JP2023133134A - Liquid crystal aligning agent, liquid crystal alignment film, liquid crystal element, thermosetting composition, and compound - Google Patents

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

The present invention relates to a liquid crystal alignment agent, a liquid crystal alignment film, a liquid crystal element, a thermosetting composition, and a compound.

A liquid crystal element includes a liquid crystal alignment film that has a function of aligning liquid crystal molecules in a liquid crystal layer in a certain direction. A liquid crystal aligning film is generally formed on a substrate by applying a liquid crystal aligning agent in which a polymer component is dissolved in an organic solvent to the substrate surface, and preferably heating the liquid crystal aligning agent.

In recent years, large-screen, high-definition liquid crystal televisions have become mainstream, and small display terminals such as smartphones and tablet PCs have become more popular, and the demand for higher quality liquid crystal elements is higher than ever. Therefore, various liquid crystal aligning agents have been proposed in order to improve the performance of the liquid crystal aligning film and to make various characteristics of the liquid crystal element excellent (see, for example, Patent Document 1). Patent Document 1 discloses that a liquid crystal aligning agent contains a compound having a structure in which a methylol group is bonded to an aromatic ring together with polyimide or a polyimide precursor.

International Publication No. 2010/074269

Liquid crystal elements are used not only in conventional display terminals such as personal computers, but also in various applications such as liquid crystal televisions, car navigation systems, mobile phones, smartphones, information displays, retardation films, and light control films. used in Furthermore, in recent years, the mainstream of liquid crystal devices used in smartphones and automobiles is a touch panel type, which is susceptible to external forces caused by the user's keystroke operations. From the perspective of improving the quality and reliability of liquid crystal elements, liquid crystal elements should maintain good liquid crystal orientation, which is a basic property, while being less susceptible to deterioration in display quality due to external forces, and having mechanical properties ( Specifically, it is required to have good keystroke durability and abrasion resistance.

Further, as the applications of liquid crystal elements expand, they are sometimes used under conditions in which the liquid crystal panel is irradiated with a backlight for a longer period of time due to continuous driving for a longer period of time than conventionally. Liquid crystal elements are required to be highly reliable and resistant to deterioration in performance even under such usage environments.

The present invention was made in view of the above-mentioned problems, and an object of the present invention is to provide a liquid crystal aligning agent that can maintain good liquid crystal alignment, have good mechanical properties, and obtain a highly reliable liquid crystal element. The main purpose is

According to the present invention, the following means are provided.

<1> A polymer (P) having a carboxyl group and a plurality of groups represented by “-OX ¹ ” (however, X ¹ is a hydrogen atom or a thermally releasable group) in one molecule. , and one or more of the groups represented by "-OX ¹ " is a compound (C) in which X ¹ is a monovalent group having a tetrahydropyran ring structure or a tetrahydrofuran ring structure. agent.

（式（１）中、Ｘ^１は水素原子又は熱脱離性基である。Ｒ^１ａは水素原子又は炭素数１～４の１価の有機基である。Ｒ^１ｂ及びＲ^１ｃは、それぞれ独立して、水素原子又は炭素数１～８の１価の有機基である。「＊」は結合手を表す。） <2> The liquid crystal aligning agent according to <1> above, wherein the compound (C) has a partial structure represented by the following formula (1).

(In formula (1), X ¹ is a hydrogen atom or a thermally releasable group ^. R ^1a is a hydrogen atom or a monovalent organic group having 1 to 4 carbon atoms ^. It is a hydrogen atom or a monovalent organic group having 1 to 8 carbon atoms. "*" represents a bond.)

（式（２）中、Ｘ^１は水素原子又は熱脱離性基である。ただし、式中の４個のＸ^１は同一又は異なり、４個のＸ^１のうち１個以上はテトラヒドロピラン環構造又はテトラヒドロフラン環構造を有する１価の基である。Ｒ^２は２価の有機基である。） <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).

(In formula (2), X ¹ is a hydrogen atom or a thermally releasable group. However, the four X ^1s in the formula are the same or different, and one or more of the four X ^1s is a tetrahydropyran ring. ( ^R2 is a divalent organic group.)

<4> Any one of <1> to <3> above, wherein the compound (C) has a group represented by "-NY ¹ -" (wherein Y ¹ is a thermally releasable group) liquid crystal alignment agent.
<5> The X ¹ is a hydrogen atom, a substituted or unsubstituted 2-tetrahydropyranyl group, or a substituted or unsubstituted 2-tetrahydrofuranyl group, according to any one of <1> to <4> above. liquid crystal alignment agent.
<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.

（式（３）～式（５）中、Ｚ^１は４価の有機基である。Ｚ^２は２価の有機基である。Ｚ^３は、カルボキシ基を有する２価の有機基である。Ｒ^３及びＲ^４は、それぞれ独立して１価の有機基である。） <7> The polymer (P) is selected from the group consisting of a partial structure represented by the following formula (3), a partial structure represented by the following formula (4), and a partial structure represented by the following formula (5). The liquid crystal aligning agent as described in said <6> containing the polymer which has at least 1 type selected.

(In formulas (3) to (5), Z ¹ is a tetravalent organic group. Z ² is a divalent organic group. Z ³ is a divalent organic group having a carboxy group. R ³ and R ⁴ are each independently a monovalent organic group.)

<8> The above <1> to <7, wherein the content ratio of the compound (C) is 0.1 to 50 parts by mass with respect to a total of 100 parts by mass of the polymer components contained in the liquid crystal aligning agent. >The liquid crystal aligning agent according to any one of the above.
<9> A liquid crystal aligning film formed using the liquid crystal aligning agent according to any one of <1> to <8> above.
<10> A liquid crystal element comprising the liquid crystal alignment film according to <9> above.

<11> A polymer (P) having a carboxyl group and a plurality of groups represented by "-OX ¹ " (wherein X ¹ is a hydrogen atom or a thermally releasable group) in one molecule. , and one or more of the groups represented by "-OX ¹ " is a thermosetting compound (C) in which X ¹ is a monovalent group having a tetrahydropyran ring structure or a tetrahydrofuran ring structure. sexual composition.
<12> A compound represented by the above formula (2).

According to the liquid crystal aligning agent of the present invention, it is possible to obtain a liquid crystal element with good mechanical properties and high reliability while maintaining good liquid crystal alignment.

A diagram showing a ¹ H-NMR spectrum of compound (AD-1). A diagram showing a ¹ H-NMR spectrum of compound (AD-2). A diagram showing a ¹ H-NMR spectrum of compound (AD-7-1). A diagram showing a ¹ H-NMR spectrum of compound (AD-8).

《Liquid crystal alignment agent》
Each component contained in the liquid crystal aligning agent of the present disclosure and other components optionally blended as necessary will be explained below. In addition, unless otherwise mentioned, each component may be used alone or in combination of two or more.

Here, in this specification, the term "hydrocarbon group" includes a chain hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. The term "chain hydrocarbon group" refers to a straight chain hydrocarbon group and a branched hydrocarbon group that do not contain a cyclic structure in the main chain and are composed only of a chain structure. However, the chain hydrocarbon group may be saturated or unsaturated. "Alicyclic hydrocarbon group" means a hydrocarbon group containing only an alicyclic hydrocarbon structure as a ring structure and not containing an aromatic ring structure. However, the alicyclic hydrocarbon group does not need to be composed only of an alicyclic hydrocarbon structure, and includes those having a chain structure as a part thereof. "Aromatic hydrocarbon group" means a hydrocarbon group containing an aromatic ring structure as a ring structure. However, the aromatic ring hydrocarbon group does not need to be composed only of an aromatic ring structure, and may include a chain structure or an alicyclic hydrocarbon structure as a part thereof. "Aromatic ring" is meant to include aromatic hydrocarbon rings and aromatic heterocycles. The term "organic group" refers to an atomic group obtained by removing any hydrogen atoms from a carbon-containing compound (ie, an organic compound).

The ``main chain'' of a polymer refers to the ``trunk'' portion of the polymer consisting of the longest chain of atoms. It is permissible for this "trunk" portion to include 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 chain" refers to a portion branched from the "trunk" of the polymer. The term "tetracarboxylic acid derivative" includes tetracarboxylic dianhydride, tetracarboxylic diester, and tetracarboxylic diester dihalide. "(Meth)acrylic" includes acrylic and methacrylic.

The liquid crystal aligning agent of the present disclosure includes a polymer (P) having a carboxyl group and a group represented by “-OX ¹ ” (however, X ¹ is a hydrogen atom or a thermally releasable group) in one molecule. and a compound (C) having a plurality of compounds. Hereinafter, components contained in the liquid crystal aligning agent of the present disclosure and optionally blended components will be explained.

<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 the crosslinking reaction with the compound (C), the polymer (P) is a monomer having a carboxy group or an acid anhydride group. It is preferable to include a structural unit derived from a body. Among them, from the viewpoint of obtaining a liquid crystal element with excellent liquid crystal orientation and reliability, the polymer (P) is preferably at least one selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, and addition polymer. Preferably, it is at least one selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide.

The amount of carboxy groups possessed by the polymer (P) is preferably 0.1 mmol/g or more, more preferably 1.0 mmol/g or more, and 2.0 mmol from the viewpoint of sufficiently imparting reactivity with the compound (C). /g or more is more preferable.

When the polymer (P) is an addition polymer, examples of the addition polymer include (meth)acrylic polymers, styrene polymers, maleimide polymers, styrene-maleimide copolymers, etc. . For the addition polymer having a carboxy group, for example, an unsaturated carboxylic acid such as (meth)acrylic acid, α-ethyl acrylic acid, maleic acid, fumaric acid, or vinylbenzoic acid may be used as a monomer having a carboxy group. It can be obtained by

（式（３）～式（５）中、Ｚ^１は４価の有機基である。Ｚ^２は２価の有機基である。Ｚ^３は、カルボキシ基を有する２価の有機基である。Ｒ^３及びＲ^４は、それぞれ独立して１価の有機基である。） When the polymer (P) is at least one member selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide, the polymer (P) has a partial structure represented by the following formula (3), the following formula ( It is preferable to have at least one kind selected from the group consisting of the partial structure represented by 4) and the partial structure represented by the following formula (5), and has at least the partial structure represented by the following formula (3). It is more preferable.

(In formulas (3) to (5), Z ¹ is a tetravalent organic group. Z ² is a divalent organic group. Z ³ is a divalent organic group having a carboxy group. R ³ and R ⁴ are each independently a monovalent organic group.)

