JP2023131110A - Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal element - Google Patents

Abstract

To provide a liquid crystal alignment agent that has good liquid crystal alignment properties, has good DC storage characteristics and DC relaxation characteristics, and reduces the generation of an afterimage.SOLUTION: A liquid crystal alignment agent contains a polymer (P). The polymer (P) includes one or more of a partial structure (U2-1), a partial structure (U2-2), and a partial structure (U2-3), and a partial structure (U1) in the same molecule, and the molecule including the partial structure (U1) includes two or more of the partial structure (U2-1), partial structure (U2-2), and partial structure (U2-3) in the same molecule or in different molecules. The partial structure (U1) has a partial structure obtained by removing two hydrogen atoms from a structure represented by the formula (Y-1). The partial structure (U2-1) includes, in a main chain, a partial structure in which a chain-like hydrocarbon structure and *1-NR1-CO- and the like are adjacent to each other. The partial structure (U2-2) has a carboxylic acid group or a sulfonic acid group. The partial structure (U2-3) has nitrogen-containing heterocycles.SELECTED DRAWING: None

Description

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

Liquid crystal elements are used in a wide range of applications, from relatively large display devices such as liquid crystal televisions and information displays to small display devices such as smartphones. The performance of a liquid crystal element is determined by various characteristics such as the orientation of the liquid crystal, the size of the pretilt angle, and the voltage holding rate. In order to improve the performance of liquid crystal elements, improvements have been made to liquid crystal alignment films for aligning liquid crystals in a certain direction.

When a charge is accumulated in a liquid crystal cell due to the application of a voltage to a liquid crystal element, it may be visually recognized by an observer as an afterimage (DC afterimage), and the display quality of the liquid crystal element may deteriorate. Therefore, one of the characteristics required of the liquid crystal alignment film is that there is little charge accumulation.

Therefore, various techniques have been proposed in the past for suppressing the accumulation of charges in liquid crystal cells and improving the display quality of liquid crystal elements (see, for example, Patent Document 1 and Patent Document 2). Patent Document 1 describes that a polyamic acid obtained by reacting a diamine compound containing a nitrogen-containing diamine such as N4,N4'-bis(4-aminophenyl)-benzidine with a tetracarboxylic dianhydride is used as a liquid crystal aligning agent. It is disclosed that the amount of accumulated charge can be reduced by incorporating the compound into the compound. Patent Document 2 discloses that a liquid crystal alignment film in which accumulated charges are quickly relaxed is obtained by incorporating a polymer obtained from a diamine having a structure in which a carbazole structure and a benzene ring are bonded via an amino group into a liquid crystal alignment agent. has been done.

Japanese Patent Application Publication No. 2008-107811 International Publication No. 2018/110354

With the demand for higher quality liquid crystal elements, there is a need to develop liquid crystal elements that are less likely to cause afterimages. In order to suppress the occurrence of afterimages and improve the quality of liquid crystal elements, it is necessary to make it difficult for charge to accumulate in the liquid crystal cell even when a voltage is applied (hereinafter also referred to as "DC accumulation characteristic"), and to prevent the accumulated charge from accumulating in the liquid crystal cell. It is required to be relaxed quickly (hereinafter also referred to as "DC relaxation characteristics"). Furthermore, in order to obtain a high-quality liquid crystal element, it is desirable that both the DC accumulation property and the DC relaxation property be good while maintaining good liquid crystal orientation, which is one of the basic properties of a liquid crystal element.

The present invention was made in view of the above-mentioned problems, and provides a liquid crystal aligning agent that can obtain a liquid crystal element that has good liquid crystal alignment properties, good DC accumulation characteristics and DC relaxation characteristics, and is less likely to cause afterimages. One purpose is to

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

（式（１）中、Ｘ^１は４価の有機基である。Ｙ^１は、下記式（Ｙ－１）で表される構造から２個の水素原子を取り除いてなる部分構造を有する２価の有機基である。）

（式（Ｙ－１）中、Ａ^１及びＡ^２は、それぞれ独立して、芳香族炭化水素環を有する１価の基であり、芳香族炭化水素環が式（Ｙ－１）中の窒素原子に結合しているか、又は、Ａ^１とＡ^２とが互いに合わせられて、Ａ^１及びＡ^２が結合する窒素原子と共に構成される窒素含有縮合複素環構造を表す。Ａ^３は水素原子又は１価の有機基である。ただし、Ａ^１及びＡ^２が、互いに合わせられてＡ^１及びＡ^２が結合する窒素原子と共に構成される窒素含有縮合複素環構造を表す場合、窒素含有縮合複素環構造は２個以上の芳香族炭化水素環を有し、窒素含有縮合複素環構造が有する２個の芳香族炭化水素環が式（Ｙ－１）中の窒素原子を共有して結合した縮合環構造を有するか、又は、Ａ^３が芳香族炭化水素環を有し、Ａ^３が有する芳香族炭化水素環が式（Ｙ－１）中の窒素原子に結合している。）

（式（２）、式（３）及び式（４）中、Ｘ^２、Ｘ^３及びＸ^４は、それぞれ独立して４価の有機基である。Ｙ^２は、鎖状炭化水素構造と「＊^１－ＮＲ^１－ＣＯ－」、「＊^１－ＣＯ－ＮＲ^１－」、「＊^１－ＮＲ^１－ＣＯ－ＮＲ^２－」又は「＊^１－ＣＯ－ＮＲ^１－ＮＲ^２－ＣＯ－」とが隣接した部分構造を主鎖に含む２価の基である。Ｒ^１及びＲ^２は、それぞれ独立して水素原子又は１価の有機基である。「＊^１」は鎖状炭化水素構造との結合手を表す。Ｙ^３は、カルボン酸基又はスルホン酸基を有する２価の有機基である。Ｙ^４は、含窒素複素環、「－Ｒ^３－ＮＲ^４－Ｒ^５－」及び「－Ｒ^６－ＮＲ^７Ｒ^８」よりなる群から選択される少なくとも１種の部分構造を有する２価の有機基（ただし、Ｙ^２に該当する基を除く。）である。Ｒ^３、Ｒ^５及びＲ^６は、それぞれ独立して２価の脂肪族炭化水素基である。Ｒ^４、Ｒ^７及びＲ^８は、それぞれ独立して、水素原子、熱脱離性基又は１価の脂肪族炭化水素基である。） <1> Contains a polymer (P), the polymer (P) has a partial structure represented by the following formula (1), a partial structure represented by the following formula (2), and the following formula (3). A molecule that contains any one or more of the partial structure represented by the following formula (4) and the partial structure represented by the following formula (4) in the same molecule, and also contains the partial structure represented by the following formula (1) , any two or more of the partial structure represented by the following formula (2), the partial structure represented by the following formula (3), and the partial structure represented by the following formula (4) in the same molecule or in different molecules Liquid crystal aligning agent contained within.

(In formula (1), X ¹ is a tetravalent organic group. Y ¹ is a divalent organic group having a partial structure obtained by removing two hydrogen atoms from the structure represented by the following formula (Y-1). )

(In formula (Y-1), A ¹ and A ² are each independently a monovalent group having an aromatic hydrocarbon ring, and the aromatic hydrocarbon ring is the nitrogen in formula (Y-1). A ¹ and A ² are combined with each other to represent a nitrogen-containing fused heterocyclic structure formed with the nitrogen atom to which A ¹ and A ² are bonded. A ³ is a hydrogen atom or A monovalent organic group.However, when A ¹ and A ² are combined with each other to represent a nitrogen-containing fused heterocyclic structure constituted with the nitrogen atom to which A ¹ and A ² are bonded, the nitrogen-containing fused heterocycle is a monovalent organic group. The structure has two or more aromatic hydrocarbon rings, and the two aromatic hydrocarbon rings of the nitrogen-containing fused heterocyclic structure are bonded together by sharing the nitrogen atom in formula (Y-1). structure, or ^A3 has an aromatic hydrocarbon ring, and the aromatic hydrocarbon ring of ^A3 is bonded to the nitrogen atom in formula (Y-1).)

(In formula (2), formula (3) and formula (4), X ² , X ³ and X ⁴ are each independently a tetravalent organic group. Y ² has a chain hydrocarbon structure and " * ¹ -NR ¹ -CO-", "* ¹ -CO-NR ¹ -", "* ¹ -NR ¹ -CO-NR ² -" or "* ¹ -CO-NR ¹ -NR ² -CO-" is a divalent group containing adjacent partial structures in the main chain. R ¹ and R ² are each independently a hydrogen atom or a monovalent organic group. "* ¹ " is a chain hydrocarbon structure represents a bond with Y ³ is a divalent organic group having a carboxylic acid group or a sulfonic acid group. Y ⁴ is a nitrogen-containing heterocycle, "-R ³ -NR ⁴ -R ⁵ -" and A divalent organic group having at least one partial structure selected from the group consisting of "-R ⁶ -NR ⁷ R ⁸ " (excluding the group corresponding to Y ² ). R ³ , R ⁵ and R ⁶ are each independently a divalent aliphatic hydrocarbon group. R ⁴ , R ⁷ and R ⁸ are each independently a hydrogen atom, a thermally releasable group, or a monovalent aliphatic group. It is a hydrocarbon group.)

