JP6492688B2 - Liquid crystal aligning agent, liquid crystal aligning film, manufacturing method thereof, and liquid crystal display element - Google Patents

Description

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

  In recent years, liquid crystal display elements are used not only for display terminals such as personal computers as in the past, but also for various applications such as liquid crystal televisions, car navigation systems, mobile phones, smartphones, and information displays. In addition, as liquid crystal display elements, further improvement in display quality has been demanded as versatility has been achieved, and various liquid crystal aligning agents have been provided to satisfy these requirements (for example, Patent Documents 1 to 3). reference).

  Patent Documents 1 to 3 disclose that a polyamic acid obtained by reacting a diamine having a piperazine ring with tetracarboxylic dianhydride or a derivative thereof is used as a polymer component of a liquid crystal aligning agent. Specifically, Patent Document 1 discloses that an aromatic diamine having a partial structure of “-benzene ring-piperazine ring-benzene ring-” is used as a monomer, and Patent Document 3 discloses “-alkylene chain”. It is disclosed that a diamine having a partial structure of “piperazine ring-alkylene chain-” is used as a monomer. Attempts have been made to obtain a liquid crystal alignment film having an appropriate ion density and long-term reliability by using such a diamine. Patent Document 2 discloses that the liquid crystal aligning agent contains a polyimide obtained by polymerization using a diamine having a piperazine ring as a monomer, thereby improving the heat resistance and the voltage leakage of the liquid crystal alignment film. Has been.

JP 2009-175684 A JP 2010-2501 A JP 2011-28223 A

  In order to improve display quality, various properties are required for the liquid crystal alignment film. Examples of important properties include, for example, liquid crystal alignment, difficulty in generating afterimage (afterimage characteristics), and reliability. In particular, reliability is withstood even when used in harsh environments such as long-term continuous driving, thermal stress, and light stress as liquid crystal display devices become more versatile. Is important to get. Liquid crystal display elements are required to further improve these various characteristics in order to further improve quality.

  The present invention has been made in view of the above problems, and provides a liquid crystal aligning agent that can form a coating film with good liquid crystal orientation and can obtain a liquid crystal display element with good reliability and afterimage characteristics. The main purpose is to provide.

  As a result of intensive studies to achieve the above-described problems of the prior art, the present inventors include a polymer having a specific partial structure containing nitrogen atoms in the main chain as the polymer component of the liquid crystal aligning agent. Thus, the present inventors have found that the above problems can be solved, and have completed the present invention. Specifically, the present invention provides the following liquid crystal aligning agent, liquid crystal aligning film, method for producing the liquid crystal aligning film, and liquid crystal display element.

  In one aspect, the present invention provides a liquid crystal aligning agent containing a polymer (P) having a partial structure represented by the following formula (1) in the main chain.

（式（１）中、Ｘ^１は２価の有機基であり、Ｙ^１は、２価の連結基又は単結合である。ただし、２個のＸ^１の少なくとも一方は２価の芳香族複素環基であり、２個のＸ^１の一方のみが２価の芳香族複素環基である場合、Ｙ^１は１個以上の窒素原子を有する２価の連結基であって且つ２個のＸ^１はＹ^１中の同一の又は異なる窒素原子に結合している。２個のＸ^１は同じでも異なっていてもよい。「＊」は結合手を示す。）

(In Formula (1), X ¹ is a divalent organic group, and Y ¹ is a divalent linking group or a single bond. However, at least one of the two X ¹ is a divalent aromatic complex. a Hajime Tamaki, the two cases only one of X ¹ is a divalent aromatic heterocyclic group, Y ¹ is a divalent linking group having one or more nitrogen atoms and two X ¹ is bonded to the same or different nitrogen atom in Y ^1. Two X ¹ may be the same or different. “*” Represents a bond.)

  In one aspect, the present invention provides a liquid crystal alignment film comprising a step of applying the liquid crystal alignment agent on a substrate to form a coating film, and a step of irradiating the coating film with light to impart liquid crystal alignment ability. Provided is a method for producing a liquid crystal alignment film comprising a production method and a step of forming a coating film using the liquid crystal alignment agent and a step of rubbing the coating film to impart liquid crystal alignment ability. Moreover, the liquid crystal aligning film formed with the said liquid crystal aligning agent and the liquid crystal display element which comprises this liquid crystal aligning film are provided.

  In another aspect, the present invention is a polymer having at least one selected from the group consisting of polyamic acid, polyamic acid ester and polyimide and having a partial structure represented by the above formula (1) in the main chain. provide.

（式（３）中、Ｘ^１は２価の有機基であり、ただし、２個のＸ^１の少なくとも一方は２価の芳香族複素環基である。Ｚ^１は１級アミノ基又は下記式（ｚ−１）

（式（ｚ−１）中、「＊」はＸ^１との結合手を示す。）
で表される基である。Ｒ^１は、単結合、炭素数１〜６のアルカンジイル基又はシクロヘキシレン基であり、Ｒ^２は、水素原子若しくは炭素数１〜６のアルキル基であるか、又は２個のＲ^２が互いに結合して２個の窒素原子及びＲ^１と共に炭素数２〜１０の２価の脂環式複素環基を形成する。２個のＸ^１は同じでも異なっていてもよく、２個のＲ^２は同じでも異なっていてもよい。ｐは０又は１である。） In another aspect, the present invention provides a compound represented by the following formula (3).

(In Formula (3), X ¹ is a divalent organic group, provided that at least one of the two X ¹ is a divalent aromatic heterocyclic group. Z ¹ is a primary amino group or the following formula: (Z-1)

(In the formula (z-1), "*" indicates a bond to ^{X 1.)}
It is group represented by these. R ¹ is a single bond, an alkanediyl group having 1 to 6 carbon atoms or a cyclohexylene group, R ² is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, or two R ² are mutually bonded It combines to form a divalent alicyclic heterocyclic group having 2 to 10 carbon atoms together with two nitrogen atoms and R ¹ . Two X ¹ may be the same or different, and two R ² may be the same or different. p is 0 or 1. )

  According to the liquid crystal aligning agent of the present invention, it is possible to form a coating film with good liquid crystal alignment by including a polymer having a specific structure in at least a part of the polymer component, and reliability and A liquid crystal display element having excellent afterimage characteristics can be obtained.

  Below, each component contained in the liquid crystal aligning agent of this invention and the other component arbitrarily mix | blended as needed are demonstrated.

（式（１）中、Ｘ^１は２価の有機基であり、Ｙ^１は、２価の連結基又は単結合である。ただし、２個のＸ^１の少なくとも一方は２価の芳香族複素環基であり、２個のＸ^１の一方のみが２価の芳香族複素環基である場合、Ｙ^１は１個以上の窒素原子を有する２価の連結基であって且つ２個のＸ^１はＹ^１中の同一の又は異なる窒素原子に結合している。２個のＸ^１は同じでも異なっていてもよい。「＊」は結合手を示す。） <Polymer (P)>
The liquid crystal aligning agent of this invention contains the polymer (P) which has a structure represented by following formula (1) in a principal chain as at least one component of a polymer component.

(In Formula (1), X ¹ is a divalent organic group, and Y ¹ is a divalent linking group or a single bond. However, at least one of the two X ¹ is a divalent aromatic complex. a Hajime Tamaki, the two cases only one of X ¹ is a divalent aromatic heterocyclic group, Y ¹ is a divalent linking group having one or more nitrogen atoms and two X ¹ is bonded to the same or different nitrogen atom in Y ^1. Two X ¹ may be the same or different. “*” Represents a bond.)

