JP6555257B2 - Liquid crystal aligning agent, liquid crystal aligning 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.

  A liquid crystal display element used in a liquid crystal television, a liquid crystal display, or the like is usually provided with a liquid crystal alignment film for controlling the alignment state of liquid crystals. As the liquid crystal alignment film, a polyimide liquid crystal alignment film obtained by applying a polyimide precursor such as polyamic acid (also referred to as polyamic acid) or a liquid crystal aligning agent having a soluble polyimide solution as a main component to a glass substrate and baking it is used. Mainly used (see Patent Documents 1 and 2).

Japanese Unexamined Patent Publication No. 9-316200 Japanese Unexamined Patent Publication No. 10-104633

Currently, liquid crystal alignment films used in liquid crystal display elements of IPS (In Plane Switching) and FFS (fringe field switching) driving methods are IPS driven in addition to basic characteristics such as excellent liquid crystal alignment and electrical characteristics. It is necessary to simultaneously satisfy various characteristics such as suppression of afterimages caused by long-term alternating current driving that occurs in liquid crystal display elements of the system and FFS driving system.
An object of the present invention is to provide a liquid crystal aligning agent capable of forming a liquid crystal alignment film used in a liquid crystal display element having excellent liquid crystal alignment properties and electrical characteristics and capable of suppressing afterimages by long-term alternating current driving, and the liquid crystal alignment It is providing the liquid crystal aligning film obtained from an agent, and the liquid crystal display element which comprises this liquid crystal aligning film.

  As a result of diligent research, the present inventors have met the above-mentioned various problems simultaneously and at a high level when using a liquid crystal aligning agent containing a polymer obtained by using a specific diamine. The present invention has been found. The present invention has the following features.

（Ａ^１及びＡ^５は、それぞれ独立して、単結合、又は炭素数１〜５のアルキレン基であり、Ａ^２及びＡ^４は、それぞれ独立して、炭素数１〜５のアルキレン基であり、Ａ^３は炭素数１〜６のアルキレン基、又はシクロアルキレン基であり、Ｂ^１及びＢ^２は、それぞれ独立して、単結合、−Ｏ−、 −ＮＨ−、 −ＮＭｅ−、 −Ｃ（＝Ｏ）−、−Ｃ(＝Ｏ)Ｏ−、 −Ｃ(＝Ｏ)ＮＨ−、 −Ｃ(＝Ｏ)ＮＭｅ−、 −ＯＣ(＝Ｏ)−、 −ＮＨＣ(＝Ｏ)−、又は−Ｎ(Ｍｅ)Ｃ(＝Ｏ)−であり、Ｄ_１はｔｅｒｔ−ブトキシカルボニル基、又は９−フルオレニルメトキシカルボニル基であり、ａは０又は１である。）

（Ｒ_１、Ｒ_２、Ｒ_３及びＲ_４は、それぞれ独立して、水素原子、ハロゲン原子、炭素数１〜６のアルキル基、炭素数２〜６のアルケニル基、炭素数２〜６のアルキニル基、又はフェニル基である。）

（Ｒ_５は水素原子、又は１価の有機基を表す。Ｑ１は、炭素数１〜５のアルキレン基を表し、Ｃｙはアゼチジン、ピロリジン、ピペリジン、又はヘキサメチレンイミン骨格を有する脂肪族へテロ環である２価の基であり、これらの環部分には置換基が結合されていてもよい。Ｒ_６及びＲ_７は、それぞれ独立して、１価の有機基であり、ｑ及びｒは、それぞれ独立して、０〜４の整数である。但し、ｑとｒの合計が２以上の場合、複数のＲ_６及びＲ_７は、それぞれ独立して、上記定義を有する。）1. Liquid crystal aligning agent containing the following (A) component and (B) component.
(A) Component: Polyamic acid ester obtained by reacting a diamine component containing a diamine having the structure of the following formula [1] with a tetracarboxylic acid diester component having the structure of the following formula [2].
(B) Component: Polyamic acid obtained by reacting a diamine component containing a diamine represented by the following formula [3] with a tetracarboxylic dianhydride component containing an aromatic tetracarboxylic dianhydride.

(A ¹ and A ⁵ are each independently a single bond or an alkylene group having 1 to 5 carbon atoms, and A ² and A ⁴ are each independently an alkylene group having 1 to 5 carbon atoms. , A ³ is an alkylene group having 1 to 6 carbon atoms or a cycloalkylene group, and B ¹ and B ² are each independently a single bond, —O—, —NH—, —NMe—, —C ( = O)-, -C (= O) O-, -C (= O) NH-, -C (= O) NMe-, -OC (= O)-, -NHC (= O)-, or- N (Me) C (═O) —, D ₁ is a tert-butoxycarbonyl group, or a 9-fluorenylmethoxycarbonyl group, and a is 0 or 1.)

(R ₁ , R ₂ , R ₃ and R ₄ 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, or an alkynyl group having 2 to 6 carbon atoms. Group or phenyl group.)

(R ₅ represents a hydrogen atom or a monovalent organic group. Q 1 represents an alkylene group having 1 to 5 carbon atoms, and Cy represents an aliphatic heterocyclic ring having an azetidine, pyrrolidine, piperidine, or hexamethyleneimine skeleton. A substituent may be bonded to these ring portions, R ₆ and R ₇ are each independently a monovalent organic group, q and r are And each independently represents an integer of 0 to 4. However, when the sum of q and r is 2 or more, a plurality of R ₆ and R ₇ each independently have the above definition.)

ｎは、１〜３の整数である。
３．上記式[１]の構造を有するジアミンが、（Ａ）成分で用いられる全ジアミン成分の１〜６０モル％である、上記１又は２に記載の液晶配向剤。
４．上記式[３]で表されるジアミンが、（Ｂ）成分で用いられる全ジアミン成分の１〜６０モル％である、上記１〜３のいずれかに記載の液晶配向剤。
５．（Ａ）成分と（Ｂ）成分とを、１０：９０〜９０：１０の質量比で含有する、上記１〜４のいずれかに記載の液晶配向剤。
６．上記１〜５のいずれかに記載の液晶配向剤から得られる液晶配向膜。
７．上記６に記載の液晶配向膜を具備する液晶表示素子。2. The liquid crystal aligning agent of said 1 whose (A) component and (B) component further contain the diamine which has a structure of following formula [4] in a diamine component.

n is an integer of 1 to 3.
3. The liquid crystal aligning agent of said 1 or 2 whose diamine which has the structure of said Formula [1] is 1-60 mol% of all the diamine components used by (A) component.
4). The liquid crystal aligning agent in any one of said 1-3 whose diamine represented by the said Formula [3] is 1-60 mol% of all the diamine components used by (B) component.
5). The liquid crystal aligning agent in any one of said 1-4 containing (A) component and (B) component by mass ratio of 10: 90-90: 10.
6). The liquid crystal aligning film obtained from the liquid crystal aligning agent in any one of said 1-5.
7). 7. A liquid crystal display device comprising the liquid crystal alignment film as described in 6 above.

  According to the liquid crystal aligning agent of the present invention, in addition to basic characteristics such as excellent liquid crystal alignment and electrical characteristics, it is used in liquid crystal display elements of an IPS driving method and an FFS driving method, such as suppression of afterimages by long-term AC driving. A liquid crystal alignment film satisfying various characteristics can be formed.

The liquid crystal aligning agent of this invention is a liquid crystal aligning agent containing the following (A) component and (B) component.
<(A) component>
Component (A) is a polyamic acid ester (polyamic acid ester) obtained by reacting a diamine component containing a diamine having the structure of the following formula [1] with a tetracarboxylic acid diester component having the structure of the following formula [2]. ).

A ¹ and A ⁵ are each independently a single bond or an alkylene group having 1 to 5 carbon atoms, and a single bond or a methylene group is preferable from the viewpoint of reactivity with a functional group in the sealant.
A ² and A ⁴ are each independently an alkylene group having 1 to 5 carbon atoms, preferably a methylene group or an ethylene group.
A ³ is an alkylene group having 1 to 6 carbon atoms or a cycloalkylene group, and a methylene group or an ethylene group is preferable from the viewpoint of reactivity with a functional group in the sealant.

B ¹ and B ² are each independently a single bond, —O—, —NH—, —NMe—, —C (═O) —, —C (═O) O—, —C (═O) NH—, —C (═O) NMe—, —OC (═O) —, —NHC (═O) —, or —N (Me) C (═O) —, and the liquid crystal of the obtained liquid crystal alignment film From the viewpoint of orientation, a single bond or —O— is preferable.
D ₁ is a tert-butoxycarbonyl group or a 9-fluorenylmethoxycarbonyl group, and a tert-butoxycarbonyl group is preferred from the viewpoint of deprotection temperature.
a is 0 or 1;
Specific examples of the diamine represented by the above formula [1] include the following formulas (1-1) to (1-21).

In formulas (1-1) to (1-21), Me represents a methyl group, and D ₂ represents a tert-butoxycarbonyl group.
Among these, formulas (1-1) to (1-4) are more preferable, and formula (1-2) is particularly preferable.