（式（５）及び（６）中、Ｘ^５及びＸ^６は、それぞれ独立して、脂環式構造を有する４価の基である。Ｙ^５及びＹ^６は、それぞれ独立して、窒素原子に熱脱離性基が結合した部分構造を含む２価の有機基である。） <2> The polymer (P) has a partial structure represented by the above formula (1), a partial structure represented by the above formula (2), and a partial structure represented by the above formula (3) in the same molecule. The liquid crystal aligning agent according to <1> above, which contains any two or more of the partial structure and the partial structure represented by the above formula (4).
<3> The liquid crystal aligning agent according to <1> or <2>, wherein the polymer (P) contains a structural unit derived from aromatic tetracarboxylic dianhydride.
<4> The liquid crystal aligning agent according to any one of <1> to <3> above, further comprising a polymer (Q) different from the polymer (P).
<5> The polymer (Q) contains a polymer containing at least one selected from the group consisting of a partial structure represented by the following formula (5) and a partial structure represented by the following formula (6). The liquid crystal aligning agent as described in said <4>.

(In formulas (5) and (6), X ⁵ and X ⁶ are each independently a tetravalent group having an alicyclic structure. Y ⁵ and Y ⁶ are each independently a nitrogen atom (It is a divalent organic group containing a partial structure in which a thermally releasable group is bonded to.)

<6> The liquid crystal aligning agent according to <5> above, wherein the alicyclic structure is a substituted or unsubstituted cyclobutane ring structure.
<7> Further contains a compound having three or more in one molecule at least one selected from the group consisting of oxiranyl group, oxetanyl group, hydroxy group, mercapto group, amino group, and polymerizable carbon-carbon double bond group. The liquid crystal aligning agent according to any one of the above <1> to <6>.
<8> The liquid crystal aligning agent according to any one of <1> to <7> above, further containing a compound having a trialkoxysilyl group.
<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.

According to the liquid crystal aligning agent of the present invention, it is possible to obtain a liquid crystal element that maintains good liquid crystal alignment, has good DC accumulation characteristics and DC relaxation characteristics, and is less likely to cause afterimages due to charge accumulation. .

《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 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.

The liquid crystal aligning agent of the present disclosure contains a polymer (P). The polymer (P) is at least one selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide, and is an aggregate of polymers containing a partial structure (U1) in the molecule. In addition, the molecules constituting the polymer (P) include any one or more of the partial structure (U2-1), the partial structure (U2-2), and the partial structure (U2-3), and the partial structure (U1). and a molecule containing partial structure (U1) in the same molecule, any two or more of partial structure (U2-1), partial structure (U2-2), and partial structure (U2-3) are the same. Contained within a molecule or within a different molecule. For each substructure, substructure (U1) has a specific nitrogen-containing structure that imparts hole transport properties to the polymer. The partial structure (U2-1) has a structure that imparts hydrogen bonding properties to the main chain of the polymer. The partial structure (U2-2) has an acidic functional group, and the partial structure (U2-3) has a nitrogen-containing heterocycle.

Here, the molecule containing the partial structure (U1) has "any two or more of the partial structure (U2-1), the partial structure (U2-2), and the partial structure (U2-3)" in the same molecule or in different Contained in the molecule means three partial structures, partial structure (U2-1), partial structure (U2-2), and partial structure (U2-3), in the polymer (P), which is an aggregate of polymers. It means to include any two or all three of them. Specifically, when the polymer (P) contains any two of the three partial structures: partial structure (U2-1), partial structure (U2-2), and partial structure (U2-3), the polymer Does the coalescence (P) (i.e., the aggregate of polymers containing the partial structure (U1)) include the partial structure (U2-1) and the partial structure (U2-2) in the same molecule or in different molecules? , includes a partial structure (U2-1) and a partial structure (U2-3), or includes a partial structure (U2-2) and a partial structure (U2-2). In addition, when the polymer (P) contains all three of the partial structure (U2-1), the partial structure (U2-2), and the partial structure (U2-3), the polymer (P) is contained in the same molecule or Different molecules include a partial structure (U2-1), a partial structure (U2-2), and a partial structure (U2-3). Specific embodiments of the polymer (P) include the following <1> to <4>.

<1> A molecule containing the partial structure (U1) contains the partial structure (U2-1) and the partial structure (U2-2) in the same molecule or in different molecules.
<2> A molecule containing the partial structure (U1) contains the partial structure (U2-1) and the partial structure (U2-3) in the same molecule or in different molecules.
<3> The molecule containing the partial structure (U1) contains the partial structure (U2-2) and the partial structure (U2-3) in the same molecule or in different molecules.
<4> A polymer in which the molecule containing the partial structure (U1) contains the partial structure (U2-1), the partial structure (U2-2), and the partial structure (U2-3) in the same molecule or in different molecules.

Note that each of the polymers <1> to <4> above may contain only one type of partial structure (U1), or may contain two or more types. Each of the above polymers <1>, <2> and <4> may contain only one type of partial structure (U2-1), or may contain two or more types. Each of the polymers <1>, <3> and <4> above may contain only one type of partial structure (U2-2), or may contain two or more types. Each of the polymers <2> to <4> above may contain only one type of partial structure (U2-3), or may contain two or more types.

Specific examples of the case where the polymer (P) contains any two or more of the partial structure (U2-1), the partial structure (U2-2), and the partial structure (U2-3) in different molecules include: For example, in the case of <1> above, the polymer (P) has the partial structure (U1) and the partial structure (U2-1) in the same molecule, and the polymer (P) has the partial structure (U1) and the partial structure (U2-2) in the same molecule. ) in the same molecule. In the case of <4> above, the polymer (P) is a polymer having the partial structure (U1) and the partial structure (U2-1) in the same molecule, and the partial structure (U1) and the partial structure (U2-2). An embodiment including a polymer having in the same molecule a polymer having partial structure (U1) and partial structure (U2-3) in the same molecule; partial structure (U1), partial structure (U2-1) and Embodiment including a polymer having the partial structure (U2-2) in the same molecule and a polymer having the partial structure (U1) and the partial structure (U2-3) in the same molecule; partial structure (U1) and the moiety An embodiment including a polymer having the structure (U2-1) in the same molecule, and a polymer having the partial structure (U1), the partial structure (U2-2), and the partial structure (U2-3) in the same molecule; etc.

The polymer (P) has the same molecular structure in that it is possible to obtain a liquid crystal element with less afterimage due to good DC accumulation characteristics and DC relaxation characteristics while minimizing the number of components constituting the liquid crystal aligning agent. It is preferable that the structure includes at least two of the partial structure (U2-1), the partial structure (U2-2), and the partial structure (U2-3), and the partial structure (U1).

The details of the partial structure (U1), partial structure (U2-1), partial structure (U2-2), and partial structure (U2-3) will be described below.

（式（１）中、Ｘ^１は４価の有機基である。Ｙ^１は、下記式（Ｙ－１）で表される構造から２個の水素原子を取り除いてなる部分構造を有する２価の有機基である。）

（式（Ｙ－１）中、Ａ^１及びＡ^２は、それぞれ独立して、芳香族炭化水素環を有する１価の基であり、芳香族炭化水素環が式（Ｙ－１）中の窒素原子に結合しているか、又は、Ａ^１とＡ^２とが互いに合わせられて、Ａ^１及びＡ^２が結合する窒素原子と共に構成される窒素含有縮合複素環構造を表す。Ａ^３は水素原子又は１価の有機基である。ただし、Ａ^１及びＡ^２が、互いに合わせられてＡ^１及びＡ^２が結合する窒素原子と共に構成される窒素含有縮合複素環構造を表す場合、窒素含有縮合複素環構造は２個以上の芳香族炭化水素環を有し、窒素含有縮合複素環構造が有する２個の芳香族炭化水素環が式（Ｙ－１）中の窒素原子を共有して結合した縮合環構造を有するか、又は、Ａ^３が芳香族炭化水素環を有し、Ａ^３が有する芳香族炭化水素環が式（Ｙ－１）中の窒素原子に結合している。） <Partial structure (U1)>
The partial structure (U1) is a structural unit represented by the following formula (1).

(In formula (1), X ¹ is a tetravalent organic group. Y ¹ is a divalent organic group having a partial structure obtained by removing two hydrogen atoms from the structure represented by the following formula (Y-1). )

(In formula (Y-1), A ¹ and A ² are each independently a monovalent group having an aromatic hydrocarbon ring, and the aromatic hydrocarbon ring is the nitrogen in formula (Y-1). A ¹ and A ² are combined with each other to represent a nitrogen-containing fused heterocyclic structure formed with the nitrogen atom to which A ¹ and A ² are bonded. A ³ is a hydrogen atom or A monovalent organic group.However, when A ¹ and A ² are combined with each other to represent a nitrogen-containing fused heterocyclic structure constituted with the nitrogen atom to which A ¹ and A ² are bonded, the nitrogen-containing fused heterocycle is a monovalent organic group. The structure has two or more aromatic hydrocarbon rings, and the two aromatic hydrocarbon rings of the nitrogen-containing fused heterocyclic structure are bonded together by sharing the nitrogen atom in formula (Y-1). structure, or ^A3 has an aromatic hydrocarbon ring, and the aromatic hydrocarbon ring of ^A3 is bonded to the nitrogen atom in formula (Y-1).)

