JP5365780B2 - Liquid crystal aligning agent and liquid crystal display element - Google Patents

Abstract

The invention relates to a liquid crystal alignment agent and a liquid crystal display element. The liquid crystal alignment agent provides a liquid crystal alignment film which can form good voltage holding ratio and after image property. The liquid crystal alignment agent comprises at least a polymer selected from groups composed of polyamic acid and imide polymers thereof. The polyamic acid ismade by reacting tetracarboxylicdianhydride and diamine containing compounds expressed by following formula (I) and formula (II) in which n1 is independently integer of 1 to 8.

Description

  The present invention relates to a liquid crystal aligning agent and a liquid crystal display element.

Currently, as a liquid crystal display element, a liquid crystal alignment film made of polyimide or the like is formed on the surface of a substrate on which a transparent conductive film is provided to form a liquid crystal display element substrate, and a pair (two sheets) of the liquid crystal display element are arranged facing each other. A cell having a sandwich structure is formed by filling a layer of nematic liquid crystal having positive dielectric anisotropy in the gap, and the major axis of the liquid crystal molecule is continuously twisted by 90 ° from one substrate to the other substrate. A TN type liquid crystal display element having a so-called TN type (Twisted Nematic) liquid crystal cell is known. Recently, a duty ratio is higher than that of a TN liquid crystal display element, and an STN (Super Twisted Nematic) liquid crystal display element has been developed. This STN type liquid crystal display element uses nematic liquid crystal blended with a chiral agent which is an optically active substance as liquid crystal, and the major axis of the liquid crystal molecule is continuously twisted over 180 ° or more between substrates. The birefringence effect produced by this is utilized. The alignment of liquid crystals in these TN liquid crystal display elements and STN liquid crystal display elements is usually expressed by a liquid crystal alignment film that has been subjected to rubbing treatment.
As another type of liquid crystal display element, a VA (Vertical Alignment) type liquid crystal display element in which liquid crystal molecules having negative dielectric anisotropy are aligned perpendicularly to a substrate is also known. In the VA liquid crystal display element, when a voltage is applied between the substrates and the liquid crystal molecules are inclined in the direction parallel to the substrate, the liquid crystal molecules are inclined from the normal direction of the substrate toward one direction in the substrate surface. It is necessary to. As means for this, for example, an MVA method (Patent Document 1 and Non-Patent Document 1) that controls the alignment direction of liquid crystal by forming protrusions on ITO, and an EVA method that controls the alignment direction by devising the electrode structure ( Non-Patent Document 2), a photo-alignment method (Non-Patent Document 3) that modifies the alignment film by light irradiation and controls the alignment direction has been proposed.

（式（ＩＩＩ）および（ＩＶ）中、ｎ２は、それぞれ、４または６である。）
で表される構造のジアミンから合成されるポリアミック酸またはそのイミド化重合体を含有する液晶配向剤を用いることにより、安定なプレチルト角を与える液晶配向膜が形成されるという。この技術は、液晶配向膜に上記式（ＩＩＩ）または（ＩＶ）で表されるジアミンに由来する液晶類似骨格を導入することによってプレチルト角の安定化を図ったものである。かかる構造を有する重合体を適用することで、垂直配向性の優れた、ＶＡ型液晶表示素子用液晶配向膜（以下、「垂直配向型の液晶配向膜」ともいう。）を形成することができるという。しかし、特許文献２においては、電圧保持率および残像特性は改善されていない。
一方、特許文献３では、テトラカルボン酸二無水物として３，５，６−トリカルボキシ−２−カルボキシメチルノルボルナン−２：３，５：６−二無水物を用いて合成される重合体を含有する液晶配向剤を用いることにより、高温領域での高い電圧保持率を達成すると報告されている。しかし、この技術においても、残像特性を改善するには至っていない。
ここで、液晶表示素子の製造工程に眼を向けると、近年の発展には見るべき進展がある。例えば、一対の基板の間隙内に液晶材料を充填する方法として、従来、間隙を介して一対の基板を対向配置した後、その間隙に液晶を収入する方法が採られてきた。しかし近年、これに代わる新たな方法として、液晶滴下（Ｏｎｅ Ｄｏｒｐ Ｆｉｌｌ＝ＯＤＦ）方式が提案されている（特許文献４）。ＯＤＦ方式は、液晶材料の液滴を基板の液晶配向膜上に滴下し、該液晶滴を対向基板で押し広げつつ、真空中で基板を貼り合わせる方法である。この方法によると、液晶充填工程に要する時間を大幅に短縮できる利点があるが、液晶滴下部分に滴下痕が生じ、これを液晶表示素子としたときに該滴下痕が液晶配向ムラとなって視認されてしまうとの問題が指摘されている。この液晶配向ムラは、液晶配向膜上に液晶材料を滴下したときの衝撃により、液晶配向膜の配向性が局所的に乱れることに起因すると考えられている。この問題を解決するために、液晶配向膜材料からの解決が試みられている（特許文献５）が、未だ不十分であり、特にＯＤＦ方式によりＶＡ型液晶表示素子を製造する場合の上記液晶配向ムラの抑制が求められている。 By the way, it is known that the polyimide obtained by polycondensation of tetracarboxylic dianhydride and diamine is excellent in heat resistance and chemical resistance. Therefore, polyimide is used in various applications, and is widely used as a protective material, an insulating material, etc., particularly in the field of electric and electronic materials. Especially for alignment film applications of liquid crystal display elements, polyimide has been used exclusively from the viewpoint of the durability of the coating film. However, as the performance of liquid crystal display elements and the display density are increased, the surface characteristics of polyimide are particularly emphasized, and superior performance is required compared to conventional polyimide alignment films. It is coming. For example, higher performance is required for liquid crystal alignment regulating power, pretilt angle characteristics, afterimage characteristics, and the like.
The liquid crystal alignment film made of polyimide is usually heated by applying a polyamic acid, which is a polyimide precursor, or a liquid crystal aligning agent, which is an organic solvent solution of a soluble imidized polymer obtained by dehydrating and cyclizing it, onto a substrate. Can be obtained by imidization. According to Patent Document 2, the following formula (III) or (IV)

(In formulas (III) and (IV), n2 is 4 or 6, respectively.)
It is said that a liquid crystal alignment film giving a stable pretilt angle is formed by using a liquid crystal aligning agent containing a polyamic acid synthesized from a diamine having a structure represented by the formula: or an imidized polymer thereof. In this technique, the pretilt angle is stabilized by introducing a liquid crystal-like skeleton derived from the diamine represented by the above formula (III) or (IV) into the liquid crystal alignment film. By applying a polymer having such a structure, a liquid crystal alignment film for a VA liquid crystal display element (hereinafter, also referred to as “vertical alignment liquid crystal alignment film”) having excellent vertical alignment can be formed. That's it. However, in Patent Document 2, the voltage holding ratio and the afterimage characteristics are not improved.
On the other hand, Patent Document 3 contains a polymer synthesized using 3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-dianhydride as tetracarboxylic dianhydride. It is reported that a high voltage holding ratio in a high temperature region is achieved by using a liquid crystal aligning agent. However, this technique has not improved the afterimage characteristics.
Here, when looking at the manufacturing process of the liquid crystal display element, there is a remarkable development in recent years. For example, as a method of filling a liquid crystal material in a gap between a pair of substrates, conventionally, a method has been adopted in which a pair of substrates are arranged to face each other via a gap and then liquid crystal is generated in the gap. However, in recent years, a liquid crystal dropping (One Dorp Fill = ODF) method has been proposed as a new alternative method (Patent Document 4). The ODF method is a method in which droplets of a liquid crystal material are dropped on a liquid crystal alignment film on a substrate, and the substrates are bonded together in a vacuum while the liquid crystal droplets are spread on a counter substrate. According to this method, there is an advantage that the time required for the liquid crystal filling process can be greatly shortened. However, a drop mark is generated in the liquid crystal drop portion, and when this is used as a liquid crystal display element, the drop mark becomes a liquid crystal alignment unevenness. It has been pointed out the problem of being done. This liquid crystal alignment unevenness is considered to be caused by locally disturbing the alignment of the liquid crystal alignment film due to an impact when a liquid crystal material is dropped on the liquid crystal alignment film. In order to solve this problem, attempts have been made to solve the problem using a liquid crystal alignment film material (Patent Document 5). However, the above liquid crystal alignment is particularly insufficient when a VA liquid crystal display element is manufactured by the ODF method. There is a need for suppression of unevenness.

Japanese Patent Laid-Open No. 11-258605 JP 09-278724 A Japanese Patent No. 11-84391 JP-A-6-3635 JP 2007-183564 A JP-A-6-222366 JP-A-6-281937 JP-A-5-107544 JP-A-4-281427

“Liquid Crystal” vol. 3 No. 2 117 (1999) “Liquid Crystal” vol. 3 No. 4 272 (1999) “Jpn J. Appl. Phys.” Vol 36 L428 (1997)

The first object of the present invention is to provide a liquid crystal aligning agent that provides a liquid crystal aligning film excellent in voltage holding ratio and afterimage characteristics. The second object of the present invention is to provide a liquid crystal aligning agent that provides a liquid crystal alignment film that does not cause liquid crystal alignment unevenness due to liquid crystal dropping even when the ODF method is adopted in the liquid crystal filling step. Such a liquid crystal aligning agent of the present invention can be preferably used particularly for forming a liquid crystal alignment film of a vertical alignment type liquid crystal display element.
Still another object of the present invention is to provide a liquid crystal display element excellent in display quality.
Still other objects and advantages of the present invention will become apparent from the following description.