Ｒ_１、Ｒ_２、Ｒ_３及びＲ_４は、それぞれ独立して、水素原子、ハロゲン原子、炭素数１〜６のアルキル基、炭素数２〜６のアルケニル基、炭素数２〜６のアルキニル基、又はフェニル基である。その中でも、ラビング耐性の観点から、水素原子であることが好ましい。
上記式[１]の構造を有するジアミンは、（Ａ）成分の重合に用いる全ジアミン成分の１〜６０モル％であることが好ましく、５〜４０モル％がさらに好ましい。

R ₁ , R ₂ , R ₃ and R ₄ 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, or an alkynyl group having 2 to 6 carbon atoms. Or a phenyl group. Among these, a hydrogen atom is preferable from the viewpoint of rubbing resistance.
The diamine having the structure of the above formula [1] is preferably 1 to 60 mol%, more preferably 5 to 40 mol%, based on the total diamine components used for the polymerization of the component (A).

ｎは、１〜３の整数である。
式[４]の構造を有するジアミンは、（Ａ）成分の重合に用いる全ジアミン成分の１〜９０モル％であることが好ましく、２０〜９０モル％がさらに好ましい。As the second diamine used for the component (A), a diamine having the structure of the following formula [4] is preferably used from the viewpoint of liquid crystal alignment.

n is an integer of 1 to 3.
The diamine having the structure of the formula [4] is preferably 1 to 90 mol%, more preferably 20 to 90 mol%, based on the total diamine components used for the polymerization of the component (A).

Ｙとしては、以下の構造が例示されるが、これに限定されるものではない。The other diamine used for the component (A) is represented by the following formula [5].

Examples of Y include the following structures, but are not limited thereto.

なかでも、液晶配向性とラビング耐性の観点から、ＹがＹ−４、Ｙ−６５、Ｙ−６６、Ｙ−６７又はＹ−８３の構造を有するジアミンがより好ましい。

Among these, from the viewpoint of liquid crystal alignment and rubbing resistance, a diamine having a Y structure of Y-4, Y-65, Y-66, Y-67 or Y-83 is more preferable.

Ｒ_５及びＲ_６は、それぞれ独立して、炭素数１〜５のアルキル基であり、好ましくは炭素数１〜２のアルキル基、さらに好ましくはメチル基である。The general formula of the tetracarboxylic acid diester is represented by the following formula (18), and the tetracarboxylic acid diester in which the structure of X _{1 is} the structure of the above formula [2] is used as the component (A) of the liquid crystal aligning agent of the present invention. It is done.

R ₅ and R ₆ are each independently an alkyl group having 1 to 5 carbon atoms, preferably an alkyl group having 1 to 2 carbon atoms, and more preferably a methyl group.

<(B) component>
The component (B) is a polyamic acid obtained by reacting a diamine component containing a diamine represented by the following formula [3] with a tetracarboxylic dianhydride component containing an aromatic tetracarboxylic dianhydride. is there.

R ₅ represents a hydrogen atom or a monovalent organic group, preferably a hydrogen atom or a linear alkyl group having 1 to 3 carbon atoms, more preferably a hydrogen atom or a methyl group. R ₅ may be a protective group that can be replaced by a hydrogen atom by a heat elimination reaction. From the viewpoint of the storage stability of the liquid crystal aligning agent, R ₅ does not desorb at room temperature, preferably at a temperature of 80 ° C. or higher. It is a protecting group that is eliminated, and more preferably a protecting group that is eliminated by heat at 100 ° C. or higher. Examples include a 1,1-dimethyl-2-chloroethoxycarbonyl group, a 1,1-dimethyl-2-cyanoethoxycarbonyl group, a tert-butoxycarbonyl group, and the like, and a tert-butoxycarbonyl group is preferable.

Q ₁ represents an alkylene group having 1 to 5 carbon atoms, and is preferably a linear alkylene group having 1 to 5 carbon atoms from the viewpoint of ease of synthesis.
Cy is a divalent group that is an aliphatic heterocyclic ring having an azetidine, pyrrolidine, piperidine, or hexamethyleneimine skeleton, and azetidine, pyrrolidine, or piperidine is preferable from the viewpoint of ease of synthesis. In addition, a substituent may be bonded to these ring portions.

R ₆ and R ₇ are each independently a monovalent organic group.
q and r are each independently an integer of 0 to 4. However, when the sum of q and r is 2 or more, the plurality of R ₆ and R ₇ each independently have the above definition.
R ₆ and R ₇ are preferably a methyl group for the convenience of synthesis.
In addition, although the bonding position of the amino group in the benzene ring constituting the diamine is not limited, the amino group is the 3rd or 4th position with respect to the nitrogen atom on Cy, and the nitrogen atom to which Q ₁ and R ₅ are bonded. In contrast, it is preferably in the 3rd or 4th position, more preferably in the 4th position with respect to the nitrogen atom on Cy and in the 4th position with respect to the nitrogen atom to which Q ₁ and R ₅ are bonded. preferable.

Ｒ_８は、水素原子、メチル基、又はｔｅｒｔ−ブトキシカルボニル基である。Ｒ_９は、水素原子又はメチル基である。Ｑ_１は、炭素数１〜５の直鎖アルキレン基である。The diamine represented by the above formula [3] of the present invention is preferably the following formula (6).

R ₈ is a hydrogen atom, a methyl group, or a tert-butoxycarbonyl group. R ₉ is a hydrogen atom or a methyl group. Q ₁ is a linear alkylene group having 1 to 5 carbon atoms.

式（３）で表されるジアミンを製造する方法は特に限定されないが、好ましい方法としては、日本特願２０１４−０２５４３８に記載の通りである。
上記式[３]の構造を有するジアミンは、（Ｂ）成分の重合に用いる全ジアミン成分の１〜６０モル％であることが好ましく、５〜４０モル％がさらに好ましい。Specific examples of the diamine represented by the above formula (6) include the following formulas (6-1) to (6-10). In the following formula, Boc represents a tert-butoxycarbonyl group.

The method for producing the diamine represented by the formula (3) is not particularly limited, but a preferred method is as described in Japanese Patent Application No. 2014-025438.
The diamine having the structure of the above formula [3] is preferably 1 to 60 mol%, more preferably 5 to 40 mol%, based on the total diamine components used for the polymerization of the component (B).

The other diamine used for the component (B) is represented by the above formula [5], and the specific structure of Y is as exemplified above, but is not limited thereto.
In particular, in order to obtain a liquid crystal alignment film in which the residual charges accumulated in the liquid crystal display element by the direct current voltage can be relaxed faster, Y is Y-68, Y-69, Y-70, Y-71, Y-72. Y-73, Y-74, Y-75, Y-76, Y-77, Y-78, Y-79, Y-80, Y-81, Y-82, or the structure of the above formula [4] The diamine it has is preferred.
The diamine having the structure of the above formula [4] or [5] is preferably 1 to 90 mol%, more preferably 5 to 70 mol% of the total diamine component used for the polymerization of the component (B).

The tetracarboxylic dianhydride component used for the component (B) contains an aromatic tetracarboxylic dianhydride. The aromatic tetracarboxylic dianhydride refers to a tetracarboxylic dianhydride in which an acid anhydride structure and an aromatic ring are directly bonded.
The general formula of tetracarboxylic dianhydride is represented by the following formula (17).

Examples of the structure of X include the following structures, but are not limited thereto.

上記に例示した構造のうち、芳香族系酸二無水物は、Ｘの構造が、Ｘ−２６〜Ｘ−４１のものを指す。
直流電圧により液晶表示素子内に蓄積した残留電荷の緩和がより早い液晶配向膜を得るためには、(Ｂ)成分に用いられるテトラカルボン酸二無水物成分中、芳香族系テトラカルボン酸二無水物は２０〜１００モル％が好ましく、５０〜１００モル％がより好ましい。

Among the structures exemplified above, the aromatic acid dianhydride indicates that the structure of X is X-26 to X-41.
In order to obtain a liquid crystal alignment film in which the residual charge accumulated in the liquid crystal display element by DC voltage is more quickly relaxed, among the tetracarboxylic dianhydride components used for the component (B), aromatic tetracarboxylic dianhydride The product is preferably 20 to 100 mol%, more preferably 50 to 100 mol%.

<Production of polyamic acid>
The polyamic acid contained in the liquid crystal aligning agent of the present invention comprises a tetracarboxylic dianhydride component and a diamine component in the presence of an organic solvent at −20 to 150 ° C., preferably 0 to 50 ° C., 30 It is produced by a polycondensation reaction for min to 24 hours, preferably 1 to 12 hours.

Reaction of a diamine component and a tetracarboxylic dianhydride component is normally performed in an organic solvent. The organic solvent used at that time is not particularly limited as long as the produced polyamic acid is soluble. Although the specific example of the organic solvent used for reaction is given, it is not limited to these examples.
Examples include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide or 1,3-dimethyl-imidazolidinone. It is done. When the solvent solubility of the polyamic acid is high, it is represented by methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, or the following formula [D-1] to formula [D-3]. An organic solvent can be used.

式［Ｄ−１］中、Ｄ^１は炭素数１〜３のアルキル基を示し、式［Ｄ−２］中、Ｄ^２は炭素数１〜３のアルキル基を示し、式［Ｄ−３］中、Ｄ^３は炭素数１〜４のアルキル基を示す。

In the formula [D-1], D ¹ represents an alkyl group having 1 to 3 carbon atoms. In the formula [D-2], D ² represents an alkyl group having 1 to 3 carbon atoms. The formula [D-3] Among them, D ³ represents an alkyl group having 1 to 4 carbon atoms.