In the above formula (3), the tetravalent organic group represented by Z ¹ is a partial structure derived from tetracarboxylic dianhydride. Examples of the tetracarboxylic dianhydride include aliphatic tetracarboxylic dianhydride and aromatic tetracarboxylic dianhydride. Examples of aliphatic tetracarboxylic dianhydrides include chain tetracarboxylic dianhydrides and alicyclic tetracarboxylic dianhydrides. As the tetracarboxylic dianhydride used in the synthesis of the polymer (P), known compounds used in the synthesis of polyamic acids, polyamic acid esters, and polyimides can be used.

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

In the above formula (3), the divalent organic group represented by Z ² is a group derived from diamine. In addition, in the above formulas (4) and (5), the divalent organic group represented by Z ³ is a group derived from a diamine having a carboxy group (hereinafter also referred to as "carboxy group-containing diamine"). .

The carboxy group in Z ³ may be bonded to a chain structure or may be bonded to a ring structure. The carboxy group in Z ³ is preferably bonded directly to the aromatic ring structure or via a divalent linking group, and more preferably directly bonded to the aromatic ring structure. When a carboxyl group is bonded to an aromatic ring structure via a divalent linking group, examples of the divalent linking group include an alkanediyl group having 1 to 3 carbon atoms and an alkanediyl group having 2 to 4 carbon atoms. A divalent group in which any methylene group in is replaced with -O-, -CO-, -COO-, -NR ⁶ - or -CO-NR ⁶ - (R ⁶ is a hydrogen atom or a monovalent organic (base) etc. The number of carboxy groups that Z ³ has is not particularly limited, and is, for example, 1 to 4, preferably 1 or 2.

（式中、「＊」は結合手を表す。） Specific examples of the divalent organic group represented by Z ³ include groups represented by the following formula.

(In the formula, "*" represents a bond.)

When the polymer (P) contains a partial structure derived from a carboxyl group-containing diamine, the content thereof may be 2 mol% or more based on the total structural units derived from the diamine contained in the polymer (P). It is preferably 5 mol% or more, more preferably 10 mol% or more. Further, the content of the partial structure derived from the carboxyl group-containing diamine is preferably 80 mol% or less, and preferably 60 mol% or less, based on the total structural units derived from the diamine that the polymer (P) has. It is more preferable. By setting the content ratio of the partial structure derived from the carboxyl group-containing diamine within the above range, the mechanical strength of the liquid crystal alignment film and the reliability of the liquid crystal element can be further improved by reaction with the compound (C).

When the polymer (P) has a partial structure represented by the above formula (3), the diamine constituting the polymer (P) may be only a carboxyl group-containing diamine, or a combination of a carboxyl group-containing diamine and other diamines. It may be used in combination with diamines or only other diamines. In addition, when the polymer (P) has a partial structure represented by the above formula (4) or a partial structure represented by the above formula (5), the diamine constituting the polymer (P) is a carboxy group-containing diamine It may be used alone or in combination with a carboxyl group-containing diamine and another diamine. Other diamines are compounds that do not have carboxy groups. As other diamines, known compounds used in the synthesis of polyamic acids, polyamic acid esters, and polyimides can be used.

Other diamines include aliphatic diamines, aromatic diamines, diaminoorganosiloxanes, and the like. Aliphatic diamines include chain diamines and alicyclic diamines. Specific examples of other diamines include metaxylylene diamine, hexamethylene diamine, and the like as chain diamines. Examples of the alicyclic diamine include 1,4-diaminocyclohexane and 4,4'-methylenebis(cyclohexylamine).

（式中の「Ｂｏｃ」はｔｅｒｔ－ブトキシカルボニル基を表す。）
で表される窒素含有ジアミン等の主鎖型ジアミン；
ヘキサデカノキシ－２，４－ジアミノベンゼン、オクタデカノキシ－２，４－ジアミノベンゼン、オクタデカノキシ－２，５－ジアミノベンゼン、コレスタニルオキシ－３，５－ジアミノベンゼン、コレステリルオキシ－３，５－ジアミノベンゼン、コレスタニルオキシ－２，４－ジアミノベンゼン、コレステリルオキシ－２，４－ジアミノベンゼン、３，５－ジアミノ安息香酸コレスタニル、３，５－ジアミノ安息香酸コレステリル、３，５－ジアミノ安息香酸ラノスタニル、３，６－ビス（４－アミノベンゾイルオキシ）コレスタン、３，６－ビス（４－アミノフェノキシ）コレスタン、４－（４’－トリフルオロメトキシベンゾイロキシ）シクロヘキシル－３，５－ジアミノベンゾエート、１，１－ビス（４－（（アミノフェニル）メチル）フェニル）－４－ブチルシクロヘキサン、３，５－ジアミノ安息香酸＝５ξ－コレスタン－３－イル、下記式（Ｅ－１）

（式（Ｅ－１）中、Ｘ^I及びＸ^IIは、それぞれ独立して、単結合、－Ｏ－、＊－ＣＯＯ－又は＊－ＯＣＯ－（ただし、「＊」はジアミノフェニル基側との結合手を示す。）である。Ｒ^Ｉは、炭素数１～３のアルカンジイル基である。Ｒ^ＩＩは、単結合又は炭素数１～３のアルカンジイル基である。Ｒ^ＩＩＩは、炭素数１～２０のアルキル基、アルコキシ基、フルオロアルキル基、又はフルオロアルコキシ基である。ａは０又は１である。ｂは０～３の整数である。ｃは０～２の整数である。ｄは０又は１である。ただし、１≦ａ＋ｂ＋ｃ≦３である。）
で表される化合物等の側鎖型ジアミン等が挙げられる。ジアミノオルガノシロキサンとしては、１，３－ビス（３－アミノプロピル）－テトラメチルジシロキサン等が挙げられる。 Examples of 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), bis[2-(4-aminophenyl)ethyl]hexanedioic acid, 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, below formula

(“Boc” in the formula represents a tert-butoxycarbonyl group.)
Main chain diamine such as nitrogen-containing diamine represented by;
Hexadecanoxy-2,4-diaminobenzene, octadecanoxy-2,4-diaminobenzene, octadecanoxy-2,5-diaminobenzene, cholestanyloxy-3,5-diaminobenzene, cholesteryloxy-3,5-diaminobenzene, cholestanil Oxy-2,4-diaminobenzene, cholesteryloxy-2,4-diaminobenzene, cholestanyl 3,5-diaminobenzoate, cholesteryl 3,5-diaminobenzoate, lanostanil 3,5-diaminobenzoate, 3,6-diaminobenzoate Bis(4-aminobenzoyloxy)cholestane, 3,6-bis(4-aminophenoxy)cholestane, 4-(4'-trifluoromethoxybenzoyloxy)cyclohexyl-3,5-diaminobenzoate, 1,1-bis (4-((aminophenyl)methyl)phenyl)-4-butylcyclohexane, 3,5-diaminobenzoic acid = 5ξ-cholestan-3-yl, following formula (E-1)

(In formula (E-1), X ^I and X ^II are each independently a single bond, -O-, *-COO- or *-OCO- (however, "*" is a bond with the diaminophenyl group side) ). R ^I is an alkanediyl group having 1 to 3 carbon atoms. R ^II is a single bond or an alkanediyl group having 1 to 3 carbon atoms. R ^III is an alkanediyl group having 1 to 3 carbon atoms. 1 to 20 alkyl groups, alkoxy groups, fluoroalkyl groups, or fluoroalkoxy groups. a is 0 or 1. b is an integer of 0 to 3. c is an integer of 0 to 2. d is 0 or 1. However, 1≦a+b+c≦3.)
Examples include side chain diamines such as the compound represented by: Examples of the diaminoorganosiloxane include 1,3-bis(3-aminopropyl)-tetramethyldisiloxane.

Examples of the compound represented by formula (E-1) include compounds represented by each of the following formulas (E-1-1) to (E-1-4).

[Synthesis of polymer (P)]
・Polyamic acid When the polymer (P) is a polyamic acid, the polyamic acid (hereinafter also referred to as "polyamic acid (P)") is prepared by adjusting the molecular weight of a tetracarboxylic dianhydride and a diamine as necessary. It can be obtained by reacting with an agent.

In the synthesis reaction of polyamic acid (P), the ratio of tetracarboxylic dianhydride and diamine used is 0.2 to 0.2 to 1 equivalent of the amino group of the diamine. A ratio of 2 equivalents is preferred. 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 naphthylisocyanate. can be mentioned. The proportion of the molecular weight regulator used is preferably 20 parts by mass or less based on the total of 100 parts by mass of the tetracarboxylic dianhydride and diamine used.

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 the organic solvent used in the reaction include aprotic polar solvents, phenol solvents, alcohol solvents, ketone solvents, ester solvents, ether solvents, halogenated hydrocarbons, hydrocarbons, etc. . Among these, N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphorotriamide, m-cresol, xylenol and halogen It is possible to use one or more selected from the group consisting of chemical phenols as a reaction solvent, or to use a mixture of one or more of these and other organic solvents (for example, butyl cellosolve, diethylene glycol diethyl ether, etc.). preferable. The amount of organic solvent used is preferably such that the total amount of the tetracarboxylic dianhydride and diamine compound is 0.1 to 50% by mass based on the total amount of the reaction solution.

When a polymer solution obtained by dissolving polyamic acid (P) is obtained by the above polymerization, this polymer solution may be used as it is for preparing a liquid crystal aligning agent, and the polyamic acid (P) contained in the polymer solution may be used as is. may be isolated and then used for preparing a liquid crystal aligning agent.

- Polyamic acid ester When the polymer (P) is a polyamic acid ester, the polyamic acid ester is a group consisting of a partial structure represented by the above formula (3) and a partial structure represented by the above formula (4). Examples include polymers having at least one selected from the following. Here, the monovalent organic group represented by R ³ or R ⁴ in the above formula (4) includes a monovalent hydrocarbon group having 1 to 10 carbon atoms, a photo-alignable group, and the like. The polyamic acid ester as the polymer (P) can be produced by, for example, [I] a method of reacting a polyamic acid (P) with an esterifying agent, [II] a method of reacting a tetracarboxylic diester with a diamine, [III] It can be obtained by a method of reacting a tetracarboxylic acid diester dihalide with a diamine, etc. The polyamic acid ester may have only an amic acid ester structure, or may be a partially esterified product in which an amic acid structure and an amic acid ester structure coexist. The reaction solution obtained by dissolving the polyamic acid ester may be used as it is for preparing a liquid crystal aligning agent. Alternatively, the polyamic acid ester contained in the reaction solution may be isolated and the isolated polyamic acid ester may be used for preparing a liquid crystal aligning agent.

