealed with an epoxy adhesive. Furthermore, in order to remove the flow orientation during liquid crystal injection, it is heated at 130°C and then slowly cooled to room temperature. Then, on the outer two sides of the substrate, the polarizing plates are bonded in a manner such that the polarization directions of the polarizing plates are orthogonal to each other and the optical axis of the ultraviolet rays of the liquid crystal alignment film is at a 45° angle in the projection direction of the substrate surface, thereby manufacturing a light vertical liquid crystal display element.

[0296] (3) Evaluation of Liquid Crystal Orientation

[0297] The photo-vertical liquid crystal display element manufactured as described above was evaluated for liquid crystal orientation in the same manner as in Example 1. As a result, the liquid crystal orientation was evaluated as "A" in the above example.

[0298] (4) Evaluation of electrical properties using voltage holding ratio (VHR)

[0299] The electrical characteristics of the optical vertical type liquid crystal display element manufactured as described above were evaluated in the same manner as in Example 1. As a result, the electrical characteristics were evaluated as "A" in the above example.

[0300] [Comparative Example 3]

[0301] The formulation composition was changed to that shown in Table 3. Except for this, a liquid crystal alignment agent (AR-3) was prepared with the same solvent composition and solid content concentration as in Example 1. In addition, the liquid crystal alignment agent (AR-3) was used to evaluate the storage stability, film adhesion and reprocessability in the same manner as in Example 1, and a photo-vertical liquid crystal display element was manufactured to evaluate the liquid crystal orientation and voltage holding ratio. The evaluation results are shown in Table 3.

[0302] [Example 6: Vertical Liquid Crystal Display Element]

[0303] (1) Preparation of Liquid Crystal Alignment Agent, and Evaluation of Storage Stability, Film Adhesion, and Reprocessability

[0304] The formulation composition was changed as shown in Table 3. Except for this, a liquid crystal aligning agent (AL-6) was prepared with the same solvent composition and solid content concentration as in Example 1. In addition, using the liquid crystal aligning agent (AL-6), the storage stability, film adhesion and reprocessability were evaluated in the same manner as in Example 1. The evaluation results are shown in Table 3.

[0305] (2) Manufacturing of vertical liquid crystal display elements

[0306] The liquid crystal alignment agent (AL-6) prepared above was applied on the transparent electrode surface of the glass substrate with a transparent electrode including an ITO film using a spinner, and pre-baked for 1 minute using a hot plate at 80°C. Then, it was heated at 230°C for 1 hour in an oven purged with nitrogen to form a coating film with a thickness of 0.1 μm. The above operation was repeated to prepare a pair (two sheets) of substrates having a liquid crystal alignment film.

[0307] An epoxy resin adhesive containing alumina balls with a diameter of 3.5 μm was applied by screen printing to the periphery of the surface of one of the substrates having a liquid crystal alignment film, and then the surfaces of the liquid crystal alignment films were overlapped and pressed to cure the adhesive. Then, negative liquid crystal (MLC-6608 manufactured by Merck) was filled between the pair of substrates from the liquid crystal injection port, and the liquid crystal injection port was sealed with an acrylic light-curing adhesive, and polarizing plates were attached to the two surfaces outside the substrates, thereby manufacturing a vertical liquid crystal display element.

[0308] (3) Evaluation of Liquid Crystal Orientation

[0309] The vertical type liquid crystal display element manufactured as described above was evaluated for liquid crystal orientation in the same manner as in Example 1. As a result, the liquid crystal orientation was evaluated as "A" in the above example.

[0310] (4) Evaluation of electrical properties using voltage holding ratio (VHR)

[0311] The vertical liquid crystal display element manufactured as described above was evaluated for electrical characteristics in the same manner as in Example 1. As a result, the electrical characteristics were evaluated as "A" in the above example.