As a result of intensive studies in view of the above circumstances, the present inventors have used a liquid crystal aligning agent containing a specific polymer synthesized using a diamine having a specific structure. The present inventors have found that an excellent liquid crystal alignment film can be formed.
That is, the above objects and advantages of the present invention are as follows.
A liquid crystal aligning agent comprising at least one polymer selected from the group consisting of polyamic acid obtained by reacting tetracarboxylic dianhydride and diamine and an imidized polymer thereof,
The diamine is
Formulas (I) and (II) below

（式（Ｄ−Ｉ）中、Ｘ ^１ は−Ｏ−、−ＣＯＯ−、−ＯＣＯ−、−ＮＨＣＯ−、−ＣＯＮＨ−および−ＣＯ−から選ばれる２価の有機基を示し、Ｒ ^５ はステロイド骨格を有する１価の有機基をし、Ｒ ^６ は炭素数１〜４のアルキル基を示し、ａ１は０〜３の整数を示し、
式（Ｄ−ＩＩ）中、Ｘ ^２ は、それぞれ、−Ｏ−、−ＣＯＯ−、−ＯＣＯ−、−ＮＨＣＯ−、−ＣＯＮＨ−および−ＣＯ−から選ばれる２価の有機基を示し、Ｒ ^７ はステロイド骨格を有する２価の有機基を示し、Ｒ ^８ は、それぞれ、炭素数１〜４のアルキル基を示し、ａ２は、それぞれ、０〜３の整数を示す。）
のそれぞれで表される化合物から選択される少なくとも１種と
を含むものである、前記液晶配向剤によって達成される。
本発明の上記目的および利点は、第二に、
上記液晶配向剤から形成された液晶配向膜を具備する液晶表示素子によって達成される。 (In the above formula, n1 is each independently an integer of 1 to 8.)
At least one member selected from compounds represented by formulas,
The following formulas (D-I) and (D-II)

(In the formula ( DI ), X ¹ represents a divalent organic group selected from —O—, —COO—, —OCO—, —NHCO—, —CONH— and —CO—, and R ⁵ represents a steroid. A monovalent organic group having a skeleton, R ⁶ represents an alkyl group having 1 to 4 carbon atoms, a1 represents an integer of 0 to 3,
In formula (D-II), X ² represents a divalent organic group selected from —O—, —COO—, —OCO—, —NHCO—, —CONH—, and —CO—, respectively, and R ⁷ Represents a divalent organic group having a steroid skeleton, R ⁸ represents an alkyl group having 1 to 4 carbon atoms, and a2 represents an integer of 0 to 3, respectively. )
Monodea containing at least one and <br/> selected from compounds represented by Ru, are achieved by the liquid crystal alignment agent.
The above objects and advantages of the present invention are, secondly,
This is achieved by a liquid crystal display device comprising a liquid crystal alignment film formed from the liquid crystal alignment agent .

The liquid crystal aligning agent of the present invention provides a liquid crystal aligning film excellent in voltage holding ratio and afterimage characteristics. Moreover, the liquid crystal aligning agent of this invention gives the liquid crystal aligning film which does not produce the liquid crystal alignment nonuniformity resulting from a liquid crystal dripping, even when an ODF system is employ | adopted for a liquid crystal filling process. The liquid crystal aligning agent of this invention can be used for TN type | mold and STN type | mold liquid crystal display element etc., and can be used especially suitably especially for VA type | mold liquid crystal display element.
The liquid crystal display element of the present invention can be effectively used in various devices, and is suitably used for display devices such as a desk calculator, wristwatch, table clock, counting display board, word processor, personal computer, and liquid crystal television.

Schematic explanatory drawing which shows the structure of the transparent electrode for afterimage characteristic evaluation.

Hereinafter, the present invention will be described in detail.
The liquid crystal aligning agent of the present invention contains at least one polymer selected from the group consisting of a polyamic acid obtained by reacting tetracarboxylic dianhydride and a diamine and an imidized polymer thereof , provided that the diamine But,
At least one selected from the compounds represented by each of the above formulas (I) and (II) ;
It, characterized in that comprises at least one and <br/> selected from the formula (D-I) and (D-II) of the compound represented by each.
<Tetracarboxylic dianhydride>
Examples of the tetracarboxylic dianhydride that can be used for synthesizing the polyamic acid used in the present invention include, for example, butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1, 2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dichloro-1, 2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclo Pentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3 ′, 4,4′-dicyclohexyltetracarboxylic dianhydride, 2,3,5 Tricarboxycyclopentylacetic acid dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3 -Furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5-methyl-5 (tetrahydro-2,5-dioxo-3 -Furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5-ethyl-5- (tetrahydro-2,5-dioxo- 3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-7-methyl-5- (tetrahydro-2,5-dioxo -3-furanyl) -naphtho [ 1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-7-ethyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl)- Naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8-ethyl-5- (tetrahydro-2,5-dioxo-3-furanyl) Naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5,8-dimethyl-5- (tetrahydro-2,5-dioxo-3 -Furanyl) -naphtho [1,2-c] -furan-1,3-dione, 5- ( , 5-dioxotetrahydrofuranyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, bicyclo [2.2.2] -oct-7-ene-2,3,5,6-tetra Carboxylic dianhydride, 3-oxabicyclo [3.2.1] octane-2,4-dione-6-spiro-3 '-(tetrahydrofuran-2', 5'-dione), 5- (2,5 -Dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6- Dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^2,6 ] undecane-3,5,8,10-tetraone, the following formulas (TI) and (T-II)

（式中、Ｒ^１およびＲ^３は、それぞれ、芳香環を有する２価の有機基を示し、Ｒ^２およびＲ^４は、それぞれ、水素原子またはアルキル基を示し、複数存在するＲ^２およびＲ^４はそれぞれ同一でも異なっていてもよい。）
のそれぞれで表される化合物などの脂肪族テトラカルボン酸二無水物および脂環式テトラカルボン酸二無水物；
ピロメリット酸二無水物、３，３’，４，４’−ベンゾフェノンテトラカルボン酸二無水物、３，３’，４，４’−ビフェニルスルホンテトラカルボン酸二無水物、１，４，５，８−ナフタレンテトラカルボン酸二無水物、２，３，６，７−ナフタレンテトラカルボン酸二無水物、３，３’，４，４’−ビフェニルエーテルテトラカルボン酸二無水物、３，３’，４，４’−ジメチルジフェニルシランテトラカルボン酸二無水物、３，３’，４，４’−テトラフェニルシランテトラカルボン酸二無水物、１，２，３，４−フランテトラカルボン酸二無水物、４，４’−ビス（３，４−ジカルボキシフェノキシ）ジフェニルスルフィド二無水物、４，４’−ビス（３，４−ジカルボキシフェノキシ）ジフェニルスルホン二無水物、４，４’−ビス（３，４−ジカルボキシフェノキシ）ジフェニルプロパン二無水物、３，３’，４，４’−パーフルオロイソプロピリデンジフタル酸二無水物、３，３’，４，４’−ビフェニルテトラカルボン酸二無水物、２，２’，３，３’−ビフェニルテトラカルボン酸二無水物、ビス（フタル酸）フェニルホスフィンオキサイド二無水物、ｐ−フェニレン−ビス（トリフェニルフタル酸）二無水物、ｍ−フェニレン−ビス（トリフェニルフタル酸）二無水物、ビス（トリフェニルフタル酸）−４，４’−ジフェニルエーテル二無水物、ビス（トリフェニルフタル酸）−４，４’−ジフェニルメタン二無水物、エチレングリコール−ビス（アンヒドロトリメリテート）、プロピレングリコール−ビス（アンヒドロトリメリテート）、１，４−ブタンジオール−ビス（アンヒドロトリメリテート）、１，６−ヘキサンジオール−ビス（アンヒドロトリメリテート）、１，８−オクタンジオール−ビス（アンヒドロトリメリテート）、２，２−ビス（４−ヒドロキシフェニル）プロパン−ビス（アンヒドロトリメリテート）、下記式（Ｔ−１）〜（Ｔ−４）

(Wherein R ¹ and R ³ each represents a divalent organic group having an aromatic ring, R ² and R ⁴ each represent a hydrogen atom or an alkyl group, and a plurality of R ² and R ^{4 are present.} May be the same or different.)
An aliphatic tetracarboxylic dianhydride and an alicyclic tetracarboxylic dianhydride such as a compound represented by each of the following:
Pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenylsulfone tetracarboxylic dianhydride, 1,4,5, 8-naphthalene tetracarboxylic dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyl ether tetracarboxylic dianhydride, 3,3 ′, 4,4′-dimethyldiphenylsilanetetracarboxylic dianhydride, 3,3 ′, 4,4′-tetraphenylsilanetetracarboxylic dianhydride, 1,2,3,4-furantetracarboxylic dianhydride 4,4′-bis (3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenylsulfone dianhydride, 4,4′-bis ( 3,4-dicar Boxyphenoxy) diphenylpropane dianhydride, 3,3 ′, 4,4′-perfluoroisopropylidene diphthalic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2 , 2 ′, 3,3′-biphenyltetracarboxylic dianhydride, bis (phthalic acid) phenylphosphine oxide dianhydride, p-phenylene-bis (triphenylphthalic acid) dianhydride, m-phenylene-bis ( Triphenylphthalic acid) dianhydride, bis (triphenylphthalic acid) -4,4′-diphenyl ether dianhydride, bis (triphenylphthalic acid) -4,4′-diphenylmethane dianhydride, ethylene glycol-bis ( Anhydrotrimellitate), propylene glycol-bis (anhydrotrimellitate), 1,4-butanediol-bis (anhydrotrimellitate) Retate), 1,6-hexanediol-bis (anhydrotrimellitate), 1,8-octanediol-bis (anhydrotrimellitate), 2,2-bis (4-hydroxyphenyl) propane-bis ( Anhydrotrimellitate), the following formulas (T-1) to (T-4)

