JP5999107B2 - Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element - Google Patents

Description

  The present invention relates to a liquid crystal aligning agent for producing a liquid crystal aligning film, a liquid crystal aligning film obtained from the liquid crystal aligning agent, and a liquid crystal display element including the liquid crystal aligning film.

Currently, as a liquid crystal alignment film used for a liquid crystal display element, a liquid crystal alignment treatment agent (also referred to as a liquid crystal alignment agent) mainly composed of a polyimide precursor such as polyamic acid (also referred to as polyamic acid) or a solution of soluble polyimide is glass. A so-called polyimide liquid crystal alignment film that is applied to a substrate or the like and baked is mainly used.
A liquid crystal aligning agent using a polyimide precursor such as polyamic acid can be obtained simply by reacting a raw material tetracarboxylic dianhydride and a diamine compound in a solvent and diluting it to a concentration suitable for film formation. I can do it. However, since soluble polyimide needs to be chemically imidized after the production of a polyamic acid solution and the obtained polyimide powder is dissolved again in a solvent, the process is complicated and there is a problem in productivity. Therefore, it is preferable from the viewpoint of productivity if the liquid crystal alignment film using polyamic acid can satisfy various characteristics required for the liquid crystal alignment film.
However, a liquid crystal alignment film using a polyimide precursor such as polyamic acid generally has a problem in terms of voltage holding ratio and liquid crystal alignment, although the coating property to a glass substrate is good.

  A diamine compound containing a nitrogen-containing aromatic heterocycle in the side chain as a liquid crystal aligning agent that uses a polyimide precursor such as polyamic acid and has a high voltage holding ratio and quick relaxation of residual charges accumulated by DC voltage There has been proposed a liquid crystal aligning agent using slag (see Patent Document 1). However, in recent years, large-screen and high-definition liquid crystal televisions have been widely put into practical use, and liquid crystal display elements for such applications are required to have characteristics such as higher levels of liquid crystal orientation and voltage holding characteristics.

WO2009 / 093704

  An object of the present invention is to provide a liquid crystal alignment film using a polyamic acid, which has a high voltage holding ratio and excellent liquid crystal alignment.

（式（１）中、Ｘ₁は−Ｏ−、−ＮＱ^１−、−ＣＯＮＱ^１−、−ＮＱ^１ＣＯ−、−ＣＨ_２Ｏ−、及び−ＯＣＯ−からなる群より選ばれる少なくとも１種の２価の有機基であり、Ｑ^１は水素原子又は炭素数１〜３のアルキル基である。Ｘ_２は単結合、又は炭素数１〜２０の脂肪族炭化水素基、非芳香族環式炭化水素基、及び芳香族炭化水素基からなる群より選ばれる少なくとも１種の２価の有機基である。Ｘ_３は単結合、又は−Ｏ−、−ＮＱ^２−、−ＣＯＮＱ^２−、−ＮＱ^２ＣＯ−、−ＣＯＯ−、−ＯＣＯ−、及び−Ｏ（ＣＨ_２）_ｍ−（ｍは１〜５の整数である）からなる群より選ばれる少なくとも１種の２価の有機基であり、Ｑ^２は水素原子又は炭素数１〜３のアルキル基である。Ｘ_４は窒素含有の芳香族複素環基であり、ｎは１〜４の整数である。
式（２）中のnは、３〜１０の整数である。）
（２）前記ポリアミック酸の重量平均分子量が、５，０００〜１，０００，０００である上記（１）に記載の液晶配向剤。
（３）式（１）中のＸ_１が−Ｏ−、−ＮＱ^１−、−ＣＯＮＱ^１−、及び−ＮＱ^１ＣＯ−からなる群より選ばれる少なくとも１種であり、Ｘ_２が単結合、炭素数１〜３の直鎖アルキレン基、及びベンゼン環からなる群より選ばれる少なくとも１種であり、Ｘ_３が単結合、−ＯＣＯ−、及び−ＯＣＨ_２−からなる群より選ばれる少なくとも１種であり、Ｘ_４がイミダゾール環、ピリジン環、及びピリミジン環からなる群より選ばれる少なくとも１種であり、ｎが１又は２の整数である、上記（１）又は（２）に記載の液晶配向剤。
（４）式（１）のジアミンが、全ジアミン成分中５〜５０モル％である上記（１）〜（３）のいずれかに記載の液晶配向剤。
（５）式（１）中のＸ_４が、ピリジン環又はイミダゾール環である上記（１）〜（４）のいずれかに記載の液晶配向剤。
（６）式（２）のジアミンが、全ジアミン成分中１０〜５０モル％である上記（１）〜（５）のいずれかに記載の液晶配向剤。
（７）式（２）中のｎが、３〜８の整数である上記（１）〜（６）のいずれかに記載の液晶配向剤。
（８）前記テトラカルボン酸二無水物成分が、芳香族テトラカルボン酸二無水物をさらに含有する上記（１）〜（７）のいずれかに記載の液晶配向剤。As a result of diligent research to achieve the above object, the present inventor has used the above polyamic acid obtained by reacting a diamine compound using a plurality of specific diamines with tetracarboxylic dianhydride. I found that the problem could be solved. That is, the present invention is based on such knowledge and has the following gist.
(1) A diamine component containing a diamine compound of the following formulas (1) and (2), and a tetracarboxylic dianhydride component containing a tetracarboxylic dianhydride having an alicyclic structure or an aliphatic structure. Liquid crystal aligning agent containing the polyamic acid obtained by making it react.

(In the formula (1), X ₁ is ^{-O -, - NQ 1 -,} - CONQ 1 -, - NQ 1 CO -, - CH 2 O-, and at least one selected from the group consisting of -OCO- A divalent organic group, Q ¹ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, X ₂ is a single bond, an aliphatic hydrocarbon group having 1 to 20 carbon atoms, or a non-aromatic cyclic carbonization hydrogen radicals, and at least one divalent organic group selected from the group consisting of an aromatic hydrocarbon radical .X ₃ is a single bond or ^{-O -, - NQ 2 -,} - CONQ 2 -, - NQ ² CO—, —COO—, —OCO—, and —O (CH ₂ ) _m — (m is an integer of 1 to 5), and at least one divalent organic group selected from the group consisting of Q ² is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, X ₄ is a nitrogen-containing aromatic heterocyclic group, n Is an integer from 1 to 4.
N in Formula (2) is an integer of 3-10. )
(2) The liquid crystal aligning agent as described in said (1) whose weight average molecular weights of the said polyamic acid are 5,000-1,000,000.
(3) (1) _{X 1} in the ^{-O -, - NQ 1 -,} - CONQ 1 -, and at least one selected from the group consisting of ^-NQ 1 CO-, _{X 2} is a single bond, linear alkylene group having 1 to 3 carbon atoms, and at least one selected from the group consisting of benzene ring, _{X 3} is a single bond, -OCO-, and -OCH ₂ -, at least one selected from the group consisting of The liquid crystal alignment according to (1) or (2), wherein X ₄ is at least one selected from the group consisting of an imidazole ring, a pyridine ring, and a pyrimidine ring, and n is an integer of 1 or 2. Agent.
(4) The liquid crystal aligning agent in any one of said (1)-(3) whose diamine of Formula (1) is 5-50 mol% in all the diamine components.
(5) (1) X ₄ in the liquid crystal alignment agent according to any one of the above is a pyridine ring or an imidazole ring (1) to (4).
(6) The liquid crystal aligning agent in any one of said (1)-(5) whose diamine of Formula (2) is 10-50 mol% in all the diamine components.
(7) The liquid crystal aligning agent in any one of said (1)-(6) whose n in Formula (2) is an integer of 3-8.
(8) The liquid crystal aligning agent in any one of said (1)-(7) in which the said tetracarboxylic dianhydride component further contains aromatic tetracarboxylic dianhydride.