The organic solvent may be used alone or in combination. Further, even a solvent that does not dissolve the polyimide precursor may be used by mixing with the organic solvent as long as the generated polyimide precursor does not precipitate.
Moreover, since the water | moisture content in an organic solvent inhibits a polymerization reaction, and also causes the produced polyimide precursor to hydrolyze, it is preferable to use what dehydrated and dried the organic solvent.
The concentration of the polyamic acid polymer in the reaction system is preferably 1 to 30% by mass and more preferably 5 to 20% by mass from the viewpoint that polymer precipitation is unlikely to occur and a high molecular weight body is easily obtained.

  The polyamic acid obtained as described above can be recovered by precipitating the polymer (polyamic acid) by pouring into the poor solvent while thoroughly stirring the reaction solution. Moreover, the precipitation of the polyamic acid refined | purified can be obtained by performing precipitation several times, washing | cleaning with a poor solvent, and carrying out normal temperature or heat drying. Although a poor solvent is not specifically limited, Water, methanol, ethanol, hexane, butyl cellosolve, acetone, toluene etc. are mentioned.

<Production of polyamic acid ester>
The polyamic acid ester contained in the liquid crystal aligning agent of this invention can be manufactured with the manufacturing method of (A), (B) or (C) shown below.
(A) In the case of producing from polyamic acid The polyamic acid ester can be produced by esterifying the polyamic acid produced as described above. Specifically, it is produced by reacting a polyamic acid and an esterifying agent in the presence of an organic solvent at −20 to 150 ° C., preferably 0 to 50 ° C., for 30 minutes to 24 hours, preferably 1 to 4 hours. can do.

  As the esterifying agent, those that can be easily removed by purification are preferred, and N, N-dimethylformamide dimethyl acetal, N, N-dimethylformamide diethyl acetal, N, N-dimethylformamide dipropyl acetal, N, N-dimethylformamide Dineopentyl butyl acetal, N, N-dimethylformamide di-t-butyl acetal, 1-methyl-3-p-tolyltriazene, 1-ethyl-3-p-tolyltriazene, 1-propyl-3-p -Tolyltriazene, 4- (4,6-dimethoxy-1,3,5-triazin-2-yl) -4-methylmorpholinium chloride and the like. The addition amount of the esterifying agent is preferably 2 to 6 molar equivalents, more preferably 2 to 4 molar equivalents, per 1 mol of the polyamic acid repeating unit.

  The organic solvent used in the above reaction is preferably N, N-dimethylformamide, N-methyl-2-pyrrolidone, or γ-butyrolactone from the solubility of the polymer (polyamic acid ester), and these are one or more. May be used in combination. The polymer concentration during production is preferably 1 to 30% by mass and more preferably 5 to 20% by mass from the viewpoint that polymer precipitation is unlikely to occur and a high molecular weight body is easily obtained.

(B) When manufacturing by reaction with tetracarboxylic-acid diester dichloride and diamine Polyamic acid ester can be manufactured from tetracarboxylic-acid diester dichloride and diamine.
Specifically, tetracarboxylic acid diester dichloride and diamine are reacted in the presence of a base and an organic solvent at -20 to 150 ° C, preferably at 0 to 50 ° C, for 30 minutes to 24 hours, preferably for 1 to 4 hours. Can be manufactured.

As the base, pyridine, triethylamine, 4-dimethylaminopyridine and the like can be used, but pyridine is preferable because the reaction proceeds gently. The addition amount of the base is preferably 2 to 4 times mol, preferably 2 to 3 times mol with respect to tetracarboxylic acid diester dichloride, in terms of easy removal and high molecular weight. More preferred.
The organic solvent used in the above reaction is preferably N-methyl-2-pyrrolidone or γ-butyrolactone from the solubility of the monomer and polymer (polyamic acid ester), and these may be used alone or in combination. Also good. The polymer concentration during production is preferably 1 to 30% by mass and more preferably 5 to 20% by mass from the viewpoint that polymer precipitation is unlikely to occur and a high molecular weight body is easily obtained.
In order to prevent hydrolysis of the tetracarboxylic acid diester dichloride, the organic solvent to be used is preferably dehydrated as much as possible, and the reaction is preferably prevented from mixing outside air in a nitrogen atmosphere.

(C) When producing from tetracarboxylic acid diester and diamine Polyamic acid ester can be produced by polycondensation of tetracarboxylic acid diester and diamine.
Specifically, tetracarboxylic acid diester and diamine are added in the presence of a condensing agent, a base, and an organic solvent at 0 to 150 ° C., preferably at 0 to 100 ° C., for 30 minutes to 24 hours, preferably 3 to 15 hours. It can manufacture by making it react for time.
Examples of the condensing agent include triphenyl phosphite, dicyclohexylcarbodiimide, 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride, N, N′-carbonyldiimidazole, dimethoxy-1,3,5-triazi Nylmethylmorpholinium, O- (benzotriazol-1-yl) -N, N, N ′, N′-tetramethyluronium tetrafluoroborate, O- (benzotriazol-1-yl) -N, N , N ′, N′-tetramethyluronium hexafluorophosphate, diphenyl (2,3-dihydro-2-thioxo-3-benzoxazolyl) phosphonate, and the like. The addition amount of the condensing agent is preferably 2 to 3 times mol, more preferably 2 to 2.5 times mol based on the tetracarboxylic acid diester.

As the base, tertiary amines such as pyridine and triethylamine can be used. The addition amount of the base is preferably 2 to 4 times mol, more preferably 2 to 3 times mol with respect to the diamine, in terms of easy removal and high molecular weight.
In the above reaction, the reaction proceeds efficiently by adding Lewis acid as an additive. As the Lewis acid, lithium halides such as lithium chloride and lithium bromide are preferable. The addition amount of the Lewis acid is preferably 0 to 1.0 times mol, more preferably 2.0 to 3.0 times mol based on the diamine.

Among the three methods for producing a polyamic acid ester, since a high molecular weight polyamic acid ester is obtained, the production method (A) or (B) is particularly preferred.
The solution of the polyamic acid ester obtained as described above can be precipitated into a poor solvent while being well stirred, so that a polymer (polyamic acid ester) can be precipitated. Precipitation is performed several times, washed with a poor solvent, and then dried at room temperature or by heating to obtain a purified polyamic acid ester powder. Although a poor solvent is not specifically limited, Water, methanol, ethanol, hexane, butyl cellosolve, acetone, toluene etc. are mentioned.

<Liquid crystal aligning agent>
The liquid crystal aligning agent of this invention has the form of the solution in which the polyamic acid ester which is (A) component, and the polyamic acid which is (B) component were melt | dissolved in the organic solvent.
The molecular weight of the specific structure polymer is preferably 2,000 to 500,000 in terms of weight average molecular weight, more preferably 5,000 to 300,000, and still more preferably 10,000 to 100,000. The number average molecular weight is preferably 1,000 to 250,000, more preferably 2,500 to 150,000, and still more preferably 5,000 to 50,000.
The specific structure polymer of the present invention means a polymer such as a polyamic acid ester as the component (A) and a polyamic acid as the component (B).
As for the ratio of the specific polymer (B) in a liquid crystal aligning agent, 10-900 mass parts is preferable with respect to 100 mass parts of specific polymers (A). Especially, 25-700 mass parts is preferable, and 50-500 mass parts is more preferable. Most preferred is 100 to 400 parts by weight.

The organic solvent (hereinafter also referred to as a good solvent) contained in the liquid crystal aligning agent used in the present invention is not particularly limited as long as the specific structure polymer is uniformly dissolved.
For example, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethyl sulfoxide, γ-butyrolactone, 1,3-dimethyl-imidazolidinone, methyl ethyl ketone , Cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, and the like.
Among these, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, or γ-butyrolactone is preferably used.
Furthermore, when the solubility of the specific structure polymer of the present invention in a solvent is high, it is preferable to use a solvent represented by the formula [D-1] to the formula [D-3].
The good solvent in the liquid crystal aligning agent of the present invention is preferably 20 to 99% by mass, more preferably 20 to 90% by mass, and more preferably 30 to 80% by mass with respect to the total solvent contained in the liquid crystal aligning agent. It is particularly preferred.

  As long as the effects of the present invention are not impaired, the liquid crystal aligning agent of the present invention uses a solvent (also referred to as a poor solvent) that improves the coating properties and surface smoothness of the liquid crystal aligning film when the liquid crystal aligning agent is applied. it can. Specific examples of such poor solvents include 1-hexanol, cyclohexanol, 1,2-ethanediol, 1,2-propanediol, propylene glycol monobutyl ether, ethylene glycol monobutyl ether, and dipropylene glycol dimethyl ether. JP2015 / 059476 includes the description, but is not limited to these examples.

  These poor solvents are preferably 1 to 80% by mass, more preferably 10 to 80% by mass, and particularly preferably 20 to 70% by mass of the total solvent contained in the liquid crystal aligning agent.

  In the liquid crystal aligning agent of the present invention, in addition to the above, as long as the effects of the present invention are not impaired, polymers other than the specific structure polymer, electrical properties such as the dielectric constant and conductivity of the liquid crystal aligning film are provided. A dielectric or conductive material for the purpose of changing, a silane coupling agent for the purpose of improving the adhesion between the liquid crystal alignment film and the substrate, a crosslinkable compound for the purpose of increasing the hardness and density of the film when the liquid crystal alignment film is formed, Furthermore, when the coating film is baked, an imidization accelerator for the purpose of efficiently progressing imidization by heating of the polyimide precursor may be added.

