WO2024219400A1 - Liquid crystal aligning agent, liquid crystal alignment film, and liquid crystal display element - Google Patents

Abstract

Provided are: a liquid crystal aligning agent that contains two or more kinds of polyamic acids and in which deterioration of liquid crystal orientation during storage at room temperature is suppressed; a liquid crystal alignment film obtained from the liquid crystal aligning agent; and a liquid crystal display element.　The liquid crystal aligning agent contains a polymer (A) and a polymer (B) as indicated below.　Polymer (A): A polyamic acid (A) having a structural unit derived from a tetracarboxylic acid derivative and a structural unit derived from a diamine, the polyamic acid (A) containing: a structural unit (a-1Ta) represented by the formula (1T_a) as the structural unit derived from the tetracarboxylic acid derivative; and a structural unit (a-1Da) represented by the formula (1D_a) as the structural unit derived from the diamine. At least some of the terminals of the polyamic acid (A) contain a non-amino group, the non-amino group being a functional group represented by the structural formula (E), and the abundance ratio of the terminal amino group of the polyamic acid (A) with respect to all of the terminals of the polyamic acid (A) is 60% or less.　Polymer (B): A polyamic acid (B) having a structural unit derived from a tetracarboxylic acid derivative and a structural unit derived from a diamine, the polyamic acid containing: a structural unit (b-1Tb) represented by the formula (1T_b) as the structural unit derived from the tetracarboxylic acid derivative; and a structural unit (b-1Db) represented by the formula (1D_b) as the structural unit derived from the diamine.

Description

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

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

Liquid crystal display devices have been widely used as display units for personal computers, smartphones, mobile phones, television receivers, etc. Liquid crystal display devices include, for example, a liquid crystal layer sandwiched between an element substrate and a color filter substrate, pixel electrodes and a common electrode that apply an electric field to the liquid crystal layer, an alignment film that controls the orientation of the liquid crystal molecules in the liquid crystal layer, and thin film transistors (TFTs) that switch the electric signals supplied to the pixel electrodes. Known methods for driving liquid crystal molecules include vertical electric field methods such as the TN (Twisted Nematic) method and the VA (Vertical Alignment) method, and horizontal electric field methods such as the IPS (In-Plane Switching) method and the FFS (Fringe Field Switching) method.

Currently, the most widely used industrial liquid crystal alignment film is produced by performing an alignment treatment on the surface of a film made of a polymer, typically polyamic acid and/or polyimide obtained by imidizing it, formed on an electrode substrate. In recent years, as liquid crystal display elements have become more powerful, precise, and large, photo-alignment methods that impart liquid crystal alignment ability by irradiating polarized radiation have been investigated. Proposed photo-alignment methods include those that utilize a photoisomerization reaction, a photocrosslinking reaction, and a photodecomposition reaction (see, for example, Non-Patent Document 1 and Patent Document 1).

Japanese Patent Application Publication No. 9-297313

"Liquid crystal photoalignment film" Kidowaki, Ichimura, Functional Materials, November 1997, Vol. 17, No. 11, pp. 13-22

Conventionally, liquid crystal alignment agents containing polyimide have been actively studied as liquid crystal alignment agents for liquid crystal alignment films used in in-plane switching liquid crystal display elements. However, while polyimide has excellent liquid crystal alignment properties, it has the disadvantage of poor solubility in organic solvents. Therefore, when dissolving polyimide in an organic solvent, a highly soluble polar organic solvent such as N-methylpyrrolidone is used. However, polar organic solvents have the disadvantage of high solubility but high hygroscopicity. Therefore, when preparing a liquid crystal alignment film using a liquid crystal alignment agent containing the above polar organic solvent, it is necessary to control the application environment of the liquid crystal alignment agent from the viewpoint of improving the performance of the obtained liquid crystal alignment film. In particular, when the application is performed in a high humidity environment, the solubility of the liquid crystal alignment agent decreases due to moisture absorption before heat treatment, polyimide precipitates, and the liquid crystal alignment film becomes white (hygroscopic whitening) may occur.
Furthermore, the production of polyimide requires large amounts of reagents and large production facilities, which poses problems in terms of handling (safety, environmental impact, equipment costs, etc.).
In view of the above circumstances, the present inventors have focused on a liquid crystal aligning agent using a polyamic acid. However, it has become clear that, when a liquid crystal aligning agent containing two or more kinds of polyamic acids having different characteristics is used, the liquid crystal alignment property deteriorates during storage, although it is preferable from the viewpoints of suppressing the above-mentioned whitening due to moisture absorption and ease of handling.
In particular, liquid crystal alignment films used in liquid crystal display elements such as those of the IPS and FFS modes require a high alignment control force to suppress image retention caused by long-term AC driving (hereinafter also referred to as AC image retention), but it has become clear that there is a problem in that it is not always possible to obtain a film that meets such high level requirements.

In view of the above, the object of the present invention is to provide a liquid crystal alignment agent containing two or more types of polyamic acid, which suppresses deterioration of liquid crystal alignment properties during storage at room temperature, a liquid crystal alignment film obtained from the liquid crystal alignment agent, and a liquid crystal display element.

As a result of intensive research conducted by the present inventors to achieve the above object, it was discovered that using a liquid crystal alignment agent containing a first polyamic acid having a specific non-amino terminal structure and a structural unit derived from a specific tetracarboxylic acid derivative and a structural unit derived from a diamine, and a second polyamic acid having a structural unit derived from a specific tetracarboxylic acid derivative and a structural unit derived from a diamine, is extremely effective in achieving the above object, and the present invention was completed.

（式中Ｘ_ａは、下記式（ｘ－１）で表される４価の有機基を表す。式（１Ｄ_ａ）中、Ｙ_ａはジアミン由来の２価の有機基を表す。Ｚはそれぞれ独立して、水素原子又は１価の有機基を表す。）

（式（ｘ－１）中、Ｒ_１～Ｒ_４はそれぞれ独立して、水素原子、ハロゲン原子、炭素数１～６のアルキル基、炭素数２～６のアルケニル基、炭素数２～６のアルキニル基、フッ素原子を含有する炭素数１～６の１価の有機基、炭素数１～６のアルコキシ基、炭素数２～６のアルコキシアルキル基、炭素数２～６のアルキルオキシカルボニル基、又はフェニル基を表し、Ｒ_１～Ｒ_４の少なくとも一つは上記定義中の水素原子以外の基を表す。＊は結合手を表す。）

（式中Ｘ_ｂは、芳香族テトラカルボン酸二無水物由来の４価の有機基、下記式（ｘ－２）で表される４価の有機基、又は５員環以上の脂環構造を有する４価の有機基（Ｔ_５ａ）を表す。式（１Ｄ_ｂ）中、Ｙ_ｂはジアミン由来の２価の有機基を表す。Ｚは上記式（１Ｄ_ａ）のＺと同義である。）

（式（Ｅ）中、Ｑは、下記の基（ｅ１）～（ｅ３）のいずれかから選ばれる１価の有機基である。＊は結合手を表す。）
　（ｅ１）炭素数１～６の非環式炭化水素基
　（ｅ２）カルボキシ基を１～２つ有し、且つ、炭素数が２～３０の１価の有機基（但し、該１価の有機基は酸無水基を含まない。）
　（ｅ３）Ｂｏｃを２つ以上有し、且つ、Ｂｏｃを除く炭素数が１～３０の１価の有機基であって、上記１価の有機基は、＊１－ＮＨ（Ｂｏｃ）、＊１－Ｎ（Ｂｏｃ）_２、及び「＊１－Ｎ（Ｂｏｃ）－＊１」（＊１は、炭素原子に結合する結合手を表す。）からなる群から選ばれる保護アミノ部位を有する。なお、保護アミノ部位が２つ以上である場合、各保護アミノ部位は同一であっても良く、異なっていても良い。 The present invention includes the following aspects.
A liquid crystal aligning agent comprising the following polymer (A) and polymer (B):
Polymer (A): A polyamic acid (A) having a structural unit derived from a tetracarboxylic acid derivative and a structural unit derived from a diamine,
The structural unit (a-1Ta) represented by the following formula (1T _a ) is contained as a structural unit derived from a tetracarboxylic acid derivative,
The diamine-derived structural unit includes a structural unit (a-1Da) represented by the following formula (1D _a ):
At least a part of the terminals of the polyamic acid (A) contains a non-amino group, and the non-amino group is a functional group represented by the following structural formula (E):
The polyamic acid (A), wherein the proportion of terminal amino groups present in the polyamic acid (A) is 60% or less based on all terminals of the polyamic acid (A).
Polymer (B): A polyamic acid (B) having a structural unit derived from a tetracarboxylic acid derivative and a structural unit derived from a diamine,
The structural unit (b-1Tb) represented by the following formula (1T _b ) is contained as a structural unit derived from a tetracarboxylic acid derivative,
The above polyamic acid, which contains a structural unit (b-1Db) represented by the following formula (1D _b ) as a structural unit derived from a diamine:

(In the formula, _Xa represents a tetravalent organic group represented by the following formula (x-1). In formula ( _1Da ), _Ya represents a divalent organic group derived from a diamine. Each Z independently represents a hydrogen atom or a monovalent organic group.)

(In formula (x-1), R ₁ to R ₄ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, a monovalent organic group having 1 to 6 carbon atoms containing a fluorine atom, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 6 carbon atoms, an alkyloxycarbonyl group having 2 to 6 carbon atoms, or a phenyl group, and at least one of R ₁ to R ₄ represents a group other than a hydrogen atom as defined above. * represents a bond.)

(In the formula, _Xb represents a tetravalent organic group derived from an aromatic tetracarboxylic dianhydride, a tetravalent organic group represented by the following formula (x-2), or a tetravalent organic group ( _T5a ) having an alicyclic structure having five or more members. In formula ( _1Db ), _Yb represents a divalent organic group derived from a diamine. Z has the same meaning as Z in formula ( _1Da ).)

(In formula (E), Q is a monovalent organic group selected from the following groups (e1) to (e3). * represents a bond.)
(e1) an acyclic hydrocarbon group having 1 to 6 carbon atoms; (e2) a monovalent organic group having 1 to 2 carboxy groups and 2 to 30 carbon atoms (however, the monovalent organic group does not include an acid anhydride group).
(e3) A monovalent organic group having two or more Boc groups and having 1 to 30 carbon atoms excluding Boc, the monovalent organic group having a protected amino moiety selected from the group consisting of *1-NH(Boc), *1-N(Boc) ₂ and *1-N(Boc)-*1 (*1 represents a bond bonded to a carbon atom). When there are two or more protected amino moieties, the protected amino moieties may be the same or different.

The present invention provides a liquid crystal alignment agent containing two or more types of polyamic acid, which suppresses deterioration of liquid crystal alignment properties during storage at room temperature, a liquid crystal alignment film obtained from the liquid crystal alignment agent, and a liquid crystal display element.

1 is a schematic cross-sectional view showing an example of an IPS mode in-plane switching liquid crystal display element having a liquid crystal alignment film obtained from the liquid crystal aligning agent of the present invention. 1 is a schematic cross-sectional view showing an example of an FFS mode in-plane switching liquid crystal display element having a liquid crystal alignment film obtained from the liquid crystal aligning agent of the present invention.

Hereinafter, a liquid crystal alignment agent containing a specific polymer component, a liquid crystal alignment film formed using the liquid crystal alignment agent, and a liquid crystal display element having the liquid crystal alignment film will be described in detail. However, the explanation of the constituent elements described below is an example of one embodiment of the present invention, and the present invention is not limited to these contents.
In the following description, examples of a "halogen atom" include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Furthermore, "tert-" meaning tertiary is also represented as "t-". "Boc" represents a tert-butoxycarbonyl group, and "*" represents a bond.

(Terminal Amino Group)
The liquid crystal aligning agent of the present invention contains the above polymer (A) and polymer (B). At least a part of the terminals of the polyamic acid (A) in the polymer (A) contains a non-amino group, and the non-amino group is a functional group represented by the above structural formula (E). That is, preferably, at least a part of the terminal amino groups of the polyamic acid (A) are modified to have the non-amino group.
The proportion of terminal amino groups in the polyamic acid (A) is 60% or less based on all the terminals of the polyamic acid (A).
At least a part of the terminals of the polyamic acid (B) in the polymer (B) of the present invention may contain the non-amino group. That is, preferably, at least a part of the terminal amino groups of the polyamic acid (B) may be modified to have the non-amino group.
The non-amino group which the terminal of the polyamic acid (B) may contain, from the viewpoint of suitably obtaining the effects of the present invention, may be a functional group represented by structural formula (E) exemplified for the polyamic acid (A) in the polymer (A), and a similar functional group may be used as a preferred embodiment.

The term "abundance of terminal amino groups" as used herein means, for example, in the case of polyamic acid (A), the proportion of terminals that are amino groups expressed as a percentage based on all terminals of polyamic acid (A).
The phrase "based on all of the terminals of the polyamic acid (A)" means that the total number of amino terminals and non-amino terminals of the polyamic acid (A) is taken as 100%, and includes the case where any terminal is 0%.
The abundance of terminal amino groups can be estimated from the amount of change in peak intensity of terminal amino groups using ¹ H-NMR. The abundance of terminal amino groups in the polyamic acid (A) used in the present invention is preferably 30% or less, more preferably 10% or less, and even more preferably 1% or less. The abundance of terminal amino groups in the polyamic acid (A) used in the present invention may be 0%. That is, all of the terminals of the polyamic acid (A) used in the present invention may contain the non-amino group.

The non-amino group is a functional group represented by the above structural formula (E). The functional group represented by the above structural formula (E) is preferably bonded to a nitrogen atom of the diamine residue.
Preferred specific examples of the above (e1) include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a vinyl group, and a methacryl group.
Preferred specific examples of the above (e1) include residues derived from acyclic aliphatic dicarboxylic acid anhydrides such as acetic anhydride, acrylic anhydride, methacrylic anhydride, propionic anhydride, butyric anhydride, valeric anhydride, isovaleric anhydride, hexanoic anhydride, or heptanoic anhydride.

A preferred specific example of the above (e2) is a monovalent organic group having a residue derived from a dicarboxylic acid anhydride and having one or two carboxy groups (however, the monovalent organic group does not include an acid anhydride group).
Specific examples of dicarboxylic acid anhydrides that give the above (e2) include a compound (e2-1) that does not have an alkoxysilane structure and a compound (e2-2) that has an alkoxysilane structure.
Specific examples of the compound (e2-1) include aromatic or aliphatic cyclic dicarboxylic acid anhydrides such as phthalic anhydride, maleic anhydride, succinic anhydride, allylsuccinic anhydride, itaconic anhydride, trimellitic anhydride, 1,2,4-cyclohexanetricarboxylic acid-1,2-anhydride, 4-ethynylphthalic anhydride, and cyclohexene-1,2-dicarboxylic acid anhydride.
The aliphatic ring in the aliphatic cyclic dicarboxylic acid anhydride may be a saturated aliphatic ring or an unsaturated aliphatic ring.
Specific examples of compound (e2-2) include 3-trimethoxysilylpropyl succinic anhydride, 3-triethoxysilylpropyl succinic anhydride, 4-(3-trimethoxysilylpropyl)cyclohexane-1,2-dicarboxylic anhydride, 4-(3-triethoxysilylpropyl)cyclohexane-1,2-dicarboxylic anhydride, 4-(3-trimethoxysilylpropyl)phthalic anhydride, 4-(3-triethoxysilylpropyl)phthalic anhydride; 2-(methoxydimethylsilyl)ethyl succinic anhydride, 3-(dimethylmethoxysilyl)propyl succinic anhydride, and 3-(dimethylethoxysilyl)propyl succinic anhydride, such as (C1 to C6)alkoxydimethylsilyl(C2 to C8)alkyl succinic anhydrides; 2-(dimethoxymethylsilyl)ethyl anhydride. Examples of the di(C1-6)alkoxymethylsilyl(C2-8)alkyl succinic anhydride such as succinic acid; tri(C1-6)alkoxysilyl(C2-8)alkyl succinic anhydride such as 2-(trimethoxysilyl)ethyl succinic anhydride, 2-(triethoxysilyl)ethyl succinic anhydride, [3-(trimethoxysilyl)propyl]succinic anhydride, or [3-(triethoxysilyl)propyl]succinic anhydride; 4-(3-dimethylmethoxysilylpropyl)cyclohexane-1,2-dicarboxylic anhydride, 4-(3-dimethylethoxysilylpropyl)cyclohexane-1,2-dicarboxylic anhydride, 4-(3-dimethylethoxysilylpropyl)phthalic anhydride, or 4-(3-dimethylethoxysilylpropyl)phthalic anhydride.

In the above (e3), from the viewpoint of optimally obtaining the effects of the present invention, the number of protected amino moieties is one or more, and from the viewpoint of the effect of liquid crystal alignment, the number of protected amino moieties is preferably four or less.
The above (e3) can be obtained, for example, by using an active ester compound (e) represented by R—O—C(═O)-E3 (R represents an active ester forming group, and E3 represents the above (e3)).

Here, "active ester forming group" means a chemical group that, together with the carbonyl group to which it is attached, forms an ester that activates the carbonyl group for coupling reactions with amino-containing compounds to form amide groups or other coupling reactions.

Examples of the active ester-forming group include groups obtained by removing a hydroxy group from a hydroxy compound such as 1-hydroxybenzotriazole (HOBt), 1-hydroxy-7-azabenzotriazole (HOAt), N-hydroxysuccinimide (HOSu), ethyl 2-cyano-2-(hydroxyimino)acetate (oxyma), 3,4-dihydro-3-hydroxy-4-oxo-1,2,3-benzotriazine (HOOBt or HODhbt), N-hydroxy-5-norbornene-2,3-dicarboximide (HONB), 2,3,4,5,6-pentafluorophenol (HOPfp), or 6-chloro-1-hydroxy-1H-benzotriazole (Cl-HOBt) (see, for example, WATANABE Chemical's catalog, Amino acids and chiral building blocks to new medicine. Hereinafter, these are collectively referred to as hydroxy compounds (Ae)). Among these, from the viewpoint of suitably obtaining the effects of the present invention, groups obtained by removing a hydroxy group from HOBt, HOAt, HOSu or HOOBt are preferred, and groups obtained by removing a hydroxy group from HOBt, HOAt or HOOBt are more preferred.
When the active ester forming group represents a group derived from HOSu, E3 more preferably has two or more of the above-mentioned protected amino moieties, from the viewpoint of suitably achieving the effects of the present invention.

The active ester compound (e3) is synthesized, for example, from a carboxylic acid represented by "W-COOH" (W has the same meaning as the above (e3). Hereinafter, this is also referred to as carboxylic acid (W)) and the above hydroxy compound (Ae).
The organic group having 1 to 30 carbon atoms excluding the Boc group in W is preferably an organic group having 1 to 12 carbon atoms, and more preferably an organic group having 1 to 6 carbon atoms.
The above carboxylic acid (W) has two or more Boc groups and has a group having a protected amino moiety selected from the group consisting of *1-NH(Boc), *1-N(Boc) ₂ , and "*1-N(Boc)-*1" (*1 represents a bond bonded to a carbon atom) in the molecule.
The carboxylic acid (W) can be obtained by protecting the amino groups of a carboxy-containing polyamine (pA) having two or more amino groups, such as a carboxy-containing diamine. The amino groups may be protected either partially or entirely.

