WO2009154208A1 - Liquid-crystal alignment material, liquid-crystal display element employing same, and novel diamine - Google Patents

Abstract

Provided are a novel diamine, a polyamic acid, and a polyimide which are useful for obtaining a liquid-crystal alignment material giving a liquid-crystal alignment film which has a high voltage retentivity and is less apt to suffer initial charge accumulation therein even when a direct-current voltage is applied to the liquid-crystal cell.  Also provided is a liquid-crystal alignment material. The liquid-crystal alignment material contains at least one of: a polyamic acid obtained by reacting a diamine ingredient comprising a diamine of formula [1] with a tetracarboxylic dianhydride ingredient; and a polyimide obtained by imidizing the polyamic acid. (In formula [1], R represents a C1-25 saturated hydrocarbon group.)

Description

Liquid crystal aligning agent, liquid crystal display element using the same, and novel diamine

The present invention relates to a liquid crystal alignment treatment agent and a liquid crystal alignment film used for a liquid crystal display device, and further relates to a novel diamine useful as a raw material for polyamic acid or polyimide used for the liquid crystal alignment treatment agent.

At present, as a liquid crystal alignment film of a liquid crystal display element, a so-called polyimide type liquid crystal alignment treatment agent (also referred to as a liquid crystal alignment agent) mainly composed of a polyimide precursor such as polyamic acid or a solution of soluble polyimide is applied and baked. A liquid crystal alignment film is mainly used.

The liquid crystal alignment film is used for the purpose of controlling the alignment state of the liquid crystal. However, as the liquid crystal display element becomes higher in definition, the liquid crystal alignment film used has a high voltage holding ratio from the viewpoint of suppressing the decrease in contrast of the liquid crystal display element and reducing the afterimage phenomenon. A characteristic that accumulation of accumulated charges (RDC) is small or that charges accumulated by a DC voltage are quickly relaxed is important.

In the polyimide-based liquid crystal alignment film, a liquid crystal aligning agent containing a tertiary amine having a specific structure in addition to polyamic acid or imide group-containing polyamic acid was used as a short time until the afterimage generated by direct current voltage disappeared. There are known ones (for example, see Patent Document 1) and those using a liquid crystal aligning agent containing a soluble polyimide using a specific diamine having a pyridine skeleton as a raw material (for example, see Patent Document 2).

In addition, in the polyimide-based liquid crystal alignment film, it is assumed that the voltage holding ratio is high and the time until the afterimage generated by the direct current voltage disappears is short, one in the molecule in addition to polyamic acid and its imidized polymer. Liquid crystal alignment containing a very small amount of a compound selected from a compound containing a carboxylic acid group, a compound containing one carboxylic anhydride group in the molecule, and a compound containing one tertiary amino group in the molecule The thing using an agent (for example, refer patent document 3) is known.

However, simply shortening the time until the afterimage disappears has not been sufficient as a countermeasure against the afterimage phenomenon.

JP-A-9-316200 JP-A-10-104633 JP-A-8-76128

In view of the above situation, the present invention provides a liquid crystal alignment treatment agent capable of obtaining a liquid crystal alignment film that has a high voltage holding ratio and is unlikely to cause initial charge accumulation even when a DC voltage is applied to the liquid crystal cell. An object is to provide a diamine, a polyamic acid, and a polyimide useful for obtaining such a liquid crystal aligning agent.

As a result of intensive studies to achieve the above object, the present inventors have completed the present invention. That is, the present invention has the following gist.
1. The liquid-crystal aligning agent containing at least one of the polyamic acid obtained by making the diamine component and the tetracarboxylic dianhydride component containing the diamine of following formula [1] react, or the polyimide which imidated this polyamic acid.

（式中、Ｒは炭素原子数が１～２５の飽和炭化水素基を表す。）
２．　式［１］で表されるジアミンが、ポリアミック酸の合成に使用する全ジアミン成分の２０～１００mol％である、上記１に記載の液晶配向処理剤。
３．　式［１］で表されるジアミンが、２つのアミノ基をメタまたはパラの位置に有するジアミンである、上記１又は２に記載の液晶配向処理剤。
４．　下記式［２］で表されるジアミンを、テトラカルボン酸二無水物成分と反応させるジアミン成分に含む、上記１に記載の液晶配向処理剤。

(In the formula, R represents a saturated hydrocarbon group having 1 to 25 carbon atoms.)
2. 2. The liquid crystal aligning agent according to 1, wherein the diamine represented by the formula [1] is 20 to 100 mol% of the total diamine component used for the synthesis of the polyamic acid.
3. The liquid crystal aligning agent of said 1 or 2 whose diamine represented by Formula [1] is a diamine which has two amino groups in the position of meta or para.
4). The liquid crystal aligning agent of said 1 containing the diamine represented by following formula [2] in the diamine component made to react with a tetracarboxylic dianhydride component.

（式中のＡｒはベンゼン環またはナフタレン環を表し、Ｒ_１は炭素原子数が１～５のアルキレン基であり、Ｒ_２は水素原子又はメチル基である。）
５．　テトラカルボン酸二無水物成分が、脂環式構造又は脂肪族構造を有するテトラカルボン酸二無水物を含むテトラカルボン酸二無水物成分である、上記１～４のいずれかに記載の液晶配向処理剤。
６．　上記１～５のいずれかに記載の液晶配向処理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。
８．　下記式［１－１］のジアミン。

(In the formula, Ar represents a benzene ring or a naphthalene ring, R ₁ represents an alkylene group having 1 to 5 carbon atoms, and R ₂ represents a hydrogen atom or a methyl group.)
5). 5. The liquid crystal alignment treatment according to any one of 1 to 4 above, wherein the tetracarboxylic dianhydride component is a tetracarboxylic dianhydride component including a tetracarboxylic dianhydride having an alicyclic structure or an aliphatic structure. Agent.
6). 6. A liquid crystal alignment film obtained from the liquid crystal alignment treatment agent according to any one of 1 to 5 above.
7). 7. A liquid crystal display device comprising the liquid crystal alignment film as described in 6 above.
8). Diamine of the following formula [1-1].

（式中、Ｒ_３は、炭素原子数が１～５の直鎖状アルキル基である。）
９．　下記式［１－２］のジアミン。

(In the formula, R ₃ is a linear alkyl group having 1 to 5 carbon atoms.)
9. Diamine of the following formula [1-2].

（式中、Ｒ_４は、少なくとも１つの環構造を含む炭素原子数が３～８の飽和炭化水素基である。）
１０．　上記８又は９に記載のジアミンを含むジアミン成分とテトラカルボン酸二無水物成分とを反応させて得られるポリアミック酸。
１１．　上記１０に記載のポリアミック酸をイミド化したポリイミド。

(Wherein R ₄ is a saturated hydrocarbon group having 3 to 8 carbon atoms containing at least one ring structure.)
10. The polyamic acid obtained by making the diamine component containing the diamine of said 8 or 9 and the tetracarboxylic dianhydride component react.
11. A polyimide obtained by imidizing the polyamic acid described in 10 above.

The liquid crystal alignment treatment agent of the present invention can provide a liquid crystal alignment film that has a high voltage holding ratio and is less likely to accumulate charges even when a DC voltage is applied to the liquid crystal cell. By using this liquid crystal alignment film, A liquid crystal panel with favorable characteristics can be manufactured. In addition, the liquid crystal alignment film obtained from the liquid crystal aligning agent of the present invention is less likely to cause defects such as scraping and scratches even in the rubbing process.

By using the novel diamine, polyamic acid, or polyimide of the present invention, an excellent liquid crystal aligning agent as described above can be easily obtained.

Also, the novel diamine of the present invention is easy to synthesize, and by using it as a raw material for polyamic acid, polyimide, etc., the solubility of the resulting polyamic acid or polyimide in a solvent can be enhanced. Since the polyamic acid or polyimide of the present invention is excellent in solubility in a solvent, a uniform coating film can be obtained.

The liquid-crystal aligning agent of this invention contains the polyamic acid obtained by making a diamine component and a tetracarboxylic dianhydride component react, or the polyimide which imidized the amic acid, In this diamine component, a formula It is a liquid crystal aligning agent characterized by containing the diamine represented by [1]. By using this diamine, the obtained liquid crystal alignment film has a high voltage holding ratio, and even if a direct current voltage is applied to the liquid crystal cell, it is possible to make it difficult for charges to accumulate.
<Diamine of Formula [1]>
In the diamine represented by the formula [1], the position of each substituent on the benzene ring is not particularly limited. From the viewpoint of the orientation of the liquid crystal when the liquid crystal alignment film is used, the positional relationship between the two amino groups is preferably meta or para, and from the viewpoint of increasing the solvent solubility of polyamic acid or polyimide, meta is more preferable. . In the case where the positional relationship between the two amino groups is meta, that is, in the case of a 1,3-diaminobenzene structure, the position of the methylene ester is preferably 4 or 5, and in particular, the effect of increasing the nucleophilicity of the amino group From the viewpoint of easy synthesis, the position of 5 is more preferable.

In the diamine represented by the formula [1], R is a saturated hydrocarbon group having 1 to 25 carbon atoms. This saturated hydrocarbon group may be a linear or branched alkyl group and may contain a ring structure. Specific examples of such saturated hydrocarbon groups include methyl groups, ethyl groups, linear alkyl groups from n-propyl groups to n-pentacosyl groups; iso-propyl groups, sec-butyl groups, tert-butyl groups. , Iso-butyl group, 1-ethylpropyl group, 1,1-dimethylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1,1-dimethylbutyl group, 3,3-dimethylbutyl group In addition, a branched alkyl group having up to 25 carbon atoms and branched at any position; a cycloalkyl group typified by a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, etc .; Methyl group, cyclobutylmethyl group, cyclopentylmethyl group, cyclohexylmethyl group, 2-cyclopropylethyl group, -Cyclobutylethyl group, 2-cyclopentylethyl group, 2-cyclohexylethyl group, 2-methylcyclopropyl group, 1-methylcyclohexyl group, 2-methylcyclohexyl group, 4-tert-butylcyclohexyl group, bicyclohexyl group, etc. A group in which an alkyl group and a cycloalkyl group or two or more cycloalkyl groups are combined; bicyclo [2,2,1] heptan-2-yl group, adamantane-1-yl group, adamantane-1-yl-methyl group And a group having a condensed ring.

In the diamine represented by the formula [1], from the viewpoint of the accumulation property of accumulated charge (RDC) when a liquid crystal alignment film is used, those having a relatively small number of R carbon atoms are preferable. For example, R preferably has 1 to 17 carbon atoms, more preferably 1 to 8 carbon atoms. In view of liquid crystal alignment and rubbing resistance, R is preferably a linear alkyl group having a smaller molecular weight. Accordingly, in the diamine represented by the formula [1], specific examples of R that are preferable from the viewpoints of liquid crystal orientation, rubbing resistance, accumulated charge (RDC) accumulation, etc., are methyl, ethyl, and propyl groups. , A butyl group, and a pentyl group are relatively low molecular weight alkyl groups.

On the other hand, when R has a ring structure such as a cycloalkyl group, there is an effect that the solvent solubility of polyamic acid or polyimide becomes higher. Accordingly, in the diamine represented by the formula [1], specific examples of R that are preferable from the viewpoint of solvent solubility of polyamic acid and polyimide, storage property of stored charge (RDC) when used as a liquid crystal alignment film, and the like can be given. , Cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cyclopropylmethyl group, cyclobutylmethyl group, cyclopentylmethyl group, cyclohexylmethyl group, 2-cyclopropylethyl group, 2-cyclobutylethyl group, 2-cyclopentylethyl Group, 2-cyclohexylethyl group, 2-methylcyclopropyl group, 1-methylcyclohexyl group, 2-methylcyclohexyl group and the like.

