Liquid crystal alignment agents, liquid crystal alignment films, liquid crystal elements, and thermosetting compositions

Abstract

To provide a liquid crystal aligning agent capable of producing a highly reliable liquid crystal element with good mechanical properties while maintaining good liquid crystal alignability.SOLUTION: A liquid crystal aligning agent provided herein contains a polymer (P) having a carboxy group, and a compound (C) having multiple groups represented by "-OX1" (where X1 is a hydrogen atom or thermally cleavable group) in a molecule, where one or more of the groups represented by "-OX1" are monovalent groups having tetrahydropyran ring structures or tetrahydrofuran ring structures.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a liquid crystal alignment agent, a liquid crystal alignment film, and a liquid crystal element. and thermosetting composition to things To relate to. [Background technology]

[0002] A liquid crystal element includes a liquid crystal alignment film that has the function of aligning liquid crystal molecules in the liquid crystal layer in a specific direction. Generally, the liquid crystal alignment film is formed on the substrate by coating the substrate surface with a liquid crystal alignment agent, which is a polymer component dissolved in an organic solvent, and preferably by heating it.

[0003] In recent years, large-screen, high-definition LCD televisions have become the norm, and the proliferation of small display devices such as smartphones and tablet PCs has led to a greater demand for higher quality liquid crystal elements. Therefore, various liquid crystal alignment agents have been proposed to improve the performance of liquid crystal alignment films and enhance the various characteristics of liquid crystal elements (see, for example, Patent Document 1). Patent Document 1 discloses the inclusion of a compound having a structure in which a methylol group is bonded to an aromatic ring, together with polyimide or a polyimide precursor, in the liquid crystal alignment agent. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] International Publication No. 2010 / 074269 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] Liquid crystal elements are used not only in display terminals such as personal computers, as in the past, but also in a variety of other applications, such as LCD televisions, car navigation systems, mobile phones, smartphones, information displays, phase difference films, and dimming films. In recent years, touch panel systems have become the mainstream for liquid crystal elements in smartphones and automotive applications, making them susceptible to external forces from user keystrokes. From the perspective of improving the quality and reliability of liquid crystal elements, they are required to maintain good liquid crystal alignment, which is a fundamental characteristic, while being resistant to deterioration of display quality due to external forces, and having good mechanical properties (specifically, keystroke durability and wear resistance).

[0006] Furthermore, as the applications of liquid crystal elements expand, they are sometimes used under conditions where the backlight illuminates the liquid crystal panel for extended periods due to continuous operation for longer than before. Liquid crystal elements are required to be highly reliable and resistant to performance degradation even under such operating conditions.

[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 produce a highly reliable liquid crystal element while maintaining good liquid crystal alignment properties and good mechanical properties. [Means for solving the problem]

[0008] According to the present invention, the following means are provided.

[0009] <1> A polymer having a carboxyl group (P) and "-OX 1 The base represented by " (where X 1 It has multiple molecules (where is a hydrogen atom or a thermally leaving group), and also has "-OX 1 One or more of the bases represented by " are the X 1 A liquid crystal alignment agent containing a compound (C) which is a monovalent group having a tetrahydropyran ring structure or a tetrahydrofuran ring structure.

[0010] <2> The liquid crystal aligning agent according to <1> above, wherein the compound (C) has a partial structure represented by the following formula (1).

Chemical formula

[0011] <3> The liquid crystal aligning agent according to <1> or <2> above, wherein the compound (C) is a compound represented by the following formula (2).

Chemical formula

[0012] <4> The liquid crystal aligning agent according to any one of <1> to <3> above, wherein the compound (C) has a group represented by "-NY 1 -" (where Y 1 is a thermally detachable group). <5> The liquid crystal aligning agent according to any one of <1> to <4> above, wherein X 1 is a hydrogen atom, a substituted or unsubstituted 2-tetrahydropyranyl group, or a substituted or unsubstituted 2-tetrahydrofuranyl group. <6> The liquid crystal aligning agent according to any one of <1> to <5> above, wherein the polymer (P) is at least one selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide.

[0013] <7> The polymer (P) includes a polymer having at least one selected from the group consisting of a substructure represented by the following formula (3), a substructure represented by the following formula (4), and a substructure represented by the following formula (5). <6> The liquid crystal alignment agent described above. [ka] (In formulas (3) to (5), Z 1 Z is a tetravalent organic group. 2 Z is a divalent organic group. 3 R is a divalent organic group having a carboxyl group. 3 and R 4 These are each independently monovalent organic groups.

[0014] <8> The content ratio of compound (C) is 0.1 to 50 parts by mass with respect to 100 parts by mass of the total polymer components contained in the liquid crystal alignment agent. <1> ~ <7> A liquid crystal alignment agent as described in any of the following. <9> the above <1> ~ <8> A liquid crystal alignment film formed using any of the liquid crystal alignment agents described in one of the following. <10> the above <9> A liquid crystal element comprising the liquid crystal alignment film described above.

[0015] <11> A polymer having a carboxyl group (P) and "-OX 1 The base represented by " (where X 1 It has multiple molecules (where is a hydrogen atom or a thermally leaving group), and also has "-OX 1 One or more of the bases represented by " are the X 1 A thermosetting composition containing a compound (C) which is a monovalent group having a tetrahydropyran ring structure or a tetrahydrofuran ring structure. <12> The compound represented by the above formula (2). [Effects of the Invention]

[0016] According to the liquid crystal alignment agent of the present invention, it is possible to obtain a liquid crystal element that has good mechanical properties and is highly reliable while maintaining good liquid crystal alignment. [Brief explanation of the drawing]

[0017] [Figure 1] A figure showing the 1H-NMR spectrum of compound (AD-1). [Figure 2] A figure showing the 1H-NMR spectrum of compound (AD-2). [Figure 3] A figure showing the 1H-NMR spectrum of compound (AD-7-1). [Figure 4] A figure showing the 1H-NMR spectrum of compound (AD-8). [Modes for carrying out the invention]

[0018] Liquid crystal alignment agent The components included in the liquid crystal alignment agent of this disclosure, as well as 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.

[0019] 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 in its main chain 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 ring 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).

[0020] 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". "Tetracarboxylic acid derivatives" include tetracarboxylic dianhydrides, tetracarboxylic diesters, and tetracarboxylic diester dihalides. "(Meth)acrylic" includes acrylics and methacrylics.

[0021] The liquid crystal alignment agent of this disclosure comprises a polymer (P) having a carboxyl group and "-OX 1 The base represented by " (where X 1 The liquid crystal alignment agent contains a compound (C) having multiple hydrogen atoms or thermally desorbable groups within one molecule. The components included in the liquid crystal alignment agent of this disclosure, and optional components, will be described below.

[0022] <Polymer (P)> The polymer (P) only needs to have a carboxyl group, and its main skeleton is not particularly limited. From the viewpoint of sufficiently obtaining the effect of improving the mechanical strength of the liquid crystal alignment film and the reliability of the liquid crystal element through crosslinking reaction with compound (C), it is preferable that the polymer (P) contains structural units derived from monomers having a carboxyl group or an acid anhydride group. In particular, from the viewpoint of obtaining a liquid crystal element with excellent liquid crystal alignment and reliability, it is preferable that the polymer (P) is at least one selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, and addition polymer, and more preferably at least one selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide.

[0023] From the viewpoint of providing sufficient reactivity with compound (C), the amount of carboxyl groups in polymer (P) is preferably 0.1 mmol / g or more, more preferably 1.0 mmol / g or more, and even more preferably 2.0 mmol / g or more.

[0024] When polymer (P) is an addition polymer, examples of addition polymers include (meth)acrylic polymers, styrene polymers, maleimide polymers, and styrene-maleimide copolymers. Addition polymers having a carboxyl group can be obtained, for example, by using an unsaturated carboxylic acid such as (meth)acrylic acid, α-ethylacrylic acid, maleic acid, fumaric acid, or vinylbenzoic acid as the monomer having a carboxyl group.

[0025] When polymer (P) is at least one selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide, polymer (P) preferably has at least one selected from the group consisting of a substructure represented by the following formula (3), a substructure represented by the following formula (4), and a substructure represented by the following formula (5), and more preferably has at least the substructure represented by the following formula (3). [ka] (In formulas (3) to (5), Z 1 Z is a tetravalent organic group. 2 Z is a divalent organic group. 3 R is a divalent organic group having a carboxyl group. 3 and R 4 These are each independently monovalent organic groups.

[0026] In the above equation (3), Z 1 The tetravalent organic group represented by is a substructure derived from a tetracarboxylic dianhydride. Examples of tetracarboxylic dianhydrides include aliphatic tetracarboxylic dianhydrides and aromatic tetracarboxylic dianhydrides. Examples of aliphatic tetracarboxylic dianhydrides include linear tetracarboxylic dianhydrides and alicyclic tetracarboxylic dianhydrides. Known compounds used in the synthesis of polyamic acids, polyamic acid esters, and polyimides can be used as tetracarboxylic dianhydrides for the synthesis of polymer (P).

[0027] Specific examples of tetracarboxylic dianhydrides include, as chain-type tetracarboxylic dianhydrides, 1,2,3,4-butanetetracarboxylic dianhydride and ethylenediaminetetraacetic acid 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, 5-(2,5-dioxotetrahydrofuran-3-yl)-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, and 5-(2,5-dioxotetrahydride Examples of dianhydrides include rofuran-3-yl)-8-methyl-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride, cyclopentanetetracarboxylic acid dianhydride, cyclohexanetetracarboxylic acid dianhydride, and 3,5,6-tricarboxy-2-carboxymethylnorbornane-2:3,5:6-dianhydride. Examples of aromatic tetracarboxylic acid dianhydrides include pyromellitic acid dianhydride, 4,4'-(hexafluoroisopropylidene)diphthalic acid anhydride, ethylene glycol bisanhydrotrimate, 4,4'-carbonyl diphthalic acid anhydride, and 3,3',4,4'-biphenyltetracarboxylic acid dianhydride.

[0028] In the above equation (3), Z 2 The divalent organic group represented by is a group derived from a diamine. Also, in formulas (4) and (5) above, Z 3 The divalent organic group represented by is a group derived from a diamine containing a carboxyl group (hereinafter also referred to as "carboxyl group-containing diamine").

