JP7400728B2 - Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element using the same - Google Patents

Description

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

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

Diamine compounds, which are raw materials for such polyamic acids and polyimides, are important because they affect the properties of the liquid crystal alignment film obtained from them, and by extension, the properties of liquid crystal display elements, and various diamine compounds have been used in the past. Proposed.

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

Japanese Patent Application Publication No. 2005-157346

However, in recent years, the performance of liquid crystal display elements has increased, the area has become larger, and the power consumption of display devices has improved, and in addition, liquid crystal display elements have come to be used in a variety of environments. The characteristics that can be achieved are also becoming more severe. In particular, as the use of liquid crystal display elements progresses, the problem of difficulty in ensuring good liquid crystal alignment and the problem of a small sensitivity margin when producing a liquid crystal alignment film become more prominent. Note that the sensitivity margin here refers to a sensitivity region in which good liquid crystal alignment characteristics can be obtained when irradiated with polarized ultraviolet light.

If good liquid crystal alignment cannot be ensured, light leakage and alignment defects are likely to occur. Furthermore, if the sensitivity margin is small, it causes display unevenness during long-term driving and in-plane variation in the alignment direction of the liquid crystal due to uneven illuminance from an ultraviolet irradiation device, which causes light leakage and unevenness when displaying black. For this reason, although there is a strong demand for good liquid crystal alignment and improved sensitivity margin, conventionally proposed techniques cannot sufficiently satisfy these demands.

The present invention was made in view of the above circumstances, and an object of the present invention is to provide a liquid crystal aligning agent that can obtain a liquid crystal alignment film having good liquid crystal alignment properties and has an increased sensitivity margin. .

（式［１］中、Ａ_１及びＡ_２は、それぞれ独立して、置換基を有していてもよい単環基又は縮合環基であり、Ａ_１及びＡ_２は、同時に単環基であることはない。Ｘ_１ は、酸素原子又は硫黄原子であり、Ｘ_２は、単結合、酸素原子又は硫黄原子である。Ｑは、炭素数１又は２のアルキレン基である。ｍ及びｎは、それぞれ独立して、１～３の整数である。） The present inventors conducted intensive studies to solve the above problems, and as a result, discovered that a liquid crystal aligning agent containing a polymer obtained from a novel diamine satisfies the above problems.
The present invention is based on this knowledge and has the following gist.
From the group consisting of a polyamic acid obtained by the reaction of a diamine component containing a diamine having the structure represented by the following formula [1] and a tetracarboxylic dianhydride component, and a polyimide obtained by imidizing the polyamic acid. A liquid crystal aligning agent characterized by containing at least one selected polymer.

(In formula [1], A ₁ and A ₂ are each independently a monocyclic group or a fused ring group which may have a substituent, and A ₁ and A ₂ are simultaneously a monocyclic group. There is no _{such thing} . , each independently is an integer from 1 to 3.)

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

上記式［１］中、Ａ_１及びＡ_２は、それぞれ独立して、置換基を有していてもよい単環基又は縮合環基であり、Ａ_１及びＡ_２は、同時に単環基であることはない。Ｘ_１ は、酸素原子又は硫黄原子であり、Ｘ_２は、単結合、酸素原子又は硫黄原子である。Ｑは、炭素数１又は２のアルキレン基である。ｍ及びｎは、それぞれ独立して、１～３の整数である。
<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 or a fused ring group which may have a substituent, and A ₁ and A ₂ are simultaneously a monocyclic group. It never happens. X ₁ is an oxygen atom or a sulfur atom, and X ₂ is 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.

A monocyclic group refers to an atomic group remaining after two hydrogen atoms are removed from a monocyclic ring. 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. In addition, when a monocyclic group is benzene, a monocyclic group is a phenylene group.

A fused ring group refers to an atomic group remaining after two hydrogen atoms are removed from a fused ring. Examples of the fused ring include fused 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 fused polycyclic heterocycles such as phthalazine, quinazoline, and quinoxaline. The fused ring is preferably naphthylene, anthracene, pyrene, indole, carbazole, coumarin, benzo-pyrone, quinoline, or isoquinoline.

The monocyclic group and the fused ring group may further have a substituent. Examples of substituents that the monocyclic group and the fused ring group may have include alkyl having 1 to 4 carbon atoms, alkoxy having 1 to 4 carbon atoms, and a halogen atom.

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

Preferred specific examples of the specific diamine include, but are not limited to, the following.

<Tetracarboxylic 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 preferable to use it as a part.

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

In the above 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 orientation, the structure of At least one type selected from the structures represented by -1) to (X1-1-5) is more preferred, and the following formula (X1-1-1) is particularly preferred. Two or more types of tetracarboxylic dianhydride or its derivatives represented by formula [7] may be used in combination.

The usage ratio of the tetracarboxylic dianhydride or its derivative represented by the above formula [7] is preferably 50 mol% or more with respect to 1 mol of the tetracarboxylic dianhydride component used in the polymer of the present invention, More preferably 70 mol% or more, and even more preferably 80 mol% or more.
Furthermore, if 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, bright spots due to decomposition products may be suppressed. It is preferable from the viewpoint of liquid crystal orientation.

