Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal element

Abstract

To provide a liquid crystal aligning agent capable of quickly relaxing accumulated charges and obtaining a liquid crystal alignment film excellent in seal adhesion, impurity resistance, and high-temperature backlight reliability. 【Solution means】The liquid crystal aligning agent contains a polymer component and a compound [A] which is at least one selected from the group consisting of a compound represented by formula (1) and a compound represented by formula (2). In formula (1) and formula (2), Y 11 and Y 21 are a carbon atom, a nitrogen atom, etc. X 11 and X 21 are divalent linking groups. R 11 and R 21 are nitrogen-containing heterocyclic groups. X 12 is a divalent chain hydrocarbon group, etc. Y 12 in X 11 and R 12 is connected by a straight chain composed of 4 or more atoms connected by single bonds. R 12 is a protected amino group, etc. X 22 is a single bond or a divalent linking group. R 22 is a hydrogen atom or a monovalent organic group, and there are a plurality of R 22 , and at least one of the plurality of R 22 is a monovalent organic group. TIFF2026048039000031.tif40168

Description

[Technical Field]

[0001] This invention relates to a liquid crystal alignment agent, a liquid crystal alignment film, and a liquid crystal element. [Background technology]

[0002] In recent years, liquid crystal elements have been applied to a wide range of applications, from relatively large display devices such as liquid crystal televisions and information displays to small display devices such as smartphones. With this diversification of applications for liquid crystal elements, there is a demand for further improvement in their quality, and for example, attempts are being made to rapidly alleviate the accumulated charge in the liquid crystal alignment film (see, for example, Patent Document 1).

[0003] Patent Document 1 discloses that, in order to improve the electrical properties of a liquid crystal alignment film, a polymer having a structure derived from a diamine having a carboxyl group and a polymer having a structure derived from a diamine having a tertiary nitrogen atom are included in the liquid crystal alignment agent. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2015-092222 [Overview of the project] [Problems that the invention aims to solve]

[0005] As applications expand, liquid crystal elements are expected to be used in more demanding environments than before. For example, the backlight may be shone on the liquid crystal panel for extended periods during continuous operation, or the liquid crystal panel may be used in high-temperature environments, requiring reliability against backlight irradiation in high-temperature environments (hereinafter also referred to as "high-temperature backlight reliability"). Furthermore, the use of liquid crystal elements in harsh environments can cause the liquid crystal alignment film to peel off from the sealing material interface, and if peeling occurs, there are concerns about a decrease in the display quality of the liquid crystal element.

[0006] On the other hand, with the increasing resolution of liquid crystal elements, the demands for quality have become even stricter. For example, high-resolution liquid crystal panels such as 4K and 8K are often equipped with insulating films. However, in liquid crystal panels equipped with insulating films, ionic impurities from the insulating film may leach into the liquid crystal through the liquid crystal alignment film. When ionic impurities leach into the liquid crystal, there are concerns that the quality of the liquid crystal elements may deteriorate, such as a decrease in voltage retention or an increase in accumulated charge. Therefore, the liquid crystal alignment film is required to have properties that suppress the penetration of impurities generated within the element into the liquid crystal, and that make it less likely to cause a deterioration in the quality of the liquid crystal elements due to impurities (hereinafter also referred to as "impurity resistance"). In order to meet the demands for even higher quality liquid crystal elements, it is necessary to satisfy multiple of these properties simultaneously.

[0007] The present invention has been made in view of the above problems, and its main objective is to provide a liquid crystal alignment agent that can quickly relieve accumulated charge and produce a liquid crystal alignment film with excellent seal adhesion, impurity resistance, and high-temperature backlight reliability. [Means for solving the problem]

[0008] According to the present invention, the following liquid crystal alignment agents, liquid crystal alignment films, and liquid crystal elements are provided.

[0009] [1] A liquid crystal alignment agent comprising a polymer component and a compound [A] selected from the group consisting of compounds represented by the following formula (1) and compounds represented by the following formula (2). [ka] (In formula (1), Y 11 X is a group obtained by removing (m+n+p) hydrogen atoms from a carbon atom, a nitrogen atom, or a substituted or unsubstituted aromatic or non-aromatic ring portion. 11 R is a divalent linking group. 11 X is a nitrogen-containing heterocyclic group. 12is a substituted or unsubstituted divalent chain hydrocarbon group, or a group in which some methylene groups in a substituted or unsubstituted divalent chain hydrocarbon group are replaced by -O-, -S-, -CO-, -CO-O-, -CO-NR 1 -, -CO-S- or -NR 1 -. R 1 is a hydrogen atom or a monovalent organic group. However, the straight chain connecting Y 12 and R 11 in X 12 is composed of 4 or more atoms connected by single bonds. R 12 is a protected amino group, (meth)acryloyl group, vinylphenyl group, maleimide group, vinyl group, oxiranyl group or oxetanyl group. R 13 is a monovalent organic group different from -X 11 -R 11 and -X 12 -R 12 . m and n are each independently an integer of 1 or more. p is an integer of 0 or more. When m is 2 or more, a plurality of R 11 and a plurality of X 11 are the same as or different from each other. When n is 2 or more, a plurality of R 12 and a plurality of X 12 are the same as or different from each other. When n is 1, at least one of X 12 and R 13 has a protected amino group, (meth)acryloyl group, vinylphenyl group, maleimide group, vinyl group, oxiranyl group or oxetanyl group. When Y 11 is a carbon atom, (m + n + p) is 4, and when Y 11 is a nitrogen atom, (m + n + p) is 3.) [Chemical formula] (In formula (2), Y 21 is a group obtained by removing (r + s + u) hydrogen atoms from a carbon atom, nitrogen atom, or ring moiety of a substituted or unsubstituted aromatic ring or non-aromatic ring. X 21 is a divalent linking group. R 21 is a nitrogen-containing heterocyclic group. X 22R is a single bond or a divalent linking group. 22 R is a hydrogen atom or a monovalent organic group. 23 is either a hydrogen atom or a monovalent organic group that does not have a bridging group. r and s are each independently integers of 1 or greater. t is an integer between 1 and 4. u is an integer of 0 or greater. However, s and t cannot be 1 at the same time; multiple R 22 At least one of them is a monovalent organic group. If r is 2 or more, multiple R 21 and multiple X 21 They are either identical or different from each other. If s is 2 or more, there are multiple X 22 They are either identical or different from each other. 21 When it is a carbon atom, (r+s+u) is 4, and Y 21 When it is a nitrogen atom, (r+s+u) is 3.

[0010] [2] A liquid crystal alignment film formed using the liquid crystal alignment agent described in [1] above. [3] A liquid crystal element comprising the liquid crystal alignment film described in [2] above. [Effects of the Invention]

[0011] According to the liquid crystal alignment agent of the present invention, it is possible to obtain a liquid crystal alignment film that can quickly relieve accumulated charge and has excellent seal adhesion, impurity resistance, and high-temperature backlight reliability. [Modes for carrying out the invention]

[0012] Liquid crystal alignment agent The liquid crystal alignment agent of this disclosure contains a polymer component and a compound (hereinafter also referred to as "compound [A]") which is at least one compound selected from the group consisting of the compound represented by formula (1) and the compound represented by formula (2). The components contained in the liquid crystal alignment agent of this disclosure, and other components that may be optionally added as needed, are described below. Unless otherwise specified, each component may be used alone or in combination of two or more. In this specification, numerical ranges indicated using "~" include the values ​​indicated before and after "~" as the lower and upper limits, respectively.

[0013] Herein, in this specification, "hydrocarbon group" means a group of hydrocarbons including linear hydrocarbon groups, alicyclic hydrocarbon groups, and aromatic hydrocarbon groups. "Linear hydrocarbon group" means a linear hydrocarbon group or a branched hydrocarbon group that does not contain a cyclic structure and consists only of a linear structure. However, linear hydrocarbon groups may be saturated or unsaturated. "Alicyclic hydrocarbon group" means a hydrocarbon group that contains only the structure of an alicyclic hydrocarbon as its ring structure and does not contain an aromatic ring structure. However, an alicyclic hydrocarbon group does not have to consist only of the structure of an alicyclic hydrocarbon, and may also include a linear structure as part of it. "Aromatic hydrocarbon group" means a hydrocarbon group that contains an aromatic ring structure as its ring structure. However, an aromatic hydrocarbon group does not have to consist only of an aromatic ring structure, and may include a linear structure or an alicyclic hydrocarbon structure as part of it. "Aromatic ring" means an aromatic hydrocarbon ring and an aromatic heterocycle. "Organic group" means an atomic group obtained by removing any hydrogen atom from a carbon-containing compound (i.e., an organic compound).

[0014] The "main chain" of a polymer refers to the "trunk" portion of the polymer, which consists of the longest chain of atoms. This "trunk" portion may contain a ring structure. For example, "having a specific structure in the main chain" means that the specific structure constitutes a part of the main chain. "Side chains" refer to the parts of a polymer that branch off from the "trunk". "(meth)acrylic" is a term that encompasses "acrylic" and "methacrylic", "(meth)acrylate" is a term that encompasses "acrylate" and "methacrylate", and "(meth)acrylo" is a term that encompasses "acrylo" and "methacrylo".

[0015] <Polymer components> The polymer component contained in the liquid crystal alignment agent of this disclosure only needs to be crosslinked with compound [A], and its main skeleton is not particularly limited. Examples of polymer components include polymers having polyamic acid, polyamic acid ester, polyimide, polyorganosiloxane, polyester, polyamide, polyamideimide, polybenzoxazole precursor, polybenzoxazole, cellulose derivative, polyacetal, or addition polymer as the main skeleton and having functional groups that react (crosslink) with compound [A]. Addition polymers are polymers that contain structural units derived from monomers having polymerizable unsaturated carbon-carbon bonds, and examples include styrene polymers, (meth)acrylic polymers, maleimide polymers, (meth)acrylic-styrene copolymers, (meth)acrylic-maleimide copolymers, (meth)acrylic-styrene-maleimide copolymers, and styrene-maleimide copolymers.

[0016] As for the polymer component, it is preferable that it be at least one selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, polyamide, polyorganosiloxane, and addition polymer, in order to improve the liquid crystal alignment and voltage retention characteristics of the liquid crystal element. Among these, it is preferable to include a polymer (hereinafter also referred to as "polymer [P]") which is at least one selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, and polyamide, from the viewpoint of affinity with liquid crystal molecules, mechanical strength, and liquid crystal alignment.

[0017] The method for producing polyamic acid, polyamic acid esters, polyimides, and polyamides as polymers [P] is not particularly limited and can be produced by appropriately combining standard organic chemistry methods. The details of polyamic acid, polyamic acid esters, polyimides, and polyamides as polymers [P] will be described below.

[0018] [Polyamic acid] The polymer [P] in the present invention is a polyamic acid (hereinafter also referred to as "polyamic acid (P)") which is generally a polymer containing structural units derived from tetracarboxylic dianhydride and structural units derived from diamine. Polyamic acid (P) can be obtained, for example, by reacting tetracarboxylic dianhydride with a diamine.

[0019] (Tetracarboxylic acid dianhydride) Examples of tetracarboxylic dianhydrides used in the synthesis of polyamic acids (P) include aliphatic tetracarboxylic dianhydrides, alicyclic tetracarboxylic dianhydrides, and aromatic tetracarboxylic dianhydrides. Specific examples of these include, as aliphatic tetracarboxylic dianhydrides, 1,2,3,4-butanetetracarboxylic dianhydride; Examples of alicyclic tetracarboxylic dianhydrides include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-8-methyl-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione, and 3-oxabic Chlo[3.2.1]octane-2,4-dione-6-spiro-3'-(tetrahydrofuran-2',5'-dione), 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride, 3,5,6-tricarboxy-2-carboxymethylnorbornane-2:3,5:6-dianhydride, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride, 4,9-dioxatricyclo[5.3.1.02,6]undecane-3,5,8,10-tetraone, cyclohexanetetracarboxylic acid dianhydride, etc. Examples of aromatic tetracarboxylic dianhydrides include pyromellitic dianhydride, and the tetracarboxylic dianhydride described in Japanese Patent Publication No. 2010-97188 can also be used.

[0020] The tetracarboxylic dianhydride used in the synthesis preferably includes an alicyclic tetracarboxylic dianhydride, as this allows for high polymer solubility and the acquisition of a liquid crystal alignment film exhibiting good electrical properties. Among the alicyclic tetracarboxylic dianhydrides, it is preferable that the tetracarboxylic dianhydride includes 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-8-methyl-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride, and 1,2,3,4-cyclobutane It is preferable that the product contains at least one selected from the group consisting of tracarboxylic acid dianhydride and 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, and it is particularly preferable that the product contains at least one selected from the group consisting of 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, and 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride.