The method for synthesizing the diamine represented by the formula [1] is not particularly limited. For example, a dinitro compound represented by the following formula [3] is synthesized, and the nitro group is reduced by a usual method. It can be synthesized by a method of converting to an amino group.

（上記式中のＲは、式［１］のＲと同じである）
　式［３］で表されるジニトロ化合物は、下記反応式のように、ピリジンやトリエチルアミンなどの塩基存在下で、目的のジアミンの置換基の位置に対応するジニトロベンジルアルコールに、目的のジアミンのＲに対応するカルボン酸クロリドまたは酸二無水物を反応させることにより合成することができる。

(R in the above formula is the same as R in formula [1])
In the presence of a base such as pyridine or triethylamine, the dinitro compound represented by the formula [3] is converted to the dinitrobenzyl alcohol corresponding to the position of the target diamine substituent in the presence of R of the target diamine. Can be synthesized by reacting a carboxylic acid chloride or acid dianhydride corresponding to.

（上記式中のＲは、式［１］のＲと同じである）
　前記した式［１］のジアミンの好ましい置換基の位置に対応するジニトロベンジルアルコールとしては、２，４－ジニトロベンジルアルコール、３，５－ジニトロベンジルアルコール、２，５－ジニトロベンジルアルコール等がある。

(R in the above formula is the same as R in formula [1])
Examples of the dinitrobenzyl alcohol corresponding to the preferred substituent position of the diamine of the formula [1] include 2,4-dinitrobenzyl alcohol, 3,5-dinitrobenzyl alcohol, and 2,5-dinitrobenzyl alcohol.

Of the diamines represented by the formula [1], the diamine of the following formula [1-1] or the diamine of the following formula [1-2] is a novel diamine particularly useful for the liquid crystal aligning agent of the present invention. It is.

（式中、Ｒ_３は、炭素原子数が１～５の直鎖状アルキル基である。）

(In the formula, R ₃ is a linear alkyl group having 1 to 5 carbon atoms.)

（式中、Ｒ_４は、少なくとも１つの環構造を含む炭素原子数が３～８の飽和炭化水素基である。）
　上記式［１－１］又は［１－２］のジアミンは、その他の式［１］で表されるジアミンと同様に前記した方法によって合成することができる。
　上記式［１－１］又は［１－２］のジアミンにおいて、２つのアミノ基の位置関係はメタまたはパラが好ましく、また、ポリアミック酸やポリイミドの溶媒溶解性を高めるという観点では、メタがより好ましい。

(Wherein R ₄ is a saturated hydrocarbon group having 3 to 8 carbon atoms containing at least one ring structure.)
The diamine of the above formula [1-1] or [1-2] can be synthesized by the method described above in the same manner as the other diamines represented by the formula [1].
In the diamine of the above formula [1-1] or [1-2], the positional relationship between the two amino groups is preferably meta or para, and from the viewpoint of increasing the solvent solubility of polyamic acid or polyimide, meta is more preferred. preferable.

Hereinafter, preferred specific examples of the diamine represented by the formula [1-1] are listed, but the present invention is not limited thereto.

　上記式［４］～［１８］のジアミンは、ベンゼン環上の置換基の位置によって、下記［ａ］、［ｂ］、及び［ｃ］の形態に分類できるが、前述したように、［ｂ］の形態が特に好ましく、具体的には式［５］、式［８］、式［１１］、式［１４］、又は式［１７］のジアミンが特に好ましい。

The diamines of the above formulas [4] to [18] can be classified into the following forms [a], [b], and [c] depending on the position of the substituent on the benzene ring. The diamine of formula [5], formula [8], formula [11], formula [14], or formula [17] is particularly preferred.

（上記式［ａ］～［ｃ］におけるＲは、式［１］のＲと同じである）
　以下に、式［１－２］で表されるジアミンの中でも特に好ましいものとして、上記［ｂ］の形態である具体例を示すが、本発明はこれに限定されるものではない。

(R in the above formulas [a] to [c] is the same as R in formula [1])
Specific examples of the diamine represented by the formula [1-2] are shown below as specific examples of the above-mentioned form [b], but the present invention is not limited thereto.

<Diamine component>
The diamine represented by the formula [1] can be reacted with a tetracarboxylic dianhydride to obtain a polyamic acid, and imidized with the polyamic acid to be a polyimide.
In the present invention, the diamine component used when synthesizing the polyamic acid may be only the diamine represented by the formula [1], or may be a combination of one or more selected from other diamines.

By including the diamine represented by the formula [1] as the diamine component, the solvent solubility of the resulting polyamic acid and a polyimide obtained by imidizing this polyamic acid can be enhanced. Furthermore, the liquid crystal alignment film obtained from the liquid crystal aligning agent containing this polyamic acid or polyimide has a high voltage holding ratio, and even if a direct current voltage is applied to a liquid crystal cell, it becomes difficult to accumulate an electric charge. In order to obtain such characteristics, the diamine represented by the formula [1] is preferably 20 to 100 mol%, more preferably 40 to 100 mol% of the total diamine component used for the synthesis of the polyamic acid. In particular, it is 50 to 100 mol%.

In the above diamine component, the diamine used in combination with the diamine represented by the formula [1] is not particularly limited. Specific examples of such diamines are as follows.

Examples of alicyclic diamines include 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, 4,4′-diaminodicyclohexylmethane, 4,4′-diamino-3,3′-dimethyldicyclohexylamine, isophorone diamine Etc.

Examples of aromatic diamines include o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 2,4-diaminotoluene, 2,5-diaminotoluene, 3,5-diaminotoluene, 1,4-diamino- 2-methoxybenzene, 2,5-diamino-p-xylene, 1,3-diamino-4-chlorobenzene, 3,5-diaminobenzoic acid, 1,4-diamino-2,5-dichlorobenzene, 4,4 ′ -Diamino-1,2-diphenylethane, 4,4'-diamino-2,2'-dimethylbibenzyl, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 2,2'-diaminostilbene, 4,4'-diamy Stilbene, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 4,4'- Diaminobenzophenone, 1,3-bis (3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 3,5-bis (4- Aminophenoxy) benzoic acid, 4,4'-bis (4-aminophenoxy) bibenzyl, 2,2-bis [(4-aminophenoxy) methyl] propane, 2,2-bis [4- (4-aminophenoxy) Phenyl] hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, 1,1-bis (4-aminophenyl) cyclohexane, α, α′-bis (4- Aminophenyl) -1,4-diisopropylbenzene, 9,9-bis (4-aminophenyl) fluorene, 2,2-bis (3-aminophenyl) hexafluoropropane, 2,2-bis (4-aminophenyl) Hexafluoropropane, 4,4'-diaminodiphenylamine, 2,4-diaminodiphenylamine, 1,8-diaminonaphthalene, 1,5-diaminonaphthalene, 1,5-diaminoanthraquinone, 1,3-diaminopyrene, 1,6 -Diaminopyrene, 1,8-diaminopyrene, 2,7-diaminofluorene, 1,3-bis (4-amino Enyl) tetramethyldisiloxane, benzidine, 2,2′-dimethylbenzidine, 1,2-bis (4-aminophenyl) ethane, 1,3-bis (4-aminophenyl) propane, 1,4-bis (4 -Aminophenyl) butane, 1,5-bis (4-aminophenyl) pentane, 1,6-bis (4-aminophenyl) hexane, 1,7-bis (4-aminophenyl) heptane, 1,8-bis (4-aminophenyl) octane, 1,9-bis (4-aminophenyl) nonane, 1,10-bis (4-aminophenyl) decane, 1,3-bis (4-aminophenoxy) propane, 1,4 -Bis (4-aminophenoxy) butane, 1,5-bis (4-aminophenoxy) pentane, 1,6-bis (4-aminophenoxy) hexane, 1,7-bis (4- Aminophenoxy) heptane, 1,8-bis (4-aminophenoxy) octane, 1,9-bis (4-aminophenoxy) nonane, 1,10-bis (4-aminophenoxy) decane, di (4-aminophenyl) ) Propane-1,3-dioate, di (4-aminophenyl) butane-1,4-dioate, di (4-aminophenyl) pentane-1,5-dioate, di (4-aminophenyl) hexane-1, 6-dioate, di (4-aminophenyl) heptane-1,7-dioate, di (4-aminophenyl) octane-1,8-dioate, di (4-aminophenyl) nonane-1,9-dioate, di (4-aminophenyl) decane-1,10-dioate, 1,3-bis [4- (4-aminophenoxy) phenoxy] propane, 1,4-bi [4- (4-aminophenoxy) phenoxy] butane, 1,5-bis [4- (4-aminophenoxy) phenoxy] pentane, 1,6-bis [4- (4-aminophenoxy) phenoxy] hexane, , 7-bis [4- (4-aminophenoxy) phenoxy] heptane, 1,8-bis [4- (4-aminophenoxy) phenoxy] octane, 1,9-bis [4- (4-aminophenoxy) phenoxy Nonane, 1,10-bis [4- (4-aminophenoxy) phenoxy] decane, and the like.

Examples of heterocyclic diamines include 2,6-diaminopyridine, 2,4-diaminopyridine, 2,4-diamino-1,3,5-triazine, 2,7-diaminodibenzofuran, 3,6-diaminocarbazole 2,4-diamino-6-isopropyl-1,3,5-triazine, 2,5-bis (4-aminophenyl) -1,3,4-oxadiazole and the like.

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

Examples of aromatic-aliphatic diamines include diamines represented by the following formula [2].

　ここで式中のＡｒはベンゼン環またはナフタレン環を表し、Ｒ_１は炭素原子数が１～５のアルキレン基であり、Ｒ_２は水素原子又はメチル基である。
式［２］で表されるジアミンにおいて、Ａｒがベンゼン環であり、Ｒ_２が水素原子であるのが好ましい。

Here, Ar in the formula represents a benzene ring or a naphthalene ring, R ₁ represents an alkylene group having 1 to 5 carbon atoms, and R ₂ represents a hydrogen atom or a methyl group.
In the diamine represented by the formula [2], Ar is preferably a benzene ring and R ₂ is preferably a hydrogen atom.

Specific examples of the diamine represented by the formula [2] include 3-aminobenzylamine, 4-aminobenzylamine, 3-amino-N-methylbenzylamine, 4-amino-N-methylbenzylamine, 3-amino Phenethylamine, 4-aminophenethylamine, 3-amino-N-methylphenethylamine, 4-amino-N-methylphenethylamine, 3- (3-aminopropyl) aniline, 4- (3-aminopropyl) aniline, 3- (3- Methylaminopropyl) aniline, 4- (3-methylaminopropyl) aniline, 3- (4-aminobutyl) aniline, 4- (4-aminobutyl) aniline, 3- (4-methylaminobutyl) aniline, 4- (4-Methylaminobutyl) aniline, 3- (5-aminopentyl) aniline, 4- (5-amino) Nthyl) aniline, 3- (5-methylaminopentyl) aniline, 4- (5-methylaminopentyl) aniline, 2- (6-aminonaphthyl) methylamine, 3- (6-aminonaphthyl) methylamine, 2- Examples include (6-aminonaphthyl) ethylamine and 3- (6-aminonaphthyl) ethylamine, but are not limited thereto.