The tetracarboxylic dianhydride component used in the polymerization of the polymer of the present invention may contain a tetracarboxylic dianhydride other than the above formula [7] or a derivative thereof.
One or more tetracarboxylic dianhydrides or derivatives thereof other than the above formula [7] may be used, taking into consideration the properties such as liquid crystal orientation, voltage holding characteristics, and accumulated charge of the liquid crystal alignment film to be formed. 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 reacting a diamine component containing a specific diamine with a tetracarboxylic dianhydride component.
In the diamine component for obtaining a polyamic acid by reaction with the above-mentioned tetracarboxylic dianhydride component, there is no limit to the content ratio of the specific diamine. The content of the specific diamine in the diamine component may be 100%. However, various diamines can be used in combination because they satisfy the various properties required for liquid crystal alignment films, such as increasing the pretilt angle of liquid crystals and increasing the vertical alignment of liquid crystals. . The content of the specific diamine in the diamine component used in the polymerization is preferably 1 to 50 mol%, particularly preferably 5 to 30 mol%.

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

Examples of alicyclic diamines include 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, 4,4'-diaminodicyclohexylmethane, 4,4'-diamino-3,3'-dimethyldicyclohexylamine, and isophorone diamine. 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'-diaminodiphenylsulfide, 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, 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-aminophenoxy)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-diaminanthraquinone, 1,3-diaminopyrene , 1,6-diaminopyrene, 1,8-diaminopyrene, 2,7-diaminofluorene, 1,3-bis(4-aminophenyl)tetramethyldisiloxane, 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-amino phenoxy)pentane, 1,6-bis(4-aminophenoxy)hexane, 1,7-bis(4-aminophenoxy)heptane, 1,8-bis(4-aminophenoxy)octane, 1,9-bis(4-aminophenoxy)heptane, -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)butane-1,4-dioate, (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-aminophenoxy)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-bis[4-(4-aminophenoxy)phenoxy]decane, and the like.

Examples of aromatic-aliphatic diamines include 3-aminobenzylamine, 4-aminobenzylamine, 3-amino-N-methylbenzylamine, 4-amino-N-methylbenzylamine, 3-aminophenethylamine, 4-aminobenzylamine, 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-( Examples include 6-aminonaphthyl)methylamine, 3-(6-aminonaphthyl)methylamine, 2-(6-aminonaphthyl)ethylamine, and 3-(6-aminonaphthyl)ethylamine.

Examples of heterocyclic diamines include 2,6-diaminopyridine, 2,4-diaminopyridine, 2,4-diamino-1,3,5-triazine, 2,7-diaminodibenzofuran, 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 aliphatic diamines 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.

（Ｒ_６は、炭素数１～２２を有する、アルキル基又はフッ素含有アルキル基である。）A diamine having an alkyl group, a fluorine-containing alkyl group, an aromatic ring, an aliphatic ring, a heterocycle, or a macrocyclic substituent thereof in the side chain may be used in combination. 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は、－ＣＯＯ－、－ＯＣＯ－、－ＣＯＮＨ－、－ＮＨＣＯ－、－ＣＨ_２－、－Ｏ－、－ＣＯ－、又はＮＨ－であり、Ｒ_６は炭素数１～２２を有する、アルキル基若しくはフッ素含有アルキル基である。）

(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は、－Ｏ－、－ＯＣＨ_２－、－ＣＨ_２Ｏ－、－ＣＯＯＣＨ_２－、又はＣＨ_２ＯＣＯ－であり、Ｒ_７は炭素数１～２２を有する、アルキル基、アルコキシ基、フッ素含有アルキル基若しくはフッ素含有アルコキシ基である。）

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

（Ｓ_７は、－ＣＯＯ－、－ＯＣＯ－、－ＣＯＮＨ－、－ＮＨＣＯ－、－ＣＯＯＣＨ_２－、－ＣＨ_２ＯＣＯ－、－ＣＨ_２Ｏ－、－ＯＣＨ_２－、又はＣＨ_２－であり、Ｒ_８は炭素数１～２２を有する、アルキル基、アルコキシ基、フッ素含有アルキル基若しくはフッ素含有アルコキシ基である。）

(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, alkoxy group, fluorine-containing alkyl group, or fluorine-containing alkoxy group having 1 to 22 carbon atoms.)

（Ｓ_８は、－ＣＯＯ－、－ＯＣＯ－、－ＣＯＮＨ－、－ＮＨＣＯ－、－ＣＯＯＣＨ_２－、－ＣＨ_２ＯＣＯ－、－ＣＨ_２Ｏ－、－ＯＣＨ_２－、－ＣＨ_２－、－Ｏ－、又はＮＨ－であり、Ｒ_９はフッ素基、シアノ基、トリフルオロメタン基、ニトロ基、アゾ基、ホルミル基、アセチル基、アセトキシ基、又は水酸基である。）

(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.)

（Ｒ₁₀は炭素数３～１２のアルキル基であり、１，４－シクロへキシレンのシス－トランス異性は、それぞれトランス体である。）

(R ₁₀ is an alkyl group having 3 to 12 carbon atoms, and each cis-trans isomer of 1,4-cyclohexylene is a trans isomer.)

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

（ｍは０～３の整数であり、式［ＤＡ－１３８］中、ｎは１～５の整数である）。

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

By containing diamines such as formula [DA-131] and formula [DA-132], voltage holding characteristics when used as a liquid crystal alignment film can be improved, and formulas [DA-133] to [DA-138] ] Diamines are effective in reducing accumulated charge.