An aromatic tetracarboxylic dianhydride such as a compound represented by each of the above can be exemplified. These may be used alone or in combination of two or more.
The tetracarboxylic dianhydride used for synthesizing the polyamic acid used in the present invention includes butanetetracarboxylic dianhydride and 1,2,3,4-cyclobutanetetracarboxylic dianhydride. 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid Dianhydride, 3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-dianhydride, 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro- 2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro 2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5,8-dimethyl-5- ( Tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, bicyclo [2.2.2] -oct-7-ene-2,3,5 6-tetracarboxylic dianhydride, 3-oxabicyclo [3.2.1] octane-2,4-dione-6-spiro-3 ′-(tetrahydrofuran-2 ′, 5′-dione), 5- ( 2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5 : 6-dianhydride, 4,9-dioxatricyclo [ .3.1.0 ^2,6] undecane -3,5,8,10- tetraone, pyromellitic dianhydride, 3,3 ', 4,4'-benzophenone tetracarboxylic dianhydride, 3,3 ', 4,4'-biphenylsulfonetetracarboxylic dianhydride, 2,2', 3,3'-biphenyltetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, Of the compounds represented by the above formula (TI), the following formulas (T-5) to (T-7)

And the following formula (T-8) among the compounds represented by formula (T-II):

It is preferable from the viewpoint that it can exhibit good liquid crystal alignment properties including at least one selected from the group consisting of the compounds represented by (hereinafter referred to as “specific tetracarboxylic dianhydride”). .
Specific tetracarboxylic dianhydrides include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 1,3,3a, 4,5, 9b-Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro- 8-Methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 3-oxabicyclo [3.2.1] octane-2 , 4-dione-6-spiro-3 ′-(tetrahydrofuran-2 ′, 5′-dione), 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1, 2-dicarboxylic anhydride, 5,6 tricarboxy-2-carboxymethyl norbornane -2: 3,5: 6-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^{2, 6]} undecane -3, At least one selected from the group consisting of 5,8,10-tetraone, pyromellitic dianhydride and the compound represented by the above formula (T-1) is preferable, and in particular, 3,5,6-tricarboxy- 2-Carboxymethylnorbornane-2: 3,5: 6-dianhydride is preferred.
The tetracarboxylic dianhydride used for synthesizing the polyamic acid used in the present invention is a specific tetracarboxylic dianhydride as described above of 80 mol% or more based on the total tetracarboxylic dianhydride. It is preferable that it is contained, more preferably 90 mol% or more, and particularly preferably 95 mol% or more.

<Diamine>
The diamine used for synthesizing the polyamic acid used in the present invention includes at least one selected from the compounds represented by the formulas (I) and (II).
In the above formulas (I) and (II), n1 is preferably an integer of 3 to 6, respectively. The two amino groups bonded to the benzene ring are preferably located at the 2, 4 position or the 3, 5 position with respect to other substituents.
The compound represented by the above formula (I) is, for example, a dinitro compound obtained after dehydrohalogenation condensation of the corresponding 4- (4- (4-n-alkylcyclohexyl) cyclohexyl) phenol and halogenated dinitrobenzene. Can be synthesized by reducing. The compound represented by the above formula (II) is, for example, a dinitro compound obtained after an esterification reaction between corresponding 4- (4- (4-n-alkylcyclohexyl) cyclohexyl) phenol and dinitrobenzoic acid chloride. Can be synthesized by reducing.
The compound represented by each of the above formulas (I) and (II) may have a benzene ring substituted with one or two or more alkyl groups having 1 to 4 carbon atoms (preferably a methyl group). Good.

As the diamine used for synthesizing the polyamic acid used in the present invention, at least one selected from the compounds represented by the above formulas (I) and (II) and another diamine are used in combination. The
Examples of the other diamine that will be used together, for example, the following formula (D-I)

(In the formula (DI), X ¹ represents a divalent organic group selected from —O—, —COO—, —OCO—, —NHCO—, —CONH— and —CO—, and R ⁵ represents a steroid. A monovalent organic group having a skeleton, R ⁶ represents an alkyl group having 1 to 4 carbon atoms, and a1 represents an integer of 0 to 3).
A compound represented by formula (D-II):

(In Formula (D-II), X ² represents a divalent organic group selected from —O—, —COO—, —OCO—, —NHCO—, —CONH—, and —CO—, respectively; ⁷ represents a divalent organic group having a steroid skeleton, R ⁸ represents an alkyl group having 1 to 4 carbon atoms, and a2 represents an integer of 0 to 3, respectively.
A diamine having a steroid skeleton such as a compound represented by:
p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylethane, 4,4′-diaminodiphenylsulfide, 4,4′-diaminodiphenylsulfone, 4,4′- Diaminobenzanilide, 4,4′-diaminodiphenyl ether, 1,5-diaminonaphthalene, 2,2′-dimethyl-4,4′-diaminobiphenyl, 3,3′-dimethyl-4,4′-diaminobiphenyl, 2, , 2′-ditrifluoromethyl-4,4′-diaminobiphenyl, 3,3′-ditrifluoromethyl-4,4′-diaminobiphenyl, 5-amino-1- (4′-aminophenyl) -1,3 , 3-trimethylindane, 6-amino-1- (4′-aminophenyl) -1,3,3-trimethylindane, 3,4′-diamino Phenyl ether, 3,3′-diaminobenzophenone, 3,4′-diaminobenzophenone, 4,4′-diaminobenzophenone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, bis [4- (4-aminophenoxy) phenyl] sulfone, 1,4-bis ( 4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 9,9-bis (4-aminophenyl) -10-hydroanthracene, 2,7-diaminofluorene, 9,9-dimethyl-2,7-diaminofluorene, 9,9-bis (4-aminophenyl) Nyl) fluorene, 4,4′-methylene-bis (2-chloroaniline), 2,2 ′, 5,5′-tetrachloro-4,4′-diaminobiphenyl, 2,2′-dichloro-4,4 '-Diamino-5,5'-dimethoxybiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 4,4'-(p-phenylenediisopropylidene) bisaniline, 4,4 '-(m- Phenylenediisopropylidene) bisaniline, 2,2′-bis [4- (4-amino-2-trifluoromethylphenoxy) phenyl] hexafluoropropane, 4,4′-diamino-2,2′-bis (trifluoro) Methyl) biphenyl, 4,4′-bis [(4-amino-2-trifluoromethyl) phenoxy] -octafluorobiphenyl, 4,4′-bis (4-aminophenoxy) biphenyl Which aromatic diamine;

1,1-metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, 1,4-diaminocyclohexane, isophoronediamine, Tetrahydrodicyclopentadienylenediamine, hexahydro-4,7-methanoindanylene methylene diamine, tricyclo [6.2.1.0 ^2,7 ] -undecylene dimethyl methylene diamine, 4,4'-methylene bis (cyclohexyl amine) ), 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane and other aliphatic and alicyclic diamines;
2,3-diaminopyridine, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 5,6-diamino-2,3-dicyanopyrazine, 5,6-diamino-2,4 -Dihydroxypyrimidine, 2,4-diamino-6-dimethylamino-1,3,5-triazine, 1,4-bis (3-aminopropyl) piperazine, 2,4-diamino-6-isopropoxy-1,3 , 5-triazine, 2,4-diamino-6-methoxy-1,3,5-triazine, 2,4-diamino-6-phenyl-1,3,5-triazine, 2,4-diamino-6-methyl -S-triazine, 2,4-diamino-1,3,5-triazine, 4,6-diamino-2-vinyl-s-triazine, 2,4-diamino-5-phenylthiazole, 2,6- Aminopurine, 5,6-diamino-1,3-dimethyluracil, 3,5-diamino-1,2,4-triazole, 6,9-diamino-2-ethoxyacridine lactate, 3,8-diamino-6 Phenylphenanthridine, 1,4-diaminopiperazine, 3,6-diaminoacridine, bis (4-aminophenyl) phenylamine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, N-ethyl -3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N, N'-bis (4-aminophenyl) -benzidine, N, N'-bis (4-aminophenyl) -N, N '-Dimethylbenzidine, the following formula (D-III)

(In formula (D-III), R ⁹ represents a monovalent organic group having a ring structure containing a nitrogen atom selected from pyridine, pyrimidine, triazine, piperidine and piperazine, and X ³ represents a divalent organic group. R ¹⁰ represents an alkyl group having 1 to 4 carbon atoms, and a3 represents an integer of 0 to 3.)
A compound represented by formula (D-IV):

(In Formula (D-IV), R ¹¹ represents a divalent organic group having a ring structure containing a nitrogen atom selected from pyridine, pyrimidine, triazine, piperidine and piperazine, and X ⁴ represents a divalent organic group, respectively. A plurality of X ⁴ may be the same or different, R ¹² represents an alkyl group having 1 to 4 carbon atoms, and a4 represents an integer of 0 to 3, respectively.
A diamine having two primary amino groups and a nitrogen atom other than the primary amino group in the molecule, such as a compound represented by:
Following formula (D-V)

(In the formula (D-V), X ⁵ represents a divalent organic group selected from —O—, —COO—, —OCO—, —NHCO—, —CONH— and —CO—, and R ¹³ represents tri A monovalent organic group having a group selected from a fluoromethylphenyl group, a trifluoromethoxyphenyl group and a fluorophenyl group or an alkyl group having 6 to 30 carbon atoms, and R ¹⁴ represents an alkyl group having 1 to 4 carbon atoms. A5 represents an integer of 0 to 3.)
Monosubstituted phenylenediamines such as compounds represented by:
The following formula (D-VI)

(In the formula (D-VI), each R ¹⁵ represents a hydrocarbon group having 1 to 12 carbon atoms, and a plurality of R ¹⁵ may be the same or different, and p is each 1 is an integer of 1 to 3, and q is an integer of 1 to 20.)
Diaminoorganosiloxanes such as compounds represented by:
The following formulas (D-1) to (D-2)