[0021] When the tetracarboxylic dianhydride includes at least one selected from the group consisting of 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, and 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, the total content of these compounds is preferably 10 mol% or more, and more preferably 20 to 100 mol%, relative to the total amount of tetracarboxylic dianhydride used in the synthesis of polyamic acid (P).

[0022] (Diamine) For the synthesis of polyamic acids (P), known diamines can be used, such as aliphatic diamines, alicyclic diamines, aromatic diamines, and diaminoorganosiloxanes. Specific examples of these diamines include, as aliphatic diamines, metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, and 1,3-bis(aminomethyl)cyclohexane; Examples of alicyclic diamines include 1,4-diaminocyclohexane and 4,4'-methylenebis(cyclohexylamine);

[0023] Examples of aromatic diamines include p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfide, 1,5-diaminonaphthalene, 2,2'-dimethyl-4,4'-diaminobiphenyl, 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl, 4,4'-diaminodiphenyl ether, 1,3-bis(4-aminophenoxy)propane, 9,9-bis(4-aminophenyl)fluorene, and 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluor Olopropane, 4,4'-(p-phenylenediisopropylidene)bisaniline, 1,4-bis(4-aminophenoxy)benzene, 2,6-diaminopyridine, 3,6-diaminocarbazole, N,N'-bis(4-aminophenyl)-benzidine, 1,4-bis-(4-aminophenyl)-piperazine, 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-inden-5-amine, 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-inden-6-amine Min, 3,5-diaminobenzoic acid, cholestanyloxy-3,5-diaminobenzene, cholestanyloxy-3,5-diaminobenzene, cholestanyloxy-2,4-diaminobenzene, cholestanyl 3,5-diaminobenzoate, cholestenyl 3,5-diaminobenzoate, lanostanyl 3,5-diaminobenzoate, 3,6-bis(4-aminobenzoyloxy)cholestane, 4-(4'-trifluoromethoxybenzoyloxy)cyclohexyl-3,5-diaminobenzoate, 1,1-bis(4-((aminophenyl (L)methyl)phenyl)-4-heptylcyclohexane, 1,1-bis(4-((aminophenyl)methyl)phenyl)-4-(4-heptylcyclohexyl)cyclohexane, 2,4-diamino-N,N-diallylaniline, 4-aminobenzylamine, N-[4-(2-aminoethyl)phenyl]benzene-1,4-diamine, N-[4-(aminomethyl)phenyl]benzene-1,4-diamine, (4-benzoylphenoxymethyl)benzene-1,3-diamine, cinnamic acid structure-containing diamines and the following formula (E-1), [ka] (In formula (E-1), X I and X II These are, independently, a single bond, -O-, *-COO-, or *-OCO- (where "*" represents a bond with the diaminophenyl group). I This is an alkanediyl group with 1 to 3 carbon atoms. II R is a single bond or an alkanediyl group having 1 to 3 carbon atoms. III (where a is an alkyl group, alkoxy group, fluoroalkyl group, or fluoroalkoxy group having 1 to 20 carbon atoms. a is 0 or 1. b is an integer between 0 and 3. c is an integer between 0 and 2. d is 0 or 1. However, 1 ≤ a + b + c ≤ 3.) Compounds represented by; Examples of diaminoorganosiloxanes include 1,3-bis(3-aminopropyl)-tetramethyldisiloxane, and diamines described in Japanese Patent Publication No. 2010-97188 can also be used.

[0024] Specific examples of compounds represented by the above formula (E-1) include, for example, the compounds represented by the following formulas (E-1-1) to (E-1-4). [ka]

[0025] The diamine used in the synthesis of polyamic acid (P) preferably contains aromatic diamines in an amount of 30 mol% or more, more preferably 50 mol% or more, and particularly preferably 80 mol% or more, relative to the total diamines.

[0026] (Synthesis of polyamic acids) Polyamic acid (P) can be obtained by reacting a tetracarboxylic dianhydride and a diamine as described above, together with a molecular weight modifier as needed. The ratio of tetracarboxylic dianhydride and diamine used in the synthesis reaction of polyamic acid (P) is preferably such that the acid anhydride groups of the tetracarboxylic dianhydride are in the proportion of 0.2 to 2 equivalents, and more preferably 0.3 to 1.2 equivalents, per 1 equivalent of the amino groups of the diamine.

[0027] Examples of molecular weight modifiers include acid monoanhydrides such as maleic anhydride, phthalic anhydride, and itaconic anhydride; monoamine compounds such as aniline, cyclohexylamine, and n-butylamine; and monoisocyanate compounds such as phenyl isocyanate and naphthyl isocyanate. The proportion of molecular weight modifier used is preferably 20 parts by mass or less, and more preferably 10 parts by mass or less, per 100 parts by mass of the total amount of tetracarboxylic dianhydride and diamine used.

[0028] The synthesis reaction of polyamic acid (P) is preferably carried out in an organic solvent. The reaction temperature is preferably -20°C to 150°C, and more preferably 0 to 100°C. The reaction time is preferably 0.1 to 24 hours, and more preferably 0.5 to 12 hours.

[0029] Examples of organic solvents used in the reaction include aprotic polar solvents, phenolic solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons, and hydrocarbons. Of these organic solvents, it is preferable to use one or more selected from the group consisting of aprotic polar solvents and phenolic solvents (organic solvents of group 1), or a mixture of one or more selected from organic solvents of group 1 and one or more selected from the group consisting of alcohols, ketones, esters, ethers, halogenated hydrocarbons, and hydrocarbons (organic solvents of group 2). In the latter case, the proportion of organic solvents of group 2 used is preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less, relative to the total amount of organic solvents of group 1 and group 2.

[0030] Particularly preferred organic solvents are one or more selected from the group consisting of N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide, m-cresol, xylenol, and halogenated phenol, or a mixture of one or more of these and other organic solvents within the above proportion range. The amount of organic solvent used (x) is preferably such that the total amount of tetracarboxylic dianhydride and diamine (y) is 0.1 to 50% by mass of the total amount of the reaction solution (x+y).

[0031] As described above, a reaction solution is obtained by dissolving polyamic acid (P). This reaction solution may be used as is for the preparation of the liquid crystal alignment agent, or the polyamic acid (P) contained in the reaction solution may be isolated and then used for the preparation of the liquid crystal alignment agent, or the isolated polyamic acid (P) may be purified and then used for the preparation of the liquid crystal alignment agent. When dehydrating and cyclizing the polyamic acid (P) to obtain polyimide, the above reaction solution may be used as is for the dehydration and cyclization reaction, or the polyamic acid (P) contained in the reaction solution may be isolated and then used for the dehydration and cyclization reaction, or the isolated polyamic acid (P) may be purified and then used for the dehydration and cyclization reaction. The isolation and purification of polyamic acid (P) can be carried out according to known methods.

[0032] [Polyamic acid ester] Polyamic acid esters as polymers [P] can be obtained, for example, by [I] reacting polyamic acid (P) obtained by the above synthesis reaction with an esterifying agent, [II] reacting tetracarboxylic acid diester with a diamine, [III] reacting tetracarboxylic acid dihalide with a diamine, etc. The polyamic acid ester to be contained in the liquid crystal alignment agent may have only an amic acid ester structure, or it may be a partially esterified product in which both an amic acid structure and an amic acid ester structure coexist. The reaction solution obtained by dissolving the polyamic acid ester may be used as is for the preparation of the liquid crystal alignment agent, or the polyamic acid ester contained in the reaction solution may be isolated and then used for the preparation of the liquid crystal alignment agent, or the isolated polyamic acid ester may be purified and then used for the preparation of the liquid crystal alignment agent. Isolation and purification of polyamic acid esters can be carried out according to known methods.

[0033] [Polyimide] Polyimides as polymers [P] can be obtained, for example, by dehydrating and cyclizing polyamic acid (P) synthesized as described above to form imidates.

[0034] The polyimide may be a fully imidized product obtained by dehydrating and cyclizing all of the amic acid structure present in its precursor, polyamic acid, or it may be a partially imidized product in which only a portion of the amic acid structure is dehydrated and cyclized, resulting in the coexistence of amic acid and imide ring structures. The polyimide contained in the liquid crystal alignment agent of this disclosure preferably has an imidization rate of 20% or more, more preferably 30-90%, and even more preferably 40-80%. This imidization rate is expressed as a percentage of the ratio of the number of imide ring structures to the total number of amic acid structures and imide ring structures in the polyimide. Here, a portion of the imide ring may be an isoimide ring.

[0035] Dehydration and ring closure of polyamic acid is preferably carried out by heating the polyamic acid, or by dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydration and ring closure catalyst to the solution, and heating as necessary.

[0036] In a method of adding a dehydrating agent and a dehydration ring-closing catalyst to a solution of polyamic acid, the dehydrating agent can be an acid anhydride such as acetic anhydride, propionic anhydride, or trifluoroacetic anhydride. The amount of dehydrating agent used is preferably 0.01 to 20 moles per mole of the amic acid structure of the polyamic acid. As the dehydration ring-closing catalyst, a tertiary amine such as pyridine, colidine, lutidine, triethylamine, or 1-methylpiperidine can be used. The amount of dehydration ring-closing catalyst used is preferably 0.01 to 10 moles per mole of the dehydrating agent used. Examples of organic solvents used in the dehydration ring-closing reaction include those exemplified as those used in the synthesis of polyamic acid. The reaction temperature for the dehydration ring-closing reaction is preferably 0 to 180°C, more preferably 10 to 150°C. The reaction time is preferably 1.0 to 120 hours, more preferably 2.0 to 30 hours.

[0037] In this way, a reaction solution containing polyimide is obtained. This reaction solution may be used as is for the preparation of the liquid crystal alignment agent, or the dehydrating agent and dehydration ring-closing catalyst may be removed from the reaction solution before preparing the liquid crystal alignment agent, or the polyimide may be isolated before preparing the liquid crystal alignment agent, or the isolated polyimide may be purified before preparing the liquid crystal alignment agent. These purification operations can be carried out according to known methods. In addition, polyimide can also be obtained by imidization of polyamic acid esters.

[0038] [polyamide] Polyamides as polymers [P] can be obtained, for example, by polycondensation reactions of dicarboxylic acids and diamines. Examples of diamines used in the reaction include those exemplified in the description of polyamic acids (P). In addition, in order to increase the solubility of the polyamide in the above reaction, the primary amino group of the diamine may be protected with a protecting group such as a tert-butoxycarbonyl group (hereinafter also referred to as a "Boc group") before being subjected to the reaction with the dicarboxylic acid. The dicarboxylic acid is not particularly limited, and known dicarboxylic acids used in the synthesis of polyamides can be used. It is preferable to acid chloride the dicarboxylic acid using a suitable chlorinating agent such as thionyl chloride before being subjected to the reaction with the diamine.

[0039] Examples of dicarboxylic acids include linear dicarboxylic acids such as oxalic acid, malonic acid, dimethylmalonic acid, succinic acid, glutaric acid, adipic acid, 2-methyladipic acid, and fumaric acid; alicyclic dicarboxylic acids such as cyclobutanedicarboxylic acid, 1-cyclobutenedicarboxylic acid, and cyclohexanedicarboxylic acid; and aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, 5-methylisophthalic acid, 2,5-dimethylterephthalic acid, 4-carboxycinnamic acid, 3,3'-[4,4'-(methylenedi-p-phenylene)]dipropionic acid, and 4,4'-[4,4'-(oxydi-p-phenylene)]dibutyric acid.

[0040] The reaction between a dicarboxylic acid and a diamine can be carried out by known methods, preferably in an organic solvent in the presence of a base. The preferred ratio of dicarboxylic acid to diamine is 0.2 to 2 equivalents of carboxyl groups of the dicarboxylic acid per 1 equivalent of amino groups of the diamine. The reaction temperature is preferably 0 to 200°C, and the reaction time is preferably 0.5 to 48 hours. Suitable organic solvents include, for example, tetrahydrofuran, dioxane, toluene, chloroform, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, and N-methyl-2-pyrrolidone. Suitable bases include, for example, pyridine, triethylamine, and tertiary amines such as N-ethyl-N,N-diisopropylamine. The preferred ratio of base is 2 to 4 moles per mole of diamine. The solution obtained from the above reaction may be used directly for the preparation of a liquid crystal alignment agent, or the polyamide contained in the reaction solution may be isolated before use, or the isolated polyamide may be purified before use. These purification operations can be carried out according to known methods.