- 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 ring-closing polyamic acid (P) and imidizing it. . The imidization rate of polyimide (P) is preferably 20 to 90%, more preferably 30 to 85%. The imidization rate is the ratio of the number of imide ring structures to the total number of amic acid structures and the number of imide ring structures of polyimide, expressed as a percentage.

Dehydration and ring closure of polyamic acid (P) is preferably carried out by dissolving polyamic acid (P) in an organic solvent, adding a dehydrating agent and a dehydration ring closure catalyst to this solution, and heating as necessary. In this method, as the dehydrating agent, for example, acid anhydrides such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride can be used. The amount of the dehydrating agent used is preferably 0.01 to 20 mol per 1 mol of the amic acid structure of the polyamic acid (P). As the dehydration ring-closing catalyst, for example, tertiary amines such as pyridine, collidine, lutidine, and triethylamine can be used. The amount of the dehydration ring-closing catalyst used is preferably 0.01 to 10 moles per mole of the dehydrating agent used.

Examples of the organic solvent used in the dehydration ring closure reaction include the organic solvents exemplified as those used in the synthesis of polyamic acid (P). The reaction temperature of the dehydration ring closure reaction is preferably 0 to 180°C. The reaction time is preferably 1.0 to 120 hours. In addition, the reaction solution containing polyimide (P) may be used for preparation of a liquid crystal aligning agent as it is. Alternatively, polyimide (P) may be isolated from the reaction solution, and the isolated polyimide (P) may be used for preparing a liquid crystal aligning agent. Polyimide (P) can also be obtained by dehydration ring closure of polyamic acid ester.

The solution viscosity of the polymer (P) is preferably one having a solution viscosity of 10 to 800 mPa·s, and 15 to 500 mPa·s when the solution has a concentration of 10% by mass. It is more preferable. Note that the solution viscosity (mPa・s) is for a polymer solution with a concentration of 10% by mass prepared using a good solvent for the polymer (P) (for example, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.). This is a value measured at 25°C using an E-type rotational viscometer.

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

The content ratio of the polymer (P) in the liquid crystal aligning agent is preferably 50% by mass or more based on the total amount of solid content contained in the liquid crystal aligning agent (i.e., the total mass of components other than the solvent of the liquid crystal aligning agent). , more preferably 60% by mass or more, and still more preferably 70% by mass or more.

<Compound (C)>
Compound (C) has a plurality of groups represented by "-OX ¹ " (wherein X ¹ is a hydrogen atom or a thermally releasable group) in one molecule. In compound (C), one or more of the groups represented by "-OX ¹ " is a monovalent group in which X ¹ has a tetrahydropyran ring structure or a tetrahydrofuran ring structure.

[About the group represented by “-OX ¹ ”]
The thermally releasable group represented by X ¹ is a substituent that is removed by heat during production of the liquid crystal aligning film and replaced with a hydrogen atom. Examples of the thermally releasable ^group represented by Ether type thermally releasable group; acetal type thermally releasable group such as an alkoxyalkyl group having 2 to 6 carbon atoms, a substituted or unsubstituted 2-tetrahydrofuranyl group, a substituted or unsubstituted 2-tetrahydropyranyl group; Acyl thermally releasable groups such as acetyl group and benzoyl group; Allyl thermally releasable groups such as allyl group and methallyl group; Silyl ether thermally releasable groups such as trimethylsilyl group, triethylsilyl group, and tert-butyldimethylsilyl group. Examples include releasing groups.

Among the above, the alkyl group having 1 to 7 carbon atoms may be linear or branched, such as 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; norbornyl group, adamantyl group, etc. polycyclic alicyclic saturated hydrocarbon groups; and the like. The alicyclic saturated hydrocarbon group may have a substituent on the ring portion. Examples of the substituent include a methyl group and an ethyl group.

Examples of the alkoxyalkyl group having 2 to 6 carbon atoms include a methoxymethyl group and an ethoxyethyl group.
In the substituted 2-tetrahydrofuranyl group and the substituted 2-tetrahydropyranyl group, examples of the substituent include an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, an acetoxy group, a benzyloxy group, etc. can be mentioned. Specific examples of the substituted or unsubstituted 2-tetrahydropyranyl group and the substituted or unsubstituted 2-tetrahydrofuranyl group include groups represented by the following formulas.

The heat-eliminating ^group represented by , or a substituted or unsubstituted 2-tetrahydrofuranyl group, more preferably a substituted or unsubstituted 2-tetrahydropyranyl group, and even more preferably an unsubstituted 2-tetrahydropyranyl group. preferable.

（式（ｘ－１）中、Ｘ^１は、水素原子又は熱脱離性基である。Ｒ^５は、炭素数１～５の鎖状又は分岐状のアルカンジイル基である。「＊」は結合手を表す。） From the viewpoint of reactivity, the group represented by "-OX ^{1 "} is preferably bonded to an aliphatic hydrocarbon structure, and more preferably bonded to a saturated chain hydrocarbon structure. Specifically, compound (C) preferably has a plurality of partial structures represented by the following formula (x-1) in one molecule.

(In formula (x-1), X ¹ is a hydrogen atom or a thermally releasable group. R ⁵ is a chain or branched alkanediyl group having 1 to 5 carbon atoms. "*" (Represents a bond.)

In formula (x-1), R ⁵ is preferably an alkanediyl group having 1 to 3 carbon atoms, particularly preferably an ethylene group, from the viewpoint of reactivity. Specific examples and preferred examples of X ¹ include the same groups as exemplified in the above explanation. "*" is preferably a bond bonded to a nitrogen atom.

The group represented by “-OX ¹ ” possessed by the compound (C) may be a monovalent group in which part of X ¹ in the compound (C) has a tetrahydropyran ring structure or a tetrahydrofuran ring structure, All X ¹ may be a monovalent group having a tetrahydropyran ring structure or a tetrahydrofuran ring structure. The compound (C) has " ^-OX It is preferable that all X ¹ of the groups represented by `` are monovalent groups having a tetrahydropyran ring structure or a tetrahydrofuran ring structure, and more preferably a monovalent group having a tetrahydropyran ring structure. .

The number of groups represented by “-OX ¹ ” possessed by the compound (C) is preferably 2 to 10, and 3 to 10 from the viewpoint of achieving a good balance between the mechanical strength and liquid crystal orientation of the liquid crystal alignment film. More preferably 8 pieces, and even more preferably 3 to 6 pieces.

（式（１）中、Ｘ^１は水素原子又は熱脱離性基である。Ｒ^１ａは水素原子又は炭素数１～４の１価の有機基である。Ｒ^１ｂ及びＲ^１ｃは、それぞれ独立して、水素原子又は炭素数１～８の１価の有機基である。「＊」は結合手を表す。） The compound (C) preferably has a β-hydroxyalkylamide structure in that it can react with the carboxyl group of the polymer (P) at a relatively low temperature to form a crosslinked structure. Specifically, compound (C) preferably has a partial structure represented by the following formula (1).

(In formula (1), X ¹ is a hydrogen atom or a thermally releasable group ^. R ^1a is a hydrogen atom or a monovalent organic group having 1 to 4 carbon atoms ^. It is a hydrogen atom or a monovalent organic group having 1 to 8 carbon atoms. "*" represents a bond.)

In the above formula (1), the monovalent organic group having 1 to 4 carbon atoms represented by R ^1a is preferably a linear or branched alkyl group having 1 to 4 carbon atoms, and a methyl group or an ethyl group is preferable. More preferred. From the viewpoint of increasing the reactivity of compound (C), R ^1a is preferably a hydrogen atom or a methyl group, and more preferably a hydrogen atom. The monovalent organic group having 1 to 8 carbon atoms represented by R ^1b and R ^1c preferably has a group represented by "-OX ¹ ". From the viewpoint of increasing the reactivity of compound (C), R ^1b and R ^1c are preferably hydrogen atoms. Specific examples and preferred examples of X ¹ include the same groups as exemplified in the above explanation.

A monovalent group may be bonded to the nitrogen atom in the above formula (1). Further, the nitrogen atom in the above formula (1) may form part of a ring together with the adjacent carbonyl group. When a monovalent group is bonded to the nitrogen atom in the above formula (1), examples of the monovalent group include a thermally releasable group, a hydroxyalkyl group, a protected hydroxyalkyl group, and the like. When the nitrogen atom in the above formula (1) forms part of a ring together with a carbonyl group, examples of the ring include an isocyanurate ring and an imidazolidinone ring.

（式（２）中、Ｘ^１は水素原子又は熱脱離性基である。ただし、式中の４個のＸ^１は同一又は異なり、４個のＸ^１のうち１個以上はテトラヒドロピラン環構造又はテトラヒドロフラン環構造を有する１価の基である。Ｒ^２は２価の有機基である。） Specifically, the compound (C) is preferably a compound represented by the following formula (2).

(In formula (2), X ¹ is a hydrogen atom or a thermally releasable group. However, the four X ^1s in the formula are the same or different, and one or more of the four X ^1s is a tetrahydropyran ring. ( ^R2 is a divalent organic group.)

In the above formula (2), the divalent organic group represented by R ² 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. A divalent group substituted with a containing group (provided that R ⁷ and R ⁸ are each independently a hydrogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms, or a thermally releasable group). ) etc.

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, and a divalent alicyclic group having 3 to 20 carbon atoms. Examples include a hydrocarbon group having the formula: a divalent aromatic hydrocarbon group having 6 to 20 carbon atoms, and the like. Among these, the divalent hydrocarbon group represented by R ² is preferably a chain hydrocarbon group or an alicyclic hydrocarbon group, such as an alkanediyl group having 1 to 12 carbon atoms, or an alkenediyl group having 2 to 12 carbon atoms. A group or a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms is more preferable. Among these, an alkanediyl group having 1 to 12 carbon atoms or an alkenediyl group having 2 to 12 carbon atoms is particularly preferable, an alkanediyl group having 1 to 6 carbon atoms or an alkenediyl group having 2 to 6 carbon atoms is more preferable, and an alkanediyl group having 1 to 6 carbon atoms is more preferable. More preferred are alkenediyl groups having 1 to 4 carbon atoms or alkenediyl groups having 2 to 4 carbon atoms. When R ² is a chain group (alkanediyl group, alkenediyl group, etc.), it may be linear or branched. From the viewpoint of increasing liquid crystal orientation 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 carboxy group, and a halogen atom.

