WO2020080477A1

WO2020080477A1 - Liquid crystal aligning agent, liquid crystal alignment film, and liquid crystal display element using same

Info

Publication number: WO2020080477A1
Application number: PCT/JP2019/040943
Authority: WO
Inventors: 達哉名木; 貴裕須賀; 玲久小西
Original assignee: 日産化学株式会社
Priority date: 2018-10-18
Filing date: 2019-10-17
Publication date: 2020-04-23
Also published as: TW202031858A; KR20210076925A; JP7400728B2; JPWO2020080477A1; CN112912792A

Abstract

Provided is a liquid crystal aligning agent that: is capable of yielding a liquid crystal alignment film having good liquid crystal aligning properties; and has an increased sensitivity margin. The liquid crystal aligning agent is characterized by containing at least one polymer selected from the group consisting of: polyamic acids obtained by reacting a diamine component, containing a diamine having a structure represented by formula [1] below, with a tetracarboxylic acid dianhydride component; and polyimides obtained by imidizing said polyamic acids. (In formula [1], A₁ and A₂ are each independently a monocyclic group or condensed ring group optionally comprising a substituent, and A₁ and A₂ are not simultaneously monocyclic groups. X₁ and X₂ are each independently a single bond, an oxygen atom, or a sulfur atom. Q is an alkylene group comprising 1 or 2 carbon atoms. M and n are each independently integers from 1 to 3.)

Description

Liquid crystal aligning agent, liquid crystal aligning film, and liquid crystal display device using the same

The present invention relates to a liquid crystal alignment agent, a liquid crystal alignment film, and a liquid crystal display device using the same.

Currently, polyimide films are often used for liquid crystal alignment films used in liquid crystal display devices. The liquid crystal alignment film of this polyimide film is prepared by a method of applying a solution of a polyimide precursor polyamic acid or a solvent-soluble polyimide solution to a substrate and subjecting the film obtained by baking to an alignment treatment such as a rubbing treatment. ing. This polyamic acid or solvent-soluble polyimide is generally produced by a polycondensation reaction between a tetracarboxylic acid derivative such as tetracarboxylic acid dianhydride and a diamine compound.

Diamine compounds, which are raw materials such as polyamic acid and polyimide, are important because they affect the characteristics of the liquid crystal alignment film obtained therefrom, and thus the characteristics of the liquid crystal display device, and various diamine compounds have been conventionally used. Proposed.

For example, Patent Document 1 proposes a liquid crystal aligning agent obtained from the following diamine compounds.

Japanese Patent Laid-Open No. 2005-157346

However, in recent years, liquid crystal display elements have been improved in performance, area, and power consumption of display devices have been advanced. In addition, liquid crystal display elements have come to be used in various environments. The characteristics that can be obtained are becoming severe. In particular, as the use of liquid crystal display elements progresses, it becomes more difficult to secure good liquid crystal alignment, and the problem of a small sensitivity margin when forming a liquid crystal alignment film becomes significant. Here, the sensitivity margin means a sensitivity region in which good liquid crystal alignment characteristics can be obtained when polarized ultraviolet rays are irradiated.

If it becomes impossible to secure a good liquid crystal alignment, light leakage and alignment failure will occur easily. In addition, if the sensitivity margin is small, display unevenness during long-term driving and in-plane unevenness of the liquid crystal alignment direction are caused by unevenness of the illuminance of the ultraviolet irradiator, which causes light leakage and unevenness when black display is performed. Therefore, although there is a strong demand for good liquid crystal alignment and an improved sensitivity margin, the conventionally proposed technology cannot sufficiently satisfy such demand.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a liquid crystal aligning agent capable of obtaining a liquid crystal aligning film having good liquid crystal aligning property and having an increased sensitivity margin. .

As a result of intensive studies to solve the above problems, the present inventors have found that a liquid crystal aligning agent containing a polymer obtained from a novel diamine satisfies the above problems.
The present invention is based on such findings and has the following gist.
From the group consisting of a polyamic acid obtained by reacting a diamine component containing a diamine having a structure represented by the following formula [1] with a tetracarboxylic dianhydride component, and a polyimide obtained by imidizing the polyamic acid. A liquid crystal aligning agent comprising at least one polymer selected.

(In the formula [1], A ₁ and A ₂ are each independently a monocyclic group which may have a substituent or a condensed ring group, and A ₁ and A ₂ are simultaneously a monocyclic group. X ₁ and X ₂ are each independently a single bond, an oxygen atom or a sulfur atom, Q is an alkylene group having 1 or 2 carbon atoms, and m and n are each independently. And is an integer of 1 to 3.)

According to the liquid crystal aligning agent of the present invention, a liquid crystal aligning film having good liquid crystal aligning property can be obtained, and a sensitivity margin can be increased.

<Specific diamine of the present invention>
The diamine used as a raw material for the liquid crystal aligning agent of the present invention is a diamine having a structure represented by the following formula [1].

In the above formula [1], A ₁ and A ₂ are each independently a monocyclic group which may have a substituent or a condensed ring group, and A ₁ and A ₂ are simultaneously a monocyclic group. It never happens. X ₁ and X ₂ are each independently a single bond, an oxygen atom or a sulfur atom. Q is an alkylene group having 1 or 2 carbon atoms. m and n are each independently an integer of 1 to 3.

ㆍ A monocyclic group means the remaining atomic group obtained by removing two hydrogen atoms from a monocycle. Examples of the monocycle include benzene; 5-membered heterocycles such as furan, thiophene, pyrrole, oxazole, thiazole, imidazole, and pyrazole; and 6-membered heterocycles such as pyran, pyrone, pyridine, pyridazine, pyrimidine, and pyrazine. The monocycle is preferably benzene or pyridine. When the monocyclic ring is benzene, the monocyclic group is a phenylene group.

“Fused ring group” means an atomic group remaining after removing two hydrogen atoms from the condensed ring. Examples of the condensed ring include condensed polycyclic aromatic hydrocarbons such as naphthalene, tetralin, indene, fluorene, anthracene, phenanthrene, and pyrene; benzofuran, thionaphthene, indole, carbazole, coumarin, benzo-pyrone, quinoline, isoquinoline, acridine, Examples include condensed polycyclic heterocycles such as phthalazine, quinazoline, quinoxaline. The fused ring is preferably naphthylene, anthracene, pyrene, indole, carbazole, coumarin, benzo-pyrone, quinoline, or isoquinoline.

The monocyclic group and the condensed ring group may further have a substituent. Examples of the substituent that the monocyclic group and the condensed ring group may have include alkyl having 1 to 4 carbons, alkoxy having 1 to 4 carbons, halogen atom and the like.

X ₁ and X ₂ are preferably oxygen atoms. From the viewpoint of the liquid crystal alignment regulating force, Q is preferably alkylene having 2 carbon atoms. m and n are preferably 1.

Specific preferred diamines include, but are not limited to, the followings.

<Tetracarboxylic acid dianhydride component>
In order to obtain the polyimide precursor of the present invention, a tetracarboxylic dianhydride represented by the following formula [7] (also referred to as a specific tetracarboxylic dianhydride) or a derivative thereof is used as a tetracarboxylic dianhydride component. It is preferably used as a part.

In the formula [7], Z ₁ is a tetravalent organic group, and examples thereof include the structures of the following formulas (X1-1) to (X1-19).

In the formulas (X1-1) and (X1-2), R ₃ to R ₁₂ are each independently 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, or a phenyl group. However, at least one of R ₃ to R ₆ is a group other than a hydrogen atom.

From the viewpoint of liquid crystal alignment, the structure of X ₁ is preferably the above formula (X1-1), (X1-3) or (X1-4), and in the formula (X1-1), the following formula (X1-1) At least one selected from the structures represented by -1) to (X1-1-5) is more preferable, and the following formula (X1-1-1) is particularly preferable. The tetracarboxylic acid dianhydride represented by the formula [7] or a derivative thereof may be used as a mixture of two or more kinds.

The use ratio of the tetracarboxylic acid dianhydride represented by the above formula [7] or a derivative thereof is preferably 50 mol% or more based on 1 mol of the tetracarboxylic acid dianhydride component used in the polymer of the present invention, 70 mol% or more is more preferable, and 80 mol% or more is still more preferable.
Further, when the tetracarboxylic dianhydride component used in the polymerization of the polymer of the present invention contains the tetracarboxylic dianhydride represented by the above formula [7] or a derivative thereof, suppression of bright spots due to decomposition products It is preferable from the viewpoint of liquid crystal alignment.

The tetracarboxylic dianhydride component used for the polymerization of the polymer of the present invention may contain a tetracarboxylic dianhydride other than the above formula [7] or a derivative thereof.
The tetracarboxylic acid dianhydride or derivative thereof other than the above formula [7] may be used alone or in combination of two or more in consideration of the liquid crystal alignment property of the liquid crystal alignment film to be formed, the voltage holding property and the accumulated charge. Can be used.

<Polymer of the present invention>
The polymer in the present invention means a polyamic acid and / or a polyimide obtained by imidizing the polyamic acid.