(Y in formula (D-1) is an integer of 2 to 12, and z in formula (D-2) is an integer of 1 to 5.)
And the like, and the like. The aromatic diamine and the benzene ring of the compound represented by each of the formulas (D-1) and (D-2) are one or two or more alkyl groups having 1 to 4 carbon atoms (preferably a methyl group). ) May be substituted.
These diamines can be used alone or in combination of two or more.
R ⁶ , R ⁸ , R ¹⁰ , R ¹² and R ¹⁴ in the above formulas (D-I), (D-II), (D-III), (D-IV) and (D-V) are respectively It is preferably a methyl group, and a1, a2, a3, a4 and a5 are each preferably 0 or 1, and more preferably 0.
The steroid skeleton in R ⁵ and R ⁶ of the above formulas (D-I) and (D-II) is a skeleton composed of a cyclopentano-perhydrophenanthrene nucleus or one or two or more of its carbon-carbon bonds are doubled. A skeleton that is connected. The monovalent organic group of R ^{5 and} the divalent organic group of R ⁶ each having such a steroid skeleton are preferably those having 17 to 40 carbon atoms, and more preferably those having 17 to 30 carbon atoms.
Specific examples of R ⁵ include, for example, a cholestane-3-yl group, a cholesta-5-en-3-yl group, a cholesta-24-en-3-yl group, and a cholesta-5,24-dien-3-yl group. Lanostane-3-yl group, lanosta-5-en-3-yl group, lanosta-24-en-3-yl group, lanosta-5,24-dien-3-yl group, etc .; specific examples of R ⁶ For example, cholestane-3,6-diyl group, cholesta-5-ene-3,6-diyl group, cholesta-24-ene-3,6-diyl group, cholestane-3,3-diyl group, lanostane- A 3,6-diyl group, a lanostane-3,3-diyl group, etc. can be mentioned, respectively.
Specific examples of the compound represented by the above formula (DI) include, for example, the following formulas (D-3) to (D-7):

Specific examples of the compound represented by each of the above formulas (D-II) include, for example, the following formulas (D-8) to (D-10):

The compounds represented by each of the above can be mentioned respectively.
Among the other diamines, the above Symbol formula (D-I) represented by compounds and the formula in (D-II) at least one member selected from the group consisting of compounds represented by formula (hereinafter, "other specific Diamine (1) ") is essential, and preferred are p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfide, 1,5-diaminonaphthalene, 2,2 '-Dimethyl-4,4'-diaminobiphenyl,2,2'-ditrifluoromethyl-4,4'-diaminobiphenyl, 2,7-diaminofluorene, 4,4'-diaminodiphenyl ether, 2,2-bis [4 -(4-aminophenoxy) phenyl] propane, 9,9-bis (4-aminophenyl) fluorene, 2,2-bis [4- (4-aminophenoxy) pheny ] Hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4 '-(p-phenylenediisopropylidene) bisaniline, 4,4'-(m-phenylenediisopropylidene) bisaniline, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, 1,4-diaminocyclohexane, 4,4′-methylenebis (cyclohexylamine), 1,3-bis (Aminomethyl) cyclohexane, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminoacridine, 3,6-diaminocarbazole, N-methyl-3,6-diamino Carbazole, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-di Mino carbazole, N, N'-bis (4-aminophenyl) - benzidine, formula of the compound represented by the above formula (D-III) (D-11)

Of the compounds represented by formula (D-IV), the following formula (D-12)

Of the compounds represented by the formula (D-V), dodecanoxy-2,4-diaminobenzene, pentadecanoxy-2,4-diaminobenzene, hexadecanoxy-2,4-diaminobenzene, octadecanoxy- 2,4-diaminobenzene, dodecanoxy-2,5-diaminobenzene, pentadecanoxy-2,5-diaminobenzene, hexadecanoxy-2,5-diaminobenzene, octadecanoxy-2,5-diaminobenzene, the following formula (D-13) ~ (D-15)

And at least one selected from the group consisting of 1,3-bis (3-aminopropyl) -tetramethyldisiloxane among the compounds represented by formula (D-VI) Hereinafter, it is referred to as “other specific diamine (2)”.
As for the diamine used for synthesizing the polyamic acid used in the present invention, at least one selected from the compounds represented by each of the above formulas (I) and (II) is 5 It is preferable to contain more than mol%, more preferably 10 to 90 mol%, more preferably 20 to 80 mol%, particularly preferably 30 to 50 mol%.
The diamine used for synthesizing the polyamic acid used in the present invention is at least one selected from the compounds represented by each of the above formulas (I) and (II), as well as the other diamines described above. all SANYO comprising at least one member selected from the group consisting of specific diamine (1) and a specific diamine (2), but other specific diamine (1) is required and other specific diamine (1) and the specific The content of at least one selected from the group consisting of diamine (2) is preferably 10 to 90 mol%, more preferably 20 to 80 mol%, and more preferably 50 to 70 mol% based on the total diamine. % Is preferable.
Diamine used to synthesize the polyamic acid used in the present invention, particularly preferably less (1) or (2) of the (2).
(1) It contains at least one selected from the compounds represented by each of the above formulas (I) and (II) in the above ratio, and further contains another specific diamine (2) with respect to the total diamine. Is a diamine containing 10 to 90 mol%, more preferably 20 to 80 mol%, still more preferably 50 to 70 mol%.
(2) It contains at least one selected from the compounds represented by each of the above formulas (I) and (II) in the above ratio, and further contains another specific diamine (1) with respect to all diamines. Is a diamine containing 1 to 20 mol%, more preferably 5 to 10 mol%.
In the case of the above (2), it is particularly preferable that at least one selected from the compounds represented by the above formulas (I) and (II), the other specific diamine (1) and the other specific diamine (2 ). These content ratios are the above ratios for at least one selected from the compounds represented by the formulas (I) and (II) and the specific diamine (1), respectively, and the specific diamine (2) Is preferably from 10 to 80 mol%, more preferably from 20 to 70 mol%, based on the total diamine.

<Synthesis of polyamic acid>
The polyamic acid used in the present invention can be synthesized by reacting the tetracarboxylic dianhydride as described above with a diamine.
The ratio of the tetracarboxylic dianhydride and the diamine used for the polyamic acid synthesis reaction is such that the acid anhydride group of the tetracarboxylic dianhydride is 0.5 equivalent to 1 equivalent of the amino group contained in the diamine. The ratio which becomes -2 equivalent is preferable, More preferably, it is the ratio which becomes 0.7-1.2 equivalent.
The polyamic acid synthesis reaction is preferably carried out in an organic solvent, preferably at a temperature of -20 to 150 ° C, more preferably at a temperature of 0 to 100 ° C, preferably 0.5 to 120 hours, more preferably 2 to 10 hours. The reaction time is as follows.
Here, the organic solvent is not particularly limited as long as it can dissolve the synthesized polyamic acid. For example, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide And aprotic polar solvents such as γ-butyrolactone, tetramethylurea and hexamethylphosphortriamide; and phenolic solvents such as m-cresol, xylenol, phenol and halogenated phenol. The amount (a) of the organic solvent used is such that the total amount (b) of the tetracarboxylic dianhydride and the diamine compound is 0.1 to 30% by weight with respect to the total amount (a + b) of the reaction solution. It is preferable. In addition, when using together an organic solvent and the poor solvent mentioned later, the usage-amount of this organic solvent should be understood as meaning the total usage-amount of an organic solvent and a poor solvent.

For the organic solvent, alcohol, ketone, ester, ether, halogenated hydrocarbon, hydrocarbon and the like, which are poor solvents for polyamic acid, can be used in combination as long as the polyamic acid to be produced does not precipitate. Specific examples of the poor solvent include, for example, methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, ethylene glycol monomethyl ether, ethyl lactate, butyl lactate, Acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, diethyl oxalate, diethyl malonate, diethyl ether, ethylene glycol methyl ether, ethylene Glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol-n- Chill ether, ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, tetrahydrofuran, dichloromethane, 1,2-dichloroethane, 1 , 4-dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene, hexane, heptane, octane, benzene, toluene, xylene, isoamylpropionate, isoamylisobutyrate, diisopentyl ether and the like.
When the organic solvent and the poor solvent are used in combination in the synthesis of the polyamic acid, the use ratio of the poor solvent is preferably 20% by weight or less, more preferably 10% by weight with respect to the total of the organic solvent and the poor solvent. It is as follows.

  As described above, a reaction solution obtained by dissolving polyamic acid is obtained. This reaction solution may be used as it is for the preparation of the liquid crystal aligning agent, may be used for the preparation of the liquid crystal aligning agent after isolating the polyamic acid contained in the reaction solution, or the isolated polyamic acid was purified. You may use for preparation of a liquid crystal aligning agent. Polyamic acid can be isolated by pouring the reaction solution into a large amount of poor solvent to obtain a precipitate, and drying the precipitate under reduced pressure, or by distilling the reaction solution under reduced pressure using an evaporator. it can. Further, the polyamic acid can be purified by a method of dissolving the polyamic acid again in an organic solvent and then precipitating with a poor solvent, or a method of performing the step of distilling under reduced pressure with an evaporator once or several times.