<Method for producing liquid crystal alignment film>
The liquid crystal alignment film of the present invention comprises a step of applying a liquid crystal aligning agent to a substrate, drying and baking, a step of irradiating the obtained film with polarized ultraviolet light, a film irradiated with ultraviolet light, water or water and organic It is preferable to manufacture by the manufacturing method including the process of carrying out contact processing with the mixed solvent with a solvent.
In the mixed solvent of water and organic solvent, the mixing ratio of water and organic solvent is 20/80 to 80/20, preferably 40/60 to 60/40, and particularly preferably 50/50 in terms of mass ratio. .
Specific examples of the organic solvent include 2-propanol, methanol, ethanol, 1-methoxy-2-propanol, ethyl lactate, diacetone alcohol, methyl 3-methoxypropionate, and ethyl 3-ethoxypropionate. Of these, 2-propanol, methanol, or ethanol is preferable as the organic solvent, and 2-propanol is particularly preferable from the viewpoint of the solubility of the decomposition product generated by ultraviolet irradiation.

In the step of applying the liquid crystal aligning agent to the substrate and baking, the polyimide film or the polyimide precursor film is obtained by applying the liquid crystal aligning agent of the present invention to the substrate, drying and baking.
The substrate on which the liquid crystal aligning agent is applied is not particularly limited as long as it is a highly transparent substrate, and a glass substrate, a silicon nitride substrate, a plastic substrate such as an acrylic substrate or a polycarbonate substrate, or the like can be used. In particular, it is preferable to use a substrate on which an ITO (Indium Tin Oxide) electrode or the like for driving a liquid crystal is formed from the viewpoint of simplification of the process. In the reflective liquid crystal display element, an opaque object such as a silicon wafer can be used as long as it is only on one side of the substrate. In this case, a material that reflects light such as aluminum can be used for the electrode. Examples of the method for applying the liquid crystal aligning agent used in the present invention include a spin coating method, a printing method, and an ink jet method.
Arbitrary temperature and time can be selected for the drying and baking steps after applying the liquid crystal aligning agent of the present invention. Usually, in order to fully remove the organic solvent contained, conditions of baking at 50 to 120 ° C. for 1 to 10 minutes and then baking at 150 to 300 ° C. for 5 to 120 minutes can be mentioned.
Although the thickness of the coating film after baking is not specifically limited, Since the reliability of a liquid crystal display element may fall when too thin, it is 5-300 nm, Preferably it is 10-200 nm.

<Liquid crystal display element>
The liquid crystal display element of this invention comprises the liquid crystal aligning film obtained by the manufacturing method of the said liquid crystal aligning film. In the liquid crystal display element of the present invention, after obtaining a substrate with a liquid crystal alignment film by the method for producing a liquid crystal alignment film, a liquid crystal cell is prepared by a known method, and the liquid crystal cell is used as a liquid crystal display element. It is.
As an example of a method for manufacturing a liquid crystal cell, a liquid crystal display element having a passive matrix structure will be described as an example. Note that this manufacturing method can also be applied to an active matrix liquid crystal display element in which a switching element such as a TFT (thin film transistor) is provided in each pixel portion constituting an image display.

First, a transparent glass substrate is prepared, a common electrode is provided on one substrate, and a segment electrode is provided on the other substrate. These electrodes can be ITO electrodes, for example, and are patterned so as to display a desired image. Next, an insulating film is provided on each substrate so as to cover the common electrode and the segment electrode. The insulating film can be, for example, a film made of SiO ₂ —TiO ₂ formed by a sol-gel method.
Next, the liquid crystal alignment film of the present invention is formed on each substrate. Next, the other substrate is superposed on one substrate so that the alignment film surfaces face each other, and the periphery is bonded with a sealant. In order to control the substrate gap, a spacer is usually mixed in the sealant. Further, it is preferable that spacers for controlling the gap between the substrates are also sprayed on the in-plane portion where no sealant is provided. A part of the sealant is provided with an opening that can be filled with liquid crystal from the outside.

Next, a liquid crystal material is injected into a space surrounded by the two substrates and the sealant through an opening provided in the sealant. Thereafter, the opening is sealed with an adhesive. For the injection, a vacuum injection method may be used, or a method utilizing capillary action in the atmosphere may be used. Next, a polarizing plate is installed. Specifically, a pair of polarizing plates is attached to the surfaces of the two substrates opposite to the liquid crystal layer. By passing through the above process, the liquid crystal display element of this invention is obtained.
In the present invention, as the sealant, for example, a resin that is cured by ultraviolet irradiation or heating having a reactive group such as an epoxy group, an acryloyl group, a methacryloyl group, a hydroxyl group, an allyl group, or an acetyl group is used. In particular, it is preferable to use a cured resin system having reactive groups of both an epoxy group and a (meth) acryloyl group.

  In the sealing agent of the present invention, an inorganic filler may be blended for the purpose of improving adhesiveness, moisture resistance and the like. Although it does not specifically limit as an inorganic filler which can be used, Specifically, spherical silica, fused silica, crystalline silica, titanium oxide, titanium black, silicon carbide, silicon nitride, boron nitride, calcium carbonate, magnesium carbonate, barium sulfate , Calcium sulfate, mica, talc, clay, alumina, magnesium oxide, zirconium oxide, aluminum hydroxide, calcium silicate, aluminum silicate, lithium aluminum silicate, zirconium silicate, barium titanate, glass fiber, carbon fiber, molybdenum disulfide, asbestos Etc. Preferably, spherical silica, fused silica, crystalline silica, titanium oxide, titanium black, silicon nitride, boron nitride, calcium carbonate, barium sulfate, calcium sulfate, mica, talc, clay, alumina, aluminum hydroxide, calcium silicate, aluminum silicate Etc. Two or more inorganic fillers may be mixed and used.

The present invention will be described in more detail with reference to examples below, but the present invention is not limited thereto.
Abbreviations in the following are as follows.
NMP: N-methyl-2-pyrrolidone BCS: Butyl cellosolve tetracarboxylic acid derivative A to C: Compounds represented by the following formulas (A) to (C), respectively

DA-1 to DA-6: Compounds DBOP represented by the following formulas (DA-1) to (DA-6) respectively: Diphenyl (2,3-dihydro-2-thioxo-3-benzoxazolyl) Phosphonate

２−（４−ニトロフェニル）エチルアミン塩酸塩（５０．０ｇ，２４７ｍｍｏｌ）を水（３００ｇ）及びＤＭＦ（５０．０ｇ）に溶解し、炭酸ナトリウム（７８．４ｇ，７４０ｍｍｏｌ）を加え、４−ニトロベンジルブロミド（５３．３ｇ，２４７ｍｍｏｌ）のＤＭＦ溶液（２００ｇ）を、２５℃で１時間かけて滴下した。滴下中、ＤＭＦ／水＝１／１（ｗ／ｗ、１００ｇ）を追加し、析出物による撹拌不良を解消した。そのまま室温で２０時間撹拌し、さらに、４０℃で４時間撹拌した後、ＨＰＬＣで原料の消失を確認した。その後、反応液を室温に放冷し、析出物をろ取した。次いで、析出物を水（１５０ｇ）で２回、２−プロパノール（５０．０ｇ）で２回洗浄し、５０℃で減圧乾燥して、Ｎ−２−（４−ニトロフェニル）エチル−Ｎ−（４−ニトロベンジル）アミン(ＤＡ−５−１)を得た（白色固体、収量：７３ｇ、収率：９９％）。(Synthesis of DA-5)
First step: Synthesis of N-2- (4-nitrophenyl) ethyl-N- (4-nitrobenzyl) amine (DA-5-1)

2- (4-Nitrophenyl) ethylamine hydrochloride (50.0 g, 247 mmol) was dissolved in water (300 g) and DMF (50.0 g), sodium carbonate (78.4 g, 740 mmol) was added, and 4-nitrobenzyl was added. A DMF solution (200 g) of bromide (53.3 g, 247 mmol) was added dropwise at 25 ° C. over 1 hour. During the dropwise addition, DMF / water = 1/1 (w / w, 100 g) was added to eliminate poor stirring due to precipitates. The mixture was stirred at room temperature for 20 hours and further stirred at 40 ° C. for 4 hours, and then disappearance of raw materials was confirmed by HPLC. Thereafter, the reaction solution was allowed to cool to room temperature, and the precipitate was collected by filtration. The precipitate was then washed twice with water (150 g), twice with 2-propanol (50.0 g), dried under reduced pressure at 50 ° C., and N-2- (4-nitrophenyl) ethyl-N- ( 4-Nitrobenzyl) amine (DA-5-1) was obtained (white solid, yield: 73 g, yield: 99%).