[0029] Z 3 The carboxyl group inside may be bonded to a chain structure or to a ring structure. 3The carboxyl group is preferably bonded directly to the aromatic ring structure or via a divalent linking group, and more preferably directly to the aromatic ring structure. When the carboxyl group is bonded to the aromatic ring structure via a divalent linking group, the divalent linking group may be, for example, any methylene group in an alkanediyl group having 1 to 3 carbon atoms or an alkanediyl group having 2 to 4 carbon atoms, which is -O-, -CO-, -COO-, -NR 6 - or -CO-NR 6 - is replaced by a divalent group (R 6 Examples include hydrogen atoms or monovalent organic groups. 3 The number of carboxyl groups present is not particularly limited, and is, for example, 1 to 4, preferably 1 or 2.

[0030] Z 3 A specific example of a divalent organic group represented by the formula shown below is the group represented by the formula shown below. [ka] (In the formula, "*" represents a combination.)

[0031] When polymer (P) contains substructures derived from carboxyl group-containing diamines, the content of these substructures is preferably 2 mol% or more, more preferably 5 mol% or more, and even more preferably 10 mol% or more, relative to the total structural units derived from the diamine in polymer (P). Furthermore, the content of substructures derived from carboxyl group-containing diamines is preferably 80 mol% or less, and more preferably 60 mol% or less, relative to the total structural units derived from the diamine in polymer (P). By setting the content of substructures derived from carboxyl group-containing diamines within the above ranges, the mechanical strength of the liquid crystal alignment film and the reliability of the liquid crystal element can be further improved through reaction with compound (C).

[0032] If polymer (P) has a substructure represented by formula (3) above, the diamine constituting polymer (P) may be a carboxyl group-containing diamine alone, a combination of a carboxyl group-containing diamine and other diamines, or a combination of other diamines alone. Furthermore, if polymer (P) has a substructure represented by formula (4) above or a substructure represented by formula (5) above, the diamine constituting polymer (P) may be a carboxyl group-containing diamine alone, or a combination of a carboxyl group-containing diamine and other diamines. Other diamines are compounds that do not have a carboxyl group. As other diamines, known compounds used in the synthesis of polyamic acids, polyamic acid esters, and polyimides can be used.

[0033] Other diamines include aliphatic diamines, aromatic diamines, and diaminoorganosiloxanes. Aliphatic diamines include linear diamines and alicyclic diamines. Specific examples of other diamines include, as linear diamines, metaxylylenediamine and hexamethylenediamine. Alicyclic diamines include 1,4-diaminocyclohexane and 4,4'-methylenebis(cyclohexylamine).

[0034] Aromatic diamines include p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylethane, 4-aminophenyl-4-aminobenzoate, 4,4'-diaminoazobenzene, 1,5-bis(4-aminophenoxy)pentane, 1,2-bis(4-aminophenoxy)ethane, 1,3-bis(4-aminophenoxy)propane, 1,6-bis(4-aminophenoxy)hexane, 6,6'-(pentamethylenedioxy)bis(3-aminopyridine), and bis[2-(4-aminophen [Nyl)ethyl]hexanediacid, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenethylurea, 4,4'-diaminodiphenethylamide, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis(4-aminophenyl)hexafluoropropane, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 4,4'-(phenylenediisopropylidene)bisaniline, the following formula [ka] [ka] [ka] (In the formula, "Boc" represents a tert-butoxycarbonyl group.) Main-chain diamines such as nitrogen-containing diamines represented by the following: Hexadecanoxy-2,4-diaminobenzene, Octadecanoxy-2,4-diaminobenzene, Octadecanoxy-2,5-diaminobenzene, Cholestanyloxy-3,5-diaminobenzene, Cholesteryloxy-3,5-diaminobenzene, Cholestanyloxy-2,4-diaminobenzene, Cholesteryloxy-2,4-diaminobenzene, Cholestanyl 3,5-diaminobenzoate, Cholesteryl 3,5-diaminobenzoate , 3,5-Lanostanyl diaminobenzoate, 3,6-Bis(4-aminobenzoyloxy)cholestane, 3,6-Bis(4-aminophenoxy)cholestane, 4-(4'-Trifluoromethoxybenzoyloxy)cyclohexyl-3,5-diaminobenzoate, 1,1-Bis(4-((aminophenyl)methyl)phenyl)-4-butylcyclohexane, 3,5-diaminobenzoate=5ξ-cholestane-3-yl, formula (E-1) [ka] (In formula (E-1), X I and X II These are, independently, a single bond, -O-, *-COO-, or *-OCO- (where "*" indicates 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.) Examples include side-chain diamines such as those represented by [formula]. Examples of diaminoorganosiloxanes include 1,3-bis(3-aminopropyl)-tetramethyldisiloxane.

[0035] Examples of compounds represented by formula (E-1) include those represented by formulas (E-1-1) to (E-1-4) below. [ka]

[0036] [Synthesis of polymers (P)] • Polyamic acid When the polymer (P) is a polyamic acid, the polyamic acid (hereinafter also referred to as "polyamic acid (P)") can be obtained by reacting a tetracarboxylic dianhydride with a diamine, along with a molecular weight modifier as needed.

[0037] In the synthesis reaction of polyamic acid (P), the ratio of tetracarboxylic dianhydride to diamine is preferably such that the acid anhydride groups of the tetracarboxylic dianhydride are 0.2 to 2 equivalents per 1 equivalent of the amino groups of the diamine. 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 ratio of molecular weight modifier used is preferably 20 parts by mass or less per 100 parts by mass of the total amount of tetracarboxylic dianhydride and diamine used.

[0038] In the synthesis reaction of polyamic acid (P), the reaction temperature is preferably -20°C to 150°C, and the reaction time is preferably 0.1 to 24 hours. Examples of organic solvents used in the reaction include aprotic polar solvents, phenolic solvents, alcoholic solvents, ketone solvents, esteric solvents, etheric solvents, halogenated hydrocarbons, and hydrocarbons. Of these, it is preferable to use 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 as the reaction solvent, or to use a mixture of one or more of these and other organic solvents (e.g., butyl cellosolve, diethylene glycol diethyl ether, etc.). The amount of organic solvent used is preferably such that the total amount of tetracarboxylic dianhydride and diamine compound is 0.1 to 50% by mass of the total amount of the reaction solution.

[0039] When a polymer solution is obtained by dissolving polyamic acid (P) through the above polymerization, this polymer solution may be used directly for the preparation of the liquid crystal alignment agent, or the polyamic acid (P) contained in the polymer solution may be isolated before being used for the preparation of the liquid crystal alignment agent.

[0040] • Polyamic acid esters When the polymer (P) is a polyamic acid ester, the polyamic acid ester may include a polymer having at least one selected from the group consisting of the substructure represented by formula (3) and the substructure represented by formula (4). Here, R in formula (4) 3 or R 4Examples of monovalent organic groups represented by include monovalent hydrocarbon groups having 1 to 10 carbon atoms, photo-aligning groups, etc. Polyamic acid esters as polymers (P) can be obtained, for example, by [I] reacting polyamic acid (P) with an esterifying agent, [II] reacting tetracarboxylic acid diester with a diamine, [III] reacting tetracarboxylic acid dihalide with a diamine, etc. Polyamic acid esters may have only an amic acid ester structure, or they may be partially esterified products 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. Alternatively, the polyamic acid ester contained in the reaction solution may be isolated, and the isolated polyamic acid ester may be used for the preparation of the liquid crystal alignment agent.

[0041] Polyimide When the polymer (P) is a polyimide, the polyimide (hereinafter also referred to as "polyimide (P)") can be obtained, for example, by dehydrating and cyclizing a polyamic acid (P) to imidize it. The imidization rate of polyimide (P) is preferably 20 to 90%, and more preferably 30 to 85%. The imidization rate is expressed as a percentage of the ratio of the number of imid ring structures to the total number of amic acid structures and imid ring structures in the polyimide.

[0042] Dehydration and ring closure of polyamic acid (P) is preferably carried out by dissolving the polyamic acid (P) in an organic solvent, adding a dehydrating agent and a dehydration and ring closure catalyst to the solution, and heating as necessary. In this method, acid anhydrides such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride can be used as the dehydrating agent. The amount of dehydrating agent used is preferably 0.01 to 20 moles per mole of the amic acid structure of polyamic acid (P). Tertiary amines such as pyridine, colidine, lutidine, and triethylamine can be used as the dehydration and ring closure catalyst. The amount of dehydration and ring closure catalyst used is preferably 0.01 to 10 moles per mole of the dehydrating agent used.

[0043] Examples of organic solvents used in the dehydration and ring-closing reaction include those exemplified for use in the synthesis of polyamic acid (P). The reaction temperature for the dehydration and ring-closing reaction is preferably 0 to 180°C. The reaction time is preferably 1.0 to 120 hours. The reaction solution containing polyimide (P) may be used directly for the preparation of the liquid crystal alignment agent. Alternatively, polyimide (P) may be isolated from the reaction solution and the isolated polyimide (P) may be used for the preparation of the liquid crystal alignment agent. Polyimide (P) can also be obtained by dehydration and ring-closing of polyamic acid esters.

[0044] The solution viscosity of the polymer (P) is preferably 10 to 800 mPa·s when it is a 10% by mass solution, and more preferably 15 to 500 mPa·s. The solution viscosity (mPa·s) is the value measured at 25°C using an E-type rotational viscometer for a 10% by mass polymer solution prepared using a good solvent for the polymer (P) (e.g., γ-butyrolactone, N-methyl-2-pyrrolidone, etc.).

[0045] The weight-average molecular weight (Mw) of the polymer (P), measured by gel permeation chromatography (GPC) in terms of polystyrene, is preferably 1,000 to 500,000, and more preferably 2,000 to 300,000. The molecular weight distribution (Mw / Mn), expressed as the ratio of Mw to the number-average molecular weight (Mn) measured by GPC in terms of polystyrene, is preferably 7 or less, and more preferably 5 or less.

[0046] The content of polymer (P) 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 amount of solids contained in the liquid crystal alignment agent (i.e., the total mass of components other than the solvent in the liquid crystal alignment agent).

[0047] <Compound (C)> Compound (C) is "-OX 1 The base represented by " (where X1 Compound (C) has multiple hydrogen atoms or thermally leaving groups within a single molecule. 1 One or more of the bases represented by " are X 1 It is a monovalent group having a tetrahydropyran ring structure or a tetrahydrofuran ring structure.