<Imidized polymer>
The imidized polymer used in the present invention can be obtained by dehydrating and ring-closing the amic acid structure of the polyamic acid as described above to imidize. Here, a complete imidized product in which all of the amic acid structure of the polyamic acid is dehydrated and closed may be used, or an imidized polymer in which the amic acid structure and the imide ring coexist. The imidization rate of the imidized polymer used in the present invention is preferably 50% or more, more preferably 55 to 95%, and particularly preferably 60 to 90%. Here, the “imidation rate” is a percentage of the number of imide rings to the total of the number of amic acid structures and the number of imide rings in the imidized polymer. At this time, a part of the imide ring may be an isoimide ring.
The polyamic acid is dehydrated and closed by (i) a method of heating the polyamic acid, or (ii) dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydrating ring-closing catalyst to this solution, and heating as necessary. It can be done by a method.
The reaction temperature in the method of heating the polyamic acid (i) is preferably 50 to 200 ° C, more preferably 60 to 170 ° C. When the reaction temperature is less than 50 ° C., the dehydration ring-closing reaction does not proceed sufficiently, and when the reaction temperature exceeds 200 ° C., the molecular weight of the imidized polymer obtained may decrease. The reaction time is preferably 1 to 120 hours, more preferably 2 to 30 hours.
In the method (ii) of adding a dehydrating agent and a dehydrating ring-closing catalyst to the polyamic acid solution, for example, an acid anhydride such as acetic anhydride, propionic anhydride, or trifluoroacetic anhydride can be used. . The amount of the dehydrating agent used is preferably 0.01 to 20 mol with respect to 1 mol of the polyamic acid repeating unit. Moreover, as a dehydration ring closure catalyst, tertiary amines, such as a pyridine, a collidine, a lutidine, a triethylamine, can be used, for example. However, it is not limited to these. The amount of the dehydration ring closure catalyst used is preferably 0.01 to 10 moles per mole of the dehydrating agent used. In addition, as an organic solvent used for dehydration ring closure reaction, the organic solvent illustrated as what is used for the synthesis | combination of a polyamic acid can be mentioned. The reaction temperature of the dehydration ring closure reaction is preferably 0 to 180 ° C, more preferably 10 to 150 ° C. The reaction time is preferably 0.5 to 30 hours, more preferably 2 to 10 hours.

  The imidized polymer obtained in the above method (i) may be used for the preparation of a liquid crystal aligning agent as it is, or may be used for the preparation of a liquid crystal aligning agent after purifying the obtained imidized polymer. . On the other hand, in the method (ii), a reaction solution containing an imidized polymer is obtained. This reaction solution may be directly used for the preparation of the liquid crystal aligning agent, or may be used for the preparation of the liquid crystal aligning agent after removing the dehydrating agent and the dehydrating ring-closing catalyst from the reaction solution. After separating, it may be used for preparing a liquid crystal aligning agent, or the isolated imidized polymer may be purified and then used for preparing a liquid crystal aligning agent. In order to remove the dehydrating agent and the dehydrating ring-closing catalyst from the reaction solution, for example, a method such as solvent replacement can be applied. Isolation and purification of the imidized polymer can be performed by performing the same operations as described above as the method for isolating and purifying the polyamic acid.

<End-modified polymer>
The polyamic acid and the imidized polymer may each be a terminal-modified type having a controlled molecular weight. Such a terminal-modified polymer can be synthesized by adding an appropriate molecular weight regulator such as acid monoanhydride, monoamine compound, monoisocyanate compound to the reaction system when synthesizing the polyamic acid. . Here, as the acid monoanhydride, for example, maleic anhydride, phthalic anhydride, itaconic anhydride, n-decyl succinic anhydride, n-dodecyl succinic anhydride, n-tetradecyl succinic anhydride , N-hexadecyl succinic anhydride and the like. Examples of the monoamine compound include aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, n-undecylamine, Examples include n-dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecylamine, n-octadecylamine, and n-eicosylamine. it can. Examples of the monoisocyanate compound include phenyl isocyanate and naphthyl isocyanate.
The use ratio of the molecular weight regulator is preferably 20 parts by weight or less, more preferably 10 parts by weight, based on 100 parts by weight of the total of tetracarboxylic dianhydride and diamine used when synthesizing the polyamic acid. It is as follows.

<Solution viscosity of polymer>
The polyamic acid and the imidized polymer obtained as described above preferably have a solution viscosity of 20 to 800 mPa · s, respectively, when the solution has a concentration of 10% by weight, and preferably 30 to 500 mPa · s. More preferably, it has a solution viscosity of s.
The solution viscosity (mPa · s) of the above polymer is E for a polymer solution having a concentration of 10% by weight prepared using a good solvent for the polymer (for example, N-methyl-2-pyrrolidone, γ-butyrolactone, etc.). It is a value measured at 25 ° C. using a mold rotational viscometer.

<Other ingredients>
The liquid crystal aligning agent of the present invention contains at least one polymer selected from the group consisting of the above polyamic acid and its imidized polymer as an essential component, but the effects and advantages of the present invention are other than that. Other components may be contained as long as they are not impaired. Examples of such other components include other polymers, compounds having at least one epoxy group in the molecule (hereinafter referred to as “epoxy compound”), and functional silane compounds.
Examples of the other polymer are obtained by reacting, for example, polyorganosiloxane, tetracarboxylic dianhydride and a diamine not containing any of the compounds represented by the above formulas (I) and (II). Polyamic acid (hereinafter referred to as “other polyamic acid”) and imidized polymer thereof (hereinafter referred to as “other imidized polymer”), polyamic acid ester, polyester, polyamide, cellulose derivative, polyacetal, polystyrene derivative , Poly (styrene-phenylmaleimide) derivatives, poly (meth) acrylates, and the like. Of these, other polyamic acids or other imidized polymers are preferred from the viewpoint of excellent varnish properties and electrical characteristics.
The tetracarboxylic dianhydrides used to synthesize other polyamic acids and other imidized polymers are the same as those exemplified as the tetracarboxylic dianhydrides used to synthesize the polyamic acids. . The diamine used for synthesizing other polyamic acid and other imidized polymer is the same as that exemplified as the other diamine that can be used for synthesizing the polyamic acid. In this case, a diamine containing 70 mol% or more, and more preferably 90 mol% or more, of at least one selected from the other specific diamines (1) and (2) with respect to the total diamine is more preferable. Other polyamic acids and other imidized polymers are polyamic acids and imidized, except that diamines that do not contain any of the compounds represented by the above formulas (I) and (II) are used as diamines. The polymer can be synthesized in the same manner as described above. Of the other polyamic acids and other imidized polymers, other polyamic acids are preferred.
The proportion of the other polymer used in the liquid crystal aligning agent of the present invention is the sum of the polymers (tetracarboxylic dianhydride and diamine containing a compound represented by the above formula (I) or (II) are reacted. The total of the resulting polyamic acid and its imidized polymer and other polymers optionally used, the same shall apply hereinafter)), preferably 80% by weight or less, more preferably 60% by weight or less. Furthermore, it is preferable that it is 40 weight% or less.

The epoxy compound can be used from the viewpoint of further improving the adhesion of the liquid crystal aligning agent formed from the liquid crystal aligning agent of the present invention to the substrate surface. For example, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene Glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, glycerin diglycidyl ether, 2,2 -Dibromoneopentyl glycol diglycidyl ether, N, N, N ', N'-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-dig Preferable examples are (cidylaminomethyl) cyclohexane, N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane, N, N-diglycidyl-benzylamine, N, N-diglycidyl-aminomethylcyclohexane and the like. Can be mentioned. The compounding ratio of these epoxy compounds is preferably 40 parts by weight or less, more preferably 0.1 to 30 parts by weight with respect to 100 parts by weight of the total amount of the polymer.
Examples of the functional silane compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl)- 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyl Trimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4 7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, 9- Methyl trimethoxysilyl-3,6-diazananoate, methyl 9-triethoxysilyl-3,6-diazananoate, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, glycidoxymethyltrimethoxysilane, glycidoxymethyltriethoxysilane, 2-glycidoxyethyltrimethoxysilane, 2-glycidoxyethyltriethoxysilane, 3 Glycidoxypropyltrimethoxysilane, and 3-glycidoxypropyl triethoxy silane and the like.
The blending ratio of these functional silane compounds is preferably 2 parts by weight or less, more preferably 0.2 parts by weight or less, with respect to 100 parts by weight of the total polymer.

<Liquid crystal aligning agent>
In the liquid crystal aligning agent of the present invention, at least one polymer selected from the group consisting of the polyamic acid and its imidized polymer as described above and other components optionally added are preferably dissolved in an organic solvent. Contained and configured.
As the polymer, only polyamic acid may be used, only imidized polymer may be used, or both polyamic acid and imidized polymer may be used. The polymer contained in the liquid crystal aligning agent of the present invention is preferably an imidized polymer or a combination of a polyamic acid and an imidized polymer. Here, the number of amic acid structures possessed by the polyamic acid contained in the liquid crystal aligning agent, the number of amic acid structures possessed by the imidized polymer, and the number of imide rings possessed by the imidized polymer relative to the total number of imide rings Ratio (hereinafter referred to as “average imidation ratio”. When the liquid crystal aligning agent of the present invention contains other polyamic acid and other imidized polymer, the average imidization ratio is calculated including these. It should be understood as a numerical value.) Is preferably 40% or more, more preferably 45 to 90%, and particularly preferably 50 to 80%.
As an organic solvent which can be used for the liquid crystal aligning agent of this invention, the solvent illustrated above can be mentioned as what is used for the synthesis reaction of a polyamic acid. Moreover, the poor solvent illustrated as what can be used together in the case of the synthesis reaction of a polyamic acid can also be selected suitably, and can be used together.

  Particularly preferable organic solvents that can be used in the liquid crystal aligning agent of the present invention include, for example, N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N, N-dimethylformamide, N, N-dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol n-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethyl Lenglycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, isoamyl propionate, isoamyl isobutyrate, diisobutyl ketone, diisopentyl ether, ethylene carbonate, propylene A carbonate etc. can be mentioned. These can be used alone or in admixture of two or more. A particularly preferable solvent composition is a composition obtained by combining the above-mentioned solvents, wherein no polymer is precipitated in the aligning agent, and the surface tension of the aligning agent is in the range of 25 to 40 mN / m. It is.