The divalent aromatic heterocyclic group represented by X ¹ in the above formula (1) is a group obtained by removing two hydrogen atoms from atoms constituting the ring of the aromatic heterocyclic ring, and a substituent is introduced into the ring portion. It may be. The ring portion of X ¹ is preferably a nitrogen atom-containing aromatic heterocyclic ring, and specific examples thereof include, for example, pyrrole, imidazole, pyrazole, triazole, pyridine, pyrimidine, pyridazine, pyrazine, indole, benzimidazole, purine Quinoline, isoquinoline, naphthyridine, quinoxaline, phthalazine, triazine, azepine, diazepine, acridine, phenazine, phenanthroline, oxazole, thiazole, carbazole, thiadiazole, benzothiazole, phenothiazine, oxadiazole and the like.
Examples of the substituent that may be introduced into the ring portion of the aromatic heterocyclic group represented by X ¹ include halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom; methyl group, ethyl group, propyl group and the like Examples thereof include a linear or branched alkyl group having 1 to 6 carbon atoms; an alkoxy group having 1 to 6 carbon atoms such as a methoxy group, an ethoxy group, and a propoxy group.

The ring skeleton having an aromatic heterocyclic group of the above X ^1, synthesis ease of monomers, from the viewpoint of seizure reduction and reliable liquid crystal display device, pyrrole among the above-mentioned, imidazole, pyrazole, pyridine, pyrimidine, pyridazine Pyrazine or triazine is preferable, and pyridine, pyrimidine or pyrazine is more preferable. The two bonds in X ¹ are preferably in the 1,4-position with respect to other groups.

Examples of the divalent organic group for X ¹ include a divalent chain hydrocarbon group, a divalent alicyclic hydrocarbon group, and a divalent aromatic hydrocarbon group. Among these, from the viewpoint of improving the reliability and afterimage characteristics of the liquid crystal display element, a divalent aromatic hydrocarbon group is preferable, and specific examples include, for example, a phenylene group, a biphenylene group, and a naphthylene group. Can be mentioned. Preferably, it is a phenylene group or a biphenylene group.
The two X ¹ in the formula (1) are preferably both divalent aromatic heterocyclic groups from the viewpoint of high image sticking reduction and reliability improvement effects of the liquid crystal display element.

Specific examples of the divalent linking group for Y ¹ include, for example, —O—, —CO—, —COO—, —NR ^a —, —CONR ^a —, —NR ^a CONR ^a — (where R ^a is A hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms.), A divalent functional group such as —N═N—, —COS—, —S—; a divalent chain hydrocarbon group, a divalent A divalent hydrocarbon group such as an alicyclic hydrocarbon group and a divalent aromatic hydrocarbon group; a group obtained by replacing at least one methylene group in the divalent hydrocarbon group with the above divalent functional group; A divalent group having a heterocyclic ring, and the like.
Here, the “chain hydrocarbon group” in the present specification means a linear hydrocarbon group and a branched hydrocarbon group which are composed only of a chain structure without including a cyclic structure in the main chain. However, it may be saturated or unsaturated. The “alicyclic hydrocarbon group” means a hydrocarbon group that includes only an alicyclic hydrocarbon structure as a ring structure and does not include an aromatic ring structure. However, it is not necessary to be comprised only by the structure of alicyclic hydrocarbon, and what has a chain structure in the part is also included. “Aromatic hydrocarbon group” means a hydrocarbon group containing an aromatic ring structure as a ring structure. However, it is not necessary to be composed only of an aromatic ring structure, and a part thereof may include a chain structure or an alicyclic hydrocarbon structure.

The divalent linking group for Y ¹ is preferably a group having at least one nitrogen atom, and preferably a group having two or more nitrogen atoms, from the viewpoint of reduction in image sticking and reliability of the liquid crystal display element. It is more preferable. The upper limit of the number of nitrogen atoms that Y ¹ has is not particularly limited, but is preferably 4 or less, more preferably 3 or less.
When Y ¹ is a divalent organic group having one or more nitrogen atoms, each of the two X ¹ is preferably bonded to the nitrogen atom in Y ¹ . When Y ¹ is a divalent linking group having two or more nitrogen atoms, two X ^{1 s} may be bonded to the same nitrogen atom in Y ^{1 or} bonded to different nitrogen atoms. However, it is preferably bonded to different nitrogen atoms in Y ¹ . When only one of the two X ¹ is a divalent aromatic heterocyclic group, Y ¹ becomes a divalent linking group having one or more nitrogen atoms. In this case, two X ¹ in the above formula (1) are bonded to the same or different nitrogen atoms in Y ¹ .

（式（Ｙ−１）中、Ｒ^１は、単結合、炭素数１〜６のアルカンジイル基又はシクロヘキシレン基であり、Ｒ^２は、水素原子若しくは炭素数１〜６のアルキル基であるか、又は２個のＲ^２が互いに結合して２個の窒素原子及びＲ^１と共に炭素数２〜１０の２価の脂環式複素環基を形成する。２個のＲ^２は同じでも異なっていてもよい。ｐは０又は１である。「＊」はＸ^１との結合手を示す。） Specific examples of particularly preferred Y ¹ include a group represented by the following formula (Y-1).

(In Formula (Y-1), R ¹ is a single bond, an alkanediyl group having 1 to 6 carbon atoms or a cyclohexylene group, and is R ² a hydrogen atom or an alkyl group having 1 to 6 carbon atoms? Or two R ² are bonded to each other to form a divalent alicyclic heterocyclic group having 2 to 10 carbon atoms together with two nitrogen atoms and R ^{1. The} two R ² are the same or different. P is 0 or 1. “*” indicates a bond to X ¹ )

Examples of the alkanediyl group having 1 to 6 carbon atoms of R ¹ in the formula (Y-1) include a methylene group, an ethylene group, a propanediyl group, a butanediyl group, a pentanediyl group, and a hexanediyl group. It may be linear or branched. R ¹ is preferably an alkanediyl group having 1 to 6 carbon atoms, and more preferably 1 to 4 carbon atoms. When R ¹ is a cyclohexylene group, it is preferably a 1,4-cyclohexylene group.
Examples of the alkyl group having 1 to 6 carbon atoms of R ² include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group, and these may be linear or branched. The alkyl group preferably has 1 to 4 carbon atoms, more preferably 1 to 3 carbon atoms.
p is 0 or 1, and preferably p = 1 from the viewpoint of improving the reliability and the afterimage characteristics of the liquid crystal display element.

（式（Ｙ−１−１）中、Ｒ^１１は１価の置換基であり、ｋは０〜（ａ＋ｂ）の整数である。ａ及びｂは、ａ＋ｂ≧２を満たす０以上の整数である。「＊」は結合手を示す。） When p = 1, there are two R ^{2 in} the formula (Y-1). The divalent alicyclic heterocyclic group formed by bonding these two R ² to each other is a group obtained by removing two hydrogen atoms from the atoms constituting the ring of the alicyclic heterocyclic ring, Specifically, it can be represented by the following formula (Y-1-1).

(In Formula (Y-1-1), R ¹¹ is a monovalent substituent, k is an integer of 0 to (a + b), and a and b are integers of 0 or more that satisfy a + b ≧ 2. ("*" Indicates a bond)

Examples of R ^{11 in the} formula (Y-1-1) include a halogen atom, an alkyl group having 1 to 6 carbon atoms, and an alkoxy group having 1 to 6 carbon atoms. k is preferably 0.
The alicyclic heterocyclic group represented by the above formula (Y-1-1) preferably has 5 to 12 ring members, and more preferably 5 to 7. A 1,4-piperazinediyl group is particularly preferable in that the rate of relaxation of accumulated charges is high and the effect of reducing afterimages is high.