[0048] ["-OX" 1 [Regarding the base represented by "] X 1 The thermally desorbable group represented by X is a substituent that is removed by the heat generated during the fabrication of the liquid crystal alignment film and replaced by a hydrogen atom. 1 Examples of thermally detachable groups represented by include ether-based thermally detachable groups such as C1-C7 alkyl groups, C3-C12 monovalent alicyclic saturated hydrocarbon groups, benzyl groups, and p-methoxybenzyl groups; acetal-based thermally detachable groups such as C2-C6 alkoxyalkyl groups, substituted or unsubstituted 2-tetrahydrofuranyl groups, and substituted or unsubstituted 2-tetrahydropyranyl groups; acyl-based thermally detachable groups such as acetyl groups and benzoyl groups; allyl-based thermally detachable groups such as allyl groups and methallyl groups; and silyl ether-based thermally detachable groups such as trimethylsilyl groups, triethylsilyl groups, and tert-butyldimethylsilyl groups.

[0049] Of the above, the alkyl group having 1 to 7 carbon atoms may be linear or branched, and examples include methyl group, ethyl group, n-propyl group, sec-butyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, etc. The monovalent alicyclic saturated hydrocarbon group having 3 to 12 carbon atoms may be monocyclic or polycyclic. Examples of monovalent alicyclic saturated hydrocarbon groups having 3 to 12 carbon atoms include monocyclic alicyclic saturated hydrocarbon groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, and cyclohexyl group; and polycyclic alicyclic saturated hydrocarbon groups such as norbornyl group and adamantyl group. The alicyclic saturated hydrocarbon group may have substituents on the ring portion. Examples of substituents include methyl group and ethyl group.

[0050] Examples of alkoxyalkyl groups having 2 to 6 carbon atoms include methoxymethyl group and ethoxyethyl group. In substituted 2-tetrahydrofuranyl groups and substituted 2-tetrahydropyranyl groups, examples of substituents include C1-C3 alkyl groups, C1-C3 alkoxy groups, acetoxy groups, benzyloxy groups, and the like. Specific examples of substituted or unsubstituted 2-tetrahydropyranyl groups and substituted or unsubstituted 2-tetrahydrofuranyl groups include the groups represented by the following formulas. [ka]

[0051] X 1 The thermally detachable group represented by is preferably a substituted or unsubstituted 2-tetrahydropyranyl group, more preferably a substituted or unsubstituted 2-tetrahydrofuranyl group, and even more preferably an unsubstituted 2-tetrahydropyranyl group, in that it can increase the hydrophobicity of compound (C) and the reaction rate in the thermal detachment reaction is relatively low.

[0052] "-OX" 1 The group represented by " is preferably bonded to an aliphatic hydrocarbon structure, and more preferably bonded to a saturated chain hydrocarbon structure, from the viewpoint of reactivity. Specifically, compound (C) preferably has multiple substructures represented by the following formula (x-1) within one molecule. [ka] (In formula (x-1), X 1 R is a hydrogen atom or a thermally leaving group. 5 This refers to a chain-like or branched alkanediyl group having 1 to 5 carbon atoms. (* indicates a bond.)

[0053] In formula (x-1), R 5 From the viewpoint of reactivity, it is preferably an alkanediyl group having 1 to 3 carbon atoms, and particularly preferably an ethylene group. 1Specific and preferred examples include groups similar to those exemplified in the above description. "*" is preferably a bond that connects to a nitrogen atom.

[0054] Compound (C) possesses "-OX 1 The group represented by " is a part of the X in compound (C). 1 The group may be a monovalent group having a tetrahydropyran ring structure or a tetrahydrofuran ring structure, and all X 1 The group may be a monovalent group having a tetrahydropyran ring structure or a tetrahydrofuran ring structure. The storage stability and thermal stability of compound (C) can be increased, and a liquid crystal alignment film can be obtained that achieves both liquid crystal alignment and mechanical strength, which is due to the presence of "-OX" in compound (C). 1 All X of the base represented by " 1 However, it is preferable that the group is a monovalent group having a tetrahydropyran ring structure or a tetrahydrofuran ring structure, and more preferably a monovalent group having a tetrahydropyran ring structure.

[0055] Compound (C) possesses "-OX 1 The number of groups represented by " is preferably 2 to 10, more preferably 3 to 8, and even more preferably 3 to 6, from the viewpoint of achieving a good balance between the mechanical strength and liquid crystal alignment properties of the liquid crystal alignment film.

[0056] Compound (C) is preferably a β-hydroxyalkylamide structure in that it can react with the carboxyl groups of polymer (P) at relatively low temperatures to form a crosslinked structure. Specifically, compound (C) is preferably a substructure represented by the following formula (1). [ka] (In formula (1), X 1 R is a hydrogen atom or a thermally leaving group. 1a R is a hydrogen atom or a monovalent organic group having 1 to 4 carbon atoms. 1b and R 1c Each of these is independently a hydrogen atom or a monovalent organic group having 1 to 8 carbon atoms. (* represents a bond.)

[0057] In the above equation (1), R 1a The monovalent organic group having 1 to 4 carbon atoms represented by is preferably a linear or branched alkyl group having 1 to 4 carbon atoms, and more preferably a methyl group or an ethyl group. From the viewpoint of increasing the reactivity of compound (C), R 1a Among these, a hydrogen atom or a methyl group is preferred, and a hydrogen atom is more preferred. 1b and R 1c A monovalent organic group with 1 to 8 carbon atoms, represented as "-OX", is a monovalent organic group with 1 to 8 carbon atoms. 1 It is preferable to have a group represented by ". From the viewpoint of increasing the reactivity of compound (C), R 1b and R 1c A hydrogen atom is preferred. 1 Specific and preferred examples include groups similar to those exemplified in the above description.

[0058] A monovalent group may be bonded to the nitrogen atom in formula (1) above. Furthermore, the nitrogen atom in formula (1) may, together with an adjacent carbonyl group, form part of a ring. When a monovalent group is bonded to the nitrogen atom in formula (1), examples of such monovalent groups include thermally leavenable groups, hydroxyalkyl groups, and protected hydroxyalkyl groups. When the nitrogen atom in formula (1) forms part of a ring together with a carbonyl group, examples of such rings include isocyanurate rings and imidazolidinone rings.

[0059] Specifically, compound (C) is preferably a compound represented by the following formula (2). [ka] (In formula (2), X 1 X is a hydrogen atom or a thermally desorbable group. However, the four X in the formula 1 They are identical or different, 4 X 1 One or more of these are monovalent groups having a tetrahydropyran ring structure or a tetrahydrofuran ring structure. 2 (This is a divalent organic group.)

[0060] In the above formula (2), R 2 The divalent organic group represented by is a substituted or unsubstituted divalent hydrocarbon group, and any methylene group in the hydrocarbon group is -O-, -S-, -NR 7 -, -CONR 7 -, -CO-, -COO-, -NR 7 -CO-NR 8 -, -NR 7 -CO-O-, -CONR 7 -NR 8 CO-, etc. (where R 7 And R 8 Are each independently a hydrogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms, or a thermally desorbable group).) And the like.

[0061] When R 2 Is a divalent hydrocarbon group, examples of the hydrocarbon group include an alkanediyl group having 1 to 12 carbon atoms, an alkenediyl group having 2 to 12 carbon atoms, a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and a divalent aromatic hydrocarbon group having 6 to 20 carbon atoms. Among these, the divalent hydrocarbon group represented by R 2 Is preferably a chain hydrocarbon group or an alicyclic hydrocarbon group, more preferably an alkanediyl group having 1 to 12 carbon atoms, an alkenediyl group having 2 to 12 carbon atoms, or a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms. Among these, particularly preferably, an alkanediyl group having 1 to 12 carbon atoms or an alkenediyl group having 2 to 12 carbon atoms, more preferably an alkanediyl group having 1 to 6 carbon atoms or an alkenediyl group having 2 to 6 carbon atoms, and further preferably an alkanediyl group having 1 to 4 carbon atoms or an alkenediyl group having 2 to 4 carbon atoms. When R 2 Is a chain group (such as an alkanediyl group or an alkenediyl group), it may be linear or branched. From the viewpoint of enhancing the liquid crystal alignment property and mechanical strength, R 2 Is preferably linear. When R 2 Is a substituted divalent hydrocarbon group, examples of the substituent include a hydroxyl group, a carboxyl group, a halogen atom, etc.

[0062] When R 2However, a divalent group (hereinafter referred to as "divalent group R") is formed when any methylene group in a substituted or unsubstituted hydrocarbon group is replaced by a heteroatom-containing group. 8 In the case of a substituted or unsubstituted hydrocarbon group, a specific example is a group in which one or more methylene groups in the substituted or unsubstituted hydrocarbon group as exemplified above are replaced by a heteroatom-containing group. Divalent group R 8 The group may be a chain-like structure, or it may have a cyclic structure (aliphatic hydrocarbon ring, aromatic hydrocarbon ring, aliphatic heterocycle, aromatic heterocycle, etc.). Examples of aliphatic heterocycles include piperidine rings and piperazine rings as nitrogen-containing aliphatic heterocycles; oxetane rings, tetrahydrofuran rings, dioxolane rings, etc. as oxygen-containing aliphatic heterocycles; and tetrahydrothiophene rings, etc. as sulfur-containing aliphatic heterocycles. Examples of aromatic heterocycles include pyridine rings, pyrimidine rings, pyridazine rings, and pyrazine rings as nitrogen-containing aromatic heterocycles; furan rings, etc. as oxygen-containing aromatic heterocycles; and thiophene rings, etc. as sulfur-containing aromatic heterocycles.

[0063] In terms of being able to obtain a liquid crystal element with high mechanical strength and reliability while maintaining good liquid crystal alignment, R 2 Among the above, this refers to a divalent chain hydrocarbon group, a divalent alicyclic hydrocarbon group, or any methylene group in the hydrocarbon group that contains a heteroatom (preferably -O-, -S-, -NR). 7 -, -CONR 7 -, -CO-, -COE-, -NR 7 -CO-NR 8 -, -NR 7 -CO-O- or -CONR 7 -NR 8 It is preferable that the group is a divalent group that is replaced by CO-, and more preferably that the group is a divalent linear hydrocarbon group or a divalent group in which any methylene group in a linear hydrocarbon group is replaced by a heteroatom-containing group. In this case, R 2 The number of carbon atoms is preferably 1 to 20, more preferably 1 to 12, and even more preferably 1 to 6.

[0064] Compound (C) contains "-NY" in its molecule. 1 - represents the base (where Y 1 It is preferable that the compound (C) has a thermally leaving group. 1 When compound (C) has a group represented by "-", it is preferable in that the reliability of the liquid crystal element can be made better. When compound (C) is a compound represented by the above formula (2), the compound is R in the above formula (2). 2 -NY 1 It is preferable to have a group represented by "-".