（ｍは、１～１０の整数である。）Furthermore, diaminosiloxane represented by the following formula [DA-139] can also be mentioned as other diamines.

(m is an integer from 1 to 10.)

（式（８）中、Ｙ_２は芳香族基に結合する窒素原子又は含窒素芳香族複素環を有する２価の有機基である。）Furthermore, a diamine represented by the following formula (8) can also be mentioned as other diamines.

(In formula (8), _Y2 is a nitrogen atom bonded to an aromatic group or a divalent organic group having a nitrogen-containing aromatic heterocycle.)

Examples of Y ₂ in 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 the properties such as liquid crystal orientation, voltage holding characteristics, and accumulated charge when used as a liquid crystal alignment film.

<Production of polyamic acid>
A known method can be used to obtain the polyamic acid of the present invention by reacting the tetracarboxylic dianhydride component and the diamine component. For example, there is a method in which a tetracarboxylic dianhydride component and a diamine component are reacted in an organic solvent. In this case, the reaction between the tetracarboxylic dianhydride component and the diamine is advantageous in that it proceeds relatively easily in an organic solvent and no by-products are generated.

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 produced polyamic acid. Specific examples are listed 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, methoxymethylpentanol, 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 mono Propyl 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, acetic acid n -Butyl, acetate propylene glycol monoethyl ether, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methylethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropion Acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, diglyme, 4-hydroxy-4-methyl-2-pentanone, 3-methoxy-N,N-dimethylpropanamide, 3-ethoxy-N,N- Examples include dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide, and the like. These may be used alone or in combination. Furthermore, even a solvent that does not dissolve polyamic acid may be mixed with the above-mentioned solvent to the extent that the produced polyamic acid does not precipitate.

Further, since moisture in the organic solvent inhibits the polymerization reaction and further causes hydrolysis of the produced polyamic acid, it is preferable that the organic solvent be dehydrated and dried as much as possible.
When reacting a tetracarboxylic dianhydride component and a diamine component in an organic solvent, a solution in which the diamine component is dispersed or dissolved in an organic solvent is stirred, and the tetracarboxylic dianhydride component is reacted as it is or in an organic solvent. A method in which the diamine component is added by dispersing or dissolving it in a solvent, a method in which the diamine component is added to a solution in which the tetracarboxylic dianhydride component is dispersed or dissolved in an organic solvent, and a method in which the diamine component is added by dispersing or dissolving the tetracarboxylic dianhydride component in an organic solvent. Examples include a method of adding them alternately, and any of these methods may be used. In addition, when the tetracarboxylic dianhydride component or the diamine component consists of multiple types of compounds, they may be reacted in a pre-mixed state, they may be reacted individually in sequence, and furthermore, low molecular weight compounds may be reacted individually. It is also possible to make a high molecular weight product by subjecting it to a mixed reaction.

The temperature at which the tetracarboxylic dianhydride component and the diamine component are reacted can be any temperature in the range of -20 to 150°C, but is preferably in the range of -5 to 100°C. In addition, the reaction can be carried out at any concentration, but if the concentration is too low, it will be difficult to obtain a high molecular weight polymer, and if the concentration is too high, the viscosity of the reaction solution will become too high, making it difficult to stir uniformly. 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 initial stage of the reaction can be carried out at a high concentration, and then an organic solvent can be added.
In the polymerization reaction of 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, more preferably 0.9 to 1. 1 is more preferred. Similar to normal polycondensation reactions, the closer this molar ratio is to 1.0, the larger the molecular weight of the polyamic acid produced becomes.

<Polyimide>
The polyimide of the present invention is a polyimide obtained by dehydrating and ring-closing the polyamic acid described above, 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 depending on the use and purpose.
Examples of methods for imidizing polyamic acid include a thermal imidization method in which a polyamic acid solution is directly heated, and a catalytic imidization method in which a catalyst is added to a polyamic acid solution.
When thermally imidizing polyamic acid in a solution, the temperature is 100 to 400°C, preferably 120 to 250°C, and the process is preferably carried out while removing water produced by the imidization reaction from the system.

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 at -20 to 250°C, preferably 0 to 180°C. The amount of the basic catalyst is 0.5 to 30 times the mole of the amic acid group, preferably 2 to 20 times the mole, and the amount of the acid anhydride is 1 to 50 times the mole of the amic acid group, preferably 3 to 20 times the mole of the amic acid group. 30 moles. Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine, etc. Among them, pyridine is preferred because it has basicity suitable for advancing the reaction. Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, pyromellitic anhydride, etc. Among them, acetic anhydride is preferably used because it facilitates purification after the reaction is completed. The imidization rate by catalytic imidization can be controlled by adjusting the amount of catalyst, reaction temperature, reaction time, etc.

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

<Liquid crystal alignment agent>
The liquid crystal alignment agent of the present invention is a coating liquid for forming a liquid crystal alignment 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 includes at least one kind of 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, 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 therein. At this 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 polymers include polyamic acids or polyimides 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 in 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 listed below.
N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 2-pyrrolidone, N-ethylpyrrolidone, N-vinylpyrrolidone, dimethylsulfoxide, tetramethylurea, pyridine, Dimethylsulfone, hexamethylsulfoxide, 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-methyl-2-pentanone, etc. . These may be used alone or in combination.

