JP6870377B2 - Liquid crystal alignment agent, liquid crystal alignment film and its manufacturing method, and liquid crystal element - Google Patents

Description

The present invention relates to a liquid crystal aligning agent, a liquid crystal alignment film and a method of manufacturing the same, and relates to a liquid crystal element.

In recent years, large-screen, high-definition LCD televisions have become the mainstream, and small display terminals such as smartphones and tablet PCs have become widespread, and the demand for high-definition LCD panels is increasing. Based on this background, various liquid crystal alignment agents have been proposed in order to improve the display quality of the liquid crystal panel (see, for example, Patent Document 1). Patent Document 1 describes reduction of afterimages by using a polyamic acid made from a diamine having an amino group protected by a heat-desorbing group in the molecule as a raw material and a derivative thereof as a polymer component of a liquid crystal alignment agent. It is disclosed that the plan is to be taken.

Japanese Unexamined Patent Publication No. 2012-193167

With the increasing versatility of liquid crystal panels, it is expected that liquid crystal panels will be used in harsher environments than before. One is light stress. For example, the liquid crystal panel is exposed to the backlight for a longer time than before due to a long period of use or continuous driving for a long time, or it is exposed to ultraviolet rays outdoors. May be used in. In such a usage pattern, the liquid crystal element tends to deteriorate, and there is a concern that the display performance cannot be guaranteed for a long period of time. Further, when the liquid crystal element is used in a harsh environment, the liquid crystal alignment film is easily peeled off from the substrate, and when the film is peeled off from the substrate, there is a concern that the display quality of the liquid crystal element is deteriorated.

The present invention has been made in view of the above problems, and one object of the present invention is to provide a liquid crystal alignment agent capable of improving the reliability of a liquid crystal element with respect to light and the adhesion of a film to a substrate.

As a result of diligent studies to achieve the above-mentioned problems of the prior art, the present inventors can solve the above-mentioned problems by using a polymer having a specific structure as a polymer component of a liquid crystal aligning agent. The present invention has been completed. Specifically, the following means are provided.

（式（１）及び式（２）中、Ｑ^１は、下記式（３）で表される４価の有機基であり、Ｑ^２は２価の有機基であり、Ｒ^１及びＲ^２は、それぞれ独立に、水素原子又は１価の有機基である。）

（式（３）中、Ａ^１及びＡ^２は、それぞれ独立に芳香環基又はシクロヘキサン環から３個の水素原子を取り除いた基であり、Ｒ^３は、炭素数１〜１８個の２価の有機基であり、Ｒ^４及びＲ^５は、それぞれ独立に水素原子又は１価の有機基であり、Ｒ^４とＲ^５とが結合して、Ｒ^４が結合する窒素原子、Ｒ^５が結合する窒素原子及びＲ^３とともに環が形成されていてもよい。「＊」は、カルボニル基に結合する結合手を示す。） <1> A liquid crystal alignment agent containing a polymer [A] having at least one selected from the group consisting of a partial structure represented by the following formula (1) and a partial structure represented by the following formula (2).

(In the formulas (1) and (2) , Q ¹ is a tetravalent organic group represented by the following formula (3), Q ² is a divalent organic group, and R ¹ and R ² are. , Each independently is a hydrogen atom or a monovalent organic group.)

(In the formula (3), A ¹ and A ² are groups in which ^three hydrogen atoms are independently removed from the aromatic ring group or the cyclohexane ring, respectively, and R 3 is a divalent group having 1 to 18 carbon atoms. an organic group, R ⁴ and R ⁵ are each independently a hydrogen atom or a monovalent organic group, by bonding R ⁴ and R ^5, the nitrogen atom to which R ⁴ is attached, R ⁵ is attached together with the nitrogen atom and R ³ may be ring is formed. "*" indicates a bond that binds to the carbonyl group.)

（式（４）中、Ａ^１及びＡ^２は、それぞれ独立に芳香環基又は脂環式基であり、Ｒ^３は、炭素数１〜１８個の２価の有機基である。ただし、Ｒ^３は、Ｒ^３に隣接する２個の窒素原子の少なくとも一方に対して、カルボニル基、メチレン基、脂環式基、芳香環基又は複素環基で結合している。Ｒ^４及びＲ^５は、それぞれ独立に水素原子又は１価の有機基であり、Ｒ^４とＲ^５とが結合して、Ｒ^４が結合する窒素原子、Ｒ^５が結合する窒素原子及びＲ^３とともに環が形成されていてもよい。） <2> A liquid crystal alignment film formed by using the liquid crystal alignment agent of <1> above.
<3> A liquid crystal element provided with the liquid crystal alignment film of <2> above.
<5> A polymer having at least one selected from the group consisting of the partial structure represented by the above formula (1) and the partial structure represented by the above formula (2). However, R ³ is ^{bonded to at least one of the two nitrogen atoms adjacent to R 3} with a carbonyl group, a methylene group, an alicyclic group, an aromatic ring group or a heterocyclic group.
<6> A compound represented by the following formula (4).

(In the formula (4), A ¹ and A ² are independently aromatic ring groups or alicyclic groups, and R ³ is a divalent organic group having 1 to 18 carbon atoms, respectively. ³ is ^{bonded to at least one of the two nitrogen atoms adjacent to R 3} with a carbonyl group, a methylene group, an alicyclic group, an aromatic ring group or a heterocyclic group. R ⁴ and R ⁵ are bonded. , Are independently hydrogen atoms or monovalent organic groups, and R ⁴ and R ⁵ are bonded to form a ring together with the ^{nitrogen atom to which R 4} is bonded, the nitrogen atom to which R ⁵ is bonded, and R ^3. May be.)

According to the liquid crystal alignment agent containing the polymer [A], a liquid crystal alignment film having good adhesion to the substrate can be formed. Further, it is possible to obtain a liquid crystal element having good reliability with respect to light.

The schematic block diagram of the FFS type liquid crystal display element. The plan view of the top electrode used for manufacturing a liquid crystal display element by a rubbing method. (A) is a top view of the top electrode, and (b) is a partially enlarged view of the top electrode. The figure which shows the drive electrode of 4 systems.

Hereinafter, each component contained in the liquid crystal alignment agent of the present disclosure, and other components optionally blended will be described.

≪Polymer [A] ≫
The liquid crystal alignment agent of the present disclosure contains a polymer [A] having at least one selected from the group consisting of the partial structure represented by the above formula (1) and the partial structure represented by the above formula (2). This polymer [A] has a skeleton represented by the above formula (3) in ^{Q 1} in the above formula (1) and the above formula (2).

Here, the term "organic group" as used herein is a concept including a group of reactive or non-reactive atoms contained in an organic compound and a single atom that imparts reactivity to the organic compound. Therefore, the organic group may be an atomic group of hydrocarbons, an atomic group containing a hetero atom in the structure, or a hetero atom.
"Hydrocarbon group" means to include a chain hydrocarbon group, an alicyclic hydrocarbon group and an aromatic hydrocarbon group. The "chain hydrocarbon group" means a linear or branched hydrocarbon group which does not contain a cyclic structure and is composed only of a chain structure. The "alicyclic hydrocarbon group" means a hydrocarbon group containing only the alicyclic hydrocarbon structure as the ring structure. However, it does not have to be composed only of the alicyclic hydrocarbon structure, and may have a chain structure as a part thereof. The "aromatic hydrocarbon group" means a hydrocarbon group containing an aromatic ring structure as a ring structure. However, it does not have to be composed of only an aromatic ring structure, and a chain structure or an alicyclic hydrocarbon structure may be included in a part thereof.
"Tetracarboxylic acid derivative" means to include tetracarboxylic dianhydride, tetracarboxylic acid diester and tetracarboxylic acid diester dihalide.

In the above formula (3), A ¹ and A ² are independently aromatic ring groups or alicyclic groups, respectively. Examples of the aromatic ring group of A ¹ and A ² include a group obtained by removing three hydrogen atoms from the ring portion of an aromatic ring such as a benzene ring, a naphthalene ring, and an anthracene ring. Preferably, ^{the aromatic ring groups of A 1} and A ² are groups obtained by removing three hydrogen atoms from the benzene ring. Examples of the alicyclic group include a group obtained by removing three hydrogen atoms from the ring portion of an aliphatic ring such as a cyclopentane ring and a cyclohexane ring. Preferably, ^{the aliphatic ring groups A 1} and A ² are groups obtained by removing three hydrogen atoms from the cyclohexane ring. From the viewpoint of reliability of the liquid crystal device, A ¹ and A ² are preferably aromatic ring groups, and more preferably groups obtained by removing three hydrogen atoms from the benzene ring.