When R ² is a divalent group (hereinafter also referred to as "divalent group R ⁸ ") in which any methylene group in a substituted or unsubstituted hydrocarbon group is replaced with a heteroatom-containing group, Specific examples include groups in which one or more methylene groups in the above-exemplified substituted or unsubstituted hydrocarbon groups are replaced with heteroatom-containing groups. The divalent group R ⁸ may be a group consisting of a chain structure, and may have a cyclic structure (aliphatic hydrocarbon ring, aromatic hydrocarbon ring, aliphatic heterocycle, aromatic heterocycle, etc.). It's okay. Examples of the aliphatic heterocycle include a piperidine ring, piperazine ring, etc. as a nitrogen-containing aliphatic heterocycle; an oxetane ring, a tetrahydrofuran ring, a dioxolane ring, etc. as an oxygen-containing aliphatic heterocycle; a tetrahydrothiophene ring as a sulfur-containing aliphatic heterocycle etc. can be mentioned respectively. In addition, examples of aromatic heterocycles include pyridine ring, pyrimidine ring, pyridazine ring, pyrazine ring, etc. as nitrogen-containing aromatic heterocycle; furan ring, etc. as oxygen-containing aromatic heterocycle; thiophene ring as sulfur-containing aromatic heterocycle. Rings, etc. can be mentioned respectively.

Among the above, R ² is a divalent chain hydrocarbon group, 2 The alicyclic hydrocarbon group or any methylene group in the hydrocarbon group is a heteroatom-containing group (preferably -O-, -S-, -NR ⁷ -, -CONR ⁷ -, -CO-, - It is preferably a divalent group substituted with COO-, -NR ⁷ -CO-NR ⁸ -, -NR ⁷ -CO-O- or -CONR ⁷ -NR ⁸ CO-), and a divalent chain More preferably, it is a divalent group in which any methylene group in the hydrocarbon group or chain hydrocarbon group is replaced with a heteroatom-containing group. In this case, the number of carbon atoms in R ² is preferably 1 to 20, more preferably 1 to 12, and still more preferably 1 to 6.

Compound (C) preferably has a group represented by "--NY ¹ --" (wherein Y ¹ is a thermally releasable group) in the molecule. It is preferable that the compound (C) has a group represented by "--NY ¹ --" since the reliability of the liquid crystal element can be improved. When compound (C) is a compound represented by the above formula (2), it is preferable that R ² in the above formula (2) has a group represented by "-NY ¹ -".

Examples of the thermally releasable group represented by Y ¹ include a carbamate type thermally releasable group, an amide type thermally releasable group, an imide type thermally releasable group, a sulfonamide type thermally releasable group, etc. Can be mentioned. Among these, carbamate-based thermally releasable groups are preferred because they have high thermally releasable properties. Specific examples include tert-butoxycarbonyl group, benzyloxycarbonyl group, 1,1-dimethyl-2-haloethyloxycarbonyl group, allyloxycarbonyl group, 2-(trimethylsilyl)ethoxycarbonyl group, 9-fluorenyl group. Examples include methyloxycarbonyl group and allyloxycarbonyl group. Among these, a tert-butoxycarbonyl group (Boc group) is particularly preferable because it has excellent thermal removability and can reduce the amount of the deprotected portion remaining in the film.

When compound (C) has a group represented by "-NY ¹ -", the number of groups represented by "-NY ¹ -" in one molecule of compound (C) is not particularly limited, and may be 1 or more. That's fine. The number of groups represented by "--NY ¹ --" that the compound (C) has is, for example, 1 to 4.

The group represented by "-NY ¹ -" has one or both bonding hands bonded to an aliphatic hydrocarbon structure from the viewpoint of the crosslinkability of the compound (C) and the reliability of the obtained liquid crystal alignment film. More preferably, both bonds are bonded to an aliphatic hydrocarbon structure. The aliphatic hydrocarbon structure may be saturated or unsaturated, and may be chain or cyclic. The aliphatic hydrocarbon structure adjacent to the group represented by "-NY ¹ -" is preferably a chain structure, more preferably a saturated chain structure (ie, an alkanediyl group).

When R ² in the above formula (2) has a group represented by "-NY ¹ -", -NH- (basic functional group) is generated by detachment of Y ¹ by heating during film formation. The number of groups represented by "-NY ¹ -" in R ² is set to 1 or 2 from the viewpoint of trapping acidic impurities in the liquid crystal cell with the generated -NH- and improving the reliability of the liquid crystal element. preferable.

（式（ｘ２－１）～式（ｘ２－５）中、「＊」は結合手を表す。） Specific examples and preferred examples of X ¹ include the same groups as exemplified in the above explanation. Preferred specific examples when X ¹ is a monovalent group having a tetrahydropyran ring structure or a tetrahydrofuran ring structure include a group represented by any of the following formulas (x2-1) to (x2-5). Can be mentioned. Among these, X ¹ is preferably a group represented by either the following formula (x2-1) or formula (x2-2).

(In formulas (x2-1) to (x2-5), "*" represents a bond.)

（式（ｃ－１）～式（ｃ－３１）中、Ｘ^２は、水素原子又は上記式（ｘ２－１）～式（ｘ２－５）のいずれかで表される基である。ただし、式中の複数のＸ^２は同一又は異なり、複数のＸ^２のうち１個以上は、上記式（ｘ２－１）～式（ｘ２－５）のいずれかで表される基である。式（ｃ－２３）中、ｎは１～５の整数である。） Specific examples of compound (C) include compounds represented by each of the following formulas (c-1) to (c-31).

(In formulas (c-1) to (c-31), X ² is a hydrogen atom or a group represented by any of the above formulas (x2-1) to (x2-5). However, A plurality of X ² in the formula is the same or different, and one or more of the plurality of X ² is a group represented by any one of the above formulas (x2-1) to (x2-5).Formula ( c-23), where n is an integer from 1 to 5.)

Among the above, compound (C) has the formulas (c-1) to (c-4), formulas (c-13) to (c-15), and formulas (c-18) to (c- 21), formula (c-24), formula (c-28), and formula (c-29) are preferred, and the compounds represented by the above formulas (c-1) to (c-4), formula ( Compounds represented by each of c-13) to formula (c-15) and formula (c-18) to formula (c-21) are more preferred, and the above formulas (c-1) and (c-2) , Formula (c-13), Formula (c-14), Formula (c-18), and Formula (c-20) are more preferred.

In the liquid crystal alignment agent of the present disclosure, the content ratio of the compound (C) is determined based on the polymer component contained in the liquid crystal alignment agent, from the viewpoint of obtaining a liquid crystal alignment film with high mechanical strength and from the perspective of obtaining a highly reliable liquid crystal element. It 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, based on 100 parts by mass of the total amount. In addition, the content ratio of the compound (C) should be 50 parts by mass or less with respect to 100 parts by mass of the total amount of polymer components contained in the liquid crystal aligning agent, from the viewpoint of suppressing a decrease in the toughness of the liquid crystal aligning film. is preferred, more preferably 40 parts by mass or less, and still more preferably 30 parts by mass or less.

[Synthesis of compound (C)]
Compound (C) can be synthesized by appropriately combining conventional methods of organic chemistry. An example of a method for synthesizing compound (C) is to react a carboxylic acid or a derivative thereof with a hydroxyalkylamine to synthesize an intermediate in which all X ¹ in compound (C) are hydrogen atoms; A method of protecting the hydroxyl group of a hydroxyalkylamine with a thermally releasable group, or synthesizing an intermediate by protecting the hydroxyl group of a hydroxyalkylamine with a thermally releasable group, and reacting the intermediate with a carboxylic acid or its derivative. There are several methods. These methods are simple and can provide compound (C) in high yield.

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

<Other ingredients>
In addition to the polymer (P) and the compound (C), the liquid crystal aligning agent contains components different from the polymer (P) and the compound (C) (hereinafter also referred to as "other components") as necessary. You may do so.

-Other polymers The liquid crystal aligning agent of the present disclosure may further contain a polymer (hereinafter also referred to as "other polymer") that does not have a carboxy group. The main skeleton of the other polymers is not particularly limited. Examples of other polymers include polyorganosiloxanes, polyesters, polyenamines, polyureas, polyamides, addition polymers (for example, (meth)acrylic polymers, styrene polymers, maleimide polymers, and styrene-maleimide copolymers). polymer), etc. Among these, the other polymer is preferably at least one selected from the group consisting of polyorganosiloxane and addition polymer.

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

-Solvent The liquid crystal aligning agent of the present disclosure is a liquid composition in which the polymer (P), the compound (C), and other components used as necessary are preferably dispersed or dissolved in an appropriate solvent. It is prepared as

As the solvent, organic solvents are preferably used. 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 acetoacetate, ethyl propionate, methylmethoxypropionone ethyl ethoxypropionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene Glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol 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, Examples include 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 the solvent, one type can be used alone or two or more types can be used in combination.

In addition to the above, other components to be added to the liquid crystal aligning agent include adhesion aids, antioxidants, metal chelate compounds, curing accelerators, surfactants, fillers, dispersants, photosensitizers, etc. Can be mentioned. The blending ratio of other components can be appropriately selected depending on each compound within a range that does not impair the effects of the present disclosure.

The solid concentration in the liquid crystal aligning agent (the ratio of the total mass of components other than the solvent of the liquid crystal aligning agent to the total mass of the liquid crystal aligning agent) is appropriately selected in consideration of viscosity, volatility, etc. The solid content concentration of the liquid crystal aligning agent is preferably in the range of 1 to 10% by mass. It is suitable that the solid content concentration is 1% by mass or more because a sufficient thickness of the coating film can be ensured and a liquid crystal alignment film exhibiting better liquid crystal alignment properties can be obtained. On the other hand, when the solid content concentration is 10% by mass or less, the coating film can be made to have an appropriate thickness, a liquid crystal alignment film that exhibits good liquid crystal alignment properties is easily obtained, and the viscosity of the liquid crystal alignment agent is moderate. This tends to improve coating properties.