In the above formula (1), Y ¹ is a diamine having a partial structure obtained by removing two hydrogen atoms from the structure represented by the above formula (Y-1) (hereinafter also referred to as "specific diamine (D1)"). ) is a group derived from A ¹ and A ² in the above formula (Y-1) each have an aromatic hydrocarbon ring, and the aromatic hydrocarbon ring that A ¹ and A ² have is attached to the nitrogen atom in the formula (Y-1). When bonded through a single bond, the aromatic hydrocarbon rings in A ¹ and A ² may be monocyclic or polycyclic. Examples of the aromatic hydrocarbon ring in A ¹ and A ² include a benzene ring, a naphthalene ring, an anthracene ring, and the like. Among these, the aromatic hydrocarbon ring in A ¹ and A ² is preferably a benzene ring or a naphthalene ring, and more preferably a benzene ring. The aromatic hydrocarbon rings in A ¹ and A ² may have a substituent. Examples of the substituent include a methyl group, an ethyl group, and a halogen atom.

When A ¹ and A ² are combined with each other to represent a nitrogen-containing fused heterocyclic structure constituted with the nitrogen atom to which A ¹ and A ² are bonded, the nitrogen-containing fused heterocyclic structure includes an indoline structure, an indole structure, , 1,2,3,4-tetrahydroquinoline structure, 1,2-dihydroquinoline structure, 1,2-dihydroisoquinoline structure, carbazole structure, phenoxazine structure, phenothiazine structure, and the like. These heterocyclic structures may have a substituent on the ring portion. Examples of the substituent include a methyl group, an ethyl group, and a halogen atom. The nitrogen-containing fused heterocyclic structure formed by combining A ¹ and A ² with each other includes an indoline structure, an indole structure, a 1,2,3,4-tetrahydroquinoline structure, and a 1,2-dihydroquinoline structure. , 1,2-dihydroisoquinoline structure, and carbazole structure are preferred.

When A ³ is a monovalent organic group, examples of the monovalent organic group include a monovalent hydrocarbon group having 1 to 10 carbon atoms, a thermally releasable group, and the like. Examples of the monovalent hydrocarbon group include an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, and an aryl group having 6 to 10 carbon atoms.

A thermally releasable group is a substituent that is removed by heat applied to a liquid crystal aligning agent during formation of a liquid crystal aligning film and replaced with a hydrogen atom. Examples of the thermally releasable group include carbamate-based protecting groups, amide-based protecting groups, imide-based protecting groups, and sulfonamide-based protecting groups. Among these, carbamate-based protecting groups are preferred in view of their high thermal removability. 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 A ¹ and A ² represent the nitrogen-containing fused heterocyclic structure, the nitrogen-containing fused heterocyclic structure represented by A ¹ and A ² has two or more aromatic hydrocarbon rings, and the nitrogen-containing fused heterocyclic structure has two or more aromatic hydrocarbon rings. The heterocyclic structure has a fused ring structure (hereinafter also referred to as "fused ring structure Cp") in which two aromatic hydrocarbon rings are bonded together by covalently bonding the nitrogen atom in formula (Y-1), or , A ³ has an aromatic hydrocarbon ring, and the aromatic hydrocarbon ring is bonded to the nitrogen atom in formula (Y-1). Examples of the condensed ring structure Cp include a carbazole structure, a phenoxazine structure, a phenothiazine structure, and the like, with a carbazole structure being preferred.

Y ¹ in the above formula (1) may have a partial structure obtained by removing two hydrogen atoms from the structure represented by the above formula (Y-1). The hydrogen atom removed from the structure represented by the above formula (Y-1) may be a hydrogen atom possessed by any of A ¹ , A ² and A ³ . Specifically, Y ¹ in the above formula (1) may be a divalent group having a partial structure in which one hydrogen atom is removed from A ¹ and A ² , or A ¹ and A ³ It may also be a divalent group having a partial structure in which hydrogen atoms are removed one by one.

Y ¹ preferably has a partial structure derived from the above formula (Y-1) in its main chain from the viewpoint of sufficiently reducing afterimages generated in a liquid crystal element. The number of partial structures derived from the above formula (Y-1) in Y ¹ may be one or two or more.

（式中、「＊」は結合手を表す。） Specific examples of the divalent organic group represented by Y ¹ include groups represented by the following formula.

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

In the polymer (P), the content of structural units derived from the specific diamine (D1) is preferably 3 mol% or more based on the total amount of structural units derived from diamines possessed by the polymer (P). , more preferably 5 mol% or more. Further, the content ratio of structural units derived from the specific diamine (D1) is preferably 90 mol% or less, and 80 mol% or less, based on the total amount of structural units derived from diamines that the polymer (P) has. It is more preferable that By setting the content of the structural unit derived from the specific diamine (D1) within the above range, the DC afterimage characteristics (particularly the DC relaxation characteristics) of the liquid crystal element can be improved, and the occurrence of DC afterimages can be sufficiently reduced.

In addition, when the polymer (P) contains two or more types of polymers with different monomer compositions, the proportion of structural units derived from the specific diamine (D1) is determined by the proportion of structural units derived from the diamine constituting the polymer (P). The ratio of structural units to the total amount. For example, when the liquid crystal aligning agent of the present disclosure includes a first polymer and a second polymer having different monomer compositions as the polymer (P), the proportion of structural units derived from the specific diamine (D1) is the specific diamine (D1) constituting the first polymer relative to the total amount of structural units derived from all diamines constituting the first polymer and structural units derived from all diamines constituting the second polymer. It represents the ratio of the total amount of the derived structural units and the structural units derived from the specific diamine (D1) constituting the second polymer (the same applies to the following structural units).

（式（２）中、Ｘ^２は、４価の有機基である。Ｙ^２は、鎖状炭化水素構造と「＊^１－ＮＲ^１－ＣＯ－」、「＊^１－ＣＯ－ＮＲ^１－」、「＊^１－ＮＲ^１－ＣＯ－ＮＲ^２－」又は「＊^１－ＣＯ－ＮＲ^１－ＮＲ^２－ＣＯ－」とが隣接した部分構造を主鎖に含む２価の基である。Ｒ^１及びＲ^２は、それぞれ独立して水素原子又は１価の有機基である。「＊^１」は鎖状炭化水素構造との結合手を表す。） <Partial structure (U2-1)>
The partial structure (U2-1) is a structural unit represented by the following formula (2).

(In formula (2), X ² is a tetravalent organic group. Y ² has a chain hydrocarbon structure and "* ¹ -NR ¹ -CO-", "* ¹ -CO-NR ¹ -" , "* ¹ -NR ¹ -CO-NR ² -" or "* ¹ -CO-NR ¹ -NR ² -CO-" is a divalent group containing adjacent partial structures in the main chain. R ¹ and R ² are each independently a hydrogen atom or a monovalent organic group. "* ¹ " represents a bond with a chain hydrocarbon structure.)

In the above formula (2), Y ² has a chain hydrocarbon structure and "* ¹ -NR ¹ -CO-", "* ¹ -CO-NR ¹ -", "* ¹ -NR ¹ -CO-NR ² -" or "* ¹ -CO-NR ¹ -NR ² -CO-" is a group derived from a diamine containing an adjacent partial structure in the main chain (hereinafter also referred to as "specific diamine (D2-1)"). be. The chain hydrocarbon structure that Y ² has may be saturated or unsaturated. The chain hydrocarbon structure possessed by Y ² may be linear or branched, but is preferably a linear saturated or unsaturated hydrocarbon group, specifically a linear alkanediyl group. and alkenediyl groups. Adjacent to "* ¹ -NR ¹ -CO-", "* ¹ -CO-NR ¹ -", "-NR ¹ -CO-NR ² -" or "-CO-NR ¹ -NR ² -CO-" The number of carbon atoms per chain hydrocarbon structure is preferably 1 to 10, more preferably 2 to 8, and even more preferably 2 to 5.

In addition, Y ² has a chain hydrocarbon structure and "* ¹ -NR ¹ -CO-", "* ¹ -CO-NR ¹ -", "* ¹ -NR ¹ -CO-NR ² -" or "* ¹ -CO-NR ¹ -NR ² -CO-" as long as the main chain has an adjacent partial structure, it may further have a cyclic structure. The cyclic structure that Y ² may have is not particularly limited. Specific examples of the cyclic structure that Y ² may have include alicyclic groups such as cycloalkanediyl groups and cycloalkenediyl groups; aromatic hydrocarbon groups such as phenylene groups; piperidinediyl groups and piperazinediyl groups. , pyridinediyl group, pyridazinediyl group, and other heterocyclic groups.

"* ¹ -NR ¹ -CO-", "* ¹ -CO-NR ¹ -", "* ¹ -NR ¹ -CO-NR ² -" or "* ¹ -CO-NR ¹ -NR ² -CO-""In the group represented by ", when R ¹ and R ² are monovalent organic groups, specific examples of R ¹ and R ² include a monovalent hydrocarbon group having 1 to 10 carbon atoms and a thermally desorbed group. Examples include sexual groups. When R ¹ and R ² are monovalent hydrocarbon groups, the monovalent hydrocarbon group is preferably an alkyl group having 1 to 3 carbon atoms or a phenyl group, more preferably an alkyl group having 1 to 3 carbon atoms. . Specific examples of the heat-eliminating group include the same groups as those exemplified as specific examples when A ³ is a heat-eliminating group in the explanation of A ³ in formula (1) above. 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.

Among the above, R ¹ and R ² are preferably a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a thermally releasable group, and more preferably a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a tert-butoxycarbonyl group. Preferably, a hydrogen atom is more preferable.