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

For example, isopropyl alcohol, methoxymethylpentanol, 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 monoacetate. 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, 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, 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, n-hexane, n-pentane, n-octane, diethyl ether, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl acetate, methyl pyruvate, pyruvin Ethyl acid, methyl 3-methoxypropionate, methylethyl 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, Examples include solvents having low surface tension such as lactate methyl ester, lactate ethyl ester, lactate n-propyl ester, lactate n-butyl ester, and lactate isoamyl ester.
These poor solvents may be used alone or in combination. When the above-mentioned solvent is used, it is preferably 5 to 80% by mass, more preferably 20 to 60% by mass of the total solvent contained in the liquid crystal aligning agent.

Examples of compounds that improve film thickness uniformity and surface smoothness include fluorosurfactants, silicone surfactants, and nonionic surfactants.
More specifically, for example, FTOP EF301, EF303, EF352 (manufactured by Tochem Products), Megafac F171, F173, R-30 (manufactured by Dainippon Ink), Florado 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 proportion of these surfactants used is preferably 0.01 to 2 parts by mass, more preferably 0.01 to 1 part by mass, based on 100 parts by mass of the resin component contained in the liquid crystal aligning agent.

Specific examples of compounds that improve the adhesion between the liquid crystal alignment film and the substrate include the following functional silane-containing compounds and epoxy group-containing compounds.
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-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, N-bis(oxyethylene)-3-aminopropyltrimethoxy Silane, 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, neo Pentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol , N,N,N',N',-tetraglycidyl-m-xylene diamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N',-tetraglycidyl -4,4'-diaminodiphenylmethane and the like.

Further, in addition to improving the adhesion between the substrate and the film, it is preferable to include the following phenoplast-based additives for the purpose of preventing deterioration of electrical properties due to backlighting. Specific phenoplast additives are shown below.

When using a compound that improves adhesion to the substrate, the amount used is preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass, per 100 parts by mass of the resin component. be. If the amount used is less than 0.1 part by mass, no effect of improving adhesion can be expected, and if it is more than 30 parts by mass, the alignment of the liquid crystal may deteriorate.
In addition to the above, the liquid crystal aligning agent of the present invention includes dielectrics, conductive substances, and furthermore, for the purpose of changing the electrical properties such as dielectric constant and conductivity of the liquid crystal aligning film. A crosslinkable compound or the like may be added for the purpose of increasing hardness or compactness.

<Liquid crystal alignment film and liquid crystal display element>
The liquid crystal aligning agent of the present invention is coated on a substrate, baked, and then subjected to alignment treatment by rubbing or light irradiation, or can be used as a liquid crystal alignment film without alignment treatment in vertical alignment applications. At this time, the substrate used is not particularly limited as long as it is a highly transparent substrate, and plastic substrates such as glass substrates, acrylic substrates, and polycarbonate substrates can be used. Furthermore, it is preferable to use a substrate on which ITO electrodes and the like for driving the liquid crystal are formed, from the viewpoint of process simplification. 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 light-reflecting material such as aluminum can also be used for the electrodes.
The method of applying the liquid crystal aligning agent is not particularly limited, but industrially, methods such as screen printing, offset printing, flexo printing, and inkjet are generally used. Other coating methods include dip, roll coater, slit coater, spinner, etc., and these may be used depending on the purpose.

After applying the liquid crystal aligning agent onto the substrate, baking is performed at 50 to 300° C., preferably 80 to 250° C., using a heating means such as a hot plate to evaporate the solvent and form a coating film. The thickness of the coating film formed after firing is preferably 5 to 300 nm, and more preferably 5 to 300 nm, because if it is too thick, it will be 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. Preferably it is 10 to 100 nm. When liquid crystals are to be horizontally aligned or tilted, the coating film after firing is treated by rubbing or irradiation with polarized ultraviolet rays.
The method for aligning the liquid crystal aligning film obtained from the liquid crystal aligning agent of the present invention may be a rubbing treatment method, but with the liquid crystal aligning agent of the present invention, the alignment treatment can be performed with an expanded irradiation dose margin as described above. Therefore, the photo-alignment treatment method is suitable. As a preferable example of the photo-alignment treatment method, radiation having a wavelength of 100 to 800 nm, preferably ultraviolet rays or visible light, can be used on the surface of the liquid crystal alignment film. Among these, ultraviolet light having a wavelength of preferably 100 to 400 nm, more preferably 200 to 400 nm.
The amount of light irradiation in the photo-alignment treatment method is preferably 1 to 10,000 mJ/cm ² , more preferably 100 to 5,000 mJ/cm ² , particularly preferably 100 to 2000 mJ/cm ² .
The liquid crystal display element of the present invention is obtained by obtaining a substrate with a liquid crystal alignment film from the liquid crystal aligning agent of the present invention by the method described above, and then producing a liquid crystal cell by a known method to obtain a liquid crystal display element.