[0041] The polymer [P] obtained as described above preferably has a solution viscosity of 20 to 1,800 mPa·s when it is prepared as a 15% by mass solution, and more preferably has a solution viscosity of 50 to 1,500 mPa·s. The solution viscosity (mPa·s) of the polymer is the value measured at 25°C using an E-type rotational viscometer for a 15% by mass polymer solution prepared using a good solvent for the polymer (e.g., γ-butyrolactone, N-methyl-2-pyrrolidone, etc.).

[0042] The weight-average molecular weight (Mw) of polymer [P], measured by gel permeation chromatography (GPC), is preferably 1,000 to 500,000, and more preferably 2,000 to 300,000. Furthermore, for polymer [P], the molecular weight distribution (Mw / Mn), expressed as the ratio of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn) measured by GPC, is preferably 8 or less, and more preferably 6 or less. By having the Mw and Mw / Mn of polymer [P] within the above ranges, good liquid crystal alignment of the liquid crystal element can be ensured.

[0043] The polymer component included in the liquid crystal alignment agent may consist of polymer [P] alone. In this case, polymer [P] may include a first polymer and a second polymer having higher polarity than the first polymer. Furthermore, the liquid crystal alignment agent may also contain polymer [Q], which is different from polymer [P], along with polymer [P]. The main skeleton of polymer [Q] may be any one that is different from polymer [P] among those exemplified in the description of the polymer component above, and among them, it is preferable that it be one selected from the group consisting of polyorganosiloxanes and addition polymers.

[0044] Preferred embodiments of the polymer component contained in the liquid crystal alignment agent include the following (I) to (III). (I) Embodiments comprising two or more polymers [P] (II) A form comprising polymer [P] and polymer [Q], wherein polymer [Q] is a polyorganosiloxane. (III) A form comprising polymer [P] and polymer [Q], wherein polymer [Q] is an addition polymer.

[0045] [Polyorganosiloxane] The polyorganosiloxane as polymer [Q] can be any polymer having a siloxane skeleton. The method for synthesizing the polyorganosiloxane is not particularly limited and can be obtained, for example, by hydrolysis or hydrolysis-condensation of a hydrolyzable silane compound, preferably in the presence of a suitable organic solvent, water, and a catalyst.

[0046] Examples of hydrolyzable silane compounds used in the synthesis of polyorganosiloxanes include alkoxysilane compounds such as tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, trimethoxysilylpropyl succinic anhydride, dimethyldimethoxysilane, and dimethyldiethoxysilane; Nitrogen- and sulfur-containing alkoxysilane compounds such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, mercaptomethyltrimethoxysilane, mercaptomethyltriethoxysilane, 3-ureidopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and N-(3-cyclohexylamino)propyltrimethoxysilane; Epoxy group-containing silane compounds such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; Examples include unsaturated bond-containing alkoxysilane compounds such as 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 3-(meth)acryloxypropylmethyldiethoxysilane, vinyltrimethoxysilane, and p-styryltrimethoxysilane.

[0047] The above hydrolysis-condensation reaction is carried out by reacting one or more of the above-mentioned silane compounds with water, preferably in the presence of a suitable catalyst and an organic solvent. The amount of water used in the reaction is preferably 1 to 30 moles per mole of the total amount of silane compounds. Examples of catalysts include acids, alkali metal compounds, organic bases (e.g., triethylamine and tetramethylammonium hydroxide), titanium compounds, and zirconium compounds. The amount of catalyst used varies depending on the type of catalyst, reaction conditions such as temperature, etc., and should be set appropriately, but is preferably 0.01 to 3 times the total amount of silane compounds. Examples of organic solvents include hydrocarbons, ketones, esters, ethers, and alcohols, and it is preferable to use an organic solvent that is insoluble or poorly soluble in water. The amount of organic solvent used is preferably 10 to 10,000 parts by weight per 100 parts by weight of the total amount of silane compounds used in the reaction.

[0048] The above hydrolysis-condensation reaction is preferably carried out by heating, for example, in an oil bath. In this case, the heating temperature is preferably 130°C or lower, and the heating time is preferably 0.5 to 12 hours. After the reaction is complete, the polyorganosiloxane can be obtained by removing the solvent from the organic solvent layer separated from the reaction solution.

[0049] When applied to liquid crystal alignment agents for TN-type, STN-type, or vertically aligned liquid crystal display elements, specific groups such as liquid crystal alignment groups or groups having photo-aligning structures may be introduced into the side chains of the polyorganosiloxane. The method for synthesizing polyorganosiloxanes having these specific groups in their side chains is not particularly limited, but examples include synthesizing a polyorganosiloxane having epoxy groups by hydrolysis condensation of an epoxy group-containing silane compound, or a mixture of an epoxy group-containing silane compound and other silane compounds, and then reacting the obtained epoxy group-containing polyorganosiloxane with a carboxylic acid having the above-mentioned specific group. The reaction between the epoxy group-containing polyorganosiloxane and the carboxylic acid can be carried out according to known methods.

[0050] The polyorganosiloxane preferably has a weight-average molecular weight (Mw) in polystyrene equivalent, measured by GPC, in the range of 100 to 50,000, and more preferably in the range of 200 to 20,000. When the weight-average molecular weight of the polyorganosiloxane is within the above range, it is easy to handle when manufacturing the liquid crystal alignment film, and the resulting liquid crystal alignment film has sufficient material strength and properties.

[0051] [Addition polymer] The addition polymer [Q] can be any polymer obtained by a polymerization reaction of monomers having polymerizable unsaturated bonds, and is not particularly limited. Examples of monomers having polymerizable unsaturated bonds include compounds having (meth)acryloyl groups, vinyl groups, vinylphenyl groups, maleimide groups, etc. Furthermore, at least one selected from the group consisting of poly(meth)acrylates, maleimide polymers, and styrene-maleimide copolymers can be preferably used due to its ease of introducing functional groups and its good liquid crystal alignment properties.

[0052] Specific examples of monomers having polymerizable unsaturated bonds 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)acrylates, trimethoxysilylpropyl (meth)acrylates, 2-hydroxyethyl (meth)acrylates, glycidyl (meth)acrylates, 3,4-epoxycyclohexylmethyl (meth)acrylates, 3,4-epoxybutyl (meth)acrylates, and 4-hydroxybutyl glycidyl ether (meth)acrylates; and unsaturated polycarboxylic acid anhydrides such as maleic anhydride; and other (meth)acrylic compounds. 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; Examples include maleimide compounds such as N-methylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, 4-(2,5-dioxo-3-pyrrolin-1-yl)benzoic acid, N-(4-glycidyloxyphenyl)maleimide, N-glycidylmaleimide, 3-maleimidobenzoic acid, 3-maleimidopropionic acid, 3-(2,5-dioxo-3-pyrrolin-1-yl)benzoic acid, and methyl 4-(2,5-dioxo-3-pyrrolin-1-yl)benzoate. Furthermore, when the addition polymer is a polymer having a functional group, a compound having a functional group can be used as a monomer having a polymerizable unsaturated bond.

[0053] Addition polymers can be obtained, for example, by polymerizing monomers having polymerizable unsaturated bonds in the presence of a polymerization initiator. Preferred polymerization initiators include azo compounds such as 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), and 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile). The amount of polymerization initiator used is preferably 0.01 to 30 parts by mass per 100 parts by mass of the total monomer used in the reaction. The polymerization reaction is preferably carried out in an organic solvent. Examples of organic solvents used in the reaction include alcohols, ethers, ketones, amides, esters, and hydrocarbon compounds, with diethylene glycol ethyl methyl ether and propylene glycol monomethyl ether acetate being preferred. The reaction temperature is preferably 30°C to 120°C, and the reaction time is preferably 1 to 36 hours. The amount of organic solvent used (a) is preferably such that the total amount of monomers used in the reaction (b) is 0.1 to 60% by mass of the total amount of reaction solution (a + b). The addition polymer is preferably such that the weight-average molecular weight (Mw) of polystyrene equivalent, as measured by GPC, is 250 to 500,000, and more preferably 500 to 100,000.

[0054] In embodiments (II) and (III) above, when imparting liquid crystal alignment ability to an organic film formed using a liquid crystal alignment agent by a photo-alignment method, it is preferable to use a polymer having a photo-aligning group as at least one selected from the group consisting of polyorganosiloxanes and addition polymers, in which an alignment film with better liquid crystal alignment ability can be obtained.

[0055] The content of polymer [P] in the liquid crystal alignment agent of this disclosure is preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more, based on the total amount of solids contained in the liquid crystal alignment agent (components other than the solvent component of the liquid crystal alignment agent).

[0056] When polymer [Q] is included in the liquid crystal alignment agent, the content of polymer [Q] is preferably 50% by mass or less, and more preferably 40% by mass or less, based on the total amount of polymer components (i.e., the total amount of polymer [P] and polymer [Q]) contained in the liquid crystal alignment agent.

[0057] From the viewpoint of achieving sufficiently high film strength, the content ratio of polymer components in the liquid crystal alignment agent is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more, based on the total mass of solids contained in the liquid crystal alignment agent (total mass of components other than the solvent in the liquid crystal alignment agent).

[0058] <Compound [A]> Compound [A] is at least one selected from the group consisting of compounds represented by the following formula (1) and compounds represented by the following formula (2). [ka] (In formula (1), Y 11 X is a group obtained by removing (m+n+p) hydrogen atoms from a carbon atom, a nitrogen atom, or a substituted or unsubstituted aromatic or non-aromatic ring portion. 11 R is a divalent linking group. 11 X is a nitrogen-containing heterocyclic group. 12This is a substituted or unsubstituted divalent chain hydrocarbon group, or a portion of the methylene groups in a substituted or unsubstituted divalent chain hydrocarbon group is -O-, -S-, -CO-, -CO-O-, -CO-NR 1 -, -CO-S- or -NR 1 It is a divalent group replaced by -. R 1 is a hydrogen atom or a monovalent organic group. However, X 12 Y inside 11 and R 12 The linear chain connecting them is composed of four or more atoms linked by single bonds. 12 R is a protected amino group, (meth)acryloyl group, vinylphenyl group, maleimide group, vinyl group, oxyranyl group, or oxetanyl group. 13 is, -X 11 -R 11 and -X 12 -R 12 It is a different monovalent organic group. m and n are each independent integers of 1 or greater. p is an integer of 0 or greater. If m is 2 or greater, multiple R 11 and multiple X 11 They are either identical or different from each other. If n is 2 or more, there are multiple R 12 and multiple X 12 They are either identical or different from each other. When n is 1, X 12 and R 13 At least one of them has a protected amino group, a (meth)acryloyl group, a vinylphenyl group, a maleimide group, a vinyl group, an oxyranyl group, or an oxetanyl group. 11 When it is a carbon atom, (m+n+p) is 4, and Y 11 When the atom is nitrogen, (m+n+p) is 3. [ka] (In formula (2), Y 21 X is a group obtained by removing (r+s+u) hydrogen atoms from a carbon atom, a nitrogen atom, or the ring portion of a substituted or unsubstituted aromatic or non-aromatic ring. 21 R is a divalent linking group. 21 X is a nitrogen-containing heterocyclic group. 22R is a single bond or a divalent linking group. 22 R is a hydrogen atom or a monovalent organic group. 23 is either a hydrogen atom or a monovalent organic group that does not have a bridging group. r and s are each independently integers of 1 or greater. t is an integer between 1 and 4. u is an integer of 0 or greater. However, s and t cannot be 1 at the same time; multiple R 22 At least one of them is a monovalent organic group. If r is 2 or more, multiple R 21 and multiple X 21 They are either identical or different from each other. If s is 2 or more, there are multiple X 22 They are either identical or different from each other. 21 When it is a carbon atom, (r+s+u) is 4, and Y 21 When it is a nitrogen atom, (r+s+u) is 3.

[0059] [Compound represented by the above formula (1)] The compound represented by formula (1) above has a crosslinking group bonded to a linking group of a specific length and a nitrogen-containing heterocyclic group bonded to the linking group. In compounds with such a structure, the nitrogen-containing heterocyclic group of the compound is thought to influence the electrical properties within the device and capture impurities generated within the device, thereby rapidly easing accumulated charge in the liquid crystal alignment film and improving impurity resistance. Furthermore, the effect of such a nitrogen-containing heterocyclic group may not be fully obtained if a crosslinking group is present in the vicinity of the nitrogen-containing heterocyclic group. However, because the crosslinking group is bonded to a linking group of a specific length, a sufficient distance is ensured between the nitrogen-containing heterocyclic group and the crosslinking group, resulting in the full expression of the effect of the nitrogen-containing heterocyclic group. In addition, it is thought that the crosslinking structure formed by the compound represented by formula (1) leads to the formation of a liquid crystal alignment film with improved film strength and density, resulting in improved seal adhesion. Moreover, the improved film strength and density suppress film degradation in high-temperature environments, which is thought to improve high-temperature backlight reliability.