Hereinafter, confirmation of the obtained compound was performed by obtaining the following spectral data by ¹ H-NMR analysis and ¹³ C { ¹ H} -NMR analysis.
¹ H-NMR was measured using a Fourier transform superconducting nuclear magnetic resonance apparatus (FT-NMR) INOVA-400 (400 MHz) manufactured by Varian, and signal chemical shift using tetramethylsilane as an internal standard. It represents δ (unit: ppm) (fission pattern, integral value). “S” is singlet, “d” is doublet, “t” is triplet, “q” is quartet, “m” is multiplet, “br” is broad, “J” is coupling constant, “DMSO-d ₆ "Means deuterated dimethyl sulfoxide.
¹³ C { ¹ H} -NMR was measured using a Fourier transform superconducting nuclear magnetic resonance apparatus (FT-NMR) INOVA-400 (400 MHz) manufactured by Varian, and tetramethylsilane was used as an internal standard. It represents the chemical shift δ (unit: ppm) of the signal.

¹ H NMR (DMSO-d ₆ ): δ 8.18 (d, J = 8.8 Hz, 2H, C ₆ H ₄ ), 8.15 (d, J = 8.8 Hz, 2H, C ₆ H ₄ ), 7.59, (d, J = 8.8 Hz, 2H, C ₆ H ₄ ), 7.52 (d, J = 8.8 Hz, 2H, C ₆ H ₄ ), 3.87 (s, 2H, CH ₂ ), 2.91 (t, J = 7.0 Hz, 2H , CH ₂ ), 2.80 (t, J = 7.0 Hz, 2H, CH ₂ ), 2.46 (s, 1H, NH).
¹³ C { ¹ H} NMR (DMSO-d ₆ ): δ 149.8, 149.5, 146.6, 146.3, 130.3, 129.2, 123.7, 123.6, 52.4, 50.0, 36.0 (each s).
Melting point (DSC): 123 ° C

Ｎ−２−（４−ニトロフェニル）エチル−Ｎ−４−ニトロベンジルアミン（７３ｇ，０．２４ｍｏｌ）をＤＭＦ（３７１ｇ）に溶解し、二炭酸ジｔｅｒｔ−ブチル（５４ｇ，０．２４ｍｏｌ）を２〜８℃で１０分かけて滴下した。その後、２０℃で４時間撹拌し、原料の消失をＨＰＬＣで確認した。続いて、ＤＭＦを減圧留去し、反応液に酢酸エチル（３７１ｇ）を加え、水（３７１ｇ）で３回洗浄した。その後、有機相を濃縮し、オレンジ色オイルを得た（粗収量：９６ｇ，粗収率：９７％）。この粗物を、シリカゲルカラムクロマトグラフィー（ヘキサン／酢酸エチル＝７／３（ｖ／ｖ，Ｒｆ値＝０．３）で精製して黄色オイルを得た。（粗収量：８２．０ｇ、粗収率：８２．８％（２ステップ））。この黄色オイルにメタノール（１１８ｇ）を加え、５０℃で溶解させた後、撹拌しながら冷却し、０〜５℃で３０分撹拌した。その後、析出した固体をろ取し、乾燥することで、Ｎ−ｔｅｒｔ−ブトキシカルボニル−Ｎ−２−（４−ニトロフェニル）エチル−Ｎ−４−ニトロベンジルアミン（ＤＡ−５−２）を得た（白色粉末, 収量：７４．５ ｇ, 収率：７８％（２ステップ））。Second Step: Synthesis of N-tert-butoxycarbonyl-N- (2- (4-nitrophenyl) ethyl) -N- (4-nitrobenzyl) amine (DA-5-2)

N-2- (4-nitrophenyl) ethyl-N-4-nitrobenzylamine (73 g, 0.24 mol) was dissolved in DMF (371 g), and ditert-butyl dicarbonate (54 g, 0.24 mol) was dissolved in 2 parts. It dripped over 10 minutes at -8 degreeC. Then, it stirred at 20 degreeC for 4 hours, and the loss | disappearance of the raw material was confirmed by HPLC. Subsequently, DMF was distilled off under reduced pressure, ethyl acetate (371 g) was added to the reaction solution, and the mixture was washed 3 times with water (371 g). Thereafter, the organic phase was concentrated to obtain an orange oil (crude yield: 96 g, crude yield: 97%). This crude product was purified by silica gel column chromatography (hexane / ethyl acetate = 7/3 (v / v, Rf value = 0.3)) to obtain a yellow oil (crude yield: 82.0 g, crude yield). Rate: 82.8% (2 steps)) Methanol (118 g) was added to this yellow oil, dissolved at 50 ° C., cooled with stirring, and stirred at 0-5 ° C. for 30 minutes. The obtained solid was collected by filtration and dried to obtain N-tert-butoxycarbonyl-N-2- (4-nitrophenyl) ethyl-N-4-nitrobenzylamine (DA-5-2) (white) Powder, yield: 74.5 g, yield: 78% (2 steps)).

¹ H NMR (DMSO-d ₆ ): δ 8.22 (d, J = 8.4 Hz, 2H, C ₆ H ₄ ), 8.18-8.16 (br, 2H, C ₆ H ₄ ), 7.51 (d, J = 8.4 Hz , 2H, C ₆ H ₄ ), 7.48 (br, 2H, C ₆ H ₄ ), 4.57-4.54 (br, 2H, CH ₂ ), 3.55-3.49 (br, 2H, CH ₂ ), 2.97 (br, 2H , CH ₂ ), 1.36-1.32 (br, 9H, tert-Bu).
¹³ C { ¹ H} NMR (DMSO-d ₆ ): δ 155.2, 154.8, 147.9, 147.5, 147.1, 147.0, 146.5, 130.6, 128.7, 128.4, 124.0, 123.8, 79.7, 50.3, 49.2, 48.4, 34.3, 34.0 , 28.2 (each s).
Melting point (DSC): 77 ° C

Ｎ−ｔｅｒｔ−ブトキシカルボニル−Ｎ−２−（４−ニトロフェニル）エチル−Ｎ−４−ニトロベンジルアミン（７４ｇ，０．１８ｍｏｌ）をテトラヒドロフラン（３７０ｇ）に溶解し、３質量％白金−炭素（７．４ｇ）を加え、水素雰囲気下、室温で７２時間撹拌した。原料の消失をＨＰＬＣで確認し、ろ過により触媒を除去した。その後、ろ液を濃縮し、乾燥することで、ＤＡ−５の粗物を薄黄色オイルとして得た（粗収量：６６ｇ、粗収率：１０５％）。得られた粗物をトルエン（１９８ｇ）に８０℃で溶解した後、２℃で１時間撹拌して結晶を析出させた。析出した固体をろ取し、乾燥することでＤＡ−５を得た（白色粉末、収量：５６ｇ、収率：９０％）。Third Step: Synthesis of N-tert-butoxycarbonyl-N- (2- (4-aminophenyl) ethyl) -N- (4-aminobenzyl) amine (DA-5)

N-tert-butoxycarbonyl-N-2- (4-nitrophenyl) ethyl-N-4-nitrobenzylamine (74 g, 0.18 mol) was dissolved in tetrahydrofuran (370 g), and 3% by mass platinum-carbon (7 4 g) was added and stirred at room temperature for 72 hours under a hydrogen atmosphere. The disappearance of the raw materials was confirmed by HPLC, and the catalyst was removed by filtration. Thereafter, the filtrate was concentrated and dried to obtain a DA-5 crude product as a pale yellow oil (crude yield: 66 g, crude yield: 105%). The obtained crude product was dissolved in toluene (198 g) at 80 ° C., and then stirred at 2 ° C. for 1 hour to precipitate crystals. The precipitated solid was collected by filtration and dried to obtain DA-5 (white powder, yield: 56 g, yield: 90%).

¹ H NMR (DMSO-d ₆ ): δ 6.92 (d, J = 8.0 Hz, 2H, C ₆ H ₄ ), 6.84-6.76 (br, 2H, C ₆ H ₄ ), 6.54 (d, J = 8.0 Hz , 2H, C ₆ H ₄ ), 6.50 (d, J = 8.0 Hz, 2H, C ₆ H ₄ ), 4.98 (s, 2H, NH ₂ ), 4.84 (s, 2H, NH ₂ ), 4.16 (br, 2H, CH ₂ ), 3.13 (br, 2H, CH ₂ ), 2.51 (br, 2H, CH ₂ ), 1.41 (s, 9H, tert-Bu).
¹³ C { ¹ H} NMR (DMSO-d ₆ ): δ 155.4, 154.9, 148.2, 147.2, 129.5, 129.3, 129.1, 128.9, 126.6, 125.7, 114.5, 114.3, 78.9, 78.8, 50.2, 49.2, 48.4, 33.9 , 33.3, 28.5 (each s).
Melting point (DSC): 103 ° C

窒素雰囲気下、４口フラスコに、ジメチルホルムアミド（３９０ｇ）、４−フルオロニトロベンゼン（６５．０１g、０．４６０７mol）、４―アミノメチルピペリジン（２５．００ｇ、０．２１８９mol）、及び炭酸カリウム(９０．８９g、０．６５７６mol)を加え、６０℃で撹拌反応させた。２２時間加熱攪拌した後に、中間体の消失をＨＰＬＣで確認した。その後、室温まで冷却して、ろ過により炭酸カリウムを除去し、さらに、炭酸カリウムをジメチルホルムアミド２５０ｇで２回洗浄した。集めた溶液を、内容物が２９５ｇになるまで減圧留去し、次いで、水１５００ｇを加えて、黄色固体を析出させた。その後、析出物をろ過により回収し、乾燥して、ＤＡ−６−１の粗物を得た。得られた粗物をテトラヒドロフランにて再結晶して精製し、黄色固体のＤＡ−６−１を得た（５８．７５ｇ、０．１６４９mol、収率７５．３％）。(Synthesis of DA-6)
First step: Synthesis of DA-6-1

In a four-necked flask under a nitrogen atmosphere, dimethylformamide (390 g), 4-fluoronitrobenzene (65.01 g, 0.4607 mol), 4-aminomethylpiperidine (25.00 g, 0.2189 mol), and potassium carbonate (90. 89 g, 0.6576 mol) was added and the reaction was stirred at 60 ° C. After stirring for 22 hours, the disappearance of the intermediate was confirmed by HPLC. Then, it cooled to room temperature, the potassium carbonate was removed by filtration, and potassium carbonate was further washed twice with 250 g of dimethylformamide. The collected solution was distilled off under reduced pressure until the content became 295 g, and then 1500 g of water was added to precipitate a yellow solid. Thereafter, the precipitate was collected by filtration and dried to obtain a DA-6-1 crude product. The obtained crude product was purified by recrystallization from tetrahydrofuran to obtain DA-6-1 as a yellow solid (58.75 g, 0.1649 mol, yield 75.3%).