(9) A liquid crystal alignment film obtained using the liquid crystal aligning agent according to any one of (1) to (8).
(10) The liquid crystal alignment film according to (9), wherein the liquid crystal alignment agent contains 80 to 99% by mass of an organic solvent with respect to the entire liquid crystal alignment agent (100% by mass).
(11) The organic solvent is N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 2-pyrrolidone, N-ethylpyrrolidone, N-vinylpyrrolidone, dimethyl Sulfoxide, tetramethylurea, pyridine, dimethylsulfone, hexamethylsulfoxide, γ-butyrolactone, 1,3-dimethyl-imidazolidinone, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, cyclohexanone, ethylene The liquid crystal alignment film according to (10), which is at least one selected from the group consisting of carbonate, propylene carbonate, diglyme, and 4-hydroxy-4-methyl-2-pentanone.
(12) A liquid crystal display device comprising the liquid crystal alignment film according to any one of (9) to (11).

  According to the present invention, it is possible to provide a polyamic acid-based liquid crystal alignment film having a good voltage holding characteristic and a better liquid crystal alignment characteristic than before.

The present invention is described in detail below.
The present invention relates to a diamine component containing a diamine compound represented by formula (1) (also referred to as specific diamine compound 1) and a diamine compound represented by formula (2) (also referred to as specific diamine compound 2), and an alicyclic ring. A liquid crystal aligning agent containing a polyamic acid obtained using a tetracarboxylic dianhydride component containing a tetracarboxylic dianhydride having a formula structure or an aliphatic structure as a raw material, and a liquid crystal alignment obtained using the liquid crystal aligning agent It is a liquid crystal display element which has a film | membrane and also this liquid crystal aligning film.

式［１］中、Ｘ₁は−Ｏ−、−ＮＱ^１−、−ＣＯＮＱ^１−、−ＮＱ^１ＣＯ−、−ＣＨ_２Ｏ−、及び−ＯＣＯ−からなる群より選ばれる少なくとも１種の２価の有機基であり、Ｑ^１は水素原子又は炭素数１〜３のアルキル基である。
Ｘ_２は単結合、又は炭素数１〜２０の脂肪族炭化水素基、非芳香族環式炭化水素基、及び芳香族炭化水素基からなる群より選ばれる少なくとも１種の２価の有機基である。
Ｘ_３は単結合、又は−Ｏ−、−ＮＱ^２−、−ＣＯＮＱ^２−、−ＮＱ^２ＣＯ−、−ＣＯＯ−、−ＯＣＯ−、及び−Ｏ（ＣＨ_２）_ｍ−（ｍは１〜５の整数である）からなる群より選ばれる少なくとも１種の２価の有機基であり、Ｑ^２は水素原子又は炭素数１〜３のアルキル基である。
Ｘ_４は窒素含有の芳香族複素環基であり、ｎは１〜４の整数である。
式（１）で表される化合物の全ジアミン成分中における好ましい含有量は、５〜５０モル％であり、より好ましくは１０〜４０モル％である。<Specific diamine compound 1>
The specific diamine compound 1 used for the liquid crystal aligning agent of this invention is a diamine compound represented by following formula (1).

Wherein [1], X ₁ is ^{-O -, - NQ 1 -,} - CONQ 1 -, - NQ 1 CO -, - CH 2 O-, and at least one 2 selected from the group consisting of -OCO- Q ¹ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.
X ₂ is a single bond or at least one divalent organic group selected from the group consisting of an aliphatic hydrocarbon group having 1 to 20 carbon atoms, a non-aromatic cyclic hydrocarbon group, and an aromatic hydrocarbon group. is there.
X ₃ is a single bond or ^{-O -, - NQ 2 -,} - CONQ 2 -, - NQ 2 CO -, - COO -, - OCO-, and _{-O (CH 2) m - (} m is 1-5 at least one divalent organic group of selected from the group consisting of integer is), Q ² is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.
X ₄ is a nitrogen-containing aromatic heterocyclic group, and n is an integer of 1 to 4.
The preferable content in the total diamine component of the compound represented by Formula (1) is 5 to 50 mol%, more preferably 10 to 40 mol%.

The bonding position of the two amino groups (—NH ₂ ) in Formula (1) is not limited.
Specifically, when n is 1, with respect to the side chain linking group (X ₁ ), 2, 3 positions, 2, 4 positions, 2, 5 positions, 2, 6 positions on the benzene ring The position, the position of 3, 4 and the position of 3, 5 are mentioned.
In the case where n is 2, for example, when the other linking group (X ₁ ) is in the 2 position on the benzene ring with respect to the linking group (X ₁ ) on the side chain, the two amino groups are bonded. Examples of the position include positions 3, 4, 3, 5, 5, 6, and 4, 5. Further, when the other linking group (X ₁ ) is at position 3 on the benzene ring with respect to the linking group (X ₁ ) on the side chain, the bonding positions of the two amino groups are positions 2, 4 , 2, 5 positions, 4, 5 positions, and 4, 6 positions. Moreover, other one of the binding group for binding group (X ₁₎ of the side chain (X ₁₎ is, when in the 4 position on the benzene ring, relative to the binding group of the side chain (X _1), Examples of the bonding positions of the two amino groups include positions 2, 3, 2, 5, 2, 6, and 3, 5.
In the case where n is 3, for example, when the other two linking groups (X ₁ ) are located at 2, 3 positions on the benzene ring with respect to the side chain linking group (X ₁ ), two amino groups Examples of the bonding position are 4 and 5 positions and 4 and 6 positions. When the other two linking groups (X ₁ ) are located at the 2,4 positions on the benzene ring with respect to the side chain linking group (X ₁ ), the bonding positions of the two amino groups are 3, 5 position, 3 and 6 position, and 5 and 6 position. Further, when the other two linking groups (X ₁ ) are located at positions 3 and 5 on the benzene ring with respect to the side chain linking group (X ₁ ), the bonding positions of the two amino groups are 2, 4 positions.

When n is 4, for example, when the other three linking groups (X ₁ ) are located at 2, 3, and 4 positions on the benzene ring with respect to the side chain linking group (X ₁ ), Examples of the binding position of the amino group include positions 5 and 6. Further, when the other three bonding groups (X ₁ ) are located at positions 2, 4, and 5 on the benzene ring with respect to the side chain bonding group (X ₁ ), the bonding positions of the two amino groups are There are 3 and 6 positions. Furthermore, when the other three linking groups (X ₁ ) are located at 2, 4 and 6 positions on the benzene ring with respect to the side chain linking group (X ₁ ), the bonding positions of the two amino groups are: There are 3 and 5 positions.
Among these, from the viewpoint of reactivity when synthesizing a polyamic acid and from the viewpoint of ease of synthesizing a diamine compound, when n is 1, the binding position of two amino groups is 2,4. The other linking group (X ₁ ) on the benzene ring with respect to the linking group (X ₁ ) of the side chain in the position, 2, 5 position, 3, 5 position, or when n is 2 is In the case of the position 3, the position where the bonding positions of the two amino groups are 4, 6 is particularly preferable.

中でも、式［１ａ］、式［１ｂ］、式［１ｃ］、式［１ｄ］で表される化合物が好ましい。なお、Ｑ^１は、式［１］の定義と同意義である。Wherein [1], _{X 1} is ^{-O -, - NQ 1 -,} - CONQ 1 -, - NQ 1 CO -, - CH 2 O-, and at least one 2 selected from the group consisting of -OCO- Valent organic group. Among ^{them, -O -, - NQ 1 -} , - CONQ 1 -, - NQ 1 CO- is preferred. Q ¹ has the same meaning as defined in formula [1].
Specific examples of the compound having a preferable X ₁ structure include the following formulas [1a] to [1f].

Among these, compounds represented by the formula [1a], the formula [1b], the formula [1c], and the formula [1d] are preferable. Q ¹ has the same meaning as defined in formula [1].

In the formula [1], X ₂ is a single bond or at least one selected from the group consisting of an aliphatic hydrocarbon group having 1 to 20 carbon atoms, a non-aromatic cyclic hydrocarbon group, and an aromatic hydrocarbon group. It is a divalent organic group.
The aliphatic hydrocarbon group having 1 to 20 carbon atoms may be linear or branched. Moreover, you may have an unsaturated bond. Preferably it is a C1-C10 aliphatic hydrocarbon group.
Specific examples of the non-aromatic cyclic hydrocarbon group include cyclopropane ring, cyclobutane ring, cyclopentane ring, cyclohexane ring, cycloheptane ring, cyclooctane ring, cyclononane ring, cyclodecane ring, cycloundecane ring, cyclododecane ring, Cyclotridecane ring, cyclotetradecane ring, cyclopentadecane ring, cyclohexadecane ring, cycloheptadecane ring, cyclooctadecane ring, cyclononadecane ring, cycloicosane ring, tricycloeicosane ring, tricyclodecosan ring, bicycloheptane ring, decahydro A naphthalene ring, a norbornene ring, an adamantane ring, etc. are mentioned.
Specific examples of the aromatic hydrocarbon group include a benzene ring, naphthalene ring, tetrahydronaphthalene ring, azulene ring, indene ring, fluorene ring, anthracene ring, phenanthrene ring, and phenalene ring.