The solid concentration in the liquid crystal aligning agent of the present invention (the ratio of the total weight of components other than the solvent contained in the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) is selected in consideration of viscosity, volatility, and the like. However, it is preferably in the range of 1 to 10% by weight. That is, the liquid crystal aligning agent of the present invention is applied to the substrate surface, and a coating film to be a liquid crystal aligning film is formed by removing the solvent. When the solid content concentration is less than 1% by weight, If the coating film thickness is too small to obtain a good liquid crystal alignment film, and if the solid content concentration exceeds 10% by weight, the coating film thickness will be too large to produce a good liquid crystal alignment film. It is difficult to obtain, and the viscosity of the liquid crystal aligning agent increases, resulting in poor coating properties.
The particularly preferable solid content concentration range varies depending on the method used when applying the liquid crystal aligning agent to the substrate. For example, when the spinner method is used, the range of 1.5 to 4.5% by weight is particularly preferable. In the case of the printing method, it is particularly preferable that the solid content concentration is in the range of 3 to 9% by weight, and thereby the solution viscosity is in the range of 12 to 50 mPa · s. In the case of the ink jet method, it is particularly preferable that the solid content concentration is in the range of 1 to 5% by weight, and thereby the solution viscosity is in the range of 3 to 15 mPa · s.
The temperature at which the liquid crystal aligning agent of the present invention is prepared is preferably 0 ° C to 200 ° C, more preferably 20 ° C to 60 ° C.

<Liquid crystal display element>
The liquid crystal display element of the present invention comprises a liquid crystal alignment film formed from the liquid crystal aligning agent of the present invention as described above. The liquid crystal alignment film formed from the liquid crystal alignment agent of the present invention exhibits a high voltage holding ratio and good afterimage characteristics to the maximum when used as a vertical alignment type liquid crystal alignment film.
The liquid crystal display element of the present invention can be produced, for example, by the following method.
(1) The liquid crystal aligning agent of the present invention is applied to one surface of a substrate provided with a patterned transparent conductive film by an appropriate application method such as a roll coater method, a spin coating method, a printing method, or an ink jet method. Subsequently, the coated surface is formed by heating the coated surface. Here, as the substrate, for example, glass such as float glass or soda glass; a transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, alicyclic polyolefin, or the like can be used. Examples of the transparent conductive film provided on one surface of the substrate include an NESA film (registered trademark of PPG, USA) made of tin oxide (SnO ₂ ), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ), and the like. Can be used. For patterning these transparent conductive films, a photo-etching method or a method using a mask in advance when forming the transparent conductive film is used. When applying the liquid crystal aligning agent, in order to further improve the adhesion between the substrate surface and the transparent conductive film and the coating film, a functional silane compound, a functional titanium compound or the like is applied in advance to the surface of the substrate. It may be left. After application of the liquid crystal aligning agent, preheating (pre-baking) is preferably performed first for the purpose of preventing dripping of the applied aligning agent. The prebaking temperature is preferably 30 to 200 ° C, more preferably 40 to 150 ° C, and particularly preferably 40 to 100 ° C, and the prebaking time is preferably 0.25 to 10 minutes, more preferably 0. .5-5 minutes. And after removing a solvent completely, it is preferable that a heating (post-baking) process is further implemented. This post-bake temperature is preferably 80 to 300 ° C, more preferably 120 to 250 ° C. The post-bake time is preferably 5 to 200 minutes, more preferably 10 to 100 minutes. The liquid crystal aligning agent of the present invention forms a coating film that becomes an alignment film by removing the organic solvent after coating as described above. Is the polymer contained in the liquid crystal aligning agent of the present invention a polyamic acid? Alternatively, in the case of an imidized polymer having both an imide ring structure and an amic acid structure, the film may be further heated after the formation of the coating film so that the dehydration ring-closing reaction proceeds to form a more imidized coating film.
The film thickness of the formed coating film is preferably 0.001-1 μm, more preferably 0.005-0.5 μm.

(2) The coating film formed as described above can be used as it is as a vertical alignment type liquid crystal alignment film as it is. However, for example, nylon, rayon, cotton, etc. The film may be used as a liquid crystal alignment film after being rubbed in a certain direction with a roll around which a cloth made of fibers is wound. Furthermore, a part of the liquid crystal alignment film as shown in, for example, Patent Document 6 (Japanese Patent Laid-Open No. 6-222366) or Patent Document 7 (Japanese Patent Laid-Open No. 6-281937) is applied to the coating film after the rubbing treatment. Or a part of the surface of the liquid crystal alignment film as disclosed in Patent Document 8 (Japanese Patent Laid-Open No. 5-107544) It is obtained by forming a resist film and then rubbing in a direction different from the previous rubbing process and then removing the resist film so that the liquid crystal alignment film has different liquid crystal alignment capabilities in each region. It is possible to improve the visual field characteristics of the liquid crystal display element. When a rubbing process is performed on the coating surface, it may be washed as necessary.

(3) A liquid crystal cell is manufactured by preparing two substrates on which a liquid crystal alignment film is formed as described above, and disposing a liquid crystal between the two substrates. In order to manufacture a liquid crystal cell, the following two methods are mentioned, for example.
The first method is a conventionally known method. First, two substrates are arranged to face each other through a gap (cell gap) so that the respective liquid crystal alignment films are opposed to each other, and the peripheral portions of the two substrates are bonded using a sealant, and the substrate surface and the sealant are bonded. A liquid crystal cell can be manufactured by injecting and filling liquid crystal into the cell gap partitioned by the step, and then sealing the injection hole.
The second method is a method called an ODF (One Drop Fill) method. For example, an ultraviolet light curable sealing material is applied to a predetermined location on one of the two substrates on which the liquid crystal alignment film is formed, and liquid crystal is dropped on the liquid crystal alignment film surface. The other substrate is bonded so as to face each other, and then the entire surface of the substrate is irradiated with ultraviolet light to cure the sealant, whereby a liquid crystal cell can be manufactured. The liquid crystal aligning agent of this invention has the advantage that the liquid crystal display element which does not generate | occur | produce the liquid crystal alignment nonuniformity resulting from a liquid-crystal dripping trace even when manufacturing a VA-type liquid crystal display element by ODF method. This advantage is that the liquid crystal aligning agent of the present invention is synthesized using a diamine containing a specific diamine (1) in addition to at least one selected from the compounds represented by formulas (I) and (II). This is particularly noticeable when the prepared polymer is contained.
In both cases of the above first and second methods, the liquid crystal cell is then heated to a temperature at which the liquid crystal used takes an isotropic phase, and then slowly cooled to room temperature, so that the flow alignment at the time of filling the liquid crystal is achieved. It is desirable to remove.
And the liquid crystal display element of this invention can be obtained by bonding a polarizing plate on the outer surface of a liquid crystal cell.
Here, as the sealing agent, for example, an epoxy resin containing a curing agent and aluminum oxide spheres as a spacer can be used. Examples of the liquid crystal include nematic liquid crystal and smectic liquid crystal. Among them, nematic liquid crystal is preferable. For example, Schiff base liquid crystal, azoxy liquid crystal, biphenyl liquid crystal, phenyl cyclohexane liquid crystal, ester liquid crystal, terphenyl liquid crystal. Liquid crystals, biphenylcyclohexane liquid crystals, pyrimidine liquid crystals, dioxane liquid crystals, bicyclooctane liquid crystals, cubane liquid crystals, and the like can be used. In addition, cholesteric liquid crystals such as cholestyl chloride, cholesteryl nonate, and cholesteryl carbonate; chiral products such as those sold under the trade names “C-15” and “CB-15” (manufactured by Merck) An agent may be added and used.
As a polarizing plate bonded to the outer surface of the liquid crystal cell, a polarizing film or an H film in which a polarizing film called an “H film” that absorbs iodine while stretching and aligning polyvinyl alcohol is sandwiched between protective films of cellulose acetate The polarizing plate which consists of itself can be mentioned.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. In the following synthesis examples, the solution viscosity of the polymer and the imidization rate of the imidized polymer were evaluated by the following methods, respectively.
[Solution viscosity of polymer]
The solution viscosity of the polymer is a value measured at 25 ° C. using an E-type viscometer for the polymer solution indicated in each synthesis example.
[Imidation rate of imidized polymer]
After the imidized polymer was dried under reduced pressure at room temperature, it was dissolved in deuterated dimethyl sulfoxide, and ¹ H-NMR was measured at room temperature using tetramethylsilane as a reference substance, which was determined by the formula shown by the following formula (i). .

Imidation ratio (%) = (1−A1 / A2 × α) × 100 (i)

A1: Peak area derived from protons of NH group appearing near 10 ppm A2: Peak area derived from other protons α: Number ratio of other protons to one proton of NH group in polymer precursor (polyamic acid)

<Synthesis of Diamine Represented by Formula (I) or (II)>
Each of the following synthesis examples ensured the required amount of product in the following synthesis examples by repeating at the following synthesis scale as necessary.
Synthesis Example 1 (Synthesis of 1 (2,4-diaminophenoxy) -4 (4 (4-n-pentylcyclohexyl) cyclohexyl) benzene)
Scheme 1 below

1 (2,4-diaminophenoxy) -4 (4 (4-n-pentylcyclohexyl) cyclohexyl) benzene (hereinafter also referred to as “diamine A”) was synthesized.
Under a nitrogen atmosphere, 20.3 g (0.1 mol) of 1-chloro-2,4-dinitrobenzene, 32.9 g (0.1 mol) of 4 (4 (4-n-pentylcyclohexyl) cyclohexyl) phenol and potassium carbonate 41.4 g (0.3 mol) was dissolved in 500 mL of dimethylformamide and reacted at room temperature for 6 hours. Distilled water (500 mL) was added to the reaction solution and stirred sufficiently, followed by extraction with chloroform (500 mL), and the resulting organic layer was extracted and washed with distilled water. The organic layer after washing was dehydrated with magnesium sulfate, and the solvent was removed with a rotary evaporator to obtain 47.0 g of 1 (2,4-dinitrophenoxy) -4 (4 (4-n-pentylcyclohexyl) cyclohexyl) benzene. .
Next, in a nitrogen atmosphere, 24.8 g (0.05 mol) of 1 (2,4-dinitrophenoxy) -4 (4 (4-n-pentylcyclohexyl) cyclohexyl) benzene was added to palladium / carbon (Pd / C ) 18.2 g and tetrahydrofuran (300 mL) were added, and the mixture was stirred at 70 ° C. for 1 hour. To this mixture, 30 mL of hydrazine monohydrate was added, and the reaction was performed by stirring at 80 ° C. for 3 hours under nitrogen. After completion of the reaction, the catalyst was filtered off, the filtrate was concentrated, and 300 mL of chloroform was further added to dissolve the whole amount, and then the organic solvent layer was extracted and washed with distilled water. The organic solvent layer was dehydrated with magnesium sulfate and then concentrated with a rotary evaporator to obtain a crude product of diamine A. This crude product was purified by column chromatography, and further the solvent was removed to obtain 18.1 g of diamine A.
Synthesis Example 2 (Synthesis of 3,5-diaminobenzoic acid 4 (4 (4-n-pentylcyclohexyl) cyclohexyl) phenyl)
Scheme 2 below