（式（２）中、Ｘ^１は２価の有機基であり、ただし、２個のＸ^１の少なくとも一方は２価の芳香族複素環基である。Ｒ^１、Ｒ^２及びｐは上記式（Ｙ−１）と同義である。「＊」は結合手を示す。） The structure represented by the above formula (1) is preferably a structure represented by the following formula (2).

(In the formula (2), X ¹ is a divalent organic group, provided that at least one of the two X ¹ is a divalent aromatic heterocyclic group. R ¹ , R ² and p are the above formulas. (It is synonymous with (Y-1). “*” Indicates a bond.)

（式中、「＊」は結合手を示す。） Preferable specific examples of the structure represented by the above formula (1) include, for example, the following formula (2-1-1) to formula (2-1-8), formula (2-2-1) to formula (2- 2-5), Formula (2-3-1) to Formula (2-3-3), Formula (2-4-1) to Formula (2-4-5), Formula (2-5-1) to Examples include structures represented by formula (2-5-6) and formula (2-6-1).

(In the formula, “*” indicates a bond.)

（式中、「＊」は結合手を示す。）

(In the formula, “*” indicates a bond.)

Examples of the main chain of the polymer (P) include a skeleton composed of polyamic acid, polyimide, polyamic acid ester, polyester, polyamide, and the like. In the present specification, the “main chain” of a polymer is a structure formed by repeating bonding of one or more monomers, and refers to the longest “trunk” portion of the polymer. . Therefore, “having the partial structure represented by the above formula (1) in the main chain” means that this structure constitutes a part of the “trunk” of the polymer. However, in the polymer (P), it is excluded that the structure represented by the formula (1) exists also in a portion other than the main chain, for example, a side chain (a portion branched from the “trunk” of the polymer). It is not a thing.
The polymer (P) can be obtained, for example, by a polymerization method using a compound having a structure represented by the above formula (1) as a monomer.

  As said polymer (P), the 1 type (s) or 2 or more types of the polymer selected from these can be selected suitably, and can be used. Especially, it is preferable to make the said polymer (P) into at least 1 type chosen from the group which consists of a polyamic acid, a polyimide, and a polyamic acid ester.

[Polyamic acid (P)]
When the polymer (P) is a polyamic acid (hereinafter also referred to as “polyamic acid (P)”), the polyamic acid (P) is obtained by, for example, reacting a tetracarboxylic dianhydride and a diamine. Can be obtained. Specifically, for example, polymerization is performed using (i) a tetracarboxylic dianhydride having a partial structure represented by the above formula (1) (hereinafter also referred to as “specific tetracarboxylic dianhydride”) as a monomer. (Ii) a method in which a diamine having a partial structure represented by the above formula (1) (hereinafter, also referred to as “specific diamine”) is used as a monomer, and (iii) a specific tetracarboxylic dianhydride. And a method of polymerizing using the specific diamine as a monomer.

（式（３−１ｂ）中、Ｘ^１及びＹ^１は、それぞれ上記式（１）と同義である。） [Tetracarboxylic dianhydride]
(Specific tetracarboxylic dianhydride)
As a specific tetracarboxylic dianhydride used for the synthesis | combination of the said polyamic acid (P), the compound etc. which are represented, for example by a following formula (3-1b) are mentioned.

(In formula (3-1b), X ¹ and Y ¹ are respectively synonymous with the above formula (1).)

The explanation of X ¹ and Y ¹ in the above formula (1) can be applied to X ¹ and Y ^{1 in} the above formula (3-1b), respectively.
Specific examples of the compound represented by the formula (3-1b) include, for example, compounds represented by the following formulas (4-1) to (4-8). In addition, specific tetracarboxylic dianhydride can be used individually by 1 type or in combination of 2 or more types.

（式（３−Ｂ）中、Ｒ^１、Ｒ^２及びｐは上記式（Ｙ−１）と同義であり、Ｘ^１は上記式（２）と同義である。） As the specific tetracarboxylic dianhydride, Y ¹ in the formula (3-1b) is preferably a group represented by the formula (Y-1). Specifically, the following formula (3-B ).

(In the formula (3-B), R ¹ , R ² and p have the same meaning as the above formula (Y-1), and X ¹ has the same meaning as the above formula (2).)

The description of X ¹ in the above formula (1) can be applied to X ^{1 in} the above formula (3-B). Further, for ^{R 1} and ^{R 2} may be applied above formula (Y-1) of ^{R 1} and ^{R 2} described respectively. p is preferably 1.
Specific examples of the compound represented by the formula (3-B) include, for example, each of the formula (4-1) to the formula (4-4), the formula (4-7), and the formula (4-8). The compound etc. which are represented can be mentioned.
The compound represented by the above formula (3-B) can be synthesized by appropriately combining organic chemistry methods. As an example, a reaction between a diamine having a structure represented by the above formula (2) (a compound represented by the following formula (3-A)) and a carboxyl group-containing halide yields the above formula (2). Can be obtained by synthesizing a tetracarboxylic acid having the structure represented by

(Other tetracarboxylic dianhydrides)
As the tetracarboxylic dianhydride used for the synthesis of the polymer (P), the above-mentioned specific tetracarboxylic dianhydride may be used alone, but other tetracarboxylic dianhydrides may be used together with the specific tetracarboxylic dianhydride. Anhydrides may be used.

Examples of the other tetracarboxylic dianhydrides include aliphatic tetracarboxylic dianhydrides, alicyclic tetracarboxylic dianhydrides, and aromatic tetracarboxylic dianhydrides. Specific examples thereof include aliphatic tetracarboxylic dianhydrides such as 1,2,3,4-butanetetracarboxylic dianhydride;
Examples of the alicyclic tetracarboxylic dianhydride 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- No 1,2-dicarboxylic acid 3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-dianhydride, 2,4,6,8-tetracarboxybicyclo [3.3.0] octane-2 : 4,6: 8-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^2,6 ] undecane-3,5,8,10-tetraone, 1,2,4,5 -Cyclohexanetetracarboxylic dianhydride, p-phenylenebis (trimellitic acid monoester anhydride), etc .;
Examples of aromatic tetracarboxylic dianhydrides include pyromellitic dianhydride;
In addition to the above, tetracarboxylic dianhydrides described in JP 2010-97188 A can be used. In addition, tetracarboxylic dianhydride can be used individually by 1 type or in combination of 2 or more types.

  The preferred use ratio of the specific tetracarboxylic dianhydride varies depending on the method of synthesizing the polyamic acid (P). For example, in the case of the above method (i), the use ratio of the specific tetracarboxylic dianhydride is set to 5 mol% or more with respect to the total amount of the tetracarboxylic dianhydride used for the synthesis of the polyamic acid (P). It is preferably 10 mol% or more, more preferably 20 mol% or more. The upper limit of the use ratio is not particularly limited and can be appropriately selected within a range of 100 mol% or less.

（式（３−１ａ）中、Ｘ^１及びＹ^１は上記式（１）と同義である。） [Diamine]
(Specific diamine)
The specific diamine used for the synthesis of the polyamic acid (P) may be any of aliphatic diamine, alicyclic diamine, aromatic diamine, and the like, and specifically, a compound represented by the following formula (3-1a). Preferably there is.

(In Formula (3-1a), X ¹ and Y ¹ have the same meanings as in Formula (1) above.)

For ^{X 1} and ^{Y 1} in the formula (3-1a), it can be applied to the description of ^{X 1} and ^{Y 1} in the formula (1). The specific diamine is preferably an aromatic diamine.
Specific examples of the specific diamine include compounds represented by the following formulas (3-1) to (3-83).