Specific examples of polyamines (pA) include diaminobenzoic acids such as 3,5-diaminobenzoic acid; carboxybiphenyl compounds such as 4,4'-diaminobiphenyl-3-carboxylic acid; carboxydiphenylalkanes such as 4,4'-diaminodiphenylmethane-3-carboxylic acid or 4,4'-diaminodiphenylethane-3-carboxylic acid; aromatic polyamines such as carboxydiphenyl ethers such as 4,4'-diaminodiphenylether-3-carboxylic acid or 4,4'-diaminodiphenylether-3-carboxylic acid; and aliphatic polyamines such as arginine, lysine, ornithine, or histidine.

From the viewpoint of obtaining the effects of the present invention, the carboxylic acid (W) and the polyamine (pA) preferably have a nitrogen atom-containing heterocycle or a derivative thereof.Specific examples of the nitrogen atom-containing heterocycle include aziridine, azetidine, pyrrole, imidazole, imidazolidine, pyrrolidine, piperidine, piperazine, morpholine, pyrazole, indole, benzimidazole, and carbazole.Specific examples of the derivative of the nitrogen atom-containing heterocycle include compounds in which any hydrogen atom of the nitrogen atom-containing heterocycle is replaced by a substituent.
Examples of the substituent include a linear or branched alkyl group having 1 to 4 carbon atoms, a linear or branched alkoxy group having 1 to 4 carbon atoms, a hydroxyl group, a halogen atom, a nitro group, a cyano group, a trifluoromethyl group, -NR ₇ R ₈ , or a -CONR ₇ R ₈ group, where R ₇ and R ₈ each independently represent a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms.

Preferred specific examples of the active ester compound (e3) are any of the compounds represented by the following formulae (e3-1) to (e3-4).

<Polyamic Acid (A)>
(Structural Unit Derived from Tetracarboxylic Acid Derivative Contained in Polyamic Acid (A))
The polyamic acid (A) in the polymer (A) of the present invention has a structural unit (a-1Ta) represented by the above formula (1T _a ) as a structural unit derived from a tetracarboxylic acid derivative. The polymer (A) may be composed of one or more types of structural units, and the structural unit (a-1Ta) may be one or more types.

_Xa in the above formula (1T _a ) represents a tetravalent organic group represented by the above formula (x-1).
Specific examples of the alkyl group having 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms, in R ₁ to R ₄ in formula (x- ₁ ) include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a t-butyl group, an n-pentyl group, etc. Specific examples of the alkenyl group having 2 to 6 carbon atoms, preferably 2 to 4 carbon atoms, in R 1 to R ₄ include a vinyl group, a propenyl group, a butynyl group, etc., which may be linear or branched. Specific examples of the alkynyl group having 2 to 6 carbon atoms, preferably 2 to 4 carbon atoms, in R ₁ to R ₄ include an ethynyl group, a 1-propynyl group, a 2-propynyl group, etc.
In the above R ₁ to R ₄ , examples of the monovalent organic group containing a fluorine atom and having 1 to 6, preferably 1 to 4, carbon atoms include a fluoromethyl group, a trifluoromethyl group, a trifluoromethoxy group, a 2,2,2-trifluoroethyl group, a 2,2,2-trifluoroethoxy group, a pentafluoroethyl group, and a pentafluoropropyl group.

The above formula (x-1) is preferably selected from the group consisting of the following formulas (x1-1) to (x1-5).

From the viewpoint of optimally obtaining the effects of the present invention, the structural unit (a-1Ta) contained in the polyamic acid (A) of the present invention is preferably 60 mol% or more, more preferably 70 mol% or more, and most preferably 100 mol% relative to 1 mole of all structural units derived from the tetracarboxylic acid derivative contained in the polyamic acid (A).

（式中Ｘ_2ａは、上記式（ｘ－１）で表される４価の有機基以外のテトラカルボン酸二無水物由来の４価の有機基を表す。） The polyamic acid (A) of the present invention may have a structural unit (a-2Ta) represented by the following formula (2T _a ) as a structural unit derived from a tetracarboxylic acid derivative. The structural unit (2-1Ta) may be of one type or of two or more types.

(In the formula, _X2a represents a tetravalent organic group derived from a tetracarboxylic dianhydride other than the tetravalent organic group represented by the above formula (x-1).)

Specific examples of the tetravalent organic group for _X2a in the above formula (2T _a ) include a tetravalent organic group (T _5a ) having an alicyclic structure with five or more members, and a tetravalent organic group obtained by removing two acid anhydride groups from the following tetracarboxylic dianhydrides (hereinafter collectively referred to as "other tetracarboxylic dianhydrides").

acyclic aliphatic tetracarboxylic dianhydrides such as 1,2,3,4-butanetetracarboxylic dianhydride or tetracarboxylic dianhydrides represented by the following formulae (AL-1) to (AL-7); alicyclic tetracarboxylic dianhydrides such as 1,2,3,4-cyclobutanetetracarboxylic dianhydride (provided that the tetravalent organic group ( _T ) excluding tetracarboxylic dianhydrides having the above structure. ) ; pyromellitic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfone tetracarboxylic dianhydride, 1,4,5,8-naphthalene tetracarboxylic dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride, 3,3',4,4'-perfluoroisopropylidenedi(phthalic anhydride), 3,3',4,4'-biphenyl tetracarboxylic dianhydride, 2,2',3,3'-biphenyl aromatic tetracarboxylic dianhydrides such as 4,4'-bis(3,4-dicarboxyphenoxy)-2,2-diphenylpropane dianhydride, ethylene glycol bisanhydrotrimellitate, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 4,4'-carbonyldiphthalic anhydride, 4,4'-oxydi(1,4-phenylene)bis(phthalic acid) dianhydride, or 4,4'-methylenedi(1,4-phenylene)bis(phthalic acid) dianhydride; and tetracarboxylic dianhydrides described in JP 2010-97188 A.

More preferred examples of the above other tetracarboxylic dianhydrides include 1,2,3,4-butane tetracarboxylic dianhydride, 1,2,3,4-cyclobutane tetracarboxylic dianhydride, pyromellitic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfone tetracarboxylic dianhydride, 1,4,5,8-naphthalene tetracarboxylic dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride, 3,3',4,4'-biphenyl tetracarboxylic dianhydride, and 2,2',3,3'-biphenyl tetracarboxylic dianhydride.

The tetravalent organic group (T _5a ) is preferably a tetravalent organic group having a 5- to 8-membered alicyclic structure, and more preferably a tetravalent organic group having a 5- to 7-membered alicyclic structure. The 5- or more-membered alicyclic structure means that, when the alicyclic structure to which the acid anhydride group is bonded is a polycyclic structure, each of the rings contained in the polycyclic structure has 5 or more atoms constituting the ring. The alicyclic structure may be bonded to at least one of the two acid anhydride groups, and may have a chain hydrocarbon structure or an aromatic ring structure together with the alicyclic structure.
Preferred specific examples of the tetravalent organic group (T _5a ) include tetravalent organic groups represented by any of the following formulas (X _5a -1) to (X _5a -18). From the viewpoint of suitably obtaining the effects of the present invention, the tetravalent organic group (T _5a ) is more preferably (X _5a -1) to (X _5a -4).

The proportion of the structural unit represented by formula (2T _a ) contained in the polyamic acid (A) is preferably 40 mol % or less, and more preferably 30 mol % or less, based on 1 mol of all structural units derived from tetracarboxylic acid derivatives contained in the polyamic acid (A).

Details of the diamine-derived structural units contained in polyamic acid (A) will be described later.

<Polyamic Acid (B)>
(Structural Units Derived from Tetracarboxylic Acid Derivatives Contained in Polyamic Acid (B))
The liquid crystal aligning agent of the present invention contains, together with the above-mentioned polyamic acid (A), a polyamic acid (B) having a structural unit derived from a tetracarboxylic acid derivative and a structural unit derived from a diamine, the polyamic acid including, as the structural unit derived from the tetracarboxylic acid derivative, a structural unit (b-1Tb) represented by the above-mentioned formula (1T _b ).
The polyamic acid (B) may be composed of one kind or two or more kinds. In addition, each of the structural units constituting the polyamic acid (B) may be composed of one kind or two or more kinds.

Examples of the tetravalent organic group that provides X _b in the above formula (1T _b ) include a tetravalent organic group obtained by removing two anhydride groups (-C(═O)-O-C(═O)-) from an aromatic tetracarboxylic dianhydride, a tetravalent organic group obtained by removing two anhydride groups from 1,2,3,4-cyclobutane tetracarboxylic dianhydride, and a tetravalent organic group obtained by removing two anhydride groups from a tetracarboxylic dianhydride having the above tetravalent organic group (T _5a ).
Here, the aromatic tetracarboxylic dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxy groups, including at least one carboxy group bonded to an aromatic ring.
From the viewpoint of obtaining the effects of the present invention, the tetravalent organic group derived from an aromatic tetracarboxylic dianhydride in Xb is preferably a tetracarboxylic dianhydride having a benzene ring. More preferably, the tetravalent organic group derived from an aromatic tetracarboxylic dianhydride in _Xb is a tetravalent organic group obtained by removing two anhydride groups from the aromatic tetracarboxylic dianhydride exemplified as _X2a in the above formula (2T _{a )} .

In order to obtain the effects of the present invention, the polyamic acid (B) preferably contains more than 40 mol % of the structural unit (b-1Tb) relative to 1 mole of all structural units derived from the tetracarboxylic acid derivative contained in the polyamic acid (B), and more preferably contains 50 mol % or more of the structural unit (b-1Tb).

（式中Ｘ_２ｂは、Ｘ_ｂ以外の４価の有機基を表す。） The polyamic acid (B) of the present invention may have a structural unit (b-2Tb) represented by the following formula (2T _b ) as a structural unit derived from a tetracarboxylic acid derivative.

(In the formula, _X2b represents a tetravalent organic group other than _Xb .)

Specific examples of the tetravalent organic group of X _2b in the above formula (2T _b ) include a tetravalent organic group obtained by removing two anhydride groups from an acyclic aliphatic tetracarboxylic acid dianhydride, a tetravalent organic group represented by the above formula (X-2), and a tetravalent organic group other than the above tetravalent organic group (T _5a ), which is obtained by removing two anhydride groups from an alicyclic tetracarboxylic acid dianhydride.
Here, the acyclic aliphatic tetracarboxylic acid dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxy groups bonded to a chain hydrocarbon structure, but is not necessarily composed of a chain hydrocarbon structure alone, and may have an alicyclic structure or an aromatic ring structure as a part thereof.
Alicyclic tetracarboxylic dianhydrides are acid dianhydrides obtained by intramolecular dehydration of four carboxy groups, including at least one carboxy group bonded to an alicyclic structure. However, none of these four carboxy groups are bonded to an aromatic ring. In addition, they do not necessarily have to be composed of an alicyclic structure alone, and may have a chain hydrocarbon structure or an aromatic ring structure as part of them.
From the viewpoint of suitably obtaining the effects of the present invention, the tetravalent organic group for _X2b is preferably a tetravalent organic group obtained by removing two anhydride groups from a tetracarboxylic acid dianhydride having at least one partial structure selected from the group consisting of a substituted cyclobutane ring structure and a cyclobutene ring structure, or a tetravalent organic group obtained by removing two anhydride groups from an acyclic aliphatic tetracarboxylic acid dianhydride exemplified as the other tetracarboxylic acid dianhydrides described above.
More preferred _X2b is a tetravalent organic group represented by the above formula (x-1) or a tetravalent organic group obtained by removing two anhydride groups from the acyclic aliphatic tetracarboxylic acid dianhydrides exemplified above as the other tetracarboxylic acid dianhydrides.

In order to obtain the effects of the present invention, the polyamic acid (B) preferably contains less than 60 mol % of the structural unit (b-2Tb) relative to 1 mol of all structural units derived from the tetracarboxylic acid derivative contained in the polyamic acid (B), and more preferably contains 50 mol % or less of the structural unit (b-2Tb).

Details of the diamine-derived structural units contained in polyamic acid (B) will be described later.

(Structural Units Derived from Diamines Contained in Polyamic Acid (A) and Polyamic Acid (B))
The polyamic acid (A) in the polymer (A) of the present invention has a structural unit (a-1Da) represented by the above formula (1D _a ) as a structural unit derived from a diamine. The structural unit (a-1D _a ) may be of one type or of two or more types.

The monovalent organic group for Z in the above formula (1D _a ) is a monovalent hydrocarbon group having 1 to 6 carbon atoms, a methylene group of the hydrocarbon group being -O-, -S-, -CO-, -COO-, -COS-, -NR ³ -, -CO-NR ³ -, -Si(R ³ ) ₂ - (wherein R ³ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms. When there are two R ^3s , R ^3s may be the same or different), -SO ₂ - or the like; a monovalent group in which at least one hydrogen atom bonded to a carbon atom of the above-mentioned monovalent hydrocarbon group or the above-mentioned monovalent group A is substituted with a halogen atom, a hydroxy group, an alkoxy group, a nitro group, an amino group, a mercapto group, a nitroso group, an alkylsilyl group, an alkoxysilyl group, a silanol group, a sulfino group, a phosphino group, a carboxy group, a cyano group, a sulfo group, an acyl group, or the like; and a monovalent group having a heterocycle.
As the monovalent organic group for Z in the above formula (1D _a ), an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, or a t-butoxycarbonyl group is preferable, an alkyl group having 1 to 3 carbon atoms is more preferable, and a methyl group is even more preferable.
In order to suitably obtain the effects of the present invention, the two Z's in the above formula (1D _a ) are each independently preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and more preferably a hydrogen atom or a methyl group.

The polyamic acid (B) in the polymer (B) of the present invention has a structural unit (b-1Db) represented by the above formula (1D _b ) as a structural unit derived from a diamine. The structural unit (b-1Db) may be of one type or of two or more types. The monovalent organic group of Z in the above formula (1D _b ) has the same meaning as Z in the above formula (1D _a ).

Examples of the structural units of the structural unit (a-1Da) and the structural unit (b-1Db) include structural units (1D-1) derived from diamines selected from the group consisting of diamines represented by diamine (0) "H-N(Z)-Ar ₁ -L ₁ -A-L _1' -Ar _1' -N(Z)-H", diamine (Ph) "H-N(Z)-Ar-N(Z)-H", and diamine (0)'"H-N(Z)-Ar ₂ -L ₂ -A ₂ -L _2' -Ar _2' -N(Z)-H", or structural units (1D-2) derived from diamines other than the diamine (0), diamine (Ph), and diamine (0)' (hereinafter also referred to as other diamines), with the structural unit (1D-1) being more preferred.
Here, Ar ₁ and Ar _1' each independently represent a benzene ring, a biphenyl structure, or a naphthalene ring. Any hydrogen atom on the ring of _{Ar 1} or Ar _1' may be substituted with a monovalent group. A represents a divalent organic group having an alkylene structure and having 1 to 10 carbon atoms.
L ₁ and L _1' each independently represent a single bond, -O-, -S-, -C(=O)-, -O-C(=O)-, -NR- (R represents a hydrogen atom or a monovalent organic group), -C(=O)-NR- (R represents a hydrogen atom or a monovalent organic group), or -NR-C(=O)- (R represents a hydrogen atom or a monovalent organic group).

(Diamine (0))
Examples of the monovalent organic group for R in -NR-, -C(═O)-NR-, or -NR-C(═O)- representing L ₁ and L _1' in the diamine (0) include an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, an alkenyl group having 2 to 3 carbon atoms, an acyl group having 2 to 3 carbon atoms, an alkylsilyl group having 1 to 3 carbon atoms, an alkoxysilyl group having 1 to 3 carbon atoms, a Boc group, or a monovalent organic group in which at least a portion of the hydrogen atoms in these groups have been substituted with at least one of a halogen atom and a hydroxy group.

Examples of the monovalent group that is a substituent for any hydrogen atom on the rings of Ar ₁ and Ar _1' in the diamine (0) include monovalent groups such as a halogen atom; an alkyl group having 1 to 3 carbon atoms; an alkyl group having 1 to 3 carbon atoms in which at least a portion of the hydrogen atoms are substituted with a halogen atom or a hydroxy group; an alkoxy group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms in which at least a portion of the hydrogen atoms are substituted with at least one of the above halogen atoms and a hydroxy group; an alkenyl group having 2 to 3 carbon atoms; an acyl group having 2 to 3 carbon atoms; an alkylsilyl group having 1 to 3 carbon atoms; an alkoxysilyl group having 1 to 3 carbon atoms; a hydroxy group, and a nitrile group.

Specific examples of Ar ₁ and Ar _1′ in the diamine (0) include 1,4-phenylene, 1,3-phenylene, 2-methyl-1,4-phenylene, 2-ethyl-1,4-phenylene, 2-propyl-1,4-phenylene, 2-butyl-1,4-phenylene, 2-isopropyl-1,4-phenylene, 2-t-butyl-1,4-phenylene, 2-methoxy-1,4-phenylene, 2-ethoxy-1,4-phenylene, 2-propoxy-1,4-phenylene, 2-butoxy-1,4-phenylene, 2-fluoro-1,4-phenylene, and the like. benzene rings which may have a substituent such as 4,4'-biphenylylene, 2-methyl-4,4'-biphenylylene, 2-ethyl-4,4'-biphenylylene, 2-propyl-4,4'-biphenylylene, 2-butyl-4,4'-biphenylylene, 2,3,5,6-tetramethyl-1,4-phenylene, 4-phenylene, 2,3-dimethyl-1,4-phenylene, 4-methyl-1,3-phenylene, 5-methyl-1,3-phenylene, 4-fluoro-1,3-phenylene, 2,3,5,6-tetramethyl-1,4-phenylene, etc. -t-butyl-4,4'-biphenylylene, 2-methoxy-4,4'-biphenylylene, 2-ethoxy-4,4'-biphenylylene, 2-fluoro-4,4'-biphenylylene, 3-methyl-4,4'-biphenylylene, 3-ethyl-4,4'-biphenylylene, 3-propyl-4,4'-biphenylylene, 3-butyl-4,4'-biphenylylene, 3-t-butyl-4,4'-biphenylylene, 3-methoxy-4,4'-biphenylylene, 3-ethoxy-4,4'-biphenylylene biphenyl structures which may have a substituent, such as phenylylene, 3-fluoro-4,4'-biphenylylene, 2,2'-dimethyl-4,4'-biphenylylene, 3,3'-dimethyl-4,4'-biphenylylene, 3,3'-biphenylylene, 5-methyl-3,3'-biphenylylene, and 5,5'-dimethyl-3,3'-biphenylylene; and naphthalene rings which may have a substituent, such as 1,5-naphthylene, 2,6-naphthylene, and 1-methyl-2,6-naphthylene.

A of the diamine (0) is a divalent organic group having 1 to 10 carbon atoms and an alkylene structure. When the alkylene structure has three or more carbon-carbon bonds, any carbon-carbon bond constituting the alkylene structure may be replaced with a carbon-carbon double bond. A is preferably an alkylene group (q0) having 1 to 10 carbon atoms; a divalent organic group (q1) in which -O-, -C(=O)-, -NH-, -O-C(=O)-, -C(=O)-O-, -NR-C(=O)-, -C(=O)-NR-, or -NR- (R represents a monovalent organic group) is inserted between the carbon-carbon bonds of the alkylene group; or a divalent organic group (q2) having at least one -NR-C(=O)-NR- (R represents a hydrogen atom or a monovalent organic group) between the carbon-carbon bonds of the alkylene group.
Here, examples of the monovalent organic group for R in the above -NR-C(=O)-NR- include the structures exemplified for R in -C(=O)-NR- representing _L1 and L1 _' in the above diamine (0).