<Polyamic acid>
The polyamic acid of the present invention is obtained by the reaction of a diamine component containing a specific diamine and a tetracarboxylic dianhydride component.
In the diamine component for obtaining the polyamic acid by the reaction with the tetracarboxylic acid dianhydride component, the content ratio of the specific diamine is not limited. The content of the specific diamine in the diamine component may be 100%. However, various diamines can be used in combination because they satisfy various properties required for the liquid crystal alignment film, such as a property of increasing the pretilt angle of the liquid crystal and a property of enhancing the vertical alignment property of the liquid crystal. . The content ratio of the specific diamine in the diamine component used for polymerization is preferably 1 to 50 mol%, particularly preferably 5 to 30 mol%.

In the above diamine component, as the diamine other than the specific diamine (hereinafter also referred to as other diamine) used together when the specific diamine is less than 100 mol%, alicyclic diamine, aromatic-aliphatic diamine, aromatic Examples thereof include diamine, heterocyclic diamine, and aliphatic diamine.

Examples of the alicyclic diamine include 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, 4,4′-diaminodicyclohexylmethane, 4,4′-diamino-3,3′-dimethyldicyclohexylamine and isophoronediamine. Etc.
Examples of aromatic diamines include o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 2,4-diaminotoluene, 2,5-diaminotoluene, 3,5-diaminotoluene, 1,4-diamino. -2-methoxybenzene, 2,5-diamino-p-xylene, 1,3-diamino-4-chlorobenzene, 3,5-diaminobenzoic acid, 1,4-diamino-2,5-dichlorobenzene, 4,4 '-Diamino-1,2-diphenylethane, 4,4'-diamino-2,2'-dimethylbibenzyl, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane , 4,4'-diamino-3,3'-dimethyldiphenylmethane, 2,2'-diaminostilbene, 4,4'-diaminostilbene, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminobenzophenone 1,3-bis (3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 3,5-bis (4-aminophenoxy) ) Benzoic acid, 4,4'-bis (4-aminophenoxy) bibenzyl, 2,2-bis [(4-aminophenoxy) methyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] Hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, bis [4- (3-aminophen) Enoxy) phenyl] sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, 1,1-bis (4-aminophenyl) cyclohexane, α, α′-bis (4-aminophenyl) -1,4- Diisopropylbenzene, 9,9-bis (4-aminophenyl) fluorene, 2,2-bis (3-aminophenyl) hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4 ' -Diaminodiphenylamine, 2,4-diaminodiphenylamine, 1,8-diaminonaphthalene, 1,5-diaminonaphthalene, 1,5-diaminoanthraquinone, 1,3-diaminopyrene, 1,6-diaminopyrene, 1,8- Diaminopyrene, 2,7-diaminofluorene, 1,3-bis (4-aminophenyl) tetramethyldisi Xanthane, benzidine, 2,2'-dimethylbenzidine, 1,2-bis (4-aminophenyl) ethane, 1,3-bis (4-aminophenyl) propane, 1,4-bis (4-aminophenyl) butane 1,5-bis (4-aminophenyl) pentane, 1,6-bis (4-aminophenyl) hexane, 1,7-bis (4-aminophenyl) heptane, 1,8-bis (4-aminophenyl) ) Octane, 1,9-bis (4-aminophenyl) nonane, 1,10-bis (4-aminophenyl) decane, 1,3-bis (4-aminophenoxy) propane, 1,4-bis (4- Aminophenoxy) butane, 1,5-bis (4-aminophenoxy) pentane, 1,6-bis (4-aminophenoxy) hexane, 1,7-bis (4-aminophenoxy) heptane 1,8-bis (4-aminophenoxy) octane, 1,9-bis (4-aminophenoxy) nonane, 1,10-bis (4-aminophenoxy) decane, di (4-aminophenyl) propane-1, 3-dioate, di (4-aminophenyl) butane-1,4-dioate, di (4-aminophenyl) pentane-1,5-dioate, di (4-aminophenyl) hexane-1,6-dioate, di (4-aminophenyl) heptane-1,7-dioate, di (4-aminophenyl) octane-1,8-dioate, di (4-aminophenyl) nonane-1,9-dioate, di (4-aminophenyl) ) Decane-1,10-dioate, 1,3-bis [4- (4-aminophenoxy) phenoxy] propane, 1,4-bis [4- (4-aminopheno) Si) phenoxy] butane, 1,5-bis [4- (4-aminophenoxy) phenoxy] pentane, 1,6-bis [4- (4-aminophenoxy) phenoxy] hexane, 1,7-bis [4- (4-Aminophenoxy) phenoxy] heptane, 1,8-bis [4- (4-aminophenoxy) phenoxy] octane, 1,9-bis [4- (4-aminophenoxy) phenoxy] nonane, 1,10- Examples thereof include bis [4- (4-aminophenoxy) phenoxy] decane.

Examples of aromatic-aliphatic diamines include 3-aminobenzylamine, 4-aminobenzylamine, 3-amino-N-methylbenzylamine, 4-amino-N-methylbenzylamine, 3-aminophenethylamine, 4- Aminophenethylamine, 3-amino-N-methylphenethylamine, 4-amino-N-methylphenethylamine, 3- (3-aminopropyl) aniline, 4- (3-aminopropyl) aniline, 3- (3-methylaminopropyl) Aniline, 4- (3-methylaminopropyl) aniline, 3- (4-aminobutyl) aniline, 4- (4-aminobutyl) aniline, 3- (4-methylaminobutyl) aniline, 4- (4-methyl Aminobutyl) aniline, 3- (5-aminopentyl) aniline, 4- (5-aminopentyl Aniline, 3- (5-methylaminopentyl) aniline, 4- (5-methylaminopentyl) aniline, 2- (6-aminonaphthyl) methylamine, 3- (6-aminonaphthyl) methylamine, 2- (6 -Aminonaphthyl) ethylamine, 3- (6-aminonaphthyl) ethylamine and the like can be mentioned.

Examples of the heterocyclic diamine include 2,6-diaminopyridine, 2,4-diaminopyridine, 2,4-diamino-1,3,5-triazine, 2,7-diaminodibenzofuran and 3,6-diaminocarbazole. , 2,4-diamino-6-isopropyl-1,3,5-triazine, 2,5-bis (4-aminophenyl) -1,3,4-oxadiazole and the like.
Examples of the aliphatic diamine include 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,3-diamino-2,2-dimethylpropane, 1,6-diamino-2,5-dimethylhexane, 1,7- Diamino-2,5-dimethylheptane, 1,7-diamino-4,4-dimethylheptane, 1,7-diamino-3-methylheptane, 1,9-diamino-5-methylnonane, 1,12-diaminododecane, Examples include 1,18-diaminooctadecane and 1,2-bis (3-aminopropoxy) ethane.

You may use together the diamine which has an alkyl group, a fluorine-containing alkyl group, an aromatic ring, an aliphatic ring, a heterocycle, or the macrocyclic substitution body which consists of them in a side chain. Specifically, diamines represented by the following formulas [DA-101] to [DA-130] are exemplified.

(R ₆ is an alkyl group or a fluorine-containing alkyl group having 1 to 22 carbon atoms.)

(S ₅ is —COO—, —OCO—, —CONH—, —NHCO—, —CH ₂ —, —O—, —CO—, or NH—, and R ₆ has 1 to 22 carbon atoms. , An alkyl group or a fluorine-containing alkyl group.)

(S ₆ is —O—, —OCH ₂ —, —CH ₂ O—, —COOCH ₂ —, or CH ₂ OCO—, and R ₇ is an alkyl group, an alkoxy group, having 1 to 22 carbon atoms, It is a fluorine-containing alkyl group or a fluorine-containing alkoxy group.)

(S ₇ is —COO—, —OCO—, —CONH—, —NHCO—, —COOCH ₂ —, —CH ₂ OCO—, —CH ₂ O—, —OCH ₂ —, or CH ₂ —, R ₈ is an alkyl group, an alkoxy group, a fluorine-containing alkyl group or a fluorine-containing alkoxy group having 1 to 22 carbon atoms.)

(S ₈ is —COO—, —OCO—, —CONH—, —NHCO—, —COOCH ₂ —, —CH ₂ OCO—, —CH ₂ O—, —OCH ₂ —, —CH ₂ —, —O -Or NH-, and R ₉ is a fluorine group, a cyano group, a trifluoromethane group, a nitro group, an azo group, a formyl group, an acetyl group, an acetoxy group, or a hydroxyl group.)

(R ₁₀ is an alkyl group having 3 to 12 carbon atoms, and the cis-trans isomerism of 1,4-cyclohexylene is in the trans form.)

In the case of aligning with light, it is preferable to use a specific diamine in combination with the above-mentioned [DA-101] to [DA-130] because a more stable pretilt angle can be obtained. As more preferred diamines that can be used in combination, the diamines of the formulas [DA-110] to [DA-130] are preferred, and the diamines of [DA-110] to [DA-116] are more preferred. The preferred content of these diamines is not particularly limited, but is preferably 5 to 50 mol% in the diamine component, and 5 to 30 mol% in terms of printability.
Further, diamines represented by the following formulas [DA-131] to [DA-138] may be used in combination.