[0312] [Example 7: FFS type liquid crystal display element]

[0313] (1) Preparation of Liquid Crystal Alignment Agent, and Evaluation of Storage Stability, Film Adhesion, and Reprocessability

[0314] The formulation composition was changed as shown in Table 3. Except for this, a liquid crystal aligning agent (AL-7) was prepared with the same solvent composition and solid content concentration as in Example 1. In addition, using the liquid crystal aligning agent (AL-7), the storage stability, film adhesion and reprocessability were evaluated in the same manner as in Example 1. The evaluation results are shown in Table 3.

[0315] (2) Manufacturing of FFS type liquid crystal display elements

[0316] Prepare a glass substrate (set as the first substrate) with a flat electrode (bottom electrode), an insulating layer and a comb-shaped electrode (top electrode) stacked in sequence on one side, and a glass substrate (set as the second substrate) without an electrode. Then, a liquid crystal alignment agent (AL-7) is applied on each surface of the electrode forming surface of the first substrate and the single surface of the second substrate using a spinner, and heated for 3 minutes using a 110°C heating plate (pre-baking). Then, it is dried for 30 minutes in a 230°C oven in which nitrogen is replaced in the box (post-baking) to form a coating with an average film thickness of 0.08 μm. Then, for the surface of the coating, a friction machine with a roller wound with a rayon cloth is used to perform friction treatment at a roller speed of 1000 rpm, a platform moving speed of 3 cm / second, and a hair pressing length of 0.3 mm. Then, ultrasonic cleaning is performed in ultrapure water for 1 minute, followed by drying in a 100°C clean oven for 10 minutes, thereby obtaining a pair of substrates with a liquid crystal alignment film.

[0317] Then, for a pair of substrates with a liquid crystal alignment film, a liquid crystal injection port is reserved at the edge of the surface where the liquid crystal alignment film is formed, and an epoxy resin adhesive with a diameter of 3.5 μm of alumina balls is applied by screen printing. Then, the substrates are overlapped and crimped, and the adhesive is thermally cured at 150°C for 1 hour. Then, after filling the negative liquid crystal (Merck, MLC-6608) in the gap between a pair of substrates from the liquid crystal injection port, the liquid crystal injection port is sealed with an epoxy adhesive. Furthermore, in order to remove the flow orientation during liquid crystal injection, it is heated at 120°C and then slowly cooled to room temperature to manufacture a liquid crystal unit. In addition, when a pair of substrates are overlapped, the rubbing directions of each substrate are made antiparallel. Then, polarizing plates are bonded to the outer two surfaces of the substrate of the liquid crystal unit to obtain an FFS type liquid crystal display element.

[0318] (3) Evaluation of Liquid Crystal Orientation

[0319] The liquid crystal orientation of the FFS type liquid crystal display element manufactured as described above was evaluated in the same manner as in Example 1. As a result, the liquid crystal orientation was evaluated as "A" in the above example.

[0320] (4) Evaluation of electrical properties using voltage holding ratio (VHR)

[0321] The electric characteristics of the FFS liquid crystal display element manufactured as described above were evaluated in the same manner as in Example 1. As a result, the electric characteristics were evaluated as "A" in the above example.

[0322] [Example 8, Example 9 and Comparative Example 4, Comparative Example 5]

[0323] The formulation composition was changed to that shown in Table 3. Except for this aspect, liquid crystal alignment agent (AR-8), liquid crystal alignment agent (AL-9), liquid crystal alignment agent (AR-4), and liquid crystal alignment agent (AR-5) were prepared with the same solvent composition and solid content concentration as in Example 1. In addition, each liquid crystal alignment agent was used to evaluate the storage stability, film adhesion, and reprocessability in the same manner as in Example 1, and an FFS type liquid crystal display element was manufactured to evaluate the liquid crystal orientation and voltage holding ratio. The evaluation results are shown in Table 3.