[0065] Y 1 Examples of thermally detachable groups represented by include carbamate-based thermally detachable groups, amide-based thermally detachable groups, imide-based thermally detachable groups, and sulfonamide-based thermally detachable groups. Of these, carbamate-based thermally detachable groups are preferred due to their high thermal detachability. Specific examples include tert-butoxycarbonyl group, benzyloxycarbonyl group, 1,1-dimethyl-2-haloethyloxycarbonyl group, allyloxycarbonyl group, 2-(trimethylsilyl)ethoxycarbonyl group, 9-fluorenylmethyloxycarbonyl group, and allyloxycarbonyl group. Among these, tert-butoxycarbonyl group (Boc group) is particularly preferred due to its excellent thermal detachability and the ability to reduce the amount of residue remaining in the film after deprotection.

[0066] Compound (C) is "-NY 1 If a compound (C) has a group represented by "-", then within one molecule of compound (C), "-NY 1 The number of groups represented by "-" is not particularly limited; there must be one or more. 1 The number of elements represented by "-" is, for example, 1 to 4.

[0067] "-NY 1The group represented by "-" preferably has one or both bonds bonded to an aliphatic hydrocarbon structure, and more preferably both bonds bonded to an aliphatic hydrocarbon structure, from the viewpoint of the crosslinkability of compound (C) and the reliability of the resulting liquid crystal alignment film. The aliphatic hydrocarbon structure may be saturated or unsaturated, and may be linear or cyclic. 1 The aliphatic hydrocarbon structure adjacent to the group represented by "-" is preferably a chain structure, and more preferably a saturated chain structure (i.e., an alkanediyl group).

[0068] R in equation (2) above 2 -NY 1 If it has a group represented by -, heating during film formation results in Y 1 By detaching, -NH- (a basic functional group) is generated, and the resulting -NH- captures acidic impurities in the liquid crystal cell, thereby improving the reliability of the liquid crystal element. 2 Inside "-NY 1 The number of units represented by "-" is preferably 1 or 2.

[0069] X 1 Specific and preferred examples include groups similar to those exemplified in the above description. 1 A preferred specific example of a monovalent group having a tetrahydropyran ring structure or a tetrahydrofuran ring structure is a group represented by any of the following formulas (x2-1) to (x2-5). Of these, X 1 It is preferable that the group is represented by either formula (x2-1) or formula (x2-2) below. [ka] (In equations (x2-1) to (x2-5), "*" represents a combination.)

[0070] Specific examples of compound (C) include compounds represented by formulas (c-1) to (c-31) below. [ka] [ka] [ka] [ka] (In formulas (c-1) to (c-31), X 2 x is a hydrogen atom or a group represented by any of the above formulas (x2-1) to (x2-5). However, multiple X in the formula 2 They are the same or different, multiple X 2 One or more of these elements are bases represented by any of the above equations (x²-1) to (x²-5). In equation (c-23), n is an integer between 1 and 5.

[0071] Compound (C) is preferably one of the compounds represented by formulas (c-1) to (c-4), (c-13) to (c-15), (c-18) to (c-21), (c-24), (c-28), and (c-29), more preferably one of the compounds represented by formulas (c-1) to (c-4), (c-13) to (c-15), and (c-18) to (c-21), and even more preferably one of the compounds represented by formulas (c-1), (c-2), (c-13), (c-14), (c-18), and (c-20).

[0072] In the liquid crystal alignment agent of this disclosure, the content of compound (C) is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and even more preferably 3 parts by mass or more, per 100 parts by mass of the total amount of polymer components contained in the liquid crystal alignment agent, from the viewpoint of obtaining a liquid crystal alignment film with high mechanical strength and a highly reliable liquid crystal element. Furthermore, from the viewpoint of suppressing a decrease in the toughness of the liquid crystal alignment film, the content of compound (C) is preferably 50 parts by mass or less, more preferably 40 parts by mass or less, and even more preferably 30 parts by mass or less, per 100 parts by mass of the total amount of polymer components contained in the liquid crystal alignment agent.

[0073] [Synthesis of compound (C)] Compound (C) can be synthesized by appropriately combining standard organic chemistry methods. One example of a method for synthesizing compound (C) is to react a carboxylic acid or its derivative with a hydroxyalkylamine to produce compound (C) with X 1 One method involves synthesizing an intermediate in which all atoms are hydrogen atoms and protecting the hydroxyl groups of the intermediate with a thermally leaving group, or synthesizing an intermediate by protecting the hydroxyl groups of a hydroxyalkylamine with a thermally leaving group and then reacting the intermediate with a carboxylic acid or its derivative. These methods are simple and can yield compound (C) in high yield.

[0074] Examples of carboxylic acids include succinic acid, adipic acid, and glutaric acid. Examples of carboxylic acid derivatives include lower alkyl esters of carboxylic acids, anhydrides of carboxylic acids, chlorides of carboxylic acids, and isocyanates. Examples of hydroxyalkylamines include N-methylethanolamine, diethanolamine, and N-methylpropanolamine. The method for obtaining compound (C) is not limited to the method described above.

[0075] <Other ingredients> The liquid crystal alignment agent may contain, in addition to the polymer (P) and compound (C), components other than the polymer (P) and compound (C) (hereinafter also referred to as "other components") as needed.

[0076] • Other polymers The liquid crystal alignment agent of this disclosure may further contain polymers that do not have carboxyl groups (hereinafter also referred to as "other polymers"). The main skeleton of the other polymers is not particularly limited. Examples of other polymers include polyorganosiloxanes, polyesters, polyenamines, polyureas, polyamides, and addition polymers (e.g., (meth)acrylic polymers, styrene polymers, maleimide polymers, styrene-maleimide copolymers). Of these, it is preferable that the other polymers are at least one selected from the group consisting of polyorganosiloxanes and addition polymers.

[0077] When other polymers are included in the liquid crystal alignment agent, the content ratio of the other polymers is preferably 40 parts by mass or less, and more preferably 30 parts by mass or less, per 100 parts by mass of the polymer components contained in the liquid crystal alignment agent (i.e., the total amount of polymer (P) and other polymers).

[0078] ·solvent The liquid crystal alignment agent of this disclosure is prepared as a liquid composition comprising a polymer (P), a compound (C), and other components used as needed, preferably dispersed or dissolved in a suitable solvent.

[0079] Organic solvents are preferred as solvents. Specific examples include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 1,2-dimethyl-2-imidazolidinone, 1,3-dimethyl-2-imidazolidinone, phenol, γ-butyrolactone, γ-butyrolactam, N,N-dimethylformamide, N,N-dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone, diacetone alcohol, 1-hexanol, 2-hexanol, propane-1,2-diol, 3-methoxy-1-butanol, ethylene glycol monomethyl ether, methyl lactate, ethyl lactate, butyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl acetoacetate, ethyl acetoethyl acetate, ethyl propionate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, and ethylene glycol-i-propyl ether. Examples of solvents 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, propylene glycol monomethyl ether (PGME), diethylene glycol diethyl ether acetate, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol diacetate, cyclopentanone, and cyclohexanone. As solvents, one type can be used alone or two or more types can be used in combination.

[0080] Other components that can be incorporated into the liquid crystal alignment agent include, in addition to those mentioned above, adhesion aids, antioxidants, metal chelating compounds, curing accelerators, surfactants, fillers, dispersants, photosensitizers, and the like. The proportion of these other components can be appropriately selected depending on the compound, as long as it does not impair the effects of the present disclosure.

[0081] 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. The solid content concentration of the liquid crystal alignment agent is preferably in the range of 1 to 10% by mass. A solid content concentration of 1% by mass or more is preferable because it allows for sufficient film thickness of the coating and enables the production of a liquid crystal alignment film exhibiting better liquid crystal alignment properties. On the other hand, a solid content concentration of 10% by mass or less allows for a coating film of appropriate thickness, making it easier to obtain a liquid crystal alignment film exhibiting good liquid crystal alignment properties, and the viscosity of the liquid crystal alignment agent tends to be appropriate, resulting in good coatability.

[0082] <Liquid crystal alignment films and liquid crystal elements> The liquid crystal alignment film of this disclosure is manufactured using 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 liquid crystal driving method 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 type, FFS type, OCB (Optically Compensated Bend) type, PSA (Polymer Sustained Alignment) type, and ECB (Electrically Controlled Birefringence) 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.

[0083] <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. As the substrate, for example, glass such as float glass or soda glass; or transparent substrates made of plastics such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, or poly(alicyclic olefin) can be used. As the transparent conductive film provided on one side of the substrate, a NESA film (registered trademark of PPG, Inc., USA) made of tin oxide (SnO2), or an ITO film made of indium oxide-tin oxide (In2O3-SnO2) 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.

[0084] The method for applying the liquid crystal alignment agent to the substrate is not particularly limited. The liquid crystal alignment agent can be applied to the substrate by, for example, a spin coating method, a printing method (e.g., offset printing method, flexographic printing method, etc.), an inkjet method, a slit coating method, a bar coater method, an extrusion die method, a direct gravure coater method, a chamber doctor coater method, an offset gravure coater method, an impregnation coater method, an MB coater method, etc.

[0085] 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. After that, a firing (post-bake) step is performed to completely remove the solvent and, if necessary, to thermally imide the amic acid structure present in the polymer. The firing temperature (post-bake temperature) at this time is preferably 80 to 280°C, more preferably 80 to 250°C. The post-bake time is preferably 5 to 200 minutes. The film thickness of the formed film is preferably 0.001 to 1 μm.

[0086] <Step 2: Orientation Treatment> When manufacturing TN, STN, IPS, or FFS type liquid crystal elements, the coating film formed in step 1 is subjected to a process (alignment treatment) to impart liquid crystal alignment ability. This imparts the liquid crystal molecule alignment ability to the coating film, making it a liquid crystal alignment film. As the alignment treatment, it is preferable to use a rubbing treatment in which the surface of the coating film formed on the substrate is rubbed with cotton or nylon, or a photo-alignment treatment in which the coating film is irradiated with light to impart liquid crystal alignment ability. When manufacturing vertically aligned liquid crystal elements, the coating film formed in step 1 may be used as is as a liquid crystal alignment film, or 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 vertically aligned liquid crystal elements can also be preferably used for PSA type liquid crystal elements.

[0087] Light irradiation for photo-alignment can be carried out 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 carried out 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.

[0088] 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 is preferably 200 to 30,000 J / m². 2 And more preferably, 500~10,000 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.