¹ H-NMR (DMSO-d ₆ ): δ = 8.05-7.98 (m, 4H), 7.41 (t, 1H J = 6.8), 7.02 (d, 2H, J = 9.6), 6.68 (d, 2H, J = 9.2), 4.09 (d, 2H, J = 13.6), 3.10 (t, 2H, J = 6.0), 2.98 (t, 2H, J = 12.0), 1.91-1.89 (m, 1H), 1.89-1.83 (m, 2H), 1.29-1.19 (m , 2H).

窒素雰囲気下、４口フラスコに、テトラヒドロフラン（４００ｇ）、ＤＡ−６−１（１９．９９g、０．０５６１mol）、及びＮ、Ｎ―ジメチル−４−アミノピリジン（７７．４４ｍｇ、０．６３４mmol）を加え、５０℃に加熱した。その溶液へ、二炭酸ジ-ｔｅｒｔ−ブチル(１５．２６g、０．０６９９mol)とテトラヒドロフラン１５ｇの混合液を滴下し、２４時間反応させた後、ＨＰＬＣにて原料が消失したことを確認した。内容物を減圧留去した後、トルエンで再結晶を行い、析出した結晶をろ取し、乾燥させて、黄色固体の化合物ＤＡ−６−２を収率８７．３％で得た（２２．３４ｇ、０．０４８９mol）。Second step: Synthesis of DA-6-2

Under a nitrogen atmosphere, tetrahydrofuran (400 g), DA-6-1 (19.99 g, 0.0561 mol), and N, N-dimethyl-4-aminopyridine (77.44 mg, 0.634 mmol) were added to a four-necked flask. In addition, it was heated to 50 ° C. A mixed solution of di-tert-butyl dicarbonate (15.26 g, 0.0699 mol) and tetrahydrofuran 15 g was dropped into the solution and reacted for 24 hours, and then it was confirmed by HPLC that the raw material had disappeared. After the content was distilled off under reduced pressure, recrystallization was performed with toluene, and the precipitated crystals were collected by filtration and dried to obtain a yellow solid compound DA-6-2 in a yield of 87.3% (22. 34 g, 0.0489 mol).

¹ H-NMR (DMSO-d ₆ ): δ = 8.21 (d, 2H, J = 8.8), 8.01 (d, 2H J = 9.2), 7.61 (d, 2H, J = 9.2), 6.98 (d, 2H, J = 9.6), 4.02 (d, 2H, J = 13.6), 3.69 (d, 2H, J = 7.2) ), 2.91 (t, 2H, J = 11.6), 1.86-1.70 (m, 1H), 1.66 (d, 2H, J = 11.2), 1.42 (s) , 9H), 1.22-1.10 (m, 2H).

窒素雰囲気下、４口フラスコに、テトラヒドロフラン（４４７ｇ）、ＤＡ−６−２（２２．３４g、０．０４８９mol）、及びパラジウムカーボン粉末（１．１５６ｇ）を入れた後、系内を水素雰囲気に置換し、室温で２３時間攪拌した。ＨＰＬＣにて原料が消失したことを確認した後、パラジウムカーボンをろ過し、得られた溶液を減圧留去して粗物を得た。得られた粗物にクロロホルム（２０６ｇ）を加え、６０℃に加温した後、６０℃の水（１００ｇ）で２回分液操作を繰り返した。次いで、得られた有機層に活性炭（０．７５４ｇ）を加え、攪拌した後、ろ過により活性炭を除去した。内容物を減圧濃縮し、得られた固体をトルエンで再結晶を行った。その後、得られた結晶を乾燥させて、薄クリーム色固体の目的物、（ＤＡ−６）を収率７１．３％で得た（１３．８３ｇ、０．０３４９mol）。Step 3: Synthesis of DA-6

In a nitrogen atmosphere, tetrahydrofuran (447 g), DA-6-2 (22.34 g, 0.0489 mol), and palladium carbon powder (1.156 g) were placed in a four-necked flask, and the system was replaced with a hydrogen atmosphere. And stirred at room temperature for 23 hours. After confirming disappearance of the raw material by HPLC, palladium carbon was filtered, and the resulting solution was distilled off under reduced pressure to obtain a crude product. Chloroform (206 g) was added to the resulting crude product and heated to 60 ° C., and then the liquid separation operation was repeated twice with 60 ° C. water (100 g). Next, activated carbon (0.754 g) was added to the obtained organic layer and stirred, and then the activated carbon was removed by filtration. The contents were concentrated under reduced pressure, and the resulting solid was recrystallized from toluene. Thereafter, the obtained crystals were dried to obtain a light cream solid target product (DA-6) in a yield of 71.3% (13.83 g, 0.0349 mol).

¹ H-NMR (DMSO-d ₆ ): δ = 6.83 (d, 2H, J = 8.0), 6.65 (d, 2H J = 8.4), 6.50 (d, 2H, J = 8.4), 6.45 (d, 2H, J = 8.4), 5.05 (br, 2H), 4.54 (br, 2H), 3.41 (d, 2H, J = 6.8), 3.29 (d, 2H, J = 12.4), 2.36 (t, 2H, J = 10.8), 1.64 (d, 2H, J = 11.6), 1.42-1.19 (br, 12H).

Below, the measuring method of a viscosity, solid content concentration, and molecular weight is shown.
[viscosity]
As for the viscosity of the polyamic acid solution or the polyamic acid ester solution, an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.) was used, a sample amount of 1.1 mL, cone rotor TE-1 (1 ° 34 ′, R24), temperature Measured at 25 ° C.

[Molecular weight]
The molecular weights of the polyamic acid and the polyamic acid ester are measured by a GPC (room temperature gel permeation chromatography) apparatus, and the number average molecular weight (hereinafter also referred to as Mn) and the weight average molecular weight (hereinafter, referred to as Mn) as polyethylene glycol and polyethylene oxide equivalent values. Mw.) Was calculated.
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 additives, lithium bromide-hydrate (LiBr · H 2 O) 30 mmol / L, phosphoric acid / anhydrous crystal (o-phosphoric acid) 30 mmol / L, tetrahydrofuran (THF ) Is 10ml / L)
Flow rate: 1.0 ml / min Standard sample for preparing a calibration curve: TSK manufactured by Tosoh Corporation (standard polyethylene oxide (weight average molecular weight (Mw) is about 900,000, 150,000, 100,000, and 30,000)) and polyethylene manufactured by Polymer Laboratory Glycol (peak top molecular weight (Mp) of about 12,000, 4,000, and 1,000). In order to avoid overlapping peaks, the measurement was performed separately for two samples: 900,000, 100,000, 12,000, and 1,000 mixed samples, and 150,000, 30,000, and 4,000 mixed samples. .

(Synthesis Example 1)
After putting 11.22 g (43.1 mmol) of (A) into a four-necked flask containing a stirring bar, 265 g of NMP was added and stirred to dissolve. Then, 13.36 g (132 mmol) of triethylamine, 5.57 g (24.2 mmol) of DA-1, 1.97 g (6.6 mmol) of DA-3, and 9.02 g (26.4 mmol) of DA-5 In addition, it was dissolved by stirring.
While stirring this solution, 33.9 g (88.4 mmol) of DBOP was added, and 36.4 g of NMP was further added, followed by stirring at room temperature for 12 hours to obtain a polyamic acid ester solution. The viscosity of this polyamic acid ester solution at a temperature of 25 ° C. was 42.6 mPa · s.

This polyamic acid ester solution was put into 2260 g of methanol, and the resulting precipitate was separated by filtration. The precipitate was washed with methanol and then dried under reduced pressure at a temperature of 100 ° C. to obtain a polyamic acid ester powder. The molecular weight of this polyamic acid ester was Mn = 12,601 and Mw = 29,033.
NMP was added to the obtained polyamic acid ester powder and dissolved by stirring at 50 ° C. for 30 hours, and then NMP and BCS were added. The polyamic acid ester was 6% by mass, NMP was 69% by mass, and BCS was 25%. The polyamic acid ester solution (A) was prepared so that it might become mass%.