[0060] In the above equation (1), Y 11Examples of aromatic rings in a group obtained by removing (m+n+p) hydrogen atoms from the ring portion of a substituted or unsubstituted aromatic or non-aromatic ring represented by include aromatic hydrocarbon rings such as benzene rings, naphthalene rings, and anthracene rings, and aromatic heterocycles such as imidazole rings, pyridine rings, pyridazine rings, pyrazine rings, pyrimidine rings, thiophene rings, and furan rings; Examples of non-aromatic rings include aliphatic hydrocarbon rings such as cyclopentane rings and cyclohexane rings, and aliphatic heterocycles such as pyrrolidine rings, tetrahydrofuran rings, and piperidine rings. 11 Preferably, the group is obtained by removing (m+n+p) hydrogen atoms from a carbon atom, a nitrogen atom, or the ring portion of a substituted or unsubstituted aromatic ring, and more preferably, a group obtained by removing (m+n+p) hydrogen atoms from a carbon atom, a nitrogen atom, or a benzene ring or pyridine ring. Y 11 When the substituent is a group obtained by removing (m+n+p) hydrogen atoms from the ring portion of a substituted aromatic or non-aromatic ring, examples of substituents include halogen atoms, hydroxyl groups, C1-C6 alkyl groups, C1-C6 halogenated alkyl groups, C1-C6 alkoxy groups, and C1-C6 halogenated alkoxy groups.

[0061] X 11 Examples of divalent linking groups represented by include -O-, -CO-, -CO-O-, and -NR 2 -,-CO-NR 2 - A C1-C20 alkanediyl group, or a portion of the methylene group in a C2-C20 alkanediyl group, is -O-, -CO-, -CO-O-, -NR 2 -,-CO-NR 2 Examples include -, -S-, or divalent groups replaced by a divalent aromatic ring group. Among these, -O-, -CO-, -CO-O-, and -NR 2 -,-CO-NR 2 - A C1-C10 alkanediyl group, or a portion of the methylene group in a C2-C10 alkanediyl group, is -O-, -CO-, -CO-O-, -NR 2 -,-CO-NR 2-、-S-、 or a divalent group replaced by a divalent aromatic ring group is preferred. Further, from the viewpoint of more quickly relaxing the accumulated charge, an alkanediyl group having 3 to 10 carbon atoms, or some of the methylene groups in an alkanediyl group having 4 to 10 carbon atoms are -O-, -CO-, -CO-O-, -NR 2 -, -CO-NR 2 -, or a divalent group replaced by a divalent aromatic ring group is more preferred, and some of the methylene groups in an alkanediyl group having 5 to 10 carbon atoms, or an alkanediyl group having 6 to 10 carbon atoms are -O-, -CO-, -CO-O-, -NR 2 -, -CO-NR 2 -, or a divalent group replaced by a divalent aromatic ring group is even more preferred.

[0062] R 2 is a hydrogen atom or a monovalent organic group. R 2 Examples of the monovalent organic group represented by include an alkyl group having 1 to 10 carbon atoms, a monovalent group in which some of the methylene groups in an alkyl group having 1 to 10 carbon atoms are replaced by -O-, or a group that desorbs by heat (hereinafter also referred to as a "thermally desorbable group") (preferably heating during film formation). R 2 Examples of the monovalent thermally desorbable group represented by include carbamate-based protecting groups, acyl-based protecting groups, amide-based protecting groups, imide-based protecting groups, sulfonamide-based protecting groups, and the like. Among these, a carbamate-based protecting group is preferred in terms of high desorbability by heat. Specific examples thereof include Boc group, methoxycarbonyl group, benzyloxycarbonyl group, 1,1-dimethyl-2-haloethyloxycarbonyl group, allyloxycarbonyl group, 2-(trimethylsilyl)ethyloxycarbonyl group, 9-fluorenylmethyloxycarbonyl group, allyloxycarbonyl group, and the like. Among these, particularly, the Boc group is preferred in terms of excellent desorbability by heat and the ability to reduce the residual amount in the film of the desorbed portion. R 2 is preferably a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a Boc group.

[0063] R 11The nitrogen-containing heterocyclic group represented by is a group obtained by removing one hydrogen atom from the ring portion of a substituted or unsubstituted nitrogen-containing heterocyclic ring. The nitrogen-containing heterocyclic ring can be any aromatic ring containing one or more nitrogen atoms in its ring skeleton, and may contain only nitrogen atoms as heteroatoms in its ring skeleton, or it may contain nitrogen atoms and heteroatoms other than nitrogen atoms (oxygen atoms, sulfur atoms, etc.). Examples of nitrogen-containing heterocyclic rings include pyrrole rings, pyrazole rings, pyrrolidine rings, pyridine rings, pyrazine rings, pyrimidine rings, pyridazine rings, piperidine rings, piperazine rings, morpholine rings, imidazole rings, imidazoline rings, imidazolidine rings, triazole rings, indole rings, indidine rings, purine rings, quinoline rings, acridine rings, phenazine rings, phenatroline rings, carbazole rings, oxazole rings, thiazole rings, oxadiazole rings, and thiadiazole rings. From the viewpoint of rapidly easing accumulated charge and improving impurity resistance, at least one selected from the group consisting of pyrrole ring, pyrazole ring, pyrrolidine ring, pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring, piperidine ring, piperazine ring, morpholine ring, imidazole ring, imidazoline ring, imidazolidine ring, triazole ring, indole ring, indidine ring, purine ring, quinoline ring, acridine ring, and phenazine ring is preferred, and at least one selected from the group consisting of pyridine ring, pyridazine ring, piperazine ring, pyrazole ring, and imidazole ring is more preferred. R 11 If it is a substituted nitrogen-containing heterocyclic group, the substituent is the above Y. 11 The description of substituents in the following context applies.

[0064] X 12 From the perspective of improving high-temperature backlight reliability and seal adhesion, the group is a linear alkanediyl group having 4 to 20 carbon atoms, or a linear alkanediyl group having 4 to 20 carbon atoms in which some of the methylene groups are -O-, -S-, -CO-, -CO-O-, -CO-NR 1 -, -CO-S- or -NR 1 A divalent group replaced by - is preferred. 1 Regarding the above R2 The explanation applies.

[0065] X 12 However, if the substituted divalent linear hydrocarbon group or a divalent group in which a methylene group of a substituted divalent linear hydrocarbon group is replaced with -O-, etc., the substituent is Y 11 In addition to the groups exemplified in the description of substituents in R, other examples include protected amino groups, (meth)acryloyl groups, vinylphenyl groups, maleimide groups, vinyl groups, oxyranyl groups, and oxetanyl groups. A "protected amino group" is a group that is eliminated by heat to produce an amino group. Examples of thermally eliminated groups include the above R. 2 The description of a monovalent thermally leaving group represented by applies. An "oxiranyl group" is a group obtained by removing one hydrogen atom from oxirane (ethylene oxide), or by removing one hydrogen atom from each of the two carbon atoms of oxirane, and also includes groups in which the other hydrogen atoms are substituted with substituents such as hydrocarbon groups.

[0066] In the above equation (1), "X 12 Y inside 11 and R 12 "A linear chain connecting Y" is 11 and R 12 This refers to a chain in which adjacent atoms are bonded together and lined up in a straight line, with atoms connected by single bonds to form a linear chain. 12 Y inside 11 and R 12 The number of atoms forming the linear chains that connect the two is preferably 5 or more, more preferably 6 or more, and even more preferably 7 or more, from the viewpoint of fully exhibiting the effect of the nitrogen-containing heterocyclic group, as well as from the viewpoint of improving high-temperature backlight reliability and seal adhesion. 12 Y inside 11 and R 12 The number of atoms that make up a straight chain connecting two atoms with single bonds is, for example, X 12 If the propane-1,3-diyl group is a group in which the methylene groups at both ends are replaced by -NH- and -CO-O-, respectively, then Y 11 and R 12The number of atoms that make up the straight chain connecting and by single bonds is 4 (-NCCO-). Also, X 12 If Y is a divalent group in which the methylene groups at both ends of the butane-1,4-diyl group are replaced with -O- and -CO-NH-, respectively, 11 and R 12 The number of atoms that make up the linear chain connecting the two atoms, linked by single bonds, is 5 (-OCCCN-).

[0067] R 12 From the viewpoint of improving seal adhesion, protected amino groups, (meth)acryloyl groups, maleimide groups, oxyranyl groups, or oxetanyl groups are preferred.

[0068] R 13 -X 11 -R 11 and -X 12 -R 12 Examples of monovalent organic groups different from the above include substituted or unsubstituted monovalent linear hydrocarbon groups, or monovalent groups in which some methylene groups in substituted or unsubstituted monovalent linear hydrocarbon groups are replaced with -O-. 13 It is preferable that the group is a monovalent group in which some of the methylene groups in a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, or a substituted or unsubstituted alkyl group having 2 to 5 carbon atoms are replaced with -O-. 13 -X 11 -R 11 and -X 12 -R 12 A substituent on a monovalent organic group different from the above X 12 The description of substituents in the following context applies.

[0069] m is preferably 1 or 2, more preferably 1. n is preferably an integer between 1 and 3, more preferably 2 or 3. p is preferably an integer between 0 and 2.

[0070] By incorporating the compound represented by formula (1) above as a crosslinking agent into the liquid crystal alignment agent, a liquid crystal alignment film can be obtained that can rapidly relieve accumulated charge and has good impurity resistance, high-temperature backlight reliability, and seal adhesion. The compound represented by formula (1) preferably has a total of two or more protected amino groups, (meth)acryloyl groups, vinylphenyl groups, maleimide groups, vinyl groups, oxyranyl groups, or oxetanyl groups in order to act as a crosslinking agent, more preferably a total of 2 to 12 groups, and particularly preferably a total of 2 to 10 groups.

[0071] Furthermore, from the viewpoint of further improving seal adhesion and high-temperature backlight reliability, n is 2 or greater, or n is 1 and p is 1 or greater, and R 13 It is preferable that it has a protected amino group, (meth)acryloyl group, vinylphenyl group, maleimide group, vinyl group, oxyranyl group, or oxetanyl group, and it is more preferable that n is 2 or more.

[0072] Specific examples of compounds represented by formula (1) above include the compounds represented by formulas (1-1) to (1-26) below. In the structural formulas, "Boc" represents a tert-butoxycarbonyl group (the same applies below). [ka] [ka] [ka] [ka] [ka]

[0073] [Compound represented by the above formula (2)] The compound represented by formula (2) above has an organic group introduced to at least one of its hydroxyl groups, resulting in reduced polarity, and is likely to be concentrated at the interface between the liquid crystal alignment film and the liquid crystal. As a result, the nitrogen-containing heterocyclic group of the compound affects the electrical properties within the device, and by capturing impurities generated within the device, the liquid crystal alignment film can quickly relieve accumulated charge and its impurity resistance is thought to be improved. Furthermore, the polymer components are crosslinked by the compound represented by formula (2), forming a liquid crystal alignment film with improved film strength and density, which is thought to improve seal adhesion. In addition, the improved film strength and density are thought to suppress film degradation in high-temperature environments, improving high-temperature backlight reliability.

[0074] In the above equation (2), Y 21 As for the above Y 11 The explanation applies by replacing (m+n+p) with (r+s+u).

[0075] X 22 Examples of divalent linking groups represented by include -O-, -CO-, -CO-O-, and -NR 4 -,-CO-NR 4 - A substituted or unsubstituted alkanediyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted alkanediyl group having 2 to 20 carbon atoms, where some of the methylene groups are -O-, -S-, -CO-, -CO-O-, -CO-NR 4 -, -CO-S- or -NR 4 A divalent group replaced by - is an example. X 22 These are single bonds, -CO-O-, and -CO-NR 4 - A substituted or unsubstituted alkanediyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted alkanediyl group having 2 to 10 carbon atoms, where some of the methylene groups are -O-, -CO-NR 4 -or-NR 4 A divalent group replaced with - is preferred. 4 Regarding the above R 2 The explanation applies.