When the diamine represented by the formula [2] is used in combination with the diamine represented by the formula [1], the solubility of the resulting polymer in an organic solvent is further improved, and when used as a liquid crystal alignment film. It is preferable because of excellent liquid crystal alignment. Further, such a combination can enhance the effect of increasing the pretilt angle of the liquid crystal by diamine, which will be described later, so that the amount of use can be reduced when obtaining the same pretilt angle. Since the diamine capable of increasing the pretilt angle of the liquid crystal tends to deteriorate the printability of the liquid crystal aligning agent when the amount of use increases, if the amount of the diamine used can be reduced, Improvement in printability is expected.

The preferable content of the diamine represented by the formula [2] is 10 to 50 mol%, more preferably 20 to 40 mol% of the entire diamine component. When the diamine represented by the formula [2] is contained, the preferable content of the diamine represented by the formula [1] is 20 to 90 mol%, more preferably 30 to 80 mol% of the entire diamine component.

As a diamine that can increase the pretilt angle of the liquid crystal when it is used as a liquid crystal alignment film by including it in a diamine component when synthesizing a polyamic acid, a long chain alkyl group, a perfluoroalkyl group, an aromatic cyclic group, Diamines having an aliphatic cyclic group, a combination of these, a steroid skeleton group, and the like are known. These diamines can also be used in the present invention in combination with the diamine represented by the formula [1]. Although the specific example of the diamine which has such a substituent is given to the following, this invention is not limited to these. In the structures exemplified below, j represents an integer of 5 to 20, and k represents an integer of 1 to 20.

　上記のジアミンの内、式［１９］のジアミンは液晶配向性に優れるため好ましい。式［２６］～［３３］のジアミンは、プレチルト角の発現能が非常に高いため、ＯＣＢ（Optically Compensated Bend）液晶用配向膜（以下、ＯＣＢ用配向膜とする）、垂直配向モード液晶用配向膜（以下、ＶＡ用配向膜とする）に好適に用いられる。
　例えば、ＴＮ液晶用配向膜（プレチルト角が３～５°）では式［１９］のジアミンの含有量をジアミン成分全体の１０～３０mol％とし、ＯＣＢ用配向膜、あるいはＶＡ用配向膜（プレチルト角が１０～９０°）では、式［２６］～［３３］のジアミンの含有量をジアミン成分全体の５～４０mol％とするとよいが、これに限定されない。

Among the above diamines, the diamine of the formula [19] is preferable because of excellent liquid crystal alignment. Since the diamines represented by the formulas [26] to [33] have a very high pretilt angle developing ability, they are OCB (Optically Compensated Bend) liquid crystal alignment films (hereinafter referred to as OCB alignment films) and vertical alignment mode liquid crystal alignments. It is suitably used for a film (hereinafter referred to as an alignment film for VA).
For example, in the alignment film for TN liquid crystal (pretilt angle 3 to 5 °), the content of the diamine of formula [19] is 10 to 30 mol% of the total diamine component, and the alignment film for OCB or VA (pretilt angle) Is 10 to 90 °), the diamine content of the formulas [26] to [33] may be 5 to 40 mol% of the total diamine component, but is not limited thereto.

<Tetracarboxylic dianhydride component>
In the polyamic acid or polyimide of the present invention, the tetracarboxylic dianhydride component to be reacted with the diamine component described above is not particularly limited, and may be one type of tetracarboxylic dianhydride, or two or more types. These tetracarboxylic dianhydrides may be used in combination.

In the liquid crystal aligning agent of the present invention, a tetracarboxylic dianhydride to be reacted with the diamine component is used as a tetracarboxylic acid dianhydride to be reacted with the diamine component in order to further improve the voltage holding ratio of the liquid crystal cell. It is preferable to use a carboxylic dianhydride. 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-cyclohexylsuccinic dianhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic dianhydride, [4 (2,5-dioxotetrahydrofuran-3-yl) -1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic acid anhydride], 1,2,3,4-butanetetracarboxylic dianhydride Bicyclo [3,3,0] octane-2,4,6,8-tetracarboxylic dianhydride, 3,3 ′, 4,4′-dicyclohexyltetracarboxylic dianhydride, 2,3,5- Tricarboxycyclopentylacetic 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-teto Carboxylic acid 4,5: 11,12-dianhydride, and the like. Of these, 1,2,3,4-cyclobutanetetracarboxylic dianhydride is particularly preferred because an alignment film having excellent liquid crystal orientation can be obtained.

Furthermore, when an aromatic tetracarboxylic dianhydride is used in combination, the liquid crystal orientation can be improved and the stored charge in the liquid crystal cell can be released quickly. Aromatic tetracarboxylic dianhydrides include 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 And 2,3,6,7-naphthalenetetracarboxylic dianhydride and the like. Of these, pyromellitic dianhydride is particularly preferable.

The tetracarboxylic dianhydride having an alicyclic structure or an aliphatic structure is considered in consideration of the balance of each characteristic such as solubility of the obtained polyamic acid or polyimide, orientation of liquid crystal, voltage holding ratio, accumulated charge, etc. The aromatic tetracarboxylic dianhydride is used in a molar ratio of the former / the latter of preferably 90/10 to 50/50, more preferably 80/20 to 60/40.

<Polymerization reaction>
In the present invention, the polymerization reaction method of the tetracarboxylic dianhydride component and the diamine component is not particularly limited. Generally, by mixing in an organic solvent, a polymerization reaction can be performed to obtain a polyamic acid, and a polyimide can be obtained by dehydrating and ring-closing this polyamic acid.

As a method of mixing the tetracarboxylic dianhydride component and the diamine component in an organic solvent, a 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. are mentioned. When the tetracarboxylic dianhydride component or the diamine component is composed of a plurality of types of compounds, the plurality of types of components may be preliminarily mixed or may be individually polymerized sequentially.
The temperature for the polymerization reaction of the tetracarboxylic dianhydride component and the diamine component in an organic solvent is usually 0 to 150 ° C, preferably 5 to 100 ° C, more preferably 10 to 80 ° C. When the temperature is higher, the polymerization reaction is completed earlier, but when it is too high, a high molecular weight polymer may not be obtained.

In addition, the polymerization reaction can be performed at any concentration, but if the total concentration of the tetracarboxylic dianhydride component and the diamine component is too low, it becomes difficult to obtain a high molecular weight polymer, and if the concentration is too high, Since the viscosity of the reaction solution becomes too high and uniform stirring becomes difficult, it is preferably 1 to 50% by mass, more preferably 5 to 30% by mass. The initial stage of the polymerization reaction may be performed at a high concentration, and then an organic solvent may be added.

The organic solvent used in the polymerization reaction is not particularly limited as long as the generated polyamic acid can be dissolved. Specific examples thereof include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, 3-methoxy-N, N-dimethylpropanamide, N-methylcaprolactam, dimethyl sulfoxide, Examples include tetramethylurea, pyridine, dimethylsulfone, hexamethylsulfoxide, γ-butyrolactone, 1,3-dimethylimidazolidinone. These may be used alone or in combination. Furthermore, even if the solvent does not dissolve the polyamic acid, it 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 generated polyamic acid, it is preferable to use a dehydrated and dried organic solvent as much as possible.

The ratio of the tetracarboxylic dianhydride component and the diamine component used for the polymerization reaction of the polyamic acid is preferably 1: 0.8 to 1: 1.2 in molar ratio, and this molar ratio is close to 1: 1. The molecular weight of the polyamic acid obtained increases. By controlling the molecular weight of this polyamic acid, the molecular weight of the polyimide obtained after imidation can be adjusted.

The molecular weight of the polyamic acid or polyimide of the present invention is not particularly limited, but when included in the liquid crystal alignment treatment agent, from the viewpoint of the strength of the resulting coating film and ease of handling as the liquid crystal alignment treatment agent, the weight average The molecular weight is preferably 2,000 to 200,000, more preferably 5,000 to 50,000.

<Synthesis of polyimide>
The polyimide of the present invention is a polyimide obtained by imidizing the above polyamic acid. The imidization of the polyamic acid can be performed by stirring in an organic solvent for 1 to 100 hours in the presence of a basic catalyst and an acid anhydride.
Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine and the like. Of these, pyridine is preferable because it has an appropriate basicity for proceeding with the reaction. Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, pyromellitic anhydride, and the like. Among them, acetic anhydride is preferable because the obtained polyimide can be easily purified after imidization. As an organic solvent, the solvent used at the time of the polyamic acid polymerization reaction mentioned above can be used.

The imidation ratio of polyimide can be controlled by adjusting the amount of catalyst, reaction temperature, and reaction time. The amount of the basic catalyst at this time is preferably 0.2 to 10 times mol, more preferably 0.5 to 5 times mol of the amic acid group. Further, the amount of the acid anhydride is preferably 1 to 30 times mol, more preferably 1 to 10 times mol of the amic acid group. The reaction temperature is preferably −20 to 250 ° C., more preferably 0 to 180 ° C.

Although the imidation rate of the polyimide of the present invention is not particularly limited, the imidation rate is 40% or more when contained in the liquid crystal alignment treatment agent because a liquid crystal alignment film having a higher voltage holding ratio is obtained. It is preferably 60% or more, more preferably 80% or more.
Since the added catalyst or the like remains in the polyimide solution thus obtained, when used as a liquid crystal alignment treatment agent, it is preferable to recover and wash the polyimide before use.

The polyimide can be recovered by putting the solution after imidization into a poor solvent that is being stirred and precipitating the polyimide, followed by filtration. Examples of the poor solvent at this time include methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, and benzene. The recovered polyimide can also be washed with this poor solvent. The polyimide recovered and washed in this way can be powdered by drying at normal temperature or under reduced pressure at room temperature or by heating.
Such an operation can also be performed on the polyamic acid. For example, when it is not desired to include the solvent used for the polymerization of polyamic acid in the liquid crystal aligning agent, or when it is desired to remove unreacted monomer components and impurities in the reaction solution, the above precipitation recovery and purification are performed. Just do it.

<Liquid crystal alignment agent>
The liquid-crystal aligning agent of this invention is a coating liquid containing at least 1 type of the polymer chosen from the polyamic acid and polyimide which were obtained as mentioned above.
When the production example is given, the reaction solution of the polyamic acid or polyimide described above may be used as it is or diluted, and the precipitate recovered from the reaction solution may be redissolved in an organic solvent. In the dilution and re-dissolution process, adjustment of the solvent composition for controlling the coating property to the substrate, addition of an additive for improving the properties of the coating film, and the like can be performed. Furthermore, you may mix with the solution of the polyimide of the structure different from the above, the solution of a polyamic acid, and you may add another resin component.

The organic solvent used in the above-described dilution and re-dissolution process is not particularly limited as long as it can dissolve the contained polymer. Specific examples include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, 3-methoxy-N, N-dimethylpropanamide, N-methylcaprolactam, 2-pyrrolidone. N-ethylpyrrolidone, N-vinylpyrrolidone, dimethyl sulfoxide, tetramethyl urea, dimethyl sulfone, hexamethyl sulfoxide, γ-butyrolactone, 1,3-dimethyl-imidazolidinone and the like. Of these, N-methyl-2-pyrrolidone, 1,3-dimethylimidazolidinone, and γ-butyrolactone are preferably used. You may use these 1 type or in mixture of 2 or more types.