Preferred specific examples of the above (q0), (q1) and (q2) are as follows.
*-( _CH2 ) _n- *,
*-(CH ₂ ) _n1 -O-(CH ₂ ) _n2 -*,
*-(CH ₂ ) _n1 -NR-(CH ₂ ) _n2 -*,
*-(CH ₂ ) _m1 -O-C(=O)-(CH ₂ ) _n' -C(=O)-O-(CH ₂ ) _m2 -*,
*-(CH ₂ ) _m1 -C(=O)-O-(CH ₂ ) _n' -O-C(=O)-(CH ₂ ) _m2 -*,
*-(CH ₂ ) _m1 -C(=O)-NR-(CH ₂ ) _n' -NR-C(=O)-(CH ₂ ) _m2 -*,
*-(CH ₂ ) _m1 -NR-C(=O)- (CH ₂ ) _n' -C(=O)-NR-(CH ₂ ) _m2 -*,
*-(CH ₂ ) _n1 -NR-C(=O)-NR-(CH ₂ ) _n2 -*

In the above chemical formula, R represents a hydrogen atom or a monovalent organic group. Examples of the monovalent organic group include the structures exemplified for R in -C(=O)-NR- representing _L1 and L1 _' in the above diamine (0). The two R's may be the same or different.
n is an integer of 1 to 10, more preferably an integer of 2 to 10, and further preferably an integer of 2 to 6.
m1 and m2 each independently represent an integer of 0 to 4; n' represents an integer of 1 to 6; the sum of m1, m2 and n' is 1 to 8.
In the formula *-(CH ₂ ) _n1 -O-(CH ₂ ) _n2 -*, n1 and n2 each independently represent an integer of 1 to 6, and the sum of n1 and n2 is 2 to 10.
In the formula *-(CH ₂ ) _n1 -NR-C(═O)-NR-(CH ₂ ) _n2 -*, n1 and n2 each independently represent an integer of 1 to 6, and the sum of n1 and n2 is 2 to 9.

From the viewpoint of suitably obtaining the effects of the present invention, the following embodiments are preferred for *-L ₁ -A-L _1' -*. In the formula below, the definitions of m1, m2, n, n', n1, and n2 are the same as in the formula above. Furthermore, in the formula below, R represents a hydrogen atom or a monovalent organic group. When two R are present, each of them independently has the above definition. Examples of the monovalent organic group include the structures exemplified for R in -C(═O)-NR- representing L ₁ and L _1' in formula (H ₁ ) of diamine (0) above.
*-(CH ₂ ) _n -*, -O-(CH ₂ ) _n -O-*,
*-NR-(CH ₂ ) _n -NR-*,
*-O-(CH ₂ ) _n1 -O-(CH ₂ ) _n2 -O-*,
*-O-(CH ₂ ) _n1 -NR-(CH ₂ ) _n2 -O-*,
*-C(=O)-(CH ₂ ) _n -C(=O)-*,
*-C(=O)-NR-(CH ₂ ) _n -O-*,
*-O-C(=O)-(CH ₂ ) _n -O-*,
*-OC(=O)-(CH ₂ ) _n -OC(=O)-*,
*-O-C(=O)-(CH ₂ ) _n -C(=O)-O-*,
*-(CH ₂ ) _m1 -O-C(=O)-(CH ₂ ) _n' -C(=O)-O-(CH ₂ ) _m2 -*
*-S-(CH ₂ ) _n -S-*,
*-C(=O)-NR-(CH ₂ ) _n -NR-C(=O)-*,
*-C(=O)-O-(CH ₂ ) _n -O-C(=O)-*,
*-(CH ₂ ) _m1 -C(=O)-O-(CH ₂ ) _n' -O-C(=O)-(CH ₂ ) _m2 -*
*-O-(CH ₂ ) _n -*, *-S-(CH ₂ ) _n -*,
*-NR-C(=O)-(CH ₂ ) _n -C(=O)-NR-*
*-(CH ₂ ) _m1 -C(=O)-NR-(CH ₂ ) _n' -NR-C(=O)-(CH ₂ ) _m2 -*,
*-(CH ₂ ) _m1 -NR-C(=O)- (CH ₂ ) _n' -C(=O)-NR-(CH ₂ ) _m2 -*,
*-(CH ₂ ) _n1 -NR-C(=O)-NR-(CH ₂ ) _n2 -*
Furthermore, from the viewpoint of suitably obtaining the effects of the present invention, *-(CH ₂ ) _n -*, *-O-(CH ₂ ) _n -O-* and *-O-(CH ₂ ) _n -* are preferred.

The polyamic acid (A) may contain, as a structural unit derived from a diamine, at least one structural unit represented by the above formula (1D _a ), in which Y _a is a divalent organic group having three or more benzene rings.
Here, the benzene ring in the "divalent organic group having three or more benzene rings" includes a benzene ring constituting a condensed ring. When counting the number of benzene rings in the diamine (0), a naphthalene ring is counted as having two benzene rings, an anthracene ring is counted as having three benzene rings, and a biphenyl structure is counted as having two benzene rings.

From the viewpoint of suitably obtaining the effects of the present invention, the polyamic acid (A) preferably has a structural unit represented by formula (1D a ) in which at least one of Y _a is a divalent organic group derived from diamine (0) in which Ar ₁ and Ar ₁ ' have the same structure, and at least one of the other Y _a is a divalent organic group derived from diamine (0) in which Ar ₁ and Ar _{1' have} different structures.
As a preferred combination when Ar ₁ and Ar _1' are the same structure, the combination of the biphenyl structure which may have the above-mentioned substituent and the biphenyl structure which may have the above-mentioned substituent, the combination of the naphthalene ring which may have the above-mentioned substituent and the naphthalene ring which may have the above-mentioned substituent can be mentioned.Also, as a preferred combination when Ar ₁ and Ar _1' are different structures, the combination of the benzene ring which may have the above-mentioned substituent and the biphenyl structure which may have the above-mentioned substituent, the combination of the benzene ring which may have the above-mentioned substituent and the naphthalene ring which may have the above-mentioned substituent, the combination of the biphenyl structure which may have the above-mentioned substituent and the naphthalene ring which may have the above-mentioned substituent can be mentioned.

From the viewpoint of suitably achieving the effects of the present invention, the structural unit (1D-1) preferably has a divalent organic group represented by any one of the following formulas (h1-1) to (h1-22), a divalent organic group obtained by removing two amino groups from a diamine represented by the below-described formula (d _Da -1), or a divalent organic group obtained by removing two amino groups from a diamine represented by the below-described formulas (Am-1) to (Am-2).
In formulae (h1-1) to (h1-22), the bonding positions of the benzene ring are preferably the 1- and 4-positions, and the bonding positions of the naphthalene ring are preferably the 2- and 6-positions.
In formula (h1-4), the total number of —CH ₂ — groups is 10 or less.
In formulae (h1-7), (h1-8) and (h1-14), the total number of -CH ₂ - is 8 or less, and two m's may be the same or different.
In addition, the hydrogen atoms on the benzene rings in the following formulas (h1-1) to (h1-22) may be substituted with a methyl group, a methoxy group, or a fluorine atom.

（式（Ｉｍ）中、Ｘは、非環式又は脂環式テトラカルボン酸二無水物から２つの無水基を除いた４価の有機基を表す。）
　上記式（Ｉｍ）中のＸは、上記式（ｘ－１）、又は上記式（Ｘ_５ａ－１）～（Ｘ_５ａ－４）で表される４価の有機基、１，２，３，４－ブタンテトラカルボン酸二無水物から２つの無水基を除いた４価の有機基が好ましい。 (Diamine (Ph))
Ar represents a benzene ring, a biphenyl structure, a naphthalene ring, or a divalent organic group represented by the following formula (Im). Any hydrogen atom on the benzene ring, biphenyl structure, or naphthalene ring of Ar may be substituted with a monovalent group, and examples of the monovalent group include a halogen atom, an alkyl group having 1 to 3 carbon atoms, an alkyl group having 1 to 3 carbon atoms in which at least a portion of the hydrogen atoms is substituted with a halogen atom or a hydroxy group, an alkoxy group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms in which at least a portion of the hydrogen atoms is substituted with at least one of the halogen atoms and the hydroxy group, an alkenyl group having 2 to 3 carbon atoms, an acyl group having 2 to 3 carbon atoms, an alkylsilyl group having 1 to 3 carbon atoms, an alkoxysilyl group having 1 to 3 carbon atoms, a hydroxy group, and the like.

(In formula (Im), X represents a tetravalent organic group obtained by removing two anhydride groups from an acyclic or alicyclic tetracarboxylic acid dianhydride.)
X in the above formula (Im) is preferably a tetravalent organic group represented by the above formula (x-1) or any of the above formulas (X _5a -1) to (X _5a -4), or a tetravalent organic group obtained by removing two anhydride groups from 1,2,3,4-butanetetracarboxylic dianhydride.

The divalent organic group represented by the above formula (Im) is preferably a structure represented by the following formulas (Im-1) to (Im-6).

Preferred specific examples of diamine (Ph) include p-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, m-phenylenediamine, 2,4-dimethyl-m-phenylenediamine, 1,4-diamino-2,5-methoxybenzene, 2,5-diaminotoluene, 2,6-diaminotoluene, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dihydroxy-4,4'-diaminobiphenyl, 3-trifluoromethyl-4,4'-diaminobiphenyl, 2-trifluoromethyl-4,4'-diaminobiphenyl, 3-fluoro-4,4'-diaminobiphenyl, 2 ... Examples of the diaminobiphenyl include fluoro-4,4'-diaminobiphenyl, 2,2'-difluoro-4,4'-diaminobiphenyl, 3,3'-difluoro-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 3,3'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 3,4'-diaminobiphenyl, 4,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 2,2'-diaminobiphenyl, 2,3'-diaminobiphenyl, 1,5-diaminonaphthalene, 1,6-diaminonaphthalene, 1,7-diaminonaphthalene, 2,5-diaminonaphthalene, 2,6-diaminonaphthalene, 2,7-diaminonaphthalene, and diamines in which amino groups are bonded to both ends of a divalent organic group represented by the above formula (Im).

(Diamine (0)')
Diamine (0)' is a diamine represented by "HN(Z)-Ar ₂ -L ₂ -A ₂ -L _2' -Ar _2' -N(Z)-H".
Ar ₂ and Ar _2' each independently represent a benzene ring, a biphenyl structure, a naphthalene ring, or an aromatic heterocycle. Any hydrogen atom on the ring of Ar ₂ and Ar _2' may be substituted with a monovalent group. A ₂ represents a divalent organic group having an alkylene group. _{A 2} is preferably a divalent organic group having 1 to 30 carbon atoms, more preferably a divalent organic group having 1 to 20 carbon atoms, and even more preferably a divalent organic group having 1 to 18 carbon atoms.
L ₂ and L _2' each independently represent a single bond, -O-, -S-, -C(=O)-, -O-C(=O)-, -NR- (R represents a hydrogen atom or a monovalent organic group), -C(=O)-NR- (R represents a hydrogen atom or a monovalent organic group), or -NR-C(=O)- (R represents a hydrogen atom or a monovalent organic group).
However, any one of Ar ₂ , Ar _2′ and A ₂ has a heterocycle.
Examples of the heterocyclic ring include a pyrrole ring, an imidazole ring, a pyrazole ring, a triazole ring, a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring, an indole ring, a benzimidazole ring, a purine ring, a quinoline ring, an isoquinoline ring, a naphthyridine ring, a quinoxaline ring, a phthalazine ring, a triazine ring, a carbazole ring, an acridine ring, a piperidine ring, a piperazine ring, a pyrrolidine ring, a hexamethyleneimine ring, etc. Among these, a pyridine ring, a pyrimidine ring, a pyrazine ring, a benzimidazole ring, a piperidine ring, a piperazine ring, a quinoline ring, a carbazole ring, or an acridine ring is preferred.
More preferred specific examples of diamine (0)' include diamines represented by the following (d _Da -8), 4-[4-[(4-aminophenoxy)methyl]-4,5-dihydro-4-methyl-2-oxazolyl]-benzeneamine, 4-[4-[(4-aminophenoxy)methyl]-4,5-dihydro-2-oxazolyl]-benzeneamine, and diamines represented by the following (d _Ht -1) to (d _Ht -8). _{d Ht} -6 and d _Ht -8 are preferably 1,4-bis(p-aminobenzyl)piperazine and 4,4'-[4,4'-propane-1,3-diylbis(piperidine-1,4-diyl)]dianiline.

In one embodiment, the polyamic acid (A) and/or polyamic acid (B) preferably contains 5 to 100 mol % of the structural unit (1D-1) relative to 1 mole of all structural units derived from diamine contained in the polyamic acid (A) and/or polyamic acid (B), more preferably 5 to 95 mol %, even more preferably 10 to 95 mol %, and even more preferably 20 to 80 mol %.

Examples of the other diamine in the structural unit (1D-2) derived from the other diamine include the following.
4-aminobenzylamine, 2-(4-aminophenyl)ethylamine, semi-aromatic diamines having a secondary amino group and a primary amino group (preferably 4-(2-(methylamino)ethyl)aniline) (herein, the semi-aromatic diamine refers to a diamine in which one amino group is bonded to an aromatic ring and the other amino group is not bonded to an aromatic ring), 4-(2-aminoethyl)aniline, 2-(6-aminonaphthyl)ethylamine, and other specific diamines (hereinafter, these are also referred to as specific diamines (1));

1,4-phenylenebis(4-aminobenzoate), 1,4-phenylenebis(3-aminobenzoate), 1,3-phenylenebis(4-aminobenzoate), 1,3-phenylenebis(3-aminobenzoate), bis(4-aminophenyl)terephthalate, bis(3-aminophenyl)terephthalate, bis(4-aminophenyl)isophthalate, bis(3-aminophenyl)isophthalate; 4,4'-diaminoazobenzene, diaminotrans, Diamines represented by the formulae (D-1) to (D-5), 4,4-diaminochalcones, or [4-[(E)-3-[2-(2,4-diaminophenyl)ethoxy]-3-oxo-prop-1-enyl]phenyl]4-(4,4,4-trifluorobutoxy)benzoate, or [4-[(E)-3-[[5-amino-2-[4-amino-2-[[(E)-3-[4-[4-(4,4,4-trifluorobutoxy)benzoyl]oxyphenyl]prop-2-enoyl]o diamines having a photoalignment group, such as aromatic diamines having a cinnamate structure, typified by 4-(4,4,4-trifluorobutoxy)benzoate; diamines having a photopolymerizable group at the terminal, such as 2-(2,4-diaminophenoxy)ethyl methacrylate or 2,4-diamino-N,N-diallylaniline; 1-(4-(2-(2,4-diaminophenoxy)ethoxy)phenyl diamines having a radical polymerization initiator function, such as 2-(4-(2-hydroxy-2-methylpropanoyl)phenoxy)ethyl-3,5-diaminobenzoate; diamines having an amide bond, such as 4,4'-diaminobenzanilide, diamines represented by the following formula (D-6), and diamines represented by the following formulas (Am-3) to (Am-6); diamines having a urea bond, such as 1,3-bis(4-aminophenyl)urea; diamines having a thermally detachable group, such as H ₂ N-Y _D -NH ₂ (Y _D represents a divalent organic group having -N(D)- (D represents a protecting group which is detached by heating and replaced with a hydrogen atom) in the molecule);

　3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-bis(4-aminophenoxy)diphenyl ether, 1,4-bis[4-(4-aminophenoxy)phenoxy]benzene, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 4,4'-sulfonyldianiline, 3,3'-sulfonyldianiline, bis(4-aminophenyl)silane, bis(3-aminophenyl)silane, dimethyl-bis(4-aminophenyl)silane, dimethyl-bis(3-aminophenyl)silane, 4,4'-thiodiazide dianiline, 3,3'-thiodianiline, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 2,2'-bis[4-(4-aminophenoxy)phenyl]propane, 2,2'-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2'-bis(4-aminophenyl)hexafluoropropane, 2,2'-bis(3-aminophenyl)hexafluoropropane, 2,2'-bis(3-amino-4-methylphenyl)hexafluoropropane, 2,2'-bis(4-aminophenyl)propane, 2,2'-bis(3-aminophenyl)propane, 2,2'-bis(3-amino-4-methylphenyl)propane, 4,4'-diaminobenzophenone, 1,4-bis(4-aminobenzyl)benzene; 2,6-diaminopyridine, 3,4-diaminopyridine azine, 2,4-diaminopyrimidine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, 1,4-bis-(4-aminophenyl)-piperazine, 3,6-diaminoacridine, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N-(3-(1H-imidazol-1-yl)propyl-3,5-diaminobenzamide, 2,5-bis (4-aminophenyl)pyrrole, 4,4'-(1-methyl-1H-pyrrole-2,5-diyl)bis[benzenamine], 1,4-bis-(4-aminophenyl)-piperazine, 2-N-(4-aminophenyl)pyridine-2,5-diamine, 2-N-(5-aminopyridin-2-yl)pyridine-2,5-diamine, 2-(4-aminophenyl)-5-aminobenzimidazole, 2-(4-aminophenyl)-5-aminobenzimidazole, heterocycle-containing diamines such as N,N'-bis(4-phenyl)-6-aminobenzimidazole, 5-(1H-benzimidazol-2-yl)benzene-1,3-diamine, or diamines represented by the following formulae (z-1) to (z-22), or diamines having a diphenylamine structure such as 4,4'-diaminodiphenylamine, 4,4'-diaminodiphenyl-N-methylamine, N,N'-bis(4-aminophenyl)-benzidine, N,N'-bis(4-aminophenyl)-N,N'-dimethylbenzidine, or N,N'-bis(4-aminophenyl)-N,N'-dimethyl-1,4-benzenediamine, excluding amino groups derived from -N(D)- (D represents a protecting group which is eliminated by heating and replaced with a hydrogen atom). Hereinafter, this is also referred to as a specific nitrogen atom-containing structure. However, the specific nitrogen atom-containing structure is an atomic group other than the two amino groups involved in the polycondensation reaction.) Diamines having;

　2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6-diaminoresorcinol, 4,4'-diamino-3,3'-dihydroxybiphenyl; 2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, 3,5-diaminobenzoic acid, 4,4'-diaminobiphenyl-3-carboxylic acid, 4,4'-diaminodiphenylmethane-3-carboxylic acid, 4,4'-diaminodiphenylethane-3-carboxylic acid, 4,4'-diaminobiphenyl-3,3'-dica diamines having a carboxy group such as carboxylic acid, 4,4'-diaminobiphenyl-2,2'-dicarboxylic acid, 3,3'-diaminobiphenyl-4,4'-dicarboxylic acid, 3,3'-diaminobiphenyl-2,4'-dicarboxylic acid, 4,4'-diaminodiphenylmethane-3,3'-dicarboxylic acid, 4,4'-diaminodiphenylethane-3,3'-dicarboxylic acid, and 4,4'-diaminodiphenylether-3,3'-dicarboxylic acid; 1-(4-aminophenyl)-1,3,3-trimethyl-1H-indan-5-amine, ... )-2,3-dihydro-1,3,3-trimethyl-1H-inden-6-amine; diamines having a steroid skeleton such as cholestanyloxy-3,5-diaminobenzene, cholestanyloxy-3,5-diaminobenzene, cholestanyloxy-2,4-diaminobenzene, cholestanyl 3,5-diaminobenzoate, cholestanyl 3,5-diaminobenzoate, lanostannyl 3,5-diaminobenzoate, and 3,6-bis(4-aminobenzoyloxy)cholestane; diamines represented by the following formulae (V-1) to (V-2); Diamines having a siloxane bond such as metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, and other acyclic aliphatic diamines; alicyclic diamines such as 1,3-bis(aminomethyl)cyclohexane, 1,4-diaminocyclohexane, and 4,4'-methylenebis(cyclohexylamine); and diamines in which two amino groups are bonded to a group represented by any one of formulas (Y-1) to (Y-167) described in WO2018/117239.