4, 4- (4- (4-n-pentylcyclohexyl) cyclohexyl) phenyl (hereinafter also referred to as “diamine B”) was synthesized.
Under a nitrogen atmosphere, 32.9 g (0.1 mol) of 4 (4 (4-n-pentylcyclohexyl) cyclohexyl) phenol, 10.6 g (0.105 mol) of triethylamine and 300 mL of tetrahydrofuran were mixed and stirred at 0 ° C. Dissolved. To this solution, a mixed liquid of 21.8 g (0.105 mol) of 3,5-dinitrobenzoyl chloride and 100 mL of tetrahydrofuran was dropped over 30 minutes, and the reaction was further performed by stirring at room temperature for 3 hours. After the precipitated salt was filtered off, the filtrate was concentrated, and further 300 mL of chloroform was added to dissolve the whole amount, followed by extraction washing with distilled water. The organic layer was dehydrated with magnesium sulfate and then concentrated with a rotary evaporator. The obtained crude product was purified by column chromatography and further the solvent was removed to obtain 51.2 g of 3,5-dinitrobenzoic acid 4 (4 (4-n-pentylcyclohexyl) cyclohexyl) phenyl.
Next, 112.8 g of tin chloride dihydrate was added to 26.1 g (0.05 mol) of the above 3,5-dinitrobenzoic acid 4 (4 (4-n-pentylcyclohexyl) cyclohexyl) phenyl in a nitrogen atmosphere. 0.5 mol) and 400 mL of ethyl acetate were added, and the reaction was performed by heating under reflux for 3 hours. After completion of the reaction, the reaction solution was mixed with 400 mL of saturated aqueous potassium fluoride solution, sufficiently stirred and then separated, and the resulting organic layer was extracted and washed with distilled water. Next, the organic layer was dehydrated with magnesium sulfate, concentrated with a rotary evaporator, further purified by column chromatography, and then the solvent was removed to obtain 17.4 g of diamine B.
Synthesis example 3
According to the method described in Patent Document 2 (Japanese Patent Laid-Open No. 09-278724), the following formula

Diamine C represented by
Synthesis example 4
A compound represented by the above formula (D-5) (hereinafter referred to as “compound (D-5)”) was synthesized according to the method described in Patent Document 9 (Japanese Patent Laid-Open No. 4-281427).
<Synthesis of imidized polymer>
Synthesis example 5
2. 12.5 g (0.05 mol) of 3,5,6-tricarboxy-2-carboxynorbornane-2: 3,5: 6-dianhydride as tetracarboxylic dianhydride and p-phenylenediamine as diamine. 2 g (0.03 mol) and 8.7 g (0.02 mol) of diamine A synthesized in Synthesis Example 1 were dissolved in 98 g of N-methyl-2-pyrrolidone (NMP) and reacted at 60 ° C. for 6 hours. It was. A small amount of the obtained polyamic acid solution was taken, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 51 mPa · s.
Next, 120 g of NMP was added to the obtained polyamic acid solution, 20 g of pyridine and 20 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration ring closure reaction, the solvent in the system was replaced with new γ-butyrolactone (by this solvent replacement operation, pyridine and acetic anhydride used in the dehydration ring closure reaction were removed from the system. The same applies hereinafter). About 170 g of a solution containing an imidized polymer (A-1) having an imidization ratio of about 90% was obtained. With respect to this solution, the solution viscosity measured as a γ-butyrolactone solution having a polymer concentration of 10% by weight was 62 mPa · s.
Synthesis Example 6
2. 12.5 g (0.05 mol) of 3,5,6-tricarboxy-2-carboxynorbornane-2: 3,5: 6-dianhydride as tetracarboxylic dianhydride and p-phenylenediamine as diamine. 2 g (0.03 mol) and 9.2 g (0.02 mol) of diamine B were dissolved in 98 g of NMP and reacted at 60 ° C. for 6 hours. A small amount of the obtained polyamic acid solution was collected, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 61 mPa · s.
Next, 120 g of NMP was added to the obtained polyamic acid solution, 20 g of pyridine and 20 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration cyclization reaction, the solvent in the system was replaced with new γ-butyrolactone to obtain about 160 g of a solution containing an imidized polymer (A-2) having an imidization ratio of about 90%. With respect to this solution, the solution viscosity measured as a γ-butyrolactone solution having a polymer concentration of 10% by weight was 71 mPa · s.

Synthesis example 7
2,3,5-Tricarboxycyclopentylacetic acid dianhydride 11 g (0.05 mol) as tetracarboxylic dianhydride and p-phenylenediamine 3.2 g (0.03 mol) and diamine A 8.7 g (diamine) 0.02 mol) was dissolved in 93 g of NMP and reacted at 60 ° C. for 6 hours. A small amount of the obtained polyamic acid solution was collected, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 48 mPa · s.
Next, 120 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, 20 g of pyridine and 20 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with new γ-butyrolactone to obtain about 160 g of a solution containing an imidized polymer (A-3) having an imidization ratio of about 90%. With respect to this solution, the solution viscosity measured as a γ-butyrolactone solution having a polymer concentration of 10% by weight was 58 mPa · s.
Synthesis example 8
12.5 g (0.05 mol) of 3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-dianhydride as tetracarboxylic dianhydride and p-phenylenediamine 3 as diamine .2 g (0.03 mol), 6.5 g (0.015 mol) of diamine A and 2.6 g (0.005 mol) of compound (D-5) are dissolved in 100 g of NMP and reacted at 60 ° C. for 6 hours. It was. A small amount of the obtained polyamic acid solution was collected, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 47 mPa · s.
Next, 124 g of NMP was added to the obtained polyamic acid solution, 20 g of pyridine and 20 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration cyclization reaction, the solvent in the system was replaced with new γ-butyrolactone to obtain about 180 g of a solution containing an imidized polymer (A-4) having an imidization ratio of about 90%. With respect to this solution, the solution viscosity measured as a γ-butyrolactone solution having a polymer concentration of 10% by weight was 57 mPa · s.

Synthesis Example 9
12.5 g (0.05 mol) of 3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-dianhydride as tetracarboxylic dianhydride and p-phenylenediamine 3 as diamine 0.2 g (0.03 mol), diamine B 6.9 g (0.015 mol) and compound (D-5) 2.6 g (0.005 mol) were dissolved in NMP 101 g and reacted at 60 ° C. for 6 hours. It was. A small amount of the obtained polyamic acid solution was collected, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 46 mPa · s.
Subsequently, 126 g of NMP was added to the obtained polyamic acid solution, 20 g of pyridine and 20 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration cyclization reaction, the solvent in the system was replaced with new γ-butyrolactone to obtain about 185 g of a solution containing an imidized polymer (A-5) having an imidization ratio of about 90%. With respect to this solution, the solution viscosity measured as a γ-butyrolactone solution having a polymer concentration of 10% by weight was 56 mPa · s.
Synthesis Example 10
11.2 g (0.05 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride, 3.2 g (0.03 mol) of p-phenylenediamine as diamine, and diamine A 6. 5 g (0.015 mol) and 2.6 g (0.005 mol) of the compound (D-5) were dissolved in 94 g of NMP and reacted at 60 ° C. for 6 hours. A small amount of the obtained polyamic acid solution was collected, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 45 mPa · s.
Next, 118 g of NMP was added to the obtained polyamic acid solution, 20 g of pyridine and 20 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with new γ-butyrolactone to obtain about 180 g of a solution containing an imidized polymer (A-6) having an imidization ratio of about 90%. With respect to this solution, the solution viscosity measured as a γ-butyrolactone solution having a polymer concentration of 10% by weight was 58 mPa · s.

Synthesis Example 11
12.5 g (0.05 mol) of 3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-dianhydride as tetracarboxylic dianhydride and p-phenylenediamine 3 as diamine .2 g (0.03 mol), 6.5 g (0.015 mol) of diamine A and 2.6 g (0.005 mol) of compound (D-5) are dissolved in 100 g of NMP and reacted at 60 ° C. for 6 hours. It was. A small amount of the obtained polyamic acid solution was taken, and the viscosity of the solution measured as a solution having a polyamic acid concentration of 10% by weight by adding NMP was 47 mPa · s. 4 g of pyridine and 5.1 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with new γ-butyrolactone to obtain about 170 g of a solution containing an imidized polymer (A-7) having an imidization ratio of about 45%. With respect to this solution, the solution viscosity measured as a γ-butyrolactone solution having a polymer concentration of 10% by weight was 63 mPa · s.