（式（３−１）中、Ｒ^６は、炭素数１〜１６個の２価の有機基である。Ａ^１、Ａ^２、Ｒ^４及びＲ^５は、それぞれ上記式（３）と同義である。「＊」は、カルボニル基に結合する結合手を示す。） As the ^{divalent organic group of R 3,} a divalent hydrocarbon group having 1 to 18 carbon atoms and at least one methylene group of the hydrocarbon group are -O-, -CO-, -COO-, -NH-. , -NH-CO-, -S-, etc., a divalent group having 1 to 18 carbon atoms substituted with a functional group, and at least one hydrogen atom of the hydrocarbon group is a halogen atom (fluorine atom, chlorine atom, bromine). (Atomic, iodine atom, etc.), a divalent group having 1 to 18 carbon atoms substituted with a substituent such as a cyano group, a group having a heterocycle, and the like can be mentioned.
Among the above, R ^{3 may be bonded to at least one of the two nitrogen atoms adjacent to R 3} with a carbonyl group, a methylene group, an alicyclic group, an aromatic ring group or a heterocyclic group. It is more preferable that both of the two nitrogen atoms are bonded with a carbonyl group, a methylene group, an alicyclic group, an aromatic ring group or a heterocyclic group, respectively. In this case, the groups bonded to the two adjacent nitrogen atoms may be the same or different. Particularly preferably, R ³ has a structure in which two nitrogen atoms are bonded to each other by a carbonyl group. That is, Q ¹ is preferably a group represented by the following formula (3-1).

(In the formula (3-1), R ⁶ is a divalent organic group having ^{1 to} 16 carbon atoms. A 1, A ² , R ⁴ and R ⁵ are synonymous with the above formula (3), respectively. Yes. "*" Indicates a bond that binds to a carbonyl group.)

In the above formula (3-1), the ^{divalent organic group of R 6} is a divalent chain hydrocarbon group having 1 to 16 carbon atoms, a divalent alicyclic hydrocarbon group having 3 to 16 carbon atoms, and the like. Alternatively, it is preferably a divalent aromatic hydrocarbon group having 6 to 16 carbon atoms.

In the above formulas (3) and (3-1) ^{, examples of the monovalent organic group of R 4} and R ⁵ include a divalent hydrocarbon group having 1 to 10 carbon atoms, a protecting group and the like. When R ⁴ and R ⁵ are protecting groups, they are preferably carbamate-based protecting groups, and specific examples thereof include, for example, tert-butoxycarbonyl group, benzyloxycarbonyl group, and 1,1-dimethyl-2-haloethyloxy. Examples thereof include a carbonyl group, an allyloxycarbonyl group and a 2- (trimethylsilyl) ethoxycarbonyl group. Of these, the tert-butoxycarbonyl group is particularly preferred. R ⁴ and R ⁵ are preferably a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or a protecting group, and more preferably a protecting group from the viewpoint of solubility of the polymer [A] in a solvent.
R ⁴ and R ⁵ may form a ring ^{with R 4} and R ⁵ bonded together with ^{a nitrogen atom to which R 4} is bonded, a nitrogen atom to which R ⁵ is bonded, and R ³ . Examples of the ring in this case include nitrogen-containing heterocycles such as piperazine, homopiperazine, and pyrazine.

The formula (1), in the formula (2), the divalent organic group Q ² is a residue obtained by removing the two primary amino groups of the diamine compound. Examples of the monovalent organic group of R ¹ and R ² include an alkyl group having 1 to 20 carbon atoms, a fluoroalkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, and 4 to 20 carbon atoms. Cycloalkylalkyl groups, alkylcycloalkyl groups having 4 to 20 carbon atoms, aryl groups having 6 to 20 carbon atoms, aralkyl groups having 7 to 20 carbon atoms, alkoxysilyl groups, monovalent groups having a cinnamic acid structure, and the like can be mentioned. Be done.

The polymer [A] is a polymer having a polyamic acid, a polyamic acid ester, or a polyimide as a main skeleton, and can be obtained by a synthesis method according to the main skeleton. When the polymer [A] is a polyamic acid, for example, a tetracarboxylic dianhydride containing a compound represented by the above formula (4) (hereinafter, also referred to as "specific acid dianhydride"), and a diamine compound. Can be obtained by reacting.

For certain dianhydride, description of ^{A 1, A 2, R 3} ~R 5 in the formula (4), the above equation (3), ^A 1 in the formula ^{(3-1), A} 2, R description of ³ to R ⁵ are applied respectively.
Specific examples of the specific acid dianhydride include compounds represented by the following formulas (4-1) to (4-17). As the specific acid dianhydride, one type may be used alone, or two or more types may be used in combination.

（式（６）中、Ｘ^１及びＸ^２はハロゲン原子であり、Ｒ^６は、上記式（３−１）と同義である。式（７）中、Ａは、芳香環基又は脂環式基である。式（４−ａ−１）、式（４−ａ−２）及び式（４−ａ）中、Ａ^１、Ａ^２、Ｒ^４〜Ｒ^６は、上記式（３−１）と同義である。） The specific acid dianhydride can be synthesized by appropriately combining the conventional methods of organic chemistry according to ^{R 3} in the above formula (3). ^{For example, when Q 1} in the above formulas (1) and (2) is a group represented by the above formula (3-1), for example, an acid halide represented by the following formula (6). The compound and the amine compound represented by the following formula (7) are reacted, preferably in an organic solvent in the presence of a catalyst, if necessary, and then the obtained reaction product (4-a-1). A specific acid dianoxide can be obtained by carrying out the deprotection and dehydration ring closure reaction of the above. Further, a specific acid dianhydride can also be obtained by using a dialdehyde compound and an amine compound represented by the following formula (7) as raw materials. However, the method for synthesizing the specific acid dianhydride is not limited to the above.

(In the formula (6), X ¹ and X ² are halogen atoms, and R ⁶ is synonymous with the above formula (3-1). In the formula (7), A is an aromatic ring group or an alicyclic formula. In the formula (4-a-1), the formula (4-a-2) and the formula (4-a), A ¹ , A ² , R ^{4 to} R ⁶ are the above formula (3-1). Is synonymous with.)

In the synthesis of the polyamic acid as the polymer [A], only the specific acid dianhydride may be used as the tetracarboxylic dianhydride, but other tetracarboxylic dianhydrides other than the specific acid dianhydride may be used. You may use it. Specific examples of other tetracarboxylic dianhydrides include aliphatic tetracarboxylic dianhydrides such as butanetetracarboxylic dianhydride and ethylenediaminetetraacetic acid dianhydride;

Examples of the alicyclic tetracarboxylic dianhydride include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, and the like. 2,3,5-tricarboxycyclopentylacetic dianhydride, 5- (2,5-dioxotetrakitetra-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, 3,5,6-tricarboxy-2-carboxymethylnorbornan-2: 3,5: 6-dianhydride, 2,4,6,8-tetracarboxybicyclo [3.3.0] octane-2: 4 , 6: 8-dianhydride, cyclopentanetetracarboxylic dianhydride, cyclohexanetetracarboxylic dianhydride, etc.;
Examples of aromatic tetracarboxylic dianhydrides include pyromellitic dianhydride, 4,4'-(hexafluoroisopropyridene) diphthalic anhydride, p-phenylenebis (trimellitic acid monoester anhydride), and ethylene glycol. Bis (anhydrotrimellitic acid), 1,3-propylene glycol bis (anhydrotrimellitic acid), etc. can be mentioned, respectively; and the tetracarboxylic dianhydride described in JP-A-2010-97188 can be used. Can be used. For other tetracarboxylic dianhydrides, one of these can be used alone or in combination of two or more.