（（ｚ－１３）におけるＸ_１３は、メチル基、又はフェニル基を表す。）

（式（ｚ－１９）中、Ｘ_１９は、－Ｃ（＝Ｏ）－、－Ｏ－、又は－ＮＨ－を表す。Ｒ_１９、Ｒ_１９’は、それぞれ独立して、水素原子又はメチル基を表す。
式（ｚ－２２）中、Ｘ_２２は、－ＣＨ_２－、－（ＣＨ_２）_３－、又は－ＮＨ－を表す。）

(X ₁₃ in (z-13) represents a methyl group or a phenyl group.)

In formula (z-19), X ₁₉ represents —C(═O)—, —O—, or —NH—. R ₁₉ and R _19′ each independently represent a hydrogen atom or a methyl group.
In formula (z-22), X ₂₂ represents —CH ₂ —, —(CH ₂ ) ₃ —, or —NH—.

（式（Ｖ－１）中、ｍ、ｎは０～３の整数（但し、１≦ｍ＋ｎ≦４を満たす。）であり、ｊは０又は１の整数であり、Ｘ^１は、－（ＣＨ_２）_ａ－（ａは１～１５の整数である。）、－ＣＯＮＨ－、－ＮＨＣＯ－、－ＣＯ－Ｎ（ＣＨ_３）－、－ＮＨ－、－Ｏ－、－ＣＨ_２Ｏ－、－ＣＨ_２－ＯＣＯ－、－ＣＯＯ－、又は－ＯＣＯ－を表す。Ｒ^１は、フッ素原子、炭素数１～１０のフッ素原子含有アルキル基、炭素数１～１０のフッ素原子含有アルコキシ基、炭素数３～１０のアルキル基、炭素数３～１０のアルコキシ基、又は炭素数３～１０のアルコキシアルキル基を表す。式（Ｖ－２）中、Ｘ^２は－Ｏ－、－ＣＨ_２Ｏ－、－ＣＨ_２－ＯＣＯ－、－ＣＯＯ－、又は－ＯＣＯ－を表す。式（ｚ－２）、（Ｖ－１）、（Ｖ－２）において、ｍ、ｎ、Ｘ^１、Ｒ^１が２つ存在する場合、それぞれ独立して、上記定義を有する。）

In formula (V-1), m and n are integers of 0 to 3 (with the proviso that 1≦m+n≦4 is satisfied), j is an integer of 0 or 1, and X ¹ represents -(CH ₂ ) _a - (a is an integer of 1 to 15), -CONH-, -NHCO-, -CO-N(CH ₃ )-, -NH-, -O-, -CH ₂ O-, -CH ₂ -OCO-, -COO-, or -OCO-. ^{R 1} represents a fluorine atom, a fluorine atom-containing alkyl group having 1 to 10 carbon atoms, a fluorine atom-containing alkoxy group having 1 to 10 carbon atoms, an alkyl group having 3 to 10 carbon atoms, an alkoxy group having 3 to 10 carbon atoms, or an alkoxyalkyl group having 3 to 10 carbon atoms. In formula (V-2), X ² represents -O-, -CH ₂ O-, -CH ₂ In formulae (z-2), (V-1) and (V-2), when there are two m, n, X ¹ and R ¹ , each independently has the above definition.

In addition, D in -N(D)- of the other diamines described above is preferably a carbamate-based organic group such as a benzyloxycarbonyl group, a 9-fluorenylmethyloxycarbonyl group, an allyloxycarbonyl group, or a Boc group. The Boc group is particularly preferred from the viewpoints that it is efficiently eliminated by heat, is eliminated at a relatively low temperature, and is discharged as a harmless gas upon elimination.

（式（ｄ_Ｄａ－２）、（ｄ_Ｄａ－６）、（ｄ_Ｄａ－７）中、Ｒは水素原子又はＢｏｃ基を表す。）

Preferred examples of the diamine having a thermally detachable group exemplified as the other diamines above include diamines selected from the following formulae (d _Da -1) to (d _Da -10), with diamines selected from the following formulae (d _Da -2) to (d _Da -7) and (d _Da -9) to (d _Da -10) being more preferred. (However, in (d _Da -3) to (d _Da -5), the total number of carbon atoms in the linking groups linking the benzene rings is 11 or more.)

(In formulas (d _Da -2), (d _Da -6), and (d _Da -7), R represents a hydrogen atom or a Boc group.)

In one embodiment, when the polyamic acid (A) and/or the polyamic acid (B) used in the present invention has the above structural unit (1D-2), it is more preferable for it to contain a structural unit derived from the above specific diamine (1), from the viewpoint of suitably obtaining the effects of the present invention.
The content of the structural units derived from the specific diamine (1) is preferably 5 to 95 mol %, more preferably 5 to 90 mol %, and even more preferably 20 to 80 mol %, based on 1 mol of all the structural units derived from diamines contained in the polyamic acid (A) and/or the polyamic acid (B).
From the viewpoint of enhancing the two-layer separation between two types of polymers, the polyamic acid (A) and/or the polyamic acid (B) may contain, as the structural unit (1D-2), a structural unit derived from a diamine having a thermally detachable group. The structural unit derived from a diamine having a thermally detachable group is preferably 5 to 40 mol %, more preferably 5 to 35 mol %, and even more preferably 5 to 30 mol %, relative to 1 mol of all structural units derived from diamines contained in the polyamic acid (A) and/or the polyamic acid (B).
Furthermore, from the viewpoint of suitably obtaining the effects of the present invention, it is preferable that the polyamic acid (A) and/or the polyamic acid (B) is a structural unit derived from a diamine other than the diamine having the thermally detachable group as the structural unit (1D-2), the diamine having no side chain group having 3 or more carbon atoms.
Here, examples of diamines having a side chain group with 3 or more carbon atoms include diamines having the above-mentioned photoalignment group having a side chain group with 3 or more carbon atoms, diamines having the above-mentioned photopolymerizable group at an end and having a side chain group with 3 or more carbon atoms, diamines having the above-mentioned radical polymerization initiator function and having a side chain group with 3 or more carbon atoms, diamines having the above-mentioned specific nitrogen atom-containing structure and having a side chain group with 3 or more carbon atoms, diamines having the above-mentioned steroid skeleton, diamines represented by the above formulas (V-1) to (V-2) and the like having a side chain group with 3 or more carbon atoms, etc.

In terms of reducing residual images derived from residual DC, it is preferable that the polyamic acid (A) and _/ or the polyamic acid ( _B ) have a divalent organic group obtained by removing two amino groups from a diamine having a urea bond (for example, a diamine (0) in which A is a divalent organic group (q2), or a diamine having a urea bond exemplified in the above other diamines), the diamine having an amide bond, the diamine (Ph), the diamine (0)', the diamine having the specific nitrogen atom-containing structure, the diamine having a carboxy group, 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, p-phenylenediamine, and m-phenylenediamine (these are also collectively referred to as "specific divalent organic group (b)").

From the viewpoint of reducing afterimages derived from residual DC, the polyamic acid (A) and/or the polyamic acid (B) may contain structural units (b-1Db) represented by formula (1D _b ) in which the above Y _a and/or Y _b are the above specific divalent organic group (b), in an amount of 5 mol % or more, preferably 10 mol % or more, and more preferably 20 mol % or more, relative to 1 mol of the total structural units derived from diamine contained in the polyamic acid (A) and/or the polyamic acid (B).
In addition, from the viewpoint of suitably obtaining the effects of the present invention, it is preferable that the polyamic acid (A) and/or the polyamic acid (B) is a structural unit derived from a diamine other than the diamine having the thermally detachable group, and the other diamine is a structural unit derived from a diamine having no side chain group having 3 or more carbon atoms, as the structural unit (b-1Db).

Examples of the monovalent organic group for Z in the above formula (1D _b ) include the structures exemplified for Z in the above formula (1D _a ).

One embodiment of the liquid crystal aligning agent of the present invention includes the following embodiments (BL1) to (BL2), but is not limited thereto.
Aspect (BL1): An aspect in which the polyamic acid (A) contains the structural unit (1D-1) in an amount of 5 to 95 mol % relative to 1 mol of all structural units derived from diamine contained in the polyamic acid (A), and the polyamic acid (B) contains the specific divalent organic group (b) in an amount of 10 mol % or more relative to 1 mol of all structural units derived from diamine contained in the polyamic acid (B).
Aspect (BL2): In one aspect of the liquid crystal aligning agent of the present invention, the polyamic acid (A) contains the above structural unit (1D-1) in an amount of 5 to 95 mol % relative to 1 mol of all structural units derived from diamines contained in the polyamic acid (A),
The polyamic acid (B) contains the specific divalent organic group (b) in an amount of 10 to 95 mol % relative to 1 mol of all structural units derived from diamine contained in the polyamic acid (B), and contains the structural units (1D-1) excluding the specific divalent organic group (b) in an amount of 5 to 90 mol % relative to 1 mol of all structural units derived from diamine contained in the polyamic acid (B).

In the liquid crystal aligning agent of the present invention, from the viewpoint of the effects of the present invention, particularly less residual image caused by residual DC, the content ratio of polyamic acid (A) and polyamic acid (B) in terms of the mass ratio of [polyamic acid (A)/polyamic acid (B)] may be 10/90 to 90/10, 20/80 to 90/10, or 20/80 to 80/20.

<Production of Polyamic Acid>
The polyamic acid contained in the liquid crystal aligning agent of the present invention can be produced, for example, by the following method.
A polymer having an amic acid structure (polyamic acid) is obtained by reacting a tetracarboxylic dianhydride component, a diamine component, and an amino terminal modifier added as necessary. When the polyamic acid has a structure represented by the above formula (1D _a ), for example, a diamine having a structure of -N(Z)-Y _a -N(Z)- (Y _a and Z are defined as above) is used as the diamine component, and a tetracarboxylic dianhydride having X _a (X _a is defined as above) is used as the tetracarboxylic acid derivative component.

The ratio of the tetracarboxylic dianhydride and diamine used in the production of polyamic acid is preferably 0.5 to 2 equivalents, more preferably 0.8 to 1.2 equivalents, of the acid anhydride group of the tetracarboxylic dianhydride relative to 1 equivalent of the amino group of the diamine. As in the case of a normal polycondensation reaction, the closer the equivalent of the acid anhydride group of the tetracarboxylic dianhydride is to 1 equivalent, the higher the molecular weight of the polyamic acid produced.
The reaction temperature in the production of the polyamic acid is preferably −20 to 150° C., more preferably 0 to 100° C. The reaction time is preferably 0.1 to 24 hours, more preferably 0.5 to 12 hours.
The polyamic acid can be produced at any concentration, preferably 1 to 50% by mass, more preferably 5 to 30% by mass. The reaction can be carried out at a high concentration in the early stage of the reaction, and then a solvent can be added.

At least a part of the terminals of the polyamic acid (A) contains the non-amino group. At least a part of the terminals of the polyamic acid (B) may contain the non-amino group. The non-amino group can be formed, for example, by using an amino terminal modifier.
Preferred specific examples of the amino terminal modifier include the above-mentioned acyclic aliphatic dicarboxylic acid anhydrides, the compound (e2-1), the compound (e2-2), and the active ester compound (e3).
The polyamic acid (A) and/or polyamic acid (B) can be obtained, for example, by the following production method (a), production method (b), or a method using both of them.
Production method (a): A method of polymerizing (polycondensing) a tetracarboxylic dianhydride component, a diamine component, and an amino terminal modifier.
Production method (b): A method in which a tetracarboxylic dianhydride component is reacted with a diamine component to obtain a polymer solution containing a polyamic acid having unmodified amino terminals, and then an amino terminal modifier is added to the polymer solution to react the terminals of the polymer.
In the above-mentioned Production Method (b), in order to obtain a polyamic acid having an amino terminal, the ratio of the diamine to the tetracarboxylic dianhydride used in the production of the polyamic acid may be equal to or greater than the ratio of the tetracarboxylic dianhydride, and the amount of the acid anhydride group of the tetracarboxylic dianhydride is preferably 0.5 to 1.0 equivalent, more preferably 0.8 to 1.0 equivalent, per equivalent of the amino group of the diamine.
The proportion of the amino terminal modifier used is preferably 40 parts by mol or less, and more preferably 30 parts by mol or less, per 100 parts by mol of the total of the diamine components used.
The proportion of the amino terminal modifier used is preferably 0.1 part by mol or more, and more preferably 0.2 part by mol or more, per 100 parts by mol of the total of the diamine components used.
The temperature when reacting the polyamic acid with the amino terminal modifier may be the same as the reaction temperature in the production of the polyamic acid, or the reaction may be carried out while heating. The heating temperature is preferably 30 to 80° C., more preferably 30 to 60° C. The reaction time is preferably 0.1 to 24 hours, more preferably 1 to 24 hours.

Specific examples of organic solvents used in the production of the polyamic acid include cyclohexanone, cyclopentanone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide, and 1,3-dimethyl-2-imidazolidinone. In addition, when the polyamic acid to be produced has high solvent solubility, solvents such as methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, diethylene glycol monomethyl ether, and diethylene glycol monoethyl ether can be used.

<Solution viscosity and molecular weight of polyamic acid>
The polyamic acid used in the present invention preferably has a solution viscosity of, for example, 10 to 1000 mPa·s when the polyamic acid is made into a solution having a concentration of 10 to 15% by mass from the viewpoint of workability. The solution viscosity (mPa·s) of the polymer is a value measured at 25° C. using an E-type rotational viscometer for a polymer solution having a concentration of 10 to 15% by mass prepared using a good solvent for the polymer (e.g., γ-butyrolactone, N-methyl-2-pyrrolidone, etc.).
The polyamic acid has a polystyrene-equivalent weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) of preferably 1,000 to 500,000, more preferably 2,000 to 300,000. The molecular weight distribution (Mw/Mn), which is expressed as the ratio of Mw to the polystyrene-equivalent number average molecular weight (Mn) measured by GPC, is preferably 15 or less, more preferably 10 or less. With the molecular weight in this range, good alignment and stability of the liquid crystal display element can be ensured.

The liquid crystal alignment agent of the present invention may contain other polymers other than the polymer (A) and the polymer (B). Specific examples of the other polymers include at least one polymer (Q) selected from the group consisting of polyimide precursors other than the polymer (A) and the polymer (B) and polyimides which are imidized products of the polyimide precursors, polysiloxanes, polyesters, polyamides, polyureas, polyorganosiloxanes, cellulose derivatives, polyacetals, polystyrene derivatives, poly(styrene-maleic anhydride) copolymers, poly(isobutylene-maleic anhydride) copolymers, poly(vinyl ether-maleic anhydride) copolymers, poly(styrene-phenylmaleimide) derivatives, and polymers selected from the group consisting of poly(meth)acrylates. Specific examples of poly(styrene-maleic anhydride) copolymers include SMA1000, SMA2000, SMA3000 (manufactured by Cray Valley Corporation) and GSM301 (manufactured by Gifu Ceramics Manufacturing Co., Ltd.). Specific examples of poly(isobutylene-maleic anhydride) copolymers include ISOBAM-600 (manufactured by Kuraray Co., Ltd.). Specific examples of poly(vinyl ether-maleic anhydride) copolymers include Gantrez AN-139 (methyl vinyl ether maleic anhydride resin, manufactured by Ashland Corporation).
The other polymers may be used alone or in combination of two or more. The content ratio of the other polymers is preferably 10 to 90 parts by mass, more preferably 20 to 80 parts by mass, based on 100 parts by mass of the polymer component contained in the liquid crystal alignment agent.
In this specification, the polymer component is a general term for the polymer (A), the polymer (B), and other polymers other than these polymers contained in the liquid crystal alignment agent. When the polymers contained in the liquid crystal alignment agent are only the polymer (A) and the polymer (B), the polymer component refers to the polymer (A) and the polymer (B).

（式中Ｘ_ａは、下記式（ｘ－１）で表される４価の有機基を表す。式（１Ｄ_ａ）中、Ｙ_ａはジアミン由来の２価の有機基を表す。Ｚはそれぞれ独立して、水素原子又は１価の有機基を表す。）

（式（ｘ－１）中、Ｒ_１～Ｒ_４はそれぞれ独立して、水素原子、ハロゲン原子、炭素数１～６のアルキル基、炭素数２～６のアルケニル基、炭素数２～６のアルキニル基、フッ素原子を含有する炭素数１～６の１価の有機基、炭素数１～６のアルコキシ基、炭素数２～６のアルコキシアルキル基、炭素数２～６のアルキルオキシカルボニル基、又はフェニル基を表し、Ｒ_１～Ｒ_４の少なくとも一つは上記定義中の水素原子以外の基を表す。＊は結合手を表す。）

（式中Ｘ_ｂは、芳香族テトラカルボン酸二無水物由来の４価の有機基、下記式（ｘ－２）で表される４価の有機基、又は５員環以上の脂環構造を有する４価の有機基（Ｔ_５ａ）を表す。式（１Ｄ_ｂ）中、Ｙ_ｂはジアミン由来の２価の有機基を表す。Ｚは上記式（１Ｄ_ａ）のＺと同義である。）

（式（Ｅ）中、Ｑは、下記の基（ｅ１）～（ｅ３）のいずれかから選ばれる１価の有機基である。＊は結合手を表す。）
　（ｅ１）炭素数１～６の非環式炭化水素基
　（ｅ２）カルボキシ基を１～２つ有し、且つ、炭素数が２～３０の１価の有機基（但し、該１価の有機基は酸無水基を含まない。）
　（ｅ３）Ｂｏｃを２つ以上有し、且つ、Ｂｏｃを除く炭素数が１～３０の１価の有機基であって、上記１価の有機基は、＊１－ＮＨ（Ｂｏｃ）、＊１－Ｎ（Ｂｏｃ）_２、及び「＊１－Ｎ（Ｂｏｃ）－＊１」（＊１は、炭素原子に結合する結合手を表す。）からなる群から選ばれる保護アミノ部位を有する。なお、保護アミノ部位が２つ以上である場合、各保護アミノ部位は同一であっても良く、異なっていても良い。
［式１］
　Δ＝｜Δｂ－Δａ｜
　Δ：室温４８時間保管による回転角度の変化量
　Δａ：液晶セルの回転角度
　Δｂ：室温で４８時間放置した同液晶配向剤を使用した液晶セルの回転角度
（上記式１で、回転角度は、
　２枚の液晶配向膜付き基板を一組とし、１枚の基板上にシール剤を塗布し、もう１枚の基板を、液晶配向膜面が向き合い配向方向が０°になるようにして張り合わせた後、シール剤を硬化させ、液晶を注入し、注入口を封止して得た液晶セルに対し、
　照度１５０００ｎｉｔのバックライト点灯下、周波数６０Ｈｚで±７Ｖの交流電圧を１２０時間印加した後、液晶セルの画素電極と対向電極との間をショートさせた状態にし、室温に一日放置し、
　該液晶セルに関して、電圧無印加状態における、画素の第１領域の液晶の配向方向と第２領域の液晶の配向方向とのずれを算出して得た値である。） Another embodiment of the present invention includes the following liquid crystal aligning agent.
A liquid crystal aligning agent comprising the following polymer (A) and polymer (B), which gives a liquid crystal alignment film having a change in rotation angle represented by the following formula 1 of less than 0.2°.
Polymer (A): A polyamic acid (A) having a structural unit derived from a tetracarboxylic acid derivative and a structural unit derived from a diamine,
The structural unit (a-1Ta) represented by the following formula (1T _a ) is contained as a structural unit derived from a tetracarboxylic acid derivative,
The diamine-derived structural unit includes a structural unit (a-1Da) represented by the following formula (1D _a ):
The polyamic acid (A), wherein at least a portion of the terminals of the polyamic acid (A) contain a non-amino group, and the non-amino group is a functional group represented by the following structural formula (E):
Polymer (B): A polyamic acid (B) having a structural unit derived from a tetracarboxylic acid derivative and a structural unit derived from a diamine,
The structural unit (b-1Tb) represented by the following formula (1T _b ) is contained as a structural unit derived from a tetracarboxylic acid derivative,
The above polyamic acid, which contains a structural unit (b-1Db) represented by the following formula (1D _b ) as a structural unit derived from a diamine:

(In the formula, _Xa represents a tetravalent organic group represented by the following formula (x-1). In formula ( _1Da ), _Ya represents a divalent organic group derived from a diamine. Each Z independently represents a hydrogen atom or a monovalent organic group.)