[0076] In equation (2) above, R 22If is a monovalent organic group, then the -OR in formula (2) 22 It is preferable that is a monovalent thermally leaving group. Here, -OR 22 If it is a monovalent thermally leaving group, then it will be -OR by heat 22 By detaching, -OR 22 It is believed that the methylene group to which it is bonded becomes a benzyl cation, and that this benzyl cation undergoes a crosslinking reaction with the polymer.

[0077] -OR 22 If is a monovalent thermally leaving group, 22 Examples of monovalent organic groups represented by include alkyl groups, acetyl groups, benzoyl groups, benzyl groups, p-methoxyphenylbenzyl groups, methoxymethyl groups, 1-ethoxyethyl groups, Boc groups, trimethylsilyl groups, triethylsilyl groups, 2-tetrahydropyranyl groups, tert-butyldimethylsilyl groups, trityl groups, etc. 22 Among these, the depolarization of the compound represented by formula (2) above, and -OR 22 From the viewpoint of ensuring a balance with the leaving properties, alkyl groups having 1 to 7 carbon atoms are preferred, alkyl groups having 1 to 3 carbon atoms are more preferred, and methyl groups are even more preferred.

[0078] Multiple R in equation (2) above 22 From the viewpoint of making the compound represented by formula (2) above more likely to be unevenly distributed at the interface between the liquid crystal alignment film and the liquid crystal, multiple R 22 Preferably, is a monovalent organic group, and multiple R 22 It is more preferable that all of them are monovalent organic groups.

[0079] R 23 Examples of monovalent organic groups that do not have a crosslinking group, as represented by R, include alkyl groups having 1 to 5 carbon atoms. 23 The hydrogen atom or an alkyl group having 1 to 3 carbon atoms is preferred, and a hydrogen atom or a methyl group is more preferred.

[0080] X 21 Regarding the above X 11 The explanation applies. 21 Regarding the above R11 The explanation applies. r is preferably 1 or 2, more preferably 1. s is preferably an integer between 1 and 3, more preferably 2 or 3. t is preferably an integer between 2 and 4, more preferably 2 or 3. u is preferably an integer between 0 and 2, more preferably 0 or 1.

[0081] By incorporating the compound represented by formula (2) above as a crosslinking agent into the liquid crystal alignment agent, it is possible to obtain a liquid crystal alignment film that can rapidly relieve accumulated charge and has good impurity resistance, high-temperature backlight reliability, and seal adhesion. The compound represented by formula (2) acts as a crosslinking agent by having the group "*-CH2-OR 22 It is preferable to have two or more of these (where "*" represents a bond with a benzene ring) in one molecule, more preferably 2 to 12, and particularly preferable 2 to 10.

[0082] Specific examples of compounds represented by formula (2) above include, for example, the compounds represented by formulas (2-1) to (2-4) below. [ka]

[0083] In the liquid crystal alignment agent of this disclosure, the content of compound [A] is preferably 1 part by mass or more, more preferably 2 parts by mass or more, even more preferably 3 parts by mass or more, and particularly preferably 5 parts by mass or more, based on 100 parts by mass of the total amount of polymer components contained in the liquid crystal alignment agent. Furthermore, the content of compound [A] is preferably 20 parts by mass or less, even more preferably 15 parts by mass or less, and particularly preferably 10 parts by mass or less.

[0084] <Other ingredients> The liquid crystal alignment agent may contain polymer components and compound [A], as well as other components as needed. Examples of other components include solvents, crosslinking agents different from compound [A] (hereinafter also referred to as "compound [B]"), antioxidants, metal chelating compounds, curing accelerators, surfactants, fillers, dispersants, and photosensitizers. The proportion of other components can be appropriately selected depending on each compound, as long as it does not impair the effects of the present invention.

[0085] [solvent] The liquid crystal alignment agent of this disclosure is preferably prepared as a liquid composition in which a polymer component, compound [A], and optionally added components are dissolved in a solvent. The solvent is preferably an organic solvent, such as aprotic polar solvents, phenolic solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons, hydrocarbons, etc. Specific examples of organic solvents used include, for example, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 1,2-dimethyl-2-imidazolidinone, 1,3-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-i-propyl ether, and Examples include 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, isoamyl propionate, isoamyl isobutyrate, diisopentyl ether, ethylene carbonate, propylene carbonate, cyclohexanone, diisobutyl ketone, and 3-methoxy-1-butanol.

[0086] [Compound [B]] Compound [B] includes oxyranyl groups, oxetanyl groups, cyclic thioether groups, cyclic carbonate groups, hydroxyl groups, protected hydroxyl groups, methylol groups, protected methylol groups, mercapto groups, protected mercapto groups, amino groups, protected amino groups, isocyanate groups, protected isocyanate groups, alkoxysilyl groups, polymerizable carbon-carbon unsaturated bond groups (alkenyl groups, vinyl ether groups, vinylphenyl groups, maleimide groups, (meth)acryloyl groups, etc.), β-hydroxyalkylamide groups, β-alkoxyalkylamide groups, oxazoline groups, aldehyde groups, carbodiimide groups, carboxyl groups, protected carboxyl groups, and the group "-CR". 50 =CR51 -R 52 -" However, R 50 R is a monovalent organic group that is eliminated by reaction with an amino group. 51 R is a hydrogen atom or an alkyl group. 52 Compound [B] is an electron-withdrawing group. Compound [B] has a total of two or more crosslinking groups selected from the group consisting of silanol groups and alkoxysilyl groups, and a different compound from compound [A] can be used. The number of crosslinking groups in compound [B] is more preferably 2 to 12 in total, and even more preferably 2 to 10 in total.

[0087] Specific examples of compound [B] include, for example, the compounds represented by formulas (c-1) to (c-19) below. [ka] [ka] (In formula (c-8), Ac represents an acetyl group.) [ka] (In equations (c-10) and (c-11), R 93 (This is a tert-butoxy group.) [ka]

[0088] When compound [B] is incorporated into the liquid crystal alignment agent of this disclosure, the content of compound [B] in the liquid crystal alignment agent is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, and even more preferably 2 parts by mass or more, based on 100 parts by mass of the total amount of polymer components contained in the liquid crystal alignment agent (i.e., the total amount of polymer [P] and polymer [Q]). Furthermore, the content of compound [B] is preferably 30 parts by mass or less, and more preferably 20 parts by mass or less, based on 100 parts by mass of the total amount of polymer components.

[0089] The solid content concentration in the liquid crystal alignment agent (the ratio of the total mass of components other than the solvent to the total mass of the liquid crystal alignment agent) is appropriately selected considering viscosity, volatility, etc., but is preferably in the range of 1 to 10% by mass. When the solid content concentration is 1% by mass or more, a sufficient film thickness can be ensured for the coating, and a liquid crystal alignment film exhibiting good liquid crystal alignment properties is easily obtained. On the other hand, when the solid content concentration is 10% by mass or less, the coating can be made of an appropriate thickness, a liquid crystal alignment film exhibiting good liquid crystal alignment properties is easily obtained, and the viscosity of the liquid crystal alignment agent tends to be appropriate, resulting in good coatability.

[0090] <Liquid crystal alignment films and liquid crystal elements> The liquid crystal alignment film of this disclosure is formed from a liquid crystal alignment agent prepared as described above. The liquid crystal element of this disclosure comprises 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 and can be applied to various modes such as TN type, STN type, VA type (including VA-MVA type, VA-PVA type, etc.), IPS (In-Plane Switching) type, FFS (Fringe Field Switching) type, OCB (Optically Compensated Bend) type, and PSA (Polymer Sustained Alignment) type. The liquid crystal element can be manufactured by a method including, for example, the following steps 1 to 3. In step 1, the substrate used differs depending on the desired operating mode. Steps 2 and 3 are common to each operating mode.

[0091] <Step 1: Formation of the coating> First, a liquid crystal alignment agent is applied to the substrate, and preferably the applied surface is heated to form a coating on the substrate. For example, transparent substrates made of glass such as float glass or soda glass, or resins such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, or poly(alicyclic olefin) can be used as the substrate. As the transparent conductive film provided on one surface of the substrate, NESA films (registered trademark of PPG, Inc., USA) made of tin oxide (SnO2), ITO films made of indium oxide-tin oxide (In2O3-SnO2), etc., can be used. When manufacturing TN, STN, or VA type liquid crystal elements, two substrates with patterned transparent conductive films are used. On the other hand, when manufacturing IPS or FFS type liquid crystal elements, a substrate with comb-shaped patterned electrodes and a counter substrate without electrodes are used. The liquid crystal alignment agent is applied to the substrate on the electrode formation surface, preferably by offset printing, flexographic printing, spin coating, roll coating, or inkjet printing.

[0092] After applying the liquid crystal alignment agent, preheating (pre-bake) is preferably performed to prevent dripping of the applied liquid crystal alignment agent. The pre-bake temperature is preferably 30 to 200°C, and the pre-bake time is preferably 0.25 to 10 minutes. Subsequently, a firing (post-bake) process is performed to further remove the solvent. The firing temperature (post-bake temperature) at this time is preferably 80 to 250°C, more preferably 80 to 200°C. The post-bake time is preferably 5 to 200 minutes. The film thickness of the film formed in this way is preferably 0.001 to 1 μm.

[0093] <Step 2: Orientation Treatment> When manufacturing TN, STN, IPS, or FFS type liquid crystal elements, a process (alignment treatment) is performed to impart liquid crystal alignment ability to the coating film formed in step 1 above. This imparts the liquid crystal molecule alignment ability to the coating film, making it a liquid crystal alignment film. As an alignment treatment, methods such as rubbing, in which the coating film formed on the substrate is rubbed in a certain direction with a roll wrapped with a cloth made of fibers such as nylon, rayon, or cotton, or photo-alignment, in which light is irradiated onto the coating film formed on the substrate to impart liquid crystal alignment ability to the coating film, can be used. On the other hand, when manufacturing vertical alignment (VA) type liquid crystal elements, the coating film formed in step 1 above can be used as is as a liquid crystal alignment film, but an alignment treatment may be applied to the coating film to further enhance its liquid crystal alignment ability. A liquid crystal alignment film suitable for vertical alignment type liquid crystal elements is also suitable for PSA type liquid crystal elements.

[0094] In the photo-alignment process, light irradiation can be performed by methods such as irradiating the coating film after the post-bake process, irradiating the coating film after the pre-bake process but before the post-bake process, or irradiating the coating film while it is being heated in at least one of the pre-bake or post-bake processes. As radiation to irradiate the coating film, for example, ultraviolet light and visible light including light with wavelengths of 150 to 800 nm can be used. Preferably, ultraviolet light including light with wavelengths of 200 to 400 nm is used. If the radiation is polarized, it may be linearly polarized or partially polarized. If the radiation used is linearly polarized or partially polarized, irradiation may be performed from a direction perpendicular to the substrate surface, from an oblique direction, or a combination of these. In the case of unpolarized radiation, the irradiation direction should be oblique.

[0095] Examples of light sources that can be used include low-pressure mercury lamps, high-pressure mercury lamps, deuterium lamps, metal halide lamps, argon resonance lamps, xenon lamps, and excimer lasers. The radiation dose to the substrate surface is preferably 400 to 50,000 J / m². 2 And more preferably 1,000 to 20,000 J / m 2In addition, after light irradiation to impart orientation ability, the substrate surface may be washed with, for example, water, an organic solvent (e.g., methanol, isopropyl alcohol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, etc.), or a mixture thereof, or the substrate may be heated.

[0096] <Step 3: Liquid Crystal Cell Construction> Two substrates with liquid crystal alignment films formed on them as described above are prepared, and a liquid crystal cell is manufactured between the two substrates so that liquid crystal is arranged adjacent to the liquid crystal alignment film. To manufacture the liquid crystal cell, for example, two substrates are placed opposite each other with a gap in between so that the liquid crystal alignment films face each other, the periphery of the two substrates is bonded together with a sealant, and liquid crystal is injected and filled into the cell gap surrounded by the substrate surface and the sealant, sealing the injection hole, or an ODF method can be used. As the sealant, for example, an epoxy resin containing a curing agent and aluminum oxide spheres as spacers can be used. As the liquid crystal, nematic liquid crystal and smectic liquid crystal can be used, and among these, nematic liquid crystal is preferred. In PSA mode, after the construction of the liquid crystal cell, a voltage is applied between the conductive films of the pair of substrates, and the liquid crystal cell is irradiated with light.

[0097] PSA-type liquid crystal elements can be manufactured by a method that includes the following steps. A step of forming a coating film by applying the liquid crystal alignment agent of this disclosure onto the conductive film of each of a pair of substrates having a conductive film. A process for constructing a liquid crystal cell by arranging a pair of substrates coated with a liquid crystal alignment agent so that the coating films face each other with a liquid crystal layer in between. • A process of applying a voltage between conductive films and irradiating a liquid crystal cell with light.