When synthesizing a polyamic acid as a polymer [A], an alicyclic tetracarboxylic dianhydride is used as another tetracarboxylic dianhydride because the solubility of the polymer [A] in a solvent can be improved. Is preferable. As a result, as the polymer [A], the structural unit derived from the specific acid dianhydride and the structural unit derived from the alicyclic tetracarboxylic acid derivative having no partial structure represented by the above formula (3) can be obtained. A polymer having is obtained.
When an alicyclic tetracarboxylic dianhydride is used as the other tetracarboxylic dianhydride, the ratio of the alicyclic tetracarboxylic dianhydride used is 5 mol% with respect to the total amount of the tetracarboxylic dianhydride used for the synthesis of polyamic acid. The above is preferable, the content is more preferably 10 mol% or more, further preferably 15 to 95 mol%, and particularly preferably 20 to 85 mol%.

The ratio of the specific acid dianhydride used is preferably 5 mol% or more, more preferably 10 mol% or more, and 20 mol%, based on the total amount of the tetracarboxylic dianhydride used for the synthesis. The above is more preferable. The upper limit of the usage ratio of the specific acid dianhydride is not particularly limited, but when other tetracarboxylic dianhydrides are used in combination, it is preferably 95 mol% or less, more preferably 90 mol% or less. It is more preferably 85 mol% or less, and particularly preferably 80 mol% or less.

The diamine compound used in the synthesis of the polyamic acid is not particularly limited. Specific examples include, for example, metaxylylenediamine, ethylenediamine, 1,3-propanediamine, tetramethylenediamine, hexamethylenediamine and the like as aliphatic diamines; and for example, p-cyclohexanediamine, 4,4 as alicyclic diamines. '-Methylenebis (cyclohexylamine) etc.;

（式（Ｅ−１）中、Ｘ^I及びＸ^IIは、それぞれ独立に、単結合、−Ｏ−、−ＣＯＯ−又は−ＯＣＯ−であり、Ｒ^Ｉは炭素数１〜３のアルカンジイル基であり、Ｒ^ＩＩは単結合又は炭素数１〜３のアルカンジイル基であり、ａは０又は１であり、ｂは０〜２の整数であり、ｃは１〜２０の整数であり、ｄは０又は１である。ただし、ａ及びｂが同時に０になることはない。）
で表される化合物等の側鎖型ジアミン：
ｐ−フェニレンジアミン、４，４’−ジアミノジフェニルメタン、４，４’−エチレンジアニリン、４，４’−ジアミノジフェニルアミン、４，４’−ジアミノジフェニルスルフィド、４−アミノフェニル−４’−アミノベンゾエート、４，４’−ジアミノアゾベンゼン、３，５−ジアミノ安息香酸、１，２−ビス（４−アミノフェノキシ）エタン、１，５−ビス（４−アミノフェノキシ）ペンタン、ビス［２−（４−アミノフェニル）エチル］ヘキサン二酸、ビス（４−アミノフェニル）アミン、Ｎ，Ｎ−ビス（４−アミノフェニル）メチルアミン、１，４−ビス（４−アミノフェニル）−ピペラジン、Ｎ，Ｎ’−ビス（４−アミノフェニル）−ベンジジン、２，２’−ジメチル−４，４’−ジアミノビフェニル、２，２’−ビス（トリフルオロメチル）−４，４’−ジアミノビフェニル、４，４’−ジアミノジフェニルエーテル、２，２−ビス［４−（４−アミノフェノキシ）フェニル］プロパン、４，４’−（フェニレンジイソプロピリデン）ビスアニリン、１，４−ビス（４−アミノフェノキシ）ベンゼン、４−（４−アミノフェノキシカルボニル）−１−（４−アミノフェニル）ピペリジン、４，４’−［４，４’−プロパン−１，３−ジイルビス（ピペリジン−１，４−ジイル）］ジアニリン等の非側鎖型ジアミンを；
ジアミノオルガノシロキサンとして、例えば、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を；それぞれ挙げることができるほか、特開２０１０−９７１８８号公報に記載のジアミン化合物を用いることができる。 Examples of aromatic diamines include dodecanoxidiaminobenzene, hexadecanoxidiaminobenzene, octadecanoxidiaminobenzene, cholestanyloxydiaminobenzene, cholesteryloxydiaminobenzene, cholestanyl diaminobenzoate, cholesteryl diaminobenzoate, and diaminobenzoic acid. Ranostanyl, 3,6-bis (4-aminobenzoyloxy) cholesterol, 3,6-bis (4-aminophenoxy) cholesterol, 1,1-bis (4-((aminophenyl) methyl) phenyl) -4-butyl Cyclohexane, 2,5-diamino-N, N-diallylaniline, the following formula (E-1)

(In the formula (E-1), X ^I and X ^II is independently a single bond, -O -, - COO- or a -OCO-, ^{R I} is alkanediyl group having 1 to 3 carbon atoms Yes, R ^II is a single bond or an alkanediyl group with 1-3 carbon atoms, a is 0 or 1, b is an integer 0-2, c is an integer 1-20, d is It is 0 or 1. However, a and b cannot be 0 at the same time.)
Side chain diamines such as compounds represented by:
p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-ethylenedianiline, 4,4'-diaminodiphenylamine, 4,4'-diaminodiphenylsulfide, 4-aminophenyl-4'-aminobenzoate, 4,4'-Diaminoazobenzene, 3,5-diaminobenzoic acid, 1,2-bis (4-aminophenoxy) ethane, 1,5-bis (4-aminophenoxy) pentane, bis [2- (4-amino) Phenyl) ethyl] hexanedioic acid, bis (4-aminophenyl) amine, N, N-bis (4-aminophenyl) methylamine, 1,4-bis (4-aminophenyl) -piperazin, N, N'- Bis (4-aminophenyl) -benzidine, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-bis (trifluoromethyl) -4,4'-diaminobiphenyl, 4,4'- Diaminodiphenyl ether, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 4,4'-(phenylenediisopropylidene) bisaniline, 1,4-bis (4-aminophenoxy) benzene, 4-( Non-sides of 4-aminophenoxycarbonyl) -1- (4-aminophenyl) piperidine, 4,4'-[4,4'-propane-1,3-diylbis (piperidin-1,4-diyl)] dianiline, etc. Chain diamine;
Examples of the diaminoorganosiloxane include 1,3-bis (3-aminopropyl) -tetramethyldisiloxane; and the diamine compound described in JP-A-2010-97188 can be used. ..

ジアミン化合物は、これらの１種を単独で又は２種以上を組み合わせて使用することができる。 Specific examples of the compound represented by the above formula (E-1) include compounds represented by the following formulas (E-1-1) and (E-1-2), respectively.

As the diamine compound, one of these can be used alone or in combination of two or more.

(Synthesis of polyamic acid)
The polyamic acid can be obtained by reacting the tetracarboxylic dianhydride as described above with a diamine compound, if necessary, with a molecular weight modifier (for example, acid monoanhydride, monoamine compound, monoisocyanate compound, etc.). Can be done. The ratio of the tetracarboxylic dianhydride used in the polyamic acid synthesis reaction to the diamine compound is 0.2 for the acid anhydride group of the tetracarboxylic dianhydride with respect to 1 equivalent of the amino group of the diamine compound. A ratio of up to 2 equivalents is preferable.

The polyamic acid synthesis reaction is preferably carried out in an organic solvent. The reaction temperature at this time is preferably −20 ° C. to 150 ° C., and the reaction time is preferably 0.1 to 24 hours. Examples of the organic solvent used in the reaction include aprotic polar solvents, phenolic solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons, hydrocarbons and the like. Particularly preferred organic solvents are N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide, m-cresol, xylenol. One or more selected from the group consisting of and halogenated phenol is used as a solvent, or one or more of these is mixed with another organic solvent (for example, butyl cellosolve, diethylene glycol diethyl ether, etc.). The amount of the organic solvent used is preferably such that the total amount of the tetracarboxylic dianhydride and the diamine compound is 0.1 to 50% by mass with respect to the total amount of the reaction solution. The reaction solution obtained by dissolving the polyamic acid may be used as it is for the preparation of the liquid crystal alignment agent, or the polyamic acid contained in the reaction solution may be isolated and then used for the preparation of the liquid crystal alignment agent.