（式（３−Ａ）中、Ｒ^１、Ｒ^２及びｐは上記式（Ｙ−１）と同義であり、上記式Ｘ^１は上記式（２）と同義である。） A preferred specific example of the specific diamine is a compound in which Y ¹ in the formula (3-1a) is a group represented by the formula (Y-1). Specifically, the following formula (3-A) Can be expressed as

(In the formula (3-A), R ¹ , R ² and p have the same meaning as the above formula (Y-1), and the above formula X ¹ has the same meaning as the above formula (2).)

For ^{X 1} in the formula (3-A), it can be applied to the description of ^{X 1} in the formula (1). Further, for ^{R 1} and ^{R 2} may be applied above formula (Y-1) of ^{R 1} and ^{R 2} described respectively. p is preferably 1.
Specific examples of the compound represented by the formula (3-A) include, for example, the formula (3-1) to the formula (3-13), the formula (3-16), the formula (3-19), the formula ( 3-64), a compound represented by each of formula (3-65) and formula (3-68) to formula (3-83).
The compound represented by the above formula (3-A) can be synthesized by appropriately combining organic chemistry methods. As an example, a dinitro intermediate having a nitro group instead of the two primary amino groups in the above formula (3-A) is synthesized, and then the nitro group of the obtained dinitro intermediate is converted into an appropriate reduction system. A method of amination using them is mentioned. The method for synthesizing the dinitro intermediate can be appropriately selected according to the target compound.
As the specific diamine used for the synthesis of the polyamic acid, one kind of these compounds can be used alone or two or more kinds can be appropriately selected and used.

(Other diamines)
As the diamine used for the synthesis of the polymer (P), the specific diamine may be used alone, but other diamines may be used together with the specific diamine.

Examples of the other diamines include aliphatic diamines, alicyclic diamines, aromatic diamines, diaminoorganosiloxanes, and the like. Specific examples thereof include aliphatic diamines such as m-xylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine and the like;
Examples of alicyclic diamines include 1,4-diaminocyclohexane, 4,4′-methylenebis (cyclohexylamine), 1,3-bis (aminomethyl) cyclohexane and the like;

（式（Ａ−１）中、Ｘ^I及びＸ^IIは、それぞれ独立に、単結合、−Ｏ−、−ＣＯＯ−又は−ＯＣＯ−であり、Ｒ^Ｉは炭素数１〜３のアルカンジイル基であり、Ｒ^ＩＩは単結合又は炭素数１〜３のアルカンジイル基である。ａは０又は１であり、ｂは０〜２の整数であり、ｃは１〜２０の整数であり、ｄは０又は１である。但し、ａ及びｂが同時に０になることはない。） Examples of aromatic diamines include o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl sulfide, 4,4′-diaminodiphenylamine, and 4-aminophenyl. -4'-aminobenzoate, 1,7-bis (4-aminophenoxy) heptane, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-bis (trifluoromethyl) -4,4 '-Diaminobiphenyl, 4,4'-diaminodiphenyl ether, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 9,9-bis (4-aminophenyl) fluorene, 2,2-bis [ 4- (4-Aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) Xafluoropropane, 4,4 ′-(p-phenylenediisopropylidene) bisaniline, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, 2,6- Diaminopyridine, N, N′-bis (4-aminophenyl) -benzidine, 3,5-diaminobenzoic acid, dodecanoxy-2,4-diaminobenzene, dodecanoxy-2,5-diaminobenzene, cholestanyloxy-3, 5-diaminobenzene, cholestanyloxy-2,4-diaminobenzene, cholestanyl 3,5-diaminobenzoate, 3,6-bis (4-aminobenzoyloxy) cholestane, 4- (4′-trifluoromethoxybenzoy) Loxy) cyclohexyl-3,5-diaminobenzoate, 2,4-diamino-N, N-diary Aniline, 4-aminobenzylamine, 1- (2,4-diaminophenyl) piperazine-4-carboxylic acid, 1,3-bis (N- (4-aminophenyl) piperidinyl) propane, 1- (4-aminophenyl) ) -2,3-dihydro-1,3,3-trimethyl-1H-indene-5-amine, 1- (4-aminophenyl) -2,3-dihydro-1,3,3-trimethyl-1H-indene -6-amine, 4-aminophenyl-4′-aminobenzoate, 4,4 ′-[4,4′-propane-1,3-diylbis (piperidine-1,4-diyl)] dianiline, and the following formula ( A-1)

(In Formula (A-1), X ^I and X ^II are each independently a single bond, —O—, —COO— or —OCO—, and R ^I is an alkanediyl group having 1 to 3 carbon atoms. R ^II is a single bond or an alkanediyl group having 1 to 3 carbon atoms, a is 0 or 1, b is an integer of 0 to 2, c is an integer of 1 to 20, and d is 0 or 1, provided that a and b are not 0 at the same time.)

A compound represented by:
Examples of the diaminoorganosiloxane include 1,3-bis (3-aminopropyl) -tetramethyldisiloxane; and the diamines described in JP-A 2010-97188 can be used.

Examples of the divalent group represented by “—X ^I — (R ^I —X ^II ) _d —” in formula (A-1) include alkanediyl groups having 1 to 3 carbon atoms, —O—, * — COO— or —O—C ₂ H ₄ —O— (however, a bond marked with “*” is bonded to a diaminophenyl group) is preferred. Specific examples of the group “—C _c H _{2c + 1} ” include, for example, methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group. Group, n-nonyl group, n-decyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, n-nonadecyl group Group, n-eicosyl group and the like. The two amino groups in the diaminophenyl group are preferably in the 2,4-position or 3,5-position with respect to other groups.

Specific examples of the compound represented by the formula (A-1) include compounds represented by the following formulas (A-1-1) to (A-1-4). .

  In addition, as another diamine used for the synthesis | combination of the said polyamic acid, 1 type of these compounds can be used individually or in combination of 2 or more types as appropriate.

  The preferred use ratio of the specific diamine varies depending on the method of synthesizing the polyamic acid (P). For example, in the case of the above method (ii), the use ratio of the specific diamine is preferably 5 mol% or more with respect to the total amount of diamine used for the synthesis of the polyamic acid (P), and is preferably 10 mol% or more. More preferably, it is more preferably 20 mol% or more. The upper limit value of the use ratio is not particularly limited, and can be arbitrarily set within a range of 100 mol% or less depending on various characteristics (for example, pretilt angle characteristics) imparted to the polymer.

When the liquid crystal aligning agent of the present invention is used for production of a TN type, STN type or vertical alignment type liquid crystal display element, at least a part of the polymer (P) contained in the liquid crystal aligning agent is pretilt with respect to the coating film. A polymer having a group capable of imparting an angle development ability (hereinafter also referred to as a “pretilt angle expression group”) may be used. Examples of the pretilt angle-expressing group include an alkyl group having 4 to 20 carbon atoms, a fluoroalkyl group having 4 to 20 carbon atoms, an alkoxy group having 4 to 20 carbon atoms, a group having a steroid skeleton having 17 to 51 carbon atoms, And a group having a ring structure.
For example, the polyamic acid (P) having a pretilt angle-expressing group can be obtained by polymerization containing a diamine having a pretilt angle-expressing group in the monomer composition as the other diamine. When using a diamine having a pretilt angle-expressing group, the amount used may be appropriately set according to the target pretilt angle, but for example, 1 mol% with respect to the total diamine used in the synthesis. It can be set as the above, and it is preferable to set it as 3-70 mol%.

  When the liquid crystal aligning ability is imparted to the coating film prepared using the liquid crystal aligning agent of the present invention by a photo-alignment method, at least one of the polymers (P) contained in the liquid crystal aligning agent has a photo-alignment structure. It is good also as a polymer to have.