[0324] [Example 10: Optical FFS Type Liquid Crystal Display Element]

[0325] (1) Preparation of Liquid Crystal Alignment Agent, and Evaluation of Storage Stability, Film Adhesion, and Reprocessability

[0326] The formulation composition was changed to that shown in Table 3. Except for this, a liquid crystal aligning agent (AL-10) was prepared with the same solvent composition and solid content concentration as in Example 1. In addition, using the liquid crystal aligning agent (AL-10), the storage stability, film adhesion, and reprocessability were evaluated in the same manner as in Example 1. The evaluation results are shown in Table 3.

[0327] (2) Manufacturing of optical FFS type liquid crystal display elements

[0328] Prepare the same first substrate and second substrate as in Example 7. Then, apply the liquid crystal alignment agent (AL-10) on each of the electrode-forming surface of the first substrate and one of the substrate surfaces of the second substrate using a spinner, and heat for 1 minute using an 80°C heating plate (pre-baking). Then, dry for 30 minutes in a 230°C oven purged with nitrogen to form a coating with an average film thickness of 0.1 μm. For the obtained coating, use a Hg-Xe lamp to irradiate 1,000 J / m of ultraviolet rays containing a linearly polarized 254 nm bright line from the normal direction of the substrate. 2 The photo-alignment treatment was performed. The irradiation amount was measured using a light meter with a wavelength of 245 nm as a reference. The photo-alignment treated coating was then heated in a clean oven at 230° C. for 30 minutes to form a liquid crystal alignment film.

[0329] Next, for one of the pair of substrates on which a liquid crystal orientation film is formed, an epoxy resin adhesive to which aluminum oxide balls with a diameter of 3.5 μm are added is applied by screen printing on the outer edge of the surface having the liquid crystal orientation film. Then, the substrates are overlapped and crimped in such a way that the projection direction of the polarization axis toward the substrate surface becomes antiparallel when irradiated with light, and the adhesive is thermally cured at 150°C for 1 hour. Next, after a negative liquid crystal (MLC-6608 manufactured by Merck) is filled between a pair of substrates from the liquid crystal injection port, the liquid crystal injection port is sealed with an epoxy adhesive to obtain a liquid crystal unit. Furthermore, in order to remove the flow orientation during liquid crystal injection, it is heated at 120°C and then slowly cooled to room temperature. Then, polarizing plates are bonded to the two outer surfaces of the substrate of the liquid crystal unit to obtain a liquid crystal display element. In addition, the ultraviolet irradiation amount after post-baking is respectively 100 J / m 2 ~10,000J / m 2 The above series of operations are implemented by changing within the range of, thereby manufacturing three or more liquid crystal display elements with different ultraviolet irradiation amounts, and the liquid crystal display element with the exposure amount (optimal exposure amount) showing the best orientation characteristics is used for the following evaluation.

[0330] (3) Evaluation of Liquid Crystal Orientation

[0331] The optical FFS liquid crystal display element manufactured above was evaluated for liquid crystal orientation in the same manner as in Example 1. As a result, in the above example, the liquid crystal orientation was evaluated as "A".

[0332] (4) Evaluation of electrical properties using voltage holding ratio (VHR)

[0333] The electrical characteristics of the optical FFS type liquid crystal display element manufactured as described above were evaluated in the same manner as in Example 1. As a result, the electrical characteristics were evaluated as "A" in the above example.

[0334] [Table 3]

[0335]

[0336] As shown in Table 3, in Examples 1 to 10 in which Compound [B] and Compound [C] were used as crosslinking agents, the liquid crystal orientation was evaluated as A or B, and the electrical properties, film adhesion and storage stability were evaluated as S, A or B. In addition, the reprocessability was S or A, which was excellent. On the other hand, in Comparative Example 1 in which only Compound [B] was used as a crosslinking agent, the storage stability and reprocessability were evaluated as C. In Comparative Example 5 in which only Compound [C] was used as a crosslinking agent, the liquid crystal orientation and reprocessability were evaluated as C. Comparative Example 3 in which Compound [B] and another crosslinking agent were used as a crosslinking agent, and Comparative Examples 2 and 4 in which Compound [C] and another crosslinking agent were used as a crosslinking agent, all were evaluated as C in terms of storage stability.