"* ¹ -NR ¹ -CO-", "* ¹ -CO-NR ¹ -", "* ¹ -NR ¹ -CO-NR ² -" or "* ¹ -CO-NR ¹ -NR ² -CO-" ”, a chain hydrocarbon structure is bonded to the “* ¹ ” side. On the side opposite to "* ¹ ", a chain hydrocarbon structure may be adjacent, and a structure different from the chain hydrocarbon structure (specifically, a cyclic hydrocarbon group or a heterocyclic group) may be adjacent. You may do so. Further, the adjacent group on the opposite side to "* ¹ " may have a substituent such as a halogen atom or a hydroxyl group.

A preferred example of Y ² is a divalent group represented by the following formula (y2-1).
*-Ar ¹ -R ³ -Z ¹ -(R ⁴ -Z ² ) _n -R ⁵ -Ar ² -*...(y2-1)
(In formula (y2-1), Ar ¹ and Ar ² are each independently a divalent aromatic ring group or alicyclic group. Z ¹ and Z ² are each independently "* ¹ - NR ¹ -CO-", "* ¹ -CO-NR ¹ -", "* ¹ -NR ¹ -CO-NR ² -", or "* ¹ -CO-NR ¹ -NR ² -CO-". "* ¹ " represents a bond with a chain hydrocarbon structure. R ³ and R ⁵ are each independently a single bond or a divalent chain hydrocarbon group. R ⁴ is a divalent organic group.However, when R ³ is a single bond, R ⁴ bonded to Z ¹ is a divalent chain hydrocarbon group. When R ⁵ is a single bond, it is bonded to Z ² adjacent to Ar ² . R ⁴ is a divalent chain hydrocarbon group. n is an integer from 0 to 2. "*" represents a bond.)

In the above formula (y2-1), the divalent aromatic ring group represented by Ar ¹ or Ar ² is a group obtained by removing two hydrogen atoms from the ring portion of an aromatic ring. Examples of the aromatic ring include a benzene ring, a naphthalene ring, a pyridine ring, and a pyrimidine ring. The divalent alicyclic group represented by Ar ¹ or Ar ² is a group obtained by removing two hydrogen atoms from the ring portion of an aliphatic ring such as a cyclohexane ring. The divalent aromatic ring group or alicyclic group represented by Ar ¹ or Ar ² may have a substituent on the ring portion. Examples of the substituent include a methylene group, an ethylene group, a halogen atom, and the like. Among them, Ar ¹ and Ar ² are preferably phenylene groups from the viewpoint of forming a liquid crystal alignment film exhibiting good liquid crystal alignment.

When R ³ and R ⁵ are divalent chain hydrocarbon groups, examples of R ³ and R ⁵ include linear alkanediyl groups and alkenediyl groups. The divalent chain hydrocarbon group represented by R ³ and R ⁵ is preferably a linear alkanediyl group, more preferably a linear alkanediyl group having 1 to 5 carbon atoms.

The divalent organic group represented by R ⁴ includes a divalent hydrocarbon group and a heterocyclic group. Examples of the divalent hydrocarbon group include a chain hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. Specific examples of the divalent organic group represented by ^R4 include alkanediyl group, alkenediyl group, cycloalkanediyl group, cycloalkenediyl group, phenylene group, piperidinediyl group, piperazinediyl group, pyridinediyl group, and pyridazine. Examples include diyl group.

（式中、「Ｂｏｃ」はｔｅｒｔ－ブトキシカルボニル基を表す。「＊」は結合手を表す。） Specific examples of the divalent organic group represented by Y ² include groups represented by the following formula.

(In the formula, "Boc" represents a tert-butoxycarbonyl group. "*" represents a bond.)

When the polymer (P) contains a structural unit derived from the specific diamine (D2-1), the content thereof is 5 mol% or more based on the total amount of the structural unit derived from the diamine possessed by the polymer (P). It is preferable that it is, and it is more preferable that it is 10 mol% or more. Further, the content ratio of structural units derived from the specific diamine (D2-1) is preferably 90 mol% or less, and 80 mol% or less, based on the total amount of structural units derived from diamines possessed by the polymer (P). % or less is more preferable. By setting the content ratio of the structural unit derived from the specific diamine (D2-1) within the above range, the DC afterimage characteristics (especially DC accumulation characteristics) of the liquid crystal element can be improved, and the occurrence of DC afterimages can be sufficiently reduced. can.

（式（３）中、Ｘ^３は、４価の有機基である。Ｙ^３は、カルボン酸基又はスルホン酸基を有する２価の有機基である。） <Partial structure (U2-2)>
The partial structure (U2-2) is a structural unit represented by the following formula (3).

(In formula (3), X ³ is a tetravalent organic group. ^{Y 3} is a divalent organic group having a carboxylic acid group or a sulfonic acid group.)

In the above formula (3), Y ³ is a group derived from a diamine having a carboxylic acid group or a sulfonic acid group (hereinafter also referred to as "specific diamine (D2-2)"). The carboxylic acid group or sulfonic acid group in Y ³ may be bonded to a chain structure or may be bonded to a ring structure. In Y ³ , a carboxylic acid group or a sulfonic acid group 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 carboxylic acid group or a sulfonic acid 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 3 carbon atoms. A divalent group in which any methylene group in the alkanediyl group of 4 is replaced with -O-, -CO-, -COO-, -NR ⁶ - or -CO-NR ⁶ - (R ⁶ is a hydrogen atom or a monovalent organic group). The number of carboxylic acid groups or sulfonic acid groups that Y 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 group represented by Y ³ include groups represented by the following formula.

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

When the polymer (P) contains a structural unit derived from the specific diamine (D2-2), the content thereof is 5 mol% or more based on the total amount of the structural unit derived from the diamine possessed by the polymer (P). It is preferable that it is, and it is more preferable that it is 10 mol% or more. Further, the content ratio of structural units derived from the specific diamine (D2-2) is preferably 90 mol% or less, and 60 mol% or less, based on the total amount of structural units derived from diamines possessed by the polymer (P). % or less is more preferable. By setting the content of the structural unit derived from the specific diamine (D2-2) within the above range, the DC afterimage characteristics (especially DC accumulation characteristics) of the liquid crystal element can be improved, and the occurrence of DC afterimages can be sufficiently reduced. can.

（式（４）中、Ｘ^４は、４価の有機基である。Ｙ^４は、含窒素複素環、「－Ｒ^３－ＮＲ^４－Ｒ^５－」及び「－Ｒ^６－ＮＲ^７Ｒ^８」よりなる群から選択される少なくとも１種の部分構造を有する２価の有機基（ただし、Ｙ^２に該当する基を除く。）である。Ｒ^３、Ｒ^５及びＲ^６は、それぞれ独立して２価の脂肪族炭化水素基である。Ｒ^４、Ｒ^７及びＲ^８は、それぞれ独立して、水素原子、熱脱離性基又は１価の脂肪族炭化水素基である。） <Partial structure (U2-3)>
The partial structure (U2-3) is a structural unit represented by the following formula (4).

(In formula (4), X ⁴ is a tetravalent organic group. Y ⁴ is a nitrogen-containing heterocycle, "-R ³ -NR ⁴ -R ⁵ -" and "-R ⁶ -NR ⁷ R ⁸ ” ^is a divalent organic group having ^{at least} one partial structure selected from ^the group consisting of is a divalent aliphatic hydrocarbon group. R ⁴ , R ⁷ and R ⁸ are each independently a hydrogen atom, a thermally releasable group, or a monovalent aliphatic hydrocarbon group.)

In the above formula (4), Y ⁴ is at least one member selected from the group consisting of a nitrogen-containing heterocycle, "-R ³ -NR ⁴ -R ⁵ -" and "-R ⁶ -NR ⁷ R ⁸ ". It is a group derived from a diamine (hereinafter also referred to as "specific diamine (D2-3)") having a partial structure (hereinafter also referred to as "nitrogen-containing structure Ny"). When Y ⁴ has a nitrogen-containing heterocycle, the nitrogen-containing heterocycle may be an aromatic heterocycle or a non-aromatic heterocycle. Further, the nitrogen-containing heterocycle in Y ⁴ may be a monocyclic ring or a condensed ring. Specific examples of nitrogen-containing heterocycles in ^Y4 include nitrogen-containing aromatic heterocycles such as pyrrole ring, imidazole ring, pyrazole ring, triazole ring, pyridine ring, pyrimidine ring, pyridazine ring, quinoline ring, and benzimidazole. ring, a carbazole ring, a pyrazine ring, and a heterocycle having a substituent (eg, methyl group, ethyl group, etc.) on these rings. Examples of nitrogen-containing non-aromatic heterocycles include piperidine rings, piperazine rings, morpholine rings, hexamethyleneimine rings, and heterocycles in which substituents (for example, methyl groups, ethyl groups, etc.) are introduced into these rings. Can be mentioned. Among these, the nitrogen-containing heterocycle in Y ⁴ has a structure having at least one member selected from the group consisting of a pyridine ring, a pyrimidine ring, a pyrazine ring, a piperidine ring, a piperazine ring, a quinoline ring, a benzimidazole ring, and a carbazole ring. is preferred.