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

The present invention will be described in more detail with reference to Examples below, but the present invention is not limited thereto. The abbreviations of the compounds and the measurement methods for each property 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 on ice. Sodium hydride (60%, 29.6 g) was added little by little thereto, and the mixture was stirred for 1 hour under ice-cooling, then benzyl bromide (121 g) was added, and the mixture was stirred at room temperature for 1 hour. Further, while cooling with water, pure water (750 g) was added little by little and stirred to precipitate crystals. The obtained crystal-containing liquid was filtered, the filtered material was slurried washed with methanol (750 g), filtered, and the filtered material 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] Sodium tert-butoxy (82.6 g) and benzophenone imine (126 g) were added to tetrahydrofuran (1000 g), and the mixture was stirred at room temperature for 30 minutes. Compound [1] (207 g, 661 mmol), Pd ₂ (dba) ₃ (3.03 g) and BINAP (6.17 g) were added to this, 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, stirred at room temperature for 15 minutes, and the aqueous layer was separated. Furthermore, ethyl acetate (200 g), hexane (100 g) and 1N hydrochloric acid (500 g) were added to the organic layer, and the mixture was added to the separated aqueous layer. While cooling with water, sodium hydroxide (80 g) was added to make it alkaline. The organic layer was separated, washed with a 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 dissolved by heating at 70°C, then hexane (770 g) was added and cooled. Compound [2] was obtained by filtering and drying the filtered product (yield: 124 g, yield: 74%, light brown crystals).
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, di-tert-butyl dicarbonate (10 g) was further added and the mixture was further stirred at room temperature for 20 hours. Saturated aqueous sodium hydrogen carbonate solution (1000 mL) and dichloromethane (300 g) were added and the mixture was separated. The organic layer was washed with pure water (450 mL) and a saturated aqueous sodium chloride solution (300 mL) in that 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 dissolved by heating at 70°C, then hexane (1000 g) was added and cooled. Compound [3] was obtained by filtering and drying the filtered product (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 = 8.6 Hz), 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] To dimethyl sulfoxide (500 g), 4-chloronitrobenzene (100 g, 635 mmol), ethylene glycol (551 g) and sodium hydroxide (23.1 g) were added and stirred at 100° C. for 19 hours. After cooling to room temperature, ethyl acetate (560 g) and pure water (700 g) were added to separate the layers. 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 layer 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 ( 110g). Ethyl acetate (330 g) was added to the crude product and dissolved by heating at 60° C., then hexane (550 g) was added and cooled. Then, the obtained liquid was filtered and the filtered material was dried to obtain compound [5] (yield: 64.2 g, yield: 55%, pale yellow crystals).
1H-NMR (400MHz, DMSO-d6, δppm): 8.21(d, 2H, J = 9.4 Hz), 7.16(d, 2H, J = 9.4 Hz), 4.97(t, 1H, J = 5.6 Hz), 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 on ice. To this were added triethylamine (52.4 g), tosyl chloride (69.0 g) and 4-dimethylaminopyridine (1.26 g), and the mixture was stirred at room temperature for 19 hours. Add pure water (632 g), separate the layers, collect the dichloromethane layer, wash with 1N hydrochloric acid (300 g), pure water (300 g), and saturated aqueous sodium chloride solution (300 g) in this order, and dry over anhydrous sodium sulfate. Compound [6] was obtained by filtering and concentrating the filtrate (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] Compound [4] (45.0 g, 174 mmol), compound [6] (61.5 g) and potassium carbonate (36.0 g) were added to dimethylformamide (360 g), and the mixture was heated at 80°C. Stirred for 21 hours. After cooling to room temperature, pure water (720 g) was added to precipitate crystals. The obtained crystal-containing liquid was filtered, the filtered material was slurried washed with methanol (360 g), filtered, and the filtered material 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] Compound [7] (73.1 g, 172 mmol) was added to chloroform (1096 g), trifluoroacetic acid (98.1 g) was added while stirring under water cooling, and the mixture was heated at 50°C. Stirred for 19 hours. After cooling the resulting stirred liquid to room temperature, triethylamine (87.0 g) and pure water (1096 g) were added to precipitate crystals. The obtained crystal-containing liquid was filtered, and the filtered material was washed with methanol (365 g) as a slurry, filtered, and the filtered material 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., and then methanol (248 g) was added and cooled to precipitate crystals. The obtained crystal-containing liquid was filtered and the filtered material was dried to obtain compound [8] (yield: 47.3 g, yield: 85%, orange crystals).
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 on carbon (4.6 g) were added to dimethylformamide (371 g), and the mixture was heated at 60°C for 19 hours under a hydrogen atmosphere. Stirred. Since the reaction had not progressed much, the mixture was stirred at 60° C. for 8 hours in an autoclave under a 0.4 MPa hydrogen atmosphere. After purging with nitrogen, the catalyst was filtered off, and the filtrate was concentrated to a content of 80 g. Dimethylformamide (46 g) was added and dissolved by heating at 90° C., then methanol (210 g) was added and cooled to precipitate crystals. Then, the obtained crystal-containing liquid was filtered and the filtered material 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 of Compound [3], was used.