[0089] <Step 3: Liquid Crystal Cell Construction> A liquid crystal cell is manufactured by preparing two substrates on which a liquid crystal alignment film is formed as described above, and placing liquid crystal between the two substrates which are placed opposite each other. Methods for manufacturing a liquid crystal cell include, for example, placing two substrates opposite each other with a gap in between so that the liquid crystal alignment films face each other, bonding the periphery of the two substrates with a sealant, injecting and filling the cell gap surrounded by the substrate surface and the sealant, and sealing the injection hole, or the ODF method. As the sealant, for example, an epoxy resin containing a curing agent and aluminum oxide spheres as spacers can be used. Examples of liquid crystals include nematic liquid crystals and smectic liquid crystals, with nematic liquid crystals being preferred.

[0090] In PSA mode, a polymerizable compound (e.g., a polyfunctional (meth)acrylate compound) is packed into the cell gap along with the liquid crystal, and after the liquid crystal cell is constructed, a voltage is applied between the conductive films of a pair of substrates, and the liquid crystal cell is irradiated with light. When manufacturing a PSA type liquid crystal element, the proportion of polymerizable compound used is, for example, 0.01 to 3 parts by mass, preferably 0.05 to 1 part by mass, per 100 parts by mass of the total liquid crystal.

[0091] When manufacturing liquid crystal display devices, a polarizing plate is then bonded to the outer surface of the liquid crystal cell. Examples of polarizing plates include a polarizing film called an "H film," which is made by stretching and oriented polyvinyl alcohol while absorbing iodine, sandwiched between cellulose acetate protective films, or a polarizing plate made of the H film itself.

[0092] 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.

[0093] ≪Thermosetting composition≫ The thermosetting composition of this disclosure comprises a polymer (P) having a carboxyl group and "-OX 1 The base represented by " (where X 1 It has multiple molecules (where is a hydrogen atom or a thermally leaving group), and also has "-OX 1 One or more of the bases represented by " are the above X 1 It contains a compound (C) which is a monovalent group having a tetrahydropyran ring structure or a tetrahydrofuran ring structure.

[0094] The polymer (P) and compound (C) contained in the thermosetting composition of this disclosure, as well as other optionally added components, are as described above.

[0095] A polymer composition containing polymer (P) and compound (C) forms a crosslinked structure upon heat and exhibits thermosetting properties. Therefore, according to the thermosetting composition of this disclosure, when used, for example, as an adhesive, dispersant, or coating agent, a cured product with excellent thermosetting properties can be obtained. Furthermore, according to the thermosetting composition of this disclosure, it is also possible to obtain a cured product with excellent heat resistance, adhesion, and flexibility. [Examples]

[0096] The present invention will be described in more detail below with reference to examples, but it is not limited to these examples.

[0097] <Structure and abbreviation of the compound> The main compounds used in the following examples have structures and abbreviations as follows: [Tetracarboxylic acid dianhydride] Compounds (TA-1) to (TA-5); compounds represented by the following formulas (TA-1) to (TA-5). [ka]

[0098] [Diamine] Compounds (DA-1) to (DA-14); compounds represented by the following formulas (DA-1) to (DA-14). [ka]

[0099] [Crosslinking agent] Compounds (AD-1) to Compounds (AD-12); compounds represented by the following formulas (AD-1) to (AD-12). [ka]

[0100] [solvent] NMP; N-methyl-2-pyrrolidone BC; Butyl cellosolve

[0101] <Synthesis of Compounds> [Synthesis Example 1] In a three-necked flask equipped with a nitrogen inlet tube, N,N,N',N'-tetrakis(2-hydroxyethyl)adipamide (10 mmol), 3,4-dihydropyran (60 mmol), pyridinium p-toluenesulfonate (2 mmol), and methylene chloride (50 mL) were added and heated and stirred under nitrogen at 30°C for 12 hours. After the reaction was complete, water was added and the mixture was separated and washed, and the organic phase was vacuum dried to obtain a colorless, viscous liquid compound represented by the following formula (AD-1) in 99% yield. Figure 1 shows the compound (AD-1). 1 The measurement results of the H-NMR spectrum (DMSO-d6, 400MHz) are shown. [ka]

[0102] [Synthesis Example 2] Compound (AD-2) was synthesized in the same manner as in Synthesis Example 1, according to the reaction scheme below. Figure 2 shows the reaction of compound (AD-2). 1 The measurement results of the H-NMR spectrum (DMSO-d6, 400MHz) are shown. [ka]

[0103] [Synthesis Example 3] In a three-necked flask equipped with a nitrogen inlet tube, diethanolamine (50 mmol) and acetonitrile (50 mL) were added and cooled to 0°C. Then methanesulfonic acid (55 mmol) was added, and 3,4-dihydropyran (125 mmol) was added dropwise, and the mixture was stirred at room temperature under nitrogen for 12 hours. After the reaction was complete, the mixture was cooled to 0°C, potassium hydroxide aqueous solution was added little by little to quench the reaction, ethyl acetate (50 mL) was added, water was added for liquid-liquid washing, and the organic phase was vacuum-dried to obtain the compound O,O'-bis(2-tetrahydropyranyl)-diethanolamine, represented by the following formula (AD-7-1), in 46% yield as a brown liquid. Figure 3 shows the compound (AD-7-1). 1 The measurement results of the H-NMR spectrum (CDCl3, 400MHz) are shown. [ka]

[0104] [Synthesis Example 4] Compound (AD-7) was synthesized according to the reaction scheme shown below. [ka]

[0105] [Synthesis Example 5] Compound (AD-8) was synthesized according to the reaction scheme below. N,N'-di(tert-butoxycarbonyl)-ethane-1,2-diamine-N,N'-diacetic acid was synthesized according to the description in Patent Document: International Publication No. 2005 / 061005. Figure 4 shows the reaction of compound (AD-8). 1 The measurement results of the H-NMR spectrum (CDCl3, 400MHz) are shown. [ka]

[0106] [Synthesis Example 6] Compound (AD-11) was synthesized according to the reaction scheme shown below. [ka]

[0107] [Synthesis Example 7] Compound (AD-12) was synthesized according to the reaction scheme shown below. [ka]

[0108] [Reference synthesis example 1] Compound (AD-3) was synthesized according to the description in Korean Published Patent No. 2019-125717. [Reference synthesis example 2] Compound (AD-4) was synthesized in accordance with the description in Korean Published Patent No. 2019-087819. [Reference synthesis example 3] Compound (AD-9) was synthesized according to the description in International Publication No. 2021 / 006182. [Reference synthesis example 4] Compound (AD-10) was synthesized according to the reaction scheme shown below. [ka]

[0109] <Evaluation of Compounds> The following evaluations were performed for each crosslinking agent (compounds (AD-1) to (AD-12)). The evaluation results are shown in Table 1 below.

[0110] [Evaluation of storage stability] Dissolve the crosslinking agent and p-nitrobenzoic acid in water to a total of 1% by mass each in deuterated dimethyl sulfoxide, at room temperature. 1 1H-NMR was measured. Subsequently, the solution was stored at room temperature for two weeks and then measured again. 1 1H NMR was measured before and after storage at room temperature. 1 Changes in the H-NMR spectrum (400 MHz) were observed. The evaluation was "good" if there was no change and "poor" if there was a change.

[0111] [Evaluation of thermal stability] Thermogravimetric analysis was performed on each crosslinking agent under nitrogen conditions, at a heating rate of 10°C per minute, from 30°C to 500°C. For evaluation, the 5% weight loss temperature Td5 was calculated (however, if the crosslinking agent had a protecting group, the temperature at which the weight decreased by 5% relative to the weight excluding the protecting group was calculated). A Td5 of 230°C or higher was considered "good," and a Td5 below 230°C was considered "poor."

[0112] [Evaluation of hydrophobicity] For each crosslinking agent, the solubility parameter δ(cal) was determined using the computer software HSPiP (version 5.2.07). 0.5 cm -1.5 The following criteria were used for evaluation: δ less than 10 was rated "Excellent," δ between 10 and 12 was rated "Good," and δ 12 or higher was rated "Poor."

[0113] [Table 1]

[0114] As shown in Table 1, "-OX 1 It has multiple groups represented by " in one molecule, and one or more X 1Compounds (AD-1), (AD-2), (AD-7), (AD-8), (AD-11), and (AD-12) having a tetrahydropyran or tetrahydrofuran structure were evaluated as having good storage stability, thermal stability, and hydrophobicity.

[0115] <Synthesis and Evaluation of Polymers> The polymers were synthesized according to the following synthesis examples 8-17. In the following examples, the weight-average molecular weight (M) of the polymer is calculated. w ) and number-average molecular weight (M n The imidization rate of polyimide in the polymer solution, the viscosity of the polymer solution, and the epoxy equivalent of the polymer were measured by the following methods.

[0116] [Weight average molecular weight M w and number average molecular weight M n ] M w and M n This is the polystyrene equivalent value measured by GPC under the following conditions. Column: TSKgelGRCXLII, manufactured by Tosoh Corporation. Solvent: Tetrahydrofuran Temperature: 40℃ Pressure: 68 kgf / cm² 2

[0117] [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 material, at room temperature. 1 The 1H-NMR spectrum was measured. 1 The imidization rate [%] was determined from the 1H-NMR spectrum (400 MHz) using the following formula (1). Imidization rate [%] = (1 - (A1 / (A2 × α))) × 100 …(1) (In formula (1), A1 is the peak area derived from the proton of the amide group appearing around a chemical shift of 10 ppm, A2 is the peak area derived from the proton of the aromatic group appearing around a chemical shift of 6-9 ppm, and α is the ratio of the number of protons of the aromatic group to one proton of the amide group in the polymer precursor (polyamic acid).)

[0118] [Solution viscosity of polymer solutions] The solution viscosity (mPa·s) of the polymer solution was measured at 25°C using an E-type rotational viscometer. [Epoxy equivalent] The epoxy equivalent was measured by the hydrochloride-methyl ethyl ketone method described in JIS C 2105.

[0119] [Synthesis Example 8] Diamines (50 moles of diamine (DA-1), 30 moles of diamine (DA-2), and 20 moles of diamine (DA-3) per 100 moles of total diamine used) were dissolved in NMP, and 0.95 mole equivalents of tetracarboxylic dianhydride (TA-2) relative to the total amount of diamine were added. The reaction was carried out at room temperature for 6 hours to obtain a polyamic acid solution. To the obtained solution, 0.40 mole equivalents of 1-methylpiperidine and acetic anhydride relative to the carboxyl groups of the polyamic acid were added as dehydrating agents, and the mixture was heated and stirred at 60°C for 3 hours. The obtained solution was repeatedly concentrated under reduced pressure and diluted with NMP to obtain a 10% by mass solution of polyimide (PI-1). The imidization rate of polyimide (PI-1) was 50%.