The polyamic acid ester as the polymer [A] is, for example, [I] a method of reacting the polyamic acid obtained above with an esterifying agent (for example, methanol, ethanol, N, N-dimethylformamide diethylacetal, etc.). [II] Tetracarboxylic acid diester and diamine compound, preferably in an organic solvent, with a suitable dehydration catalyst (eg 4- (4,6-dimethoxy-1,3,5-triazine-2-yl) -4-methyl). A method of reacting in the presence of morpholinium halide, carbonyl imidazole, phosphorus-based condensing agent, etc., [III] a tetracarboxylic acid diester dihalide and a diamine compound, preferably in an organic solvent, with a suitable base (eg, pyridine, etc.). It can be obtained by a method of reacting in the presence of a tertiary amine such as triethylamine or an alkali metal such as sodium hydride, potassium hydride, sodium hydroxide, potassium hydroxide, sodium or potassium). The polyamic acid ester contained in the liquid crystal alignment agent may have only an amic acid ester structure, or may be a partial esterified product in which the amic acid structure and the amic acid ester structure coexist. When the polyamic acid ester is obtained as a solution by the above reaction, the solution may be used as it is for the preparation of the liquid crystal alignment agent, and the polyamic acid ester contained in the reaction solution is isolated and then the liquid crystal alignment agent is used. It may be used for preparation.

The polyimide as the polymer [A] can be obtained, for example, by dehydrating, ring-closing and imidizing the polyamic acid synthesized as described above. The polyimide may be a completely imidized product in which all of the amic acid structure possessed by the precursor polyamic acid is dehydrated and ring-closed, and only a part of the amic acid structure is dehydrated and ring-closed to form the amic acid structure and the imide. It may be a partially imidized product in which a ring structure coexists. The polyimide used in the reaction preferably has an imidization ratio of 20 to 99%, more preferably 30 to 90%. This imidization ratio is expressed as a percentage of the ratio of the number of imide ring structures to the total of the number of amic acid structures and the number of imide ring structures of polyimide. Here, a part of the imide ring may be an isoimide ring.

The dehydration ring closure of the polyamic acid is preferably carried out by a method in which the polyamic acid is dissolved in an organic solvent, a dehydrating agent and a dehydration ring closure catalyst are added to the solution, and heating is performed as necessary. As the dehydrating agent, 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 with respect to 1 mol of the amic acid structure of the polyamic acid. As the dehydration ring-closing catalyst, for example, tertiary amines such as pyridine, collagen, lutidine, and triethylamine can be used. The amount of the dehydration ring-closing catalyst used is preferably 0.01 to 10 mol with respect to 1 mol of the dehydrating agent used. Examples of the organic solvent used include organic solvents exemplified as those used for the synthesis of polyamic acids. The reaction temperature of the dehydration ring closure reaction is preferably 0 to 180 ° C., and the reaction time is preferably 1.0 to 120 hours. The reaction solution containing the polyimide thus obtained may be used as it is for the preparation of the liquid crystal alignment agent, or the polyimide may be isolated and then used for the preparation of the liquid crystal alignment agent.

The solution viscosity of the polymer [A] preferably has a solution viscosity of 10 to 800 mPa · s when made into a solution having a concentration of 10% by mass, and has a solution viscosity of 15 to 500 mPa · s. Is more preferable. The solution viscosity (mPa · s) is E for a polymer solution having a concentration of 10% by mass prepared using a good solvent of the polymer [A] (for example, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.). It is a value measured at 25 ° C. using a mold rotational viscometer.
The polystyrene-equivalent weight average molecular weight (Mw) of the polymer [A] measured by gel permeation chromatography (GPC) is preferably 1,000 to 500,000, more preferably 2,000 to 300,000. Is. The molecular weight distribution (Mw / Mn) represented by the ratio of Mw to the polystyrene-equivalent number average molecular weight (Mn) measured by GPC is preferably 15 or less, more preferably 10 or less. The polymer [A] contained in the liquid crystal alignment agent may be only one type or a combination of two or more types.

The polymer [A] may be a polymer exhibiting photo-orientation. In this case, since the liquid crystal alignment ability can be imparted to the coating film formed by using the liquid crystal alignment agent by the photoalignment treatment, uniform liquid crystal alignment is imparted to the photosensitive organic film while suppressing the generation of static electricity and dust. It is possible to do. Further, it is preferable in that precise control of the liquid crystal orientation direction is possible.

A polymer exhibiting photo-orientation can be obtained, for example, by polymerization using a monomer having a photo-orientation group. The photo-oriented group is a functional group that imparts anisotropy to the film by a photoisomerization reaction, a photodimerization reaction, a photodecomposition reaction, or a photofries rearrangement reaction by light irradiation. Specific examples of the photoorientating group include an azobenzene-containing group containing azobenzene or a derivative thereof as a basic skeleton, a katsura acid structure-containing group containing katsura acid or a derivative thereof as a basic skeleton, and a chalcone containing chalcone or a derivative thereof as a basic skeleton. Basically, a containing group, a benzophenone-containing group containing benzophenone or a derivative thereof as a basic skeleton, a coumarin-containing group containing coumarin or a derivative thereof as a basic skeleton, a phenylbenzoate-containing structure containing phenylbenzoate or a derivative thereof as a basic skeleton, cyclobutane or a derivative thereof. Examples thereof include a cyclobutane-containing structure contained as a skeleton, a bicyclo [3.3.0] octane-containing structure containing bicyclo [3.3.0] octane or a derivative thereof as a basic skeleton, and the like. When the polymer [A] is a polymer exhibiting photo-orientation, among the above, it is preferable that the polymer [A] exhibits photo-orientation by heating to 150 ° C. or higher after irradiation with polarized ultraviolet rays. Examples of such a polymer include a polymer having a synnamate group, a phenylbenzoate group, or the like as a photooriented group.

≪Other ingredients≫
The liquid crystal alignment agent of the present disclosure contains the polymer [A] as described above, but may contain other components if necessary. As other components, for example, a polymer having neither the partial structure represented by the above formula (1) nor the partial structure represented by the above formula (2) (hereinafter referred to as “other polymer”). , Compounds having at least one epoxy group in the molecule, functional silane compounds, photopolymerizable compounds, antioxidants, metal chelate compounds, curing accelerators, surfactants, fillers, dispersants, photosensitizers, etc. Can be mentioned. The main skeleton of the above other polymers is not particularly limited, and for example, polyamic acid, polyimide, polyamic acid ester, polyamide, polysiloxane, polyester, cellulose derivative, polyacetal, polystyrene derivative, poly (styrene-phenylmaleimide) derivative, Examples thereof include polymers having poly (meth) acrylate or the like as a main skeleton. The blending ratio of the other components can be appropriately selected according to each compound as long as the effects of the present disclosure are not impaired.

The content ratio of the polymer [A] in the liquid crystal alignment agent is a solid component (component other than the solvent) in the liquid crystal alignment agent from the viewpoint of sufficiently increasing the light resistance of the obtained liquid crystal element and the adhesion of the film to the substrate. It is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and further preferably 20 parts by mass or more with respect to 100 parts by mass in total.

In the polymer component of the liquid crystal alignment agent of the present disclosure, at least one selected from the group consisting of a nitrogen-containing heterocycle, a secondary amino group and a tertiary amino group in the same molecule as or different from the polymer [A]. It may contain a structural unit derived from the diamine compound (hereinafter, also referred to as "nitrogen-containing diamine"). By introducing such a nitrogen-containing structure into the polymer component, it is preferable in that the afterimage due to the application of the AC voltage can be further suppressed in the obtained liquid crystal element.

（式（５）中、Ｒ^７は水素原子又は炭素数１〜１０の１価の炭化水素基である。「＊」は炭化水素基に結合する結合手である。） Examples of the nitrogen-containing heterocycle contained in the nitrogen-containing diamine include pyrrole, imidazole, pyrazole, triazole, pyridine, pyrimidine, pyridazine, pyrazine, indole, benzoimidazole, purine, quinoline, isoquinoline, diazanaphthalene, quinoxaline, phthalazine, triazine, and carbazole. Examples thereof include acrydin, piperidine, piperazin, pyrrolidine, hexamethyleneimine and the like. Among them, at least one selected from the group consisting of pyridine, pyrimidine, pyrazine, piperidine, piperazine, quinoline, carbazole and acridine is preferable.
The secondary amino group and the tertiary amino group contained in the nitrogen-containing diamine can be represented by, for example, the following formula (5).

(In the formula (5), R ⁷ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. “*” Is a bond that binds to the hydrocarbon group.)