Solvents added to control the coating property of the liquid crystal aligning agent on the substrate include ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, ethyl carbitol acetate, ethylene glycol, 1-methoxy-2-propanol, 1 -Ethoxy-2-propanol, 1-butoxy-2-propanol, 1-phenoxy-2-propanol, diethylene glycol diethyl ether, propylene glycol monoacetate, propylene glycol diacetate, dipropylene glycol monomethyl ether, propylene glycol-1-monomethyl ether -2-acetate, propylene glycol-1-monoethyl ether-2-acetate, dipropylene glycol, 2- (2-ethoxypropoxy) propanol, Acid methyl ester, lactic acid ethyl ester, lactic acid n- propyl ester, lactate n- butyl ester, and the like lactic isoamyl ester. These solvents include solvents that cannot dissolve polyamic acid or polyimide alone, but can be mixed with the liquid crystal aligning agent of the present invention as long as the resin does not precipitate. In particular, it is known that the coating film uniformity is improved upon application to a substrate by appropriately mixing a solvent having a low surface tension, and it is also suitably used in the liquid crystal aligning agent of the present invention. Among these, butyl cellosolve, ethyl carbitol, dipropylene glycol monomethyl ether, or diethylene glycol diethyl ether is particularly preferable from the viewpoint of solubility of polyimide.

Additives for improving the properties of the coating include 3-aminopropylmethyldiethoxysilane, 3-phenylaminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, (aminoethylaminomethyl) phenethyltrimethoxysilane And silane coupling agents such as By adding these silane coupling agents, it is possible to improve the adhesion of the coating film to the substrate, but adding too much may cause aggregation of resin components such as polyamic acid and polyimide. The silane coupling agent is preferably added in an amount of 0.5 to 10% by mass, more preferably 1 to 5% by mass with respect to a resin component such as polyimide.

The solid content concentration of the liquid crystal alignment treatment agent of the present invention can be appropriately changed depending on the thickness of the liquid crystal alignment film to be formed, but is preferably 1 to 10% by mass. If it is less than 1% by mass, it is difficult to form a uniform and defect-free coating film, and if it exceeds 10% by mass, the storage stability of the solution may be deteriorated. Further, the concentration of the polyamic acid or polyimide of the present invention in this solid content is not particularly limited, but is preferably 1% by mass or more, more preferably 3% by mass or more from the viewpoint of the characteristics of the obtained liquid crystal alignment film. In particular, it is 5% by mass or more.
The liquid crystal alignment treatment agent obtained as described above is preferably filtered before being applied to the substrate.

<Liquid crystal display element>
The liquid-crystal aligning agent of this invention can be used as a liquid-crystal aligning film for rubbing by apply | coating to a board | substrate, drying, and baking and making it into a coating film, and rubbing the coating-film surface. It is also used as a liquid crystal alignment film for VA and a photo alignment film that are not rubbed.
In this case, the substrate to be used is not particularly limited as long as it is a highly transparent substrate. A glass substrate, an acrylic substrate, a plastic substrate such as a polycarbonate substrate, or the like can be used, and an ITO electrode for driving a liquid crystal is formed. It is preferable to use a new substrate from the viewpoint of simplification of the process. Further, in the reflection type liquid crystal display element, an opaque material such as a silicon wafer can be used as long as the substrate is only on one side, and in this case, a material that reflects light such as aluminum can be used.

Examples of the method for applying the liquid crystal aligning agent include spin coating, printing, and ink-jet methods. From the viewpoint of productivity, the flexographic printing method is widely used industrially, and the liquid crystal aligning treatment of the present invention. It is also preferably used in agents.
The drying process after applying the liquid crystal alignment treatment agent is not necessarily required, but if the time from application to baking is not constant for each substrate, or if baking is not performed immediately after application, the drying process is performed. It is preferable to include. The drying is not particularly limited as long as the solvent is evaporated to such an extent that the shape of the coating film is not deformed by transporting the substrate or the like. A specific example is a method of drying on a hot plate at 50 to 150 ° C., preferably 80 to 120 ° C. for 0.5 to 30 minutes, preferably 1 to 5 minutes.

The substrate coated with the liquid crystal aligning agent can be baked at an arbitrary temperature of 100 to 350 ° C., preferably 150 to 300 ° C., more preferably 180 to 250 ° C. When an amic acid group is present in the liquid crystal aligning agent, the conversion rate from the amic acid to the imide varies depending on the firing temperature, but the liquid crystal aligning agent of the present invention does not necessarily need to be 100% imidized. .
If the thickness of the coating film after baking 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, so it is preferably 10 to 200 nm, more preferably 50 to 100 nm.
An existing rubbing apparatus can be used for rubbing the coating surface formed on the substrate as described above. Examples of the material of the rubbing cloth at this time include cotton, rayon, and nylon.

A substrate with a liquid crystal alignment film obtained by the above method can be used as a liquid crystal display element by preparing a liquid crystal cell by a known method. As an example of liquid crystal cell production, a pair of substrates on which a liquid crystal alignment film is formed is preferably an arbitrary rubbing direction of 0 to 270 ° with a spacer of preferably 1 to 30 μm, more preferably 2 to 10 μm. A method is generally used in which the angle is set to be fixed, the periphery is fixed with a sealant, and liquid crystal is injected and sealed. The method for enclosing the liquid crystal is not particularly limited, and examples thereof include a vacuum method of injecting liquid crystal after reducing the pressure inside the produced liquid crystal cell, and a dropping method of sealing after dropping the liquid crystal.
The liquid crystal display elements thus obtained include various types such as TN liquid crystal display elements, STN liquid crystal display elements, TFT liquid crystal display elements, OCB liquid crystal display elements, lateral electric field type liquid crystal display elements, and VA liquid crystal display elements. It is suitably used for a display element by the above method.

The present invention will be described in more detail with reference to the following examples, but the present invention should not be construed as being limited thereto.
Example 1
Synthesis of 3,5-diaminobenzyl acetate;

　３，５－ジニトロベンジルアルコール　２０．０ｇ（０．１００ｍｏｌ）をテトラヒドロフラン　２００ｍｌに溶解させ、無水酢酸　３０．６ｇ（０．３００ｍｏｌ）、ピリジン２．４ｇ（０．０３０ｍｏｌ）を加え、窒素雰囲気下で６時間還流させた。

Dissolve 20.0 g (0.100 mol) of 3,5-dinitrobenzyl alcohol in 200 ml of tetrahydrofuran, add 30.6 g (0.300 mol) of acetic anhydride and 2.4 g (0.030 mol) of pyridine, and add 6 g under nitrogen atmosphere. Reflux for hours.

The disappearance of the raw material spot was confirmed by TLC (Tin-Layer Chromatography), extracted with ethyl acetate, washed with pure water to remove acetic anhydride and acetic acid, washed with brine, and then dried with anhydrous magnesium sulfate. . Recrystallization was performed using a mixed solvent of ethanol and isopropyl alcohol to obtain milky white crystals (22 g (0.092 mol) of the compound of the formula [ii], yield 92%).
1H-NMR (d-DMSO, δppm): 8.80 (1H, t), 8.67 (2H, d), 5.33 (2H, s), 2.13 (3H, s)
1H-NMR means a nuclear magnetic resonance spectrum of an intramolecular hydrogen atom.
20.0 g (0.083 mol) of the compound of formula [ii] was dissolved in 200 ml of 1,4-dioxane, sufficiently degassed and purged with nitrogen, added with 2.0 g of platinum oxide, and again sufficiently degassed. A hydrogen gas atmosphere was used and the reaction was allowed to proceed for 24 hours at room temperature. After completion of the reaction, platinum oxide was removed with celite, the solvent was removed, and the residue was dissolved with methanol, activated carbon treatment and recrystallization (solvent: ethanol), and a milky white solid (12 g of the compound of formula [iii] ( 0.067 mol), yield 81%).
1H-NMR (CDCl ₃ , δ ppm): 6.11 (2H, d), 5.98 (1H, t), 4.92 (2H, s), 3.60 (4H, Br), 2.13 (3H, s)
The abbreviations of the compounds used for the synthesis of polyamic acid and polyimide are as follows.

<Tetracarboxylic dianhydride>
CBDA: 1,2,3,4-cyclobutanetetracarboxylic dianhydride <diamine>
DABAc: 3,5-diaminobenzyl acetate DABBu: 3,5-diaminobenzyl butyrate DABCPr: 3,5-diaminobenzyl cyclopropanecarboxylate DABCPE: 3,5-diaminobenzyl cyclopentanecarboxylate DABCPP: 3,5-diaminobenzyl 3-cyclopentylpropanoate DABCHx: 3,5-diaminobenzyl cyclohexanecarboxylate C14DAB: 4-tetradecyloxy-1,3-diaminobenzene 3-ABA: 3-aminobenzylamine <organic solvent>
NMP: N-methyl-2-pyrrolidone γ-BL: γ-butyrolactone BC: Butyl cellosolve DPM: Dipropylene glycol monomethyl ether <Measurement of molecular weight>
The molecular weight of the polyimide obtained by the polymerization reaction was measured with a GPC (normal temperature gel permeation chromatography) apparatus, and the number average molecular weight and 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 additives, lithium bromide-hydrate (LiBr • H2O) is 30 mmol / L, phosphoric acid / anhydrous crystal (o-phosphoric acid) is 30 mmol / L, tetrahydrofuran (THF ) Is 10ml / L)
Flow rate: 1.0 ml / min Standard sample for calibration curve: TSK standard polyethylene oxide (molecular weight: about 900,000, 150,000, 100,000, 30,000) manufactured by Tosoh Corporation and polyethylene glycol (molecular weight: about 12,000, 4,000, 1,000) manufactured by Polymer Laboratories .

<Measurement of imidization ratio>
The imidation ratio of the polyimide obtained by the polymerization reaction was determined by dissolving the polyimide in d6-DMSO (dimethyl sulfoxide-d6), measuring 1H-NMR, and measuring the ratio of amidic acid groups remaining without imidization. Was calculated from the ratio of the integrated values of proton peaks.

<Production of liquid crystal cell>
With respect to the liquid crystal alignment treatment agents prepared in Examples 2-7, the liquid crystal alignment treatment agents prepared in Examples 13-24, and the liquid crystal alignment treatment agents prepared in Comparative Examples 1-2, liquid crystal cells were produced as follows. did.
A liquid crystal alignment treatment agent is spin-coated on a glass substrate with a transparent electrode, dried on an 80 ° C. hot plate for 5 minutes, and then baked on a 210 ° C. hot plate for 10 minutes to form a coating film having a thickness of 70 nm. I let you. This coating film 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. Prepare two substrates with a liquid crystal alignment film, spray a 6μm spacer on the surface of one liquid crystal alignment film, print a sealant on it, and face the other substrate with the liquid crystal alignment film surface After laminating so that the rubbing direction was perpendicular, the sealing agent was cured to produce an empty cell. Liquid crystal MLC-2003 (manufactured by Merck Japan) 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.

A method for measuring physical properties and evaluating characteristics of each produced liquid crystal cell is described below.
Tables 1 and 2 summarize the results of the composition of each liquid crystal alignment treatment agent in Examples 2 to 7 and Comparative Examples 1 and 2, measurement of physical properties of each liquid crystal alignment film, and evaluation of characteristics. Indicated. Tables 3 and 4 collectively show the results of the composition of each liquid crystal alignment treatment agent, the measurement of physical properties of each liquid crystal alignment film, and the evaluation of characteristics in Examples 13 to 24.