Preferred X ₂ in the formula [1] is a single bond, a linear or branched alkylene group having 1 to 10 carbon atoms, an unsaturated alkylene group having 1 to 10 carbon atoms, a cyclopropane ring, a cyclobutane ring, or a cyclopentane ring. A cyclohexane ring, a cycloheptane ring, a norbornene ring, an adamantane ring, a benzene ring, a naphthalene ring, a tetrahydronaphthalene ring, a fluorene ring, and an anthracene ring, more preferably a single bond, a straight chain or branched chain having 1 to 10 carbon atoms. An alkylene group, an unsaturated alkylene group having 1 to 10 carbon atoms, a cyclohexane ring, a norbornene ring, an adamantane ring, a benzene ring, a naphthalene ring, a fluorene ring, and an anthracene ring, and more preferably a single bond and a carbon number of 1 to 10 Linear or branched alkylene group, cyclohexane ring, benzene ring, naphthalene Particularly preferred are a single bond, a linear or branched alkylene group having 1 to 5 carbon atoms, and a benzene ring. Most preferably, they are a single bond, a C1-C3 linear alkylene group, or a benzene ring.

式［２ｃ］中、Ｙ_１は炭素数１〜５の直鎖又は分岐したアルキル基である。Wherein [1], _{X 3} is a single bond or ^{-O -, - NQ 2 -,} - CONQ 2 -, - NQ 2 CO -, - COO -, - OCO-, and -O _{(CH 2) m} - (M is an integer of 1 to 5) is at least one divalent organic group selected from the group consisting of a single bond, —O—, —CONQ ² —, —NQ ² CO—, —COO—, —OCO—, —O (CH ₂ ) _m — (m is an integer of 1 to 5). Most preferably, a single bond, -OCO -, - OCH ₂ - is. Q ² has the same meaning as defined in formula [1].
In the formula [1], X ₄ is a nitrogen-containing aromatic heterocyclic group and contains at least one structure selected from the group consisting of the following formulas [2a], [2b] and [2c]. A nitrogen-containing aromatic heterocyclic group.

In formula [2c], Y ₁ is a linear or branched alkyl group having 1 to 5 carbon atoms.

Preferable X ₄ in the formula [1] is a pyrrole ring, imidazole ring, oxazole ring, thiazole ring, pyrazole ring, pyridine ring, pyrimidine ring, quinoline ring, pyrazoline ring, isoquinoline ring, carbazole ring, purine ring, thiadiazole ring. , Pyridazine ring, pyrazoline ring, triazine ring, pyrazolidine ring, triazole ring, pyrazine ring, benzimidazole ring, benzimidazole ring, tinoline ring, phenanthroline ring, indole ring, quinoxaline ring, benzothiazole ring, phenothiazine ring, oxadiazole ring Acridine ring, more preferably pyrrole ring, imidazole ring, pyrazole ring, pyridine ring, pyrimidine ring, pyrazoline ring, carbazole ring, pyridazine ring, pyrazoline ring, triazine ring, pyrazolidine ring , Triazole ring, pyrazine ring, benzimidazole ring, benzimidazole ring, more preferably pyrrole ring, imidazole ring, pyrazole ring, pyridine ring, pyrimidine ring, pyridazine ring, triazine ring, triazole ring, pyrazine ring, benz An imidazole ring and a benzimidazole ring are preferable, and a pyrrole ring, an imidazole ring, a pyrazole ring, a pyridine ring, and a pyrimidine ring are particularly preferable. Most preferably, they are an imidazole ring, a pyridine ring, and a pyrimidine ring.

  In the formula [1], n is an integer of 1 to 4, and preferably an integer of 1 to 3 from the viewpoint of reactivity with tetracarboxylic dianhydride. Most preferably, n is an integer of 1 or 2.

A preferred combination of _{X 1, X 2, X 3} , X 4 and n in the formula [1], _{X 1} is ^{-O -, - NQ 1 -,} - CONQ 1 -, - NQ 1 CO -, - CH 2 O -And -OCO-, and at least one selected from the group consisting of -OCO-, wherein X ₂ is a linear or branched alkylene group having 1 to 10 carbon atoms, an unsaturated alkylene group having 1 to 10 carbon atoms, a cyclopropane ring, X ₃ is at least one selected from the group consisting of cyclobutane ring, cyclopentane ring, cyclohexane ring, cycloheptane ring, norbornene ring, adamantane ring, benzene ring, naphthalene ring, tetrahydronaphthalene ring, fluorene ring, and anthracene ring. but a single ^{bond, -O -, - NQ 2 -} , - CONQ 2 -, - NQ 2 CO -, - COO -, - OCO-, and -O _{(CH 2)} m - ₍ m is at least one selected from the group consisting of 1 to 5), and X ₄ is a pyrrole ring, imidazole ring, oxazole ring, thiazole ring, pyrazole ring, pyridine ring, pyrimidine ring, quinoline ring, pyrazoline. Ring, isoquinoline ring, carbazole ring, purine ring, thiadiazole ring, pyridazine ring, pyrazoline ring, triazine ring, pyrazolidine ring, triazole ring, pyrazine ring, benzimidazole ring, benzimidazole ring, tinoline ring, phenanthroline ring, indole ring, quinoxaline It is at least one selected from the group consisting of a ring, a benzothiazole ring, a phenothiazine ring, an oxadiazole ring, and an acridine ring, and n is an integer of 1 or 2.

More preferably _X 1 in the formula _{[1], X 2, X} 3, X 4 and n combinations of, _{X 1} is ^{-O -, - NQ 1 -,} - CONQ 1 -, - NQ 1 CO-, and -CH _It is at least one selected from the group consisting of ₂ O—, and X ₂ is a linear or branched alkylene group having 1 to 10 carbon atoms, an unsaturated alkylene group having 1 to 10 carbon atoms, a cyclohexane ring, a norbornene ring, an adamantane ring, a benzene ring, a naphthalene ring, a fluorene ring, and at least one selected from the group consisting of an anthracene ring, _{X 3} is a single ^{bond, -O -, - NQ 2 -} , - CONQ 2 -, - NQ 2 CO —, —COO—, —OCO—, and —O (CH ₂ ) _m — (m is an integer of 1 to 5), and X ₄ is a pyrrole ring or an imidazole ring. , At least one selected from the group consisting of a azole ring, a pyridine ring, a pyrimidine ring, a pyrazoline ring, a carbazole ring, a pyridazine ring, a pyrazoline ring, a triazine ring, a pyrazolidine ring, a triazole ring, a pyrazine ring, a benzimidazole ring, and a benzimidazole ring. And n is an integer of 1 or 2.

Further preferred compounds of formula _X 1 in _{[1], X 2, X} 3, the combination of _{X 4} and n, _{X 1} is ^{-O -, - NQ 1 -,} - CONQ 1 -, - NQ 1 CO -, - CH 2 A group consisting of at least one selected from the group consisting of O- and -OCO-, wherein X ₂ is a linear or branched alkylene group having 1 to 10 carbon atoms, a cyclohexane ring, a benzene ring, and a naphthalene ring. is more least one selected, _{X 3} is a single ^{bond, -O -, - CONQ 2 -} , - NQ 2 CO -, - COO -, - OCO-, and _{-O (CH 2) m - (} m is 1 is an integer of 1 to 5, and X ₄ is a pyrrole ring, imidazole ring, pyrazole ring, pyridine ring, pyrimidine ring, pyridazine ring, triazine ring, triazole ring, pyrazine ring, Be 'S imidazole ring, and at least one selected from the group consisting of benzimidazole ring, n is an integer of 1 or 2.
Particularly preferred _{X 1, X 2, X 3} , the combination of _{X 4} and n in the formula [1], _{X 1} is ^{-O -, - NQ 1 -,} - CONQ 1 -, - NQ 1 CO-, and -CH Is at least one selected from the group consisting of ₂ O-, and X ₂ is at least one selected from the group consisting of a single bond, a linear or branched alkylene group having 1 to 5 carbon atoms, and a benzene ring, X ₃ is a single ^{bond, -O -, - CONQ 2 -} , - NQ 2 CO -, - COO -, - OCO-, and -O _{(CH 2)} m - from (m is an integer of 1 to 5) X ₄ is at least one selected from the group consisting of a pyrrole ring, an imidazole ring, a pyrazole ring, a pyridine ring, and a pyrimidine ring, and n is an integer of 1 or 2. .