Synthesis of Compound [9] In dimethylformamide (607 g), ethylene glycol ditosylate (60.7 g, 164 mmol), compound [4] (89.3 g) and potassium carbonate (56.7 g) were added, and the mixture was heated at 80°C for 22 hours. Stirred. After cooling the stirred liquid to room temperature, pure water (1200 g) was added to precipitate crystals. Then, the obtained crystal-containing liquid was filtered, and the filtered material was slurried washed with methanol (450 g), filtered, and the filtered material 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., and then methanol (839 g) was added and cooled to precipitate crystals. Then, the obtained crystal-containing liquid was filtered and the filtered material was dried to obtain compound [9] (yield: 71.2 g, yield: 80%, orange crystals).
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 with water. Trifluoroacetic acid (160 g) was added to this, 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 obtained crystal-containing liquid was filtered, and the filtrate was washed as a slurry with methanol (400 g), filtered, and the filtrate 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., and then methanol (225 g) was added and cooled to precipitate crystals. The obtained crystal-containing liquid was filtered and the filtered material 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 [4] Compound [4], which is a synthetic intermediate of Compound [3], was used.

Synthesis of Compound [10] In dimethylformamide (35 g), 4-hydroxy-4'-nitrobiphenyl (5.00 g, 23.2 mmol) and potassium carbonate (8.02 g) were added and 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. Compound [10] was obtained by slurry washing the filtrate with methanol (35 g), filtering, and drying the filtrate (yield: 4.35 g, yield: 72%, yellow crystals).
1H-NMR (400MHz, DMSO-d6, δppm): 8.27(d, 2H, J = 7.2 Hz), 7.92(d, 2H, J = 7.2 Hz), 7.76(d, 2H, J = 6.8 Hz), 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 to dichloromethane (80 g), and the mixture was cooled on ice. Triethylamine (2.34 g), tosyl chloride (3.09 g) and 4-dimethylaminopyridine (0.06 g) were added to this, and the mixture was stirred at room temperature for 21 hours. Add pure water (40 g), separate the layers, collect the dichloromethane layer, wash with 1N hydrochloric acid (40 g), pure water (40 g), and saturated sodium chloride aqueous solution (20 g) in this order, and dry over anhydrous magnesium sulfate. Compound [11] was obtained by filtering and concentrating the filtrate (yield: 6.10 g, yield: 96%, orange solid).
1H-NMR (400MHz, DMSO-d6, δppm): 8.27(d, 2H, J = 7.2 Hz), 7.92(d, 2H, J = 7.2 Hz), 7.81(d, 2H, J = 6.8 Hz), 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] In dimethylformamide (36 g), compound [4] (3.64 g, 14.0 mmol), compound [11] (6.10 g) and potassium carbonate (2.91 g) were added, and the mixture was heated at 80°C. Stirred for 21 hours. After cooling to room temperature, pure water (72 g) was added to precipitate crystals. Compound [12] was obtained by filtering, slurry washing the filtrate with methanol (36 g), filtration, and drying the filtrate (yield: 5.80 g, yield: 83%, pale yellow crystals).
1H-NMR (400MHz, DMSO-d6, δppm): 9.44(s, 1H), 8.27(d, 2H, J = 7.2 Hz), 8.01(s, 1H), 7.94(d, 2H, J = 7.2 Hz) , 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 obtained crystal-containing liquid was filtered, and the filter cake was washed with methanol (60 g) as a slurry, filtered, and the filter cake was dried to obtain a crude product (4.3 g). Dimethylformamide (43 g) was added to the crude product, heated and stirred at 80°C, then methanol (43 g) was added, cooled, filtered, and the filtrate was dried to obtain compound [13] (yield : 4.13 g, yield: 89%, orange crystals).
1H-NMR (400MHz, DMSO-d6, δppm): 8.27(d, 2H, J = 6.8 Hz), 7.94(d, 2H, J = 6.8 Hz), 7.78(d, 2H, J = 6.8 Hz), 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 on carbon (0.41 g) were added to dimethylformamide (41 g), and the mixture was stirred at room temperature under a hydrogen atmosphere for 25 hours. did. After purging with nitrogen, dimethylformamide (82 g) was added and heated to 120° C., the catalyst was removed by filtration while hot, and the filtrate was concentrated to obtain a crude product (3.84 g). Dimethylformamide (19 g) was added to the crude product and dissolved by heating at 100° C., and then methanol (31 g) was added little by little and cooled to precipitate crystals. The obtained crystal-containing liquid was filtered and the filtered material was dried to obtain compound [DA-5] (yield: 3.33 g, yield: 87%, brown crystals).
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 synthesized by the same synthesis method as that of 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 synthesized by the same synthesis method as that of compound [DA-4] except that ethylene glycol ditosylate was changed to 1,3-propanediol ditosylate. -15] was obtained.

[viscosity]
Measurement was performed using an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.) with a sample volume of 1.1 mL, a cone rotor TE-1 (1° 34', R24), and a temperature of 25°C.
[Molecular weight]
It was measured using a GPC (normal temperature gel permeation chromatography) device, and the number average molecular weight (Mn) and weight average molecular weight (Mw) were calculated as polyethylene glycol and polyethylene oxide equivalent values.
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 for phosphoric acid/ _anhydrous crystal (o-phosphoric acid), 10 ml/L for tetrahydrofuran (THF)), flow rate: 1.0 ml/min Calibration curve creation Standard samples: TSK standard polyethylene oxide manufactured by Tosoh Corporation (weight average molecular weight (Mw) approximately 900,000, 150,000, 100,000, 30,000) and polyethylene glycol manufactured by Polymer Laboratory (peak top molecular weight (Mp) ) approx. 12,000, 4,000, 1,000). In order to avoid overlapping peaks, the measurement was carried out using a mixed sample of 4 types of 900,000, 100,000, 12,000, and 1,000, and a sample of 3 types of 150,000, 30,000, and 4,000. Two samples of the mixed sample were measured separately.