（式（ｐ−１）中、Ｘ^３は、硫黄原子、酸素原子又は−ＮＨ−である。「＊」はそれぞれ結合手を示す。但し、２つの「＊」のうち少なくとも一方は芳香環に結合している。）
で表される部分構造が重合体の主鎖に導入された芳香環−ＣＯ含有構造等が挙げられる。 Here, the photo-alignment structure is a concept including both a photo-alignment group and a decomposition type photo-alignment part. Specifically, as the photoalignment structure, a group that exhibits photoalignment by photoisomerization, photodimerization, photolysis, or the like can be employed. For example, an azobenzene-containing group containing azobenzene or a derivative thereof as a basic skeleton. A group having a cinnamic acid structure containing cinnamic acid or a derivative thereof as a basic skeleton, a chalcone-containing group containing chalcone or a derivative thereof as a basic skeleton, a benzophenone-containing group containing benzophenone or a derivative thereof as a basic skeleton, coumarin or a derivative thereof A coumarin-containing group containing a derivative as a basic skeleton, a polyimide-containing structure containing polyimide or a derivative thereof as a basic skeleton, an unsaturated bond-containing structure in which a carbon-carbon unsaturated bond is introduced into the main chain of the polymer, p-1)

(In Formula (p-1), X ³ represents a sulfur atom, an oxygen atom or —NH—. “*” Represents a bond, respectively, provided that at least one of two “*” represents an aromatic ring. Combined.)
An aromatic ring-CO-containing structure in which a partial structure represented by the formula is introduced into the main chain of the polymer.

In the above formula (p-1), examples of the aromatic ring bonded to at least one of X ³ and a carbonyl group include a benzene ring, a naphthalene ring, and an anthracene ring. Among these, a benzene ring is preferable from the viewpoint of liquid crystal alignment and transparency. Of the two “*” in the formula (p-1), the structure on the side not bonded to the aromatic ring is not particularly limited. For example, a chain hydrocarbon structure, an aliphatic ring, an aromatic ring (aromatic hydrocarbon ring) And aromatic heterocycles), and alicyclic heterocycles. Among these, in terms of sensitivity to light, it is preferable that two “*” are both bonded to an aromatic ring, and more preferably bonded to an aromatic hydrocarbon ring. X ³ is preferably a sulfur atom in terms of sensitivity to light, and is preferably an oxygen atom in terms of availability and a wide range of usable monomer options.

When the liquid crystal aligning agent of the present invention is used for photo-alignment, at least a part of the polymer (P) is preferably a polymer having a photo-alignment structure in the main chain, and a polyimide-containing structure or an aromatic ring-CO. A polymer having a containing structure is more preferable.
When the polymer (P) has a polyimide-containing structure, the polymer preferably has a bicyclo [2.2.2] octene skeleton or a cyclobutane skeleton. Such a polymer is, for example, at least one of cyclobutanetetracarboxylic dianhydride and bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic dianhydride. It can be obtained by reacting a tetracarboxylic dianhydride containing diamine with a diamine compound containing a specific diamine.
When the polymer (P) has an aromatic ring-CO-containing structure, the polymer has a partial structure represented by "-benzene ring-COO-" or "-benzene ring-OCO-" as the main chain. It is preferable to have. Such a polymer can be obtained, for example, by polymerization containing, as a monomer, at least one of a tetracarboxylic dianhydride having the partial structure and a diamine having the partial structure. Specific examples of the monomer include compounds represented by the following formulas (p-1-1) to (p-1-6).

  When synthesizing a polymer having a photoalignment structure in the main chain, the proportion of the monomer having a photoalignment structure is 20 with respect to the total amount of monomers used for the synthesis of the polymer from the viewpoint of photoreactivity. It is preferable to set it as mol% or more, and it is more preferable to set it as 30-80 mol%.

[Synthesis of polyamic acid (P)]
The ratio of the tetracarboxylic dianhydride and diamine used in the synthesis reaction of the polyamic acid (P) is such that the acid anhydride group of the tetracarboxylic dianhydride is 0. A ratio of 2 to 2 equivalents is preferable, and a ratio of 0.3 to 1.2 equivalents is more preferable.

In synthesizing the polyamic acid (P), a terminal-modified polymer may be synthesized using an appropriate molecular weight regulator together with the tetracarboxylic dianhydride and diamine as described above. By using such a terminal-modified polymer, the coating property (printability) of the liquid crystal aligning agent can be further improved without impairing the effects of the present invention.
Examples of the molecular weight regulator include acid monoanhydrides such as maleic anhydride, phthalic anhydride and itaconic anhydride, monoamine compounds such as aniline, cyclohexylamine and n-butylamine, and monoisocyanate compounds such as phenyl isocyanate and naphthyl isocyanate. Can be mentioned. The use ratio of the molecular weight regulator is preferably 20 parts by weight or less, and more preferably 10 parts by weight or less with respect to 100 parts by weight of the total of the tetracarboxylic dianhydride and diamine used.

The polyamic acid synthesis reaction is preferably carried out in an organic solvent. Examples of the organic solvent used in the reaction include aprotic polar solvents, phenol solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons, hydrocarbons, and the like. Among these organic solvents, one or more selected from the group consisting of an aprotic polar solvent and a phenolic solvent (first group organic solvent), or one or more selected from the first group of organic solvents And a mixture of at least one selected from the group consisting of alcohols, ketones, esters, ethers, halogenated hydrocarbons and hydrocarbons (second-group organic solvent). In the latter case, the proportion of the second group organic solvent used is preferably 50% by weight or less, more preferably 40% by weight, based on the total amount of the first group organic solvent and the second group organic solvent. Or less, more preferably 30% by weight or less.
Particularly preferred are N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide, m-cresol, xylenol and halogen. It is preferable to use one or more selected from the group consisting of fluorinated phenols as a solvent, or to use a mixture of one or more of these and another organic solvent in the above range.
The amount of organic solvent used (a) is such that the total amount (b) of tetracarboxylic dianhydride and diamine is 0.1 to 50% by weight based on the total amount (a + b) of the reaction solution. Is preferred. The reaction temperature in the synthesis reaction of polyamic acid is preferably -20 ° C to 150 ° C, and more preferably 0 to 100 ° C. The reaction time is preferably 0.1 to 24 hours, more preferably 0.5 to 12 hours.

  As described above, a reaction solution obtained by dissolving the polyamic acid (P) is obtained. This reaction solution may be used for the preparation of the liquid crystal aligning agent as it is, may be used for the preparation of the liquid crystal aligning agent after isolating the polyamic acid (P) contained in the reaction solution, or the isolated polyamic acid. You may use for refinement | purification of a liquid crystal aligning agent, after refine | purifying (P). When the polyamic acid (P) is dehydrated and cyclized into a polyimide, the reaction solution may be subjected to the dehydration and cyclization reaction as it is, and the polyamic acid (P) contained in the reaction solution is isolated and then dehydrated and cyclized. You may use for reaction or you may use for dehydration ring closure after refine | purifying the isolated polyamic acid (P). Isolation and purification of the polyamic acid can be performed according to known methods.

[Polyamic acid ester (P)]
The polyamic acid ester (hereinafter also referred to as polyamic acid ester (P)) as the polymer (P) is, for example, [I] a polyamic acid (P) obtained by the above synthesis reaction, a hydroxyl group-containing compound, and an ester. [II] a method of reacting a tetracarboxylic acid diester and a diamine, [III] a method of reacting a tetracarboxylic acid diester dihalide and a diamine, and the like.

  Here, as an esterifying agent used by method [I], an acetal type compound, a halide, an epoxy-group containing compound etc. are mentioned, for example. Specific examples thereof include hydroxyl group-containing compounds such as alcohols such as methanol, ethanol and propanol; phenols such as phenol and cresol; and acetal compounds such as N, N-dimethylformamide diethyl acetal, N, N-diethylformamide diethyl acetal and the like; halides such as methyl bromide, ethyl bromide, stearyl bromide, methyl chloride, stearyl chloride, 1,1,1-trifluoro-2-iodoethane and the like; epoxy group-containing Examples of the compound include propylene oxide.