(In formula (x-1), R ₁ to R ₄ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, a monovalent organic group having 1 to 6 carbon atoms containing a fluorine atom, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 6 carbon atoms, an alkyloxycarbonyl group having 2 to 6 carbon atoms, or a phenyl group, and at least one of R ₁ to R ₄ represents a group other than a hydrogen atom as defined above. * represents a bond.)

(In the formula, _Xb represents a tetravalent organic group derived from an aromatic tetracarboxylic dianhydride, a tetravalent organic group represented by the following formula (x-2), or a tetravalent organic group ( _T5a ) having an alicyclic structure having five or more members. In formula ( _1Db ), _Yb represents a divalent organic group derived from a diamine. Z has the same meaning as Z in formula ( _1Da ).)

(In formula (E), Q is a monovalent organic group selected from the following groups (e1) to (e3). * represents a bond.)
(e1) an acyclic hydrocarbon group having 1 to 6 carbon atoms; (e2) a monovalent organic group having 1 to 2 carboxy groups and 2 to 30 carbon atoms (however, the monovalent organic group does not include an acid anhydride group).
(e3) A monovalent organic group having two or more Boc groups and having 1 to 30 carbon atoms excluding Boc, the monovalent organic group having a protected amino moiety selected from the group consisting of *1-NH(Boc), *1-N(Boc) ₂ and *1-N(Boc)-*1 (*1 represents a bond bonded to a carbon atom). When there are two or more protected amino moieties, the protected amino moieties may be the same or different.
[Formula 1]
Δ=|Δb−Δa|
Δ: change in rotation angle due to storage at room temperature for 48 hours Δa: rotation angle of liquid crystal cell Δb: rotation angle of liquid crystal cell using the same liquid crystal alignment agent left at room temperature for 48 hours (in the above formula 1, the rotation angle is
Two substrates with liquid crystal alignment films are used as a set. A sealant is applied onto one substrate, and the other substrate is attached so that the liquid crystal alignment film faces each other and the alignment direction is 0°. The sealant is then hardened, liquid crystal is injected, and the injection port is sealed to obtain a liquid crystal cell.
Under the illumination of a backlight of 15,000 nits, an AC voltage of ±7 V at a frequency of 60 Hz was applied for 120 hours, and then the pixel electrode and the counter electrode of the liquid crystal cell were shorted and left at room temperature for one day.
This is a value obtained by calculating the difference between the alignment direction of the liquid crystal in the first region of the pixel and the alignment direction of the liquid crystal in the second region of the pixel when no voltage is applied to the liquid crystal cell.

The amount of change in the rotation angle represented by the above formula 1 is preferably 0.12° or less, and more preferably less than 0.12°.
The change in the rotation angle of the liquid crystal cell using the liquid crystal alignment agent according to another embodiment of the present invention was less than 0.2°, and the deterioration of the liquid crystal alignment property due to being left at room temperature was suppressed.
The meanings of the symbols in the liquid crystal aligning agent according to another embodiment of the present invention are the same as those of the above-mentioned liquid crystal aligning agent, including preferred embodiments.

<Liquid crystal alignment agent>
The liquid crystal aligning agent of the present invention is used for preparing a liquid crystal alignment film, and takes the form of a coating liquid from the viewpoint of forming a uniform thin film. The liquid crystal aligning agent of the present invention is also preferably a coating liquid containing the above-mentioned polymer component and a solvent.
The content (concentration) of the polymer component contained in the liquid crystal alignment agent of the present invention can be appropriately changed depending on the setting of the thickness of the coating film to be formed, but from the viewpoint of forming a uniform and defect-free coating film, it is preferably 1 mass % or more relative to the total amount of the liquid crystal alignment agent, and from the viewpoint of storage stability of the solution, it is preferably 10 mass % or less.
From the viewpoint of suitably obtaining the effects of the present disclosure, the total content ratio of the polymer (A) and the polymer (B) in the liquid crystal alignment agent is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, and even more preferably 50 parts by mass or more, relative to 100 parts by mass of the total of the polymers contained in the liquid crystal alignment agent. When the liquid crystal alignment agent contains other polymers, the content ratio of the polymer (A) and the polymer (B) is preferably 10 to 90 parts by mass, more preferably 20 to 80 parts by mass, relative to 100 parts by mass of the polymer components contained in the liquid crystal alignment agent.

The solvent contained in the liquid crystal alignment agent is not particularly limited as long as it dissolves the polymer components uniformly. Specific examples include N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethyllactamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethylsulfoxide, γ-butyrolactone, γ-valerolactone, 1,3-dimethyl-2-imidazolidinone, methyl ethyl ketone, cyclohexanone, cyclopentanone, 3-methoxy-N,N-dimethylpropanamide, and 3-butoxy-N,N-dimethylpropanamide. , N-(n-propyl)-2-pyrrolidone, N-isopropyl-2-pyrrolidone, N-(n-butyl)-2-pyrrolidone, N-(tert-butyl)-2-pyrrolidone, N-(n-pentyl)-2-pyrrolidone, N-(3-methoxypropyl)-2-pyrrolidone, N-(2-ethoxyethyl)-2-pyrrolidone, N-(4-methoxybutyl)-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone (collectively referred to as "good solvents"). Among these, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 3-methoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide, or γ-butyrolactone is preferred. The content of the good solvent is preferably 20 to 99% by mass, more preferably 20 to 90% by mass, and particularly preferably 30 to 80% by mass, of the total solvent contained in the liquid crystal alignment agent.

The solvent contained in the liquid crystal alignment agent is preferably a mixed solvent that uses, in addition to the above solvent, a solvent (also called a poor solvent) that improves the coatability when applying the liquid crystal alignment agent and the surface smoothness of the coating film. Specific examples of poor solvents to be used in combination are listed below, but are not limited to these.

For example, diisopropyl ether, diisobutyl ether, diisobutyl carbinol (2,6-dimethyl-4-heptanol), ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, 4-hydroxy-4-methyl-2-pentanone, diethylene glycol methyl ethyl ether, diethylene glycol dibutyl ether, 3-ethoxybutyl acetate, 1-methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, ethylene glycol monoacetate, ethylene glycol diacetate, propylene carbonate, ethylene carbonate, ethylene glycol monobutyl ether, ethylene glycol monoisoamyl ether, ethylene glycol monohexyl ether, propylene glycol monobutyl ether, 1-(2-butoxyethoxy)-2-propano Examples of the ethyl acetate include 2-(2-butoxyethoxy)-1-propanol, propylene glycol monomethyl ether acetate, propylene glycol diacetate, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, 2-(2-ethoxyethoxy)ethyl acetate, diethylene glycol diacetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, butyl 3-methoxypropionate, n-butyl lactate, isoamyl lactate, diethylene glycol monoethyl ether, and diisobutyl ketone (2,6-dimethyl-4-heptanone). The content of the poor solvent is preferably 1 to 80% by mass, more preferably 10 to 80% by mass, and particularly preferably 20 to 70% by mass, of the total solvent contained in the liquid crystal alignment agent. The type and content of the poor solvent are appropriately selected depending on the coating device, coating conditions, coating environment, etc. of the liquid crystal alignment agent.

Among these, diisobutyl carbinol, propylene glycol monobutyl ether, propylene glycol diacetate, diethylene glycol diethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monobutyl ether, ethylene glycol monobutyl ether acetate, and diisobutyl ketone are preferred.

Preferred solvent combinations of good and poor solvents include N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone and propylene glycol monobutyl ether, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone, 4-hydroxy-4-methyl-2-pentanone and diethylene glycol diethyl ether, and N-methyl-2-pyrrolidone and γ Examples include N-methyl-2-pyrrolidone, γ-butyrolactone, propylene glycol monobutyl ether, and diisobutyl ketone, N-methyl-2-pyrrolidone, γ-butyrolactone, propylene glycol monobutyl ether, and diisopropyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone, propylene glycol monobutyl ether, and diisobutyl carbinol, N-methyl-2-pyrrolidone, γ-butyrolactone, and dipropylene glycol dimethyl ether, and N-methyl-2-pyrrolidone, propylene glycol monobutyl ether, and dipropylene glycol dimethyl ether.

The liquid crystal alignment agent of the present invention may additionally contain components other than the polymer component and the solvent (hereinafter also referred to as additive components). Such additive components include compounds for increasing the strength of the liquid crystal alignment film (hereinafter also referred to as cross-linking compounds), adhesion aids for increasing the adhesion between the liquid crystal alignment film and the substrate or between the liquid crystal alignment film and the sealant, dielectrics or conductive substances for adjusting the dielectric constant or electrical resistance of the liquid crystal alignment film, and imidization promoters for promoting imidization.

　ヒドロキシ基及び／又はアルコキシ基を有する化合物として、Ｎ，Ｎ，Ｎ’，Ｎ’－テトラキス（２－ヒドロキシエチル）アジポアミド、下記式（ｐＬ－１）～（ｐＬ－４）で表される化合物、２，２－ビス（４－ヒドロキシ－３，５－ジヒドロキシメチルフェニル）プロパン、２，２－ビス（４－ヒドロキシ－３，５－ジメトキシフェニル）プロパン、２，２－ビス（４－ヒドロキシ－３，５－ジヒドロキシメチルフェニル）－１，１，１，３，３，３－ヘキサフルオロプロパン、ＷＯ２０１５／０７２５５４号公報や、日本特開２０１６－１１８７５３号公報の段落［００５８］に記載の化合物、日本特開２０１６－２００７９８号公報に記載の化合物、ＷＯ２０１０／０７４２６９号公報に記載の化合物等；

　重合性不飽和基を有する架橋性化合物として、グリセリンモノ（メタ）アクリレート、グリセリンジ（メタ）アクリレート（１，２－，１，３－体混合物）、グリセリントリス（メタ）アクリレート、グリセロール１，３－ジグリセロラートジ（メタ）アクリレート、ペンタエリストールトリ（メタ）アクリレート、ジエチレングリコールモノ（メタ）アクリレート、トリエチレングリコールモノ（メタ）アクリレート、テトラエチレングリコールモノ（メタ）アクリレート、ペンタエチレングリコールモノ（メタ）アクリレート、ヘキサエチレングリコールモノ（メタ）アクリレート等。 Examples of the crosslinkable compound include at least one crosslinkable compound selected from the group consisting of a crosslinkable compound (c-1) having at least one substituent selected from an epoxy group, an oxetanyl group, an oxazoline structure, a cyclocarbonate group, a blocked isocyanate group, a hydroxy group, and an alkoxy group, and a crosslinkable compound (c-2) having a polymerizable unsaturated group.
Specific preferred examples of the crosslinkable compounds (c-1) and (c-2) include the following compounds: Compounds having an epoxy group include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, bisphenol A type epoxy resins such as Epicoat 828 (manufactured by Mitsubishi Chemical Corporation), and bisphenol A type epoxy resins such as Epicoat 807 (manufactured by Mitsubishi Chemical Corporation). Phenol F type epoxy resins, hydrogenated bisphenol A type epoxy resins such as YX-8000 (manufactured by Mitsubishi Chemical Corporation), biphenyl skeleton-containing epoxy resins such as YX6954BH30 (manufactured by Mitsubishi Chemical Corporation), phenol novolac type epoxy resins such as EPPN-201 (manufactured by Nippon Kayaku Co., Ltd.), (o, m, p-)cresol novolac type epoxy resins such as EOCN-102S (manufactured by Nippon Kayaku Co., Ltd.), tetrakis(glycidyloxymethyl)methane, N,N,N',N'-tetraglycidyl-1,4-phenylenediamine, N,N,N',N'-tetraglycidyl-2,2'-dimethyl-4.4'-diaminobiphenyl, 2,2-bis[4-(N,N-diglycidyl-4-aminophenoxy) compounds in which a tertiary nitrogen atom is bonded to an aromatic carbon atom, such as N,N,N',N'-tetraglycidyl-1,2-diaminocyclohexane, N,N,N',N'-tetraglycidyl-1,3-diaminocyclohexane, N,N,N',N'-tetraglycidyl-1,4-diaminocyclohexane, bis(N,N-diglycidyl-4-aminocyclohexyl)methane, bis(N,N-diglycidyl-2-methyl-4-aminocyclohexyl)methane, bis(N,N-diglycidyl-3-methyl-4-aminocyclohexyl)methane, 1,3-bis(N,N-diglycidyl a compounds in which a tertiary nitrogen atom is bonded to an aliphatic carbon atom, such as 1,4-bis(N,N-diglycidylaminomethyl)cyclohexane, 1,4-bis(N,N-diglycidylaminomethyl)cyclohexane, 1,3-bis(N,N-diglycidylaminomethyl)benzene, 1,4-bis(N,N-diglycidylaminomethyl)benzene, 1,3,5-tris(N,N-diglycidylaminomethyl)cyclohexane, and 1,3,5-tris(N,N-diglycidylaminomethyl)benzene; isocyanurate compounds such as triglycidyl isocyanurate, such as TEPIC (manufactured by Nissan Chemical Industries, Ltd.); compounds described in paragraph [0037] of JP-A-10-338880; and compounds described in WO2017/170483;
Examples of compounds having an oxetanyl group include 1,4-bis{[(3-ethyl-3-oxetanyl)methoxy]methyl}benzene (ARON OXETANE OXT-121 (XDO)), bis[2-(3-oxetanyl)butyl]ether (ARON OXETANE OXT-221 (DOX)), 1,4-bis[(3-ethyloxetan-3-yl)methoxy]benzene (HQOX), 1,3-bis[(3-ethyloxetan-3-yl)methoxy]benzene (RSOX), 1,2-bis[(3-ethyloxetan-3-yl)methoxy]benzene (CTOX), and compounds having two or more oxetanyl groups described in paragraphs [0170] to [0175] of WO2011/132751;
Examples of compounds having an oxazoline structure include compounds such as 2,2'-bis(2-oxazoline) and 2,2'-bis(4-methyl-2-oxazoline), polymers and oligomers having an oxazoline group such as EPOCROS (trade name, manufactured by Nippon Shokubai Co., Ltd.), and compounds described in paragraph [0115] of JP 2007-286597 A;
Examples of compounds having a cyclocarbonate group include N,N,N',N'-tetra[(2-oxo-1,3-dioxolan-4-yl)methyl]-4,4'-diaminodiphenylmethane, N,N',-di[(2-oxo-1,3-dioxolan-4-yl)methyl]-1,3-phenylenediamine, and the compounds described in paragraphs [0025] to [0030] and [0032] of WO2011/155577;
Examples of compounds having a blocked isocyanate group include Coronate AP Stable M, Coronate 2503, 2515, 2507, 2513, 2555, and Millionate MS-50 (all manufactured by Tosoh Corporation), and Takenate B-830, B-815N, B-820NSU, B-842N, B-846N, B-870N, B-874N, and B-882N (all manufactured by Mitsui Chemicals, Inc.). specific examples of commercially available compounds such as those mentioned above, compounds represented by the following formulas (bL-1) to (bL-3), compounds having two or more protected isocyanate groups described in paragraphs [0046] to [0047] of JP 2014-224978 A, compounds having three or more protected isocyanate groups described in paragraphs [0119] to [0120] of WO 2015/141598 A, and the like;

Examples of compounds having a hydroxy group and/or an alkoxy group include N,N,N',N'-tetrakis(2-hydroxyethyl)adipamide, compounds represented by the following formulas (pL-1) to (pL-4), 2,2-bis(4-hydroxy-3,5-dihydroxymethylphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethoxyphenyl)propane, 2,2-bis(4-hydroxy-3,5-dihydroxymethylphenyl)-1,1,1,3,3,3-hexafluoropropane, compounds described in WO2015/072554 and paragraph [0058] of JP2016-118753A, compounds described in JP2016-200798A, compounds described in WO2010/074269A, and the like;

Examples of crosslinkable compounds having a polymerizable unsaturated group include glycerin mono(meth)acrylate, glycerin di(meth)acrylate (1,2-,1,3-mixture), glycerin tris(meth)acrylate, glycerol 1,3-diglycerolate di(meth)acrylate, pentaerythritol tri(meth)acrylate, diethylene glycol mono(meth)acrylate, triethylene glycol mono(meth)acrylate, tetraethylene glycol mono(meth)acrylate, pentaethylene glycol mono(meth)acrylate, and hexaethylene glycol mono(meth)acrylate.

The above compounds are examples of crosslinkable compounds, and are not limited to these. For example, other components than those mentioned above disclosed on pages 53 [0105] to 55 [0116] of WO2015/060357 may be used. Two or more types of crosslinkable compounds may be used in combination.

When a crosslinkable compound is used, the content of the crosslinkable compound in the liquid crystal alignment agent is preferably 0.5 to 20 parts by mass, and more preferably 1 to 15 parts by mass, per 100 parts by mass of the polymer component contained in the liquid crystal alignment agent.

Examples of the adhesion aid include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldiethoxymethylsilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyl trimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-3-triethoxysilylpropyltriethylenetetramine, N-3-trimethoxysilylpropyltriethylenetetramine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyltrimethoxysilane, N- Benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxy Examples of silane coupling agents include silane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, tris[3-(trimethoxysilyl)propyl]isocyanurate, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-isocyanatopropyltriethoxysilane.
When an adhesion assistant is used, the content of the adhesion assistant in the liquid crystal alignment agent is preferably 0.1 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, per 100 parts by mass of the polymer component contained in the liquid crystal alignment agent.
Dielectric or conductive materials include, for example, monoamines having a nitrogen-containing aromatic heterocycle, such as 3-picolylamine.
When a dielectric or conductive substance is used, the content of the dielectric or conductive substance in the liquid crystal alignment agent is preferably 0.1 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, per 100 parts by mass of the polymer component contained in the liquid crystal alignment agent.