[0120] [Synthesis Example 9] A 10% by mass solution of polyimide (PI-2) was obtained in the same manner as in Synthesis Example 8, except that the types and molar ratios of the tetracarboxylic dianhydride and diamine were changed as shown in Table 2 below. The imidization rate of polyimide (PI-2) was 50%. [Synthesis Example 10] A 10% by mass solution of polyimide (PI-3) was obtained in the same manner as in Synthesis Example 8, except that the molar ratio of the dehydrating agent was changed to 1.20 molar equivalents. The imidization rate of polyimide (PI-3) was 100%.

[0121] [Synthesis Example 11] Diamines (30 moles of diamine (DA-3), 40 moles of diamine (DA-5), 20 moles of diamine (DA-6), and 10 moles of diamine (DA-7) per 100 moles of total diamines used) were dissolved in NMP, and 0.95 mole equivalents of tetracarboxylic dianhydride (70 moles of acidic dianhydride (TA-1) and 30 moles of acidic dianhydride (TA-4) per 100 moles of total tetracarboxylic dianhydride used) were added relative to the total amount of diamines. The reaction was carried out at room temperature for 6 hours to obtain a 15% by mass solution of polyamic acid (PA-1).

[0122] [Synthesis Examples 12-15] Solutions containing 15% by mass each of polyamic acids (PA-2) to (PA-5) were obtained in the same manner as in Synthesis Example 11, except that the types and molar ratios of tetracarboxylic dianhydrides and diamines were changed as shown in Table 2 below.

[0123] [Table 2]

[0124] The values ​​in Table 2 indicate the percentage (mol%) of each compound used relative to the total amount (100 mol%) of tetracarboxylic dianhydrides used in the synthesis for acid dianhydrides, and the percentage (mol%) of each compound used relative to the total amount (100 mol%) of diamines used in the synthesis for diamines.

[0125] [Synthesis Example 16] In a reaction vessel equipped with a stirrer, thermometer, dropping funnel, and reflux condenser, 100.0 g of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane (a compound represented by formula (S-1) below), 500 g of methyl isobutyl ketone, and 10.0 g of triethylamine were charged and mixed at room temperature. Next, 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. Then, the solvent and water were removed under reduced pressure to obtain a polyorganosiloxane (ESSQ-1) containing epoxy groups as a viscous transparent liquid. Regarding polyorganosiloxane (ESSQ-1), 1 ¹H-NMR analysis revealed a peak based on epoxy groups at a chemical shift (δ) of approximately 3.2 ppm, confirming that no side reactions of epoxy groups occurred during the reaction. The weight-average molecular weight of the obtained polyorganosiloxane (ESSQ-1) was M w The coefficient was 3,500, and the epoxy equivalent was 180 g / mol. In a 200 mL three-necked flask, 10.0 g of polyorganosiloxane (ESSQ-1), 30.28 g of methyl isobutyl ketone as a solvent, and compounds represented by the following formulas (S-2 and S-3) as modifying components (carboxylic acids) in amounts corresponding to 20 mol% and 10 mol%, respectively, relative to the total amount of epoxy groups in the polyorganosiloxane (ESSQ-1), and 0.10 g of UCAT 18X ​​(trade name, manufactured by Sunapro Co., Ltd.) as a 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 polyorganosiloxane (PSQ-1) containing directing groups. The weight-average molecular weight of the obtained polymer was M w It was 8000. [ka]

[0126] [Synthesis Example 17] Under nitrogen, 6.38 g of the compound represented by formula (M-1) below, 1.90 g of 4-(glycidyloxymethyl)styrene (the compound represented by formula (M-2) below), and 0.86 g of methacrylic acid were added to a 100 mL two-necked flask as polymerization monomers, 0.46 g of 2,2'-azobis(2,4-dimethylvaleronitrile) as a radical polymerization initiator, and 40 ml of N-methyl-2-pyrrolidone (NMP) as a solvent. 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 the target polymer (PMI-1). The weight-average molecular weight M of the obtained polymer was... w is 30000, molecular weight distribution M w / M n The answer was 2. [ka]

[0127] <Preparation and evaluation of liquid crystal alignment agents> [Example 1: Photo-aligned FFS type liquid crystal display element] (1) Preparation of liquid crystal alignment agent A solution was obtained by diluting polymer components (solids content: polymer (PI-1) 20 parts by mass, polymer (PA-1) 80 parts by mass), crosslinking agent (AD-1) 10.0 parts by mass, and adhesion aid (3-glycidyloxypropyltrimethoxysilane) 1 part by mass with NMP and BC to obtain a solution with a solids content of 4.0% by mass and a solvent composition ratio of NMP:BC = 70:30 (by mass). A liquid crystal alignment agent (AL-1) was prepared by filtering this solution through a pore size filter of 0.2 μm.

[0128] (2) Formation of liquid crystal alignment film by photoalignment method A glass substrate on which a flat electrode, an insulating layer, and a comb-shaped electrode are laminated in this order on one side, and a counter glass substrate without electrodes, were each coated with the liquid crystal alignment agent (AL-1) prepared in (1) above using a spin coater. After heating on an 80°C hot plate for 1 minute, the mixture was heated in a 230°C oven with nitrogen purging for 30 minutes to form a coating with an average thickness of 100 nm. The surface of this coating was exposed to 200 mJ / cm² of ultraviolet light containing linearly polarized emission lines at 254 nm using a Hg-Xe lamp. 2 The substrate was irradiated from the direction normal to the substrate to perform photoalignment. The photoaligned coating was then heat-treated by heating it in a 230°C oven with nitrogen purged for 30 minutes to form a liquid crystal alignment film.

[0129] (3) Manufacturing of FFS type liquid crystal display elements 。 English: On the outer circumference of one of the pair of substrates having the liquid crystal alignment film formed in (2) above, epoxy resin adhesive containing aluminum oxide spheres with a diameter of 3.5 μm was dispensed, leaving a liquid crystal injection port. Then, the surfaces of the pair of substrates having the liquid crystal alignment film were placed facing each other and pressed together so that the alignment processing directions of each substrate were opposite parallel, and the adhesive was heat-cured at 150°C for 1 hour. Next, negative nematic liquid crystal (Merck, MJ20195NCMP) 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 alignment during liquid crystal injection, it was heated at 120°C and then slowly cooled to room temperature. Next, polarizing plates were bonded to both outer surfaces of the substrate so that their polarization directions were orthogonal to each other and formed a 45° angle with the alignment processing direction of the liquid crystal alignment film, thereby manufacturing an FFS type liquid crystal display element.

[0130] (4) Evaluation of liquid crystal alignment (alignment uniformity) The liquid crystal display elements manufactured in (3) above were observed under a microscope at 50x magnification to check for the presence or absence of abnormal domains in the change in brightness when a 5V voltage was turned ON and OFF (applied and released). The evaluation was "good" if no abnormal domains were observed and "poor" if abnormal domains were observed. As a result, this embodiment was evaluated as "good".

[0131] (5) Evaluation of liquid crystal alignment properties (alignment control force) For the liquid crystal display elements manufactured in (3) above, the change in the liquid crystal azimuth angle was measured before and after 68 hours of operation under backlight illumination with an AC voltage of 11V using a birefringent (AXOMETRICS, AXOSTEP high-precision Müller matrix imaging polarimeter). The evaluation was as follows: a change in the liquid crystal azimuth angle of less than 0.1 degrees was considered "excellent," 0.1 degrees or more and less than 0.3 degrees was considered "good," and 0.3 degrees or more was considered "poor." The smaller the change in the liquid crystal azimuth angle, the less likely AC afterimages are to occur even when the liquid crystal display element is operated for a long time, and the better the liquid crystal alignment is considered to be. As a result, this embodiment was evaluated as "excellent."

[0132] (6) Evaluation of mechanical properties (resistance to keystroke testing) The liquid crystal display elements manufactured in (3) above were evaluated for their resistance to keystroke testing using a keystroke and sliding test machine manufactured by NTS Corporation. The evaluation was performed as follows: First, the liquid crystal cell was observed under a polarizing microscope with crossed nicols, and the number of bright spots (i.e., the number of bright spots before keystroke) was counted. Next, the liquid crystal cell was fixed on a fixed plate, and a keystroke indenter with a Shore hardness of 50 was repeatedly dropped from a height of 6.0 mm to apply a repeated load to the liquid crystal cell. When applying the load, the load was set to 250 gf, the number of repetitions to 100,000, and the speed to 2 Hz. After keystroke, the liquid crystal cell was observed again, and the number of bright spots (i.e., the number of bright spots after keystroke) was counted. The evaluation was based on whether the difference in the number of bright spots before and after keystroke was less than 50, and whether the difference was 50 or more, and whether the difference was "good". If the difference in the number of bright spots was less than 50, it can be said that the mechanical strength of the film against keystroke is good. As a result, this example received a "good" rating.

[0133] (7) Evaluation of mechanical properties (wear resistance) The liquid crystal alignment agent (AL-1) prepared in (1) above was applied to a glass substrate using a spin coater, heated on an 80°C hot plate for 1 minute, and then heated in a 230°C oven with nitrogen purging for 30 minutes to form a coating with an average thickness of 100 nm. The haze value of the coating was measured using a haze meter. Next, the coating was subjected to rubbing five times using a rubbing machine with a roll wrapped in cotton cloth, at a roll rotation speed of 1000 rpm, a stage movement speed of 3 cm / second, and a pile insertion length of 0.3 mm. After that, the haze value of the liquid crystal alignment film was measured using a haze meter, and the difference from the haze value before rubbing (haze change value) was calculated. If the haze value of the film before rubbing is Hz1 (%) and the haze value of the film after rubbing is Hz2 (%), the haze change value is expressed by the following formula (z-1). Haze change value (%) = Hz2 - Hz1 …(z-1) A haze change value of less than 0.2 in the liquid crystal alignment film was classified as "excellent," a value between 0.2 and 0.5 was classified as "good," and a value of 0.5 or higher was classified as "poor." A haze change value of less than 0.5 indicates high rubbing resistance and good mechanical properties of the film against surface abrasion. As a result, this example received a "good" evaluation.