  The tetracarboxylic acid diester used in Method [II] can be obtained by ring-opening tetracarboxylic dianhydride using the above alcohols. The tetracarboxylic acid diester dihalide used in the method [III] can be obtained by reacting the tetracarboxylic acid diester obtained as described above with an appropriate chlorinating agent such as thionyl chloride. The diamine used in the methods [II] and [III] preferably contains the above-mentioned specific diamine, and other diamines may be used as necessary. The polyamic acid ester (P) may have only an amic acid ester structure, or may be a partially esterified product in which an amic acid structure and an amic acid ester structure coexist.

[Polyimide (P)]
The polyimide (hereinafter also referred to as polyimide (P)) as the polymer (P) can be obtained, for example, by dehydrating and ring-closing and imidizing the polyamic acid (P) synthesized as described above. .

  The polyimide (P) may be a completely imidized product obtained by dehydrating and ring-closing all of the amic acid structure of the polyamic acid (P) that is the precursor, and only a part of the amic acid structure is dehydrating and ring-closing. Alternatively, it may be a partially imidized product in which an amic acid structure and an imide ring structure coexist. As for the polyimide contained in the liquid crystal aligning agent of this invention, it is preferable that the imidation ratio is 30% or more, It is more preferable that it is 40 to 99%, It is still more preferable that it is 50 to 99%. This imidation ratio represents the ratio of the number of imide ring structures to the total of the number of polyimide amic acid structures and the number of imide ring structures in percentage. Here, a part of the imide ring may be an isoimide ring.

  The polyamic acid is preferably dehydrated and closed by heating the polyamic acid, or by dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydrating ring-closing catalyst to the solution, and heating the solution as necessary. . Of these, the latter method is preferred.

  In the method 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 as the dehydrating agent. It is preferable that the usage-amount of a dehydrating agent shall be 0.01-20 mol with respect to 1 mol of the amic acid structure of a polyamic acid. As the dehydration ring closure catalyst, for example, tertiary amines such as pyridine, collidine, lutidine, triethylamine and the like can be used. It is preferable that the usage-amount of a dehydration ring-closing catalyst shall be 0.01-10 mol with respect to 1 mol of dehydrating agents to be used. Examples of the organic solvent used in the dehydration ring-closing reaction include the organic solvents exemplified as those used for the synthesis of polyamic acid. 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 1.0 to 120 hours, more preferably 2.0 to 30 hours.

  In this way, a reaction solution containing polyimide (P) is obtained. This reaction solution may be used for the preparation of the liquid crystal aligning agent as it is, 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, and the liquid crystal after isolating the polyimide. You may use for preparation of an aligning agent, or you may use for preparation of a liquid crystal aligning agent, after purifying the isolated polyimide. These purification operations can be performed according to known methods. In addition, polyimide (P) can also be obtained by imidation of polyamic acid ester (P).

The polyamic acid (P), polyamic acid ester (P), and polyimide (P) obtained as described above have a solution viscosity of 10 to 800 mPa · s when this is a 10% by weight solution. Preferably, it has a solution viscosity of 15 to 500 mPa · s. In addition, the solution viscosity (mPa · s) of the above polymer is based on a polymer solution having a concentration of 10% by weight prepared using a good solvent for the polymer (eg, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.). The value measured at 25 ° C. using an E-type rotational viscometer.
The polystyrene equivalent weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) of the polyamic acid, polyamic acid ester and polyimide is preferably 1,000 to 500,000, more preferably 2,000. ~ 300,000. Moreover, the molecular weight distribution (Mw / Mn) represented by the ratio between Mw and the polystyrene-equivalent number average molecular weight (Mn) measured by GPC is preferably 15 or less, more preferably 10 or less. By being in such a molecular weight range, it is possible to ensure good orientation and stability of the liquid crystal display element.

<Other ingredients>
Although the liquid crystal aligning agent of this invention contains the said polymer (P), you may contain the other component as needed. Other components that may be added to the liquid crystal aligning agent include, for example, other polymers other than the polymer (P), compounds having at least one epoxy group in the molecule (hereinafter referred to as “epoxy group-containing compound”). And a functional silane compound.

[Other polymers]
The above other polymers can be used for improving solution properties and electrical properties. Such other polymer is a polymer having no partial structure represented by the above formula (1), and the main skeleton thereof is not particularly limited. Specifically, for example, polyamic acid, polyimide, polyamic acid ester, polyorganosiloxane, polyester, polyamide, cellulose derivative, polyacetal, polystyrene derivative, poly (styrene-phenylmaleimide) derivative, poly (meth) acrylate and the like as the main skeleton Can be mentioned. Among these, at least one polymer selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, and polyorganosiloxane is preferable.
When adding another polymer to a liquid crystal aligning agent, it is preferable that the mixture ratio shall be 50 weight part or less with respect to a total of 100 weight part of the polymer contained in a liquid crystal aligning agent, The amount is more preferably 40 parts by weight, and still more preferably 0.1 to 30 parts by weight.

[Epoxy group-containing compound]
The epoxy group-containing compound can be used to improve the adhesion and electrical properties with the substrate surface in the liquid crystal alignment film. Examples of such epoxy group-containing compounds include 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, glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, N, N, N ′, N′-tetraglycidyl-m-xylylene diene Amine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ′, N′-tetraglycidyl-4,4′-diamy Diphenylmethane, N, N-diglycidyl - benzylamine, N, N-diglycidyl - aminomethyl cyclohexane, N, N-diglycidyl - may be mentioned as being preferred and cyclohexylamine. In addition, as an example of the epoxy group-containing compound, an epoxy group-containing polyorganosiloxane described in International Publication No. 2009/096598 can be used.
When adding these epoxy compounds to a liquid crystal aligning agent, it is preferable that the mixture ratio shall be 40 weight part or less with respect to a total of 100 weight part of the polymer contained in a liquid crystal aligning agent, 0.1-30 More preferred are parts by weight.

[Functional silane compounds]
The functional silane compound can be used for the purpose of improving the printability of the liquid crystal aligning agent. Examples of such functional silane compounds 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- Aminopropyltrimethoxysilane, N-triethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-trimethoxysilyl -3,6- Methyl azananoate, N-benzyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, glycidoxymethyltrimethoxysilane, 2-glycidoxyethyltrimethoxysilane, 3-glycid And xylpropyltrimethoxysilane.
When these functional silane compounds are added to the liquid crystal aligning agent, the blending ratio is preferably 2 parts by weight or less with respect to a total of 100 parts by weight of the polymer contained in the liquid crystal aligning agent. It is more preferable to set it to -0.2 weight part.

  In addition, as another component, the additive normally used for preparation of a liquid crystal aligning agent can be used. Examples of additives other than the above include compounds having at least one oxetanyl group in the molecule, antioxidants, and surfactants.

<Solvent>
The liquid crystal aligning agent of the present invention is prepared as a liquid composition in which the polymer (P) and other components used as necessary are preferably dispersed or dissolved in an appropriate solvent.

  Examples of the organic solvent to be used include 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, diethylene glycol dimethyl ether, diethylene glycol Recall diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, diisopentyl ether, ethylene carbonate, propylene carbonate, etc. be able to. These can be used alone or in admixture of two or more.