<Rubbing resistance evaluation>
As a rubbing resistance verification test, rubbing was performed under the condition that the indentation amount was changed to 0.5 mm, and the film surface was observed with a high-focus laser microscope. Evaluation was performed as follows.
○: Scraping and rubbing scratches are not observed.
Δ: Scraping and rubbing scratches are observed.
X: A film | membrane peels or a rubbing damage | wound is observed visually.
<Pretilt angle measurement>
The prepared twisted nematic liquid crystal cell was heated at 105 ° C. for 5 minutes, and then the pretilt angle and the voltage holding ratio were measured. The pretilt angle was measured using a crystal rotation method.
<Measurement of voltage holding ratio>
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 16.67 ms, and determining how much the voltage can be held. As calculated. The voltage holding ratio was measured using a VHR-1 voltage holding ratio measuring device manufactured by Toyo Technica.

<Estimation of accumulated charge (RDC)>
A direct current voltage was applied from 0 V to 1.0 V at a 0.1 V interval at a temperature of 23 ° C. to the produced twisted nematic liquid crystal cell, and a flicker amplitude level at each voltage was measured to prepare a calibration curve. After grounding for 5 minutes, an AC voltage of 3.0 V and a DC voltage of 5.0 V were applied, the flicker amplitude level after 1 hour was measured, and RDC was estimated by comparing with a calibration curve prepared in advance.
(This RDC estimation method is called a flicker reference method.)

(Example 2)
Using 5.00 g (0.025 mol) of CBDA as the tetracarboxylic dianhydride component and 4.69 g (0.026 mol) of DABAc as the diamine component, the polyamic acid was reacted in NMP 38.73 g at room temperature for 16 hours. A solution (PAA-1) was obtained.
10.0 g of polyamic acid solution (PAA-1) was diluted with 23.3 g of NMP and 10.0 g of BC to obtain a solution having a solid content of 6% by mass, NMP of 64% by mass, and BC of 30% by mass. A liquid crystal alignment treatment agent was obtained. Using this coating solution, a liquid crystal cell was prepared according to the procedure described above, and the physical properties were measured and the characteristics were evaluated as described above.

(Example 3)
To 20 g of the polyamic acid solution (PAA-1), 46.67 g of NMP was added for dilution, and 3.29 g of acetic anhydride and 1.40 g of pyridine were added and reacted at 40 ° C. for 3 hours to imidize. The reaction solution was cooled to about room temperature and then poured into 250 ml of methanol to recover the precipitated solid. The solid was washed several times with methanol and then dried under reduced pressure at 100 ° C. to obtain a white powder of polyimide (SPI-1). The number average molecular weight of this polyimide was 12,259, and the weight average molecular weight was 35,793. The imidation ratio was 80%.
18 g of NMP was added to 2 g of the obtained polyimide (SPI-1), and the mixture was stirred at 50 ° C. for 20 hours. The polyimide was completely dissolved at the end of stirring. Further, 8.0 g of NMP and 12.0 g of BC were added to this solution, and the mixture was stirred at 50 ° C. for 20 hours to obtain a solution containing 5% by mass of polyimide, 65% by mass of NMP, and 30% by mass of BC. Got. Using this coating solution, a liquid crystal cell was produced in the same manner as in Example 2, and physical properties were measured and characteristics were evaluated.

Example 4
As tetracarboxylic dianhydride component, 6.09 g (0.031 mol) of CBDA, 4.00 g (0.022 mol) of DABAc and 3.04 g (0.01 mol) of C14DAB as diamine components, 74.5 g of NMP The mixture was reacted at room temperature for 16 hours to obtain a polyamic acid solution (PAA-2).
10.0 g of polyamic acid solution (PAA-2) was diluted with 23.3 g of NMP and 10.0 g of BC to obtain a solution having a solid content of 6% by mass, NMP of 64% by mass, and BC of 30% by mass. A liquid crystal alignment treatment agent was obtained. Using this coating solution, a liquid crystal cell was produced in the same manner as in Example 2, and physical properties were measured and characteristics were evaluated.

(Example 5)
116.67 g of NMP was added to 50 g of polyamic acid solution (PAA-2) for dilution, and 7.39 g of acetic anhydride and 3.15 g of pyridine were added and reacted at 50 ° C. for 3 hours to imidize.
The reaction solution was cooled to about room temperature and then poured into 1.25 L of methanol to recover the precipitated solid. The solid was washed several times with methanol and then dried under reduced pressure at 100 ° C. to obtain a white powder of polyimide (SPI-2). The number average molecular weight of this polyimide was 16,321, and the weight average molecular weight was 39,857. Moreover, the imidation ratio was 85%.
18 g of γ-BL was added to 2 g of polyimide (SPI-2) and stirred at 50 ° C. for 20 hours. The polyimide was completely dissolved at the end of stirring. Further, γ-BL 8.0 g, BC 6.0 g, and DPM 6.0 g were added to this solution, and the mixture was stirred at 50 ° C. for 20 hours. Polyimide was 5 mass%, γ-BL was 65 mass%, DPM was 15 mass%, and BC was The liquid crystal aligning agent of the present invention was obtained in a 15% by mass solution. Using this coating solution, a liquid crystal cell was produced in the same manner as in Example 2, and physical properties were measured and characteristics were evaluated.

(Example 6)
As a tetracarboxylic dianhydride component, 13.53 g (0.073 mol) of CBDA, as a diamine component, 4.00 g (0.022 mol) of DABAc, 3.67 g (0.030 mol) of 3-ABA, and C14DAB 7.12 g (0.022 mol) was used and reacted in NMP 116.0 g at room temperature for 16 hours to obtain a polyamic acid solution (PAA-3).
10.0 g of polyamic acid solution (PAA-3) was diluted with 23.3 g of NMP and 10.0 g of BC to obtain a solution having a solid content of 6% by mass, NMP of 64% by mass and BC of 30% by mass. A liquid crystal alignment treatment agent was obtained. Using this coating solution, a liquid crystal cell was produced in the same manner as in Example 2, and physical properties were measured and characteristics were evaluated.

(Example 7)
To 100 g of polyamic acid solution (PAA-3), 233.33 g of NMP was added for dilution, 15.66 g of acetic anhydride and 6.67 g of pyridine were added, and the mixture was reacted at 70 ° C. for 3 hours to imidize.
The reaction solution was cooled to about room temperature and then poured into 1.25 L of methanol to recover the precipitated solid. The solid was washed several times with methanol and then dried under reduced pressure at 100 ° C. to obtain a light brown powder of polyimide (SPI-3). The number average molecular weight of this polyimide was 18,649, and the weight average molecular weight was 41,774. The imidation ratio was 94%.
18 g of γ-BL was added to 2 g of polyimide (SPI-3), and the mixture was stirred at 50 ° C. for 20 hours. The polyimide was completely dissolved at the end of stirring. Further, γ-BL 8.0 g, BC 6.0 g, and DPM 6.0 g were added to this solution, and the mixture was stirred at 50 ° C. for 20 hours. Polyimide was 5 mass%, γ-BL was 65 mass%, DPM was 15 mass%, and BC was The liquid crystal aligning agent of the present invention was obtained in a 15% by mass solution. Using this coating solution, a liquid crystal cell was produced in the same manner as in Example 2, and physical properties were measured and characteristics were evaluated.

(Comparative Example 1)
As the tetracarboxylic dianhydride component, 12.5 g (0.064 mol) of CBDA, 5.56 g (0.046 mol) of 3-ABA and 6.25 g (0.020 mol) of C14DAB were used as the diamine component, and NMP97 The reaction was carried out in 20 g at room temperature for 16 hours to obtain a polyamic acid solution (PAA-4).
Dilute 10.0 g of polyamic acid (PAA-4) with 23.3 g of NMP and 10.0 g of BC to obtain a solution having a solid content of 6% by mass, NMP of 64% by mass and BC of 30% by mass. A liquid crystal aligning agent was obtained. Using this coating solution, a liquid crystal cell was produced in the same manner as in Example 2, and physical properties were measured and characteristics were evaluated.

(Comparative Example 2)
116.67 g of NMP was added to 50 g of polyamic acid solution (PAA-4) for dilution, and 7.39 g of acetic anhydride and 3.15 g of pyridine were added and reacted at 70 ° C. for 3 hours for imidization. Gelled inside.
Again, 116.67 g of NMP was added to 50 g of polyamic acid solution (PAA-4) for dilution, 7.39 g of acetic anhydride and 3.15 g of pyridine were added, and the imidation reaction temperature was set to 50 ° C.
The reaction solution was cooled to about room temperature and then poured into 250 ml of methanol to recover the precipitated solid. The solid was washed several times with methanol and then dried under reduced pressure at 100 ° C. to obtain a white powder of polyimide (SPI-4). The number average molecular weight of this polyimide was 16,338, and the weight average molecular weight was 39,865. The imidation ratio was 80%.
9 g of γ-BL was added to 1 g of polyimide (SPI-4) and stirred at 50 ° C. for 20 hours. The polyimide was completely dissolved at the end of stirring. Further, 4.0 g of γ-BL, 3.0 g of BC, and 3.0 g of DPM were added to this solution, and the mixture was stirred at 50 ° C. for 20 hours. The polyimide was 5 mass%, γ-BL was 65 mass%, DPM was 15 mass%, and BC was The liquid crystal aligning agent used as a comparison object was obtained as a 15% by mass solution. Using this coating solution, a liquid crystal cell was produced in the same manner as in Example 2, and physical properties were measured and characteristics were evaluated.

＊；光学的フリッカー参照法により、直流電圧(DC)をとめた直後のRDC

*: RDC immediately after the DC voltage (DC) is stopped by the optical flicker reference method.

(Example 8)
Synthesis of 3,5-diaminobenzyl butyrate;

　３，５－ジニトロベンジルアルコール　２０．０ｇ（０．１００ｍｏｌ）、ピリジン２．４ｇ（０．０３０ｍｏｌ）を脱水ＤＭＦ　２００ｍｌに溶解させ、氷浴中でブチリルクロリド　１１．８０ｇ（０．１１０ｍｏｌ）を加え、室温で６時間攪拌させた。
　ＴＬＣで原料スポットが消失したのを確認し、反応溶液を冷やした純水中に注ぎ、析出した固体をろ過し、メタノールと水で洗浄を行った。その後、エタノールとイソプロピルアルコールの混合溶媒を用いて再結晶を行い、乳白色の結晶（式［iv］の化合物２４ｇ（０．０８２ｍｏｌ）、収率８２％）を得た。
1H-NMR(d-DMSO,δppm):8.80(t,1H),8.67(d,2H),5.35(s,2H),2.45(m,2H),1.65(m,2H),0.93-0.89(m,3H)
　式［iv］の化合物２４．０ｇ（０．０８２ｍｏｌ）を１，４－ジオキサン２００ｍｌに溶解させ、十分脱気と窒素置換を行い、白金／カーボン２．４ｇを加え、再び十分脱気を行った上で水素ガス雰囲気にし、室温で２４時間反応させた。反応終了後、白金／カーボンをセライトろ過で取り除き、更に活性炭処理をした上で溶媒除去を行い、茶色の粘体（式［v］の化合物１２ｇ（０．０５８ｍｏｌ）、収率７１％）を得た。
1H-NMR(CDCl₃,δppm):6.11(d,2H),5.99(t,1H),4.94(s,2H),3.62(br,4H),2.30-1.98(m,2H),1.61-1.50(m,2H),0.91-0.86(m,3H)