The most preferred _X 1 in the formula _{[1], X 2, X} 3, X 4 and n combinations of, _{X 1} is ^{-O -, - NQ 1 -,} - CONQ 1 -, and the group consisting of ^-NQ 1 CO- more is at least one selected, X ₂ is a single bond, a straight-chain alkylene group having 1 to 3 carbon atoms, and at least one selected from the group consisting of benzene ring, X ₃ is a single bond, -OCO- And at least one selected from the group consisting of —OCH ₂ —, X ₄ is at least one selected from the group consisting of an imidazole ring, a pyridine ring, and a pyrimidine ring, and n is an integer of 1 or 2. is there.
Particularly preferred combinations of X ₁ , X ₂ , X ₃ , X ₄ and n in the formula [1] are as shown in Tables 1 to 3 below. Q ¹ and Q ² are the same as defined in formula [1].

式（２）中、ｎは３〜１０の整数であるが、液晶配向性の観点から、好ましくは３〜８であり、より好ましくは５〜７である。
式（２）で表される化合物の全ジアミン成分中における好ましい含有量は、１０〜６０モル％であり、より好ましくは４０〜６０モル％である。<Specific diamine compound 2>
The specific diamine compound 2 used for the liquid crystal aligning agent of this invention is a diamine compound represented by following formula (2).

In formula (2), n is an integer of 3 to 10, preferably 3 to 8, more preferably 5 to 7, from the viewpoint of liquid crystal alignment.
The preferable content in the total diamine component of the compound represented by Formula (2) is 10 to 60 mol%, more preferably 40 to 60 mol%.

<Other diamine compounds>
In the present invention, a diamine other than the specific diamine compound (hereinafter also referred to as other diamine compound) can be used in combination as long as the effects of the present invention are not impaired, and the other diamine compound is not particularly limited. Specific examples are shown below.
p-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, m-phenylenediamine, 2,4-dimethyl-m-phenylenediamine, 2, 5-diaminotoluene, 2,6-diaminotoluene, 2,5-diaminophenol, 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4 , 6-diaminoresorcinol, 4,4′-diaminobiphenyl, 3,3′-dimethyl-4,4′-diaminobiphenyl, 3,3′-dimethoxy-4,4′-diaminobiphenyl, 3,3′-dihydroxy -4,4'-diaminobiphenyl, 3,3'-difluoro-4,4'-biphenyl, 3,3'-trifluorome Til-4,4′-diaminobiphenyl, 3,4′-diaminobiphenyl, 3,3′-diaminobiphenyl, 2,2′-diaminobiphenyl, 2,3′-diaminobiphenyl, 4,4′-diaminodiphenylmethane, 3,3′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 2,2′-diaminodiphenylmethane, 2,3′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether, 3,3′-diaminodiphenyl ether, 3, 4'-diaminodiphenyl ether, 2,2'-diaminodiphenyl ether, 2,3'-diaminodiphenyl ether, 4,4'-sulfonyldianiline, 3,3'-sulfonyldianiline, bis (4-aminophenyl) silane, bis (3-aminophenyl) silane, dimethyl-bis (4-aminophen ) Silane, dimethyl-bis (3-aminophenyl) silane, 4,4'-thiodianiline, 3,3'-thiodianiline, 4,4'-diaminodiphenylamine, 3,3'-diaminodiphenylamine, 3,4'- Diaminodiphenylamine, 2,2′-diaminodiphenylamine, 2,3′-diaminodiphenylamine, N-methyl (4,4′-diaminodiphenyl) amine, N-methyl (3,3′-diaminodiphenyl) amine, N-methyl (3,4'-diaminodiphenyl) amine, N-methyl (2,2'-diaminodiphenyl) amine, N-methyl (2,3'-diaminodiphenyl) amine, 4,4'-diaminobenzophenone, 3,3 '-Diaminobenzophenone, 3,4'-diaminobenzophenone, 1,4-diaminonaphthalene, 2,2'-diamino Nzophenone, 2,3′-diaminobenzophenone, 1,5-diaminonaphthalene, 1,6-diaminonaphthalene, 1,7-diaminonaphthalene, 1,8-diaminonaphthalene, 2,5-diaminonaphthalene, 2,6 diaminonaphthalene 2,7-diaminonaphthalene, 2,8-diaminonaphthalene, 1,2-bis (4-aminophenyl) ethane, 1,2-bis (3-aminophenyl) ethane, 1,3-bis (4-amino) Phenyl) propane, 1,3-bis (3-aminophenyl) propane, 1,4-bis (4aminophenyl) butane, 1,4-bis (3-aminophenyl) butane, bis (3,5-diethyl- 4-aminophenyl) methane, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1 , 4-Bis (4-aminophenyl) benzene, 1,3-bis (4-aminophenyl) benzene, 1,4-bis (4-aminobenzyl) benzene, 1,3-bis (4-aminophenoxy) benzene 4,4 ′-[1,4-phenylenebis (methylene)] dianiline, 4,4 ′-[1,3-phenylenebis (methylene)] dianiline, 3,4 ′-[1,4-phenylenebis ( Methylene)] dianiline, 3,4 ′-[1,3-phenylenebis (methylene)] dianiline, 3,3 ′-[1,4-phenylenebis (methylene)] dianiline, 3,3 ′-[1,3 -Phenylenebis (methylene)] dianiline, 1,4-phenylenebis [(4-aminophenyl) methanone], 1,4-phenylenebis [(3-aminophenyl) methanone], 1,3-phenylenebis [(4 -Aminophenyl) methanone], 1,3-phenylenebis [(3-aminophenyl) methanone], 1,4-phenylenebis (4-aminobenzoate), 1,4-phenylenebis (3-aminobenzoate), 1 , 3-phenylenebis (4-aminobenzoate), 1,3-phenylenebis (3-aminobenzoate), bis (4-aminophenyl) terephthalate, bis (3-aminophenyl) terephthalate, bis (4-aminophenyl) Isophthalate, bis (3-aminophenyl) isophthalate, N, N ′-(1,4-phenylene) bis (4-aminobenzamide), N, N ′-(1,3-phenylene) bis (4-amino) Benzamide), N, N ′-(1,4-phenylene) bis (3-aminobenzamide), N, N ′-(1,3-phen Nylene) bis (3-aminobenzamide), N, N′-bis (4-aminophenyl) terephthalamide, N, N′-bis (3-aminophenyl) terephthalamide, N, N′-bis (4-amino) Phenyl) isophthalamide, N, N′-bis (3-aminophenyl) isophthalamide, 9,10-bis (4-aminophenyl) anthracene, 4,4′-bis (4-aminophenoxy) diphenylsulfone, 2, 2'-bis [4- (4-aminophenoxy) phenyl] propane, 2,2'-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2'-bis (4-aminophenyl) Hexafluoropropane, 2,2′-bis (3-aminophenyl) hexafluoropropane, 2,2′-bis (3-amino-4-methylphenyl) hexa Fluoropropane, 2,2′-bis (4-aminophenyl) propane, 2,2′-bis (3-aminophenyl) propane, 2,2′-bis (3-amino-4-methylphenyl) propane, 1 , 3-bis (4-aminophenoxy) propane, 1,3-bis (3-aminophenoxy) propane, 1,4-bis (4-aminophenoxy) butane, 1,4-bis (3-aminophenoxy) butane 1,5-bis (4-aminophenoxy) pentane, 1,5-bis (3-aminophenoxy) pentane, 1,6-bis (4-aminophenoxy) hexane, 1,6-bis (3-amino) Phenoxy) hexane, 1,7-bis (4-aminophenoxy) heptane, 1,7- (3-aminophenoxy) heptane, 1,8-bis (4-aminophenoxy) octane, 1, -Bis (3-aminophenoxy) octane, 1,9-bis (4-aminophenoxy) nonane, 1,9-bis (3-aminophenoxy) nonane, 1,10- (4-aminophenoxy) decane, 1, 10- (3-aminophenoxy) decane, 1,11- (4-aminophenoxy) undecane, 1,11- (3-aminophenoxy) undecane, 1,12- (4-aminophenoxy) dodecane, 1,12- (3-Aminophenoxy) dodecane. Bis (4-aminocyclohexyl) methane, bis (4-amino-3-methylcyclohexyl) methane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane and the like.