[0098] Specifically, a liquid crystal cell is constructed in the same manner as in steps 1 to 3 above, except that a photopolymerizable monomer is injected or dropped together with the liquid crystal between a pair of substrates having a conductive film. Conventionally known compounds can be used as the photopolymerizable monomer injected or dropped together with the liquid crystal. Preferably, it is a polyfunctional (meth)acrylic monomer.

[0099] In the manufacturing of PSA-type liquid crystal elements, after constructing the liquid crystal cell, a voltage is applied between the conductive films of a pair of substrates, and the liquid crystal cell is irradiated with light. The applied voltage can be, for example, 5 to 50 V DC or AC. As the irradiated light, ultraviolet light and visible light including wavelengths of 150 to 800 nm can be used. Of these, ultraviolet light including wavelengths of 300 to 400 nm is preferred. As the light source for the irradiation 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. The amount of light irradiated is preferably 1,000 to 200,000 J / m 2 More preferably, 1,000 to 100,000 J / m 2 That is the case.

[0100] For each mode of liquid crystal cell, a polarizing plate is then attached to the outer surface of the liquid crystal cell as needed to form a liquid crystal element. Examples of polarizing plates include a polarizing plate made by sandwiching a polarizing film called an "H film," which is made by stretching and oriented polyvinyl alcohol while absorbing iodine, between cellulose acetate protective films, or a polarizing plate made of the H film itself.

[0101] The liquid crystal elements of this disclosure can be effectively applied to a variety of uses. Specifically, they can be used, for example, in various display devices such as watches, portable game consoles, word processors, notebook computers, car navigation systems, camcorders, PDAs, digital cameras, mobile phones, smartphones, various monitors, liquid crystal televisions, information displays, as well as in dimming devices, phase difference films, and the like.

[0102] According to this disclosure, the following means are provided: [Method 1] A liquid crystal alignment agent comprising a polymer component and a compound [A] which is at least one compound selected from the group consisting of compounds represented by formula (1) and compounds represented by formula (2). [Method 2] Either n in formula (1) above is 2 or greater, or n is 1, p is 1 or greater, and R13 The liquid crystal aligning agent according to [Method 1], having a protected amino group, (meth)acryloyl group, vinylphenyl group, maleimide group, vinyl group, oxyranyl group or oxetanyl group. [Method 3] X in formula (1) above 12 However, either it is a linear alkanediyl group having 4 to 20 carbon atoms, or some of the methylene groups in a linear alkanediyl group having 4 to 20 carbon atoms are -O-, -S-, -CO-, -CO-O-, -CO-NR 1 -, -CO-S- or -NR 1 A liquid crystal alignment agent according to [Method 1] or [Method 2], which is a divalent group replaced by -. [Method 4] -OR in formula (2) above 22 However, the liquid crystal alignment agent is a monovalent thermally desorbable group, as described in any of [Method 1] to [Method 3]. [Method 5] A liquid crystal alignment agent according to any one of [Method 1] to [Method 4], wherein the polymer component contains at least one polymer [P] selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, and polyamide. [Method 6] The liquid crystal alignment agent according to [Method 5], further comprising a polymer [Q] different from the polymer [P]. [Method 7] A liquid crystal alignment film formed with a liquid crystal alignment agent described in any of [Method 1] to [Method 6]. [Method 8] A liquid crystal element comprising the liquid crystal alignment film described in [Method 7]. [Examples]

[0103] The present invention will be described in detail below with reference to examples, but it is not limited to the following examples. In the examples and comparative examples, "parts" and "%" refer to mass unless otherwise specified.

[0104] In the following example, the imidization rate of the polyimide, the weight-average molecular weight (Mw), the number-average molecular weight (Mn), and the epoxy equivalent of the polymer were measured by the following method. <Imidification rate of polyimides> A polyimide solution was added to pure water, and the resulting precipitate was thoroughly dried under reduced pressure at room temperature. Then it was dissolved in deuterated dimethyl sulfoxide, with tetramethylsilane as the reference substance, at room temperature. 1 1H-NMR measurements were performed. 1 The imidization rate [%] was determined from the 1H-NMR spectrum using the following formula (1). Imidization rate [%] = (1 - (β 1 / ( β 2 ×α)))×100 …(1) (In formula (1), β 1 This represents the peak area originating from the proton of the NH group, appearing around a chemical shift of 10 ppm, and β 2 α represents the peak area derived from other protons, and α is the ratio of other protons to one proton of the NH group in the polymer precursor (polyamic acid).

[0105] <Weight-average molecular weight (Mw) and number-average molecular weight (Mn) of polymers> Mw and Mn were measured by gel permeation chromatography (GPC) under the following conditions. The molecular weight distribution (Mw / Mn) was calculated from the obtained Mw and Mn values. Equipment: Showa Denko Corporation's "GPC-101" GPC columns: Combining "GPC-KF-801", "GPC-KF-802", "GPC-KF-803", and "GPC-KF-804" manufactured by Shimadzu GLC Co., Ltd. Mobile phase: Tetrahydrofuran (THF) Column temperature: 40℃ Flow rate: 1.0mL / min Sample concentration: 1.0% by mass Sample injection volume: 100 μL Detector: Differential refractometer Standard material: Monodisperse polystyrene

[0106] <Epoxy equivalent> The measurement was performed using the hydrochloride-methyl ethyl ketone method described in JIS C 2105.

[0107] The abbreviations for the compounds are as follows. In the following, the compound represented by formula (X) may simply be referred to as "compound (X)".

[0108] <Tetracarboxylic acid dianhydride> [ka]

[0109] <Diamine> [ka] [ka]

[0110] <Reactive compounds and other monomers> [ka] [ka]

[0111] <Additives> [ka] [ka]

[0112] <Synthesis of polymers> 1. Synthesis of polyamic acids [Synthesis Example 1] 50 moles each of compound (C-1) and compound (C-3) as tetracarboxylic dianhydrides, and 20 moles each of compound (D-1), compound (D-4), and compound (D-6) as diamines were dissolved in N-methyl-2-pyrrolidone (NMP). The reaction was carried out at 60°C for 6 hours to obtain a solution containing 20% ​​by mass of polyamic acid (referred to as polymer (P-1)).

[0113] [Synthesis examples 2-5, 8, 9, 11-15, 18-20 and 23-26] The same procedure as in Synthesis Example 1 was carried out, except that the types and amounts of tetracarboxylic dianhydrides and diamines used were changed as shown in Table 1, to obtain polyamic acids (these were designated as polymers (P-2) to (P-5), (P-8), (P-9), (P-11) to (P-15), (P-18) to (P-20), and (P-23) to (P-26)).

[0114] 2. Synthesis of polyimides [Synthesis Example 6] 80 moles of compound (C-2) and 20 moles of compound (C-4) as tetracarboxylic dianhydrides, and 30 moles of compound (D-2), 20 moles of compound (D-4), 40 moles of compound (D-6), and 10 moles of compound (D-10) as diamines were dissolved in NMP, and the reaction was carried out at 60°C for 6 hours to obtain a solution containing 20% ​​by mass of polyamic acid. Next, NMP was added to the obtained polyamic acid solution to make a 10% by mass solution of polyamic acid, and pyridine and acetic anhydride were added to carry out a dehydration and cyclization reaction at 80°C for 4 hours. After the dehydration and cyclization reaction, the solvent in the system was replaced with fresh NMP to obtain a solution containing 15% by mass of polyimide (referred to as polymer (P-6)) with an imidization rate of approximately 60%.

[0115] [Synthesis examples 7, 10, 16, 17, 21 and 22] The same procedure as in Synthesis Example 6 was carried out, except that the types and amounts of tetracarboxylic dianhydride and diamine used were changed as shown in Table 1, to obtain polyimides with the imidization rates shown in Table 1 (these were designated as polymers (P-7), (P-10), (P-16), (P-17), (P-21), and (P-22)).

[0116] In Table 1, the values ​​for tetracarboxylic dianhydrides (C-1 to C-6) represent the molar ratio of each compound relative to 100 moles of the total amount of tetracarboxylic dianhydrides used in the synthesis of the polymer. The values ​​for diamines (D-1 to D-21) represent the molar ratio of each compound relative to 100 moles of the total amount of diamines used in the synthesis of the polymer.

[0117] [Table 1]

[0118] 3. Synthesis of polyorganosiloxanes [Synthesis Example 27] In a reaction vessel equipped with a stirrer, thermometer, dropping funnel, and reflux condenser, 100.0 g of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 500 g of methyl isobutyl ketone, and 10.0 g of triethylamine were charged and mixed at room temperature. Then, 100 g of deionized water was added dropwise from the dropping funnel over 30 minutes, and the reaction was carried out at 80°C for 6 hours with stirring under reflux. After the reaction was complete, the organic layer was removed and washed with a 0.2% by mass aqueous solution of ammonium nitrate until the water after washing was neutral. The solvent and water were then removed under reduced pressure to obtain a polyorganosiloxane containing epoxy groups (referred to as polymer (ESSQ-1)) as a viscous transparent liquid. The weight-average molecular weight (Mw) of the obtained polymer (ESSQ-1) was 3,500, and the epoxy equivalent was 180 g / mol. In a 200 mL three-necked flask, 10.0 g of polymer (ESSQ-1), 30.28 g of methyl isobutyl ketone as solvent, compound (S-4) as a modifying component (side-chain carboxylic acid) in an amount equivalent to 30 mol% of the total amount of epoxy groups in polymer (ESSQ-1), and 0.10 g of UCAT 18X ​​(trade name, manufactured by Sunapro) as catalyst were charged, and the reaction was carried out at 100 °C for 48 hours with stirring. After the reaction was complete, ethyl acetate was added to the reaction mixture, and the resulting solution was washed three times with water. The organic layer was dried using magnesium sulfate, and the solvent was removed by distillation to obtain a polyorganosiloxane having liquid crystal oriented groups (referred to as polymer (PS-1)). The weight-average molecular weight (Mw) of the obtained polymer (PS-1) was 8000.

[0119] [Synthesis Example 28] A polyorganosiloxane having liquid crystal-aligning groups (referred to as polymer (PS-2)) was obtained in the same manner as in Synthesis Example 27, except that the type and amount of side-chain carboxylic acid used in the reaction were changed as shown in Table 2.

[0120] In Table 2, the values ​​for side-chain carboxylic acids represent the ratio (side-chain modification rate, mol%) to the amount of epoxy groups in the polymer (ESSQ-1).

[0121] [Table 2]

[0122] 4. Synthesis of addition polymers [Synthesis Example 29] Under nitrogen, 20 moles of compound (MA-2), 40 moles of compound (MA-4), and 40 moles of compound (MA-5) as polymerization monomers, 4 moles of 2,2'-azobis(2,4-dimethylvaleronitrile) as a radical polymerization initiator, and NMP as a solvent were added to a 100 mL two-necked flask, and polymerization was carried out at 70°C for 6 hours. After reprecipitation in methanol, the precipitate was filtered and vacuum-dried at room temperature for 8 hours to obtain an addition polymer (referred to as polymer (PM-1)). The weight-average molecular weight (Mw) measured in polystyrene equivalent by GPC was 35000, and the molecular weight distribution (Mw / Mn) was 2.

[0123] [Synthesis Examples 30-32] Except for changing the type and amount of polymerization monomer used in the reaction as shown in Table 3, the addition polymers (referred to as polymers (PM-2) to polymers (PM-4)) were obtained in the same manner as in Synthesis Example 29.

[0124] In Table 3, the monomer values ​​represent the proportion (moles) of each compound relative to 100 moles of the total amount of monomer used in the synthesis.

[0125] [Table 3]

[0126] <Preparation and evaluation of liquid crystal alignment agents> [Example 1: Vertical Optical Liquid Crystal Display Element (UV2A)] 1. Preparation of liquid crystal alignment agent A solution containing 70 parts by mass of polymer (P-1) obtained in Synthesis Example 1, a solution containing 30 parts by weight of polymer (P-14) obtained in Synthesis Example 14, and 5 parts by mass of additive (A-2) were diluted with NMP and butyl cellosolve (BC) to prepare a solution with a solvent composition of NMP / BC = 50 / 50 (mass ratio) and a solid content concentration of 3.5% by mass. Liquid crystal alignment agent (AL-1) was prepared by filtering this solution through a pore size 0.2 μm filter.