Examples of the divalent aliphatic hydrocarbon group represented by R ³ , R ⁵ or R ⁶ include an alkanediyl group, an alkenediyl group, a cycloalkanediyl group, and the like. The divalent aliphatic hydrocarbon group represented by R ³ , R ⁵ or R ⁶ is preferably an alkanediyl group.
The monovalent aliphatic hydrocarbon group represented by R ⁴ , R ⁷ or R ⁸ is preferably an alkyl group, more preferably an alkyl group having 1 to 3 carbon atoms.
Specific ^examples of the thermally releasable group represented by R ⁴ , R ⁷ or R ⁸ are as follows when A ³ in the above formula (1) is a thermally releasable group. Groups similar to the exemplified groups can be mentioned. Among these, a tert-butoxycarbonyl group (Boc group) is particularly preferred.

Y ⁴ may have the nitrogen-containing structure Ny in the main chain of the polymer, in the side chain, or in both the main chain and the side chain. From the viewpoint of obtaining a liquid crystal element with sufficiently reduced afterimage, it is preferable that ^Y4 has a nitrogen-containing structure Ny in the side chain of the polymer. The number of nitrogen-containing structures Ny that Y ⁴ has is not particularly limited, and is, for example, 1 to 4, preferably 1 to 3.

Y ⁴ may be a group consisting only of a nitrogen-containing heterocycle, or may have a ring structure or a chain structure different from the nitrogen-containing heterocycle together with the nitrogen-containing heterocycle. Moreover, these ring structures and chain structures may be present in the main chain of the polymer or in the side chains. As a chain structure, an alkanediyl group having 1 to 10 carbon atoms, any methylene group in the alkanediyl group is replaced with -O-, -CO-, -COO-, -NR ⁷ - or -CO-NR ⁷ - (R ⁷ is a hydrogen atom or a monovalent organic group), and the like. Ring structures different from the nitrogen-containing heterocycle include aromatic hydrocarbon rings (benzene ring, naphthalene ring, etc.).

However, Y ⁴ is a group different from Y ² in the above formula (2). That is, the specific diamine (D2-3) is a different compound from the specific diamine (D2-1), and Y ⁴ has a chain hydrocarbon structure and "* ¹ -NR ¹ -CO-", "* ¹ -CO -NR ¹ -", "* ¹ -NR ¹ -CO-NR ² -" or "* ¹ -CO-NR ¹ -NR ² -CO-" is a divalent compound that does not have an adjacent partial structure in its main chain. It is the basis. Note that the specific diamine (D1), the specific diamine (D2-1), the specific diamine (D2-2), and the specific diamine (D2-3) that constitute the polymer (P) are mutually different compounds.

（式中、「＊」は結合手を表す。） Specific examples of the divalent organic group represented by Y ⁴ include groups having a nitrogen-containing structure Ny in the main chain and represented by the following formula.

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

（式中、「＊」は結合手を表す。） Further, as a specific example of the divalent organic group represented by Y ⁴ , a group having a nitrogen-containing structure Ny in a side chain and represented by the following formula can be mentioned.

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

When the polymer (P) contains a structural unit derived from the specific diamine (D2-3), the content thereof is 3 mol% or more based on the total amount of the structural unit derived from the diamine possessed by the polymer (P). It is preferable that it is, and it is more preferable that it is 5 mol% or more. Further, the content ratio of structural units derived from the specific diamine (D2-3) is preferably 90 mol% or less, and 60 mol% or less, based on the total amount of structural units derived from diamines possessed by the polymer (P). % or less is more preferable. By setting the content of the structural unit derived from the specific diamine (D2-3) within the above range, the DC afterimage characteristics (especially DC accumulation characteristics) of the liquid crystal element can be improved, and the occurrence of DC afterimages can be sufficiently reduced. can.

In the polymer (P), the total content of structural units derived from the specific diamine (D2-1), structural units derived from the specific diamine (D2-2), and structural units derived from the specific diamine (D2-3) is preferably 10 mol% or more, more preferably 20 mol% or more, based on the total amount of structural units derived from diamines that the polymer (P) has. In addition, the total content ratio of the structural unit derived from the specific diamine (D2-1), the structural unit derived from the specific diamine (D2-2), and the structural unit derived from the specific diamine (D2-3) is It is preferably 97 mol% or less, more preferably 95 mol% or less, based on the total amount of structural units derived from diamines contained in P).

The tetravalent group represented by X ¹ in the above formula (1), X ² in the above formula (2), X ³ in the above formula (3), and X 4 in the above formula ( ⁴ ) is a tetravalent group represented by It is a structural unit derived from carboxylic acid anhydride. Examples of the tetracarboxylic anhydride include aliphatic tetracarboxylic dianhydride and aromatic tetracarboxylic dianhydride. Examples of aliphatic tetracarboxylic dianhydrides include chain tetracarboxylic dianhydrides and alicyclic tetracarboxylic dianhydrides.

Examples of the chain tetracarboxylic dianhydride include 1,2,3,4-butanetetracarboxylic dianhydride, ethylenediaminetetraacetic dianhydride, and the like. 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, etc. 3,5,6-tricarboxy-2-carboxymethylnorbornane-2:3,5:6-dianhydride is mentioned. 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.

The tetracarboxylic dianhydride constituting each partial structure (U1), (U2-1) to (U2-3) had a high effect of improving the DC relaxation characteristics of the liquid crystal element, and the occurrence of afterimages was sufficiently reduced. It is preferable that a structural unit derived from an aromatic tetracarboxylic dianhydride is included in that a liquid crystal element can be obtained. In the polymer (P), the proportion of structural units derived from aromatic tetracarboxylic dianhydride is 10 to the total amount of structural units derived from tetracarboxylic dianhydride constituting the polymer (P). It is preferably at least mol %, more preferably at least 20 mol %, even more preferably at least 30 mol %.

[Other diamines]
When synthesizing the polymer (P), specific diamine (D1), specific diamine (D2-1), specific diamine (D2-2), and diamines different from specific diamine (D2-3) (hereinafter referred to as "other diamines") (also referred to as "diamine") may be used in combination. Other diamine compounds 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（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を、
ジアミノオルガノシロキサンとして、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。 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, 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'-(phenylene diisopropylidene) bisaniline, and other main chain diamines;
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.)
Side chain type diamines such as compounds represented by
Examples of the diaminoorganosiloxane include 1,3-bis(3-aminopropyl)-tetramethyldisiloxane and the like.

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).

When synthesizing the polymer (P), the proportion of other diamines used is preferably 75 mol% or less, and preferably 65 mol% or less, based on the total amount of diamines used in the synthesis of the polymer (P). It is more preferable.

[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 can be prepared by, for example, [I] a method of reacting polyamic acid (P) with an esterifying agent, [II] a tetracarboxylic acid diester and diamine, or [III] tetracarboxylic acid diester dihalide and 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 99%, more preferably 30 to 90%. 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 20% by mass or more with respect to 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 40% by mass or more, and still more preferably 60% by mass or more.

<Other ingredients>
In addition to the polymer (P), the liquid crystal aligning agent may contain a component different from the polymer (P) (hereinafter also referred to as "other components") as necessary.

・Polymer (Q)
The liquid crystal aligning agent of the present disclosure may further contain a polymer (Q) different from the polymer (P). By blending the polymer (Q) with the polymer (P), it is possible to form a liquid crystal alignment film that has good liquid crystal alignment and provides a highly reliable liquid crystal element.

The main skeleton of the polymer (Q) is not particularly limited. Examples of the polymer (Q) include polyamic acid, polyamic acid ester, polyimide, polyorganosiloxane, polyester, polyenamine, polyurea, polyamide, polyamideimide, polybenzoxazole precursor, polybenzoxazole, cellulose derivative, polyacetal, and Examples include polymers (eg, (meth)acrylic polymers, styrene polymers, maleimide polymers, styrene-maleimide copolymers), and the like. Among these, the polymer (Q) is preferably at least one selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide. In addition, when the polymer (Q) is at least one selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide, the polymer (Q) is a polymer that does not have the partial structure (U1).

（式（５）及び（６）中、Ｘ^５及びＸ^６は、それぞれ独立して、脂環式構造を有する４価の基である。Ｙ^５及びＹ^６は、それぞれ独立して、窒素原子に熱脱離性基が結合した部分構造を含む２価の有機基である。） The liquid crystal aligning agent of the present disclosure has at least one kind selected from the group consisting of a partial structure represented by the following formula (5) and a partial structure represented by the following formula (6) as a polymer (Q). It is preferable to contain a polymer (hereinafter also referred to as "polymer (Q-1)"). By incorporating the polymer (Q-1) together with the polymer (P) in the liquid crystal aligning agent, it is possible to promote layer separation of the polymer components, which is preferable in that the liquid crystal alignment can be improved.

(In formulas (5) and (6), X ⁵ and X ⁶ are each independently a tetravalent group having an alicyclic structure. Y ⁵ and Y ⁶ are each independently a nitrogen atom (It is a divalent organic group containing a partial structure in which a thermally releasable group is bonded to.)

In formulas (5) and (6) above, the tetravalent groups represented by X ⁵ and X ⁶ are tetracarboxylic dianhydrides having an alicyclic structure (i.e., alicyclic tetracarboxylic dianhydrides It is a group derived from Specific examples of the alicyclic tetracarboxylic dianhydride include the same compounds as those exemplified as the alicyclic tetracarboxylic dianhydride constituting the polymer (P). The alicyclic structure of X ⁵ and X ⁶ is preferably a substituted or unsubstituted cyclobutane ring structure.