  The solid content concentration in the liquid crystal aligning agent of the present invention (the ratio of the total weight of components other than the solvent of the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) is appropriately selected in consideration of viscosity, volatility, and the like. The range is preferably 1 to 10% by weight. That is, the liquid crystal aligning agent of this invention is apply | coated to a substrate surface so that it may mention later, Preferably the coating film which becomes a liquid crystal aligning film or a coating film used as a liquid crystal aligning film is formed by heating. At this time, when the solid content concentration is less than 1% by weight, the film thickness of the coating film becomes too small, and it becomes difficult to obtain a good liquid crystal alignment film. On the other hand, when the solid content concentration exceeds 10% by weight, it is difficult to obtain a good liquid crystal alignment film because the film thickness is excessive, and the viscosity of the liquid crystal aligning agent increases and the applicability decreases. There is a tendency.

  The particularly preferable range of the solid content concentration varies depending on the method used when the liquid crystal aligning agent is applied to the substrate. For example, when the spinner method is used, the solid content concentration (the ratio of the total weight of all components other than the solvent in the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) is in the range of 1.5 to 4.5% by weight. It is particularly preferred. 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 inkjet 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 the time of preparing the liquid crystal aligning agent of this invention becomes like this. Preferably it is 10-50 degreeC, More preferably, it is 20-30 degreeC.

[Liquid crystal alignment film and liquid crystal display element]
By using the liquid crystal aligning agent of the present invention described above, a liquid crystal aligning film can be produced. The liquid crystal display element of this invention comprises the liquid crystal aligning film formed using the said liquid crystal aligning agent. The operation mode of the liquid crystal display element of the present invention is not particularly limited. For example, TN type, STN type, VA type (including VA-MVA type, VA-PVA type, etc.), IPS type, FFS type, OCB type, etc. It can be applied to the operation mode.

  The liquid crystal display element of this invention can be manufactured according to the process including the following processes (1-1)-(1-3), for example. In the step (1-1), a substrate to be used is different depending on a desired operation mode. Step (1-2) and step (1-3) are common to each operation mode.

[Step (1-1): Formation of coating film]
First, the liquid crystal aligning agent of this invention is apply | coated on a board | substrate, Then, a coating film is formed on a board | substrate by heating an application surface.
(1-1A) When manufacturing a TN-type, STN-type, or VA-type liquid crystal display element, for example, first, a pair of two substrates on which patterned transparent conductive films are provided, and each transparent conductive film is formed. On the surface, the liquid crystal aligning agent of the present invention is preferably applied by an offset printing method, a spin coating method, a roll coater method or an ink jet printing method, respectively. 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, poly (cycloaliphatic olefin) can be used. As a transparent conductive film provided on one surface of the substrate, 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 ), etc. Can be used. In order to obtain a patterned transparent conductive film, for example, after forming a transparent conductive film without a pattern, a method of forming a pattern by photo-etching; a method of using a mask having a desired pattern when forming a transparent conductive film; And so on. 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 or a functional titanium compound is formed on the surface of the substrate surface on which the coating film is formed. It is also possible to perform a pretreatment to apply the above in advance.

  After applying the liquid crystal aligning agent, preheating (pre-baking) is preferably performed for the purpose of preventing dripping of the applied liquid crystal aligning agent. The pre-baking temperature is preferably 30 to 200 ° C, more preferably 40 to 150 ° C, and particularly preferably 40 to 100 ° C. The pre-bake time is preferably 0.25 to 10 minutes, and more preferably 0.5 to 5 minutes. Then, a baking (post-baking) process is implemented for the purpose of removing a solvent completely and heat imidating the amic acid structure which exists in a polymer as needed. The firing temperature (post-bake temperature) at this time 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 thickness of the film thus formed is preferably 0.001 to 1 μm, more preferably 0.005 to 0.5 μm.

  (1-1B) When manufacturing an IPS type or FFS type liquid crystal display element, an electrode forming surface of a substrate provided with an electrode made of a transparent conductive film or a metal film patterned in a comb shape, and an electrode are provided. The liquid crystal aligning agent of this invention is each apply | coated to one surface of the counter substrate which is not formed, Then, a coating film is formed by heating each application surface. Regarding the material used for the substrate and the transparent conductive film, the coating method, the heating conditions after coating, the patterning method for the transparent conductive film or the metal film, the pretreatment of the substrate, and the preferred film thickness of the coating film to be formed The same as (1-1A). As the metal film, for example, a film made of a metal such as chromium can be used.

  In both cases (1-1A) and (1-1B), after applying a liquid crystal aligning agent on the substrate, the organic solvent is removed to form a liquid crystal alignment film or a liquid crystal alignment film. The At this time, by further heating after the formation of the coating film, the dehydration ring-closing reaction of the polyamic acid, polyamic acid ester and polyimide blended in the liquid crystal aligning agent of the present invention may be advanced to obtain a more imidized coating film.

[Step (1-2): Orientation ability imparting treatment]
When manufacturing a TN type, STN type, IPS type, or FFS type liquid crystal display element, the process which provides liquid crystal aligning ability to the coating film formed at the said process (1-1) is implemented. Thereby, the orientation ability of a liquid crystal molecule is provided to a coating film, and it becomes a liquid crystal aligning film. Examples of the alignment ability imparting treatment include a rubbing treatment in which a coating film is rubbed in a fixed direction with a roll wound with a cloth made of fibers such as nylon, rayon, and cotton, and photo-alignment in which the coating film is irradiated with polarized or non-polarized radiation. Processing. On the other hand, when manufacturing a VA type liquid crystal display element, the coating film formed in the above step (1-1) can be used as it is as a liquid crystal alignment film. May be.

When the liquid crystal alignment ability is imparted to the coating film by the photo-alignment treatment, for example, ultraviolet rays and visible rays including light having a wavelength of 150 to 800 nm can be used as the radiation applied to the coating film. When the radiation is polarized light, it may be linearly polarized light or partially polarized light. When the radiation used is linearly polarized light or partially polarized light, irradiation may be performed from a direction perpendicular to the substrate surface, an oblique direction, or a combination thereof. When irradiating non-polarized radiation, the direction of irradiation is an oblique direction.
As a light source to be used, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, an excimer laser, or the like can be used. Ultraviolet rays in a preferable wavelength region can be obtained by means of using a light source in combination with, for example, a filter or a diffraction grating. The radiation dose is preferably 100 to 50,000 J / m ² , more preferably 300 to 20,000 J / m ² . Moreover, you may perform light irradiation with respect to a coating film, heating a coating film, in order to improve the reactivity. The temperature at the time of heating is 30-250 degreeC normally, Preferably it is 40-200 degreeC, More preferably, it is 50-150 degreeC.

  In addition, the liquid crystal alignment film after the rubbing treatment is further subjected to a process for changing the pretilt angle of a part of the liquid crystal alignment film by irradiating a part of the liquid crystal alignment film with ultraviolet rays or a surface of the liquid crystal alignment film. A resist film is formed on the part, and a rubbing process is performed in a direction different from the previous rubbing process, followed by a process of removing the resist film, so that the liquid crystal alignment film has different liquid crystal alignment capabilities for each region. . In this case, it is possible to improve the visibility characteristics of the obtained liquid crystal display element. A liquid crystal alignment film suitable for a VA liquid crystal display element can also be suitably used for a PSA (Polymer sustained alignment) type liquid crystal display element.

[Step (1-3): Construction of liquid crystal cell]
Two substrates on which the liquid crystal alignment film is formed as described above are prepared, and a liquid crystal cell is manufactured by disposing a liquid crystal between the two substrates disposed to face each other. 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 opposite to 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 together using a sealant, and the substrate surface and the sealant are bonded. A liquid crystal cell is manufactured by injecting and filling the liquid crystal into the cell gap partitioned by the step of sealing the injection hole. The second method is a method called an ODF (One Drop Fill) method. For example, an ultraviolet light curable sealant 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 at predetermined locations on the liquid crystal alignment film surface. After that, the other substrate is bonded so that the liquid crystal alignment films face each other and the liquid crystal is spread over the entire surface of the substrate, and then the entire surface of the substrate is irradiated with ultraviolet light to cure the sealant, thereby manufacturing a liquid crystal cell. . Regardless of which method is used, the liquid crystal cell produced as described above is further heated to a temperature at which the liquid crystal used takes an isotropic phase and then gradually cooled to room temperature. It is desirable to remove.