[0127] 2. Preparation of insulating film forming composition 7 parts by mass of 2,2'-azobis(2,4-dimethylvaleronitrile), 200 parts by mass of propylene glycol monomethyl ether acetate, 15 parts by mass of methacrylic acid, 30 parts by mass of glycidyl methacrylate, 20 parts by mass of styrene, 5 parts by mass of 2-hydroxyethyl acrylate, and 30 parts by mass of isobornyl acrylate were charged into a flask equipped with a condenser and a stirrer. After purging with nitrogen, stirring was started slowly. The reaction solution was raised to 62°C and maintained at this temperature for 5 hours to obtain a polymer solution containing the acrylic copolymer (R-1). The obtained polymer solution was dropped to 900 parts by mass of hexane to precipitate the acrylic copolymer (R-1). The precipitated acrylic copolymer (R-1) was separated, 150 parts by mass of propylene glycol monomethyl ethyl acetate was added, and the mixture was heated to 40°C and distilled under reduced pressure to obtain a polymer solution containing the acrylic copolymer (R-1). The polymer solution containing the obtained acrylic copolymer (R-1) had a solid content concentration of 30% by mass. GPC analysis revealed that the area of ​​unreacted monomers and polymerization initiators was 2.3%, and the weight-average molecular weight (Mw) was 12800. For every 100 parts by mass (solid content) of acrylic copolymer (R-1), 25 parts by mass of a condensate of 4,4'-[1-[4-[1-[4-hydroxyphenyl]-1-methylethyl]phenyl]ethylidene]bisphenol (1.0 mol) and 1,2-naphthoquinone diazide-5-sulfonic acid chloride (2.0 mol) is added as a photosensitive agent, and a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate (manufactured by Nippon Kayaku Co., Ltd., "KAYARAD") is added as a polymerizable compound. 5 parts by mass of DPHA, 10 parts by mass of 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate (Kyowa Nol M, manufactured by Kyowa Hakko Kirin Co., Ltd.) as a film-forming aid, and SH28PA (manufactured by Toray Dow Corning Co., Ltd.) as a leveling agent were mixed and dissolved in diethylene glycol ethyl methyl ether to a solid content concentration of 18% by mass. The mixture was then filtered through a membrane filter with a pore size of 0.2 μm to prepare insulating film-forming composition (RD-1).

[0128] 3. Fabrication of a substrate with an insulating film The insulating film forming composition (RD-1) was applied to a glass substrate using a spin coater, and then pre-baked on a hot plate at 90°C for 2 minutes. Subsequently, exposure was performed using a proximity exposure machine (Canon's "MA-1200" (ghi-line mixed)) at a concentration of 300 mJ / cm². 2 After irradiating the entire substrate with light, it was heated in an oven at 230°C for 30 minutes (post-bake) to cure it, forming an insulating film with a thickness of 3 μm on the glass substrate.

[0129] 4. Manufacturing of liquid crystal cells for impurity resistance evaluation A liquid crystal alignment agent (AL-1) was applied using a spinner to the electrode formation surface of a substrate equipped with comb-shaped patterned ITO electrodes, and to the insulating film formation surface of a substrate equipped with an insulating film. The substrates were then pre-baked on a hot plate at 80°C for 1 minute. Subsequently, the substrates were heated at 230°C for 1 hour in an oven with nitrogen purging to create a pair (2 substrates) with a liquid crystal alignment film thickness of 0.1 μm. An epoxy resin adhesive containing 3.5 μm diameter aluminum oxide spheres was screen-printed onto the outer periphery of the surface of a substrate with an insulating film that had a liquid crystal alignment film. Then, the liquid crystal alignment film surfaces of a pair of substrates were pressed together, and the adhesive was heat-cured at 150°C for 1 hour. Next, negative liquid crystal (Merck MLC-6608) was filled into the gap between the substrates through the liquid crystal injection port, and the liquid crystal injection port was sealed with epoxy adhesive. Furthermore, to eliminate the flow orientation during liquid crystal injection, the mixture was heated to 130°C and then slowly cooled to room temperature to manufacture a liquid crystal cell.

[0130] 5. Manufacturing of liquid crystal cells for high-temperature backlight reliability and residual DC evaluation. A liquid crystal alignment agent (AL-1) was applied to the transparent electrode surface of a glass substrate with a transparent electrode made of ITO film using a spinner, and pre-baked on a hot plate at 80°C for 1 minute. Then, it was heated in an oven with nitrogen purging at 230°C for 1 hour to form a coating with a thickness of 0.1 μm. Next, the surface of this coating was exposed to polarized ultraviolet light containing a 313 nm emission line at 1,000 J / m² using an Hg-Xe lamp and a Gran-Taylor prism. 2 The substrate was irradiated from a direction tilted 40° from the substrate normal to impart liquid crystal alignment capability. The same operation was repeated to create a pair (2 substrates) of substrates with a liquid crystal alignment film. An epoxy resin adhesive containing 3.5 μm diameter aluminum oxide spheres was screen printed onto the outer periphery of one of the substrates having a liquid crystal alignment film. Then, the liquid crystal alignment film surfaces of the pair of substrates were placed facing each other, and they were pressed together so that the projection direction of the ultraviolet light axis of each substrate onto the substrate surface was opposite parallel. The adhesive was then heat-cured at 150°C for 1 hour. Next, negative liquid crystal (Merck MLC-6608) was filled into the gap between the substrates through the liquid crystal injection port, and the liquid crystal injection port was sealed with epoxy adhesive. Furthermore, to remove the flow orientation during liquid crystal injection, it was heated at 130°C and then slowly cooled to room temperature.

[0131] 6. Evaluation (1) Evaluation of impurity tolerance After the liquid crystal cells manufactured in step 4 above were left to stand in a 60°C oven, the voltage retention rate (VHR) was measured using the VHR-1 VHR measuring device manufactured by Toyo Technica Co., Ltd. under the conditions of 1V and 1670 milliseconds. A VHR higher than 70% was rated as "exceptionally good (◎)", between 70% and 60% was rated as "good (○)", between 45% and less than 60% was rated as "acceptable (△)", and less than 45% was rated as "poor (×)". As a result, the impurity resistance of this example was rated as "exceptionally good (◎)".

[0132] (2) Evaluation of high-temperature backlight reliability A voltage of 5V was applied to the liquid crystal cell manufactured in step 5 above for a duration of 60 microseconds and a span of 167 milliseconds. The voltage retention rate (VHR1) was measured 167 milliseconds after the voltage was removed. Next, the liquid crystal cell was left to stand in an 80°C oven under LED lamp illumination for 200 hours, and then allowed to cool naturally to room temperature. After cooling, a voltage of 5V was applied to the liquid crystal cell for a duration of 60 microseconds and a span of 167 milliseconds. The voltage retention rate (VHR2) was measured 167 milliseconds after the voltage was removed. The measuring device used was the "VHR-1" manufactured by Toyo Technica Co., Ltd. The rate of change of VHR (ΔVHR) at this time was calculated using the following formula (y), and the reliability of the liquid crystal alignment film was evaluated using ΔVHR. The evaluation was performed using the following criteria for reliability: ΔVHR of less than 1% was rated as "Excellent (◎)", 1% to less than 2% was rated as "Good (○)", 2% to less than 5% was rated as "Acceptable (△)", and 5% or more was rated as "Poor (×)". As a result, the high-temperature backlight reliability of this embodiment was rated as "Good (○)". ΔVHR[%]=(VHR1-VHR2) / (VHR1)×100 …(y)

[0133] (3) Evaluation of remaining DCs For the liquid crystal cells manufactured in step 5 above, a 30Hz / ±3V square wave with a 3V offset voltage was applied for 120 minutes at a temperature of 60°C. The residual DC voltage (V) remaining in the liquid crystal cells immediately after the 3V offset voltage was removed was measured using the flicker erasure method. A residual DC voltage of less than 0.4V was rated as "exceptionally good (◎)", 0.4V or more and less than 0.6V as "good reliability (○)", 0.6V or more and less than 1V as "acceptable (△)", and 1V or more as "poor reliability (×)". As a result, the residual DC in this example was rated as "exceptionally good (◎)".

[0134] (4) Evaluation of seal adhesion A liquid crystal alignment agent (AL-1) was applied to a glass substrate using a spinner, pre-baked on an 80°C hot plate for 2 minutes, and then heated in a 230°C oven with nitrogen purging for 30 minutes (post-bake) to form a coating (liquid crystal alignment film) with an average thickness of 0.10 μm. Two glass substrates with the coating were prepared by repeating the same procedure. On the coating of one glass substrate, an ODF sealant (Sekisui Chemical Co., Ltd., S-WB42) was applied to a width of 0.5 mm, and the other glass substrate was bonded so that the coating and the ODF sealant were in contact. Subsequently, a metal halide lamp was used to irradiate the substrate at 30,000 J / m². 2 After irradiating with light (equivalent to 365 nm), the sample was heated in a 120°C oven for 1 hour. Then, the seal adhesion was evaluated by measuring the adhesion force using an Imada Seisakusho tensile and compression testing machine (model number: SDWS-0201-100SL). The evaluation was based on an adhesion force of 180 N / cm². 2 If the result is above this, it is classified as "Excellent (◎)", 180 N / cm 2 Less than 170 N / cm 2 If the result is above this, it is marked as "Good (○)", 170 N / cm 2 Less than 150 N / cm 2 If the result is above this, it is marked as "Acceptable (△)", 150 N / cm 2 A result below this value was classified as "Poor (×)". As a result, the seal adhesion of this embodiment was evaluated as "Good (○)".

[0135] [Examples 2-5 and Comparative Example 1] Liquid crystal alignment agents (AL-2) to (AL-5) and (AR-1) were prepared with the same solvent composition and solid content concentration as in Example 1, except that the formulation composition was changed as shown in Table 4. Liquid crystal cells were manufactured using each liquid crystal alignment agent in the same manner as in Example 1, and impurity resistance, high-temperature backlight reliability, residual DC, and seal adhesion were evaluated. The evaluation results are shown in Table 4.

[0136] [Example 6: PSA-type liquid crystal display element] 1. Preparation of liquid crystal composition To 10 g of nematic liquid crystal (Merck MLC-6608 negative liquid crystal), 5% by mass of a liquid crystalline compound represented by the following formula (L1-1) and 0.3% by mass of a photopolymerizable compound represented by the following formula (L2-1) were added and mixed to obtain liquid crystal composition LC1. [ka]

[0137] 2. Preparation of liquid crystal alignment agent, and evaluation of impurity resistance and seal adhesion. Liquid crystal alignment agent (AL-6) was prepared by performing the same procedure as in Example 1, except that the composition of the liquid crystal alignment agent was changed as shown in Table 4. Furthermore, using the obtained liquid crystal alignment agent (AL-6), a liquid crystal cell for impurity resistance evaluation was manufactured in the same manner as in Example 1, except that liquid crystal composition LC1 was used as the liquid crystal composition, and the impurity resistance was evaluated. The seal adhesion was also evaluated using the liquid crystal alignment agent (AL-6). The results are shown in Table 4.

[0138] 3. Manufacturing of liquid crystal cells for high-temperature backlight reliability and residual DC evaluation. A liquid crystal alignment agent (AL-6) was applied to the transparent electrode surface of a glass substrate with a transparent electrode made of an ITO film using a spinner. After pre-baking on an 80°C hot plate for 1 minute, the solvent was removed by heating in a nitrogen-purged oven at 200°C for 1 hour, forming a coating film (liquid crystal alignment film) with a thickness of 0.08 μm. This coating film was then rubbed using a rubbing machine with a roll wrapped in rayon cloth at a roll rotation speed of 400 rpm, a stage movement speed of 3 cm / second, and a pile insertion length of 0.1 mm. Subsequently, ultrasonic cleaning was performed in ultrapure water for 1 minute, and then drying in a 100°C clean oven for 10 minutes to obtain a substrate with a liquid crystal alignment film. This operation was repeated to obtain a pair (2 sheets) of substrates with a liquid crystal alignment film. This rubbing process was a weak rubbing process performed to control the tilting of the liquid crystals and to perform alignment division in a simple manner. An epoxy resin adhesive containing aluminum oxide spheres with a diameter of 3.5 μm was screen printed onto the outer periphery of one of the substrates having a liquid crystal alignment film. Then, the liquid crystal alignment film surfaces of the pair of substrates were placed facing each other, overlapped, and pressed together. The adhesive was then heat-cured at 150°C for 1 hour. Next, the liquid crystal composition LC1 was filled into the gap between the substrates through the liquid crystal injection port, the liquid crystal injection port was sealed with an epoxy adhesive, and then, to remove the flow orientation during liquid crystal injection, it was heated at 150°C for 10 minutes and then slowly cooled to room temperature. Next, a 10V AC current with a frequency of 60Hz is applied between the electrodes of the obtained liquid crystal cell, and while the liquid crystal is in operation, ultraviolet light of 50,000 J / m² is irradiated using an ultraviolet irradiation device with a metal halide lamp as the light source. 2 The device was irradiated with the specified dose. This dose was measured using a light meter that measures at a wavelength of 365 nm. A PSA-type liquid crystal display element was manufactured using this method.