In the substituted cyclobutane ring structure, substituents include an alkyl group having 1 to 6 carbon atoms, a halogenated alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, and a halogenated group having 1 to 6 carbon atoms. Examples include an alkoxy group and a halogen atom. Among these, the substituents that the cyclobutane ring structure has are alkyl groups having 1 to 3 carbon atoms, halogenated alkyl groups having 1 to 3 carbon atoms, alkoxy groups having 1 to 3 carbon atoms, and halogenated groups having 1 to 3 carbon atoms. An alkoxy group or a halogen atom is preferred, an alkyl group having 1 to 3 carbon atoms, a fluoroalkyl group having 1 to 3 carbon atoms, or a fluorine atom is more preferred, and a methyl group is particularly preferred.

Specific examples of the tetracarboxylic dianhydride constituting the tetravalent group represented by X ⁵ and X ⁶ include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1-methyl-1, 2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2,3,4- Cyclobutanetetracarboxylic dianhydride, 1,2,3-trimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4 -Cyclobutanetetracarboxylic dianhydride, 1-ethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-diethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride , 1-ethyl-3-methyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethoxy-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3 -diethoxy-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1-trifluoromethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-di(trifluoromethyl )-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-di(trifluoromethoxy)-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3 -Tri(trifluoromethyl)-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetra(trifluoromethyl)-1,2,3,4-cyclobutanetetracarboxylic acid Examples include acid dianhydrides. Among these, at least one selected from the group consisting of 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride. Seeds are preferred.

The divalent organic group represented by Y ⁵ and Y ⁶ is a group derived from a diamine having a partial structure in which a thermally releasable group is bonded to a nitrogen atom (hereinafter also referred to as "partial structure (Np)"). be. Specific examples of the thermally releasable group that the partial structure Np has include the same groups as those exemplified as specific examples when ^A3 is a thermally releasable group in the explanation of ^A3 in formula (1) above. can be mentioned. Among the thermally releasable groups possessed by the partial structure Np, a tert-butoxycarbonyl group is particularly preferable.

（式（Ｎｐ－１）及び式（Ｎｐ－２）中、Ｒ^１０は熱脱離性基である。Ｒ^１１は、水素原子、炭素数１～１０の１価の炭化水素基又は熱脱離性基である。「＊」は結合手を表す。「＊^２」は、主鎖を構成する原子との結合手を表す。） The polymer (Q-1) may have the partial structure Np in the main chain, in the side chain, or in both. Specific examples of the partial structure Np include a monovalent group represented by the following formula (Np-1) and a divalent group represented by the formula (Np-2).

(In formula (Np-1) and formula (Np-2), R ¹⁰ is a thermally releasable group. R ¹¹ is a hydrogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms, or a thermally releasable group. It is a sexual group. "*" represents a bond. "* ² " represents a bond with an atom constituting the main chain.)

Specific examples of diamines having a partial structure (Np) include compounds represented by the following formulas.

When the polymer (Q) is contained in the liquid crystal aligning agent, the content ratio of the polymer (Q) is based on 100 parts by mass of the total amount of the polymer (P) and the polymer (Q) contained in the liquid crystal aligning agent. The amount is preferably 5 parts by mass or more, more preferably 10 parts by mass or more. Moreover, the content ratio of the polymer (Q) is preferably 80 parts by mass or less, and 60 parts by mass with respect to 100 parts by mass of the total amount of the polymer (P) and the polymer (Q) contained in the liquid crystal aligning agent. The following is more preferable, and 40% by mass or less is even more preferable.

The content ratio of the polymer (Q-1) is preferably 5 parts by mass or more, and 10 parts by mass based on 100 parts by mass of the total amount of the polymer (P) and polymer (Q) contained in the liquid crystal aligning agent. The above is more preferable. Further, the content ratio of the polymer (Q-1) is preferably 80 parts by mass or less, and 60 parts by mass or less with respect to 100 parts by mass of the total amount of the polymer (P) and the polymer (Q) contained in the liquid crystal aligning agent. It is more preferably at most parts by mass, and even more preferably at most 40% by mass.

-Crosslinking agent The liquid crystal aligning agent of the present disclosure may contain a crosslinking agent for the purpose of improving the mechanical strength of the film. The crosslinking agent includes at least one crosslinking group selected from the group consisting of oxiranyl group, oxetanyl group, hydroxyl group, mercapto group, amino group, and polymerizable carbon-carbon double bond group, three in one molecule. Compounds having the above (hereinafter also referred to as "compound (Z)") can be preferably used. The number of crosslinkable groups possessed by the compound (Z) is preferably 3 to 10, more preferably 3 to 6, from the viewpoint of ensuring the toughness of the membrane while improving the mechanical strength of the membrane.

When compound (Z) is contained in a liquid crystal aligning agent, the content ratio of compound (Z) is the total amount of polymer components contained in the liquid crystal aligning agent (total amount of polymer (P) and polymer (Q)). ) It is preferably 0.5 part by mass or more, more preferably 1 part by mass or more, per 100 parts by mass. Moreover, the content ratio of the compound (Z) is preferably 15 parts by mass or less, more preferably 10 parts by mass or less, based on 100 parts by mass of the total amount of polymer components contained in the liquid crystal aligning agent.

- Adhesion aid The liquid crystal alignment agent of the present disclosure may contain an adhesion aid for the purpose of improving the adhesion of the liquid crystal alignment film. As the adhesion aid, a compound having a trialkoxysilyl group (hereinafter also referred to as "compound (Y)") can be preferably used. Compound (Y) is a compound having at least one reactive functional group selected from the group consisting of oxiranyl group, oxetanyl group, hydroxy group, mercapto group, amino group, and polymerizable carbon-carbon double bond group. It is preferable. As such a compound (Y), a known silane coupling agent having the above-mentioned reactive functional group can be used as appropriate.

When compound (Y) is contained in a liquid crystal aligning agent, the content ratio of compound (Y) is the total amount of polymer components contained in the liquid crystal aligning agent (the total amount of polymer (P) and polymer (Q)). ) It is preferably 0.1 part by mass or more, more preferably 0.3 part by mass or more, per 100 parts by mass. Moreover, the content ratio of the compound (Y) is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, based on 100 parts by mass of the total amount of polymer components contained in the liquid crystal aligning agent.

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

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, for example, antioxidants, metal chelate compounds, hardening accelerators, surfactants, fillers, dispersants, photosensitizers, and the like. 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 type (Polymer Sustained Alignment), etc. 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.

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-7); Compounds represented by the following formulas (TA-1) to (TA-7), respectively

[Diamine]
Compound (DA-1) to Compound (DA-6); Compounds represented by the following formulas (DA-1) to (DA-6), respectively

Compound (DB-1) to Compound (DB-6); Compounds represented by the following formulas (DB-1) to (DB-6), respectively

Compounds (DC-1), (DC-2); Compounds represented by the following formula (DC-1) or formula (DC-2)

Compound (DD-1) to compound (DD-4); Compounds represented by the following formulas (DD-1) to (DD-4), respectively

Compound (DE-1) to compound (DE-13); Compounds represented by the following formulas (DE-1) to (DE-13), respectively

[Additive]
Compounds (AD-1) to Compounds (AD-4); Compounds represented by the following formulas (AD-1) to (AD-4), respectively

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

<Synthesis and evaluation of polymer>
Polymers were synthesized in Synthesis Examples 1 to 52 below. In addition, in the following examples, the imidization rate of polyimide in the polymer solution was measured by the following method.
[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).)

[Synthesis example 1]
Diamine (relative to 100 moles of total diamine, 10 moles of diamine (DA-1), 40 moles of diamine (DB-2), 20 moles of diamine (DC-1), and 30 moles of diamine (DE-3) part) in NMP, 0.95 molar equivalent of tetracarboxylic dianhydride based on the total amount of diamine (acid dianhydride (TA-1) based on 100 molar parts of total tetracarboxylic dianhydride). 40 mol parts and 60 mol parts of acid dianhydride (TA-5) were added, and the reaction was carried out at room temperature for 6 hours to form a 15% by mass solution of polyamic acid (this will be referred to as polymer (PA-1)). Obtained.

[Synthesis Examples 2 to 32]
Polyamic acids (polymer (PA-2) to polymer (PA- 32)) were obtained.

[Synthesis Examples 33 to 38]
Polyamic acids (polymer (PA-32) to polymer (PA- 38)) were obtained.

[Synthesis example 39]
Diamine (50 mole parts of diamine (DE-11), 30 mole parts of diamine (DE-12), and 20 mole parts of diamine (DE-2) based on 100 mole parts of total diamine) was dissolved in NMP, and the total diamine 0.95 molar equivalent of tetracarboxylic dianhydride (TA-2) was added thereto, and the reaction was carried out at room temperature for 6 hours to obtain a solution of polyamic acid. To the resulting solution were added 1-methylpiperidine and acetic anhydride in an amount of 0.75 molar equivalent to the carboxy group of the polyamic acid 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 (this will be referred to as polymer (PI-1)). The imidization rate of polyimide (PI-1) was 78%.

[Synthesis example 40]
A polyimide (this is referred to as a polymer (PI-2)) was obtained in the same manner as Synthesis Example 39, except that the types and molar ratios of the tetracarboxylic dianhydride and diamine were changed as shown in Table 2 below. Ta.

[Synthesis Examples 41 to 51]
Polyamic acids (Polymer (PA-39) to Polymer (PA- 49)) were obtained.
[Synthesis example 52]
A 10% by mass solution of a polyimide polymer (PI-3) was obtained in the same manner as Synthesis Example 39 except that the molar ratio of the dehydrating agent was changed to 0.40 molar equivalent. The imidization rate of the polymer (PI-3) was 50%.