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

[Configuration of FFS drive liquid crystal cell]
A liquid crystal cell for fringe field switching (FFS) mode has a FOP (Finger on Plate) electrode layer formed on its surface, which consists of a planar common electrode, an insulating layer, and a comb-shaped pixel electrode. A pair of the glass substrate No. 1 and a second glass substrate having columnar spacers with a height of 4 μm on the front surface and an ITO film for preventing static electricity formed on the back surface were made into a set. The above pixel electrode has a comb-teeth 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 with an interval of 6 μm. It has a first region and a second region separated by a line connecting the bent portions of the plurality of electrode elements.
The liquid crystal alignment film formed on the first glass substrate is aligned so that the direction that equally divides the internal angle of the pixel bend and the alignment direction of the liquid crystal are perpendicular to each other, and the liquid crystal alignment film formed on the second glass substrate is The film is aligned so that the alignment direction of the liquid crystal on the first substrate matches the alignment direction of the liquid crystal on the second substrate when the liquid crystal cell is produced.

[Preparation of liquid crystal cell]
A liquid crystal aligning agent filtered through a filter with a pore size of 1.0 μm was applied on the surface of each of the above pair of glass substrates by spin coating, and dried on a hot plate at 80° C. for 2 minutes. After that, the coated film surface was irradiated with a predetermined amount of linearly polarized ultraviolet light with a wavelength of 254 nm with 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 form a liquid crystal film with a thickness of 100 nm. A substrate with an alignment film was obtained.
Next, a sealant was printed on one of the above-mentioned pair of glass substrates with a liquid crystal alignment film, and the other substrate was bonded 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., Ltd.) 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. Thereafter, the obtained liquid crystal cell was heated at 120° C. for 1 hour, 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 for 120 hours to the FFS-driven liquid crystal cell produced above in a constant temperature environment of 60°C. Thereafter, the pixel electrode and counter electrode of the liquid crystal cell were short-circuited, and the cell was left at room temperature for one day.
Regarding the liquid crystal cell subjected to the above treatment, the deviation between the orientation direction of the liquid crystal in the first region of the pixel and the orientation direction of the liquid crystal in the second region in a state where no voltage is applied was calculated as an angle.
Specifically, a liquid crystal cell is installed between two polarizing plates arranged so that the polarization axes are perpendicular to each other, the backlight is turned on, and the liquid crystal cell is set so that the intensity of transmitted light in the first area of the pixel is the smallest. The rotation angle required to rotate the liquid crystal cell so that the intensity of transmitted light in the second region of the pixel was minimized was determined.
It can be said that the smaller the value of this rotation angle, the better the afterimage characteristics due to long-term AC driving are. 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]
Examples of synthesis of polyamic acid and polyimide are shown below. In addition, in these nomenclatures, A is the (A) component, B is the (B) component, C is neither the (A) component nor the (B) component, and PI is polyimide. represents something.

<Synthesis example 1>
In a 200 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, add 1.95 g (8.00 mmol) of DA-1, 1.30 g (12.0 mmol) of DA-2, and 3.53 g (12.0 mmol) of DA-3. 12.0 mmol) and 1.90 g (8.00 mmol) of DA-7 were taken, 99.73 g of NMP was added thereto, and the mixture was stirred and dissolved while supplying 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 form 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>
Polyamic acid solutions (A-2) to (A-11) shown in Table 1 below were prepared in the same manner as Synthesis Example 1 except that the diamine component and tetracarboxylic acid component were changed to those shown in Table 1 below. ), (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 3L four-neck flask equipped with a stirrer and a nitrogen inlet tube, 50 g of NMP was added, and the mixture was stirred for 30 minutes. To the obtained polyamic acid solution, 16.30 g of acetic anhydride and 5.05 g of pyridine were added, and the mixture was heated at 50° C. for 3 hours to perform chemical imidization. The resulting reaction solution was poured into 600 ml of methanol with stirring, the precipitate was collected by filtration, the same operation was performed twice to wash the resin powder, and then dried at 60° C. for 12 hours. Thus, polyimide resin powder was obtained. The imidization rate 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 at 70°C for 24 hours to dissolve and form a polyimide solution (A-1- PI) was obtained (see Table 2 below).

<Synthesis Examples 13-15, 20-21>
Perform the same procedure as Synthesis Example 8, except that the polyamic shown in Table 2 below was used instead of the polyamic acid solution (A-1), and the imidization conditions were changed to those shown in Table 2 below. 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.

[Manufacture of liquid crystal alignment agent]
<Example 1>
50 ml of 4.0 g of the 12 mass % polyimide acid solution (A-1-PI) obtained in Synthesis Example 12 and 4.8 g of the 15 mass % polyamic acid solution (B-1) obtained in Synthesis Example 10. The mixture was placed in an Erlenmeyer flask, 1.20 g of NMP, 6.00 g of GBL, and 4.00 g of BCS were added thereto, 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 or precipitation were observed in this liquid crystal aligning agent, and it was confirmed that it was a uniform solution.

<Examples 2 to 16, Comparative Examples 1 to 2>
By carrying out in the same manner as in Example 1, except that the polyamic acid solution and 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). , liquid crystal alignment agents (2) to (18) were obtained. No abnormalities such as turbidity or precipitation were observed in these liquid crystal aligning agents, and it was confirmed that they were uniform solutions.