(Synthesis Example 2)
After adding 2.55 g (9.80 mmol) of (A) to a four-necked flask containing a stir bar, 45.0 g of NMP was added and stirred to dissolve. Next, 2.13 g (21.0 mmol) of triethylamine, 1.96 g (8.50 mmol) of DA-1, and 0.45 g (1.50 mmol) of DA-3 were added and dissolved by stirring.
While stirring this solution, 8.05 g (21.0 mmol) of DBOP was added, and 7.94 g of NMP was further added, followed by stirring at room temperature for 12 hours to obtain a polyamic acid ester solution. The viscosity of this polyamic acid ester solution at a temperature of 25 ° C. was 50.0 mPa · s.
This polyamic acid ester solution was put into 408 g of methanol, and the resulting precipitate was separated by filtration. The precipitate was washed with methanol and then dried under reduced pressure at a temperature of 100 ° C. to obtain a polyamic acid ester powder. The molecular weight of this polyamic acid ester was Mn = 12,542 and Mw = 35,098.
NMP was added to the obtained polyamic acid ester powder and dissolved by stirring at 50 ° C. for 30 hours, and then NMP and BCS were added. The polyamic acid ester was 6% by mass, NMP was 69% by mass, and BCS was 25%. The polyamic acid ester solution (B) was prepared so that it might become mass%.

(Synthesis Example 3)
In a four-necked flask containing a stir bar, DA-2 was 3.52 g (12.0 mmol), DA-4 was 0.96 g (5.00 mmol), and DA-6 was 1.90 g (4.8 mmol). After charging, 67.8 g of NMP was added and stirred to dissolve. Next, 1.13 g (5.30 mmol) of (C) was added, and the mixture was stirred at room temperature for 2 hours. Thereafter, 3.66 g (16.8 mmol) of (B) was added, and then 22.60 g of NMP was added and reacted at 50 ° C. for 15 hours to obtain a polyamic acid solution. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 152 mPa · s. The molecular weight of this polyamic acid was Mn = 13,100 and Mw = 34,500.
NMP and BCS were added to the obtained polyamic acid solution so that the polyamic acid was 6% by mass, NMP was 69% by mass, and BCS was 25% by mass to prepare a polyamic acid solution (A).

(Synthesis Example 4)
In a four-necked flask containing a stir bar, DA-2 2.05 g (8.4 mmol), DA-4 0.84 g (4.20 mmol), and DA-6 0.55 g (1.4 mmol). After charging, 33.87 g of NMP was added and stirred to dissolve. Next, 0.66 g (3.40 mmol) of (C) was added, and the mixture was stirred at room temperature for 2 hours. Thereafter, 2.13 g (9.8 mmol) of (B) was added, and then 11.29 g of NMP was added and reacted at 50 ° C. for 15 hours to obtain a polyamic acid solution. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 172 mPa · s. The molecular weight of this polyamic acid was Mn = 13,800 and Mw = 35,800.
NMP and BCS were added to the obtained polyamic acid solution so that the polyamic acid was 6% by mass, NMP was 69% by mass, and BCS was 25% by mass to prepare a polyamic acid solution (B).

(Synthesis Example 5)
After adding 4.66 g (15.0 mmol) of DA-2 and 1.99 g (10.0 mmol) of DA-4 to a four-necked flask containing a stirring bar, 69.24 g of NMP was added and stirred. Dissolved. Next, 1.18 g (6.0 mmol) of (C) was added, and the mixture was stirred at room temperature for 2 hours. Then, 3.82 g (17.5 mmol) of (B) was added, then 23.08 g of NMP was added and reacted at 50 ° C. for 15 hours to obtain a polyamic acid solution. The viscosity of this polyamic acid solution at a temperature of 25 ° C. was 105 mPa · s. The molecular weight of this polyamic acid was Mn = 11,300 and Mw = 28,600.
NMP and BCS were added to the obtained polyamic acid solution so that the polyamic acid was 6% by mass, NMP was 69% by mass, and BCS was 25% by mass to prepare a polyamic acid solution (C).

Example 1
In a conical flask containing a stirrer, 8.10 g of the polyamic acid ester solution (A) obtained in Synthesis Example 1 and 12.1 g of the polyamic acid solution (A) obtained in Synthesis Example 3 were placed at room temperature. Was stirred for 3 hours to obtain a liquid crystal aligning agent (A-1).

(Example 2)
In a conical flask containing a stirrer, 8.00 g of the polyamic acid ester solution (A) obtained in Synthesis Example 1 and 12.1 g of the polyamic acid solution (B) obtained in Synthesis Example 4 were placed at room temperature. And stirred for 3 hours to obtain a liquid crystal aligning agent (A-2).

(Comparative Example 1)
In a conical flask containing a stirrer, 7.99 g of the polyamic acid ester solution (B) obtained in Synthesis Example 2 and 12.1 g of the polyamic acid solution (C) obtained in Synthetic Example 5 were placed at room temperature. And stirred for 3 hours to obtain a liquid crystal aligning agent (B-1).

(Comparative Example 2)
In a conical flask containing a stirrer, 8.01 g of the polyamic acid ester solution (A) obtained in Synthesis Example 1 and 12.0 g of the polyamic acid solution (C) obtained in Synthesis Example 5 were placed at room temperature. And stirred for 3 hours to obtain a liquid crystal aligning agent (B-2).

<Production of liquid crystal cell>
A liquid crystal cell having the configuration of the FFS mode liquid crystal display element was manufactured as follows.
First, a substrate with electrodes was prepared. The substrate is a glass substrate having a size of 30 mm × 35 mm and a thickness of 0.7 mm. On the substrate, an IZO (Indium Zinc Oxide) electrode having a solid pattern, which forms a counter electrode as a first layer, is formed. On the counter electrode of the first layer, a SiN (silicon nitride) film formed by a CVD (chemical vapor deposition) method is formed as the second layer. The second layer SiN film has a thickness of 500 nm and functions as an interlayer insulating film. On the second SiN film, a comb-like pixel electrode formed by patterning an IZO film as the third layer is arranged to form two pixels, a first pixel and a second pixel. doing. The size of each pixel is 10 mm long and about 5 mm wide. At this time, the first-layer counter electrode and the third-layer pixel electrode are electrically insulated by the action of the second-layer SiN film.

The pixel electrode of the third layer has a comb-like shape configured by arranging a plurality of electrode elements having a dogleg shape whose central portion is bent. The width in the short direction of each electrode element is 3 μm, and the distance between the electrode elements is 6 μm. Since the pixel electrode forming each pixel is configured by arranging a plurality of bent-shaped electrode elements in the central portion, the shape of each pixel is not rectangular, but the central portion is similar to the electrode element. It has a shape similar to that of a bold-faced koji that bends at Furthermore, each pixel is divided into upper and lower portions with a central bent portion as a boundary, and has a first region on the upper side of the bent portion and a second region on the lower side.
When the first region and the second region of each pixel are compared, the formation directions of the electrode elements of the pixel electrodes constituting them are different. That is, when the rubbing direction of the liquid crystal alignment film to be described later is used as a reference, in the first region of the pixel, the electrode element of the pixel electrode is formed to form an angle of + 10 ° (clockwise), and in the second region of the pixel The electrode elements of the pixel electrode are formed at an angle of −10 ° (clockwise). That is, in the first region and the second region of each pixel, the direction of the rotation operation (in-plane switching) in the substrate surface of the liquid crystal induced by the voltage application between the pixel electrode and the counter electrode is It is comprised so that it may become a mutually reverse direction.

  Next, after filtering the obtained liquid crystal aligning agent with a 1.0 micrometer filter, it apply | coated to the prepared said board | substrate with an electrode by spin coat application | coating. After drying on an 80 ° C. hot plate for 5 minutes, baking was performed in a hot air circulation oven at 230 ° C. for 30 minutes to obtain a polyimide film having a thickness of 60 nm. This polyimide film is rubbed with a rayon cloth (roller diameter: 120 mm, roller rotation speed: 500 rpm, moving speed: 30 mm / sec, indentation length: 0.3 mm, rubbing direction: 10 ° with respect to the third-layer IZO comb-teeth electrode (Inclined direction), and then washed by irradiating with ultrasonic waves in pure water for 1 minute to remove water droplets by air blow. Then, it dried for 15 minutes at 80 degreeC, and obtained the board | substrate with a liquid crystal aligning film. Also, as a counter substrate, a polyimide film is formed on a glass substrate having a columnar spacer with a height of 4 μm on which an ITO electrode is formed on the back surface in the same manner as described above. A substrate with a liquid crystal alignment film to which was applied was obtained.

One set of these two substrates with a liquid crystal alignment film is printed, and the sealant is printed on the substrate leaving the liquid crystal injection port. The other substrate has the liquid crystal alignment film surface facing and the rubbing direction is antiparallel. Then, the sealing agent was cured to produce an empty cell having a cell gap of 4 μm. Liquid crystal MLC-2041 (manufactured by Merck & Co., Inc.) was injected into this empty cell by a reduced pressure injection method, and the injection port was sealed to obtain an FFS liquid crystal cell. Thereafter, the obtained liquid crystal cell was heated at 110 ° C. for 1 hour and left at 23 ° C. overnight before being used for each evaluation.
The following are evaluation methods for the accumulated charge relaxation characteristics, the accumulated charge amount due to the asymmetry of the positive and negative voltages during AC driving, the voltage holding ratio (VHR) backlight aging resistance, and the rubbing resistance.