[0134] (8) Evaluation of reliability An ECB-type liquid crystal display element was manufactured by forming a liquid crystal alignment film in the same manner as in (2) above, except that the substrate to which the liquid crystal alignment agent was applied was changed to a glass substrate having ITO electrodes, and performing the same operation as in (3) above. This liquid crystal display element was irradiated with light for 168 hours on a backlight using a CCFL as the light source. After light irradiation, a voltage of 1V was applied to the liquid crystal display element at 70°C for an application time of 60 microseconds and a span of 1670 milliseconds, and the voltage retention rate was measured 1670 milliseconds after the application was removed. Reliability was evaluated as follows: a voltage retention rate of 70% or more was "excellent," 60% or more was "good," and less than 60% was "poor." As a result, this embodiment was evaluated as "good." The voltage retention rate measuring device used was model "VHR-1" manufactured by Toyo Technica Co., Ltd.

[0135] [Examples 2-4, Comparative Examples 1-7] In Example 1 described above, a liquid crystal alignment agent was prepared in the same manner as in Example 1, except that the polymer and crosslinking agent contained in the liquid crystal alignment agent were changed as shown in Table 3 below. A liquid crystal alignment film was formed by photo-alignment, and FFS-type liquid crystal display elements and ECB-type liquid crystal display elements were manufactured and various evaluations were performed. The evaluation results are shown in Table 3 below.

[0136] [Example 5] In Example 1 described above, the polymer and crosslinking agent contained in the liquid crystal alignment agent were changed as shown in Table 3 below, and the exposure amount of linearly polarized ultraviolet light was set to 500 mJ / cm². 2 Except for a change, the liquid crystal alignment agent was prepared in the same manner as in Example 1, and a liquid crystal alignment film was formed by photo-alignment. FFS-type and ECB-type liquid crystal display elements were also manufactured and various evaluations were performed. The evaluation results are shown in Table 3 below.

[0137] [Example 6, Comparative Example 8, Comparative Example 9] In Example 5 described above, the liquid crystal alignment agent was prepared in the same manner as in Example 5, except that the polymer and crosslinking agent contained in the liquid crystal alignment agent were changed as shown in Table 3 below. A liquid crystal alignment film was formed by the photo-alignment method, and FFS-type liquid crystal display elements and ECB-type liquid crystal display elements were manufactured and various evaluations were performed. The evaluation results are shown in Table 3 below.

[0138] [Example 7: Rubbing-oriented FFS type liquid crystal display element] (1) Preparation of liquid crystal alignment agent A solution was obtained by diluting polymer components (solids content: polymer (PI-2) 20 parts by mass, polymer (PA-1) 80 parts by mass), crosslinking agent (AD-1) 10.0 parts by mass, and adhesion aid (3-glycidyloxypropyltrimethoxysilane) 1 part by mass with NMP and BC to obtain a solution with a solids content of 4.0% by mass and a solvent composition ratio of NMP:BC = 70:30 (by mass). A liquid crystal alignment agent (AL-16) was prepared by filtering this solution through a pore size filter of 0.2 μm.

[0139] (2) Formation of liquid crystal alignment film by rubbing method A glass substrate with a flat electrode, an insulating layer, and a comb-shaped electrode laminated in this order on one side, and a counter glass substrate without electrodes, were each coated with the liquid crystal alignment agent (AL-16) prepared in (1) above using a spin coater. The coated surfaces were heated on an 80°C hot plate for 1 minute, and then heated in a 230°C oven with nitrogen purging for 30 minutes to form a coating with an average thickness of 100 nm. The surface of this coating was subjected to two rubbing alignment treatments using a rubbing machine with a roll wrapped in nylon cloth, at a roll rotation speed of 1000 rpm, a stage movement speed of 30 mm / second, and a pile insertion length of 0.3 mm. The coating treated with this rubbing alignment treatment was ultrasonically cleaned in ultrapure water for 1 minute, and then dried in a 100°C oven for 10 minutes to form a liquid crystal alignment film.

[0140] (3) Manufacturing of FFS type liquid crystal display elements A pair of substrates having the liquid crystal alignment film formed in (2) above were used to manufacture an FFS-type liquid crystal display element in the same manner as in Example 1. (4) Evaluation of liquid crystal alignment (alignment uniformity) The FFS-type liquid crystal display element manufactured in (3) above was evaluated for liquid crystal alignment (alignment uniformity) in the same manner as in Example 1. As a result, this example received a "good" evaluation. (5) Evaluation of liquid crystal alignment properties (alignment control force) The FFS-type liquid crystal display element manufactured in (3) above was evaluated for liquid crystal alignment (alignment restricting force) in the same manner as in Example 1. As a result, this example received a "good" evaluation.

[0141] (6) Evaluation of mechanical properties (resistance to keystroke testing) The FFS-type liquid crystal display element manufactured in (3) above was evaluated for its mechanical properties (touch test resistance) in the same manner as in Example 1. As a result, this example received a "good" evaluation. (7) Evaluation of mechanical properties (wear resistance) Using the liquid crystal aligning agent (AL-16) prepared in (1) above, the mechanical properties (abrasion resistance) were evaluated in the same manner as in Example 1. As a result, the evaluation in this example was "good". (8) Evaluation of reliability Regarding the ECB type liquid crystal display device manufactured in the same manner as in Example 1, the reliability was evaluated in the same manner as in Example 1. As a result, the evaluation in this example was "excellent".

[0142] [Example 8, Comparative Examples 10 to 11] In Example 7 above, except that the polymer and crosslinking agent contained in the liquid crystal aligning agent were changed as shown in Table 3 below, a liquid crystal aligning agent was prepared in the same manner as in Example 7, and a liquid crystal alignment film was formed by the rubbing method. At the same time, an FFS type liquid crystal display device and an ECB type liquid crystal display device were manufactured and various evaluations were performed. The evaluation results are shown in Table 3 below.

[0143] [Table 3]

[0144] In Table 3, the mass ratio of each component of the liquid crystal aligning agent indicates the blending ratio (parts by mass) of each compound with respect to a total of 100 parts by mass of the polymer components used in the preparation of the liquid crystal aligning agent. In Examples 1 to 8 and Comparative Examples 2 to 11, the blending ratio of the crosslinking agent with respect to a total of 100 parts by mass of the polymer components is equimolar.

[0145] [Example 9: PSA type liquid crystal display device] (1) Preparation of liquid crystal aligning agent The polymer components (in terms of solid content: 95 parts by mass of polymer (PA-4), 5 parts by mass of polymer (PSQ-1)), and 11.3 parts by mass of crosslinking agent (AD-7) were diluted with NMP and BC to obtain a solution with a solid content concentration of 4.0% by mass and a solvent composition ratio of NMP:BC = 50:50 (mass ratio). This solution was filtered through a filter with a pore size of 0.2 μm to prepare a liquid crystal aligning agent (AL-20).

[0146] (2) Preparation of liquid crystal composition Liquid crystal composition (LC-1) was obtained by adding 5% by mass of a liquid crystalline compound represented by the following formula (L-1) and 0.3% by mass of a photopolymerizable compound represented by the following formula (L-2) to 10 g of nematic liquid crystal (Merck, MLC-6608) and mixing them. [ka]

[0147] (3) Formation of liquid crystal alignment film Two glass substrates, each having ITO electrodes patterned in a slit shape, were coated with the liquid crystal alignment agent (AL-14) prepared in (1) above using a spin coater. The coated substrates were then heated on an 80°C hot plate for 1 minute, followed by heating in a 230°C oven with nitrogen purging for 30 minutes to form a coating with an average thickness of 100 nm. This coating was ultrasonically cleaned in ultrapure water for 1 minute, and then dried in a 100°C oven for 10 minutes to form a liquid crystal alignment film. The electrode pattern used was the same type as the electrode pattern used in PSA mode.

[0148] (4) Manufacturing of PSA type liquid crystal display elements After applying epoxy resin adhesive containing 3.5 μm diameter aluminum oxide spheres to the outer circumference of one of the pair of substrates on which the liquid crystal alignment film was formed, leaving a liquid crystal injection port, an epoxy resin adhesive containing 3.5 μm diameter aluminum oxide spheres was dispensed using a dispenser. The two substrates were then overlapped with the liquid crystal alignment film facing each other and pressed together, and the adhesive was heat-cured at 150°C for 1 hour. Next, the liquid crystal composition (LC-1) prepared in (2) 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 to manufacture a liquid crystal cell. For the obtained liquid crystal cells, an AC voltage of 10V at a frequency of 60Hz was applied between the electrodes, and while the liquid crystal was in operation, ultraviolet light at a rate of 10,000 mJ / cm² was applied using an ultraviolet irradiation device with a metal halide lamp as the light source. 2The substrate was irradiated with the specified irradiation dose. This irradiation dose was measured using a light meter that measures at a wavelength of 365 nm. Next, a PSA-type liquid crystal display element was manufactured by bonding polarizing plates to both outer surfaces of the substrate such that their polarization directions were perpendicular to each other and formed a 45° angle with the alignment processing direction of the liquid crystal alignment film.

[0149] (5) Evaluation of liquid crystal alignment (alignment uniformity) The PSA-type liquid crystal display element manufactured in (4) above was evaluated for liquid crystal alignment (alignment uniformity) in the same manner as in Example 1. As a result, this example received a "good" evaluation.

[0150] (6) Evaluation of mechanical properties (resistance to keystroke testing) The PSA-type liquid crystal display element manufactured in (4) above was evaluated for its mechanical properties (touch test resistance) in the same manner as in Example 1. As a result, this example received a "good" evaluation.

[0151] (7) Evaluation of reliability The reliability of the PSA-type liquid crystal display element manufactured in (4) above was evaluated in the same manner as in Example 1. As a result, this example received an "excellent" rating.

[0152] [Example 10: Photo-aligned VA-type liquid crystal display element] (1) Preparation of liquid crystal alignment agent A solution was obtained by diluting polymer components (based on solid content: polymer (PA-5) 85 parts by mass, polymer (PMI-1) 10 parts by mass) and crosslinking agent (AD-7) 11.3 parts by mass with NMP and BC to obtain a solution with a solid content concentration of 4.0% by mass and a solvent composition ratio of NMP:BC = 50:50 (by mass). A liquid crystal alignment agent (AL-21) was prepared by filtering this solution through a filter with a pore size of 0.2 μm.