(M is an integer of 0 to 3, and n is an integer of 1 to 5 in the formula [DA-138]).

By containing a diamine of the formula [DA-131] or the formula [DA-132], it is possible to improve the voltage holding property when used as a liquid crystal alignment film, and to formula [DA-133] to [DA-138]. ] Diamine is effective in reducing accumulated electrification.

Furthermore, diaminosiloxane represented by the following formula [DA-139] and the like can also be mentioned as other diamines.

(M is an integer of 1 to 10.)

Furthermore, the diamine represented by the following formula (8) can also be mentioned as another diamine.

(In the formula (8), Y ₂ is a divalent organic group having a nitrogen atom bonded to the aromatic group or a nitrogen-containing aromatic heterocycle.)

Examples of Y ₂ in the formula (8) include the following formulas (Y2-1) to (Y2-12).

Other diamines may be used alone or in combination of two or more depending on properties such as liquid crystal alignment property when the liquid crystal alignment film is formed, voltage holding property and accumulated charge.

<Production of polyamic acid>
As a method for obtaining the polyamic acid of the present invention by reacting a tetracarboxylic dianhydride component and a diamine component, a known method can be used. For example, it is a method of reacting a tetracarboxylic dianhydride component and a diamine component in an organic solvent. In this case, the reaction between the tetracarboxylic acid dianhydride component and the diamine proceeds in an organic solvent relatively easily, and no by-product is generated, which is advantageous.

The organic solvent used for the reaction between the tetracarboxylic dianhydride component and the diamine is not limited as long as it can dissolve the generated polyamic acid. Specific examples are given below.
N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-methylcaprolactam, dimethylsulfoxide, tetramethylurea, pyridine, dimethylsulfone, γ-butyrolactone , Isopropyl alcohol, methoxymethyl pentanol, dipentene, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl Carbitol, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether Propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol tert-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether , Dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether , 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, dioxane, n-hexane, n -Pentane, n-octane, diethyl ether, cyclohexanone, ethylene carbonate, propylene carbonate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, Methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropione , Propyl 3-methoxypropionate, butyl 3-methoxypropionate, diglyme, 4-hydroxy-4-methyl-2-pentanone, 3-methoxy-N, N-dimethylpropanamide, 3-ethoxy-N, N-dimethyl Examples include propanamide and 3-butoxy-N, N-dimethylpropanamide. These may be used alone or in combination. Furthermore, even a solvent that does not dissolve the polyamic acid may be used as a mixture with the above solvent as long as the generated polyamic acid does not precipitate.

Further, since water in the organic solvent inhibits the polymerization reaction and causes hydrolysis of the generated polyamic acid, the organic solvent is preferably dehydrated and dried.
When the tetracarboxylic acid dianhydride component and the diamine component are reacted in an organic solvent, the solution in which the diamine component is dispersed or dissolved in the organic solvent is stirred, and the tetracarboxylic acid dianhydride component as it is, or the organic solvent A method of adding by dispersing or dissolving in a solvent, a method of adding a diamine component to a solution in which a tetracarboxylic acid dianhydride component is dispersed or dissolved in an organic solvent, a tetracarboxylic acid dianhydride component and a diamine component are added. Examples of the method include alternate addition, and any of these methods may be used. Further, when the tetracarboxylic dianhydride component or the diamine component is composed of a plurality of types of compounds, they may be reacted in a premixed state, may be individually and sequentially reacted, and are further reacted individually to have a low molecular weight. A high molecular weight body may be obtained by mixing and reacting the bodies.

The temperature at which the tetracarboxylic acid dianhydride component and the diamine component are reacted can be selected from any temperature of -20 to 150 ° C, but is preferably in the range of -5 to 100 ° C. The reaction can be carried out at any concentration, but if the concentration is too low, it becomes difficult to obtain a high-molecular weight polymer, and if the concentration is too high, the viscosity of the reaction solution becomes too high and uniform stirring is difficult. Therefore, the total concentration of the tetracarboxylic dianhydride component and the diamine component in the reaction solution is preferably 1 to 50% by mass, more preferably 5 to 30% by mass. The reaction can be performed at a high concentration in the initial stage, and then an organic solvent can be added.
In the polymerization reaction of the polyamic acid, the ratio of the total number of moles of the tetracarboxylic dianhydride component to the total number of moles of the diamine component is preferably 0.8 to 1.2, and 0.9 to 1. 1 is more preferable. Similar to the ordinary polycondensation reaction, the closer the molar ratio is to 1.0, the larger the molecular weight of the polyamic acid produced.

<Polyimide>
The polyimide of the present invention is a polyimide obtained by dehydrating and ring-closing the above polyamic acid, and is useful as a polymer for obtaining a liquid crystal alignment film.
In the polyimide of the present invention, the dehydration ring closure rate (imidization rate) of the amic acid group does not necessarily have to be 100%, and can be arbitrarily adjusted according to the application and purpose.
Examples of the method for imidizing the polyamic acid include a thermal imidization method in which a solution of the polyamic acid is heated as it is, and a catalytic imidization method in which a catalyst is added to the solution of the polyamic acid.
The temperature at which the polyamic acid is subjected to thermal imidization in a solution is 100 to 400 ° C., preferably 120 to 250 ° C., and it is preferable to remove water generated by the imidization reaction outside the system.

The catalytic imidization of polyamic acid can be carried out by adding a basic catalyst and an acid anhydride to a solution of polyamic acid and stirring the mixture at -20 to 250 ° C, preferably 0 to 180 ° C. The amount of the basic catalyst is 0.5 to 30 times, preferably 2 to 20 times the amount of the amic acid group, and the amount of the acid anhydride is 1 to 50 times, preferably 3 to the molar amount of the amic acid group. It is 30 mol times. Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine and the like. Among them, pyridine is preferable because it has a basicity suitable for proceeding the reaction. Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, pyromellitic dianhydride, and the use of acetic anhydride is preferable because purification after the reaction is easy. The imidization rate by catalytic imidization can be controlled by adjusting the amount of catalyst, reaction temperature, reaction time, and the like.

The molecular weight of the polymer contained in the liquid crystal aligning agent of the present invention is determined by GPC (Gel Permeation Chromatography) method in consideration of the strength of the obtained coating film, the workability during coating film formation, and the uniformity of the coating film. The measured weight average molecular weight is preferably 5,000 to 1,000,000, and more preferably 10,000 to 150,000.

<Liquid crystal aligning agent>
The liquid crystal aligning agent of the present invention is a coating liquid for forming a liquid crystal aligning film, and is a solution in which a resin component for forming a resin film is dissolved in an organic solvent. Here, the resin component contains at least one polymer selected from the above-mentioned polymers of the present invention. The content of the resin component in the liquid crystal aligning agent is preferably 1 to 20% by mass, more preferably 3 to 15% by mass, and particularly preferably 3 to 10% by mass.
All of the resin components may be the polymer of the present invention, or other polymers may be mixed. At that time, the content of the other polymer in the resin component is 0.5 to 15% by mass, preferably 1 to 10% by mass.
Examples of such other polymer include polyamic acid or polyimide obtained by using a diamine compound other than the specific diamine compound as the diamine component to be reacted with the tetracarboxylic dianhydride component.

The organic solvent used for the liquid crystal aligning agent of the present invention is not particularly limited as long as it is an organic solvent that dissolves the resin component. Specific examples are given below.
N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 2-pyrrolidone, N-ethylpyrrolidone, N-vinylpyrrolidone, dimethylsulfoxide, tetramethylurea, pyridine, Dimethyl sulfone, hexamethyl sulfoxide, γ-butyrolactone, 3-methoxy-N, N-dimethylpropanamide, 3-ethoxy-N, N-dimethylpropanamide, 3-butoxy-N, N-dimethylpropanamide, 1,3 -Dimethyl-imidazolidinone, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, cyclohexanone, ethylene carbonate, propylene carbonate, diglyme, 4-hydroxy-4 Such as methyl-2-pentanone and the like. These may be used alone or in combination.

The liquid crystal aligning agent of the present invention may contain components other than the above. Examples thereof include compounds that improve the adhesion between the liquid crystal alignment film and the substrate, such as solvent-rich substances that improve the film thickness uniformity and surface smoothness when the liquid crystal alignment agent is applied.
Specific examples of the solvent (poor solvent) that improves the uniformity of the film thickness and the surface smoothness include the following.