<Synthesis of other polymers>
(Synthesis of other imidized polymers)
Synthesis Example 12
125 g (0.5 mol) of 3,5,6-tricarboxy-2-carboxynorbornane-2: 3,5: 6-dianhydride as tetracarboxylic dianhydride and 32 g (0. 3 mol) and 70 g (0.2 mol) of diamine C were dissolved in 910 g of NMP and reacted at 60 ° C. for 6 hours. A small amount of the obtained polyamic acid solution was collected, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 55 mPa · s.
Next, 1,100 g of NMP was added to the obtained polyamic acid solution, 200 g of pyridine and 200 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with new γ-butyrolactone to obtain about 1,600 g of a solution containing an imidized polymer (A-8) having an imidization ratio of about 90%. With respect to this solution, the solution viscosity measured as a γ-butyrolactone solution having a polymer concentration of 10% by weight was 65 mPa · s.

Synthesis Example 13
12.5 g (0.05 mol) of 3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-dianhydride as tetracarboxylic dianhydride and p-phenylenediamine 4 as diamine 0.3 g (0.04 mol) and 5.2 g (0.01 mol) of compound (D-5) were dissolved in 88 g of NMP and reacted at 60 ° C. for 6 hours. A small amount of the obtained polyamic acid solution was collected, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 45 mPa · s.
Next, 110 g of NMP was added to the obtained polyamic acid solution, 20 g of pyridine and 20 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with new γ-butyrolactone to obtain about 170 g of a solution containing an imidized polymer (A-9) having an imidization ratio of about 90%. With respect to this solution, the solution viscosity measured as a γ-butyrolactone solution having a polymer concentration of 10% by weight was 55 mPa · s.
(Synthesis of other polyamic acids)
Synthesis Example 14
Pyromellitic dianhydride 55 g (0.25 mol) and 1,2,3,4-cyclobutanetetracarboxylic dianhydride 49 g (0.25 mol) as tetracarboxylic dianhydride and p-phenylenediamine as diamine 54 g (0.5 mol) was dissolved in 630 g of NMP and reacted at 60 ° C. for 6 hours to obtain about 1,200 g of a solution containing 20% by weight of polyamic acid (B-1). A small amount of this polyamic acid solution was taken, NMP was added, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 70 mPa · s.

Example 1 (Reference Example)
<Preparation of liquid crystal aligning agent>
The solution containing the imidized polymer (A-1) obtained in Synthesis Example 5 and the solution containing the polyamic acid (B-1) obtained in Synthesis Example 14 are contained in each solution. The polymer was mixed so that the weight ratio of (A-1) :( B-1) = 80: 20, and γ-butyrolactone, NMP and butyl cellosolve were added thereto, and the solvent composition was γ-butyrolactone: NMP: butyl cellosolve. = 71:17:12 (weight ratio), solid content concentration 2.5% wt% solution. A liquid crystal aligning agent (S-1) was prepared by filtering this solution using a filter having a pore diameter of 1 μm. Table 1 shows the average imidization ratio of the polymer contained in the liquid crystal aligning agent.
<Manufacture of vertical alignment type liquid crystal cell>
The liquid crystal aligning agent (S-1) is applied to the transparent electrode surface of a glass substrate with a transparent electrode made of an ITO film by spin coating, prebaked on an 80 ° C. hot plate for 1 minute, and then a 200 ° C. hot plate. The film was post-baked for 10 minutes to form a coating film (liquid crystal alignment film) having an average film thickness of 60 nm. This operation was repeated to produce a pair (two) of substrates having a liquid crystal alignment film on the transparent electrode surface.
Substrate with a liquid crystal alignment film The epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm is applied to the outer edges of each pair of liquid crystal alignment films, and then the liquid crystal alignment films are stacked and pressure-bonded to face each other. The adhesive was cured. Next, a negative type liquid crystal (MLC-6608, manufactured by Merck & Co., Inc.) is filled between the pair of substrates from the liquid crystal injection port, and then the liquid crystal injection port is sealed with an acrylic photo-curing adhesive, whereby a vertical alignment type liquid crystal A cell was manufactured. The liquid crystal cell was evaluated for voltage holding ratio and afterimage characteristics as follows. The evaluation results are shown in Table 1.

<Evaluation of voltage holding ratio>
A voltage of 1 V was applied to the vertical alignment type liquid crystal cell at 65 ° C. with an application time of 60 microseconds and a span of 167 milliseconds, and then the voltage holding ratio after 167 milliseconds from release of application was measured. As a measuring device, VHR-1 manufactured by Toyo Corporation was used.
<Evaluation of afterimage characteristics>
A vertical alignment type liquid crystal cell was manufactured in the same manner as in the above <Manufacture of vertical alignment type liquid crystal cell> except that a glass substrate having two ITO transparent electrodes with a pattern as shown in FIG. 1 was used as the substrate.
A direct current voltage of 6.0 V and 0.5 V were simultaneously applied to the electrode A and the electrode B for 168 hours while irradiating backlight light to the liquid crystal cell in an environment of 40 to 50 ° C. After releasing the stress, a DC voltage of 0.1 to 5.0 V was applied to the electrodes A and B in increments of 0.1 V, and the afterimage characteristics were determined based on the luminance difference between the electrodes A and B at the respective voltages. The case where no difference in luminance was recognized was determined to be an afterimage characteristic “excellent”, the case where the luminance difference was small was determined to be “good”, and the case where the luminance difference was large was determined to be “bad”.
Examples 2-12 and Comparative Examples 1-3 (Examples 2-5 are reference examples)
Liquid crystal aligning agents (S-2) to (S-12) and (R-1) to (R-3) were prepared in the same manner as in Example 1, except that the polymer composition described in Table 1 was followed. A liquid crystal cell was manufactured and evaluated. The evaluation results are shown in Table 1.
In Table 1, the numerical value in parentheses after the polymer type name is the amount (part by weight) of the polymer contained in the polymer solution used. In Examples 9 to 11 and Comparative Example 3, No acid solution was used.

Example 13
<Evaluation of liquid crystal alignment unevenness characteristics>
The liquid crystal aligning agent (S-6) prepared in Example 6 above was applied to the transparent electrode surface of a glass substrate with a transparent electrode made of an ITO film by spin coating, and prebaked for 1 minute on an 80 ° C. hot plate. The film was post-baked for 10 minutes on a hot plate at 200 ° C. to form a coating film (liquid crystal alignment film) having an average film thickness of 60 nm. This operation was repeated to produce a pair (two) of substrates having a liquid crystal alignment film on the transparent electrode surface.
A micropipette was used to drop 5 μL of ultrapure water droplets on a surface of one of the substrates having the liquid crystal alignment film produced above using a micropipette, and the mixture was naturally dried at room temperature. .
As described above, a vertical alignment type liquid crystal cell was manufactured in the same manner as in Example 1 except that a pair of substrates including a substrate subjected to an impact by dropping a liquid crystal on the liquid crystal alignment film surface was used.
When this liquid crystal cell was observed under crossed Nicols while applying a rectangular wave of AC 6.0 V (peak-peak) and 30 Hz at room temperature, the ultrapure water dripping marks were not visually recognized as liquid crystal alignment unevenness. The case where the liquid crystal alignment unevenness characteristic “excellent” was evaluated, the liquid crystal alignment unevenness characteristic “good” when the liquid crystal alignment unevenness characteristic was slightly recognized, and the liquid crystal alignment unevenness characteristic “bad” when it was clearly visible were evaluated. The results are shown in Table 2.
In addition, the dripping of ultrapure water in the above is an alternative evaluation for investigating the impact of liquid crystal dripping in the ODF process.
Examples 14-19 and Comparative Examples 4 and 5
As a liquid crystal aligning agent, a pair of substrates including a substrate subjected to an impact caused by dropping of ultrapure water on the liquid crystal aligning film surface in the same manner as in Example 13 except that those listed in Table 2 were used. A vertical alignment type liquid crystal cell was manufactured using the liquid crystal, and liquid crystal alignment unevenness characteristics were evaluated. The results are shown in Table 2.

Claims (6)

A liquid crystal aligning agent comprising at least one polymer selected from the group consisting of polyamic acid obtained by reacting tetracarboxylic dianhydride and diamine and an imidized polymer thereof,
The diamine is
The following formula (I) or (II)

(In the above formula, n1 is each independently an integer of 1 to 8.)
A compound represented in,
The following formulas (D-I) and (D-II)

(In the formula ( DI ), X ¹ represents a divalent organic group selected from —O—, —COO—, —OCO—, —NHCO—, —CONH— and —CO—, and R ⁵ represents a steroid. A monovalent organic group having a skeleton, R ⁶ represents an alkyl group having 1 to 4 carbon atoms, a1 represents an integer of 0 to 3,
In formula (D-II), X ² represents a divalent organic group selected from —O—, —COO—, —OCO—, —NHCO—, —CONH—, and —CO—, respectively, and R ⁷ Represents a divalent organic group having a steroid skeleton, R ⁸ represents an alkyl group having 1 to 4 carbon atoms, and a2 represents an integer of 0 to 3, respectively. )
Monodea Rukoto and wherein said liquid crystal alignment agent containing at least one and <br/> selected from compounds represented by formulas. Tetracarboxylic dianhydride, 3,5,6-tricarboxy-2-carboxymethyl norbornane -2: 3,5: in which 6-containing dianhydride, liquid crystal aligning agent of claim 1. From the group consisting of a polyamic acid obtained by reacting tetracarboxylic dianhydride with a diamine not containing any of the compounds represented by formulas (I) and (II) and an imidized polymer thereof. The liquid crystal aligning agent of Claim 1 or 2 which further contains the at least 1 sort (s) of polymer chosen. The number of amic acid structures possessed by the polyamic acid contained in the liquid crystal aligning agent and the ratio of the number of amic acid structures possessed by the imidized polymer and the number of imide rings possessed by the imidized polymer relative to the total number of imide rings The liquid crystal aligning agent as described in any one of Claims 1-3 whose is 40% or more. Characterized in that it is used in the formation of the vertical alignment type liquid crystal alignment film of the liquid crystal alignment agent according to any one of claims 1-4. Characterized by comprising a liquid crystal alignment film formed from the liquid crystal alignment agent according to any one of claims 1 to 5 liquid crystal display device.

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