（式［ＤＡ１］〜式［ＤＡ５］中、Ｒ_１は、炭素数１以上２２以下の、アルキル基又はフッ素含有アルキル基である。Moreover, the diamine which has an alkyl group, a fluorine-containing alkyl group, an aromatic ring, an aliphatic ring, a heterocyclic ring, and a macrocyclic substituent consisting of them in the diamine side chain can be exemplified. Specifically, diamine compounds represented by the following formulas [DA1] to [DA26] can be exemplified.

(In Formula [DA1] to Formula [DA5], R ₁ is an alkyl group or a fluorine-containing alkyl group having 1 to 22 carbon atoms.

（式［ＤＡ６］〜式［ＤＡ９］中、Ｒ_２は、−ＣＯＯ−、−ＯＣＯ−、−ＣＯＮＨ−、−ＮＨＣＯ−、−ＣＨ_２−、−Ｏ−、−ＣＯ−、又は−ＮＨ−であり、Ｒ_３は、炭素数１以上２２以下の、アルキル基又はフッ素含有アルキル基である。）

(In Formula [DA6] to Formula [DA9], R ₂ represents —COO—, —OCO—, —CONH—, —NHCO—, —CH ₂ —, —O—, —CO—, or —NH—. And R ₃ is an alkyl group or a fluorine-containing alkyl group having 1 to 22 carbon atoms.)

（式［ＤＡ１０］及び式［ＤＡ１１］中、Ｒ_４は、−Ｏ−、−ＯＣＨ_２−、−ＣＨ_２Ｏ−、−ＣＯＯＣＨ_２−、又は−ＣＨ_２ＯＣＯ−であり、Ｒ_５は、炭素数１以上２２以下の、アルキル基、アルコキシ基、フッ素含有アルキル基又はフッ素含有アルコキシ基である。）

（式［ＤＡ１２］〜式［ＤＡ１４］中、Ｒ_６は、−ＣＯＯ−、−ＯＣＯ−、−ＣＯＮＨ−、−ＮＨＣＯ−、−ＣＯＯＣＨ_２−、−ＣＨ_２ＯＣＯ−、−ＣＨ_２Ｏ−、−ＯＣＨ_２−、又は−ＣＨ_２−であり、Ｒ_７は、炭素数１以上２２以下の、アルキル基、アルコキシ基、フッ素含有アルキル基又はフッ素含有アルコキシ基である。）

(In Formula [DA10] and Formula [DA11], R ₄ is —O—, —OCH ₂ —, —CH ₂ O—, —COOCH ₂ —, or —CH ₂ OCO—, and R ₅ is carbon. An alkyl group, an alkoxy group, a fluorine-containing alkyl group or a fluorine-containing alkoxy group having a number of 1 or more and 22 or less.

(In Formula [DA12] to Formula [DA14], R ₆ represents —COO—, —OCO—, —CONH—, —NHCO—, —COOCH ₂ —, —CH ₂ OCO—, —CH ₂ O—, — OCH ₂ — or —CH ₂ —, and R ₇ is an alkyl group, alkoxy group, fluorine-containing alkyl group or fluorine-containing alkoxy group having 1 to 22 carbon atoms.

（式［ＤＡ１５］及び式［ＤＡ１６］中、Ｒ_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。）

(In Formula [DA15] and Formula [DA16], R ₈ represents —COO—, —OCO—, —CONH—, —NHCO—, —COOCH ₂ —, —CH ₂ OCO—, —CH ₂ O—, — OCH ₂ —, —CH ₂ —, —O—, or —NH—, and R ₉ represents 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 It is a hydroxyl group.)

加えて、下記の式［ＤＡ２７］で示されるようなジアミノシロキサンなども挙げることができる。

（式［ＤＡ２７］中、ｍは、１〜１０の整数である。）
その他のジアミン化合物は、液晶配向膜とした際の液晶配向性、電圧保持特性、蓄積電荷などの特性に応じて、１種類又は２種類以上を混合して使用することもできる。

In addition, diaminosiloxanes represented by the following formula [DA27] can also be exemplified.

(In the formula [DA27], m is an integer of 1 to 10.)
Other diamine compounds may be used alone or in combination of two or more depending on the liquid crystal alignment properties, voltage holding characteristics, accumulated charge, and the like when the liquid crystal alignment film is formed.

<Tetracarboxylic dianhydride>
The tetracarboxylic dianhydride component that is reacted with the diamine component to obtain the polyamic acid contained in the liquid crystal aligning agent of the present invention contains a tetracarboxylic dianhydride having an alicyclic structure or an aliphatic structure.
Examples of the tetracarboxylic dianhydride having an alicyclic structure or an aliphatic structure include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutane. Tetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetra Carboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic Acid dianhydride, 3,4-dicarboxy-1-cyclohexyl succinic dianhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic dianhydride, 1, , 3,4-Butanetetracarboxylic dianhydride, bicyclo [3,3,0] octane-2,4,6,8-tetracarboxylic dianhydride, 3,3 ′, 4,4′-dicyclohexyltetra Carboxylic dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, cis-3,7-dibutylcycloocta-1,5-diene-1,2,5,6-tetracarboxylic dianhydride , Tricyclo [4.2.1.02,5] nonane-3,4,7,8-tetracarboxylic acid-3,4: 7,8-dianhydride, hexacyclo [6.6.0.12,7 .03, 6.19, 14.010, 13] hexadecane-4,5,11,12-tetracarboxylic acid-4,5: 11,12-dianhydride, 4- (2,5-dioxotetrahydrofuran- 3-yl) -1,2,3,4-tetrahydronaphth Examples include tarene-1,2-dicarboxylic acid anhydride.
Among them, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 3,4-dicarboxy-1- Cyclohexyl succinic dianhydride, 1,2,3,4-butanetetracarboxylic dianhydride, bicyclo [3,3,0] octane-2,4,6,8-tetracarboxylic dianhydride, 2, 3,5-tricarboxycyclopentyl acetic acid dianhydride and the like are preferable.

In addition to the tetracarboxylic dianhydride having the alicyclic structure or aliphatic structure, the use of aromatic tetracarboxylic dianhydride improves the liquid crystal alignment and reduces the accumulated charge of the liquid crystal cell. Can do.
As aromatic tetracarboxylic dianhydride, pyromellitic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,2 ′, 3,3′-biphenyltetracarboxylic acid Dianhydride, 2,3,3 ′, 4-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, 2,3,3 ′, 4-benzophenonetetra Carboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride Products, 2,3,6,7-naphthalenetetracarboxylic dianhydride and the like.
Of these, pyromellitic dianhydride, 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride, 2,3,3 ′, 4-biphenyltetracarboxylic dianhydride, and the like are preferable.
The aromatic tetracarboxylic dianhydride is preferably contained in an amount of 0 to 50 mol%, more preferably 0 to 30 mol%, based on the total tetracarboxylic dianhydride.

The tetracarboxylic dianhydride component can be used alone or in combination of two or more depending on the liquid crystal alignment properties, voltage holding characteristics, accumulated charge, and the like when the liquid crystal alignment film is formed.
The tetracarboxylic dianhydride having an alicyclic structure or an aliphatic structure is preferably 50 mol% or more, and more preferably 70 mol% or more in the total tetracarboxylic dianhydride component. Particularly preferred is 75 to 100 mol%.