For example, isopropyl alcohol, methoxymethyl pentanol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethyl carbitol acetate, ethylene glycol, ethylene glycol monoacetate, ethylene glycol mono Isopropyl ether, ethylene glycol monobutyl ether, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol-tert-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, dipro Len glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, dipropylene glycol dimethyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene , Propyl ether, dihexyl ether, 1-hexanol, -Hexane, n-pentane, n-octane, diethyl ether, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, 3-methoxy Methyl propionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, 1-methoxy-2 -Propanol, 1-ethoxy-2-propanol, 1-butoxy-2-propanol, 2-butoxy-1-propanol, 2,6-dimethyl-4-heptanol, 1-phenoxy-2-propanol, propylene glycol monoacetate, propylene Glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether-2-acetate, dipropylene glycol, 2- (2-ethoxypropoxy) propanol, lactic acid methyl ester, lactic acid ethyl ester , Lactate n-propyl ester, lactate n-butyl ester, lactate isoamyl ester, and other solvents having a low surface tension.
These poor solvents may be used alone or in combination of two or more. When the above solvent is used, it is preferably 5 to 80% by mass, and more preferably 20 to 60% by mass, based on the whole solvent contained in the liquid crystal aligning agent.

Examples of the compound that improves the uniformity of the film thickness and the surface smoothness include a fluorine-based surfactant, a silicone-based surfactant, and a nonion-based surfactant.
More specifically, for example, Ftop EF301, EF303, EF352 (manufactured by Tochem Products), Megafac F171, F173, R-30 (manufactured by Dainippon Ink and Chemicals), Fluorard FC430, FC431 (manufactured by Sumitomo 3M) Asahi Guard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by Asahi Glass Co., Ltd.). The use ratio of these surfactants is preferably 0.01 to 2 parts by mass, more preferably 0.01 to 1 part by mass, relative to 100 parts by mass of the resin component contained in the liquid crystal aligning agent.

Specific examples of the compound that improves the adhesion between the liquid crystal alignment film and the substrate include functional silane-containing compounds and epoxy group-containing compounds shown below.
For example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane , N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxy Carbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-to Ethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyltri Methoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3-amino Propyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, 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, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetra Glycidyl-2,4-hexanediol, N, N, N ', N',-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N Examples include ', N',-tetraglycidyl-4,4'-diaminodiphenylmethane and the like.

Furthermore, in addition to improving the adhesion between the substrate and the film, it is preferable to contain the following phenoplast-based additive for the purpose of preventing the deterioration of the electrical characteristics due to the backlight. Specific phenoplast additives are shown below.

When a compound that improves the adhesion to the substrate is used, its amount is preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass, relative to 100 parts by mass of the resin component. is there. If the amount used is less than 0.1 parts by mass, the effect of improving the adhesiveness cannot be expected, and if it exceeds 30 parts by mass, the orientation of the liquid crystal may deteriorate.
In addition to the above, the liquid crystal aligning agent of the present invention contains a dielectric substance, a conductive substance, and further a film of a liquid crystal alignment film when it is formed into a liquid crystal alignment film for the purpose of changing electrical properties such as dielectric constant and conductivity. A crosslinkable compound or the like for the purpose of increasing hardness or compactness may be added.

<Liquid crystal alignment film and liquid crystal display element>
The liquid crystal aligning agent of the present invention can be used as a liquid crystal aligning film without applying alignment treatment such as rubbing treatment or light irradiation after being applied on a substrate and baked, or for vertical alignment use. At this time, the substrate used is not particularly limited as long as it is a highly transparent substrate, and a glass substrate, an acrylic substrate, a plastic substrate such as a polycarbonate substrate, or the like can be used. Further, it is preferable to use a substrate on which an ITO electrode or the like for driving the liquid crystal is formed in terms of simplification of the process. Further, in the reflection type liquid crystal display element, an opaque material such as a silicon wafer can be used as long as it is only on one side of the substrate, and in this case, a material such as aluminum that reflects light can be used as the electrode.
The method for applying the liquid crystal aligning agent is not particularly limited, but industrially, it is generally performed by a method such as screen printing, offset printing, flexographic printing, and inkjet. Other coating methods include dips, roll coaters, slit coaters, spinners and the like, and these may be used depending on the purpose.

Firing after applying the liquid crystal aligning agent on the substrate is performed at 50 to 300 ° C., preferably 80 to 250 ° C. by a heating means such as a hot plate, and the solvent can be evaporated to form a coating film. If the thickness of the coating film formed after firing is too thick, it is disadvantageous in terms of power consumption of the liquid crystal display element, and if it is too thin, the reliability of the liquid crystal display element may decrease, so that the thickness is preferably 5 to 300 nm. It is preferably 10 to 100 nm. When the liquid crystal is horizontally or tilted, the baked coating film is treated by rubbing or irradiation with polarized ultraviolet light.
The method for aligning a liquid crystal alignment film obtained from the liquid crystal aligning agent of the present invention may be a rubbing treatment method, but the liquid crystal aligning agent of the present invention can obtain an alignment treatment with an expanded dose margin as described above. Therefore, the photo-alignment treatment method is preferable. As a preferred example of the photo-alignment treatment method, radiation having a wavelength of 100 to 800 nm, preferably ultraviolet light or visible light, can be used on the surface of the liquid crystal alignment film. Among them, ultraviolet rays having a wavelength of preferably 100 to 400 nm, more preferably 200 to 400 nm are used.
Light irradiation amount in the photo-alignment treatment method, 1 preferably ~ 10,000 / cm ^2, more preferably 100 ~ 5,000mJ / cm ² Of these, particularly preferably 100 ~ 2000mJ / cm ^2.
The liquid crystal display device of the present invention is a liquid crystal display device in which a liquid crystal alignment film-provided substrate is obtained from the liquid crystal alignment agent of the present invention by the above-mentioned method and then a liquid crystal cell is produced by a known method.

To give an example of liquid crystal cell production, prepare a pair of substrates on which a liquid crystal alignment film is formed, disperse spacers on the liquid crystal alignment film on one of the substrates, and place the liquid crystal alignment film surface inside. Examples include a method in which the other substrate is bonded and liquid crystal is injected under reduced pressure for sealing, or a method in which liquid crystal is dropped on the surface of the liquid crystal alignment film on which spacers are dispersed and then the substrate is bonded and sealed. The thickness of the spacer is preferably 1 to 30 μm, more preferably 2 to 10 μm. ――

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto. The abbreviations of the compounds and the measuring methods of the respective properties below are as follows.
NMP: N-methyl-2-pyrrolidone, GBL: γ-butyrolactone,
BCS: butyl cellosolve,

1. Synthesis Example of Compound [DA-3] Compound [DA-3] was synthesized according to the following scheme.

Synthesis of Compound [1] 6-Bromonaphthalen-2-ol (150 g, 672 mmol) was added to dimethylformamide (1050 g), and the mixture was cooled under ice cooling. On the other hand, sodium hydride (60%, 29.6 g) was added little by little, the mixture was stirred under ice cooling for 1 hour, benzyl bromide (121 g) was added, and the mixture was stirred at room temperature for 1 hour. Further, under water cooling, pure water (750 g) was added little by little and stirred to precipitate crystals. The obtained crystal-containing liquid was filtered, the residue was slurry-washed with methanol (750 g), filtered, and the residue was dried to obtain compound [1] (yield: 207 g, yield: 98%, White crystals).
1H-NMR (400MHz, DMSO-d6, δppm): 8.13 (d, 1H, J = 2.0 Hz), 7.85 (d, 1H, J = 9.2 Hz), 7.78 (d, 1H, J = 8.8 Hz), 7.58 (dd, 1H, J = 8.8 Hz, 2.4Hz), 7.53-7.48 (m, 3H), 7.44-7.40 (m, 2H), 7.38-7.33 (m, 1H), 7.30 (dd, 1H, J = 9.0 Hz, 2.6 Hz), 5.22 (s, 2H).

Synthesis of Compound [2] To tetrahydrofuran (1000 g), tert-butoxy sodium (82.6 g) and benzophenone imine (126 g) were added, and the mixture was stirred at room temperature for 30 minutes. To this, compound [1] (207 g, 661 mmol), Pd ₂ (dba) ₃ (3.03 g) and BINAP (6.17 g) were added, and the mixture was stirred at 65 ° C. for 23 hours under a nitrogen atmosphere. After cooling to room temperature, 1N hydrochloric acid (1000 g) was added, the mixture was stirred at room temperature for 15 minutes, and the aqueous layer was separated. Further, ethyl acetate (200 g), hexane (100 g) and 1N hydrochloric acid (500 g) were added to the organic layer and added to the separated aqueous layer. Under water cooling, sodium hydroxide (80 g) was added to make it alkaline. The organic layer was separated, washed with saturated aqueous sodium chloride solution, dried over sodium sulfate, filtered, and the filtrate was concentrated to obtain a crude product (154 g). Ethyl acetate (462 g) was added to the crude product and the mixture was heated and dissolved at 70 ° C., hexane (770 g) was added, and the mixture was cooled. Then, the mixture was filtered and the residue was dried to obtain the compound [2] (yield: 124 g, yield: 74%, light brown crystal).
1H-NMR (400MHz, DMSO-d6, δppm): 7.50-7.43 (m, 4H), 7.42-7.37 (m, 2H), 7.35-7.30 (m, 1H), 7.19 (d, 1H, J = 2.8 Hz ), 7.04 (dd, 1H, J = 8.8 Hz, 2.8 Hz), 6.90 (dd, 1H, J = 8.8 Hz, 2.0 Hz), 6.80 (d, 1H, J = 2.0 Hz), 5.13 (br, 4H) .