In the above formula (5), the ^{monovalent hydrocarbon group of R 7} is, for example, an alkyl group such as a methyl group, an ethyl group or a propyl group; an alkenyl group such as a vinyl group or an allyl group; a cycloalkyl group such as a cyclohexyl group. ; An aryl group such as a phenyl group and a methylphenyl group can be mentioned. R ⁷ is preferably a hydrogen atom or a methyl group. The nitrogen-containing diamine may have a group represented by the above formula (5) in the main chain or in the side chain.

Specific examples of the nitrogen-containing diamine include 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, 1 , 4-Bis- (4-aminophenyl) -piperazin, 3,6-diaminoacridine, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N, N'-bis ( 4-Aminophenyl) -benzidine, N, N'-bis (4-aminophenyl) -N, N'-dimethylbenzidine, 4- (4-aminophenoxycarbonyl) -1- (4-aminophenyl) piperidine, 4 , 4'-[4,4'-Propane-1,3-diylbis (piperidin-1,4-diyl)] dianiline, 2,4-diamino-N, N-diallylaniline, the following formula (5-1) to Examples thereof include compounds represented by each of the formulas (5-5).

The structural unit derived from the nitrogen-containing diamine may be contained in the polymer [A], may be contained in other polymers, or both the polymer [A] and the other polymer may have. You may have. When the polymer [A] has a structural unit derived from the nitrogen-containing diamine, the ratio of the nitrogen-containing diamine used is used for the synthesis of the polymer [A] from the viewpoint of sufficiently obtaining the effect of improving the afterimage characteristics of the liquid crystal element. It is preferably 1 mol% or more, more preferably 3 to 50 mol%, still more preferably 5 to 40 mol%, based on the total amount of the monomers. When the other polymer has a structural unit derived from the nitrogen-containing diamine, the ratio of the nitrogen-containing diamine used is preferably 1 mol% or more with respect to all the monomers used for the synthesis of the polymer. It is more preferably 3 to 80 mol%, further preferably 5 to 60 mol%. The nitrogen-containing diamine may be used alone or in combination of two or more.

<Solvent>
The liquid crystal alignment agent of the present disclosure is prepared as a liquid composition in which the polymer [A] and other components used as needed are preferably dispersed or dissolved in a suitable solvent.
Examples of the organic solvent used include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 1,2-dimethyl-2-imidazolidinone, γ-butyrolactone, γ-butyrolactam, N, N-dimethylformamide. , N, N-dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, Ethyl 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 Examples thereof include ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, diisopentyl ether, ethylene carbonate and propylene carbonate. These can be used alone or in admixture of two or more.

The solid content concentration in the liquid crystal alignment agent (the ratio of the total mass of the components other than the solvent of the liquid crystal alignment agent to the total mass of the liquid crystal alignment agent) is appropriately selected in consideration of viscosity, volatility, etc., but is preferable. It is in the range of 1 to 10% by mass. When the solid content concentration is less than 1% by mass, the film thickness of the coating film becomes too small and it becomes difficult to obtain a good liquid crystal alignment film. On the other hand, when the solid content concentration exceeds 10% by mass, the film thickness of the coating film becomes excessive and it is difficult to obtain a good liquid crystal alignment film, and the viscosity of the liquid crystal alignment agent increases and the coatability deteriorates. There is a tendency.

≪Liquid crystal alignment film and liquid crystal element≫
The liquid crystal alignment film of the present disclosure is formed by the liquid crystal alignment agent prepared as described above. Further, the liquid crystal element of the present disclosure includes a liquid crystal alignment film formed by using the liquid crystal alignment agent described above. The operation mode of the liquid crystal in the liquid crystal element is not particularly limited, and for example, TN (Twisted Nematic) type, STN (Super Twisted Nematic) type, VA (Vertical Alignment) type (including VA-MVA type, VA-PVA type, etc.) , IPS (In-Plane Switching) type, FFS (fringe field switching) type, OCB (Optically Compensated Bend) type and the like. The liquid crystal element can be manufactured, for example, by a method including the following steps 1 to 3. In step 1, the substrate used 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 alignment agent is applied onto the substrate, and preferably the coated surface is heated to form a coating film on the substrate. As the substrate, for example, glass such as float glass and soda glass; a transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, polycarbonate, and poly (aliphatic olefin) can be used. As the transparent conductive film provided on one surface of a substrate, NESA film (US PPG registered trademark) made of tin oxide (SnO _2), indium oxide - such as an ITO film made of tin oxide _{(In 2} O 3 -SnO ₂₎ the Can be used. When manufacturing a TN type, STN type or VA type liquid crystal element, two substrates provided with a patterned transparent conductive film are used. On the other hand, in the case of manufacturing an IPS type or FFS type liquid crystal element, a substrate provided with electrodes patterned in a comb tooth shape and a facing substrate not provided with electrodes are used. The liquid crystal alignment agent is applied to the substrate on the electrode forming surface, preferably by an offset printing method, a spin coating method, a roll coater method, or an inkjet printing method.

After the liquid crystal alignment agent is applied, preheating is preferably performed for the purpose of preventing the applied liquid crystal alignment agent from dripping. The pre-baking temperature is preferably 30 to 200 ° C., and the pre-baking time is preferably 0.25 to 10 minutes. Then, a firing (post-baking) step is carried out 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-baking temperature) at this time is preferably 80 to 300 ° C., and the post-baking time is preferably 5 to 200 minutes. The film thickness of the film thus formed 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, a treatment (alignment treatment) for imparting a liquid crystal alignment ability to the coating film formed in the above step 1 is performed. As a result, the alignment ability of the liquid crystal molecules is imparted to the coating film to form a liquid crystal alignment film. The orientation treatment includes a rubbing treatment that imparts liquid crystal orientation ability to the coating film by rubbing the coating film in a certain direction with a roll wrapped with a cloth made of fibers such as nylon, rayon, and cotton, and a coating film formed on the substrate. Examples thereof include a photo-alignment treatment in which the coating film is irradiated with light to impart a liquid crystal alignment ability to the coating film. When a vertically oriented liquid crystal element is manufactured, the coating film formed in the above step 1 can be used as it is as a liquid crystal alignment film, but the coating film may be subjected to an orientation treatment.

The light irradiation for photo-orientation includes a method of irradiating the coating film after the post-baking process, a method of irradiating the coating film after the pre-baking process and before the post-baking process, a pre-baking process and a post-baking process. At least one of them can be carried out by a method of irradiating the coating film while heating the coating film, or the like. As the radiation to irradiate the coating film, for example, ultraviolet rays including light having a wavelength of 150 to 800 nm and visible light can be used. Preferably, it is ultraviolet light containing light having a wavelength of 200 to 400 nm. When the radiation is polarized, it may be linearly polarized or partially polarized. When the radiation used is linearly polarized light or partially polarized light, the irradiation may be performed from a direction perpendicular to the substrate surface, may be performed from an oblique direction, or may be performed in combination thereof. In the case of unpolarized radiation, the irradiation direction is diagonal.

As the light source to be used, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, an excimer laser, or the like can be used. The irradiation amount of radiation is preferably 400 to 50,000 J / m ² , and more preferably 1,000 to 20,000 J / m ² . After light irradiation for imparting orientation ability, the surface of the substrate is washed with, for example, water, an organic solvent (for example, methanol, isopropyl alcohol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, etc.) or a mixture thereof. Or a process of heating the substrate may be performed. The heat treatment after light irradiation is preferably 130 ° C. or higher, more preferably 150 ° C. or higher, still more preferably 170 ° C. or higher.

(Step 3: Construction of liquid crystal cell)
A liquid crystal cell is manufactured by preparing two substrates on which the liquid crystal alignment film is formed as described above and arranging the liquid crystal between the two substrates arranged opposite to each other. In order to manufacture a liquid crystal cell, for example, two substrates are arranged to face each other with a gap so that the liquid crystal alignment films face each other, and the peripheral portions of the two substrates are bonded to each other using a sealing agent to form a surface of the substrate. Examples thereof include a method of injecting and filling a liquid crystal in a cell gap surrounded by a sealing agent to seal the injection hole, a method of using the ODF method, and the like. As the sealing agent, for example, an epoxy resin containing an aluminum oxide sphere as a curing agent and a spacer can be used. Examples of the liquid crystal include a nematic liquid crystal and a smectic liquid crystal, and among them, the nematic liquid crystal is preferable.