<<Liquid crystal alignment film and liquid crystal element>>
The liquid crystal aligning film of the present disclosure is manufactured using the liquid crystal aligning agent prepared as described above. Moreover, the liquid crystal element of this indication comprises the liquid crystal alignment film formed using the liquid crystal alignment agent demonstrated above. The driving method of the liquid crystal in the liquid crystal element is not particularly limited, and includes, for example, TN type, STN type, VA type (including VA-MVA type, VA-PVA type, etc.), IPS type, FFS type, and OCB (Optically Compensated Bend). It can be applied to various modes such as type, PSA (Polymer Sustained Alignment) type, and ECB (Electrically Controlled Birefringence) type. A liquid crystal element can be manufactured, for example, by a method including steps 1 to 3 below. In step 1, the substrate used differs depending on the desired operation mode. Steps 2 and 3 are common to each operation mode.

<Step 1: Formation of coating film>
First, a liquid crystal aligning agent is applied onto a substrate, and a coating film is formed on the substrate, preferably by heating the applied surface. As the substrate, for example, a transparent substrate made of glass such as float glass or soda glass; or plastic such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, polycarbonate, or poly(alicyclic olefin) can be used. The transparent conductive film provided on one side of the substrate includes a NESA film (registered trademark of PPG, USA) made of tin oxide (SnO ₂ ) and an ITO film made of indium oxide-tin oxide (In ₂ O ₃ -SnO ₂ ). etc. can be used. When manufacturing a TN type, STN type, or VA type liquid crystal element, two substrates each having a patterned transparent conductive film are used. On the other hand, when manufacturing an IPS type or FFS type liquid crystal element, a substrate provided with comb-shaped patterned electrodes and a counter substrate provided with no electrodes are used.

The method of applying the liquid crystal alignment agent to the substrate is not particularly limited. The liquid crystal alignment agent can be applied to the substrate using, for example, a spin coat method, a printing method (e.g. offset printing method, flexo printing method, etc.), an inkjet method, a slit coat method, a bar coater method, an extrusion die method, or a direct gravure method. This can be carried out by a coater method, a chamber doctor coater method, an offset gravure coater method, an impregnation coater method, an MB coater method, or the like.

After applying the liquid crystal aligning agent, preheating (prebaking) is preferably performed for the purpose of preventing the applied liquid crystal aligning agent from dripping. The prebake temperature is preferably 30 to 200°C, and the prebake time is preferably 0.25 to 10 minutes. Thereafter, a calcination (post-bake) step is performed for the purpose of completely removing the solvent and, if necessary, thermally imidizing 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. Post-bake time is preferably 5 to 200 minutes. The thickness of the formed film is preferably 0.001 to 1 μm.

<Step 2: Orientation treatment>
When manufacturing a TN-type, STN-type, IPS-type, or FFS-type liquid crystal element, the coating film formed in step 1 is subjected to a treatment (orientation treatment) that imparts liquid crystal alignment ability. Thereby, the ability to orient liquid crystal molecules is imparted to the coating film, and it becomes 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, nylon, etc., or a photoalignment treatment in which the coating film is irradiated with light to impart liquid crystal alignment ability. When manufacturing a vertically aligned liquid crystal element, the coating film formed in step 1 above may be used as it is as a liquid crystal alignment film, or the coating film may be subjected to an alignment treatment in order to further enhance the liquid crystal alignment ability. It's okay. A liquid crystal alignment film suitable for a vertical alignment type liquid crystal element can also be preferably used for a PSA type liquid crystal element.

Light irradiation for photo-alignment can be performed by irradiating the coating film after the post-bake process, by irradiating the coating film after the pre-bake process but before the post-bake process, or by irradiating the coating film after the pre-bake process but before the post-bake process. At least one of these methods can be carried out by irradiating the coating film while the coating film is being heated. As the radiation irradiated to the coating film, for example, ultraviolet rays and visible light including light with a wavelength of 150 to 800 nm can be used. Preferably, it is ultraviolet light containing light with a wavelength of 200 to 400 nm. If the radiation is polarized, it may be linearly polarized or partially polarized. When the radiation used is linearly polarized or partially polarized, the irradiation may be performed from a direction perpendicular to the substrate surface, from an oblique direction, or a combination thereof. In the case of non-polarized radiation, the irradiation direction is oblique.

Examples of the light source used include a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, and an excimer laser. The radiation dose is preferably 200 to 30,000 J/m ² , more preferably 500 to 10,000 J/m ² . After light irradiation for imparting alignment ability, the substrate surface is treated with water, an organic solvent (e.g., methanol, isopropyl alcohol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, etc.), or a mixture thereof. A cleaning process or a process of heating the substrate may also be performed.

<Step 3: Construction of liquid crystal cell>
A liquid crystal cell is manufactured by preparing two substrates on which liquid crystal alignment films are formed as described above, and disposing a liquid crystal between the two substrates that are arranged facing each other. To manufacture a liquid crystal cell, for example, two substrates are placed facing each other with a gap in between so that the liquid crystal alignment films face each other, and the peripheral parts of the two substrates are bonded together using a sealant, and the surface of the substrate and the sealant are bonded together. Examples include a method in which liquid crystal is injected into a cell gap surrounded by , and the injection hole is sealed, a method using an ODF method, and the like. As the sealant, for example, an epoxy resin containing a hardening 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.

In the PSA mode, a polymerizable compound (for example, a polyfunctional (meth)acrylate compound, etc.) is filled into the cell gap together with liquid crystal, and after the liquid crystal cell is constructed, a voltage is applied between the conductive films of a pair of substrates. In this step, the liquid crystal cell is irradiated with light. When producing a PSA type liquid crystal element, the proportion of the polymerizable compound used is, for example, 0.01 to 3 parts by weight, preferably 0.05 to 1 part by weight, based on a total of 100 parts by weight of the liquid crystal.

When manufacturing a liquid crystal display device, a polarizing plate is then bonded to the outer surface of the liquid crystal cell. Examples of the polarizing plate include a polarizing plate in which a polarizing film called "H film" in which polyvinyl alcohol is stretched and oriented and absorbs iodine is sandwiched between cellulose acetate protective films, or a polarizing plate made of the H film itself.

The liquid crystal element of the present disclosure can be effectively applied to various uses. Specifically, for example, 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, LCD televisions, information displays, etc. , a light control device, a retardation film, etc.

≪Thermosetting composition≫
The thermosetting composition of the present disclosure comprises a polymer (P) having a carboxy group and a group represented by "-OX ¹ " (wherein, X ¹ is a hydrogen atom or a thermally releasable group). The compound (C) has a plurality of groups in the molecule, and one or more of the groups represented by "-OX ¹ " is a monovalent group in which X ¹ is a monovalent group having a tetrahydropyran ring structure or a tetrahydrofuran ring structure. , contains.

The polymer (P) and compound (C) contained in the thermosetting composition of the present disclosure, as well as other optionally blended components, are as described above.

The polymer composition containing the polymer (P) and the compound (C) forms a crosslinked structure by heat and exhibits thermosetting properties. Therefore, according to the thermosetting composition of the present disclosure, when used, for example, as a pressure-sensitive adhesive, adhesive, dispersant, coating agent, etc., a cured product with excellent thermosetting properties can be obtained. Further, according to the thermosetting composition of the present disclosure, it is also possible to obtain a cured product with excellent heat resistance, adhesiveness, and flexibility.

Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples.

<Compound structure and abbreviation>
The structures and abbreviations of the main compounds used in the examples below are as follows.
[Tetracarboxylic dianhydride]
Compound (TA-1) to Compound (TA-5); Compounds represented by the following formulas (TA-1) to (TA-5), respectively

[Diamine]
Compound (DA-1) to Compound (DA-14); Compounds represented by the following formulas (DA-1) to (DA-14), respectively

[Crosslinking agent]
Compound (AD-1) to Compound (AD-12); Compounds represented by the following formulas (AD-1) to (AD-12), respectively

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

<Synthesis of compounds>
[Synthesis example 1]
In a three-necked flask equipped with a nitrogen introduction tube, N,N,N',N'-tetrakis(2-hydroxyethyl)adipamide (10 mmol), 3,4-dihydropyran (60 mmol), and pyridinium p-toluenesulfonate. (2 mmol) and methylene chloride (50 mL) were added thereto, and the mixture was heated and stirred at 30° C. for 12 hours under nitrogen. After the reaction was completed, water was added for separation and washing, and the organic phase was vacuum dried to obtain a colorless viscous liquid compound represented by the following formula (AD-1) in a yield of 99%. FIG. 1 shows the measurement results of ¹ H-NMR spectrum (DMSO-d ₆ , 400 MHz) of compound (AD-1).

[Synthesis example 2]
Compound (AD-2) was synthesized in the same manner as Synthesis Example 1 according to the reaction scheme below. FIG. 2 shows the measurement results of ¹ H-NMR spectrum (DMSO-d ₆ , 400 MHz) of compound (AD-2).

[Synthesis example 3]
Diethanolamine (50 mmol) and acetonitrile (50 mL) were placed in a three-necked flask equipped with a nitrogen inlet tube and cooled to 0°C, then methanesulfonic acid (55 mmol) was added, and 3,4-dihydropyran (125 mmol) was added. The mixture was added dropwise little by little and stirred at room temperature under nitrogen for 12 hours. After the reaction was completed, it was cooled to 0°C, quenched by adding a potassium hydroxide aqueous solution little by little, ethyl acetate (50 mL) was added, water was added for separation washing, and the organic phase was vacuum-dried to give a brown color. A liquid compound O,O'-bis(2-tetrahydropyranyl)-diethanolamine represented by the following formula (AD-7-1) was obtained in a yield of 46%. FIG. 3 shows the measurement results of ¹ H-NMR spectrum (CDCl ₃ , 400 MHz) of compound (AD-7-1).

[Synthesis example 4]
Compound (AD-7) was synthesized according to the reaction scheme below.

[Synthesis example 5]
Compound (AD-8) was synthesized according to the reaction scheme below. Note that 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. FIG. 4 shows the measurement results of ¹ H-NMR spectrum (CDCl ₃ , 400 MHz) of compound (AD-8).

[Synthesis example 6]
Compound (AD-11) was synthesized according to the reaction scheme below.

[Synthesis example 7]
Compound (AD-12) was synthesized according to the reaction scheme below.

[Reference synthesis example 1]
Compound (AD-3) was synthesized according to the description in Korean Patent Publication No. 2019-125717.
[Reference synthesis example 2]
Compound (AD-4) was synthesized according to the description in Korean Patent Publication 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 below.

<Compound evaluation>
The following evaluations were performed for each crosslinking agent (compounds (AD-1) to (AD-12)). The evaluation results are shown in Table 1 below.