(Liquid crystal alignment film)
The liquid crystal alignment film of the present invention is formed using the liquid crystal aligning agent of the present invention.
The method for producing a liquid crystal alignment film of the present invention includes, for example, applying the above-mentioned liquid crystal alignment agent to a substrate, baking the same, and irradiating the resulting film with polarized radiation.
A preferred embodiment of the method for producing a liquid crystal alignment film of the present invention includes, for example, a step of applying the above-mentioned liquid crystal alignment agent to a substrate (step (1)), a step of baking the applied liquid crystal alignment agent (step (2)), and, in some cases, a step of performing an alignment treatment on the film obtained in step (2) (step (3)).

<Step (1)>
The substrate to which the liquid crystal alignment agent used in the present invention is applied is not particularly limited as long as it is a highly transparent substrate, and a glass substrate, a silicon nitride substrate, an acrylic substrate, a plastic substrate such as a polycarbonate substrate, etc. can also be used. In this case, it is preferable to use a substrate on which an ITO (Indium Tin Oxide) electrode for driving the liquid crystal is formed from the viewpoint of simplifying the process. In addition, in a reflective liquid crystal display element, an opaque material such as a silicon wafer can be used for only one substrate, and in this case, a material that reflects light such as aluminum can also be used for the electrode. Furthermore, when manufacturing a liquid crystal display element of an IPS driving system or an FFS driving system, a substrate on which an electrode made of a transparent conductive film or a metal film patterned into a comb tooth shape is provided and an opposing substrate on which no electrode is provided are used.

Methods for applying the liquid crystal alignment agent to a substrate and forming a film include screen printing, offset printing, flexographic printing, the inkjet method, and the spray method. Among these, the inkjet method is the most suitable for application and film formation.

An IPS substrate, which is a comb-tooth electrode substrate used in the IPS system (mode), has a base material, a plurality of linear electrodes formed on the base material and arranged in a comb-tooth shape, and a liquid crystal alignment film formed on the base material so as to cover the linear electrodes.
The FFS substrate, which is a comb-tooth electrode substrate used in the FFS method (mode), has a base material, a surface electrode formed on the base material, an insulating film formed on the surface electrode, a plurality of linear electrodes formed on the insulating film and arranged in a comb-tooth shape, and a liquid crystal alignment film formed on the insulating film so as to cover the linear electrodes.

FIG. 1 is a schematic cross-sectional view showing an example of an IPS mode in-plane switching liquid crystal display device having a liquid crystal alignment film obtained from the liquid crystal aligning agent of the present invention.
In the in-plane switching liquid crystal display element 1 illustrated in Fig. 1, liquid crystal 3 is sandwiched between a comb-tooth electrode substrate 2 having a liquid crystal alignment film 2c and a counter substrate 4 having a liquid crystal alignment film 4a. The comb-tooth electrode substrate 2 has a base material 2a, a plurality of linear electrodes 2b formed on the base material 2a and arranged in a comb-tooth shape, and a liquid crystal alignment film 2c formed on the base material 2a so as to cover the linear electrodes 2b. The counter substrate 4 has a base material 4b and a liquid crystal alignment film 4a formed on the base material 4b. The liquid crystal alignment film 2c is the liquid crystal alignment film of the present invention. The liquid crystal alignment film 4c is also the liquid crystal alignment film of the present invention.
In the IPS LCD element 1 of FIG. 1, when a voltage is applied to the linear electrodes 2b, an electric field is generated between the linear electrodes 2b as indicated by electric field lines L.

FIG. 2 is a schematic cross-sectional view showing an example of an FFS mode in-plane switching liquid crystal display device having a liquid crystal alignment film obtained from the liquid crystal aligning agent of the present invention.
In the lateral electric field liquid crystal display element 1 illustrated in Fig. 2, liquid crystal 3 is sandwiched between a comb-tooth electrode substrate 2 having a liquid crystal alignment film 2h and a counter substrate 4 having a liquid crystal alignment film 4a. The comb-tooth electrode substrate 2 has a base material 2d, a plane electrode 2e formed on the base material 2d, an insulating film 2f formed on the plane electrode 2e, a plurality of linear electrodes 2g formed on the insulating film 2f and arranged in a comb-tooth shape, and a liquid crystal alignment film 2h formed on the insulating film 2f so as to cover the linear electrodes 2g. The counter substrate 4 has a base material 4b and a liquid crystal alignment film 4a formed on the base material 4b. The liquid crystal alignment film 2h is the liquid crystal alignment film of the present invention. The liquid crystal alignment film 4a is also the liquid crystal alignment film of the present invention.
In the IPS LCD element 1 shown in FIG. 2, when a voltage is applied to the plane electrodes 2e and the linear electrodes 2g, an electric field is generated between the plane electrodes 2e and the linear electrodes 2g as indicated by electric field lines L.

<Step (2)>
Step (2) is a step of baking the liquid crystal alignment agent applied on the substrate to form a film. After the liquid crystal alignment agent is applied on the substrate, the solvent can be evaporated or the amic acid or amic acid ester in the polymer can be thermally imidized by a heating means such as a hot plate, a heat circulation oven, or an IR (infrared) oven. The drying and baking steps after the application of the liquid crystal alignment agent of the present invention can be performed at any temperature and time, and may be performed multiple times. The temperature at which the solvent of the liquid crystal alignment agent is evaporated can be, for example, 40 to 180°C as the temperature of the heating means, but may be 40 to 150°C from the viewpoint of shortening the process. The baking time is not particularly limited, but is, for example, 1 to 10 minutes, preferably 1 to 5 minutes. In addition to the step of evaporating the solvent, when a step of thermally imidizing the amic acid in the polymer is performed, after the step of evaporating the solvent, a further baking step can be performed at a temperature of, for example, 150 to 300°C, preferably 150 to 250°C as the temperature of the heating means. The baking time in the thermal imidization step is not particularly limited, but is, for example, 5 to 40 minutes, and preferably 5 to 30 minutes.
If the film-like material after firing is too thin, the reliability of the liquid crystal display device may decrease, so the thickness is preferably 5 to 300 nm, and more preferably 10 to 200 nm.

<Step (3)>
Step (3) is a step of performing an alignment treatment on the film obtained in step (2). The alignment treatment method for the liquid crystal alignment film includes a rubbing treatment method and a photo-alignment treatment method, and the photo-alignment treatment method is preferable. The photo-alignment treatment method includes a method in which the surface of the film-like material is irradiated with polarized radiation in a certain direction, and optionally heated to impart liquid crystal alignment properties (also called liquid crystal alignment ability). As the radiation, ultraviolet rays or visible light having a wavelength of 100 to 800 nm can be used. Among them, ultraviolet rays having a wavelength of 100 to 400 nm are preferable, and more preferably, ultraviolet rays having a wavelength of 200 to 400 nm are preferable.

The radiation dose is preferably 1 to 10,000 mJ/ ^cm2 , and more preferably 100 to 5,000 mJ/ ^cm2 .
Examples of light sources for the irradiation light include low-pressure mercury lamps, high-pressure mercury lamps, deep UV lamps, deuterium lamps, metal halide lamps, argon resonance lamps, xenon lamps, mercury-xenon lamps, excimer lasers (e.g., KrF excimer lasers), fluorescent lamps, LED lamps, halogen lamps (e.g., sodium lamps), and microwave-excited electrodeless lamps.
Furthermore, when polarized light is used as the irradiating light, the higher the extinction ratio of the polarized light, the higher the anisotropy that can be imparted. For example, in the case of ultraviolet light, the extinction ratio of the polarized ultraviolet light is more preferably 10:1 or greater, and even more preferably 20:1 or greater.
In addition, when irradiating with radiation, in order to improve the liquid crystal alignment, the substrate having the film-like material may be irradiated while being heated at 50 to 250° C. The liquid crystal alignment film thus produced can stably align liquid crystal molecules in a certain direction.
Furthermore, the liquid crystal alignment film irradiated with polarized radiation by the above-mentioned method can be contacted with a solvent or the liquid crystal alignment film irradiated with radiation can be heat-treated.

The solvent used in the contact treatment is not particularly limited, so long as it dissolves the decomposition products generated from the film-like material by irradiation with radiation. Specific examples include water, methanol, ethanol, 2-propanol, acetone, methyl ethyl ketone, 1-methoxy-2-propanol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, methyl lactate, diacetone alcohol, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propyl acetate, butyl acetate, cyclohexyl acetate, and the like. Among these, water, 2-propanol, 1-methoxy-2-propanol, or ethyl lactate is preferred from the standpoint of versatility and solvent safety. Water, 1-methoxy-2-propanol, or ethyl lactate is more preferred. The solvent may be one type or a combination of two or more types.

The above-mentioned contact treatments include immersion treatment and spray treatment (also called spray treatment). The treatment time in these treatments is preferably 10 seconds to 1 hour in order to efficiently dissolve the decomposition products generated from the film-like material by irradiation with radiation. Of these, immersion treatment for 1 minute to 30 minutes is more preferable. The solvent during the above-mentioned contact treatment may be at room temperature or heated, but is preferably 10 to 80°C, and more preferably 20 to 50°C. In addition, ultrasonic treatment or the like may be performed as necessary in terms of the solubility of the decomposition products.

After the contact treatment, it is preferable to perform rinsing (also called rinsing) with a low boiling point solvent such as water, methanol, ethanol, 2-propanol, acetone, methyl ethyl ketone, etc., and calcination. In this case, either rinsing or calcination may be performed, or both may be performed. The calcination temperature is preferably 150 to 300°C, more preferably 180 to 250°C, and even more preferably 200 to 230°C. The calcination time is preferably 10 seconds to 30 minutes, and more preferably 1 minute to 10 minutes.
The heat treatment of the coating film irradiated with the above radiation is preferably carried out at 50 to 300° C. for 1 to 30 minutes, and more preferably at 120 to 250° C. for 1 to 30 minutes.

(Liquid crystal display element)
The liquid crystal display element of the present invention has the liquid crystal alignment film of the present invention.
The liquid crystal alignment film of the present invention is suitable as a liquid crystal alignment film for a liquid crystal display element of a horizontal electric field type such as an IPS type or an FFS type, from the viewpoint of obtaining high liquid crystal alignment properties, and is particularly useful as a liquid crystal alignment film for a liquid crystal display element of an FFS type.
A liquid crystal display element can be manufactured by obtaining a substrate with a liquid crystal alignment film obtained from the liquid crystal alignment agent of the present invention, preparing a liquid crystal cell by a known method, and disposing a liquid crystal in the liquid crystal cell. Specifically, the following two methods can be mentioned.

In the first method, first, two substrates are placed facing each other with a gap (cell gap) between them so that their liquid crystal alignment films face each other. Next, the periphery of the two substrates is bonded together using a sealant, and the liquid crystal composition is injected and filled into the substrate surfaces and the cell gap defined by the sealant so that it comes into contact with the film surface, and then the injection hole is sealed.

The second method is called the ODF (One Drop Fill) method. For example, a UV-curable sealant is applied to a specified location on one of the two substrates on which a liquid crystal alignment film has been formed, and liquid crystal composition is then dropped onto several specified locations on the liquid crystal alignment film surface. The other substrate is then attached so that the liquid crystal alignment film faces the other substrate, and the liquid crystal composition is spread over the entire surface of the substrate and brought into contact with the film surface. Next, the entire surface of the substrate is irradiated with UV light to cure the sealant.

In either the first method or the second method, it is further desirable to heat the liquid crystal composition used to a temperature at which it assumes an isotropic phase, and then slowly cool it to room temperature to remove flow alignment that occurs during liquid crystal filling.
When the coating films are subjected to a rubbing treatment, the two substrates are disposed opposite each other so that the rubbing directions of the coating films are at a predetermined angle, for example, perpendicular or anti-parallel to each other. Similarly, when a photo-alignment treatment is performed, the substrates are disposed opposite each other so that the alignment directions are at a predetermined angle, for example, perpendicular or anti-parallel to each other.
The sealing agent may be, for example, an epoxy resin containing a hardener and aluminum oxide spheres as spacers. The liquid crystal may be a nematic liquid crystal or a smectic liquid crystal, of which the nematic liquid crystal is preferred.

The liquid crystal composition is not particularly limited, and is a composition containing at least one type of liquid crystal compound (liquid crystal molecule), and may be either a liquid crystal composition having a positive dielectric anisotropy (also called a positive type liquid crystal composition or positive type liquid crystal) or a liquid crystal composition having a negative dielectric anisotropy (also called a negative type liquid crystal composition or negative type liquid crystal), although a negative type liquid crystal material is preferred.
The liquid crystal composition may contain a liquid crystal compound having a fluorine atom, a hydroxy group, an amino group, a fluorine atom-containing group (e.g., a trifluoromethyl group), a cyano group, an alkyl group, an alkoxy group, an alkenyl group, an isothiocyanate group, a heterocycle, a cycloalkane, a cycloalkene, a steroid skeleton, a benzene ring, or a naphthalene ring, or may contain a compound having two or more rigid portions (mesogenic skeletons) that exhibit liquid crystallinity in the molecule (e.g., a bimesogenic compound in which two rigid biphenyl structures or terphenyl structures are linked by an alkyl group). The liquid crystal composition may be a liquid crystal composition exhibiting a nematic phase, a liquid crystal composition exhibiting a smectic phase, or a liquid crystal composition exhibiting a cholesteric phase.
In order to improve the alignment of the liquid crystal, the liquid crystal composition may further contain additives, such as photopolymerizable monomers having a polymerizable group, optically active compounds (e.g., S-811 manufactured by Merck, etc.), antioxidants, ultraviolet absorbers, dyes, antifoaming agents, polymerization initiators, or polymerization inhibitors.
Examples of the positive type liquid crystal include ZLI-2293, ZLI-4792, MLC-2003, MLC-2041, MLC-3019, and MLC-7081 manufactured by Merck.
Examples of negative type liquid crystals include MLC-6608, MLC-6609, MLC-6610, MLC-6882, MLC-6886, MLC-7026, MLC-7026-000, MLC-7026-100, and MLC-7029 manufactured by Merck.
In the PSA mode, MLC-3023 manufactured by Merck is an example of a liquid crystal containing a compound having a polymerizable group.
Next, polarizing plates are installed. Specifically, a pair of polarizing plates are attached to the surfaces of the two substrates opposite to the liquid crystal layer. Examples of polarizing plates include a polarizing film called an "H film" in which polyvinyl alcohol is stretched and oriented while iodine is absorbed, sandwiched between cellulose acetate protective films, and a polarizing plate made of the H film itself.

The present invention will be described in more detail below with reference to examples, but the present invention should not be construed as being limited to these. The abbreviations of the compounds used and the methods for measuring the various physical properties are as follows:

(Organic solvent)
NMP: N-methyl-2-pyrrolidone NEP: N-ethyl-2-pyrrolidone GBL: γ-butyrolactone MDPA: 3-methoxy-N,N-dimethylpropanamide BCS: Butyl cellosolve (ethylene glycol monobutyl ether)
DAA: Diacetone alcohol

(Tetracarboxylic acid dianhydride)

(Diamine)

(Amino-Terminal Modifier)
Ac ₂ O: acetic anhydride MA: maleic anhydride PA: propionic anhydride SA: succinic anhydride TESPSA: 3-triethoxysilylpropylsuccinic anhydride Compound (e): a compound of the following structural formula

(Additives)
AD-1: Acetic acid AD-2: 3-glycidoxypropyltriethoxysilane AD-3 to AD-6: Compounds of the following structural formula

<Measurement of Viscosity>
The measurement was performed at 25° C. using an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.) with a sample volume of 1.1 mL and a cone rotor TE-1 (1°34′, R24).
<Evaluation of the Presence of Terminal Amino Groups>
2.0 g of the polyamic acid solution was added to 10 g of isopropyl alcohol, and the resulting precipitate was filtered off. The precipitate was washed with isopropyl alcohol and dried under reduced pressure at 60°C to obtain a polyamic acid powder, which was then subjected to structural analysis by ^1H -NMR analysis. The abundance rate of the terminal amino groups was calculated from the ratio of the peak intensity of the terminal amino groups of each polyamic acid powder to the peak intensity of the terminal amino groups of the polyamic acid powder that was not end-modified (analysis conditions are as follows).
Equipment: BRUKER ADVANCE III-500MHz
Measurement solvent: deuterated dimethyl sulfoxide (DMSO-d ₆ ) or deuterated chloroform (CDCl ₃ )
Reference substance: tetramethylsilane (TMS) (δ 0.0 ppm for 1H)

[Synthesis of Amino Terminal Modifiers]
Compound (e) is a novel compound that has not been disclosed in any literature, and the synthesis method thereof will be described in detail below.

Compound (e) was identified by ¹ H-NMR analysis (analysis conditions are as follows).
Equipment: BRUKER ADVANCE III-500MHz
Measurement solvent: deuterated dimethyl sulfoxide (DMSO-d ₆ ) or deuterated chloroform (CDCl ₃ )
Reference substance: tetramethylsilane (TMS) (δ 0.0 ppm for ¹ H)

The abbreviations used in the present invention have the following meanings.
BOP Reagent: Benzotriazolyl-N-hydroxytris(dimethylamino)phosphonium hexafluorophosphate salt

　フラスコ内に、Ｎ，Ｎ’－ジ－ｔｅｒｔ－ブトキシカルボニル－ヒスチジン（１７．７ｇ、４９．８ｍｍｏｌ）、トリエチルアミン（Ｅｔ_３Ｎ、６．２８ｇ，６２．１ｍｍｏｌ）及びジクロロメタン（ＣＨ_２Ｃｌ_２、２４７ｇ）を加え、得られた溶液を２℃に冷却した。さらに、ＢＯＰ試薬（２２．１ｇ、５０．０ｍｍｏｌ）を上記フラスコ内に加えて、１０℃で１時間撹拌し、反応させた。反応後、析出した結晶を濾別し、２－プロパノール（７０．０ｇ）で２回、アセトニトリル（７０．０ｇ）で２回固体を洗浄し、得られた湿品を４０℃で真空乾燥させることで化合物（ｅ）を得た（収量：８．３１ｇ，１７．６ｍｍｏｌ，性状：白色固体，収率：３５％）。以下に示す^１Ｈ－ＮＭＲの結果から、この固体が化合物（ｅ）であることを確認した。
^１Ｈ－ＮＭＲ（５００ＭＨｚ）　ｉｎ　ＣＤＣｌ_３：δ（ｐｐｍ）＝８．０９（ｄ，１Ｈ，Ｊ＝１．０Ｈｚ），８．０３（ｄ，１Ｈ，Ｊ＝８．４Ｈｚ），７．６１（ｄ，１Ｈ，Ｊ＝８．３Ｈｚ），７．５２（ｔ，１Ｈ，Ｊ＝７．２Ｈｚ），７．４１（ｔ，１Ｈ，Ｊ＝８．０Ｈｚ），７．３８（ｓ，１Ｈ），６．１８（ｄ，１Ｈ，Ｊ＝７．０Ｈｚ），４．９９（ｑ，１Ｈ，Ｊ＝６．７Ｈｚ），３．３９－３．２５（ｍ，２Ｈ），１．６３（ｓ，９Ｈ），１．４８（ｓ，９Ｈ）． <Synthesis of compound (e)>

Into the flask, N,N'-di-tert-butoxycarbonyl-histidine (17.7 g, 49.8 mmol), triethylamine (Et ₃ N, 6.28 g, 62.1 mmol) and dichloromethane (CH ₂ Cl ₂ , 247 g) were added, and the resulting solution was cooled to 2°C. Furthermore, BOP reagent (22.1 g, 50.0 mmol) was added to the flask, and the mixture was stirred at 10°C for 1 hour to react. After the reaction, the precipitated crystals were filtered off, and the solid was washed twice with 2-propanol (70.0 g) and twice with acetonitrile (70.0 g), and the resulting wet product was vacuum-dried at 40°C to obtain compound (e) (yield: 8.31 g, 17.6 mmol, properties: white solid, yield: 35%). From the results of ¹ H-NMR shown below, it was confirmed that this solid was compound (e).
¹ H-NMR (500 MHz) in CDCl ₃ : δ (ppm) = 8.09 (d, 1 H, J = 1.0 Hz), 8.03 (d, 1 H, J = 8.4 Hz), 7.61 (d, 1 H, J = 8.3 Hz), 7.52 (t, 1 H, J = 7.2 Hz), 7. 41 (t, 1H, J = 8.0Hz), 7.38 (s, 1H), 6.18 (d, 1H, J = 7.0Hz), 4.99 (q, 1H, J = 6.7Hz), 3.39-3.25 (m, 2H), 1.63 (s, 9H), 1.48 (s, 9H).