<Synthesis of polyamic acid>
By the reaction of the tetracarboxylic dianhydride component containing a tetracarboxylic dianhydride having an alicyclic structure or an aliphatic structure with the diamine component containing the specific diamine components 1 and 2, the liquid crystal aligning agent of the present invention is used. In obtaining the contained polyamic acid, a known synthesis method can be used.
In general, the tetracarboxylic dianhydride component and the diamine component are reacted in an organic solvent. The reaction of tetracarboxylic dianhydride and diamine is advantageous in that it proceeds relatively easily in an organic solvent and no by-product is generated.

The organic solvent used for the reaction between tetracarboxylic dianhydride and diamine is not particularly limited as long as the produced polyamic acid can be dissolved. Specific examples are given below.
N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, dimethylsulfoxide, tetramethylurea, pyridine, dimethylsulfone, hexamethylsulfoxide, 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 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, methyl pyruvate, ethyl pyruvate, 3 -Methyl methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, Examples include propyl 3-methoxypropionate, butyl 3-methoxypropionate, diglyme, 4-hydroxy-4-methyl-2-pentanone, and the like. These may be used alone or in combination. Further, even a solvent that does not dissolve the polyamic acid may be used by mixing with the above solvent as long as the produced polyamic acid does not precipitate.
In addition, since water in the organic solvent inhibits the polymerization reaction and further causes hydrolysis of the produced polyamic acid, it is preferable to use a dehydrated and dried organic solvent as much as possible.

When the tetracarboxylic 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 dianhydride component is used as it is or in an 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 dianhydride component is dispersed or dissolved in an organic solvent, and a tetracarboxylic dianhydride component and a diamine component. The method of adding alternately etc. is mentioned, Any method may be used. In addition, 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 reacted sequentially, or may be further reacted individually. The body may be mixed and reacted to form a high molecular weight body.
Although the polymerization temperature in that case can select arbitrary temperature of -20-150 degreeC, Preferably it is the range of -5-100 degreeC.

The reaction can be carried out at any concentration, but if the concentration is too low, it is 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 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 is performed at a high concentration, and then an organic solvent can be added.
In the polyamic acid polymerization reaction, the ratio of the total number of moles of tetracarboxylic dianhydride to the total number of moles of the diamine component is preferably 0.8 to 1.2. Similar to the normal polycondensation reaction, the closer the molar ratio is to 1.0, the higher the molecular weight of the polyamic acid produced.
The molecular weight of the polyamic acid contained in the liquid crystal aligning agent of the present invention is GPC (Gel Permeation Chromatography) in consideration of the strength of the coating film obtained therefrom, workability when forming the coating film, uniformity of the coating film, and the like. The weight average molecular weight measured by the method 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 this invention is a coating liquid for forming a liquid crystal aligning film, and is a solution which the resin component for forming a resin film melt | dissolved in the organic solvent. Here, the resin component is a resin component containing the above-described polyamic acid. At that time, the content of the resin component in the coating solution is preferably 1 to 20% by mass, more preferably 3 to 15% by mass, and particularly preferably 3 to 10% by mass.

In the liquid crystal aligning agent of the present invention, all of the resin components may be polyamic acid, and other polymers may be mixed with the polyamic acid. In that case, content of polymers other than a polyamic acid in a resin component is 0.5-15 mass%, Preferably it is 1-10 mass%.
Examples of the other polymer include polyamic acid 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 this invention will not be specifically limited if it is an organic solvent in which a resin component is dissolved. 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, 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 and the like.
These may be used alone or in combination.
Content of the organic solvent used for the liquid crystal aligning agent of this invention is 80-99 mass% with respect to the coating liquid (liquid crystal aligning agent) whole (100 mass%), Preferably it is 85-99 mass%.

The liquid crystal aligning agent of this invention may contain components other than the above. Examples thereof include solvents and compounds that improve the film thickness uniformity and surface smoothness when a liquid crystal aligning agent is applied, and compounds that improve the adhesion between the liquid crystal aligning film and the substrate.
The following are mentioned as a specific example of the solvent (poor solvent) which improves the uniformity of film thickness and surface smoothness.
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, dipro Lenglycol 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, 1-hexanol, n-hexane, n-pentane, n-octane Diethyl ether, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, 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, 1-phenoxy-2-propanol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol- Low surface such as monoethyl ether-2-acetate, dipropylene glycol, 2- (2-ethoxypropoxy) propanol, lactate methyl ester, lactate ethyl ester, lactate n-propyl ester, lactate n-butyl ester, lactate isoamyl ester Examples thereof include a solvent having tension.
These poor solvents may be used alone or in combination. When using the above solvent, it is preferable that it is 5-80 mass% of the whole solvent contained in a liquid crystal aligning agent, More preferably, it is 20-60 mass%.

Examples of compounds that improve film thickness uniformity and surface smoothness include fluorine-based surfactants, silicone-based surfactants, and nonionic surfactants.
More specifically, for example, F-top EF301, EF303, EF352 (manufactured by Tochem Products), MegaFuck F171, F173, R-30 (manufactured by Dainippon Ink), Florard 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 with respect 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 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-tri Toxisilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyltrimethoxy Silane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3-aminopropyl Trimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, poly Lopylene 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-tetraglycidyl -2,4-hexanediol, N, N, N ′, N ′,-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ′ , N ′,-tetraglycidyl-4,4′-diaminodiphenylmethane and the like.
When using the compound which improves adhesiveness with a board | substrate, it is preferable that the usage-amount is 0.1-30 mass parts with respect to 100 mass parts of the resin component contained in a liquid crystal aligning agent, More preferably. Is 1-20 parts by mass. If the amount used is less than 0.1 parts by mass, the effect of improving the adhesion 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 has a dielectric or conductive material for the purpose of changing the electrical properties such as the dielectric constant and conductivity of the liquid crystal aligning film, as long as the effects of the present invention are not impaired. Further, a crosslinkable compound may be added for the purpose of increasing the hardness and density of the liquid crystal alignment film.

<Liquid crystal alignment film>
The liquid crystal aligning agent of this invention can be used as a liquid crystal aligning film by apply | coating on a board | substrate and baking, and performing alignment processes, such as a rubbing process and light irradiation. In this case, the substrate to be used is not particularly limited as long as it is a highly transparent substrate, and a glass substrate or a plastic substrate such as an acrylic substrate or a polycarbonate substrate can be used. In addition, it is preferable to use a substrate on which an ITO electrode or the like for driving liquid crystal is formed from the viewpoint of simplifying the process. In the reflection type liquid crystal display element, an opaque material such as a silicon wafer can be used as long as only one substrate is used. In this case, a material that reflects light such as aluminum can be used as the electrode.

The method for applying the liquid crystal aligning agent is not particularly limited, but industrially methods such as screen printing, offset printing, flexographic printing, and ink jet are common. Other coating methods include dip, roll coater, slit coater, spinner and the like, and these may be used depending on the purpose.
Firing after applying the liquid crystal aligning agent on the substrate can be 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 be lowered, preferably 5 to 300 nm, more preferably. Is 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 rays.

<Liquid crystal display element>
The liquid crystal display element of the present invention is a liquid crystal display element 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 give an example of liquid crystal cell production, prepare a pair of substrates on which a liquid crystal alignment film is formed, spray spacers on the liquid crystal alignment film of one substrate, and make the liquid crystal alignment film surface inside. Examples include a method of bonding the other substrate and injecting liquid crystal under reduced pressure, or a method in which a liquid crystal is dropped on the liquid crystal alignment film surface on which spacers are dispersed, and then the substrate is bonded to perform sealing. . The thickness of the spacer at this time is preferably 1 to 30 μm, more preferably 2 to 10 μm.
As described above, the liquid crystal display device manufactured using the liquid crystal aligning agent of the present invention has excellent voltage holding characteristics and liquid crystal alignment properties, and can be suitably used for a large-screen, high-definition liquid crystal television. .

  EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples. However, the interpretation of the present invention is not limited to these examples.