Synthesis of Compound [3] Compound [2] (124 g, 497 mmol) and di-tert-butyl dicarbonate (130 g) were added to dichloromethane (1000 g), and the mixture was stirred at room temperature for 20 hours. Since the reaction was not completed, additional di-tert-butyl dicarbonate (10 g) was added, and the mixture was further stirred at room temperature for 20 hours. A saturated aqueous sodium hydrogencarbonate solution (1000 mL) and dichloromethane (300 g) were added, and the layers were separated. The organic layer was washed with pure water (450 mL) and saturated aqueous sodium chloride solution (300 mL) in this order, dried over sodium sulfate, filtered, and the filtrate was concentrated to obtain a crude product (198 g). Ethyl acetate (600 g) was added to the crude product, and the mixture was heated and dissolved at 70 ° C., hexane (1000 g) was added, and the mixture was cooled. Then, the mixture was filtered and the residue was dried to obtain the compound [3] (yield: 142 g, yield: 82%, white crystals).
1H-NMR (400MHz, DMSO-d6, δppm): 9.46 (s, 1H), 8.02 (s, 1H), 7.69 (t, 2H, J = 8.6Hz), 7.52-7.49 (m, 2H), 7.45 ( dd, 1H, J = 9.0 Hz, 2.2 Hz), 7.43-7.39 (m, 2H), 7.37-7.32 (m, 2H), 7.17 (dd, 1H, J = 9.0 Hz, 2.6 Hz), 5.18 (s, 2H), 1.50 (s, 9H).

Synthesis of Compound [4] Compound [3] (122 g, 349 mmol) and 5% palladium carbon (12.2 g) were added to ethanol (976 g), and the mixture was stirred at 40 ° C. for 96 hours under a hydrogen atmosphere. The catalyst was filtered off from the resulting stirred liquid, and the filtrate was concentrated to obtain compound [4] (yield: 89.3 g, yield: 99%, white crystals).
1H-NMR (400MHz, DMSO-d6, δppm): 9.52 (s, 1H), 9.37 (s, 1H), 7.94 (s, 1H), 7.62-7.59 (m, 1H), 7.56 (d, 1H, J = 9.2 Hz), 7.39 (dd, 1H, J = 9.0 Hz, 2.2 Hz), 7.04-7.00 (m, 2H), 1.50 (s, 9H).

Synthesis of Compound [5] 4-Chloronitrobenzene (100 g, 635 mmol), ethylene glycol (551 g) and sodium hydroxide (23.1 g) were added to dimethyl sulfoxide (500 g), and the mixture was stirred at 100 ° C. for 19 hours. After cooling to room temperature, ethyl acetate (560 g) and pure water (700 g) were added and the layers were separated. After collecting the upper layer, ethyl acetate (300 g) was added to the lower layer to separate the layers, and the upper layers were combined. Pure water (400 g) and saturated aqueous sodium chloride solution (200 g) were added to the combined upper layers, and the layers were separated again. The ethyl acetate layer was dried over sodium sulfate, filtered, and the filtrate was concentrated to obtain a crude product ( 110 g). Ethyl acetate (330 g) was added to the crude product and the mixture was heated and dissolved at 60 ° C., hexane (550 g) was added, and the mixture was cooled. Then, the obtained liquid was filtered, and the residue was dried to obtain compound [5] (yield: 64.2 g, yield: 55%, pale yellow crystal).
1H-NMR (400MHz, DMSO-d6, δppm): 8.21 (d, 2H, J = 9.4Hz), 7.16 (d, 2H, J = 9.4Hz), 4.97 (t, 1H, J = 5.6Hz), 4.15 (t, 2H, J = 4.8 Hz), 3.77-3.73 (m, 2H).

Synthesis of Compound [6] Compound [5] (63.2 g, 345 mmol) was added to dichloromethane (1264 g), and the mixture was cooled under ice cooling. To this, triethylamine (52.4 g), tosyl chloride (69.0 g) and 4-dimethylaminopyridine (1.26 g) were added, and the mixture was stirred at room temperature for 19 hours. Pure water (632 g) was added, and liquid separation was performed to collect a dichloromethane layer, and 1N hydrochloric acid (300 g), pure water (300 g), and saturated sodium chloride aqueous solution (300 g) were sequentially separated and washed, and dried over anhydrous sodium sulfate. The mixture was filtered, and the filtrate was concentrated to obtain compound [6] (yield: 108 g, yield: 93%, white crystals).
1H-NMR (400MHz, DMSO-d6, δppm): 8.18 (d, 2H, J = 9.2 Hz), 7.80 (d, 2H, J = 8.6 Hz), 7.47 (d, 2H, J = 8.6 Hz), 7.05 (d, 2H, J = 9.2 Hz), 4.40-4.37 (m, 2H), 4.35-4.31 (m, 2H), 2.41 (s, 3H).

Synthesis of compound [7] To dimethylformamide (360 g), compound [4] (45.0 g, 174 mmol), compound [6] (61.5 g) and potassium carbonate (36.0 g) were added, and the mixture was heated at 80 ° C. Stir for 21 hours. After cooling to room temperature, pure water (720 g) was added to precipitate crystals. The resulting crystal-containing liquid was filtered, the residue was washed with methanol (360 g) in a slurry, filtered, and the residue was dried to obtain compound [7] (yield: 67.2 g, yield: 91). %, Pale ocher crystals).
1H-NMR (400MHz, DMSO-d6, δppm): 9.47 (s, 1H), 8.23 (d, 2H, J = 9.2 Hz), 8.02 (s, 1H), 7.72-7.69 (m, 2H), 7.46 ( dd, 1H, J = 8.8 Hz, 2.0 Hz), 7.31 (d, 1H, J = 2.4 Hz), 7.24 (d, 2H, J = 9.2 Hz), 7.14 (dd, 1H, J = 9.0 Hz, 2.6 Hz ), 4.56-4.53 (m, 2H), 4.46-4.43 (m, 2H), 1.50 (s, 9H).

Synthesis of Compound [8] To chloroform (1096 g), compound [7] (73.1 g, 172 mmol) was added, and trifluoroacetic acid (98.1 g) was added with stirring under water cooling, and at 50 ° C. Stir for 19 hours. The resulting stirred liquid was cooled to room temperature, and triethylamine (87.0 g) and pure water (1096 g) were added to precipitate crystals. The obtained crystal-containing liquid was filtered, and the residue was washed with a slurry of methanol (365 g), filtered, and the residue was dried to obtain a crude product (49.5 g). Dimethylformamide (124 g) was added to the crude product, and the mixture was heated and dissolved at 80 ° C., then methanol (248 g) was added and cooled to precipitate crystals. The liquid containing the obtained crystals was filtered, and the residue was dried to obtain compound [8] (yield: 47.3 g, yield: 85%, orange crystal).
1H-NMR (400MHz, DMSO-d6, δppm): 8.23 (d, 2H, J = 9.2 Hz), 7.51 (dd, 1H, J = 8.8 Hz, 2.4 Hz), 7.45 (dd, 1H, J = 8.8 Hz) , 2.4 Hz), 7.24 (dd, 2H, J = 9.2 Hz, 2.4 Hz), 7.27 (s, 1H), 7.01 (d, 1H, J = 9.2 Hz), 6.91 (d, 1H, J = 8.8 Hz) , 6.80 (s, 1H), 5.15 (br, 2H), 4.55-4.51 (m, 2H), 4.41-4.37 (m, 2H).

Synthesis of Compound [DA-3] Compound [8] (46.4 g, 143 mmol) and 5% palladium carbon (4.6 g) were added to dimethylformamide (371 g), and the mixture was heated in a hydrogen atmosphere at 60 ° C. for 19 hours. It was stirred. Since the reaction did not proceed so much, the mixture was stirred in an autoclave under a hydrogen atmosphere of 0.4 MPa at 60 ° C. for 8 hours. After substituting with nitrogen, the catalyst was filtered off and the filtrate was concentrated to a content of 80 g. Dimethylformamide (46 g) was added and the mixture was heated and dissolved at 90 ° C., then methanol (210 g) was added and cooled to precipitate crystals. Then, the obtained crystal-containing liquid was filtered, and the residue was dried to obtain compound [DA-3] (yield: 33.4 g, yield: 79%, light purple crystals).
1H-NMR (400MHz, DMSO-d6, δppm): 7.50 (d, 1H, J = 8.8 Hz), 7.44 (d, 1H, J = 8.8 Hz), 7.13 (d, 1H, J = 2.8 Hz), 7.00 (dd, 1H, J = 8.8 Hz, 2.8 Hz), 6.90 (dd, 1H, J = 8.8 Hz, 2.4 Hz), 6.79 (d, 1H, J = 2.4 Hz), 6.71 (d, 2H, J = 8.8 Hz), 6.52 (d, 2H, J = 8.8 Hz), 5.13 (br, 2H), 4.63 (br, 2H), 4.28-4.25 (m, 2H), 4.20-4.17 (m, 2H).