[Afterimage evaluation results due to long-term AC drive (when baking is performed before UV irradiation)]
<Example 21>
After filtering the liquid crystal alignment agent (1) of Example 1 through a filter with a pore size of 1.0 μm, the prepared substrate with the electrode and a glass substrate having a columnar spacer with a height of 4 μm on which an ITO film is formed on the back surface. It was applied by spin coating. After drying on a hot plate at 80° C. for 2 minutes, baking was performed in a hot air circulation oven at 230° C. for 30 minutes to form a coating film with a thickness of 100 nm. This coating surface was irradiated with linearly polarized ultraviolet rays with a wavelength of 254 nm with 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. . The above-mentioned two substrates obtained above are combined into a set, a sealant is printed on the substrate, and the other substrate is attached so that the liquid crystal alignment film surfaces face each other and the alignment direction is 0°, and then the seal is applied. The agent was cured to create an empty cell. Liquid crystal MLC-3019 (manufactured by Merck & Co., Ltd.) 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. Thereafter, the obtained liquid crystal cell was heated at 120° C. for 1 hour, left overnight, and afterimage evaluation by long-term AC driving was performed. The value of the angle Δ of this liquid crystal cell after long-term AC driving is 0.09° when the amount of ultraviolet rays irradiated is 200 mJ/cm ² , and 0.1° when the amount of ultraviolet rays is 300 mJ/cm ² Since both of these angles were 0.1° or less, good liquid crystal alignment was obtained using 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 amount of ultraviolet irradiation was changed to the amount of ultraviolet irradiation shown in Table 4 below. An FFS-driven liquid crystal cell was prepared in exactly the same manner as described above, and afterimage evaluation was performed by long-term AC driving. Table 4 shows the values of the angle Δ of this liquid crystal cell after long-term AC driving in each case.

[Results of afterimage evaluation due to long-term AC drive (when baking was not performed before UV irradiation)]
<Example 41>
After filtering with a filter with a pore size of 1.0 μm using the liquid crystal aligning agent (1) of Example 1, the prepared substrate with the electrode and a columnar spacer with 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 on a hot plate at 80°C for 2 minutes, the coating surface was irradiated with linearly polarized ultraviolet rays with a wavelength of 254 nm with an extinction ratio of 26:1 through a polarizing plate, and then heated in a hot air circulation oven at 230°C. It was baked for 30 minutes to obtain a substrate with a liquid crystal alignment film having a film thickness of 100 nm. The above-mentioned two substrates obtained above are combined into a set, a sealant is printed on the substrate, and the other substrate is attached so that the liquid crystal alignment film surfaces face each other and the alignment direction is 0°, and then the seal is applied. The agent was cured to create an empty cell. Liquid crystal MLC-3019 (manufactured by Merck & Co., Ltd.) 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. Thereafter, the obtained liquid crystal cell was heated at 120° C. for 1 hour, left overnight, and afterimage evaluation by long-term AC driving was performed. The value of the angle Δ of this liquid crystal cell after long-term AC driving is 0.07° when the amount of ultraviolet rays irradiated is 200 mJ/cm ² , and 0.07° when the amount of ultraviolet rays is 300 mJ/cm ² Since both of these angles were 0.1° or less, good liquid crystal alignment was obtained using 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 instead of the liquid crystal aligning agent (1) of Example 1, and the amount of ultraviolet irradiation was changed to the amount of ultraviolet irradiation shown in Table 5 below. An FFS-driven liquid crystal cell was prepared in exactly the same manner as described above, and afterimage evaluation was performed by long-term AC driving. Table 5 shows the values of the angle Δ of this liquid crystal cell after long-term AC driving in each case.

As shown in Tables 4 and 5, Examples 1 to 12 have an angle Δ (deg.) of 0.1° or less and have good afterimage characteristics, so they are useful for improving the display quality of liquid crystal display elements. Excellent.

The liquid crystal aligning agent of the present invention is used in a wide range of fields, such as large-sized liquid crystal display elements that require high definition and low cost, and mobile liquid crystal display elements 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 October 18, 2018 are cited here as disclosure of the specification of the present invention. , is something to be taken in.

Claims (10)

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

(In formula [1], A ₁ and A ₂ are each independently a monocyclic group or a fused ring group which may have a substituent, and A ₁ and A ₂ are simultaneously a monocyclic group. There is no _{such thing} . , each independently is an integer from 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. The liquid crystal aligning agent according to claim 1 or 2, wherein in the formula [1], 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 the structure represented by the formula [1] is one of the diamines shown below.

The liquid crystal aligning agent according to any one of claims 1 to 4, wherein the content of diamine having a structure represented by 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 formula [7], Z ₁ is a tetravalent organic group.) The liquid crystal aligning agent according to claim 6, wherein Z ₁ has a structure represented by any one 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.However, at least one of R ₃ to R ₆ is a group other than a hydrogen atom. be.) The liquid crystal aligning agent according to claim 7, wherein Z ₁ has a structure represented by formula (X1-1). A liquid crystal aligning film obtained from the liquid crystal aligning agent according to any one of claims 1 to 8. A liquid crystal display element comprising the liquid crystal alignment film according to claim 9.