For acid dianhydrides, the values in Tables 1 to 3 indicate the usage ratio (mol%) of each compound relative to the total amount of acid dianhydride used in the synthesis (100 mol%), and for diamines, the ratio of each compound used in the synthesis is The usage ratio (mol%) of each compound with respect to the total amount (100mol%) of diamine used in is shown.

<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)), crosslinking agent (N, N, N', N 5 parts by mass of '-tetrakis(2-hydroxyethyl)adipamide (a compound represented by the above formula (AD-1))), and an adhesion aid (3-glycidyloxypropyltrimethoxysilane (a compound represented by the above formula (AD-4)); By diluting 1 part by mass of the compound represented by )) with NMP and BC, a solution with a solid content concentration of 4.0% by mass and a solvent composition ratio of NMP:BC = 70:30 (mass ratio) is prepared. 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 A liquid crystal injection hole is left on the outer periphery of one of the substrates prepared in (2) above on the surface having a liquid crystal alignment film, and an epoxy resin containing aluminum oxide spheres with a diameter of 3.5 μm is After applying the 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 alignment direction of each substrate is antiparallel, and the adhesive is heated at 150°C for 1 hour. hardened. 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 Regarding the liquid crystal display element manufactured in (4) 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) was examined using a microscope at a magnification of 50x. Observed. 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 long-term afterimage at room temperature (DC relaxation characteristics) The liquid crystal display element manufactured in (4) above was placed in an environment of 25° C. and 1 atm. After driving with an alternating current rectangular wave (AC) with a frequency of 30 Hz at a relative transmittance of 100% and setting the luminance difference between any two pixels to 0, DC driving is applied to only one pixel while AC driving under backlight illumination. (DC) 0.5V was applied for 30 minutes to accumulate charge. When the application of DC 0.5 V was terminated and the drive was returned to AC only with a relative transmittance of 50%, a luminance difference ΔL occurred between the two pixels due to the accumulated charge. The change over time of this luminance difference ΔL was observed, and the time from the end of the application of DC 0.5 V until the luminance difference ΔL became 36.8% or less of the initial value was defined as the afterimage erasing time. It should be noted that the shorter this time, the easier the afterimage caused by the accumulated charges disappears, and it can be said that the DC relaxation characteristics are better. The evaluation is "Excellent" if the afterimage removal time is less than 10 minutes, "Good" if it is 10 minutes or more and less than 20 minutes, "Acceptable" if it is 20 minutes or more and less than 30 minutes. If the time was longer than 1 minute, it was classified as "unacceptable". As a result, this example was evaluated as "good".

(6) Evaluation of high-temperature short-term afterimage (DC accumulation characteristics) The liquid crystal display element manufactured in (4) above was placed in an environment of 60° C. and 1 atm. After driving with an alternating current rectangular wave (AC) with a frequency of 30 Hz at a relative transmittance of 100% and setting the luminance difference between any two pixels to 0, DC driving is applied to only one pixel while AC driving under backlight illumination. (DC) 0.2V was applied for 30 minutes to accumulate charge. When the application of DC 0.2 V was terminated and the drive was returned to AC only with a relative transmittance of 50%, a brightness difference ΔL occurred between the two pixels due to the accumulated charge. Note that the smaller the luminance difference, the more difficult it is to accumulate charges, and the better the DC accumulation characteristics. If the value obtained by dividing this brightness difference ΔL by the average value of the brightness of two pixels is less than 1%, it is ``excellent'', and if it is 1% or more and less than 2%, it is ``good'', which is 2% or more and less than 3%. If it was 3% or more, it was considered "acceptable", and if it was 3% or more, it was "impossible". As a result, this example was evaluated as "fair".

[Examples 2 to 17, Examples 26 to 29]
In Example 1 above, a liquid crystal aligning agent was prepared in the same manner as in Example 1, except that the type and amount of the polymer component to be contained in the liquid crystal aligning agent were changed as shown in Table 4 below. While forming a liquid crystal alignment film, an FFS type liquid crystal display element was manufactured and various evaluations were performed. The evaluation results are shown in Table 4 below. The exposure amount of linearly polarized ultraviolet light was 200 mJ/cm 2 in Examples 2 to 4, Examples 10 to 11, Examples 13 to 17, Examples 26 and 28 to 29, and 200 mJ/cm ² in other examples. In this case, it was set to 500 mJ/cm ² .

[Comparative Examples 1 to 14]
In the above Example 1, a liquid crystal aligning agent was prepared in the same manner as in Example 1 except that the type and amount of the polymer component to be contained in the liquid crystal aligning agent were changed as shown in Table 5 below. While forming a liquid crystal alignment film, an FFS type liquid crystal display element was manufactured and various evaluations were performed. The evaluation results are shown in Table 5 below. The exposure amount of linearly polarized ultraviolet light was 200 mJ/cm ² in Comparative Examples 1 to 12, and 500 mJ/cm ² in Comparative Examples 13 and 14.

[Example 18: Rubbing alignment FFS type liquid crystal display element]
(1) Preparation of liquid crystal aligning agent Polymer components (solid content equivalent: 20 parts by mass of polymer (PI-2), 80 parts by mass of polymer (PA-1)), crosslinking agent (N, N, N', N 5 parts by mass of '-tetrakis(2-hydroxyethyl)adipamide (a compound represented by the above formula (AD-1))), and an adhesion aid (3-glycidyloxypropyltrimethoxysilane (a compound represented by the above formula (AD-4)); By diluting 1 part by mass of the compound represented by )) with NMP and BC, a solution with a solid content concentration of 4.0% by mass and a solvent composition ratio of NMP:BC = 70:30 (mass ratio) is prepared. Obtained. A liquid crystal aligning agent (AL-18) 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-18) 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 coating surface was rubbed 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. Ta. 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 FFS was produced in the same manner as in Example 1, except that the pair of substrates having liquid crystal alignment films produced by the rubbing method in (2) above were used as the substrates having liquid crystal alignment films. A type liquid crystal display device was manufactured.

(4) Evaluation of liquid crystal orientation The FFS type liquid crystal display element manufactured in (3) above was evaluated for liquid crystal orientation in the same manner as in Example 1. As a result, this example was evaluated as "good".

(5) Evaluation of long-term afterimage at room temperature (DC relaxation characteristics) The DC relaxation characteristics of the FFS 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".

(6) Evaluation of high temperature short-term afterimage (DC accumulation characteristics) The DC accumulation characteristics of the FFS 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 "fair".

[Examples 19 to 25]
In the above Example 18, a liquid crystal aligning agent was prepared in the same manner as in Example 18, except that the type and amount of the polymer component to be contained in the liquid crystal aligning agent were changed as shown in Table 4 below. Along with forming an alignment film, an FFS type liquid crystal display element was manufactured and various evaluations were performed. The evaluation results are shown in Table 4 below.

In Tables 4 and 5, the mass ratio of each polymer in the liquid crystal aligning agent indicates the blending ratio (parts by mass) of each polymer with respect to the total of 100 parts by mass of the polymer components used for preparing the liquid crystal aligning agent. The liquid crystal aligning agent in each example includes a crosslinking agent (N,N,N',N'-tetrakis(2-hydroxyethyl)adipamide (a compound represented by the above formula (AD-1))) and an adhesion aid ( 5 parts by weight and 1 part by weight of 3-glycidyloxypropyltrimethoxysilane (compound represented by the above formula (AD-4)) were added to 100 parts by weight of the polymer components in total.

As shown in Table 4, the liquid crystal aligning agents of Examples 1 to 29 containing the polymer (P) had "good" liquid crystal alignment properties in liquid crystal display elements, and showed long-term afterimages at room temperature (DC relaxation characteristics) and high temperature. The short-term afterimages (DC accumulation characteristics) were all rated "excellent", "good", or "fair", and the various characteristics were well balanced. On the other hand, the liquid crystal alignment agents of Comparative Examples 1 to 14 that do not contain the polymer (P) are inferior to the examples, with either the DC relaxation property or the DC accumulation property of the liquid crystal display element being "unsatisfactory". was.

Although the mechanism by which the afterimage characteristics of the liquid crystal display elements were improved in Examples 1 to 29 is not clear, it is presumed as follows.

The polymers contained in the liquid crystal aligning agents of Examples 1 to 29 have a partial structure (U1) (a partial structure having a hole transport property) and a partial structure (U2-1) (a part having a hydrogen bonding property). structure), partial structure (U2-2) (partial structure having an acidic functional group), and partial structure (U2-3) (partial structure having a basic functional group), or It has everything. On the other hand, in the liquid crystal aligning agents of Comparative Examples 1 to 4, the polymer does not have the partial structure (U1), and in the liquid crystal aligning agents of Comparative Examples 5 to 7, the polymer has the partial structure (U2-1), In the liquid crystal aligning agents of Comparative Examples 8 to 14, which have neither the partial structure (U2-2) nor the partial structure (U2-3), the polymer has the partial structure (U2-1) and the partial structure (U2-2). ) and partial structure (U2-3).