2. Synthesis Example of Compound [DA-4] Compound [DA-4] was synthesized according to the following scheme.

Synthesis of Compound [4] Compound [4], which is a synthetic intermediate for Compound [3], was used.

Synthesis of Compound [9] Ethylene glycol ditosylate (60.7 g, 164 mmol), compound [4] (89.3 g) and potassium carbonate (56.7 g) were added to dimethylformamide (607 g), and the mixture was heated at 80 ° C. for 22 hours. It was stirred. After cooling the stirred liquid to room temperature, pure water (1200 g) was added to precipitate crystals. Then, the liquid containing the obtained crystals was filtered, the residue was washed with methanol (450 g) in a slurry, filtered, and the residue was dried to obtain a crude product (83.9 g). Dimethylformamide (839 g) was added to the crude product, and the mixture was heated and dissolved at 90 ° C., then methanol (839 g) was added and cooled to precipitate crystals. The liquid containing the obtained crystals was filtered, and the residue was dried to obtain compound [9] (yield: 71.2 g, yield: 80%, orange crystal).
1H-NMR (400MHz, DMSO-d6, δppm): 9.43 (s, 2H), 7.99 (br, 2H), 7.67 (d, 4H, J = 8.8 Hz), 7.43 (dd, 2H, J = 8.8 Hz, 2.4 Hz), 7.28 (d, 2H, J = 2.4 Hz), 7.12 (dd, 2H, J = 8.8Hz, 2.4 Hz), 4.42 (s, 4H), 1.47 (s, 18H).

Synthesis of Compound [DA-4] Compound [9] (71.2 g, 129 mmol) was added to chloroform (1143 g), and the mixture was cooled under water cooling. Trifluoroacetic acid (160 g) was added thereto, and the mixture was stirred at 50 ° C. for 24 hours. After cooling to room temperature, triethylamine (142 g) and pure water (1143 g) were added to precipitate crystals. Then, the liquid containing the obtained crystals was filtered, the residue was washed with methanol (400 g) in a slurry, filtered, and the residue was dried to obtain a crude product (37.5 g). Dimethylformamide (225 g) was added to the crude product, and the mixture was heated and dissolved at 90 ° C., then methanol (225 g) was added and cooled to precipitate crystals. The liquid containing the obtained crystals was filtered, and the residue was dried to obtain compound [DA-4] (yield: 33.5 g, yield: 75%, pale reddish purple crystals).
1H-NMR (400MHz, DMSO-d6, δppm): 7.51 (d, 2H, J = 8.8 Hz), 7.45 (d, 2H, J = 8.8 Hz), 7.17 (d, 2H, J = 2.4 Hz), 7.02 (dd, 2H, J = 8.8 Hz, 2.4 Hz), 6.91 (dd, 2H, J = 8.8Hz, 2.4 Hz), 6.80 (d, 2H, J = 2.4 Hz), 5.14 (br, 4H), 4.37 ( s, 4H).

3. Synthesis Example of Compound [DA-5] Compound [DA-5] was synthesized according to the following scheme.

Synthesis of Compound [10] 4-Hydroxy-4′-nitrobiphenyl (5.00 g, 23.2 mmol) and potassium carbonate (8.02 g) were added to dimethylformamide (35 g), and the mixture was stirred at 80 ° C. for 30 minutes. A solution of 2-bromoethanol (4.35 g) in dimethylformamide (5 g) was added thereto, and the mixture was stirred at 100 ° C for 16 hours. After cooling to room temperature, pure water (80 g) was added and stirred, and the precipitate was filtered off. The residue was washed with a slurry of methanol (35 g), filtered, and the residue was dried to obtain compound [10] (yield: 4.35 g, yield: 72%, yellow crystals).
1H-NMR (400MHz, DMSO-d6, δppm): 8.27 (d, 2H, J = 7.2Hz), 7.92 (d, 2H, J = 7.2Hz), 7.76 (d, 2H, J = 6.8Hz), 7.09 (d, 2H, J = 6.8 Hz), 4.90 (t, 1H, J = 4.2Hz), 4.07 (t, 2H, J = 4.0 Hz), 3.77-3.73 (m, 2H).

Synthesis of Compound [11] Compound [10] (4.00 g, 15.4 mmol) was added in dichloromethane (80 g), and the mixture was cooled under ice cooling. Triethylamine (2.34 g), tosyl chloride (3.09 g) and 4-dimethylaminopyridine (0.06 g) were added thereto, and the mixture was stirred at room temperature for 21 hours. Pure water (40 g) was added, and liquid separation was carried out to recover a dichloromethane layer, and 1N hydrochloric acid (40 g), pure water (40 g) and saturated aqueous sodium chloride solution (20 g) were separated and washed in that order, and dried over anhydrous magnesium sulfate. Then, the mixture was filtered and the filtrate was concentrated to obtain compound [11] (yield: 6.10 g, yield: 96%, orange solid).
1H-NMR (400MHz, DMSO-d6, δppm): 8.27 (d, 2H, J = 7.2Hz), 7.92 (d, 2H, J = 7.2Hz), 7.81 (d, 2H, J = 6.8Hz), 7.74 (d, 2H, J = 7.2 Hz), 7.48 (d, 2H, J = 6.8 Hz), 7.00 (d, 2H, J = 7.2 Hz), 4.39-4.36 (m, 2H), 4.26-4.23 (m, 2H), 2.09 (s, 3H).

Synthesis of Compound [12] Compound [4] (3.64 g, 14.0 mmol), compound [11] (6.10 g) and potassium carbonate (2.91 g) were added to dimethylformamide (36 g), and the mixture was heated at 80 ° C. Stir for 21 hours. After cooling to room temperature, pure water (72 g) was added to precipitate crystals. After filtration, the filtered material was washed with methanol (36 g) as a slurry, filtered, and the filtered material was dried to obtain compound [12] (yield: 5.80 g, yield: 83%, pale yellow crystals).
1H-NMR (400MHz, DMSO-d6, δppm): 9.44 (s, 1H), 8.27 (d, 2H, J = 7.2Hz), 8.01 (s, 1H), 7.94 (d, 2H, J = 7.2Hz) , 7.80-7.77 (m, 2H), 7.71 (d, 2H, J = 7.2 Hz), 7.47 (dd, 1H, J = 7.2 Hz, 1.6 Hz), 7.31 (d, 1H, J = 1.6 Hz), 7.19 -7.15 (m, 3H), 4.46-4.44 (m, 4H), 1.50 (s, 9H).

Synthesis of Compound [13] Compound [12] (5.80 g, 11.6 mmol) was added to chloroform (87 g), and the mixture was cooled with water. Trifluoroacetic acid (6.61 g) was added thereto, and the mixture was stirred at 50 ° C for 22 hours. After cooling to room temperature, triethylamine (5.86 g) and pure water (87 g) were added to precipitate crystals. The liquid containing the obtained crystals was filtered, and the residue was washed with a slurry of methanol (60 g), then filtered, and the residue was dried to obtain a crude product (4.3 g). Dimethylformamide (43 g) was added to the crude product, and the mixture was heated with stirring at 80 ° C., methanol (43 g) was added, the mixture was cooled, filtered, and the residue was dried to obtain compound [13] (yield. : 4.13 g, yield: 89%, orange crystal).
1H-NMR (400MHz, DMSO-d6, δppm): 8.27 (d, 2H, J = 6.8Hz), 7.94 (d, 2H, J = 6.8Hz), 7.78 (d, 2H, J = 6.8Hz), 7.52 (d, 1H, J = 6.8 Hz), 7.46 (d, 1H, J = 6.8 Hz), 7.47-7.45 (m, 3H), 7.03 (d, 1H, J = 6.8 Hz), 6.92 (d, 1H, J = 6.8 Hz), 6.82 (s, 1H), 5.22 (br, 2H), 4.46-4.42 (m, 2H), 4.40-4.37 (m, 2H).

Synthesis of Compound [DA-5] Compound [13] (4.13 g, 10.3 mmol) and 5% palladium carbon (0.41 g) were added to dimethylformamide (41 g), and the mixture was stirred at room temperature for 25 hours under a hydrogen atmosphere. did. After purging with nitrogen, dimethylformamide (82 g) was added and the mixture was heated to 120 ° C., the catalyst was filtered off by hot filtration, and the filtrate was concentrated to obtain a crude product (3.84 g). Dimethylformamide (19 g) was added to the crude product and the mixture was heated and dissolved at 100 ° C., then methanol (31 g) was added little by little and cooled to precipitate crystals. The liquid containing the obtained crystals was filtered, and the residue was dried to obtain compound [DA-5] (yield: 3.33 g, yield: 87%, brown crystal).
1H-NMR (400MHz, DMSO-d6, δppm): 7.51 (d, 1H, J = 6.8 Hz), 7.47-7.44 (m, 3H), 7.29 (d, 2H, J = 6.8 Hz), 7.16 (d, 1H, J = 1.6 Hz), 7.03-6.99 (m, 3H), 6.91 (dd, 1H, J = 6.8 Hz, 1.6 Hz), 6.80 (d, 1H, J = 1.6 Hz), 6.62 (d, 2H, J = 6.8 Hz), 5.11 (br, 4H), 4.35 (br, 4H).