Subsequently, if necessary, a polarizing plate is attached to the outer surface of the liquid crystal cell to form a liquid crystal element. Examples of the polarizing plate include a polarizing plate in which a polarizing film called "H film" in which polyvinyl alcohol is stretch-oriented and iodine is absorbed is sandwiched between a cellulose acetate protective film, or a polarizing plate made of the H film itself.

The liquid crystal elements of the present disclosure can be effectively applied to various applications, for example, clocks, portable games, word processors, notebook computers, car navigation systems, camcorders, PDAs, digital cameras, mobile phones, smartphones, various monitors. , LCD TVs, information displays and other display devices, dimming films and the like. Further, a liquid crystal element formed by using the liquid crystal alignment agent of the present disclosure can also be used as a retardation film.

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

The compounds used in the following examples are as follows. In the following, for convenience, the "compound represented by the formula A" may be simply referred to as "compound A".

(Specific acid dianhydride)

(Other tetracarboxylic acid dianhydride)

(Diamine compound)

<Synthesis of compounds>
[Example 1-1]
Compound (4-1) was synthesized according to Scheme 1 below.

-Synthesis of compound (4-1-1) 24 g of compound (a), 0.01 g of N, N-dimethylformamide and 600 mL of dehydrated dichloromethane were placed in a 2 L flask and cooled to 0 ° C. under a nitrogen atmosphere. Subsequently, 60 g of thionyl chloride was slowly added dropwise using a syringe. After completion of the dropping, the reaction was carried out at 40 ° C. for 2 hours, and then the solvent was distilled off with an evaporator to obtain 25 g of the compound (4-1-1) (yield 90%).
-Synthesis of compound (4-1-2) 25 g of the obtained compound (4-1-1) was dissolved in 400 mL of tetrahydrofuran (THF) and cooled to 0 ° C. under a nitrogen atmosphere. 42 g of the aromatic amine compound (c) was placed in another 1 L flask, dissolved in 400 mL of THF, and the solution was slowly added dropwise to the flask of compound (4-1-1) using a cannula over 1 hour. After the dropping, the temperature was raised to room temperature, and the reaction was further carried out for 2 hours. After the reaction, 1 L of saturated aqueous sodium hydrogen carbonate solution was added to transfer the reaction solution to a separating funnel, and 1 L of ethyl acetate was further added to perform liquid separation extraction. After washing the organic layer with saturated brine, the solvent was distilled off with an evaporator until the content reached 50 g, and the resulting solid was collected by filtration to obtain 30 g of compound (4-1-2) (yield). Rate 53%).
-Synthesis of compound (4-1-3) 30 g of compound (4-1-2) was placed in a 2 L flask, and 400 mL of THF and 100 mL of water were added and dissolved. The temperature of the solution was lowered to 0 ° C. by ice cooling, 5 g of sodium hydroxide was added, and the mixture was reacted at 0 ° C. for 3 hours. After the reaction, 500 mL of a 10% aqueous sodium hydroxide solution was added and the mixture was transferred to a separatory funnel, and 500 mL of ethyl acetate was added to carry out a liquid separation operation. 1 L of THF was added to the aqueous layer, and 1 L of 15% dilute sulfuric acid was slowly added while cooling with ice. Separation extraction is performed using THF, the organic layer is washed, and after filtration, the solvent is distilled off with an evaporator, the mixture is distilled off until the content reaches 100 g, and the resulting solid is recovered by filtration, and the compound (4) is collected. 1-3) was obtained in an amount of 15 g (yield 54%).
-Synthesis of compound (4-1) 15 g of compound (4-1-3) and 11 g of acetic anhydride were added to a 1 L flask equipped with a reflux tube, and the reaction solution was slowly heated to 65 ° C. and reacted for 24 hours. I let you. After the reaction, the container was cooled to room temperature, and the solid generated during the reaction was recovered by filtration to obtain 12 g of compound (4-1) (yield 88%).

[Example 1-2]
Compound (4-2) was synthesized according to Scheme 2 below.

6 g of compound (4-1) was placed in a 1 L flask and dissolved in 500 mL of THF. After the solution was ice-bathed to 0 ° C., 1.4 g of sodium hydride was slowly added under a nitrogen atmosphere. The mixture was stirred for 1 hour while maintaining the reaction temperature at 0 ° C., and then 12 g of di-tert-butyl dicarbonate was added. The temperature was raised to room temperature, and the mixture was further stirred for 1 hour, and then 300 mL of saturated sodium hydrogen carbonate was added to stop the reaction. The liquid was transferred to a separatory funnel, and the liquid was separated and extracted using 500 mL of ethyl acetate. The organic layer was washed with saturated brine, the solvent was evaporated with an evaporator, and then recrystallized from ethyl acetate to give 7 g of compound (4-2) (yield 87%).

The compounds (4-3) and (4-4) were also synthesized by a method according to the compound (4-1) by changing the compound used as a raw material.
[Example 1-3]
Compound (4-3) was synthesized according to Scheme 3 below.

21 g of compound (4-1-1) was dissolved in 400 mL of THF and cooled to 0 ° C. under a nitrogen atmosphere. 34 g of the aliphatic amine compound (g) was placed in another 1 L flask, dissolved in 400 mL of THF, and the solution was slowly added dropwise to the flask of the compound (4-1-1) using a cannula over 1 hour. After the dropping, the temperature was raised to room temperature, and the reaction was further carried out for 2 hours. After the reaction, 1 L of saturated aqueous sodium hydrogen carbonate solution was added to transfer the reaction solution to a separating funnel, and 1 L of ethyl acetate was further added to perform liquid separation extraction. After washing the organic layer with saturated brine, the solvent was distilled off with an evaporator until the content reached 50 g, and the resulting solid was collected by filtration to obtain 25 g of compound (4-3-1) (yield). Rate 53%). Subsequently, 20 g of compound (4-3-1) was placed in a 2 L flask, and the same method as in which compound (4-1) was obtained from compound (4-1-2) in Example 1-1 was used. 3 g of compound (4-3) was obtained (yield 18%).

[Example 1-4]
Using 17 g of compound (f) as a raw material, 2 g of compound (4-4) was obtained by the same method as that of compound (4-1) (yield 43%).

For compounds (4-15) and (4-16), first, the compound used as a raw material was changed to synthesize a precursor by a method similar to compound (4-1), and then the obtained precursor was used. On the other hand, it was synthesized by introducing a protecting group by a method according to compound (4-2).
[Example 1-5]
Compound (4-15) was synthesized according to Scheme 4 below.

90 g of compound (i) was placed in a 2 L flask, and 55 g of compound (j) was obtained in the same manner as in Example 1-1 for obtaining compound (4-1-1) from compound (a) (yield). Rate 50%). Using 50 g of the obtained compound (j), 10 g of the compound (4-12) was obtained in the same manner as for obtaining the compound (4-3) from the compound (4-1-1) (yield 9%). ). Subsequently, 5 g of compound (4-12) was taken, and 4 g of compound (4-15) was obtained in the same manner as for obtaining compound (4-2) from compound (4-1) (yield 60%). ..

[Example 1-6]
Compound (4-16) was synthesized according to Scheme 5 below.

-Synthesis of compound (4-16-1) 10 g of palladium carbon, 200 g of ammonium formate, and 600 mL of a mixed solvent of water / methanol = 1/10 were placed in a 2 L flask, and the mixture was slowly stirred at room temperature. Then, 45 g of the compound (m) and 170 g of the compound (c) were dissolved in 700 mL of the same mixed solvent, the palladium catalyst was added dropwise to the stirred flask, and the mixture was stirred at room temperature for 3 hours. After the reaction, the solution was filtered through Celite and the solvent was distilled off using an evaporator. Further, 800 mL of dichloromethane and 300 mL of saturated brine were added to the concentrated mixture, and liquid separation extraction was performed. The organic layer was separated and the solvent was distilled off using an evaporator to obtain 120 g of compound (4-16-1) (yield 62%).
-Synthesis of compound (4-16-2) 110 g of compound (4-16-1) was placed in a 2 L flask, and the same method as in obtaining compound (4-1-3) in Example 1-1 was used. 63 g of compound (4-16-2) was obtained (yield 65%).
-Synthesis of compound (4-7) 58 g of compound (4-16-2) was placed in a 2 L flask, and compound (4-1) was obtained from compound (4-1-3) in Example 1-1. In the same manner as above, 32 g of compound (4-7) was obtained (yield 60%).
-Synthesis of compound (4-16) Finally, 27 g of compound (4-7) was taken in a 1 L flask, and compound (4-2) was obtained from compound (4-1) in Example 1-2. 4 g of compound (4-16) was obtained in the same manner (yield 10%).