[Evaluation of storage stability]
A crosslinking agent and p-nitrobenzoic acid were each dissolved in water at a concentration of 1% by mass based on deuterated dimethyl sulfoxide, and ¹ H-NMR was measured at room temperature. Subsequently, after storing this solution at room temperature for two weeks, ¹ H-NMR was measured again, and changes in the ¹ H-NMR spectrum (400 MHz) before and after storage at room temperature were observed. The evaluation was rated as "good" if there was no change, and "poor" if there was any change.

[Evaluation of thermal stability]
Thermogravimetric analysis was performed on each crosslinking agent under nitrogen at a heating rate of 10°C per minute from 30°C to 500°C. The evaluation is performed by calculating the 5% weight loss temperature Td5 (however, if the crosslinking agent has a protective group, the temperature at which the weight decreases by 5% with respect to the weight excluding the protective group), and Td5 is 230 ° C. or higher. The case was judged as "good", and the case where Td5 was less than 230°C was judged as "poor".

[Evaluation of hydrophobicity]
For each crosslinker, the solubility parameter δ (cal ^0.5 cm ^−1.5 ) was determined using the computer software HSPiP (version 5.2.07). The evaluation was made as "excellent" when δ was less than 10, "good" when δ was 10 or more and less than 12, and "poor" when δ was 12 or more.

As shown in Table 1, the compound (AD-1) has a plurality of groups represented by "-OX ¹ " in one molecule, and one or more X ¹ is a tetrahydropyran structure or a tetrahydrofuran structure, ( AD-2), (AD-7), (AD-8), (AD-11), and (AD-12) were evaluated as good in terms of storage stability, thermal stability, and hydrophobicity.

<Synthesis and evaluation of polymer>
Polymers were synthesized according to Synthesis Examples 8 to 17 below. In addition, in the following examples, the weight average molecular weight (M _w ) and number average molecular weight (M _n ) of the polymer, the imidization rate of polyimide in the polymer solution, the solution viscosity of the polymer solution, and the epoxy equivalent of the polymer was measured by the following method.

[Weight average molecular weight _Mw and number average molecular weight _Mn ]
M _w and M _n are polystyrene equivalent values measured by GPC under the following conditions.
Column: manufactured by Tosoh Corporation, TSKgelGRCXLII
Solvent: Tetrahydrofuran Temperature: 40℃
Pressure: 68kgf/ ^cm2

[Imidization rate of polyimide]
A polyimide solution was poured into pure water, and the resulting precipitate was thoroughly dried under reduced pressure at room temperature, then dissolved in deuterated dimethyl sulfoxide, and ¹ H-NMR was measured at room temperature using tetramethylsilane as a reference substance. From the obtained ¹ H-NMR spectrum (400 MHz), the imidization rate [%] was determined using the following formula (1).
Imidization rate [%] = (1 - (A ₁ / (A ₂ × α))) × 100 ... (1)
(In formula (1), A ₁ is the peak area derived from the proton of the amide group that appears around the chemical shift of 10 ppm, A ₂ is the peak area derived from the proton of the aromatic group that appears around the chemical shift of 6 to 9 ppm, α is the ratio of the number of aromatic group protons to one amide group proton in the polymer precursor (polyamic acid).)

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

[Synthesis example 8]
Diamine (50 mole parts of diamine (DA-1), 30 mole parts of diamine (DA-2), and 20 mole parts of diamine (DA-3) based on 100 mole parts of the total amount of diamines used) was dissolved in NMP. Then, 0.95 molar equivalent of tetracarboxylic dianhydride (TA-2) was added to the total amount of diamine, and the reaction was carried out at room temperature for 6 hours to obtain a solution of polyamic acid. To the obtained solution, 1-methylpiperidine and acetic anhydride in an amount of 0.40 molar equivalent based on the carboxy group of the polyamic acid were added as a dehydrating agent, 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%.

[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 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 equivalent. The imidization rate of polyimide (PI-3) was 100%.

[Synthesis example 11]
Diamine (30 mole parts of diamine (DA-3), 40 mole parts of diamine (DA-5), 20 mole parts of diamine (DA-6), and 20 mole parts of diamine (DA-6) based on 100 mole parts of the total amount of diamines used. 7) Dissolve 10 mole parts of tetracarboxylic dianhydride in NMP, and dissolve 0.95 mole equivalent of tetracarboxylic dianhydride based on the total amount of diamine (based on 100 mole parts of the total amount of tetracarboxylic dianhydride used). 70 mol parts of dianhydride (TA-1) and 30 mol parts of acid dianhydride (TA-4) were added, and the reaction was carried out at room temperature for 6 hours to form a 15% by mass solution of polyamic acid (PA-1). Obtained.

[Synthesis Examples 12 to 15]
Polyamic acids (PA-2) to (PA-5) were prepared in the same manner as in Synthesis Example 11, except that the types and molar ratios of the tetracarboxylic dianhydride and diamine were changed as shown in Table 2 below. A solution containing % by mass was obtained.

For acid dianhydrides, the numerical values in Table 2 indicate the proportions (mol%) of each compound relative to the total amount (100 mol%) of tetracarboxylic dianhydrides used in the synthesis, and for diamines, they indicate the proportion of each compound used in the synthesis (100 mol%). The usage ratio (mol%) of each compound with respect to the total amount (100mol%) of diamine used in is shown.

[Synthesis example 16]
100.0 g of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane (a compound represented by the following formula (S-1)) was placed in a reaction vessel equipped with a stirrer, a thermometer, a dropping funnel, and a reflux condenser. , 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 while stirring under reflux. After the reaction, the organic layer is taken out and washed with a 0.2% by mass ammonium nitrate aqueous solution until the water after washing becomes neutral, and then the solvent and water are distilled off under reduced pressure to remove the epoxy group. Polyorganosiloxane (ESSQ-1) was obtained as a viscous transparent liquid. When ¹ H-NMR analysis was performed on polyorganosiloxane (ESSQ-1), a peak based on epoxy groups was observed near chemical shift (δ) = 3.2 ppm, indicating that side reactions of epoxy groups occurred during the reaction. It has been confirmed that this is not the case. The weight average molecular weight _Mw of the obtained polyorganosiloxane (ESSQ-1) 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 a compound represented by the following formula (S-2) and the following formula as a modifying component (carboxylic acid). The compound represented by (S-3) was added in an amount equivalent to 20 mol% and 10 mol%, respectively, based on the total amount of epoxy groups possessed by polyorganosiloxane (ESSQ-1), and UCAT 18X (product name) was added as a catalyst. 0.10 g of San-Apro Co., Ltd.) was added, and the reaction was carried out at 100° C. for 48 hours with stirring. After completion of the reaction, the solution obtained by adding ethyl acetate to the reaction mixture was washed with water three times, the organic layer was dried using magnesium sulfate, and the solvent was distilled off to obtain a polyorganosiloxane containing an orienting group. (PSQ-1) was obtained. The weight average molecular weight _Mw of the obtained polymer was 8,000.

[Synthesis example 17]
Under nitrogen, in a 100 mL two-necked flask, 6.38 g of a compound represented by the following formula (M-1) and 4-(glycidyloxymethyl)styrene (a compound represented by the following formula (M-2)) were added as polymerization monomers. ), 0.86 g of methacrylic acid, 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. was added and polymerized 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 desired polymer (PMI-1). The weight average molecular weight M _w of the obtained polymer was 30,000, and the molecular weight distribution M _w /M _n was 2.

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

(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 on which no electrodes are provided, respectively. The liquid crystal aligning agent (AL-1) prepared in (1) above was applied using a spin coater, heated for 1 minute on a hot plate at 80°C, and then placed in an oven at 230°C with the interior replaced with nitrogen. Heating was performed for 30 minutes to form a coating film with an average thickness of 100 nm. The surface of this coating film was subjected to photo-alignment treatment by irradiating 200 mJ/cm ² of ultraviolet light containing a linearly polarized bright line of 254 nm from the normal direction of the substrate using a Hg-Xe lamp. The coating film subjected to this photo-alignment treatment was heat-treated by heating for 30 minutes in an oven at 230° C. in which the inside of the oven was replaced with nitrogen, to form a liquid crystal alignment film.

(3) Manufacture of FFS type liquid crystal display element Out of the pair of substrates having the liquid crystal alignment film formed in (2) above, a liquid crystal injection port is left on the outer periphery of the surface having the liquid crystal alignment film, and the diameter is 3.5 μm. After applying an epoxy resin adhesive containing aluminum oxide spheres with a dispenser, the surfaces of the pair of substrates with the liquid crystal alignment film were placed opposite each other, and the substrates were pressed together so that the alignment direction of each substrate was antiparallel, and heated at 150°C for 1 hour. The adhesive was cured by heat. Next, a negative nematic liquid crystal (manufactured by Merck, MJ20195NCMP) was filled into the gap between the substrates through a liquid crystal injection port, and then the liquid crystal injection port was sealed with an epoxy adhesive. Furthermore, in order to remove the fluid orientation during injection of the liquid crystal, it was heated at 120° C. and then slowly cooled to room temperature. Next, an FFS type liquid crystal display element is manufactured by pasting polarizing plates on both outer sides of the substrate so that their polarization directions are perpendicular to each other and form an angle of 45° with the alignment treatment direction of the liquid crystal alignment film. did.

(4) Evaluation of liquid crystal orientation (orientation uniformity) Regarding the liquid crystal display element manufactured in (3) above, the presence or absence of abnormal domains in the change in brightness when a voltage of 5V is turned on and off (applied/removed) is examined using a microscope. Observation was made at a magnification of 50 times. The evaluation was evaluated as "good" when no abnormal domain was observed, and "poor" when an abnormal domain was observed. As a result, this example was evaluated as "good".

(5) Evaluation of liquid crystal orientation (alignment regulating ability) The liquid crystal display element manufactured in (3) above was backlit at an AC voltage of 11 V using a birefringence meter (AXOSTEP high-precision Muller matrix imaging polarimeter manufactured by AXOMETRICS). Changes in the liquid crystal orientation angle were measured before and after driving for 68 hours under irradiation. In the evaluation, a change in liquid crystal orientation angle of less than 0.1 degree was evaluated as "excellent," a change in liquid crystal orientation angle of 0.1 degree or more and less than 0.3 degree was evaluated as "good," and a change in liquid crystal orientation angle of 0.3 degree or more was evaluated as "poor." It can be said that the smaller the change in the liquid crystal azimuth angle, the less likely AC afterimage will occur even when the liquid crystal display element is driven for a long time, and the better the liquid crystal orientation will be. As a result, this example was evaluated as "excellent".