4. Synthesis Example of Compound [DA-14] Compound [DA-14] was prepared in the same manner as compound [DA-3] except that 1,2-ethylenediol was changed to 1,3-propanediol. ] Was obtained.

5. Synthesis Example of Compound [DA-15] Compound [DA-15] was prepared in the same manner as compound [DA-4] except that ethylene glycol ditosylate was changed to 1,3-propanediol ditosylate. -15] was obtained.

[viscosity]
Using an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.), the sample amount was 1.1 mL, the cone rotor TE-1 (1 ° 34 ', R24), and the temperature was 25 ° C.
[Molecular weight]
The number average molecular weight (Mn) and the weight average molecular weight (Mw) were calculated as GPC (normal temperature gel permeation chromatography) equipment and converted into polyethylene glycol and polyethylene oxide.
GPC device: Shodex (GPC-101), column: Shodex (KD803, KD805 in series), column temperature: 50 ° C, eluent: N, N-dimethylformamide (lithium bromide-water as an additive) 30 mmol / L of hydrate (LiBr.H ₂ O), 30 mmol / L of phosphoric acid / anhydrous crystal (o-phosphoric acid), 10 ml / L of tetrahydrofuran (THF), flow rate: 1.0 ml / min Calibration curve preparation Standard sample for use: TSK standard polyethylene oxide manufactured by Tosoh Corporation (weight average molecular weight (Mw) about 900,000, 150,000, 100,000, 30,000), and polyethylene glycol manufactured by Polymer Laboratory (peak top molecular weight (Mp ) About 12,000, 4,000, 1,000). In order to avoid overlapping of peaks, the measurement was performed using a sample mixed with four kinds of 900,000, 100,000, 12,000 and 1,000 and three kinds of 150,000, 30,000 and 4,000. Two of the mixed samples were measured separately.

<Measurement of imidization ratio>
20 mg of polyimide powder was put into an NMR sample tube (NMR sampling tube standard, φ5 (Kusano Scientific Co., Ltd.)), and deuterated dimethyl sulfoxide (DMSO-d6, 0.05% TMS (tetramethylsilane) mixed product) (0. (53 ml) was added and ultrasonic waves were applied to completely dissolve. This solution was measured for proton NMR at 500 MHz with an NMR measuring device (JNW-ECA500, manufactured by JEOL Datum). The imidization ratio is determined by using a proton derived from a structure that does not change before and after imidization as a reference proton, and the integrated value of the peak of this proton and the proton peak derived from the NH group of amic acid that appears near 9.5 ppm to 10.0 ppm. It was calculated by the following formula using the integrated value.
Imidization rate (%) = (1-α · x / y) × 100
In the above formula, x is the proton peak integrated value derived from the NH group of amic acid, y is the peak integrated value of the reference proton, and α is the NH of the amic acid in the case of polyamic acid (imidization ratio is 0%). It is the ratio of the number of reference protons to one base proton.

[Configuration of FFS driving liquid crystal cell]
In a liquid crystal cell for fringe field switching (FFS) mode, a FOP (Finger on Plate) electrode layer including a surface-shaped common electrode-insulating layer-comb-shaped pixel electrode is formed on the surface. One glass substrate and a second glass substrate having a columnar spacer having a height of 4 μm on the front surface and having an ITO film for preventing electrification formed on the back surface were set as a set. The pixel electrode has a comb-tooth shape in which a plurality of electrode elements each having a width of 3 μm and whose central portion is bent at an internal angle of 160 ° are arranged in parallel at intervals of 6 μm, and one pixel is It has a first region and a second region with a line connecting the bent portions of the plurality of electrode elements as a boundary.
The liquid crystal alignment film formed on the first glass substrate is subjected to an alignment treatment so that the direction that evenly divides the interior angle of the bent portion of the pixel and the alignment direction of the liquid crystal are orthogonal to each other, and the liquid crystal alignment film that is formed on the second glass substrate is aligned. The film is subjected to alignment treatment so that the alignment direction of the liquid crystal on the first substrate and the alignment direction of the liquid crystal on the second substrate coincide with each other when the liquid crystal cell is manufactured.

[Production of liquid crystal cell]
A liquid crystal aligning agent filtered with a filter having a pore size of 1.0 μm was applied to the surface of each of the above-mentioned glass substrates by spin coating, and dried on a hot plate at 80 ° C. for 2 minutes. After that, a predetermined amount of linearly polarized UV light having a wavelength of 254 nm with an extinction ratio of 26: 1 is applied to the surface of the coating film through a polarizing plate, and then baked in a hot air circulating oven at 230 ° C. for 30 minutes to form a liquid crystal film having a thickness of 100 nm. A substrate with an alignment film was obtained.
Next, a sealant was printed on one of the pair of glass substrates with a liquid crystal alignment film, the other substrate was attached so that the liquid crystal alignment film surfaces faced each other, and the sealant was cured to prepare an empty cell. Liquid crystal MLC-3019 (manufactured by Merck & Co., Inc.) was injected into this empty cell by a reduced pressure injection method, and the injection port was sealed to obtain an FFS driven liquid crystal cell. After that, the obtained liquid crystal cell was heated at 120 ° C. for 1 hour and left overnight, and then the afterimage characteristics were evaluated.

[Evaluation of afterimage characteristics by long-term AC drive]
An AC voltage of ± 5 V at a frequency of 60 Hz was applied to the FFS-driven liquid crystal cell produced above under a constant temperature environment of 60 ° C. for 120 hours. Then, the pixel electrode and the counter electrode of the liquid crystal cell were short-circuited and left at room temperature for one day.
With respect to the liquid crystal cell that has been subjected to the above processing, 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 when no voltage is applied was calculated as an angle.
Specifically, a liquid crystal cell is installed between two polarizing plates arranged so that their polarization axes are orthogonal to each other, a backlight is turned on, and the liquid crystal cell is arranged so that the transmitted light intensity in the first region of the pixel is minimized. The arrangement angle was adjusted, 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 the rotation angle, the better the afterimage characteristic due to the long-term AC drive. When the value of the angle Δ of the liquid crystal cell was 0.1 ° or less, it was evaluated as “good”.

[Synthesis example of polyamic acid and polyimide]
Hereinafter, synthesis examples of polyamic acid and polyimide will be shown. In these nomenclature, A is the component (A), B is the component (B), C is neither the component (A) nor the component (B), and PI is polyimide. It means that.

<Synthesis example 1>
In a 200 mL four-necked flask equipped with a stirrer and a nitrogen introduction tube, 1.95 g (8.00 mmol) of DA-1, 1.30 g (12.0 mmol) of DA-2 and 3.53 g of DA-3 ( 12.0 mmol) and DA-7 (1.90 g, 8.00 mmol) were taken, NMP (99.73 g) was added, and the mixture was dissolved by stirring while feeding nitrogen. While stirring this diamine solution, 7.35 g (32.8 mmol) of CA-1 and 1.50 g (6.0 mmol) of CA-2 were added, and the mixture was stirred at 40 ° C. for 24 hours to obtain a polyamic acid solution (A- 1) (viscosity: 460 mPa · s) was obtained. The molecular weight of the polyamic acid was Mn = 9100 and Mw = 28000.

<Synthesis Examples 2 to 11, 16 to 19>
A polyamic acid solution (A-2) to (A-11) shown in Table 1 below was prepared in the same manner as in Synthesis Example 1 except that the diamine component and the tetracarboxylic acid component were changed to those shown in Table 1 below. ) And (B-1) to (B-4) were obtained. The viscosity and molecular weight of the obtained polyamic acid are shown in Table 1 below.

<Synthesis example 12>
100 g of the obtained polyamic acid solution (A-1) was placed in a 3 L four-necked flask equipped with a stirrer and equipped with a nitrogen introducing tube, 50 g of NMP was added, and the mixture was stirred for 30 minutes. 16.30 g of acetic anhydride and 5.05 g of pyridine were added to the obtained polyamic acid solution, and the mixture was heated at 50 ° C. for 3 hours for chemical imidization. The obtained reaction solution is poured into 600 ml of methanol while stirring, the deposited precipitate is collected by filtration, and the same operation is performed twice to wash the resin powder, and then dried at 60 ° C. for 12 hours. Then, a polyimide resin powder was obtained. The imidation ratio of this polyimide resin powder was 71%, Mn = 11,000 and Mw = 38,000. 3.60 g of the obtained polyimide resin powder was placed in a 100 ml Erlenmeyer flask, 26.4 g of NMP was added so that the solid content concentration was 12%, and the mixture was stirred and stirred at 70 ° C. for 24 hours to dissolve the polyimide solution (A-1- PI) was obtained (see Table 2 below).

<Synthesis Examples 13 to 15, 20 to 21>
The same procedure as in Synthesis Example 8 was performed except that the polyamic acid in Table 2 below was used instead of the polyamic acid solution (A-1) and the imidization conditions were changed to those in Table 2 below. Thus, a polyimide solution (A-2-PI) to a polyimide solution (A-11-PI) were obtained. The molecular weight of the obtained polyimide is shown in Table 2 below.