<Synthesis of polymer>
[Example 2-1]
80 parts of compound (t-5) and 20 parts of compound (4-3) as tetracarboxylic dianhydride, and 100 parts of compound (d-8) as diamine, N-methyl-2-pyrrolidone ( It was dissolved in NMP) and reacted at 60 ° C. for 4 hours to obtain a solution containing 20% by mass of polyamic acid (referred to as “polymer (A-1)”).
[Examples 2-2 to 2-7, Synthesis Examples 1-1 to 1-4, and Comparative Synthesis Examples 1-1 to 1-4]
Polyamic acids were synthesized in the same manner as in Example 2-1 above, except that the types and amounts of tetracarboxylic dianhydrides and diamines used were changed as shown in Tables 1 and 2 below. In Tables 1 and 2, the values in parentheses for tetracarboxylic dianhydride and diamine indicate the ratio [molar part] of each compound to 100 mol parts in total of the tetracarboxylic acid derivative used for polymer synthesis. Represent. "-" Indicates that the corresponding compound was not used.

[Example 3-1]
1. 1. Preparation of liquid crystal alignment agent As the polymer component, the solution containing the polymer (A-1) obtained in Example 2-1 and the polymer (B-1) obtained in Synthesis Example 1-1 are contained. The solutions to be mixed are mixed so that the mass ratio of the polymer (solid content) is polymer (A-1): polymer (B-1) = 30: 70, and further NMP, 1,3-dimethyl-2. -Imidazolidinone (DMI), γ-butyrolactone (FGBL) and butyl cellosolve (BC) were added and stirred well, and the solvent composition was NMP: DMI: FGBL: BC = 40: 20: 20: 20 (mass ratio). A solution having a solid content concentration of 3.5% by mass was prepared. A liquid crystal alignment agent (S-1) was prepared by filtering this solution using a filter having a pore size of 0.20 μm.

2. Manufacture of rubbing FFS type liquid crystal display element The FFS type liquid crystal display element 10 shown in FIG. 1 was manufactured. First, a glass substrate 11a having an electrode pair on one side in which a bottom electrode 15 having no pattern, a silicon nitride film as an insulating layer 14, and a top electrode 13 patterned in a comb-teeth shape are formed in this order, and an electrode. The liquid crystal alignment agent (S-1) prepared in the above (1) is applied to each of the surface of the glass substrate 11a having a transparent electrode and one surface of the opposing glass substrate 11b, respectively, in pairs with the opposing glass substrate 11b not provided with the above. , Applied using a spinner. Next, after pre-baking on a hot plate at 80 ° C. for 1 minute, the inside of the oven is heated (post-baked) at 230 ° C. for 15 minutes in a nitrogen-substituted oven to form a coating film having an average film thickness of 0.1 μm. did. A schematic plan view of the top electrode 13 used here is shown in FIG. In this embodiment, the line width d1 of the electrodes is 4 μm, and the distance d2 between the electrodes is 6 μm. As the top electrode 13, four types of driving electrodes, electrode A, electrode B, electrode C, and electrode D, were used. FIG. 3 shows the configuration of the drive electrode used. In this case, the bottom electrode 15 acts as a common electrode that acts on all of the four drive electrodes, and each of the regions of the four drive electrodes becomes a pixel region.
Next, each surface of the coating film formed on the glass substrates 11a and 11b was subjected to a rubbing treatment with cotton to obtain a liquid crystal alignment film 12. The rubbing direction with respect to the coating film was set to be orthogonal to the arrow in FIG. 2 (b). Next, after applying a sealant to the outer edge of the surface of one of the pair of substrates having the liquid crystal alignment film 12, the rubbing directions of the substrates 11a and 11b are antiparallel to each other. The sealant was cured by adhering it to the substrate via a spacer having a diameter of 3.5 μm. Next, a negative liquid crystal "MLC-6608 (manufactured by Merck & Co., Inc.)" was injected between the pair of substrates from the liquid crystal injection port to form the liquid crystal layer 16. Further, polarizing plates (not shown) were attached to both outer surfaces of the substrates 11a and 11b so that the polarization directions of the two polarizing plates were orthogonal to each other to fabricate the liquid crystal display element 10.

3. 3. Evaluation of reliability with respect to light (BL reliability) For the FFS type liquid crystal display element manufactured above, a voltage of 1 V was applied at 23 ° C. for an application time of 60 microseconds and a span of 167 milliseconds, and then 167 after the application was released. The voltage holding rate [%] after milliseconds was measured, and the value was taken as the initial VHR. Next, the liquid crystal display element after the initial VHR measurement was allowed to stand in an oven at 80 ° C. under irradiation with an LED lamp for 200 hours, and then allowed to stand at room temperature to be naturally cooled to room temperature. The voltage retention rate of the liquid crystal display element after light irradiation was measured again by the same method as described above, and this value was defined as VHR after light stress. The amount of decrease in voltage retention due to light irradiation ΔVHR was obtained from the following mathematical formula (1), and BL reliability was evaluated.
ΔVHR = initial VHR-VHR after photostress ... (1)
In the liquid crystal display element manufactured in Example 3-1 because the electrode and the rubbing direction are orthogonal to each other, rubbing is less likely to be applied at the stepped portion of the electrode as compared with the positive type liquid crystal cell, and the reliability of the liquid crystal display element is lowered. It tends to be easy to do. BL reliability is "good A (◎)" when ΔVHR is 5% or less, "good B (○)" when it is larger than 5% and 10% or less, and 15% or less larger than 10%. If it was, it was judged as "OK (Δ)", and if it was larger than 15%, it was judged as "Defective (×)". As a result, in the liquid crystal display element of this example, ΔVHR = 5%, and the BL reliability was evaluated as “good A (⊚)”. As the voltage holding ratio measuring device, VHR-1 manufactured by Toyo Technica Co., Ltd. was used.

4. Evaluation of film adhesion The liquid crystal alignment agent (S-1) prepared in (1) above was applied onto a glass substrate using a spinner, prebaked on a hot plate at 80 ° C. for 1 minute, and then the inside of the oven was cooled. A coating film having an average film thickness of 0.08 μm was formed by heating (post-baking) in a nitrogen-substituted oven at 200 ° C. for 1 hour. By repeating the same operation as this, two glass substrates on which a coating film was formed were produced. An ODF sealant (S-WB42 manufactured by Sekisui Chemical Co., Ltd.) is applied on the coating film of one glass substrate on which the coating film is formed so that the diameter is 5 mm, and the coating film of the other glass substrate and the ODF seal are applied. The agents were bonded so that they would come into contact with each other. ^{Then, after irradiating with light of 30,000 J / m 2} (365 nm conversion) using a metal halide lamp, it was heated in an oven at 120 ° C. for 1 hour. Then, the adhesion of the film to the substrate was evaluated by measuring the adhesion force using a tensile compression tester (model number: SDWS-0201-100SL) manufactured by Imada Seisakusho. The rating is a case adhesion was at 200 N / cm ² or more "good A (◎)", a case was 175 N / cm ² or more 200 N / cm less than ² "good B (○)", 150 N / cm ^{When it was 2} or more and less than 175 N / cm ^2, it was evaluated as “OK (Δ)”, and ^{when it was less than 150 N / cm 2} , it was evaluated as “Defective (×)”. As a result, in this example, the adhesion was 221 N / cm ² , and the adhesion was evaluated as “good A (⊚)”.

[Example 3-2 and Comparative Examples 1 and 3]
Liquid crystal alignment agents were prepared at the same solid content concentration as in Example 3-1 above, except that the type and amount of the polymer used and the type and amount of the solvent were changed as shown in Table 3 below. Further, a liquid crystal display element was manufactured in the same manner as in Example 3-1 using each of the prepared liquid crystal alignment agents, and various evaluations were carried out in the same manner as in Example 3-1. The evaluation results are shown in Table 3 below.