[Synthesis of polymer]
<Synthesis Example 1>
0.54 g (5.0 mmol) of DA-1, 1.83 g (7.5 mmol) of DA-2, 2.40 g (7.5 mmol) of DA-3, and 1.99 g (5.0 mmol) of DA-4 were weighed out into a 100 mL eggplant flask equipped with a stirrer and a nitrogen inlet tube, 77.8 g of NMP was added, and the mixture was dissolved by stirring while feeding nitrogen. While stirring this diamine solution under water cooling, 5.32 g (24.0 mmol) of CA-1 was added, and further 10.8 g of NMP was added, and the mixture was stirred under a nitrogen atmosphere at 40° C. for 20 hours to obtain a polymer solution A-1.
<Synthesis Example 2>
5.26 g (26.4 mmol) of DA-5 and 1.00 g (6.6 mmol) of DA-6 were weighed out into a 100 mL recovery flask equipped with a stirrer and a nitrogen inlet tube, 45.9 g of NMP was added, and the mixture was dissolved by stirring while feeding nitrogen. While stirring this diamine solution under water cooling, 9.03 g (30.7 mmol) of CA-2 was added, and further 66.2 g of NMP was added, and the mixture was stirred under a nitrogen atmosphere at 70° C. for 10 hours to obtain a polymer solution B-1.

<Synthesis Example 3>
To the above polymer solution A-1 (30 g), 0.05 g (0.5 mmol) of Ac ₂ O was added and stirred at room temperature for 24 hours to obtain a polymer solution C-1 containing a non-amino terminal structure.
<Synthesis Example 4>
To the above polymer solution B-1 (30 g), 0.06 g (0.6 mmol) of Ac ₂ O was added and stirred at room temperature for 24 hours to obtain a polymer solution D-1 containing a non-amino terminal structure.
<Synthesis Examples 5 to 16>
The same operations as in Synthesis Examples 3 and 4 were carried out using the polymer solutions and amino terminal modifiers shown in Table 1 below, to obtain polymer solutions C-2 to 11 and D-2 to 3.
<Synthesis Example 17>
To 30 g of the above polymer solution A-1, 0.18 g (3.0 mmol) of AD-1 was added, and the mixture was stirred at room temperature for 24 hours to obtain a polymer solution E-1 not containing a non-amino terminal structure.

[Synthesis of polymer]
<Synthesis Example 18>
5.41 g (50.0 mmol) of DA-1 was weighed out into a 100 mL recovery flask equipped with a stirrer and a nitrogen inlet tube, 39.7 g of NMP was added, and the mixture was dissolved by stirring while feeding nitrogen. While stirring this diamine solution under water cooling, 10.54 g (47.0 mmol) of CA-1 was added, and further 77.3 g of NMP was added, and the mixture was stirred under a nitrogen atmosphere at 40° C. for 20 hours to obtain a polymer solution A-2.
<Synthesis Example 19>
12.21 g (50.0 mmol) of DA-2 was weighed out into a 100 mL recovery flask equipped with a stirrer and a nitrogen inlet tube, 89.6 g of NMP was added, and the mixture was dissolved by stirring while feeding nitrogen. While stirring this diamine solution under water cooling, 10.54 g (47.0 mmol) of CA-1 was added, and further 77.3 g of NMP was added, and the mixture was stirred under a nitrogen atmosphere at 40° C. for 20 hours to obtain a polymer solution A-3.
<Synthesis Example 20>
19.93 g (50.0 mmol) of DA-4 was weighed out into a 100 mL recovery flask equipped with a stirrer and a nitrogen inlet tube, 146.1 g of NMP was added, and the mixture was dissolved by stirring while feeding nitrogen. While stirring this diamine solution under water cooling, 10.54 g (47.0 mmol) of CA-1 was added, and further 77.3 g of NMP was added, and the mixture was stirred under a nitrogen atmosphere at 40° C. for 20 hours to obtain a polymer solution A-4.
<Synthesis Example 21>
10.61 g (50.0 mmol) of DA-7 was weighed out into a 100 mL recovery flask equipped with a stirrer and a nitrogen inlet tube, 77.8 g of NMP was added, and the mixture was dissolved by stirring while feeding nitrogen. While stirring this diamine solution under water cooling, 10.54 g (47.0 mmol) of CA-1 was added, and further 77.3 g of NMP was added, and the mixture was stirred under a nitrogen atmosphere at 40° C. for 20 hours to obtain a polymer solution A-5.
<Synthesis Example 22>
10.61 g (50.0 mmol) of DA-8 was weighed out into a 100 mL recovery flask equipped with a stirrer and a nitrogen inlet tube, 77.8 g of NMP was added, and the mixture was dissolved by stirring while feeding nitrogen. While stirring this diamine solution under water cooling, 10.54 g (47.0 mmol) of CA-1 was added, and further 77.3 g of NMP was added, and the mixture was stirred under a nitrogen atmosphere at 40° C. for 20 hours to obtain a polymer solution A-6.
<Synthesis Example 23>
20.22 g (50.0 mmol) of DA-9 was weighed out into a 100 mL recovery flask equipped with a stirrer and a nitrogen inlet tube, 148.3 g of NMP was added, and the mixture was dissolved by stirring while feeding nitrogen. While stirring this diamine solution under water cooling, 10.54 g (47.0 mmol) of CA-1 was added, and further 77.3 g of NMP was added, and the mixture was stirred under a nitrogen atmosphere at 40° C. for 20 hours to obtain a polymer solution A-7.
<Synthesis Example 24>
In a 100 mL eggplant flask equipped with a stirrer and a nitrogen inlet tube, 1.06 g (5.0 mmol) of DA-7, 1.83 g (7.5 mmol) of DA-2, 2.40 g (7.5 mmol) of DA-3, and 1.99 g (5.0 mmol) of DA-4 were weighed out, 53.5 g of NMP was added, and the mixture was dissolved by stirring while feeding nitrogen. While stirring this diamine solution under water cooling, 5.32 g (24.0 mmol) of CA-1 was added, and further 39.0 g of NMP was added, and the mixture was stirred under a nitrogen atmosphere at 40° C. for 20 hours to obtain a polymer solution A-8.
<Synthesis Example 25>
0.54 g (5.0 mmol) of DA-1, 1.59 g (7.5 mmol) of DA-8, 2.40 g (7.5 mmol) of DA-3, and 1.99 g (5.0 mmol) of DA-4 were weighed out into a 100 mL eggplant flask equipped with a stirrer and a nitrogen inlet tube, 47.9 g of NMP was added, and the mixture was dissolved by stirring while feeding nitrogen. While stirring this diamine solution under water cooling, 5.32 g (24.0 mmol) of CA-1 was added, and further 39.0 g of NMP was added, and the mixture was stirred under a nitrogen atmosphere at 40° C. for 20 hours to obtain a polymer solution A-9.
<Synthesis Example 26>
0.54 g (5.0 mmol) of DA-1, 1.83 g (7.5 mmol) of DA-2, 2.40 g (7.5 mmol) of DA-3, and 2.02 g (5.0 mmol) of DA-9 were weighed out into a 100 mL eggplant flask equipped with a stirrer and a nitrogen inlet tube, 49.9 g of NMP was added, and the mixture was dissolved by stirring while feeding nitrogen. While stirring this diamine solution under water cooling, 5.32 g (24.0 mmol) of CA-1 was added, and further 39.0 g of NMP was added, and the mixture was stirred under a nitrogen atmosphere at 40° C. for 20 hours to obtain a polymer solution A-10.
<Synthesis Example 27>
In a 100 mL eggplant flask equipped with a stirrer and a nitrogen inlet tube, 1.08 g (10.0 mmol) of DA-1, 1.83 g (7.5 mmol) of DA-2, and 2.40 g (7.5 mmol) of DA-3 were weighed out, 39.0 g of NMP was added, and the mixture was dissolved by stirring while feeding nitrogen. While stirring this diamine solution under water cooling, 5.32 g (24.0 mmol) of CA-1 was added, and further 39.0 g of NMP was added, and the mixture was stirred under a nitrogen atmosphere at 40° C. for 20 hours to obtain a polymer solution A-11.
<Synthesis Example 28>
0.54 g (5.0 mmol) of DA-1, 1.83 g (7.5 mmol) of DA-2, 2.40 g (7.5 mmol) of DA-3, and 1.19 g (5.0 mmol) of DA-10 were weighed out into a 100 mL eggplant flask equipped with a stirrer and a nitrogen inlet tube, 43.7 g of NMP was added, and the mixture was dissolved by stirring while feeding nitrogen. While stirring this diamine solution under water cooling, 5.32 g (24.0 mmol) of CA-1 was added, and further 39.0 g of NMP was added, and the mixture was stirred under a nitrogen atmosphere at 40° C. for 20 hours to obtain a polymer solution A-12.
<Synthesis Example 29>
0.54 g (5.0 mmol) of DA-1, 1.83 g (7.5 mmol) of DA-2, 2.40 g (7.5 mmol) of DA-3, and 1.71 g (5.0 mmol) of DA-11 were weighed out into a 100 mL eggplant flask equipped with a stirrer and a nitrogen inlet tube, 47.5 g of NMP was added, and the mixture was dissolved by stirring while feeding nitrogen. While stirring this diamine solution under water cooling, 5.32 g (24.0 mmol) of CA-1 was added, and further 39.0 g of NMP was added, and the mixture was stirred under a nitrogen atmosphere at 40° C. for 20 hours to obtain a polymer solution A-13.
<Synthesis Example 30>
0.54 g (5.0 mmol) of DA-1, 1.83 g (7.5 mmol) of DA-2, 2.40 g (7.5 mmol) of DA-3, and 1.98 g (5.0 mmol) of DA-12 were weighed out into a 100 mL eggplant flask equipped with a stirrer and a nitrogen inlet tube, 49.6 g of NMP was added, and the mixture was dissolved by stirring while feeding nitrogen. While stirring this diamine solution under water cooling, 5.32 g (24.0 mmol) of CA-1 was added, and further 39.0 g of NMP was added, and the mixture was stirred under a nitrogen atmosphere at 40° C. for 20 hours to obtain a polymer solution A-14.
<Synthesis Example 31>
0.54 g (5.0 mmol) of DA-1, 1.83 g (7.5 mmol) of DA-2, 2.40 g (7.5 mmol) of DA-3, and 2.78 g (5.0 mmol) of DA-13 were weighed out into a 100 mL eggplant flask equipped with a stirrer and a nitrogen inlet tube, 55.4 g of NMP was added, and the mixture was dissolved by stirring while feeding nitrogen. While stirring this diamine solution under water cooling, 5.32 g (24.0 mmol) of CA-1 was added, and further 39.0 g of NMP was added, and the mixture was stirred under a nitrogen atmosphere at 40° C. for 20 hours to obtain a polymer solution A-15.
<Synthesis Example 32>
0.54 g (5.0 mmol) of DA-1, 1.83 g (7.5 mmol) of DA-2, 2.40 g (7.5 mmol) of DA-3, and 1.94 g (5.0 mmol) of DA-14 were weighed out into a 100 mL eggplant flask equipped with a stirrer and a nitrogen inlet tube, 49.2 g of NMP was added, and the mixture was dissolved by stirring while feeding nitrogen. While stirring this diamine solution under water cooling, 5.32 g (24.0 mmol) of CA-1 was added, and further 39.0 g of NMP was added, and the mixture was stirred under a nitrogen atmosphere at 40° C. for 20 hours to obtain a polymer solution A-16.
<Synthesis Example 33>
4.48 g (15.0 mmol) of DA-15 and 2.44 g (10.0 mmol) of DA-2 were weighed out into a 100 mL recovery flask equipped with a stirrer and a nitrogen inlet tube, 50.7 g of NMP was added, and the mixture was dissolved by stirring while feeding nitrogen. While stirring this diamine solution under water cooling, 6.99 g (24.0 mmol) of CA-2 was added, and further 51.2 g of NMP was added, and the mixture was stirred under a nitrogen atmosphere at 70° C. for 10 hours to obtain polymer solution B-2.
<Synthesis Example 34>
3.99 g (20.0 mmol) of DA-5 and 1.22 g (5.0 mmol) of DA-2 were weighed out into a 100 mL recovery flask equipped with a stirrer and a nitrogen inlet tube, 49.3 g of NMP was added, and the mixture was dissolved by stirring while feeding nitrogen. While stirring this diamine solution under water cooling, 4.41 g (22.5 mmol) of CA-3 was added, and further 21.2 g of NMP was added, and the mixture was stirred under a nitrogen atmosphere at 40° C. for 10 hours to obtain polymer solution B-3.
<Synthesis Example 35>
2.16 g (20.0 mmol) of DA-1 and 0.54 g (5.0 mmol) of DA-16 were weighed out into a 100 mL eggplant flask equipped with a stirring device and a nitrogen inlet tube, 40.9 g of NMP was added, and the mixture was stirred and dissolved while feeding nitrogen. While stirring this diamine solution under water cooling, 1.56 g (6.3 mmol) of CA-4 was added, and further 5.0 g of NMP was added, and the mixture was stirred at 50°C under a nitrogen atmosphere for 3 hours. Thereafter, while stirring this solution under water cooling, 3.53 g (18.0 mmol) of CA-3 was added, and further 11.2 g of NMP was added, and the mixture was stirred at 25°C under a nitrogen atmosphere for 12 hours to obtain a polymer solution B-4.
<Synthesis Example 36>
2.99 g (15.0 mmol) of DA-5, 2.11 g (5.0 mmol) of DA-17, and 1.49 g (5.0 mmol) of DA-15 were weighed out into a 100 mL eggplant flask equipped with a stirrer and a nitrogen inlet tube, 48.3 g of NMP was added, and the mixture was stirred and dissolved while feeding nitrogen. While stirring this diamine solution under water cooling, 6.99 g (24.0 mmol) of CA-2 was added, and further 51.2 g of NMP was added, and the mixture was stirred under a nitrogen atmosphere at 70° C. for 10 hours to obtain a polymer solution B-5.
<Synthesis Example 37>
In a 100 mL eggplant flask equipped with a stirrer and a nitrogen inlet tube, 1.87 g (7.5 mmol) of DA-18, 2.49 g (12.5 mmol) of DA-5, and 0.99 g (5.0 mmol) of DA-19 were weighed out, 39.2 g of NMP was added, and the mixture was stirred and dissolved while feeding nitrogen. While stirring this diamine solution under water cooling, 1.72 g (8.8 mmol) of CA-3 was added, and 42.0 g of NMP was further added, and the mixture was stirred at 25 ° C. under a nitrogen atmosphere for 1 hour. Thereafter, while stirring this solution under water cooling, 4.41 g (15.0 mmol) of CA-2 was added, and 2.9 g of NMP was further added, and the mixture was stirred at 25 ° C. under a nitrogen atmosphere for 5 hours to obtain a polymer solution B-6.

<Synthesis Examples 38 to 53>
The same operations as in Synthesis Examples 3 and 4 were carried out using the polymer solutions and amino terminal modifiers shown in Table 2 below, to obtain polymer solutions C-12 to C-27.

　ここで、上記ポリマー溶液（Ａ－１）～（Ａ－１６）、（Ｂ－１）～（Ｂ－６）について、合成するのに用いたテトラカルボン酸二無水物成分及びジアミン成分を下記の表３に記載する。

The tetracarboxylic dianhydride components and diamine components used in synthesizing the above polymer solutions (A-1) to (A-16) and (B-1) to (B-6) are shown in Table 3 below.

[Preparation of liquid crystal alignment agent]
Example 1
Using the above polymer solution B-1 and the above polymer solution C-1, the polymer solution C-1 (2.3 g) and the polymer solution B-1 (2.3 g) were mixed so that the mass ratio of the two types of polymers was 50:50. To this mixture, NMP (9.6 g), BCS (5.0 g), an NMP solution containing 1 mass% AD-2 (0.5 g), and an NMP solution containing 10 wt% AD-3 (0.3 g) were added with stirring, and further stirred at room temperature for 2 hours to obtain the liquid crystal alignment agent (AL-1) of the present invention. In addition, a liquid crystal alignment agent (AL-1-48h) was also obtained by leaving it at room temperature for 48 hours to evaluate the deterioration suppression effect of liquid crystal alignment.

<Examples 2 to 14 and Comparative Examples 1 to 3>
The same operation as in Example 1 was carried out with the composition shown in Table 4 below, and the liquid crystal alignment agents (AL-2) to (AL-14), (AL-2-48h) to (AL-14-48h) of Examples 2 to 14 of the present invention and (AL-R1) to (AL-R3), (AL-R1-48h) to (AL-R3-48h) of Comparative Examples 1 to 3 were obtained.

<Examples 15 to 41 and Comparative Examples 4 to 30>
With the composition shown in Table 5 below, the same operation as in Example 1 was carried out to obtain the liquid crystal alignment agents (AL-15) to (AL-41), (AL-15-48h) to (AL-41-48h) of Examples 15 to 41 of the present invention and the liquid crystal alignment agents (AL-R4) to (AL-R30), (AL-R4-48h) to (AL-R30-48h) of Comparative Examples 4 to 30.

[Preparation of liquid crystal cells]
The liquid crystal alignment agent obtained above was used to prepare the following FFS drive liquid crystal cell.
(Configuration of FFS driving liquid crystal cell)
The liquid crystal cell for the FFS mode was a set of a first glass substrate on which an FOP (Finger on Plate) electrode layer consisting of a planar common electrode, an insulating layer, and a comb-shaped pixel electrode was formed on the surface, and a second glass substrate on which a columnar spacer with a height of 4 μm was formed on the surface and an ITO film for preventing static electricity was formed on the back surface. The pixel electrode had a comb-like shape in which a plurality of electrode elements with a width of 3 μm, which were bent at an inner angle of 160° at the center, were arranged in parallel at intervals of 6 μm, and one pixel had a first region and a second region with a line connecting the bends of the plurality of electrode elements as a boundary. The liquid crystal alignment film formed on the first glass substrate was oriented so that the direction dividing the inner angle of the pixel bend was orthogonal to the alignment direction of the liquid crystal, and the liquid crystal alignment film formed on the second glass substrate was oriented so that the alignment direction of the liquid crystal on the first substrate coincided with the alignment direction of the liquid crystal on the second substrate when the liquid crystal cell was produced.