The abbreviations of the compounds used in this example are as follows.
(Tetracarboxylic dianhydride)
CBDA: 1,2,3,4-cyclobutanetetracarboxylic dianhydride PMDA: pyromellitic dianhydride (diamine)
3AMPDA: 3,5-diamino-N- (pyridin-3-ylmethyl) benzamine 3APIDA: N- (3- (1H-imidazol-1-yl) propyl-3,5-diaminobenzamide DA-5MG: 1,5- Bis (4-aminophenoxy) pentane DA-3MG: 1,3-bis (4-aminophenoxy) propane DA-2MG: 1,2-bis (4-aminophenoxy) ethane APC18: 1,3-diamino-4- Octadecyloxybenzene APC16: 1,3-diamino-4-hexadecyloxybenzene p-PDA: p-phenylenediamine DDM: diaminodiphenylmethane (organic solvent)
NMP: N-methyl-2-pyrrolidone BCS: Butyl cellosolve γ-BL: γ-butyllactone

Example 1
As a tetracarboxylic dianhydride component, 4.56 g (23.28 mmol) of CBDA, as a diamine component, 1.74 g (7.19 mmol) of 3AMPDA, 3.77 g (13.17 mmol) of DA-5MG, and APC18 1.35 g (3.58 mmol) was weighed and reacted in 83.76 g of NMP at room temperature for 3 hours to obtain a polyamic acid solution (PAA-1). This polyamic acid had a number average molecular weight of 13,725 and a weight average molecular weight of 32,368.
Next, 45.74 g of polyamic acid solution (PAA-1) was diluted with 22.93 g of NMP and 17.17 g of BC and mixed to obtain a solid content of 6% by mass, NMP of 26% by mass, and BC of 20% by mass. A liquid crystal aligning agent (L-1) was prepared.

(Example 2)
As a tetracarboxylic dianhydride component, 4.74 g (24.17 mmol) of CBDA, as a diamine component, 1.82 g (7.50 mmol) of 3AMPDA, 3.55 g (12.40 mmol) of DA-3MG, and APC18 1.41 g (3.75 mmol) was weighed and reacted in NMP84.24 g at room temperature for 3 hours to obtain a polyamic acid solution (PAA-2). This polyamic acid had a number average molecular weight of 12,889 and a weight average molecular weight of 32,973.
Next, 33.37 g of polyamic acid solution (PAA-2) was diluted with 9.72 g of NMP and 10.77 g of BC and mixed to obtain a solid content of 7% by mass, NMP of 18% by mass, and BC of 20% by mass. A liquid crystal aligning agent (L-2) was prepared.

(Example 3)
As a tetracarboxylic dianhydride component, 5.11 g (26.05 mmol) of CBDA, 1.96 g (8.09 mmol) of 3AMPDA, 4.63 g (16.17 mmol) of DA-5MG, and APC16 as a diamine component 0.94 g (2.70 mmol) was weighed and reacted in 92.18 g of NMP at room temperature for 3 hours to obtain a polyamic acid solution (PAA-3). This polyamic acid had a number average molecular weight of 10,554 and a weight average molecular weight of 27,445.
Next, 49.18 g of polyamic acid solution (PAA-3) was diluted with 26.36 g of NMP and 18.89 g of BC and mixed to obtain a solid content of 6% by mass, NMP of 28% by mass, and BC of 20% by mass. A liquid crystal aligning agent (L-3) was prepared.

Example 4
As a tetracarboxylic dianhydride component, 4.54 g (23.15 mmol) of CBDA, as a diamine component, 1.89 g (7.31 mmol) of 3APIDA, 3.78 g (13.20 mmol) of DA-5MG, and APC18 1.36 g (3.60 mmol) was weighed and reacted in NMP 84.66 g at room temperature for 3 hours to obtain a polyamic acid solution (PAA-4). This polyamic acid had a number average molecular weight of 10,082 and a weight average molecular weight of 21,427.
Next, 49.66 g of polyamic acid solution (PAA-54) was diluted with 25.82 g of NMP and 18.87 g of BC, and mixed to obtain a solid content of 6% by mass, NMP of 27% by mass, and BC of 20% by mass. A liquid crystal aligning agent (L-4) was prepared.

(Example 5)
As a tetracarboxylic dianhydride component, 2.61 g (11.98 mmol) of PMDA, 2.20 g (11.20 mmol) of CBDA, 1.74 g (7.20 mmol) of 3AMPDA as a diamine component, DA-5MG 3.78 g (13.20 mmol) and 1.36 g (3.60 mmol) of APC18 were weighed and reacted in NMP 85.36 g at room temperature for 3 hours to obtain a polyamic acid solution (PAA-5). This polyamic acid had a number average molecular weight of 12,510 and a weight average molecular weight of 28,289.
Next, 23.36 g of polyamic acid solution (PAA-5) was diluted with 12.80 g of NMP and 9.00 g of BC, and a liquid crystal aligning agent having a solid content of 6% by mass, NMP of 28% by mass, and BC of 20% by mass. (L-5) was prepared.

(Example 6)
Weigh CBDA (9.81 g, 0.050 mol), PMDA (10.25 g, 0.047 mol) as tetracarboxylic dianhydride components, and DDM (19.83 g, 0.0060 mol) as diamine components. And reacted in γ-BL 113.00 g and NMP 113.00 g at room temperature for 3 hours to obtain a polyamic acid solution (PAA-6). This polyamic acid had a number average molecular weight of 20,863 and a weight average molecular weight of 57,892.
Next, 198.97 g of polyamic acid solution (PAA-6) was diluted with 204.23 g of γ-BL, 14.63 g of NMP, and 73.74 g of BC, and mixed to obtain a solid content of 6% by mass and γ-BL of 59. A liquid crystal aligning agent (L-6) having a mass%, NMP of 20 mass%, and BC of 15 mass% was prepared.

(Example 7)
The liquid crystal aligning agent (L-1) prepared in Example 1 and the liquid crystal aligning agent (L-6) prepared in Example 6 were mixed so that the weight ratio was 20:80, and then at room temperature for 1 hour. The liquid crystal aligning agent (L-7) was obtained by stirring.

(Example 8)
The liquid crystal aligning agent (L-4) prepared in Example 4 and the liquid crystal aligning agent (L-6) prepared in Example 6 were mixed so that the weight ratio was 20:80, and then at room temperature for 1 hour. The liquid crystal aligning agent (L-8) was obtained by stirring.

(Comparative Example 1)
As the tetracarboxylic dianhydride component, 4.71 g (24.03 mmol) of CBDA, 1.80 g (7.44 mmol) of 3AMPDA, 3.35 g (11.90 mmol) of DA-2MG, and APC18 as the diamine component 1.41 g (3.75 mmol) was weighed and reacted in NMP 82.83 g at room temperature for 3 hours to obtain a polyamic acid solution (PAA-7). This polyamic acid had a number average molecular weight of 10,961 and a weight average molecular weight of 24,492.
Next, 30.38 g of polyamic acid solution (PAA-7) was diluted with 15.80 g of NMP and 11.54 g of BC and mixed to obtain a solid content of 6% by mass, NMP of 27% by mass, and BC of 20% by mass. A liquid crystal aligning agent (L-9) was prepared.

(Comparative Example 2)
As a tetracarboxylic dianhydride component, PMDA is 5.03 g (23.08 mmol), and as a diamine component, 3AMPDA is 1.74 g (7.20 mmol), DA-5MG is 3.78 g (13.20 mmol), and APC18. 1.36 g (3.60 mmol) was weighed and reacted in NMP 83.76 g at room temperature for 3 hours to obtain a polyamic acid solution (PAA-8). This polyamic acid had a number average molecular weight of 12,020 and a weight average molecular weight of 26,924.
Next, 19.65 g of polyamic acid solution (PAA-8) was diluted with 9.95 g of NMP and 7.40 g of BC and mixed to obtain a solid content of 6% by mass, NMP of 27% by mass, and BC of 20% by mass. A liquid crystal aligning agent (L-10) was prepared.

(Comparative Example 3)
Weighing 5.45 g (27.79 mmol) of CBDA as a tetracarboxylic dianhydride component, 2.92 g (27.01 mmol) of p-PDA and 1.05 g (3.01 mmol) of APC16 as a diamine component. Then, the reaction was conducted in 84.91 g of NMP at room temperature for 3 hours to obtain a polyamic acid solution (PAA-9). This polyamic acid had a number average molecular weight of 16,868 and a weight average molecular weight of 45,436.
Next, 39.85 g of polyamic acid solution (PAA-9) was diluted with 12.34 g of NMP and 14.01 g of BC and mixed to obtain a solid content of 6% by mass, NMP of 74% by mass, and BC of 20% by mass. A liquid crystal aligning agent (L-11) was prepared.