[0337] [Example 11]

[0338] The formulation composition was changed to that shown in Table 4. Except for this, a liquid crystal alignment agent (AL-11) was prepared with the same solvent composition and solid content concentration as in Example 1. In addition, the liquid crystal alignment agent (AL-11) was used to evaluate the storage stability, film adhesion and reprocessability in the same manner as in Example 1, and a PSA type liquid crystal display element was manufactured to evaluate the liquid crystal orientation and voltage holding ratio. The evaluation results are shown in Table 4 together with the results of Comparative Example 1.

[0339] [Example 12]

[0340] The formulation composition was changed to that shown in Table 4. Except for this, a liquid crystal alignment agent (AL-12) was prepared with the same solvent composition and solid content concentration as in Example 1. In addition, the liquid crystal alignment agent (AL-12) was used to evaluate the storage stability, film adhesion and reprocessability in the same manner as in Example 1, and an FFS type liquid crystal display element was manufactured in the same manner as in Example 7 to evaluate the liquid crystal orientation and voltage holding ratio. The evaluation results are shown in Table 4 together with the results of Comparative Example 4.

[0341] [Table 4]

[0342]

[0343] As shown in Table 4, the liquid crystal orientation, electrical properties, film adhesion, storage stability and reprocessability of Examples 11 and 12, which used Compound [B] and Compound [C] as crosslinking agents, were evaluated as S or A. When the results were compared with the comparative examples (Comparative Example 1 and Comparative Example 4) having the same driving mode, respectively, in Example 11, the storage stability and reprocessability were particularly improved, and in Example 12, the storage stability was particularly improved.

[0344] The above results clearly show that the liquid crystal aligning agent containing the polymer component and the compound [B] and the compound [C] as crosslinking agents has excellent storage stability and can form a liquid crystal aligning film with good reprocessability, liquid crystal orientation and electrical properties. In addition, the alignment film formed by the liquid crystal aligning agent has sufficiently high adhesion to the substrate.

Claims

1. A liquid crystal alignment agent comprising the following components (A), (B) and (C): (A) a polymer selected from at least one of the group consisting of polyamic acid, polyamic acid ester, polyimide, polyorganosiloxane, and a polymer having a structural unit derived from a monomer having a carbon-carbon unsaturated bond; The component (B) is at least one selected from formula (b1) to formula (b13); The component (C) is at least one selected from formula (c1) to formula (c15), In formula (c1), formula (c2) and formula (c4), R 7 is a protecting group; R 11 , R 12 and R 13 One of them is a methyl group, and the rest are hydrogen atoms; R 14 , R 15 and R 16 One of them is a methyl group, and the rest are hydrogen atoms; R 17 , R 18 and R 19 One of them is a methyl group and the rest are hydrogen atoms. The content of the component (B) is 1 part by mass or more and 20 parts by mass or less, and the content of the component (C) is 1 part by mass or more and 20 parts by mass or less, based on 100 parts by mass of the total amount of the component (A). 2 . A liquid crystal alignment film formed using the liquid crystal alignment agent according to claim 1 . 3 . A method for manufacturing a liquid crystal alignment film, comprising coating the liquid crystal alignment agent according to claim 1 on a substrate, and irradiating the substrate with light after coating to impart liquid crystal alignment capability. 4 . A liquid crystal element, comprising the liquid crystal alignment film according to claim 2 .

5. A method for manufacturing a liquid crystal element, comprising: The step of applying the liquid crystal alignment agent according to claim 1 onto the conductive film of each of a pair of substrates having a conductive film to form a coating film; The step of configuring a pair of substrates coated with the liquid crystal alignment agent so that the coating films sandwich the liquid crystal layer and face each other to construct a liquid crystal unit; as well as A step of irradiating the liquid crystal cell with light while a voltage is applied between the conductive films.

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