(Fabrication of FFS Drive Liquid Crystal Cell (Photo-Alignment Treatment))
Next, the liquid crystal alignment agents obtained in the above Examples 1 to 14 and Comparative Examples 1 to 3 were filtered through a filter with a pore size of 1.0 μm, and then applied by spin coating to the surfaces of the above electrode-attached substrate and a glass substrate having a columnar spacer with a height of 4 μm and an ITO film formed on the back surface. After drying for 2 minutes on a hot plate at 80° C., the substrate was baked for 30 minutes in a hot air circulation oven at 230° C. to form a coating film with a thickness of 100 nm.
The coating surface was irradiated with 0.3 J/ ^cm2 of ultraviolet light having a wavelength of 254 nm and linearly polarized with an extinction ratio of 26:1 through a polarizing plate. The substrate was baked in a hot air circulating oven at 230°C for 30 minutes to obtain a substrate with a liquid crystal alignment film.

(Rubbing Alignment Treatment)
Next, a coating film having a thickness of 100 nm was formed in the same manner as above using the liquid crystal alignment agents obtained in the above Example 41 and Comparative Example 30. Next, an alignment treatment was performed by changing the above photo-alignment treatment to the following rubbing alignment treatment.
Specifically, the substrate on which the coating film was formed was rubbed with a rayon cloth (roller diameter: 140 mm, roller rotation speed: 1000 rpm, moving speed: 20 mm/sec, indentation length: 0.4 mm), then ultrasonically cleaned in pure water for 1 minute, water droplets were removed by air blowing, and the substrate was dried at 80° C. for 10 minutes to obtain a substrate with a liquid crystal alignment film.
The two substrates thus obtained were combined into a set, a sealant was applied onto one substrate, and the other substrate was attached so that the liquid crystal alignment film faces each other and the alignment direction was 0°, after which the sealant was cured to prepare an empty cell. Liquid crystal MLC-3019 (Merck) was injected into this empty cell by a reduced pressure injection method, and the injection port was sealed to prepare an FFS drive liquid crystal cell. The obtained FFS drive liquid crystal cell was heated at 120°C for 1 hour, left at 23°C overnight, and then used for the evaluation described below.

[Characteristics evaluation of liquid crystal cells]
The characteristics of the liquid crystal cell prepared above were evaluated as follows.
(Image retention characteristics due to long-term AC driving)
An AC voltage of ±7V at a frequency of 60Hz was applied to the FFS driving liquid crystal cell prepared above for 120 hours under the illumination of a backlight with an illuminance of 15000nit. After that, the pixel electrode and the counter electrode of the liquid crystal cell were shorted, and the liquid crystal cell was left at room temperature for one day. For the liquid crystal cell that had undergone the above treatment, the deviation between the alignment direction of the liquid crystal in the first region of the pixel and the alignment direction of the liquid crystal in the second region in the no voltage application state was calculated as an angle.
Specifically, a liquid crystal cell was placed between two polarizing plates arranged so that the polarization axes were perpendicular to each other, a backlight was turned on, the arrangement angle of the liquid crystal cell was adjusted so that the transmitted light intensity of the first region of the pixel was minimized, and then the rotation angle required when the liquid crystal cell was rotated so that the transmitted light intensity of the second region of the pixel was minimized was obtained. It can be said that the smaller the value of this rotation angle, the better the afterimage characteristics due to long-term AC driving.

[Evaluation Results]
In order to confirm the effect of suppressing the deterioration of the liquid crystal alignment property, which is the object of the present invention, the following evaluation was performed. Specifically, first, the rotation angle Δa of the liquid crystal cell using the liquid crystal alignment agents (AL-1) to (AL-14), (AL-R1) to (AL-R3) obtained in the above Examples 1 to 14 and Comparative Examples 1 to 3, and the rotation angle Δb of the liquid crystal cell using the liquid crystal alignment agents (AL-1-48h) to (AL-14-48h), (AL-R1-48h) to (AL-R3-48h) left at room temperature for 48 hours were calculated.
Next, the change in rotation angle Δ(|Δb-Δa|) of each liquid crystal alignment agent due to storage at room temperature was used as an index representing the degree of deterioration of the liquid crystal alignment property, and a value lower than 0.2° was defined as "O" and a value equal to or greater than 0.2° was defined as "X".
The evaluation results are shown in Table 6. In the table, the numerical values in parentheses for the tetracarboxylic acid components indicate the amount (parts by mole) of each tetracarboxylic dianhydride used per 100 parts by mole of the total amount of the tetracarboxylic acid components used in the polymerization.

It was confirmed that the liquid crystal cell using the liquid crystal aligning agent of the present invention has good liquid crystal alignment, that is, the deterioration of the liquid crystal alignment when left at room temperature is suppressed. A detailed comparison is as follows.
A comparison of Examples 1 and 2 with Comparative Example 1 shows that the lower the abundance rate of the terminal amino group, the better the liquid crystal alignment property. A comparison of Examples 2 and 10 with Comparative Examples 1 and 2 shows that the contribution of the abundance rate of the terminal amino group to the liquid crystal alignment property varies greatly depending on the type of polyamic acid. Comparative Example 3 also shows that when acetic acid is added as an additive (i.e., when the terminal amino group is not modified to have a non-amino group of formula (E)), the deterioration of the liquid crystal alignment property cannot be suppressed.
Moreover, the change in the rotation angle of the liquid crystal cell using the liquid crystal aligning agent of the present invention was all less than 0.2°, and it was confirmed that the deterioration of the liquid crystal alignment property due to being left at room temperature was suppressed.

In addition, the rotation angles Δa and Δb were calculated in the same manner for the liquid crystal alignment agents (AL-15) to (AL-41), (AL-15-48h) to (AL-41-48h), (AL-R4) to (AL-R30), (AL-R4-48h) to (AL-R30-48h) obtained in the above Examples 15 to 41 and Comparative Examples 4 to 30. Next, the change in rotation angle Δ(|Δb-Δa|) due to storage at room temperature for each liquid crystal alignment agent was used as an index representing the degree of deterioration of the liquid crystal alignment property, and if this value is lower than 0.2°, it was defined as "◯", and if it is 0.2° or more, it was defined as "×". The evaluation results are shown in Table 7.

　実施例１５～４１と比較例４～３０の比較から、ジアミン種、溶媒種、添加剤種、配向方式を変更しても液晶配向性の劣化抑制の効果があり、本発明の適用可能範囲は非常に広いことを確認した。

From a comparison between Examples 15 to 41 and Comparative Examples 4 to 30, it was confirmed that the effect of suppressing deterioration of liquid crystal alignment was achieved even when the diamine type, solvent type, additive type, and alignment method were changed, and the range of applicability of the present invention is extremely wide.

The entire contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2023-067329, filed on April 17, 2023, are hereby incorporated by reference as the disclosure of the specification of the present invention.

Claims (15)

A liquid crystal aligning agent comprising the following polymer (A) and polymer (B):
Polymer (A): A polyamic acid (A) having a structural unit derived from a tetracarboxylic acid derivative and a structural unit derived from a diamine,
The structural unit (a-1Ta) represented by the following formula (1T _a ) is contained as a structural unit derived from a tetracarboxylic acid derivative,
The diamine-derived structural unit includes a structural unit (a-1Da) represented by the following formula (1D _a ):
At least a part of the terminals of the polyamic acid (A) contains a non-amino group, and the non-amino group is a functional group represented by the following structural formula (E):
The polyamic acid (A), wherein the proportion of terminal amino groups present in the polyamic acid (A) is 60% or less based on all terminals of the polyamic acid (A).
Polymer (B): A polyamic acid (B) having a structural unit derived from a tetracarboxylic acid derivative and a structural unit derived from a diamine,
The structural unit (b-1Tb) represented by the following formula (1T _b ) is contained as a structural unit derived from a tetracarboxylic acid derivative,
The above polyamic acid, which contains a structural unit (b-1Db) represented by the following formula (1D _b ) as a structural unit derived from a diamine:

(In the formula, _Xa represents a tetravalent organic group represented by the following formula (x-1). In formula ( _1Da ), _Ya represents a divalent organic group derived from a diamine. Each Z independently represents a hydrogen atom or a monovalent organic group.)

(In formula (x-1), R ₁ to R ₄ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, a monovalent organic group having 1 to 6 carbon atoms containing a fluorine atom, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 6 carbon atoms, an alkyloxycarbonyl group having 2 to 6 carbon atoms, or a phenyl group, and at least one of R ₁ to R ₄ represents a group other than a hydrogen atom as defined above. * represents a bond.)

(In the formula, _Xb represents a tetravalent organic group derived from an aromatic tetracarboxylic dianhydride, a tetravalent organic group represented by the following formula (x-2), or a tetravalent organic group ( _T5a ) having an alicyclic structure having five or more members. In formula ( _1Db ), _Yb represents a divalent organic group derived from a diamine. Z has the same meaning as Z in formula ( _1Da ).)

(In formula (E), Q is a monovalent organic group selected from the following groups (e1) to (e3). * represents a bond.)
(e1) an acyclic hydrocarbon group having 1 to 6 carbon atoms; (e2) a monovalent organic group having 1 to 2 carboxy groups and 2 to 30 carbon atoms (however, the monovalent organic group does not include an acid anhydride group).
(e3) A monovalent organic group having two or more Boc groups and having 1 to 30 carbon atoms excluding Boc, the monovalent organic group having a protected amino moiety selected from the group consisting of *1-NH(Boc), *1-N(Boc) ₂ and *1-N(Boc)-*1 (*1 represents a bond bonded to a carbon atom). When there are two or more protected amino moieties, the protected amino moieties may be the same or different. The liquid crystal aligning agent according to claim 1, wherein (e1) is a residue derived from an acyclic aliphatic dicarboxylic acid anhydride. The liquid crystal aligning agent according to claim 1, wherein (e2) is a monovalent organic group having a residue derived from a dicarboxylic anhydride and having one or two carboxy groups (however, the monovalent organic group does not include an acid anhydride group), and the dicarboxylic anhydride is selected from a compound (e2-1) that does not have an alkoxysilane structure and a compound (e2-2) that has an alkoxysilane structure. The liquid crystal aligning agent according to claim 3, wherein the compound (e2-1) is an aromatic or aliphatic cyclic dicarboxylic acid anhydride. The compound (e2-2) is 4-(3-trimethoxysilylpropyl)cyclohexane-1,2-dicarboxylic anhydride, 4-(3-triethoxysilylpropyl)cyclohexane-1,2-dicarboxylic anhydride, 4-(3-trimethoxysilylpropyl)phthalic anhydride, 4-(3-triethoxysilylpropyl)phthalic anhydride, (carbon number 1-6)alkoxydimethylsilyl(carbon number 2-8)alkylsuccinic anhydride; di(carbon number 1-6)alkoxymethylsilyl(carbon number 2-8) ) alkyl succinic anhydride; tri(C1-6) alkoxysilyl(C2-8) alkyl succinic anhydride; 4-(3-dimethylmethoxysilylpropyl) cyclohexane-1,2-dicarboxylic anhydride, 4-(3-dimethylethoxysilylpropyl) cyclohexane-1,2-dicarboxylic anhydride, 4-(3-dimethylmethoxysilylpropyl) phthalic anhydride, or 4-(3-dimethylethoxysilylpropyl) phthalic anhydride, according to claim 3, which is selected from the group consisting of phthalic anhydride, phthalic anhydride, and phthalic anhydride. The liquid crystal aligning agent according to claim 1, wherein (e3) is obtained using an active ester compound (e) represented by R-O-C(=O)-E3 (E3 represents the above (e3). R represents an active ester forming group). E3 is a group obtained by removing a carboxy group from a carboxylic acid (W) represented by "W-COOH" (W has the same meaning as in formula (e3)),
The liquid crystal aligning agent according to claim 6, wherein the carboxylic acid (W) is obtained by protecting an amino group of a carboxyl group-containing polyamine (pA) having two or more amino groups. The liquid crystal aligning agent according to claim 1, wherein the formula (x-1) is selected from the group consisting of the following formulas (x1-1) to (x1-5):

(* represents a bond.) The liquid crystal aligning agent according to claim 1, wherein the structural unit (a-1Da) and/or the structural unit (b-1Db) is a structural unit (1D-1) derived from a diamine selected from the group consisting of diamines represented by diamine (0) "H-N(Z)-Ar ₁ -L ₁ -A-L _{1 ' -Ar 1'} -N(Z)-H", diamine (Ph) "H-N(Z)-Ar-N(Z)-H" and diamine (0)'"H-N(Z)-Ar ₂ -L ₂ -A ₂ -L 2' -Ar 2'-N(Z)-H".
(In the above formula, Ar ₁ and Ar _1' each independently represent a benzene ring, a biphenyl structure, or a naphthalene ring. Any hydrogen atom on the ring of Ar ₁ or Ar _1' may be substituted with a monovalent group. A represents a divalent organic group having an alkylene structure and having 1 to 10 carbon atoms.
L ₁ and L _1' each independently represent a single bond, -O-, -S-, -C(=O)-, -O-C(=O)-, -NR- (R represents a hydrogen atom or a monovalent organic group), -C(=O)-NR- (R represents a hydrogen atom or a monovalent organic group), or -NR-C(=O)- (R represents a hydrogen atom or a monovalent organic group).
Ar represents a benzene ring, a biphenyl structure, a naphthalene ring, or a divalent organic group represented by the following formula (Im): Any hydrogen atom on the benzene ring, biphenyl structure, or naphthalene ring of Ar may be substituted with a monovalent group.
Z has the same meaning as Z in the above formula (1D _a ).
_Ar2 and Ar2 _' each independently represent a benzene ring, a biphenyl structure, a naphthalene ring, or an aromatic heterocycle. Any hydrogen atom on the ring of _Ar2 and Ar2 _' may be substituted with a monovalent group. _A2 represents a divalent organic group having an alkylene group.
L ₂ and L _2' each independently represent a single bond, -O-, -S-, -C(=O)-, -O-C(=O)-, -NR- (R represents a hydrogen atom or a monovalent organic group), -C(=O)-NR- (R represents a hydrogen atom or a monovalent organic group), or -NR-C(=O)- (R represents a hydrogen atom or a monovalent organic group).
However, any one of _Ar2 , Ar2 _', and _A2 has a heterocycle.

(In formula (Im), X represents a tetravalent organic group obtained by removing two anhydride groups from an acyclic or alicyclic tetracarboxylic acid dianhydride.) A liquid crystal aligning agent comprising the following polymer (A) and polymer (B), which gives a liquid crystal alignment film having a change in rotation angle represented by the following formula 1 of less than 0.2°.
Polymer (A): A polyamic acid (A) having a structural unit derived from a tetracarboxylic acid derivative and a structural unit derived from a diamine,
The structural unit (a-1Ta) represented by the following formula (1T _a ) is contained as a structural unit derived from a tetracarboxylic acid derivative,
The diamine-derived structural unit includes a structural unit (a-1Da) represented by the following formula (1D _a ):
The polyamic acid (A), wherein at least a portion of the terminals of the polyamic acid (A) contain a non-amino group, and the non-amino group is a functional group represented by the following structural formula (E):
Polymer (B): A polyamic acid (B) having a structural unit derived from a tetracarboxylic acid derivative and a structural unit derived from a diamine,
The structural unit (b-1Tb) represented by the following formula (1T _b ) is contained as a structural unit derived from a tetracarboxylic acid derivative,
The above polyamic acid, which contains a structural unit (b-1Db) represented by the following formula (1D _b ) as a structural unit derived from a diamine:

(In the formula, _Xa represents a tetravalent organic group represented by the following formula (x-1). In formula ( _1Da ), _Ya represents a divalent organic group derived from a diamine. Each Z independently represents a hydrogen atom or a monovalent organic group.)

(In formula (x-1), R ₁ to R ₄ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, a monovalent organic group having 1 to 6 carbon atoms containing a fluorine atom, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 6 carbon atoms, an alkyloxycarbonyl group having 2 to 6 carbon atoms, or a phenyl group, and at least one of R ₁ to R ₄ represents a group other than a hydrogen atom as defined above. * represents a bond.)

(In the formula, _Xb represents a tetravalent organic group derived from an aromatic tetracarboxylic dianhydride, a tetravalent organic group represented by the following formula (x-2), or a tetravalent organic group ( _T5a ) having an alicyclic structure having five or more members. In formula ( _1Db ), _Yb represents a divalent organic group derived from a diamine. Z has the same meaning as Z in formula ( _1Da ).)

(In formula (E), Q is a monovalent organic group selected from the following groups (e1) to (e3). * represents a bond.)
(e1) an acyclic hydrocarbon group having 1 to 6 carbon atoms; (e2) a monovalent organic group having 1 to 2 carboxy groups and 2 to 30 carbon atoms (however, the monovalent organic group does not include an acid anhydride group).
(e3) A monovalent organic group having two or more Boc groups and having 1 to 30 carbon atoms excluding Boc, the monovalent organic group having a protected amino moiety selected from the group consisting of *1-NH(Boc), *1-N(Boc) ₂ and *1-N(Boc)-*1 (*1 represents a bond bonded to a carbon atom). When there are two or more protected amino moieties, the protected amino moieties may be the same or different.
[Formula 1]
Δ=|Δb−Δa|
Δ: change in rotation angle due to storage at room temperature for 48 hours Δa: rotation angle of liquid crystal cell Δb: rotation angle of liquid crystal cell using the same liquid crystal alignment agent left at room temperature for 48 hours (in the above formula 1, the rotation angle is
Two substrates with liquid crystal alignment films are used as a set. A sealant is applied onto one substrate, and the other substrate is attached so that the liquid crystal alignment film faces each other and the alignment direction is 0°. The sealant is then hardened, liquid crystal is injected, and the injection port is sealed to obtain a liquid crystal cell.
Under the illumination of a backlight of 15,000 nits, an AC voltage of ±7 V at a frequency of 60 Hz was applied for 120 hours, and then the pixel electrode and the counter electrode of the liquid crystal cell were shorted and left at room temperature for one day.
This is a value obtained by calculating the difference between the alignment direction of the liquid crystal in the first region of the pixel and the alignment direction of the liquid crystal in the second region of the pixel when no voltage is applied to the liquid crystal cell. A method for producing a liquid crystal alignment film, comprising applying the liquid crystal alignment agent according to any one of claims 1 to 10 to a substrate, baking the applied liquid crystal alignment agent, and irradiating the resulting film with polarized radiation. The method for producing a liquid crystal alignment film according to claim 11, wherein the baking temperature is 150 to 250°C. A liquid crystal alignment film formed from the liquid crystal alignment agent according to any one of claims 1 to 10. A liquid crystal display element comprising the liquid crystal alignment film according to claim 13. The liquid crystal display element according to claim 14, which is an IPS driving system or an FFS driving system.

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