[0153] (2) Formation of liquid crystal alignment film by photoalignment method The liquid crystal alignment agent (AL-21) prepared in (1) above was applied to the electrode surfaces of two glass substrates having ITO electrodes using a spin coater, heated on an 80°C hot plate for 1 minute, and then heated in a 230°C oven with nitrogen purging for 30 minutes to form a coating with an average thickness of 100 nm. The surface of this coating was exposed to 20 mJ / cm² of linearly polarized ultraviolet light containing a 313 nm emission line using a Hg-Xe lamp. 2 A liquid crystal alignment film was formed by irradiating the substrate with light from a direction tilted 40° from the substrate normal and performing a photo-alignment treatment.

[0154] (3) Manufacturing of VA-type liquid crystal display elements After applying epoxy resin adhesive containing 3.5 μm diameter aluminum oxide spheres to the outer circumference of one of the substrates prepared in (2) above, leaving a liquid crystal injection port, the surfaces of the two substrates with liquid crystal alignment films were placed facing each other and pressed together so that the projection directions of the ultraviolet light axes of each substrate onto the substrate surface were opposite parallel, and the adhesive was heat-cured at 150°C for 1 hour. Next, negative nematic liquid crystal (Merck MLC-6608) was filled into the gap between the substrates through the liquid crystal injection port, and then the liquid crystal injection port was sealed with epoxy adhesive. Furthermore, to eliminate the flow orientation during liquid crystal injection, it was heated to 120°C and then slowly cooled to room temperature. Next, polarizing plates were bonded to both outer surfaces of the substrate so that their polarization directions were perpendicular to each other and formed a 45° angle with the orientation processing direction of the liquid crystal alignment film, thereby manufacturing a VA-type liquid crystal display element.

[0155] (4) Evaluation of liquid crystal alignment (alignment uniformity) The VA-type liquid crystal display element manufactured in (3) above was evaluated for liquid crystal alignment (alignment uniformity) in the same manner as in Example 1. As a result, this example received a "good" evaluation.

[0156] (5) Evaluation of mechanical properties (resistance to keystroke testing) The VA-type liquid crystal display element manufactured in (3) above was evaluated for its mechanical properties (touch test resistance) in the same manner as in Example 1. As a result, this example received a "good" evaluation.

[0157] (6) Reliability evaluation Regarding the VA type liquid crystal display element manufactured in (3) above, reliability evaluation was carried out in the same manner as in Example 1. As a result, the evaluation in this example was "excellent".

[0158]

Table 4

[0159] In Table 4, the mass ratio of each component of the liquid crystal alignment agent indicates the blending ratio (parts by mass) of each compound with respect to a total of 100 parts by mass of the polymer components used in the preparation of the liquid crystal alignment agent.

[0160] [Examples 11 to 14, Comparative Example 12] In Example 1 above, except that the polymer and crosslinking agent contained in the liquid crystal alignment agent were changed as shown in Table 5 below, a liquid crystal alignment agent was prepared in the same manner as in Example 1, and a liquid crystal alignment film was formed by the photo-alignment method. At the same time, an FFS type liquid crystal display element and an ECB type liquid crystal display element were manufactured and various evaluations were carried out. The evaluation results are shown in Table 5 below.

Table 5

[0161] As shown in Tables 3 to 5, the liquid crystal alignment agents of Examples 1 to 14 containing the polymer (P) and the compound (C) all had "excellent" or "good" liquid crystal alignment properties, mechanical properties, and reliability of the liquid crystal display element, and various properties were excellent. In contrast, the liquid crystal alignment agents of Comparative Examples 1 to 12 that did not contain the polymer (P) or the compound (C) had at least one of "poor" liquid crystal alignment properties and mechanical properties of the liquid crystal display element, and were inferior to the examples.

[0162] In Examples 1 to 14, the mechanism by which the mechanical properties of the liquid crystal display elements were improved is not clear, but it is presumed to be as follows: Polymers (PI-1, PI-2) and polymers (PA-1 to PA-5) all have numerous carboxyl groups in their molecules, and it is thought that they form intermolecular crosslinking structures (esterification) with the reactive functional groups (hydroxyl groups or their acetal protected forms) in compound (C), which functions as a crosslinking agent.

[0163] Compound (C) has at least some of its highly polar hydroxyl groups protected by an acetal structure, resulting in lower polarity (hydrophobicity) compared to the crosslinking agents used in Comparative Examples 2, 4-7. Therefore, it is presumed that its surface free energy is lower than that of polymer (P) contained in the liquid crystal alignment agent, and that the crosslinking agent is more likely to be unevenly distributed on the film surface (air interface side) when forming a liquid crystal alignment film.

[0164] In addition, compound (C) has thermal latent properties, and it is thought that the protecting group gradually detaches due to heat, causing crosslinking to proceed. Therefore, when forming a liquid crystal alignment film, phase separation from the polymer may proceed before compound (C) reacts with the polymer, potentially causing compound (C) to be unevenly distributed near the film surface. On the other hand, the crosslinking agents used in Comparative Examples 2, 4-7 are highly polar and easily compatible with polymers, and the crosslinking agent used in Comparative Example 3 has low thermal stability of its protecting group, so it is presumed that uneven distribution of the crosslinking agent is less likely to occur as it rapidly forms crosslinks with the polymer during the firing process.

[0165] The resistance of a liquid crystal display element to keystroke tests reflects the abrasion resistance of the film surface. In Examples 1 to 14, the uneven distribution of the crosslinking agent on the film surface promoted crosslinking near the film surface, resulting in a positionally selective improvement in mechanical strength. Therefore, it is believed that the mechanical properties of the liquid crystal alignment film were improved compared to the crosslinking agents used in Comparative Examples 2 to 7. When the abrasion resistance of the film surface is low, various stresses applied to the liquid crystal display element (glass polishing, vibration, keystrokes / finger presses, etc.) cause the liquid crystal alignment films to rub against each other and wear down, resulting in liquid crystal alignment defects in the worn areas and minute bright spot defects due to wear particles.

[0166] Furthermore, in Examples 3, 4, 6, and 8, a crosslinking agent having an amino group protected by a Boc group was included as compound (C), and the reliability of the liquid crystal display element was "excellent," and particularly outstanding. The mechanism by which reliability was improved is not clear, but it is presumed to be as follows.

[0167] Liquid crystal compositions having alkenyl structures, etc., as liquid crystals are known to undergo oxidative decomposition upon light irradiation, producing acidic decomposition products such as formic acid, which can degrade the electrical properties and reliability of liquid crystal display elements. Compound (C), which further has -NH- protected by a Boc group, is presumed to be able to capture acidic decomposition products derived from liquid crystals because it is deprotected by heat to produce -NH- (a basic functional group). Furthermore, when using a photo-alignment method that utilizes the photodecomposition reaction of the cyclobutane ring, it is possible that the amino group generated by heat will form a crosslinked structure through a Michael addition reaction with the maleimide derivative of the photodecomposition product. It is presumed that the crosslinking of the polymer of the liquid crystal alignment film by the crosslinking agent will suppress swelling of the film due to liquid crystals, as well as suppress the transfer of impurity ions and other substances incorporated into the film, thereby contributing to an improvement in voltage retention.

[0168] On the other hand, the liquid crystal alignment agent of Comparative Example 12 contained compound (C) but did not contain polymer (P) having a carboxyl group, and the keying test resistance of the liquid crystal display element and the abrasion resistance of the liquid crystal alignment film were "poor". This result is thought to be due to the lack of reaction sites in the polymer that form a crosslinking reaction with compound (C), and therefore the improvement effect on mechanical properties was not observed.

[0169] Based on the above, it is inferred that a liquid crystal alignment agent containing polymer (P) and compound (C) can improve the mechanical properties of the liquid crystal alignment film while maintaining good liquid crystal alignment, resulting in a highly reliable liquid crystal element.

Claims

1. A polymer (P) having a carboxyl group, "-OX" １ The base represented by " (where X １ It has multiple atoms (which are hydrogen atoms or thermally leaving groups) within one molecule, and also has "-OX １ One or more of the bases represented by " are the X １ A compound (C) having a monovalent group having a tetrahydropyran ring structure or a tetrahydrofuran ring structure, A liquid crystal alignment agent containing the following:

2. The liquid crystal alignment agent according to claim 1, wherein the compound (C) has a substructure represented by the following formula (1). 【Chemistry 1】 (In formula (1), X １ R is a hydrogen atom or a thermally leaving group. １ａ R is a hydrogen atom or a monovalent organic group having 1 to 4 carbon atoms. １ｂ and R １ｃ Each of these is independently a hydrogen atom or a monovalent organic group having 1 to 8 carbon atoms. (* indicates a bond.)

3. The liquid crystal alignment agent according to claim 1, wherein the compound (C) is a compound represented by the following formula (2). 【Chemistry 2】 (In formula (2), X １ is a hydrogen atom or a thermally desorbable group. However, the four Xs １ in the formula are the same or different, and one or more of the four Xs １ are monovalent groups having a tetrahydropyran ring structure or a tetrahydrofuran ring structure. R ２ is a divalent organic group.)

4. The aforementioned compound (C) is "-NY １ The base represented by - (where Y １ The liquid crystal alignment agent according to claim 1, wherein ( is a thermally desorbable group).

5. The aforementioned X １ The liquid crystal alignment agent according to claim 1, wherein is a hydrogen atom, a substituted or unsubstituted 2-tetrahydropyranyl group, or a substituted or unsubstituted 2-tetrahydrofuranyl group.

6. The liquid crystal alignment agent according to claim 1, wherein the polymer (P) is at least one selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide.

7. The liquid crystal alignment agent according to claim 6, wherein the polymer (P) comprises a polymer having at least one selected from the group consisting of a substructure represented by the following formula (3), a substructure represented by the following formula (4), and a substructure represented by the following formula (5). 【Transformation 3】 (In formulas (3) to (5), Z １ Z is a tetravalent organic group. ２ Z is a divalent organic group. ３ R is a divalent organic group having a carboxyl group. ３ and R ４ These are each independently monovalent organic groups.

8. The liquid crystal alignment agent according to claim 1, wherein the content of compound (C) is 0.1 to 50 parts by mass with respect to 100 parts by mass of the total polymer components contained in the liquid crystal alignment agent.

9. A liquid crystal alignment film formed using the liquid crystal alignment agent described in any one of claims 1 to 8.

10. A liquid crystal element comprising the liquid crystal alignment film described in claim 9.

11. A polymer (P) having a carboxyl group, "-OX" １ The base represented by " (where X １ It has multiple atoms (which are hydrogen atoms or thermally leaving groups) within one molecule, and also has "-OX １ One or more of the bases represented by " are the X １ A compound (C) having a monovalent group having a tetrahydropyran ring structure or a tetrahydrofuran ring structure, A thermosetting composition containing [a specific substance].

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