[Production of liquid crystal aligning agent]
<Example 1>
50 ml of 12 g by mass of the polyamic acid solution (A-1-PI) obtained in Synthesis Example 12 and 4.8 g of the 15 mass% of the polyamic acid solution (B-1) obtained in Synthesis Example 10 were used. The mixture was placed in an Erlenmeyer flask, NMP 1.20 g, GBL 6.00 g and BCS 4.00 g were added and mixed at 25 ° C. for 8 hours to obtain a liquid crystal aligning agent (1) (see Table 3 below). No abnormalities such as turbidity and precipitation were observed in this liquid crystal aligning agent, and it was confirmed that the liquid crystal aligning agent was a uniform solution.

<Examples 2 to 16, Comparative Examples 1 and 2>
By following the same procedure as in Example 1 except that the polyamic acid solution and the polyimide solution shown in Table 3 below were used instead of the polyimide acid solution (A-1-PI) and the polyamic acid solution (B-1). Thus, liquid crystal aligning agents (2) to (18) were obtained. No abnormalities such as turbidity and precipitation were observed in these liquid crystal aligning agents, and it was confirmed that they were uniform solutions.

[Result of afterimage evaluation by long-term AC drive (when firing is performed before UV irradiation)]
<Example 21>
After filtering the liquid crystal aligning agent (1) of Example 1 with a filter having a pore size of 1.0 μm, a glass substrate having the prepared electrode-attached substrate and a columnar spacer having a height of 4 μm on which an ITO film is formed on the back surface Was applied by spin coating. After drying for 2 minutes on a hot plate at 80 ° C., baking was performed for 30 minutes in a hot air circulation type oven at 230 ° C. to form a coating film having a film thickness of 100 nm. This coating film surface was irradiated with linearly polarized ultraviolet light having a wavelength of 254 nm having an extinction ratio of 26: 1 through a polarizing plate and then baked in a hot air circulation oven at 230 ° C. for 30 minutes to obtain a substrate with a liquid crystal alignment film. . A set of the above-mentioned two substrates is printed, a sealant is printed on the substrates, and the other substrate is bonded so that the liquid crystal alignment film surfaces face each other and the alignment direction becomes 0 °, and then a seal is formed. The agent was cured to prepare an empty cell. Liquid crystal MLC-3019 (manufactured by Merck & Co., Inc.) was injected into this empty cell by a reduced pressure injection method, and the injection port was sealed to obtain an FFS driven liquid crystal cell. After that, the obtained liquid crystal cell was heated at 120 ° C. for 1 hour and left overnight, and afterimage evaluation by long-term AC driving was performed. The value of the angle Δ of the liquid crystal cell after long-term AC driving is 0.09 ° when the irradiation amount of the ultraviolet rays is 200 mJ / cm ² , and 0.1 ° when the irradiation amount of 300 mJ / cm ² is 300 mJ / cm ² . Since all are 0.1 ° or less, good liquid crystal aligning property was obtained by the liquid crystal aligning agent (1) (see Table 4 below).

<Examples 22 to 32, Comparative Examples 21 and 22>
Example 21 except that the liquid crystal aligning agent shown in Table 4 below was used instead of the liquid crystal aligning agent (1) of Example 1 and the ultraviolet irradiation dose was changed to the ultraviolet irradiation dose shown in Table 4 below. An FFS-driving liquid crystal cell was produced by the same method as above, and afterimage evaluation by long-term AC driving was performed. Table 4 shows the value of the angle Δ of the liquid crystal cell after the long-term AC driving.

[Evaluation result of afterimage by long-term AC drive (when firing is not performed before UV irradiation)]
<Example 41>
After filtering with a filter having a pore size of 1.0 μm using the liquid crystal aligning agent (1) of Example 1, the prepared substrate with an electrode and a columnar spacer having a height of 4 μm on which an ITO film is formed on the back surface are provided. It was applied to a glass substrate by spin coating. After drying for 2 minutes on a hot plate at 80 ° C, this coating film surface was irradiated with linearly polarized ultraviolet light having a wavelength of 254 nm with an extinction ratio of 26: 1 via a polarizing plate, and then in a hot air circulation oven at 230 ° C. After baking for 30 minutes, a substrate with a liquid crystal alignment film having a film thickness of 100 nm was obtained. A set of the above-mentioned two substrates is printed, a sealant is printed on the substrates, and the other substrate is bonded so that the liquid crystal alignment film surfaces face each other and the alignment direction is 0 °, and then a seal is formed. The agent was cured to prepare an empty cell. Liquid crystal MLC-3019 (manufactured by Merck & Co., Inc.) was injected into this empty cell by a reduced pressure injection method, and the injection port was sealed to obtain an FFS driven liquid crystal cell. After that, the obtained liquid crystal cell was heated at 120 ° C. for 1 hour and left overnight, and afterimage evaluation by long-term AC driving was performed. The value of the angle Δ of the liquid crystal cell after long-term AC driving is 0.07 ° when the dose of the ultraviolet rays is 200 mJ / cm ² , and 0.07 ° when the dose is 300 mJ / cm ² . Since all are 0.1 ° or less, good liquid crystal aligning property was obtained by the liquid crystal aligning agent (1) (see Table 5 below).

<Examples 42 to 49, Comparative Examples 41 and 42>
Example 41, except that the liquid crystal aligning agent shown in Table 5 below was used in place of the liquid crystal aligning agent (1) of Example 1 and the ultraviolet irradiation dose was changed to the ultraviolet irradiation dose shown in Table 5 below. An FFS-driving liquid crystal cell was produced by the same method as above, and afterimage evaluation by long-term AC driving was performed. Table 5 shows the values of the angle Δ of the liquid crystal cell after long-term AC driving.

As shown in Tables 4 and 5, in Examples 1 to 12, the angle Δ (deg.) Is also an angle Δ of 0.1 ° or less, which is a good afterimage characteristic. Therefore, it is possible to improve the display quality of the liquid crystal display device. Excel.

INDUSTRIAL APPLICABILITY The liquid crystal aligning agent of the present invention is used in a wide range of fields such as large-sized liquid crystal display devices that require high definition and low cost, and mobile liquid crystal display devices such as smartphones and mobile phones.
The entire contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2018-196761 filed on Oct. 18, 2018 are cited herein as disclosure of the specification of the present invention. , Take in.

Claims

From the group consisting of a polyamic acid obtained by reacting a diamine component containing a diamine having a structure represented by the following formula [1] with a tetracarboxylic dianhydride component, and a polyimide obtained by imidizing the polyamic acid. A liquid crystal aligning agent comprising at least one polymer selected.

(In the formula [1], A 1 and A 2 are each independently a monocyclic group which may have a substituent or a condensed ring group, and A 1 and A 2 are simultaneously a monocyclic group. X 1 and X 2 are each independently a single bond, an oxygen atom or a sulfur atom, Q is an alkylene group having 1 or 2 carbon atoms, and m and n are each independently. And is an integer of 1 to 3.)
The liquid crystal aligning agent according to claim 1, wherein in the formula [1], Q is an alkylene group having 2 carbon atoms.
In the formula [1], the liquid crystal aligning agent according to claim 1 or 2, wherein X 1 and X 2 are oxygen atoms.
The liquid crystal aligning agent according to any one of claims 1 to 3, wherein the diamine having a structure represented by the formula [1] is any one of the following diamines.
The liquid crystal aligning agent according to any one of claims 1 to 4, wherein the content of the diamine having the structure represented by the formula [1] in the diamine component is 5 to 95 mol%.
The liquid crystal aligning agent according to any one of claims 1 to 5, wherein the tetracarboxylic dianhydride component is a tetracarboxylic dianhydride represented by the following formula [7] or a derivative thereof.

(In the formula [7], Z 1 is a tetravalent organic group.)
7. The liquid crystal aligning agent according to claim 6, wherein Z 1 has any of the structures represented by any of the following formulas (X1-1) to (X1-19).

(In formulas (X1-1) and (X1-2), R 3 to R 12 are each independently 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, or a phenyl group, provided that at least one of R 3 to R 6 is a group other than a hydrogen atom. is there.)
The liquid crystal aligning agent according to claim 7, wherein Z 1 has a structure represented by formula (X1-1).
A liquid crystal alignment film obtained from the liquid crystal alignment agent according to any one of claims 1 to 8.
A liquid crystal display device comprising the liquid crystal alignment film according to claim 9.
A diamine having a structure represented by the following formula [1].

(In the formula [1], A 1 and A 2 are each independently a monocyclic group which may have a substituent or a condensed ring group, and A 1 and A 2 are simultaneously a monocyclic group. X 1 and X 2 are each independently a single bond, an oxygen atom or a sulfur atom, Q is an alkylene group having 1 or 2 carbon atoms, and m and n are each independently. And is an integer of 1 to 3.)
The diamine according to claim 11, wherein the diamine having the structure represented by the formula [1] is any of the diamines represented below.