Dissolve 20.0 g (0.100 mol) of 3,5-dinitrobenzyl alcohol and 2.4 g (0.030 mol) of pyridine in 200 ml of dehydrated DMF, and add 11.80 g (0.110 mol) of butyryl chloride in an ice bath. And stirred at room temperature for 6 hours.
After confirming the disappearance of the raw material spots by TLC, the reaction solution was poured into cooled pure water, the precipitated solid was filtered, and washed with methanol and water. Thereafter, recrystallization was performed using a mixed solvent of ethanol and isopropyl alcohol to obtain milky white crystals (24 g (0.082 mol) of the compound of the formula [iv], yield 82%).
1H-NMR (d-DMSO, δppm): 8.80 (t, 1H), 8.67 (d, 2H), 5.35 (s, 2H), 2.45 (m, 2H), 1.65 (m, 2H), 0.93-0.89 ( m, 3H)
24.0 g (0.082 mol) of the compound of the formula [iv] was dissolved in 200 ml of 1,4-dioxane, sufficiently deaerated and purged with nitrogen, added with 2.4 g of platinum / carbon, and sufficiently deaerated again. A hydrogen gas atmosphere was formed above and the reaction was allowed to proceed at room temperature for 24 hours. After completion of the reaction, platinum / carbon was removed by celite filtration, and after further treatment with activated carbon, the solvent was removed to obtain a brown viscous body (12 g (0.058 mol) of the compound of formula [v], yield 71%). .
1H-NMR (CDCl ₃ , δ ppm): 6.11 (d, 2H), 5.99 (t, 1H), 4.94 (s, 2H), 3.62 (br, 4H), 2.30-1.98 (m, 2H), 1.61-1.50 (m, 2H), 0.91-0.86 (m, 3H)

Example 9
Synthesis of 3,5-diaminobenzyl cyclopropanecarboxylate;

　３，５－ジニトロベンジルアルコール　２０．０ｇ（０．１００ｍｏｌ）、シクロプロパンカルボニルクロリド　１５．７ｍｌを、テトラヒドロフラン　２００ｍｌに溶解させた。これにピリジン１０．０ｍｌを滴下し、室温で２４時間攪拌した。反応終了後、純水５０ｍｌを加え１時間攪拌した。これに酢酸エチルを加えて溶媒抽出を行い、取り出した有機層を１Ｎ塩酸、飽和重曹水、飽和食塩水で順次洗浄した。洗浄後の有機層に無水硫酸マグネシウムを加えて脱水し、これを濾過した後、ロータリーエバポレーターを用いて濾液から溶媒を留去した。溶媒留去後の残渣を、イソプロピルアルコールを用いて再結晶し、ジニトロ化合物（式［vi］の化合物２４ｇ（０．０９０ｍｏｌ）、収率９０％）を得た。
1H-NMR(CDCl₃,δppm):8.80(t,1H),8.67(d,2H),5.33(s,2H),1.80-1.73 (m,1H),0.98-0.92(m,4H)
　式［vi］の化合物２０．０ｇ（０．０７５ｍｏｌ）、酸化白金２．０ｇを、１．４－ジオキサン２５０ｍｌに加え、水素雰囲気下室温で攪拌した。反応終了後、酸化白金をセライトろ過で取り除き、ロータリーエバポレーターを用いて溶媒留去を行った。溶媒留去後の残渣をメタノール２００ｍｌに溶解させ、活性炭を２．０ｇ加え室温で攪拌した。活性炭をセライトろ過により除去し、ロータリーエバポレーターを用いて溶媒を留去し、残渣を酢酸エチル／ヘキサン＝１／５を用いて再結晶し、乳白色固体（式［vii］の化合物１２．０ｇ（０．５８２ｍｏｌ）、収率７８％)を得た。
1H-NMR(CDCl₃,δppm):6.11(d,2H),5.98(t,1H),4.92(s,2H),3.60(br,4H)，１.78-1.65 (m,1H),0.98-0.92(m,4H)

20.0 g (0.100 mol) of 3,5-dinitrobenzyl alcohol and 15.7 ml of cyclopropanecarbonyl chloride were dissolved in 200 ml of tetrahydrofuran. To this, 10.0 ml of pyridine was added dropwise and stirred at room temperature for 24 hours. After completion of the reaction, 50 ml of pure water was added and stirred for 1 hour. Ethyl acetate was added thereto for solvent extraction, and the extracted organic layer was washed successively with 1N hydrochloric acid, saturated aqueous sodium hydrogen carbonate, and saturated brine. The organic layer after washing was dehydrated by adding anhydrous magnesium sulfate, filtered, and then the solvent was distilled off from the filtrate using a rotary evaporator. The residue after evaporation of the solvent was recrystallized using isopropyl alcohol to obtain a dinitro compound (24 g (0.090 mol) of the compound of formula [vi], yield 90%).
1H-NMR (CDCl ₃ , δppm): 8.80 (t, 1H), 8.67 (d, 2H), 5.33 (s, 2H), 1.80-1.73 (m, 1H), 0.98-0.92 (m, 4H)
20.0 g (0.075 mol) of the compound of the formula [vi] and 2.0 g of platinum oxide were added to 250 ml of 1.4-dioxane and stirred at room temperature in a hydrogen atmosphere. After completion of the reaction, platinum oxide was removed by celite filtration, and the solvent was distilled off using a rotary evaporator. The residue after evaporation of the solvent was dissolved in 200 ml of methanol, and 2.0 g of activated carbon was added and stirred at room temperature. Activated charcoal was removed by Celite filtration, the solvent was distilled off using a rotary evaporator, the residue was recrystallized using ethyl acetate / hexane = 1/5, and milky white solid (12.0 g of compound of formula [vii] (0 582 mol), yield 78%).
1H-NMR (CDCl ₃ , δ ppm): 6.11 (d, 2H), 5.98 (t, 1H), 4.92 (s, 2H), 3.60 (br, 4H), 1.78-1.65 (m, 1H), 0.98 -0.92 (m, 4H)

(Example 10)
Synthesis of 3,5-diaminobenzyl cyclopentanecarboxylate;

　３，５－ジニトロベンジルアルコール　２０．０ｇ（０．１００ｍｏｌ）、シクロペンタンカルボニルクロリド　１２．９ｍｌを、テトラヒドロフラン２００ｍｌに溶解させた。これにピリジン９．０ｍｌを滴下し、室温で２２時間攪拌した。反応終了後、純水５０ｍｌを加え１時間攪拌した。これに酢酸エチルを加えて溶媒抽出を行い、取り出した有機層を１Ｎ塩酸、飽和重曹水、飽和食塩水で順次洗浄した。洗浄後の有機層に無水硫酸マグネシウムを加えて脱水し、これを濾過した後、ロータリーエバポレーターを用いて濾液から溶媒を留去した。溶媒留去後の残渣を、イソプロピルアルコールを用いて再結晶し、ジニトロ化合物（式［viii］の化合物２４ｇ（０．０８２ｍｏｌ）、収率８２％）を得た。
1H-NMR(CDCl₃,δppm):9.01(t,1H),8.56-8.54(m,2H),5.30(d,2H),2.91-2.83(m,1H),2.03-1.58(m,8H)
　式［viii］の化合物２４．０ｇ（０．０８２ｍｏｌ）、白金／カーボン２．５ｇを、メタノール２５０ｍｌに加え、水素雰囲気下室温で攪拌した。反応終了後、白金／カーボンをセライトろ過で取り除き、ロータリーエバポレーターを用いて溶媒留去を行った。溶媒留去後の残渣をメタノール２００ｍｌに溶解させ、活性炭を２．０ｇ加え室温で攪拌した。活性炭をセライトろ過により除去し、ロータリーエバポレーターを用いて溶媒を留去し、更に減圧下乾燥して、褐色液体（式［ix］の化合物１９．３ｇ（０．０８２ｍｏｌ）、収率９６％)を得た。
1H-NMR(CDCl₃,δppm):6.10(d,2H),5.97(t,1H),4.92(s,2H),3.52(br,4H),2.77(m,1H),1.95-1.51(m,8H)

20.0 g (0.100 mol) of 3,5-dinitrobenzyl alcohol and 12.9 ml of cyclopentanecarbonyl chloride were dissolved in 200 ml of tetrahydrofuran. To this, 9.0 ml of pyridine was added dropwise and stirred at room temperature for 22 hours. After completion of the reaction, 50 ml of pure water was added and stirred for 1 hour. Ethyl acetate was added thereto for solvent extraction, and the extracted organic layer was washed successively with 1N hydrochloric acid, saturated aqueous sodium hydrogen carbonate, and saturated brine. The organic layer after washing was dehydrated by adding anhydrous magnesium sulfate, filtered, and then the solvent was distilled off from the filtrate using a rotary evaporator. The residue after evaporation of the solvent was recrystallized using isopropyl alcohol to obtain a dinitro compound (24 g (0.082 mol) of the compound of the formula [viii], yield 82%).
_{1H-NMR (CDCl 3, δppm} ): 9.01 (t, 1H), 8.56-8.54 (m, 2H), 5.30 (d, 2H), 2.91-2.83 (m, 1H), 2.03-1.58 (m, 8H)
24.0 g (0.082 mol) of the compound of the formula [viii] and 2.5 g of platinum / carbon were added to 250 ml of methanol and stirred at room temperature in a hydrogen atmosphere. After completion of the reaction, platinum / carbon was removed by Celite filtration, and the solvent was distilled off using a rotary evaporator. The residue after evaporation of the solvent was dissolved in 200 ml of methanol, and 2.0 g of activated carbon was added and stirred at room temperature. Activated carbon was removed by celite filtration, the solvent was distilled off using a rotary evaporator, and the residue was further dried under reduced pressure to obtain a brown liquid (19.3 g (0.082 mol) of the compound of formula [ix], yield 96%). Obtained.
_{1H-NMR (CDCl 3, δppm} ): 6.10 (d, 2H), 5.97 (t, 1H), 4.92 (s, 2H), 3.52 (br, 4H), 2.77 (m, 1H), 1.95-1.51 (m , 8H)

(Example 11)
Synthesis of 3,5-diaminobenzyl 3-cyclopentylpropanoate;

　３，５－ジニトロベンジルアルコール　２３．１ｇ（０．１１７ｍｏｌ）、３－シクロペンチルプロピオニルクロリド　１９．３ｍｌを、テトラヒドロフラン２５０ｍｌに溶解させた。これにピリジン１０．３ｍｌを滴下し、室温で１６時間攪拌した。反応終了後、純水５０ｍｌを加え１時間攪拌した。これに酢酸エチルを加えて溶媒抽出を行い、取り出した有機層を１Ｎ塩酸、飽和重曹水、飽和食塩水で順次洗浄した。洗浄後の有機層に無水硫酸マグネシウムを加えて脱水し、これを濾過した後、ロータリーエバポレーターを用いて濾液から溶媒を留去した。溶媒留去後の残渣を、ヘキサン／酢酸エチル＝３／１を用いて再結晶し、ジニトロ化合物（式［x］の化合物２９．８ｇ（０．０９２ｍｏｌ）、収率７９％）を得た。
1H-NMR(CDCl₃,δppm): 9.02(t,1H),8.57-8.54(m,2H),5.30(s,2H),2.49-2.43(m,2H),1.83-1.45(m,9H),1.18-1.04(m,2H)
　式［x］の化合物２９．８ｇ（０．０９２ｍｏｌ）、白金／カーボン３．１を、メタノール３００ｍｌに加え、水素雰囲気下室温で攪拌した。反応終了後、白金／カーボンをセライトろ過で取り除き、ロータリーエバポレーターを用いて溶媒留去を行った。溶媒留去後の残渣を酢酸エチル／ヘキサン＝１／６を用いて再結晶し、薄茶色固体（式［xi］の化合物２１．６ｇ（０．０８２ｍｏｌ）、収率８９％）を得た。
1H-NMR(CDCl₃,δppm):6.11(d,2H),5.99(t,1H),4.92(s,2H),3.60(br,4H),2.39-2.34(m,2H),1.81-1.45(m,9H),1.17-1.20(m,2H)