(6) Evaluation of mechanical properties (keystroke test resistance) The keystroke test resistance of the liquid crystal display element manufactured in (3) above was evaluated using a keystroke/sliding tester manufactured by NTS Co., Ltd. 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 (that is, the number of bright spots before the key was pressed) was counted. Next, the liquid crystal cell was fixed on a fixed plate, and a keying indenter having a Shore hardness of 50 was repeatedly dropped from a height of 6.0 mm to repeatedly apply a load to the liquid crystal cell. When applying the load, the load was 250 gf, the number of repetitions was 100,000 times, and the speed was 2 Hz. After the key was pressed, the liquid crystal cell was observed again, and the number of bright spots (that is, the number of bright spots after the key was pressed) was counted. The evaluation was evaluated as "good" when the difference in the number of bright spots before and after keystroke was less than 50, and as "bad" when it was 50 or more. If the difference in the number of bright spots is less than 50, it can be said that the mechanical strength of the membrane against keystrokes is good. As a result, this example was evaluated as "good".

(7) Evaluation of mechanical properties (wear resistance) The liquid crystal aligning agent (AL-1) prepared in (1) above was applied onto a glass substrate using a spin coater, and heated on a hot plate at 80°C for 1 minute. After heating, heating was performed for 30 minutes in a 230° C. oven with nitrogen purging inside the chamber to form a coating film with an average thickness of 100 nm, and the haze value of the coating film was measured using a hazemeter. Next, this coating film was subjected to rubbing treatment five times using a rubbing machine having a roll wrapped with cotton cloth at a roll rotation speed of 1000 rpm, a stage movement speed of 3 cm/sec, and a nap length of 0.3 mm. Thereafter, the haze value of the liquid crystal alignment film was measured using a haze meter, and the difference (haze change value) from the haze value before the rubbing treatment was calculated. When the haze value of the film before the rubbing process is Hz1 (%) and the haze value of the film after the rubbing process is Hz2 (%), the haze change value is expressed by the following formula (z-1).
Haze change value (%) = Hz2-Hz1 ... (z-1)
"Excellent" if the haze change value in the liquid crystal alignment film was less than 0.2, "Good" if it was 0.2 or more and less than 0.5, and "Poor" if it was 0.5 or more. And so. If the haze change value is less than 0.5, it can be said that the rubbing resistance is high and the mechanical properties of the film against surface abrasion are good. As a result, this example was evaluated as "good".

(8) Reliability evaluation A liquid crystal alignment film was formed in the same manner as in (2) above, except that the substrate on which the liquid crystal alignment agent was applied was changed to a glass substrate with ITO electrodes, and the same operations as in (3) above were performed. An ECB type liquid crystal display element was manufactured by performing the following steps. This liquid crystal display element was irradiated with light for 168 hours on a backlight using a CCFL as a light source. After applying a voltage of 1 V to the liquid crystal display element after light irradiation at 70° C. for an application time of 60 microseconds and a span of 1670 milliseconds, the voltage retention rate was measured 1670 milliseconds after the application was removed. Reliability was evaluated when the voltage holding rate was 70% or more, "good" when it was 60% or more, and "poor" when it was less than 60%. As a result, this example was evaluated as "good". As the voltage holding ratio measuring device, a model name "VHR-1" manufactured by Toyo Technica Co., Ltd. was used.

[Examples 2 to 4, Comparative Examples 1 to 7]
In the above Example 1, a liquid crystal aligning agent was prepared in the same manner as in Example 1 except that the polymer and crosslinking agent contained in the liquid crystal aligning agent were changed as shown in Table 3 below, and the liquid crystal aligning agent was aligned by a photo alignment method. Along with forming the film, an FFS type liquid crystal display element and an ECB type liquid crystal display element were manufactured and various evaluations were performed. The evaluation results are shown in Table 3 below.

[Example 5]
Example 1 is the same as Example 1 above, except that the polymer and crosslinking agent contained in the liquid crystal aligning agent were changed as shown in Table 3 below, and the exposure amount of linearly polarized ultraviolet rays was changed to 500 mJ/ ^cm2 . Similarly, a liquid crystal alignment agent was prepared and a liquid crystal alignment film was formed by a photoalignment method, and an FFS type liquid crystal display element and an ECB type liquid crystal display element were manufactured and various evaluations were performed. The evaluation results are shown in Table 3 below.

[Example 6, Comparative Example 8, Comparative Example 9]
In the above Example 5, a liquid crystal aligning agent was prepared in the same manner as in Example 5 except that the polymer and crosslinking agent contained in the liquid crystal aligning agent were changed as shown in Table 3 below, and the liquid crystal aligning agent was aligned by a photo alignment method. Along with forming the film, an FFS type liquid crystal display element and an ECB type liquid crystal display element were manufactured and various evaluations were performed. The evaluation results are shown in Table 3 below.

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

(2) Formation of liquid crystal alignment film by rubbing method A glass substrate on which a flat plate electrode, an insulating layer, and a comb-shaped electrode are laminated in this order on one side, and a counter glass substrate on which no electrodes are provided are formed on each side. The liquid crystal aligning agent (AL-16) prepared in (1) above was applied using a spin coater, heated for 1 minute on a hot plate at 80 °C, and then heated in an oven at 230 °C with the interior replaced with nitrogen. Heating was performed for 30 minutes to form a coating film with an average thickness of 100 nm. The surface of this coating film was subjected to rubbing orientation treatment twice using a rubbing machine with a roll wrapped with nylon cloth at a roll rotation speed of 1000 rpm, a stage movement speed of 30 mm/sec, and a nap length of 0.3 mm. went. The coating film subjected to this rubbing alignment treatment was ultrasonically cleaned in ultrapure water for 1 minute, and then dried in an oven at 100° C. for 10 minutes to form a liquid crystal alignment film.

(3) Manufacture of FFS type liquid crystal display element An FFS type liquid crystal display element was manufactured in the same manner as in Example 1 using the pair of substrates having the liquid crystal alignment film formed in (2) above.
(4) Evaluation of liquid crystal alignment (alignment uniformity) The liquid crystal alignment (alignment uniformity) of the FFS type liquid crystal display element manufactured in (3) above was evaluated in the same manner as in Example 1. As a result, this example was evaluated as "good".
(5) Evaluation of liquid crystal alignment (alignment regulating force) Regarding the FFS type liquid crystal display element manufactured in (3) above, liquid crystal alignment (alignment regulating force) was evaluated in the same manner as in Example 1. As a result, this example was evaluated as "good".

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

[Example 8, Comparative Examples 10-11]
In the above Example 7, a liquid crystal aligning agent was prepared in the same manner as in Example 7 except that the polymer and crosslinking agent to be contained in the liquid crystal aligning agent were changed as shown in Table 3 below, and a liquid crystal aligning agent was formed by a rubbing method. At the same time, 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.

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 the total of 100 parts by mass of the polymer components used for preparing the liquid crystal aligning agent. In Examples 1 to 8 and Comparative Examples 2 to 11, the blending ratio of the crosslinking agent was equimolar to 100 parts by mass of the polymer components in total.

[Example 9: PSA type liquid crystal display element]
(1) Preparation of liquid crystal alignment agent Polymer components (solid content equivalent: 95 parts by mass of polymer (PA-4), 5 parts by mass of polymer (PSQ-1)) and 11.3 parts of crosslinking agent (AD-7) By diluting parts by weight with NMP and BC, a solution having a solid content concentration of 4.0% by weight and a solvent composition ratio of NMP:BC=50:50 (mass ratio) was obtained. A liquid crystal aligning agent (AL-20) was prepared by filtering this solution through a filter with a pore size of 0.2 μm.

(2) Preparation of liquid crystal composition To 10 g of nematic liquid crystal (manufactured by Merck, MLC-6608), 5% by mass of a liquid crystal compound represented by the following formula (L-1) and the following formula (L-2) were added. A liquid crystal composition (LC-1) was obtained by adding and mixing 0.3% by mass of a photopolymerizable compound represented by:

(3) Formation of liquid crystal alignment film The liquid crystal alignment agent (AL-14) prepared in (1) above is applied onto each electrode surface of two glass substrates having ITO electrodes patterned into slits using a spin coater. After heating on a hot plate at 80° C. for 1 minute, heating was performed for 30 minutes in an oven at 230° C. in which the interior was replaced with nitrogen to form a coating film with an average thickness of 100 nm. This coating film was subjected to ultrasonic cleaning in ultrapure water for 1 minute, and then dried in an oven at 100°C for 10 minutes to form a liquid crystal alignment film. Note that the electrode pattern used was the same type of electrode pattern in the PSA mode.

(4) Manufacture of PSA type liquid crystal display element A liquid crystal injection port is left on the outer periphery of the surface of one of the pair of substrates on which the liquid crystal alignment film is formed in (3) above, and a diameter of 3.5 μm is formed. After applying the epoxy resin adhesive containing aluminum oxide balls with a dispenser, the surfaces of the pair of substrates having the liquid crystal alignment film were stacked and pressed together so as to face each other, and the adhesive was thermally cured at 150° C. for 1 hour. Next, after filling the liquid crystal composition (LC-1) prepared in (2) above into the gap between the substrates through the liquid crystal injection port, the liquid crystal cell is sealed by sealing the liquid crystal injection port with an epoxy adhesive. Manufactured.
For the obtained liquid crystal cell, AC 10 V with a frequency of 60 Hz was applied between the electrodes, and while the liquid crystal was being driven, ultraviolet rays of 10,000 mJ/cm ² were applied using an ultraviolet irradiation device using a metal halide lamp as a light source. It was irradiated at the same dose. Note that this irradiation amount is a value measured using a light meter that measures at a wavelength of 365 nm. Next, a PSA type liquid crystal display element is manufactured by pasting polarizing plates on both outer sides of the substrate so that their polarization directions are perpendicular to each other and form an angle of 45° with the alignment treatment direction of the liquid crystal alignment film. did.

(5) Evaluation of liquid crystal alignment (alignment uniformity) The liquid crystal alignment (alignment uniformity) 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 was evaluated as "good".

(6) Evaluation of mechanical properties (keystroke test resistance) The mechanical properties (keystroke test resistance) of the PSA type liquid crystal display element manufactured in (4) above were evaluated in the same manner as in Example 1. As a result, this example was evaluated as "good".

(7) Reliability evaluation 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 was evaluated as "excellent".