[Example 3-3]
1. 1. Preparation of liquid crystal alignment agent The liquid crystal alignment agent (S-) has the same solid content concentration as in Example 3-1 above, except that the type and amount of the polymer used and the type and amount of the solvent are changed as shown in Table 3 below. 3) was prepared.
2. Manufacture of Optically Horizontally Aligned Liquid Crystal Display Element The liquid crystal aligning agent prepared above is placed on a glass substrate having a metal electrode made of chrome patterned in a comb-like shape on one side and a facing glass substrate having no electrode. (S-3) was applied using a spinner so that the film thickness was 0.1 μm. Then, after drying on a hot plate at 80 ° C. for 1 minute, the surface of the coating film was ^{irradiated with polarized ultraviolet rays of 10,000 J / m 2} including a bright line of 254 nm from the normal direction of the substrate using an Hg-Xe lamp. Then, it was dried in a clean oven at 200 ° C. for 1 hour. Next, on the pair of substrates subjected to the light irradiation treatment, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm was screen-printed and applied, leaving a liquid crystal injection port on the edge of the surface on which the liquid crystal alignment film was formed. The substrates were overlapped and pressure-bonded so that the projection directions of the polarizing axes on the substrate surface at the time of light irradiation were antiparallel, and the adhesive was thermoset at 150 ° C. for 1 hour. Next, a negative liquid crystal (MLC-7026 manufactured by Merck Co., Ltd.) was filled between the pair of substrates from the liquid crystal injection port, and then the liquid crystal injection port was sealed with an epoxy adhesive. Further, in order to eliminate the flow orientation at the time of liquid crystal injection, this was heated at 150 ° C. and then slowly cooled to room temperature. Then, a polarizing plate was attached to both outer surfaces of the substrate to produce a liquid crystal display element.

3. 3. Evaluation of BL reliability and film adhesion The above 2. Using the optical horizontal alignment type liquid crystal display element manufactured in 1. When the BL reliability was evaluated in the same manner as in the above, ΔVHR = 14% in this example, which was an evaluation of “good B (◯)”. Further, using the liquid crystal alignment agent (S-3), 4. When the adhesion of the film was evaluated in the same manner as in the above, it was 190 N / cm ² in this example, and the adhesion was evaluated as "good B (◯)".

[Comparative Example 2]
A liquid crystal alignment agent (R-2) was prepared at the same solid content concentration as in Example 3-1 above, except that the type and amount of the polymer used and the type and amount of the solvent were changed as shown in Table 3 below. .. Further, using the prepared liquid crystal alignment agent (R-2), an optical horizontal alignment type liquid crystal display element is manufactured in the same manner as in Example 3-3, and BL reliability is obtained in the same manner as in Example 3-1. And the adhesion of the film was evaluated. The evaluation results are shown in Table 3 below.

In Table 3, the numerical values in parentheses in the polymer column indicate the ratio (parts by mass) of each compound to 100 parts by mass of the total amount of the polymers used for preparing the liquid crystal aligning agent. The numerical value in the solvent composition column indicates the ratio of each compound used to 100 parts by mass of the total amount of the solvent used for preparing the liquid crystal alignment agent. The abbreviations for solvents have the following meanings (the same applies to Table 4 below).
NMP: N-methyl-2-pyrrolidone DMI: 1,3-dimethyl-2-imidazolidinone FGBL: γ-butyrolactone BC: Butyl cellosolve DEDG: Diethylene glycol diethyl ether DPM: Dipropylene glycol monomethyl ether

[Example 3-4]
1. 1. Preparation of liquid crystal alignment agent The liquid crystal alignment agent (S-) has the same solid content concentration as in Example 3-1 above, except that the type and amount of the polymer used and the type and amount of the solvent are changed as shown in Table 4 below. 4) was prepared.
2. Manufacture of vertically oriented liquid crystal display element A liquid crystal aligning agent (S-4) prepared above is applied on a pair of glass substrates having a transparent electrode made of an ITO film on one side with a spinner, and placed on a hot plate at 80 ° C. After pre-baking for 1 minute, it was post-baked on a hot plate at 230 ° C. for 10 minutes to form a coating film having a film thickness of about 0.08 μm. Subsequently, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm was applied to the outer edge of the surface of either substrate having the liquid crystal alignment film, and then the two substrates were placed facing each other through a gap. The outer edges were crimped together to cure the adhesive. Next, a nematic liquid crystal (MLC-6608, manufactured by Merck Co., Ltd.) was filled between the pair of substrates from the liquid crystal injection port, and then the liquid crystal injection port was sealed with an acrylic photocurable adhesive.
3. 3. Evaluation of BL reliability Above 2. Using the vertically oriented liquid crystal display element manufactured in 1. BL reliability was evaluated by ΔVHR in the same manner as above. In the vertically oriented liquid crystal display element, BL reliability is "good A (⊚)" when ΔVHR is less than 1%, and "good B (◯)" when it is 1% or more and less than 1.5%. ) ”, A case of 1.5% or more and less than 3% was evaluated as“ OK (Δ) ”, and a case of 3% or more was evaluated as“ Defective (×) ”. As a result, in the liquid crystal display element of this example, ΔVHR = 1.3%, and the BL reliability was evaluated as “good B (◯)”.
4. Evaluation of Film Adhesion Using a liquid crystal alignment agent (S-4), Example 3-1-4. When the adhesion of the film was evaluated in the same manner as in the above, it was 202 N / cm ² in this example, and the adhesion was evaluated as "good A (⊚)".

[Examples 3-5 to 3-7 and Comparative Example 4]
Liquid crystal alignment agents were prepared at the same solid content concentration as in Example 3-1 above, except that the type and amount of the polymer used and the type and composition of the solvent were as shown in Table 4 below. Further, using each of the prepared liquid crystal aligning agents, a vertically oriented liquid crystal display element was manufactured in the same manner as in Example 3-4, and various evaluations were performed in the same manner as in Example 3-1. The evaluation of BL reliability was performed according to Example 3-4. The evaluation results are shown in Table 4 below.

As can be seen from the above results, the liquid crystal display device manufactured by using the liquid crystal alignment agent containing the polymer [A] has improved BL reliability and adhesion of the film to the substrate in a well-balanced manner.

10 ... Liquid crystal display element, 11a, 11b ... Glass substrate, 12 ... Liquid crystal alignment film, 13 ... Top electrode, 14 ... Insulation layer, 15 ... Bottom electrode, 16 ... Liquid crystal layer

Claims (8)

A liquid crystal alignment agent containing a polymer [A] having at least one selected from the group consisting of a partial structure represented by the following formula (1) and a partial structure represented by the following formula (2).

(In the formulas (1) and (2) , Q ¹ is a tetravalent organic group represented by the following formula (3), Q ² is a divalent organic group, and R ¹ and R ² are. , Each independently is a hydrogen atom or a monovalent organic group.)

(In the formula (3), A ¹ and A ² are groups in which ^three hydrogen atoms are independently removed from the aromatic ring group or the cyclohexane ring, respectively, and R 3 is a divalent group having 1 to 18 carbon atoms. an organic group, R ⁴ and R ⁵ are each independently a hydrogen atom or a monovalent organic group, by bonding R ⁴ and R ^5, the nitrogen atom to which R ⁴ is attached, R ⁵ is attached together with the nitrogen atom and R ³ may be ring is formed. "*" indicates a bond that binds to the carbonyl group.) Claim 1 in which the R ³ is ^{bonded to at least one of the two nitrogen atoms adjacent to the R 3} with a carbonyl group, a methylene group, an alicyclic group, an aromatic ring group or a heterocyclic group. The liquid crystal alignment agent according to. The polymer component is derived from a diamine compound having at least one selected from the group consisting of a nitrogen-containing heterocycle, a secondary amino group and a tertiary amino group in the same molecule as or different from the polymer [A]. The liquid crystal alignment agent according to claim 1 or 2, which comprises a structural unit. The polymer [A] further contains a structural unit derived from an alicyclic tetracarboxylic acid derivative having no partial structure represented by the above formula (3), according to any one of claims 1 to 3. The liquid crystal alignment agent described. The liquid crystal alignment agent according to any one of claims 1 to 4, wherein the polymer [A] is a polymer exhibiting photo-orientation. The liquid crystal alignment agent according to claim 5, wherein the polymer [A] is a polymer that exhibits photoalignment by heating to 150 ° C. or higher after irradiation with polarized ultraviolet rays. A liquid crystal alignment film formed by using the liquid crystal alignment agent according to any one of claims 1 to 6. A liquid crystal element comprising the liquid crystal alignment film according to claim 7.

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