[0139] 4. Evaluation of high-temperature backlight reliability and residual DC The liquid crystal cells manufactured in step 3 above were evaluated for high-temperature backlight reliability and residual DC using the same method as in Example 1. The evaluation results are shown in Table 4.

[0140] [Examples 7-18, 21 and Comparative Examples 2-8] Liquid crystal alignment agents (AL-7) to (AL-18), (AL-21), and (AR-2) to (AR-8) were prepared with the same solvent composition and solid content concentration as in Example 6, except that the formulation composition was changed as shown in Table 4. Liquid crystal cells were manufactured using each liquid crystal alignment agent in the same manner as in Example 6, and impurity resistance, high-temperature backlight reliability, residual DC, and seal adhesion were evaluated. The evaluation results are shown in Table 4.

[0141] [Example 19: Optical FFS type liquid crystal display element] 1. Preparation of liquid crystal alignment agent, and evaluation of impurity resistance and seal adhesion. Liquid crystal alignment agent (AL-19) was prepared by performing the same procedure as in Example 1, except that the composition of the liquid crystal alignment agent was changed as shown in Table 4. Furthermore, a liquid crystal cell for impurity resistance evaluation was manufactured in the same manner as in Example 1, except that the obtained liquid crystal alignment agent (AL-19) was used, and the impurity resistance was evaluated. The seal adhesion was also evaluated using the liquid crystal alignment agent (AL-19). The results are shown in Table 4.

[0142] 2. Manufacturing of liquid crystal cells for high-temperature backlight reliability and residual DC evaluation. A glass substrate (referred to as the first substrate) was prepared, on which a flat electrode (bottom electrode), an insulating layer, and a comb-shaped electrode (top electrode) were laminated in that order on one side, and a glass substrate (referred to as the second substrate) without electrodes was prepared. Next, a liquid crystal alignment agent (AL-19) was applied to the electrode-forming surface of the first substrate and one substrate surface of the second substrate using a spinner, and heated on an 80°C hot plate for 1 minute (pre-bake). After that, it was dried in a 230°C oven with nitrogen purged for 30 minutes (post-bake) to form a coating film with an average thickness of 0.1 μm. The obtained coating film was exposed to 1,000 J / m of ultraviolet light containing linearly polarized 254 nm emission lines using an Hg-Xe lamp. 2 The substrate was irradiated from the direction normal to the substrate to perform photoalignment treatment. The irradiation dose was measured using a light meter that measures at a wavelength of 254 nm. Next, the photoaligned coating was heat-treated by heating it in a clean oven at 230°C for 30 minutes to form a liquid crystal alignment film. Next, for one of the pair of substrates on which the liquid crystal alignment film was formed, an epoxy resin adhesive containing aluminum oxide spheres with a diameter of 3.5 μm was applied by screen printing to the outer edge of the surface having the liquid crystal alignment film. Then, the substrates were overlapped and pressed so that the projection direction of the polarization axis onto the substrate surface during light irradiation was anti-parallel, and the adhesive was thermally cured at 150 °C for 1 hour. Next, a negative-type liquid crystal (manufactured by Merck, MLC-6608) was filled between the pair of substrates through the liquid crystal injection port, and then the liquid crystal injection port was sealed with an epoxy-based adhesive to obtain a liquid crystal cell. Further, in order to remove the flow alignment during liquid crystal injection, this was heated at 120 °C and then gradually cooled to room temperature.

[0143] 3. Evaluation of High-Temperature Backlight Reliability and Residual DC Regarding the liquid crystal cell manufactured in 2. above, the high-temperature backlight reliability and residual DC were evaluated in the same manner as in Example 1. The evaluation results are shown in Table 4.

[0144] [Example 20: Rubbing FFS-Type Liquid Crystal Display Element] 1. Preparation of Liquid Crystal Alignment Agent and Evaluation of Impurity Resistance and Seal Adhesion The same operations as in Example 1 were performed except that the composition of the liquid crystal alignment agent was changed as shown in Table 4, and a liquid crystal alignment agent (AL-20) was prepared. Also, a liquid crystal cell for impurity resistance evaluation was manufactured and the impurity resistance was evaluated in the same manner as in Example 1 except that the obtained liquid crystal alignment agent (AL-20) was used, and the seal adhesion was evaluated using the liquid crystal alignment agent (AL-20). The results are shown in Table 4.

[0145] 2. Manufacture of Liquid Crystal Cell for Evaluation of High-Temperature Backlight Reliability and Residual DC A glass substrate (referred to as the first substrate) with a flat electrode (bottom electrode), an insulating layer, and a comb-shaped electrode (top electrode) laminated in this order on one side, and a glass substrate without an electrode (referred to as the second substrate) were prepared. Next, a liquid crystal aligning agent (AL-20) was applied to each of the electrode formation surface of the first substrate and one side of the second substrate by a spinner and heated (pre-baked) on a hot plate at 110 °C for 3 minutes. Then, drying (post-baking) was performed in an oven at 230 °C with the inside of the oven replaced with nitrogen for 30 minutes to form a coating film with an average film thickness of 0.08 μm. Next, rubbing treatment was performed on the coating film surface with a rubbing machine having a roll wrapped with a rayon cloth at a roll rotation speed of 1000 rpm, a stage moving speed of 3 cm / sec, and a felt pressing length of 0.3 mm. Then, ultrasonic cleaning was performed in ultrapure water for 1 minute, and then drying was performed in a 100 °C clean oven for 10 minutes to obtain a pair of substrates having liquid crystal alignment films. Next, for a pair of substrates having liquid crystal alignment films, leaving a liquid crystal injection port at the edge of the surface on which the liquid crystal alignment film was formed, an epoxy resin adhesive containing aluminum oxide spheres with a diameter of 3.5 μm was screen printed and applied. Then, the substrates were overlapped and pressure bonded, and the adhesive was thermally cured at 150 °C for 1 hour. Next, a negative liquid crystal (manufactured by Merck, MLC-6608) was filled into the gap between the pair of substrates from the liquid crystal injection port, and then the liquid crystal injection port was sealed with an epoxy-based adhesive. Further, in order to remove the flow alignment during liquid crystal injection, it was heated at 120 °C and then gradually cooled to room temperature to manufacture a liquid crystal cell. When overlapping the pair of substrates, the rubbing methods of the respective substrates were made anti-parallel.

[0146] 3. Evaluation of High-Temperature Backlight Reliability and Residual DC Regarding the liquid crystal cell manufactured in 2. above, evaluation of high-temperature backlight reliability and residual DC was performed in the same manner as in Example 1. The evaluation results are shown in Table 4.

[0147] In Table 4, the parts of each component (polymer 1, polymer 2, additive 1, and additive 2) of the liquid crystal aligning agent represent the blending ratio (parts by mass) in terms of the solid content of each component with respect to the total amount of 100 parts by mass of the polymer components used in the preparation of the liquid crystal aligning agent.

[0148] [Table 4]

[0149] As shown in Table 4, the liquid crystal alignment agents of Examples 1 to 21 were evaluated as particularly good (◎) or good (○) in terms of impurity resistance, high-temperature backlight reliability, residual DC, and seal adhesion, demonstrating a good balance of various properties. In contrast, Comparative Examples 1, 2, and 4, which used only additives without nitrogen-containing heterocyclic groups, showed poor (×) evaluation of residual DC, and in particular, Comparative Examples 1 and 4 also showed poor (×) evaluation of impurity resistance. Furthermore, Comparative Examples 5 and 7, which used only additives with short linking groups that bond to the crosslinkable groups, showed poor (×) evaluation of residual DC or seal adhesion. In addition, Comparative Example 3, which did not contain any additives, and Comparative Example 8, which used only additives in which all methylol groups were not protected, showed poor (×) evaluation of seal adhesion. Furthermore, Comparative Example 6, which used additive (A-14) instead of compound [A], showed poor (×) evaluation of high-temperature backlight reliability and seal adhesion.

[0150] From the results above, it has become clear that the liquid crystal alignment agent of this disclosure can rapidly relieve accumulated charge and produce a liquid crystal element with excellent seal adhesion, impurity resistance, and high-temperature backlight reliability.

Claims

1. A liquid crystal alignment agent comprising a polymer component and a compound [A] selected from the group consisting of compounds represented by the following formula (1) and compounds represented by formula (2). 【Chemistry 1】 (In formula (1), Y １１ is a group obtained by removing (m + n + p) hydrogen atoms from a carbon atom, a nitrogen atom, or a ring portion of a substituted or unsubstituted aromatic or non-aromatic ring. X １１ is a divalent linking group. R １１ is a nitrogen-containing heterocyclic group. X １２ is a substituted or unsubstituted divalent chain hydrocarbon group, or a divalent group in which some methylene groups in a substituted or unsubstituted divalent chain hydrocarbon group are replaced by -O-, -S-, -CO-, -CO-O-, -CO-NR １ -, -CO-S- or -NR １ -. R １ is a hydrogen atom or a monovalent organic group. However, the straight chain connecting Y １２ in X １１ and R １２ is composed of 4 or more atoms connected by single bonds. R １２ is a protected amino group, (meth)acryloyl group, vinylphenyl group, maleimide group, vinyl group, oxiranyl group or oxetanyl group. R １３ is a monovalent organic group different from -X １１ -R １１ and -X １２ -R １２ . m and n are each independently an integer of 1 or more. p is an integer of 0 or more. When m is 2 or more, a plurality of R １１ and a plurality of X １１ are the same as or different from each other. If n is 2 or greater, multiple R １２ and multiple X １２ They are either identical or different from each other. When n is 1, X １２ and R １３ At least one of these has a protected amino group, a (meth)acryloyl group, a vinylphenyl group, a maleimide group, a vinyl group, an oxyranyl group, or an oxetanyl group. １１ When it is a carbon atom, (m+n+p) is 4, Y １１ When the atom is nitrogen, (m + n + p) is 3. 【Chemistry 2】 (In formula (2), Y ２１ This is a group obtained by removing (r + s + u) hydrogen atoms from a carbon atom, a nitrogen atom, or a substituted or unsubstituted aromatic or non-aromatic ring. ２１ R is a divalent linking group. ２１ X is a nitrogen-containing heterocyclic group. ２２ R is a single bond or a divalent linking group. ２２ R is a hydrogen atom or a monovalent organic group. ２３ is either a hydrogen atom or a monovalent organic group that does not have a bridging group. r and s are each independently integers of 1 or more. t is an integer from 1 to 4. u is an integer of 0 or more. However, s and t cannot be 1 at the same time, and there are multiple R ２２ At least one of them is a monovalent organic group. If r is 2 or more, multiple R ２１ and multiple X ２１ They are either identical or different from one another. If s is 2 or more, multiple X ２２ They are either identical or different from each other. ２１ When it is a carbon atom, (r + s + u) is 4, Y ２１ When it is a nitrogen atom, (r + s + u) is 3.

2. Either n in formula (1) above is 2 or greater, or n is 1, p is 1 or greater, and R １３ The liquid crystal aligning agent according to claim 1, wherein the aligning agent has a protected amino group, a (meth)acryloyl group, a vinylphenyl group, a maleimide group, a vinyl group, an oxyranyl group, or an oxetanyl group.

3. In the above equation (1) X １２ However, it is a linear alkanediyl group having 4 to 20 carbon atoms, or a part of the methylene group in a linear alkanediyl group having 4 to 20 carbon atoms is -O-, -S-, -CO-, -CO-O-, -CO-NR １ -, -CO-S- or -NR １ The liquid crystal alignment agent according to claim 1, wherein the divalent group is replaced by -.

4. -OR in formula (2) above ２２ The liquid crystal alignment agent according to claim 1, wherein the group is a monovalent thermally desorbable group.

5. The liquid crystal alignment agent according to claim 1, wherein the polymer component contains at least one polymer [P] selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, and polyamide.

6. Furthermore, the liquid crystal alignment agent according to claim 5, further comprising a polymer [Q] different from the polymer [P].

7. A liquid crystal alignment film formed with the liquid crystal alignment agent according to any one of claims 1 to 6.

8. A liquid crystal element comprising the liquid crystal alignment film described in claim 7.

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