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

(2) Formation of liquid crystal alignment film by photoalignment method The liquid crystal alignment agent (AL-21) prepared in (1) above was applied on each electrode surface of two glass substrates having ITO electrodes using a spin coater. After coating and heating on a hot plate at 80° C. for 1 minute, heating was performed for 30 minutes in an oven at 230° C. in which the interior was replaced with nitrogen to form a coating film with an average thickness of 100 nm. The surface of this coating film is subjected to photo-alignment treatment by irradiating 20 mJ/cm ² of ultraviolet light including a linearly polarized bright line of 313 nm from a direction inclined at 40 degrees from the normal line of the substrate using a Hg-Xe lamp. An alignment film was formed.

(3) Manufacture of VA type liquid crystal display element Aluminum oxide spheres with a diameter of 3.5 μm are placed on the outer periphery of the surface of one of the substrates prepared in (2) above that has a liquid crystal alignment film, leaving a liquid crystal injection port. After applying the epoxy resin adhesive with a dispenser, the surfaces of the pair of substrates with the liquid crystal alignment film are placed opposite each other, and the substrates are pressed together so that the projection direction of the optical axis of the ultraviolet rays onto the substrate surface is antiparallel to each other, and the temperature is increased to 150°C. The adhesive was heat cured for 1 hour.
Next, a negative nematic liquid crystal (MLC-6608, manufactured by Merck) was filled into the gap between the substrates through a liquid crystal injection port, and then the liquid crystal injection port was sealed with an epoxy adhesive. Furthermore, in order to remove the fluid orientation during injection of the liquid crystal, it was heated at 120° C. and then slowly cooled to room temperature. Next, a VA type liquid crystal display element is manufactured by pasting polarizing plates on both outer sides of the substrate so that their polarization directions are perpendicular to each other and form an angle of 45° with the alignment treatment direction of the liquid crystal alignment film. did.

(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 was evaluated as "good".

(5) Evaluation of mechanical properties (keystroke test resistance) The VA type liquid crystal display element manufactured in (3) above was evaluated for mechanical properties (keystroke test resistance) in the same manner as in Example 1. As a result, this example was evaluated as "good".

(6) Evaluation of reliability The VA type liquid crystal display element manufactured in the above (3) was evaluated for reliability in the same manner as in Example 1. As a result, this example was evaluated as "excellent".

In Table 4, the mass ratio of each component of the liquid crystal aligning agent shows the blending ratio (parts by mass) of each compound with respect to the total 100 parts by mass of the polymer components used for preparing the liquid crystal aligning agent.

[Examples 11 to 14, Comparative Example 12]
In the above Example 1, a liquid crystal aligning agent was prepared in the same manner as in Example 1 except that the polymer and crosslinking agent to be contained in the liquid crystal aligning agent were changed as shown in Table 5 below, and the liquid crystal aligning agent was aligned by a photo alignment method. Along with forming the film, an FFS type liquid crystal display element and an ECB type liquid crystal display element were manufactured and various evaluations were performed. The evaluation results are shown in Table 5 below.

As shown in Tables 3 to 5, the liquid crystal aligning agents of Examples 1 to 14 containing the polymer (P) and the compound (C) have all of the liquid crystal alignment, mechanical properties, and reliability of the liquid crystal display element. It was rated as ``excellent'' or ``good,'' and various properties were excellent. On the other hand, the liquid crystal aligning agents of Comparative Examples 1 to 12 that do not contain the polymer (P) or the compound (C) are "poor" in at least one of the liquid crystal alignment and mechanical properties of the liquid crystal display element, It was inferior to the example.

Although the mechanism by which the mechanical properties of the liquid crystal display elements were improved in Examples 1 to 14 is not clear, it is presumed as follows. Polymers (PI-1, PI-2) and polymers (PA-1 to PA-5) all have a large number of carboxyl groups in their molecules, and in the compound (C) that functions as a crosslinking agent. It is thought that an intermolecular crosslinked structure (esterification) is formed with the reactive functional group (hydroxy group or its acetal protected form).

In compound (C), at least a part of the highly polar hydroxy group is protected by an acetal structure, and the polarity is lowered (hydrophobized) compared to the crosslinking agent used in Comparative Examples 2 and 4 to 7. . Therefore, the surface free energy tends to be smaller than that of the polymer (P) contained in the liquid crystal alignment agent, and it is presumed 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.

In addition, compound (C) has a thermal latent property, and it is considered that the protective group is gradually removed by heat and crosslinking progresses. Therefore, when forming a liquid crystal alignment film, phase separation between compound (C) and the polymer may proceed before the compound (C) reacts with the polymer, and compound (C) may become unevenly distributed near the film surface. There is. On the other hand, the crosslinking agents used in Comparative Examples 2 and 4 to 7 are highly polar and easily miscible with the polymer, and the crosslinking agent used in Comparative Example 3 has low thermal stability of the protecting group and is heavily polymerized during the baking process. It is presumed that uneven distribution of the crosslinking agent is less likely to occur due to coalescence and rapid formation of crosslinks.

The keystroke test resistance of a liquid crystal display element reflects the abrasion resistance of the film surface, and in Examples 1 to 14, the crosslinking agent was unevenly distributed on the film surface, promoting crosslinking near the film surface and improving mechanical strength. It is considered that because of the selective improvement, the mechanical properties of the liquid crystal alignment film were improved compared to the crosslinking agents used in Comparative Examples 2 to 7. If the abrasion resistance of the film surface is low, the liquid crystal alignment films will rub against each other due to various stresses applied to the liquid crystal display element (glass polishing, vibration, keystrokes/finger presses, etc.) and wear out, causing the liquid crystal to deteriorate in the scratched areas. It is known that fine bright spot defects may occur due to poor orientation or abrasion particles.

Furthermore, in Examples 3, 4, 6, and 8, a crosslinking agent having an amino group protected by a Boc group was contained as a compound (C), and the reliability of the liquid crystal display element was " "Excellent" and especially excellent. Although the mechanism by which reliability has been improved is not clear, it is presumed as follows.

It is known that a liquid crystal composition having an alkenyl structure or the like is oxidatively decomposed by light irradiation, producing acidic decomposition products such as formic acid, which may deteriorate the electrical characteristics and reliability of a liquid crystal display element. In the compound (C) that further has -NH- protected by a Boc group, -NH- (basic functional group) is generated by deprotection by heat, so that acidic decomposition products derived from liquid crystals can be captured. Guessed. Furthermore, when using a photoalignment method that utilizes a photolysis reaction of a cyclobutane ring, it is possible that the amino group generated by heat forms a crosslinked structure through a Michael addition reaction with the maleimide derivative of the photolysis product. By crosslinking the polymer of the liquid crystal alignment film with a crosslinking agent, the swelling of the film by the liquid crystal is suppressed, and the transfer of substances such as impurity ions incorporated into the film is suppressed, contributing to improvement of voltage holding rate. It is presumed that

On the other hand, the liquid crystal aligning agent of Comparative Example 12 contains the compound (C) but does not contain the polymer (P) having a carboxy group, and the keying test resistance of the liquid crystal display element and the abrasion resistance of the liquid crystal alignment film are improved. It was "defective". This result is considered to be due to the lack of reaction sites that form a crosslinking reaction with compound (C) in the polymer, and the effect of improving mechanical properties was not expressed.

From the above, according to the liquid crystal aligning agent containing the polymer (P) and the compound (C), it is possible to improve the mechanical properties of the liquid crystal aligning film while maintaining good liquid crystal alignment, and to produce a highly reliable liquid crystal element. It is presumed that it was obtained.

Claims (12)

A polymer (P) having a carboxyl group,
A group represented by “-OX ¹ ” (wherein, X ¹ is a hydrogen atom or a thermally releasable group) is present in one molecule, and a group represented by “-OX ¹ ” is A compound (C) in which one or more of the above X ¹ is a monovalent group having a tetrahydropyran ring structure or a tetrahydrofuran ring structure;
A liquid crystal aligning agent containing. The liquid crystal aligning agent according to claim 1, wherein the compound (C) has a partial structure represented by the following formula (1).

(In formula (1), X ¹ is a hydrogen atom or a thermally releasable group ^. R ^1a is a hydrogen atom or a monovalent organic group having 1 to 4 carbon atoms ^. It is a hydrogen atom or a monovalent organic group having 1 to 8 carbon atoms. "*" represents a bond.) The liquid crystal aligning agent according to claim 1, wherein the compound (C) is a compound represented by the following formula (2).

(In formula (2), X ¹ is a hydrogen atom or a thermally releasable group. However, the four X ^1s in the formula are the same or different, and one or more of the four X ^1s is a tetrahydropyran ring. ( ^R2 is a divalent organic group.) The liquid crystal aligning agent according to claim 1, wherein the compound (C) has a group represented by "-NY ¹ -" (wherein Y ¹ is a thermally releasable group). The liquid crystal aligning agent according to claim 1, wherein the X ¹ is a hydrogen atom, a substituted or unsubstituted 2-tetrahydropyranyl group, or a substituted or unsubstituted 2-tetrahydrofuranyl group. The liquid crystal aligning 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. The polymer (P) is selected from the group consisting of a partial structure represented by the following formula (3), a partial structure represented by the following formula (4), and a partial structure represented by the following formula (5). The liquid crystal aligning agent according to claim 6, comprising a polymer having at least one type.

(In formulas (3) to (5), Z ¹ is a tetravalent organic group. Z ² is a divalent organic group. Z ³ is a divalent organic group having a carboxy group. R ³ and R ⁴ are each independently a monovalent organic group.) The liquid crystal aligning agent according to claim 1, wherein the content ratio of the compound (C) is 0.1 to 50 parts by mass based on a total of 100 parts by mass of polymer components contained in the liquid crystal aligning agent. A liquid crystal aligning film formed using the liquid crystal aligning agent according to any one of claims 1 to 8. A liquid crystal element comprising the liquid crystal alignment film according to claim 9. A polymer (P) having a carboxyl group,
A group represented by “-OX ¹ ” (wherein, X ¹ is a hydrogen atom or a thermally releasable group) is present in one molecule, and a group represented by “-OX ¹ ” is A compound (C) in which one or more of the above X ¹ is a monovalent group having a tetrahydropyran ring structure or a tetrahydrofuran ring structure;
A thermosetting composition containing. A compound represented by the following formula (2).

(In formula (2), X ¹ is a hydrogen atom or a thermally releasable group. However, the four X ^1s in the formula are the same or different, and one or more of the four X ^1s is a tetrahydropyran ring. ( ^R2 is a divalent organic group.)

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