<Measurement of molecular weight>
The molecular weight of the polyamic acid obtained by the polymerization reaction was measured by a GPC (room temperature gel permeation chromatography) apparatus. That is, the number average molecular weight and the weight average molecular weight were calculated as polyethylene glycol and polyethylene oxide equivalent values.
GPC device: manufactured by Shodex (GPC-101)
Column: manufactured by Shodex (series of KD803 and KD805)
Column temperature: 50 ° C
Eluent: N, N-dimethylformamide (as an additive, lithium bromide-hydrate (LiBr · H ₂ O)) 30 mmol / L (liter), phosphoric acid / anhydrous crystal (o-phosphoric acid) 30 mmol / L, tetrahydrofuran (THF) 10ml / L)
Flow rate: 1.0 ml / min Standard sample for preparation of calibration curve: TSK standard polyethylene oxide (molecular weight: about 900,000, 150,000, 100,000, and 30,000) manufactured by Tosoh Corporation, and polyethylene glycol (molecular weight: about 12,000, 4,000, molecular weight manufactured by Polymer Laboratory) And 1,000).

<Production of liquid crystal cell>
About the liquid crystal aligning agent prepared in Examples 1-5, 7, 8, and Comparative Examples 1-3, the liquid crystal cell was produced as follows.
A liquid crystal aligning agent is spin-coated on a glass substrate with a transparent electrode, dried on a hot plate at 70 ° C. for 70 seconds, and then baked on a hot plate at 210 ° C. for 10 minutes to form a coating film having a thickness of 100 nm. It was. The coating surface was rubbed with a rubbing apparatus having a roll diameter of 120 mm using a rayon cloth under the conditions of a roll rotation speed of 1000 rpm, a roll traveling speed of 50 mm / sec, and an indentation amount of 0.3 mm to obtain a substrate with a liquid crystal alignment film. . Next, two substrates with a liquid crystal alignment film are prepared, and a spacer of 6 μm is sprayed on the surface of one liquid crystal alignment film, and then a sealing agent is printed thereon, and another substrate is mounted on the liquid crystal alignment film surface. Were stuck together so that the rubbing direction was orthogonal, and then the sealing agent was cured to produce an empty cell. Liquid crystal MLC-2003 (Merck Japan Co., Ltd.) was injected into this empty cell by a reduced pressure injection method, and the injection port was sealed to obtain a twisted nematic liquid crystal cell.

Evaluation of the orientation of the liquid crystal alignment film formed using each liquid crystal aligning agent, and measurement evaluation of the voltage holding ratio of the liquid crystal cell having the liquid crystal alignment film were performed as follows.
<Orientation evaluation>
As an orientation verification test, the sample was rubbed under the condition that the roll rotation speed was 300 rpm and the amount of pushing was changed to 0.15 mm, and observed visually. Evaluation was performed as follows.
A: No flow is observed.
○: Flow is slightly observed.
X: 10 or more flows are observed.

<Measurement of voltage holding ratio (VHR)>
The voltage holding ratio of the manufactured twisted nematic liquid crystal cell is measured by applying a voltage of 4 V for 60 μs at a temperature of 90 ° C., measuring the voltage after 166.7 ms, and determining how much the voltage can be held. As calculated. For measuring the voltage holding ratio, a VHR-1 voltage holding ratio measuring device manufactured by Toyo Corporation was used.
In Table 4, the liquid crystal aligning agent obtained in Examples 1-5, 7, 8, and Comparative Examples 1-3, the evaluation result of the orientation of the liquid crystal aligning film produced using this liquid crystal aligning agent, and this The measurement results of the voltage holding ratio of the twisted nematic liquid crystal cell having the liquid crystal alignment film are collectively shown.
As can be seen from Table 4, the liquid crystal cell obtained using the liquid crystal aligning agent of the present invention has good liquid crystal alignment and voltage holding ratio characteristics. On the other hand, in the diamine of the formula (2), Comparative Example 1 using a diamine in which n is 2 has a good voltage holding property but a poor liquid crystal alignment property. In Comparative Example 2 using an aromatic acid dihydrate, the liquid crystal alignment characteristics were good, but the voltage holding ratio characteristics were extremely poor. In Comparative Example 3 in which neither the diamine corresponding to the formula (1) nor the diamine corresponding to the formula (2) was used, both characteristics were bad.

The liquid crystal display element produced using the liquid crystal aligning agent containing the polyamic acid of the present invention is excellent in voltage holding characteristics and liquid crystal orientation, and can be suitably used for a large-screen, high-definition liquid crystal television. Is possible.
The entire contents of the specification, claims, and abstract of Japanese Patent Application No. 2012-008264 filed on January 18, 2012 are incorporated herein as the disclosure of the specification of the present invention. Is.

Claims (12)

A diamine component containing a diamine compound of the following formulas (1) and (2) is reacted with a tetracarboxylic dianhydride component containing a tetracarboxylic dianhydride having an alicyclic structure or an aliphatic structure. Liquid crystal aligning agent containing the polyamic acid obtained.

(In the formula (1), X ₁ is ^{-O -, - NQ 1 -,} - CONQ 1 -, - NQ 1 CO -, - CH 2 O-, and at least one selected from the group consisting of -OCO- A divalent organic group, Q ¹ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, X ₂ is a single bond, an aliphatic hydrocarbon group having 1 to 20 carbon atoms, or a non-aromatic cyclic carbonization hydrogen radicals, and at least one divalent organic group selected from the group consisting of an aromatic hydrocarbon radical .X ₃ is a single bond or ^{-O -, - NQ 2 -,} - CONQ 2 -, - NQ ² CO—, —COO—, —OCO—, and —O (CH ₂ ) _m — (m is an integer of 1 to 5), and at least one divalent organic group selected from the group consisting of Q ² is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, X ₄ is a nitrogen-containing aromatic heterocyclic group, n Is an integer from 1 to 4.
N in Formula (2) is an integer of 3-10. )   The liquid crystal aligning agent according to claim 1, wherein the polyamic acid has a weight average molecular weight of 5,000 to 1,000,000. _{X 1} in the formula (1) is ^{-O -, - NQ 1 -,} - CONQ 1 -, and at least one selected from the group consisting of ^-NQ 1 CO-, _{X 2} is a single bond, one carbon atom to 3 straight chain alkylene group, and at least one selected from the group consisting of benzene ring, _{X 3} is a single bond, -OCO-, and -OCH ₂ - is at least one selected from the group consisting of, X ₄ is an imidazole ring, at least one selected from the group consisting of pyridine ring, and a pyrimidine ring, n is an integer of 1 or 2, the liquid crystal alignment agent according to claim 1 or 2.   The liquid crystal aligning agent in any one of Claims 1-3 whose diamine of Formula (1) is 5-50 mol% in all the diamine components. X ₄ in the formula (1) is a liquid crystal aligning agent according to claim 1 which is pyridine ring or imidazole ring.   The liquid crystal aligning agent in any one of Claims 1-5 whose diamine of Formula (2) is 10-50 mol% in all the diamine components.   N in Formula (2) is 3-8, The liquid crystal aligning agent in any one of Claims 1-6.   The liquid crystal aligning agent in any one of Claims 1-7 in which the said tetracarboxylic dianhydride component further contains aromatic tetracarboxylic dianhydride.   The liquid crystal aligning film obtained using the liquid crystal aligning agent in any one of Claims 1-8.   The liquid crystal aligning film of Claim 9 in which the said liquid crystal aligning agent contains 80-99 mass% organic solvent with respect to the whole liquid crystal aligning agent (100 mass%).   The organic solvent is N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 2-pyrrolidone, N-ethylpyrrolidone, N-vinylpyrrolidone, dimethyl sulfoxide, tetra Methyl urea, pyridine, dimethyl sulfone, hexamethyl sulfoxide, γ-butyrolactone, 1,3-dimethyl-imidazolidinone, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, cyclohexanone, ethylene carbonate, propylene The liquid crystal alignment film according to claim 10, which is at least one selected from the group consisting of carbonate, diglyme, and 4-hydroxy-4-methyl-2-pentanone. The liquid crystal display element which comprises the liquid crystal aligning film in any one of Claims 9-11.