3,5-dinitrobenzyl alcohol (23.1 g, 0.117 mol) and 3-cyclopentylpropionyl chloride (19.3 ml) were dissolved in tetrahydrofuran (250 ml). To this, 10.3 ml of pyridine was added dropwise and stirred at room temperature for 16 hours. After completion of the reaction, 50 ml of pure water was added and stirred for 1 hour. Ethyl acetate was added thereto for solvent extraction, and the extracted organic layer was washed successively with 1N hydrochloric acid, saturated aqueous sodium hydrogen carbonate, and saturated brine. The organic layer after washing was dehydrated by adding anhydrous magnesium sulfate, filtered, and then the solvent was distilled off from the filtrate using a rotary evaporator. The residue after the solvent was distilled off was recrystallized using hexane / ethyl acetate = 3/1 to obtain a dinitro compound (29.8 g (0.092 mol) of the compound of formula [x], yield 79%).
1H-NMR (CDCl ₃ , δ ppm): 9.02 (t, 1H), 8.57-8.54 (m, 2H), 5.30 (s, 2H), 2.49-2.43 (m, 2H), 1.83-1.45 (m, 9H) 1.18-1.04 (m, 2H)
29.8 g (0.092 mol) of the compound of the formula [x] and platinum / carbon 3.1 were added to 300 ml of methanol and stirred at room temperature in a hydrogen atmosphere. After completion of the reaction, platinum / carbon was removed by Celite filtration, and the solvent was distilled off using a rotary evaporator. The residue after evaporation of the solvent was recrystallized using ethyl acetate / hexane = 1/6 to obtain a light brown solid (21.6 g (0.082 mol) of the compound of formula [xi], yield 89%).
1H-NMR (CDCl ₃ , δ ppm): 6.11 (d, 2H), 5.99 (t, 1H), 4.92 (s, 2H), 3.60 (br, 4H), 2.39-2.34 (m, 2H), 1.81-1.45 (m, 9H), 1.17-1.20 (m, 2H)

Example 12
Synthesis of 3,5-diaminobenzyl cyclohexanecarboxylate;

　３，５－ジニトロベンジルアルコール　２０．１ｇ（０．１０１ｍｏｌ）、シクロヘキサンカルボニルクロリド　１４．５ｍｌを、テトラヒドロフラン２００ｍｌに溶解させた。これにピリジン９．０ｍｌを滴下し、室温で２３時間攪拌した。反応終了後、純水５０ｍｌを加え１時間攪拌した。これに酢酸エチルを加えて溶媒抽出を行い、取り出した有機層を１Ｎ塩酸、飽和重曹水、飽和食塩水で順次洗浄した。洗浄後の有機層に無水硫酸マグネシウムを加えて脱水し、これを濾過した後、ロータリーエバポレーターを用いて濾液から溶媒を留去した。溶媒留去後の残渣を、イソプロピルアルコールを用いて再結晶し、ジニトロ化合物（式［xii］の化合物２５.０ｇ（０．０８１ｍｏｌ）、収率８１％）を得た。
1H-NMR(CDCl₃,δppm):9.01(t,1H),8.55-8.53(m,2H),5.30(d,2H),2.44(tt,1H),2.02-1.92(m,2H),1.83-1.64(m,3H),1.55-1.18(m,5H)
　式［xii］の化合物２４．８ｇ（０．０８１ｍｏｌ）、白金／カーボン２．５ｇを、メタノール２５０ｍｌに加え、水素雰囲気下室温で攪拌した。反応終了後、白金／カーボンをセライトろ過で取り除き、ロータリーエバポレーターを用いて溶媒留去を行った。溶媒留去後の残渣をメタノール２００ｍｌに溶解させ、活性炭を２．０ｇ加え室温で攪拌した。活性炭をセライトろ過により除去し、ロータリーエバポレーターを用いて溶媒を留去し、更に減圧下乾燥して、褐色液体（式［xiii］の化合物１９．３ｇ（０．０７８ｍｏｌ）、収率９６％)を得た。
1H-NMR(CDCl₃,δppm):6.10(d,2H),5.98(t,1H),4.92(s,2H),3.61(br,4H),2.34(tt,1H),1.98-1.89(m,2H),1.81-1.14(m,8H)

20.1 g (0.101 mol) of 3,5-dinitrobenzyl alcohol and 14.5 ml of cyclohexanecarbonyl chloride were dissolved in 200 ml of tetrahydrofuran. To this, 9.0 ml of pyridine was added dropwise and stirred at room temperature for 23 hours. After completion of the reaction, 50 ml of pure water was added and stirred for 1 hour. Ethyl acetate was added thereto for solvent extraction, and the extracted organic layer was washed successively with 1N hydrochloric acid, saturated aqueous sodium hydrogen carbonate, and saturated brine. The organic layer after washing was dehydrated by adding anhydrous magnesium sulfate, filtered, and then the solvent was distilled off from the filtrate using a rotary evaporator. The residue after evaporation of the solvent was recrystallized using isopropyl alcohol to obtain a dinitro compound (25.0 g (0.081 mol) of the compound of the formula [xii], yield 81%).
1H-NMR (CDCl ₃ , δ ppm): 9.01 (t, 1H), 8.55-8.53 (m, 2H), 5.30 (d, 2H), 2.44 (tt, 1H), 2.02-1.92 (m, 2H), 1.83 -1.64 (m, 3H), 1.55-1.18 (m, 5H)
24.8 g (0.081 mol) of the compound of the formula [xii] and 2.5 g of platinum / carbon were added to 250 ml of methanol and stirred at room temperature in a hydrogen atmosphere. After completion of the reaction, platinum / carbon was removed by Celite filtration, and the solvent was distilled off using a rotary evaporator. The residue after evaporation of the solvent was dissolved in 200 ml of methanol, and 2.0 g of activated carbon was added and stirred at room temperature. The activated carbon was removed by Celite filtration, the solvent was distilled off using a rotary evaporator, and the residue was further dried under reduced pressure to obtain a brown liquid (19.3 g (0.078 mol) of the compound of the formula [xiii], yield 96%). Obtained.
_{1H-NMR (CDCl 3, δppm} ): 6.10 (d, 2H), 5.98 (t, 1H), 4.92 (s, 2H), 3.61 (br, 4H), 2.34 (tt, 1H), 1.98-1.89 (m , 2H), 1.81-1.14 (m, 8H)

(Example 13)
7.64 g (0.039 mol) of CBDA as a tetracarboxylic dianhydride component, 2.50 g (0.012 mol) of DABBu, 1.95 g (0.016 mol) of 3-ABA, and 3.14 g of C14DAB as a diamine component. Using 84 g (0.012 mol), the reaction was allowed to proceed in 63.79 g of NMP at room temperature for 16 hours to obtain a polyamic acid solution (PAA-5).
10.0 g of polyamic acid solution (PAA-5) was diluted with 23.3 g of NMP and 10.0 g of BC to obtain a solution containing 6% by mass of polyamic acid, 64% by mass of NMP and 30% by mass of BC. A liquid crystal alignment treatment agent was obtained. Using this coating solution, a liquid crystal cell was produced in the same manner as in Example 2, and physical properties were measured and characteristics were evaluated.

(Example 14)
116.67 g of NMP was added to 50 g of polyamic acid solution (PAA-5) for dilution, 7.83 g of acetic anhydride and 3.33 g of pyridine were added, and the mixture was reacted at 70 ° C. for 3 hours to imidize. The reaction solution was cooled to about room temperature and then poured into 1.25 L of methanol to recover the precipitated solid. The solid was washed several times with methanol and then dried under reduced pressure at 100 ° C. to obtain a light brown powder of polyimide (SPI-5). The number average molecular weight of this polyimide was 16,358, and the weight average molecular weight was 38,735. Moreover, the imidation ratio was 90%.
18 g of γ-BL was added to 2 g of polyimide (SPI-5), and the mixture was stirred at 50 ° C. for 20 hours. The polyimide was completely dissolved at the end of stirring. Further, γ-BL 8.0 g, BC 6.0 g, and DPM 6.0 g were added to this solution, and the mixture was stirred at 50 ° C. for 20 hours. Polyimide was 5 mass%, γ-BL was 65 mass%, DPM was 15 mass%, and BC was The liquid crystal aligning agent of the present invention was obtained in a 15% by mass solution. Using this coating solution, a liquid crystal cell was produced in the same manner as in Example 2, and physical properties were measured and characteristics were evaluated.

(Example 15)
Using 5.00 g (0.025 mol) of CBDA as the tetracarboxylic dianhydride component and 5.32 g (0.026 mol) of DABCPr as the diamine component, the polyamic acid was reacted in NMP 41.32 g at room temperature for 16 hours. A solution (PAA-6) was obtained.
10.0 g of polyamic acid solution (PAA-6) was diluted with 23.3 g of NMP and 10.0 g of BC to obtain a solution containing 6% by mass of polyamic acid, 64% by mass of NMP and 30% by mass of BC. A liquid crystal alignment treatment agent was obtained. Using this coating solution, a liquid crystal cell was produced in the same manner as in Example 2, and physical properties were measured and characteristics were evaluated.

(Example 16)
To 20 g of the polyamic acid solution (PAA-6), 46.67 g of NMP was added for dilution, 3.06 g of acetic anhydride and 1.31 g of pyridine were added, and the mixture was reacted at 40 ° C. for 3 hours to imidize. The reaction solution was cooled to about room temperature and then poured into 250 ml of methanol to recover the precipitated solid. The solid was washed several times with methanol and then dried under reduced pressure at 100 ° C. to obtain a white powder of polyimide (SPI-6). The number average molecular weight of this polyimide was 13,329, and the weight average molecular weight was 33,233. The imidation ratio was 81%.
To 2.00 g of the obtained polyimide (SPI-6), 18.0 g of γ-BL was added and stirred at 50 ° C. for 20 hours. The polyimide was completely dissolved at the end of stirring. Further, 8.0 g of γ-BL, 6.00 g of BC and 6.00 g of DPM were added to this solution, and the mixture was stirred for 20 hours at 50 ° C., 5% by mass of polyimide, 65% by mass of γ-BL, 15% by mass of DPM, and BC The liquid crystal aligning agent of the present invention was obtained in a 15% by mass solution. Using this coating solution, a liquid crystal cell was produced in the same manner as in Example 2, and physical properties were measured and characteristics were evaluated.

(Example 17)
As the tetracarboxylic dianhydride component, 5.52 g (0.028 mol) of CBDA, as the diamine component, 1.79 g (0.009 mol) of DABCPr, 1.42 g (0.011 mol) of 3-ABA, and C14DAB Using 2.79 g (0.009 mol), the reaction was conducted in 46.1 g of NMP at room temperature for 16 hours to obtain a polyamic acid solution (PAA-7).
A polyamic acid solution (PAA-7) 10.0 g was diluted with 23.3 g of NMP and 10.0 g of BC to obtain a solution containing 6% by mass of polyamic acid, 64% by mass of NMP and 30% by mass of BC. A liquid crystal alignment treatment agent was obtained. Using this coating solution, a liquid crystal cell was produced in the same manner as in Example 2, and physical properties were measured and characteristics were evaluated.