From the viewpoint of long-term afterimage at room temperature (DC relaxation characteristics), it is preferable that the polymer has a partial structure exhibiting hole transport properties, and further has a partial structure derived from aromatic tetracarboxylic dianhydride. It is preferable. In the liquid crystal aligning agents of Examples 1 to 29, the polymer had a partial structure (U1), and the evaluation of DC relaxation properties was "fair" or higher, whereas the liquid crystal aligning agents of Comparative Examples 1 to 4 It is thought that the evaluation of the DC relaxation property of the alignment agent was "unsatisfactory" because the polymer did not have the partial structure (U1).

From the viewpoint of high-temperature short-term afterimages (DC accumulation characteristics), it is preferable that the physical properties and electrical properties of the liquid crystal alignment film are stable and difficult to change at high temperatures and under backlight, and furthermore, it is preferable that the movement of ionic impurities in the liquid crystal cell be prevented. It is preferable that maldistribution and maldistribution are suppressed. In the liquid crystal aligning agents of Examples 1 to 29, the polymer has two or all structural units among the partial structure (U2-1), the partial structure (U2-2), and the partial structure (U2-3). However, in the liquid crystal aligning agents of Comparative Examples 5 to 14, the polymer had partial structure (U2-1), partial structure (U2-2) and It is considered that the evaluation of the DC accumulation property was "unsatisfactory" because it had only one or none of the partial structures (U2-3).

In this regard, since the polymer has two or all of the structural units of the partial structure (U2-1), the partial structure (U2-2), and the partial structure (U2-3), The intermolecular interaction between the molecules was strengthened, and liquid crystal swelling and thermal expansion were suppressed, which suppressed fluctuations in physical properties and electrical properties at high temperatures and under backlight. This is thought to be due to the fact that diffusion of ionic impurities into the liquid crystal layer and movement due to the electric field were suppressed.

In addition, in the polymer (P), the amide bond or urea bond in the partial structure (U2-1) acts as a hydrogen bond donor and acceptor, and the carboxylic acid group or sulfonic acid group in the partial structure (U2-2) acts as a hydrogen bond donor and acceptor. As a bond donor and acceptor, it is believed that the basic functional group in the substructure (U2-3) can act as a hydrogen bond acceptor. Furthermore, when an acidic functional group and a basic functional group coexist, it is considered that intermolecular interactions can also be formed by acid-base interactions (ionic interactions).

From the viewpoint of liquid crystal alignment, the polymer (P) and polymer (Q) are mainly responsible for imparting and improving liquid crystal alignment, and the polymer (Q) is primarily responsible for imparting and improving electrical properties. It is preferable that the combined layer (P) and the combined layer (P) are separated into upper and lower layers. When used as a liquid crystal aligning agent containing a polymer (Q-1) having a polar group protected by a Boc group as a polymer (Q) together with the polymer (P), the hydrophobicity of the polymer (Q) increases. , it can be said that it tends to be unevenly distributed on the film surface with respect to the polymer (P), and it can be said that it becomes easier to express liquid crystal orientation. Furthermore, it is also considered that the Boc group is thermally eliminated to generate a polar group, which may contribute to crosslinking between polymers and intermolecular interaction.

Further, the liquid crystal aligning agents of Examples 26 to 29 do not have the structural unit (U1) and the structural unit (U2-2), and are closer to the substrate interface than the polymer (P) and the polymer (Q-1). It further contained a polymer (third polymer) that is likely to be unevenly distributed in the water, and the DC accumulation properties were all "excellent" or "good", indicating an excellent balance of various properties. It is presumed that by blending this third polymer, it was possible to suppress the exchange of charges (hole injection, etc.) with the ITO electrode, and further reduce the accumulation of charges. Diamines having hole-transporting properties generally have a high energy level of HOMO (highest occupied orbital), and when this energy level exceeds the work function of ITO, it is considered that hole injection from the ITO electrode is likely to occur.

[Examples 30 to 40]
A liquid crystal aligning agent was prepared in the same manner as in Example 1, except that the types and amounts of the polymer component and crosslinking agent contained in the liquid crystal aligning agent were changed as shown in Table 6 below. A liquid crystal alignment film was formed by an alignment method, and an FFS type liquid crystal display element was manufactured and various evaluations were performed. The evaluation results are shown in Table 6 below.

In Table 6, the mass ratio of each polymer in the liquid crystal aligning agent indicates the blending ratio (parts by mass) of each polymer with respect to the total of 100 parts by mass of the polymer components used for preparing the liquid crystal aligning agent. The liquid crystal alignment agent of each example contains an adhesion aid (3-glycidyloxypropyltrimethoxysilane (a compound represented by the above formula (AD-4))) at 1% per 100 parts by mass of the polymer components in total. Each part by mass was blended.

As shown in Table 6, the liquid crystal alignment agents of Examples 30 to 40 containing the polymer (P) had "good" liquid crystal alignment properties in liquid crystal display elements, and had both DC relaxation properties and DC accumulation properties. It was rated "excellent" or "good" and had a good balance in various characteristics.

From the above, it is clear that the liquid crystal aligning agent containing the polymer (P) has good liquid crystal alignment properties in liquid crystal display elements, has good DC accumulation characteristics and DC relaxation characteristics, and is unlikely to cause afterimages. Ta.

Claims (10)

Contains a polymer (P),
The polymer (P) has a partial structure represented by the following formula (1), a partial structure represented by the following formula (2), a partial structure represented by the following formula (3), and the following formula (4). A molecule that contains any one or more of the partial structures represented by the following formula (1) in the same molecule has a partial structure represented by the following formula (2). , a liquid crystal aligning agent containing any two or more of the partial structure represented by the following formula (3) and the partial structure represented by the following formula (4) in the same molecule or in different molecules.

(In formula (1), X ¹ is a tetravalent organic group. Y ¹ is a divalent organic group having a partial structure obtained by removing two hydrogen atoms from the structure represented by the following formula (Y-1). )

(In formula (Y-1), A ¹ and A ² are each independently a monovalent group having an aromatic hydrocarbon ring, and the aromatic hydrocarbon ring is the nitrogen in formula (Y-1). A ¹ and A 2 are combined with each other to represent a nitrogen-containing fused heterocyclic structure formed with the nitrogen atom to which A ¹ and ^{A 2 are} bonded. A ³ is a hydrogen atom or A monovalent organic group.However, when A ¹ and A ² are combined with each other to represent a nitrogen-containing fused heterocyclic structure constituted with the nitrogen atom to which A ¹ and A ² are bonded, the nitrogen-containing fused heterocycle is a monovalent organic group. The structure has two or more aromatic hydrocarbon rings, and the two aromatic hydrocarbon rings of the nitrogen-containing fused heterocyclic structure are bonded together by sharing the nitrogen atom in formula (Y-1). structure, or ^A3 has an aromatic hydrocarbon ring, and the aromatic hydrocarbon ring of ^A3 is bonded to the nitrogen atom in formula (Y-1).)

(In formula (2), formula (3) and formula (4), X ² , X ³ and X ⁴ are each independently a tetravalent organic group. Y ² has a chain hydrocarbon structure and " * ¹ -NR ¹ -CO-", "* ¹ -CO-NR ¹ -", "* ¹ -NR ¹ -CO-NR ² -" or "* ¹ -CO-NR ¹ -NR ² -CO-" is a divalent group containing adjacent partial structures in the main chain. R ¹ and R ² are each independently a hydrogen atom or a monovalent organic group. "* ¹ " is a chain hydrocarbon structure represents a bond with Y ³ is a divalent organic group having a carboxylic acid group or a sulfonic acid group. Y ⁴ is a nitrogen-containing heterocycle, "-R ³ -NR ⁴ -R ⁵ -" and A divalent organic group having at least one partial structure selected from the group consisting of "-R ⁶ -NR ⁷ R ⁸ " (excluding the group corresponding to Y ² ). R ³ , R ⁵ and R ⁶ are each independently a divalent aliphatic hydrocarbon group. R ⁴ , R ⁷ and R ⁸ are each independently a hydrogen atom, a thermally releasable group, or a monovalent aliphatic group. It is a hydrocarbon group.) The polymer (P) has a partial structure represented by the above formula (1), a partial structure represented by the above formula (2), a partial structure represented by the above formula (3), and a partial structure represented by the above formula (2) in the same molecule. The liquid crystal aligning agent according to claim 1, comprising any two or more of the partial structures represented by the above formula (4). The liquid crystal aligning agent according to claim 1, wherein the polymer (P) contains a structural unit derived from aromatic tetracarboxylic dianhydride. The liquid crystal aligning agent according to claim 1, further comprising a polymer (Q) different from the polymer (P). A claim in which the polymer (Q) contains at least one kind selected from the group consisting of a partial structure represented by the following formula (5) and a partial structure represented by the following formula (6). Item 4. Liquid crystal aligning agent according to item 4.

(In formulas (5) and (6), X ⁵ and X ⁶ are each independently a tetravalent group having an alicyclic structure. Y ⁵ and Y ⁶ are each independently a nitrogen atom (It is a divalent organic group containing a partial structure in which a thermally releasable group is bonded to.) The liquid crystal aligning agent according to claim 5, wherein the alicyclic structure is a substituted or unsubstituted cyclobutane ring structure. A claim further comprising a compound having three or more in one molecule at least one selected from the group consisting of oxiranyl group, oxetanyl group, hydroxy group, mercapto group, amino group, and polymerizable carbon-carbon double bond group. Item 1. Liquid crystal aligning agent according to item 1. The liquid crystal aligning agent according to claim 1, further comprising a compound having a trialkoxysilyl group. 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.