<Evaluation of relaxation characteristics of accumulated charge>
The liquid crystal cell is placed between two polarizing plates arranged so that their polarization axes are orthogonal to each other, and the pixel electrode and the counter electrode are short-circuited to be at the same potential, and the LED is displayed from under the two polarizing plates. The angle of the liquid crystal cell was adjusted so that the brightness of the LED backlight transmitted light measured on the two polarizing plates was minimized by irradiating the backlight.
Next, while applying a rectangular wave with a frequency of 30 Hz to this liquid crystal cell, the VT characteristics (voltage-transmittance characteristics) at a temperature of 23 ° C. are measured, and an AC voltage with a relative transmittance of 23% is measured. Calculated.
Next, a rectangular wave having a relative transmittance of 23% and a frequency of 30 Hz was applied for 5 minutes, and then a +1.0 V DC voltage was superimposed and driven for 30 minutes. Thereafter, the DC voltage was turned off, and only an AC voltage with a relative transmittance of 23% and a rectangular wave with a frequency of 30 Hz was applied for 20 minutes.
The faster the accumulated charge is relaxed, the faster the charge accumulation in the liquid crystal cell when the DC voltage is superimposed. Therefore, the accumulated charge relaxation characteristic is a state where the relative transmittance immediately after the DC voltage is superimposed is 30% or more. In the case where the relative transmittance decreased to less than 28% by the time 30 minutes passed, the evaluation was defined as “good”. When the relative transmittance did not decrease to less than 28% even after 30 minutes had elapsed since the DC voltage was superimposed, the evaluation was defined as “defective”.

<Evaluation of accumulated charge by asymmetry of positive and negative voltages during AC drive>
The liquid crystal cell is placed between two polarizing plates arranged so that their polarization axes are orthogonal to each other, and the pixel electrode and the counter electrode are short-circuited to be at the same potential, and the LED is displayed from under the two polarizing plates. The angle of the liquid crystal cell was adjusted so that the brightness of the LED backlight transmitted light measured on the two polarizing plates was minimized by irradiating the backlight.
Next, VT characteristics (voltage-transmittance characteristics) at a temperature of 60 ° C. are measured while applying a rectangular wave having a frequency of 30 Hz to the liquid crystal cell, and the relative transmittance becomes 23% and 100%. AC voltage was calculated. Thereafter, the pixel electrode and the counter electrode were short-circuited and kept at the same potential and left for 60 minutes or more, and the charge accumulated in the liquid crystal cell was released.
Next, a rectangular wave having an AC voltage with a relative transmittance of 100% and a frequency of 30 Hz was applied for 30 minutes. However, in the 30 minutes, the AC voltage was switched to an AC voltage at which the relative transmittance was 23% only for 20 seconds every 3 minutes. VF characteristics (DC voltage-flicker characteristics) are measured during 20 seconds when the AC voltage is switched to an AC voltage at which the relative transmittance is 23%, and driving is performed at an AC voltage at which the relative transmittance is 100%. The DC voltage value that cancels the accumulated charge due to the asymmetry of the positive and negative voltages was recorded. Since the smaller the absolute value of the DC voltage value that cancels this accumulated charge, the less the charge is accumulated due to the AC voltage drive, the afterimage characteristics are considered to be better.

<Evaluation of Voltage Holding Ratio (VHR) Backlight Aging Resistance>
The backlight aging resistance (voltage holding ratio 1) of VHR was evaluated as follows.
First, a substrate with electrodes was prepared. The substrate is a glass substrate having a size of 30 mm × 40 mm and a thickness of 1.1 mm. An ITO electrode having a film thickness of 35 nm is formed on the substrate, and the electrode is a stripe pattern having a length of 40 mm and a width of 10 mm. Next, the liquid crystal aligning agent was filtered through a 1.0 μm filter, and then applied to the prepared substrate with electrodes by spin coating. After drying on a hot plate at 50 ° C. for 5 minutes, baking was performed in an IR oven at 230 ° C. for 20 minutes to form a coating film having a thickness of 100 nm to obtain a substrate with a liquid crystal alignment film. This liquid crystal alignment film is rubbed with a rayon cloth (roller diameter: 120 mm, roller rotation speed: 1000 rpm, moving speed: 20 mm / sec, indentation length: 0.4 mm), and then irradiated with ultrasonic waves in pure water for 1 minute. Then, washing was performed and water droplets were removed by air blow. Then, it dried for 15 minutes at 80 degreeC, and obtained the board | substrate with a liquid crystal aligning film. Prepare two substrates with this liquid crystal alignment film, spray 4μm spacers on the surface of one liquid crystal alignment film, print the sealant from the top, and rub the other substrate in the reverse direction. And after bonding together so that the film surfaces face each other, the sealing agent was cured to produce an empty cell.

Liquid crystal ZLI-4792 (manufactured by Merck) was injected into this empty cell by a reduced pressure injection method, and the injection port was sealed to obtain a liquid crystal cell. Thereafter, the obtained liquid crystal cell was heated at 110 ° C. for 1 hour and left at 23 ° C. overnight to obtain a liquid crystal cell for VHR measurement. The cell was then aged for 72 hours in a 70 ° C. oven under an LED light source (1000 cd).
After backlight aging for 72 hours, a voltage of 1V was applied to the cell at a temperature of 60 ° C. for 60 μsec, the voltage after 100 msec was measured, and how much the voltage was maintained was defined as VHR. The VHR backlight aging resistance was evaluated. That is, if the value of VHR is large, the VHR backlight aging resistance is good.

<Rubbing resistance>
The liquid crystal aligning agent was spin-coated on the ITO surface of a glass substrate having an ITO electrode on the entire surface, and dried on a hot plate at 50 ° C. for 5 minutes. Thereafter, baking was performed in an IR oven at 230 ° C. for 20 minutes to form a coating film having a film thickness of 100 nm to obtain a substrate with a liquid crystal alignment film. This liquid crystal alignment film was rubbed with a rayon cloth (roller diameter: 120 mm, roller rotation speed: 1000 rpm, moving speed: 20 mm / sec, indentation length: 0.4 mm). The substrate was observed with a microscope, and the film surface was evaluated as “good” when no rubbing streaks were observed on the film surface, and “bad” when streaks were observed.

A liquid crystal display element having a liquid crystal alignment film obtained from the liquid crystal aligning agent of the present invention is excellent in suppression of afterimages by long-term alternating current driving, and is useful as a liquid crystal display element of an IPS or FFS driving system.
The entire contents of the specification, claims, and abstract of Japanese Patent Application No. 2014-113191 filed on May 30, 2014 are incorporated herein as the disclosure of the specification of the present invention. Is.

Claims (8)

Liquid crystal aligning agent containing the following (A) component and (B) component.
(A) Component: Polyamic acid ester obtained by reacting a diamine component containing a diamine having the structure of the following formula [1] with a tetracarboxylic acid diester component having the structure of the following formula [2].
(B) Component: Polyamic acid obtained by reacting a diamine component containing a diamine represented by the following formula [3] with a tetracarboxylic dianhydride component containing an aromatic tetracarboxylic dianhydride.

(A ¹ and A ⁵ are each independently a single bond or an alkylene group having 1 to 5 carbon atoms, and A ² and A ⁴ are each independently an alkylene group having 1 to 5 carbon atoms. , A ³ is an alkylene group having 1 to 6 carbon atoms or a cycloalkylene group, and B ¹ and B ² are each independently a single bond, —O—, —NH—, —NMe—, —C ( = O)-, -C (= O) O-, -C (= O) NH-, -C (= O) NMe-, -OC (= O)-, -NHC (= O)-, or- N (Me) C (═O) —, D ₁ is a tert-butoxycarbonyl group, or a 9-fluorenylmethoxycarbonyl group, and a is 0 or 1.)

(R ₁ , R ₂ , R ₃ and R ₄ 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, or an alkynyl group having 2 to 6 carbon atoms. Group or phenyl group.)

(R ₅ represents a hydrogen atom or a monovalent organic group. Q 1 represents an alkylene group having 1 to 5 carbon atoms, and Cy represents an aliphatic heterocyclic ring having an azetidine, pyrrolidine, piperidine, or hexamethyleneimine skeleton. A substituent may be bonded to these ring portions, R ₆ and R ₇ are each independently a monovalent organic group, q and r are And each independently represents an integer of 0 to 4. However, when the sum of q and r is 2 or more, a plurality of R ₆ and R ₇ each independently have the above definition.) The liquid crystal aligning agent of Claim 1 in which the diamine component for obtaining (A) component and (B) component further contains the diamine which has a structure of following formula [4].

(N is an integer of 1 to 3)   The liquid crystal aligning agent of Claim 1 or 2 with which the diamine which has a structure of the said Formula [1] is contained 1-60 mol% in all the diamine components used in order to obtain (A) component.   The liquid crystal according to any one of claims 1 to 3, wherein the diamine represented by the formula [3] is contained in an amount of 1 to 60 mol% in all diamine components used for obtaining the component (B). Alignment agent.   The liquid crystal aligning agent of any one of Claims 1-4 which contains (A) component and (B) component by mass ratio of 10: 90-90: 10.   The diamine having the structure of the formula [4] is contained in an amount of 1 to 90 mol% in all diamine components used for obtaining the component (A) or the component (B). A liquid crystal aligning agent according to item.   The liquid crystal aligning film obtained from the liquid crystal aligning agent of any one of Claims 1-6.   A liquid crystal display device comprising the liquid crystal alignment film according to claim 7.