(Example 18)
90.0 g of NMP was added to 40.0 g of a polyamic acid solution (PAA-7) for dilution, 6.02 g of acetic anhydride and 2.49 g of pyridine were added, and the mixture was reacted at 60 ° C. for 3 hours to imidize. The reaction solution was cooled to about room temperature and then poured into 500 ml of methanol, and the precipitated solid was recovered. The solid was washed several times with methanol and then dried under reduced pressure at 100 ° C. to obtain a white brown powder of polyimide (SPI-7). The number average molecular weight of this polyimide was 17,430, and the weight average molecular weight was 48,532. Moreover, the imidation ratio was 90%.
12.00 g of γ-BL was added to 2.00 g of this polyimide (SPI-7), and the mixture was stirred at 50 ° C. for 20 hours. The polyimide was completely dissolved at the end of stirring. Further, γ-BL 8.00 g, BC 6.00 g, and DPM 6.00 g were added to this solution, and the mixture was stirred at 50 ° C. for 20 hours. Polyimide was 5 mass%, γ-BL was 65 mass%, DPM was 15 mass%, and BC was The liquid crystal aligning agent of the present invention was obtained in a 15% by mass solution. Using this coating solution, a liquid crystal cell was produced in the same manner as in Example 2, and physical properties were measured and characteristics were evaluated.

(Example 19)
As a tetracarboxylic dianhydride component, 5.71 g (0.029 mol) of CBDA, 2.11 g (0.009 mol) of DABCPE, 1.47 g (0.012 mol) of 3-ABA, and C14DAB as a diamine component Using 2.88 g (0.009 mol), the reaction was conducted in 48.7 g of NMP at room temperature for 16 hours to obtain a polyamic acid solution (PAA-8).
10.0 g of polyamic acid solution (PAA-8) was diluted with 23.3 g of NMP and 10.0 g of BC to obtain a solution containing 6% by mass of polyamic acid, 64% by mass of NMP and 30% by mass of BC. A liquid crystal alignment treatment agent was obtained. Using this coating solution, a liquid crystal cell was produced in the same manner as in Example 2, and physical properties were measured and characteristics were evaluated.

(Example 20)
90.0 g of NMP was added to 40.0 g of a polyamic acid solution (PAA-8) for dilution, and 5.98 g of acetic anhydride and 2.57 g of pyridine were added and reacted at 60 ° C. for 3 hours to imidize. The reaction solution was cooled to about room temperature and then poured into 500 ml of methanol, and the precipitated solid was recovered. The solid was washed several times with methanol and then dried under reduced pressure at 100 ° C. to obtain a white brown powder of polyimide (SPI-8). The number average molecular weight of this polyimide was 14,757, and the weight average molecular weight was 36,865. Moreover, the imidation ratio was 90%.
To 2.00 g of this polyimide (SPI-8), 18.0 g of γ-BL was added and stirred at 50 ° C. for 20 hours. The polyimide was completely dissolved at the end of stirring. Further, γ-BL 8.00 g, BC 6.00 g, and DPM 6.00 g were added to this solution, and the mixture was stirred at 50 ° C. for 20 hours. Polyimide was 5 mass%, γ-BL was 65 mass%, DPM was 15 mass%, and BC was The liquid crystal aligning agent of the present invention was obtained in a 15% by mass solution. Using this coating solution, a liquid crystal cell was produced in the same manner as in Example 2, and physical properties were measured and characteristics were evaluated.

(Example 21)
As tetracarboxylic dianhydride component, 5.71 g (0.029 mol) of CBDA, 2.36 g (0.009 mol) of DABCPP, 1.47 g (0.012 mol) of 3-ABA, and C14DAB as diamine components Using 2.88 g (0.009 mol), the reaction was conducted in 48.7 g of NMP at room temperature for 16 hours to obtain a polyamic acid solution (PAA-9).
10.0 g of polyamic acid solution (PAA-9) was diluted with 23.3 g of NMP and 10.0 g of BC to obtain a solution containing 6% by mass of polyamic acid, 64% by mass of NMP and 30% by mass of BC. A liquid crystal alignment treatment agent was obtained. Using this coating solution, a liquid crystal cell was produced in the same manner as in Example 2, and physical properties were measured and characteristics were evaluated.

(Example 22)
90.0 g of NMP was added to 40.0 g of a polyamic acid solution (PAA-9) for dilution, and 5.86 g of acetic anhydride and 2.51 g of pyridine were added and reacted at 60 ° C. for 3 hours to imidize. The reaction solution was cooled to about room temperature and then poured into 500 ml of methanol, and the precipitated solid was recovered. The solid was washed several times with methanol and then dried under reduced pressure at 100 ° C. to obtain a white brown powder of polyimide (SPI-9). The number average molecular weight of this polyimide was 14,900, and the weight average molecular weight was 35,161. Moreover, the imidation ratio was 91%.
To 2.00 g of this polyimide (SPI-9), 18.0 g of γ-BL was added and stirred at 50 ° C. for 20 hours. The polyimide was completely dissolved at the end of stirring. Further, γ-BL 8.00 g, BC 6.00 g, and DPM 6.00 g were added to this solution, and the mixture was stirred at 50 ° C. for 20 hours. Polyimide was 5 mass%, γ-BL was 65 mass%, DPM was 15 mass%, and BC was The liquid crystal aligning agent of the present invention was obtained in a 15% by mass solution. Using this coating solution, a liquid crystal cell was produced in the same manner as in Example 2, and physical properties were measured and characteristics were evaluated.

(Example 23)
As a tetracarboxylic dianhydride component, 5.71 g (0.029 mol) of CBDA, as a diamine component, 2.23 g (0.009 mol) of DABCHx, 1.47 g (0.012 mol) of 3-ABA, and C14DAB 2.88 g (0.009 mol) was used and reacted in 49.2 g of NMP at room temperature for 16 hours to obtain a polyamic acid solution (PAA-10).
10.0 g of polyamic acid solution (PAA-10) was diluted with 23.3 g of NMP and 10.0 g of BC to obtain a solution containing 6% by mass of polyamic acid, 64% by mass of NMP and 30% by mass of BC. A liquid crystal alignment treatment agent was obtained. Using this coating solution, a liquid crystal cell was produced in the same manner as in Example 2, and physical properties were measured and characteristics were evaluated.

(Example 24)
90.0 g of NMP was added to 40.0 g of a polyamic acid solution (PAA-10) for dilution, and 5.92 g of acetic anhydride and 2.54 g of pyridine were added and reacted at 60 ° C. for 3 hours to imidize. The reaction solution was cooled to about room temperature and then poured into 500 ml of methanol, and the precipitated solid was recovered. The solid was washed several times with methanol and then dried under reduced pressure at 100 ° C. to obtain a white brown powder of polyimide (SPI-10). The number average molecular weight of this polyimide was 15,864, and the weight average molecular weight was 41,355. Moreover, the imidation ratio was 88%.
To 2.00 g of this polyimide (SPI-10), 18.0 g of γ-BL was added and stirred at 50 ° C. for 20 hours. The polyimide was completely dissolved at the end of stirring. Further, γ-BL 8.00 g, BC 6.00 g, and DPM 6.00 g were added to this solution, and the mixture was stirred at 50 ° C. for 20 hours. Polyimide was 5 mass%, γ-BL was 65 mass%, DPM was 15 mass%, and BC was The liquid crystal aligning agent of the present invention was obtained in a 15% by mass solution. Using this coating solution, a liquid crystal cell was produced in the same manner as in Example 2, and physical properties were measured and characteristics were evaluated.

＊；光学的フリッカー参照法により、直流電圧（ＤＣ）をとめた直後のＲＤＣ

*: RDC immediately after stopping DC voltage (DC) by optical flicker reference method

From the comparison between Examples 2, 4, 6, 13, 15, 17, 19, 21, and 23 and Comparative Example 1, in the liquid crystal aligning agent containing polyamic acid, part or all of the diamine component is represented by the formula [ 1], the voltage holding ratio of the liquid crystal cell is increased, the accumulated charge when a DC voltage is applied to the liquid crystal cell is reduced, and the rubbing resistance of the liquid crystal alignment film is also improved. It can be seen that it improves. Further, from comparison between Examples 3, 5, 7, 14, 16, 18, 20, 22, and 24 and Comparative Example 2, even in the liquid crystal alignment treatment agent containing polyimide, a part or all of the diamine component is represented by the formula. It turns out that the same effect is acquired by setting it as diamine represented by [1]. Further, from the comparison between Example 4 and Example 6 and Example 5 and Example 7, the effect of increasing the liquid crystal pretilt angle is increased by combining the diamine of formula [1] and the diamine of formula [2]. I understand that

With the liquid crystal alignment treatment agent of the present invention, it is possible to obtain an alignment film having a high voltage holding ratio and a small amount of charge accumulated after application of a DC voltage and stopping. Therefore, the liquid crystal display element produced using the liquid crystal aligning agent of the present invention can be a highly reliable liquid crystal display device, and includes a TN liquid crystal display element, an STN liquid crystal display element, a TFT liquid crystal display element, and a VA liquid crystal display. It is suitably used for display elements by various methods such as an element, an IPS liquid crystal display element, and an OCB liquid crystal display element.
The entire contents of the specification, claims, and abstract of Japanese Patent Application No. 2008-158456 filed on June 17, 2008 are incorporated herein as the disclosure of the specification of the present invention. Is.

Claims (11)

The liquid-crystal aligning agent containing at least one of the polyamic acid obtained by making the diamine component and the tetracarboxylic dianhydride component containing the diamine of following formula [1] react, or the polyimide which imidated this polyamic acid.

(In the formula, R represents a saturated hydrocarbon group having 1 to 25 carbon atoms.) The liquid crystal aligning agent according to claim 1, wherein the diamine represented by the formula [1] is 20 to 100 mol% of the total diamine component used for the synthesis of the polyamic acid. The liquid crystal aligning agent of Claim 1 or 2 whose diamine represented by Formula [1] is a diamine which has two amino groups in a meta or para position. The liquid crystal aligning agent of Claim 1 which contains the diamine represented by following formula [2] in the diamine component made to react with a tetracarboxylic dianhydride component.

(In the formula, Ar represents a benzene ring or a naphthalene ring, R ₁ represents an alkylene group having 1 to 5 carbon atoms, and R ₂ represents a hydrogen atom or a methyl group.) The liquid crystal alignment according to any one of claims 1 to 4, wherein the tetracarboxylic dianhydride component is a tetracarboxylic dianhydride component including a tetracarboxylic dianhydride having an alicyclic structure or an aliphatic structure. Processing agent. A liquid crystal alignment film obtained from the liquid crystal aligning agent according to any one of claims 1 to 5. A liquid crystal display device comprising the liquid crystal alignment film according to claim 6. Diamine of the following formula [1-1].

(In the formula, R ₃ is a linear alkyl group having 1 to 5 carbon atoms.) Diamine of the following formula [1-2].

(Wherein R ₄ is a saturated hydrocarbon group having 3 to 8 carbon atoms containing at least one ring structure.) A polyamic acid obtained by reacting the diamine component containing the diamine according to claim 8 or 9 with a tetracarboxylic dianhydride component. A polyimide obtained by imidizing the polyamic acid according to claim 10.