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, phenylcyclohexane liquid crystal, ester liquid crystal, terphenyl liquid crystal, biphenyl. Cyclohexane liquid crystals, pyrimidine liquid crystals, dioxane liquid crystals, bicyclooctane liquid crystals, cubane liquid crystals, and the like can be used. Further, cholesteric liquid crystals such as cholestyl chloride, cholesteryl nonate, and cholesteryl carbonate; chiral agents such as those sold under the trade names “C-15” and “CB-15” (manufactured by Merck & Co., Inc.). A ferroelectric liquid crystal such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate may be added and used.

  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. As a polarizing plate to be bonded to the outer surface of the liquid crystal cell, a polarizing film or an H film itself in which a polarizing film called an “H film” in which iodine is absorbed while stretching and aligning polyvinyl alcohol is sandwiched between cellulose acetate protective films The polarizing plate which consists of can be mentioned.

  The liquid crystal display element of the present invention can be effectively applied to various devices, such as watches, portable games, word processors, notebook computers, car navigation systems, camcorders, PDAs, digital cameras, mobile phones, smartphones, The present invention can be used for various display devices such as various monitors, liquid crystal televisions, and information displays.

  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 examples, the solution viscosity of the polymer solution was measured by the following method. Hereinafter, the compound represented by Formula X may be simply referred to as “Compound X”.
[Solution viscosity of polymer solution]
The solution viscosity [mPa · s] of the polymer solution was measured at 25 ° C. using an E-type rotational viscometer for a solution prepared to a polymer concentration of 10% by weight using a predetermined solvent.

<Synthesis of compounds>
[Example 1-1: Synthesis of compound (DA-1)]
According to the following scheme 1, the compound represented by the following formula (DA-1) was synthesized.

2.5 g of 2-chloro-5-nitropyridine was suspended in 25 ml of toluene, and 1.88 g of triethylamine was added thereto. A solution prepared by dissolving 0.5 g of piperazine in 2 ml of chloroform was slowly dropped into the container. The mixture was stirred at room temperature for 30 minutes and then stirred at 80 ° C. for 12 hours. At this time, a yellow solid precipitated as the reaction proceeded. After cooling, the solid was filtered, washed well with water, and then toluene was removed with ethyl acetate. The obtained solid was dried to obtain 1.94 g of Compound (DA-1-1) with a purity of 99%.
Next, the three-necked flask in which 0.3 g of Pd / C was separated was purged with nitrogen, and 40 ml of ethanol degassed with oxygen was added thereto and stirred. 1.94 g of compound (DA-1-1) was put into the container, cooled to 0 ° C. and stirred for 5 minutes. After stirring, 5 ml of hydrazine monohydrate was slowly added dropwise to the reaction solution.
The reaction was completed by stirring at 0 ° C. for 3 hours and at room temperature for 6 hours. 100 ml of ethyl acetate and 80 ml of THF were added, and then 60 ml of pure water was added, followed by liquid separation. After liquid separation again with pure water, this was concentrated to obtain 1.5 g of compound (DA-1) as a yellow to white solid having a purity of 99%.

[Example 1-2: Synthesis of compound (DA-2)]
According to the following scheme 2, the compound represented by the following formula (DA-2) was synthesized.

2.68 g of 2-chloro-5-nitropyridine was suspended in 25 ml of toluene, and 1.99 g of triethylamine was added thereto. A solution prepared by dissolving 0.51 g of N, N′-dimethylethylenediamine in 2 ml of chloroform was slowly dropped into the container. The mixture was stirred at room temperature for 30 minutes and then stirred at 80 ° C. for 12 hours. At this time, a yellow solid precipitated as the reaction proceeded. After cooling, the solid was filtered, washed well with water, and toluene was removed with ethyl acetate. This solid was dried to obtain 1.69 g of Compound (DA-2-1) with a purity of 96%.
Next, the three-necked flask in which 0.3 g of Pd / C was separated was purged with nitrogen, and 40 ml of ethanol degassed with oxygen was added thereto and stirred. Compound (DA-2-1) 1.69g was put into the container, it cooled at 0 degreeC, and stirred for 5 minutes. After stirring, 5 ml of hydrazine monohydrate was slowly added dropwise to the reaction solution.
The reaction was completed by stirring at 0 ° C. for 3 hours and at room temperature for 6 hours. 100 ml of ethyl acetate and 80 ml of THF were added, and then 60 ml of pure water was added, followed by liquid separation. After liquid separation again with pure water, this was concentrated to obtain 1.18 g of compound (DA-2) as 97% purity and 1.18 g of a yellow solid.

[Example 1-3: Synthesis of compound (DA-3)]
According to the following scheme 3, a compound represented by the following formula (DA-3) was synthesized.

2.82 g of 2-chloro-5-nitropyrimidine was suspended in 25 ml of toluene, and 1.99 g of triethylamine was added thereto. A solution prepared by dissolving 0.5 g of piperazine in 2 ml of chloroform was slowly dropped into the container. The mixture was stirred at room temperature for 30 minutes and then stirred at 80 ° C. for 12 hours. At this time, a yellow solid precipitated as the reaction proceeded. After cooling, the solid was filtered, washed well with water, and toluene was removed with ethyl acetate. This solid was dried to obtain 1.51 g of Compound (DA-3-1) with a purity of 98%.
Next, the three-necked flask in which 0.3 g of Pd / C was separated was replaced with nitrogen, and 40 ml of ethanol degassed with oxygen was added thereto and stirred. The compound (DA-3-1) 1.51 g was put into the container, cooled to 0 ° C. and stirred for 5 minutes. After stirring, 5 ml of hydrazine monohydrate was slowly added dropwise to the reaction solution.
The reaction was completed by stirring at 0 ° C. for 3 hours and at room temperature for 6 hours. 100 ml of ethyl acetate and 80 ml of THF were added, and then 60 ml of pure water was added, followed by liquid separation. After liquid separation again with pure water, this was concentrated to obtain 1.02 g of compound (DA-3) as a yellow solid having a purity of 98%.

[Example 1-4: Synthesis of compound (DA-4)]
According to the following scheme 4, a compound represented by the following formula (DA-4) was synthesized.

2.5 g of 4-chloro-2-nitropyridine was suspended in 25 ml of toluene, and 1.88 g of triethylamine was added thereto. A solution prepared by dissolving 0.5 g of piperazine in 2 ml of chloroform was slowly dropped into the container. The mixture was stirred at room temperature for 30 minutes and then stirred at 80 ° C. for 12 hours. At this time, a yellow solid precipitated as the reaction proceeded. After cooling, the solid was filtered, washed well with water, and toluene was removed with ethyl acetate. This solid was dried to obtain 1.78 g of Compound (DA-4-1) with a purity of 96%.
Next, the three-necked flask in which 0.3 g of Pd / C was separated was replaced with nitrogen, and 40 ml of ethanol degassed with oxygen was added thereto and stirred. 1.78 g of compound (DA-4-1) was put into the container, cooled to 0 ° C. and stirred for 5 minutes. After stirring, 5 ml of hydrazine monohydrate was slowly added dropwise to the reaction solution.
The reaction was completed by stirring at 0 ° C. for 3 hours and at room temperature for 6 hours. 100 ml of ethyl acetate and 80 ml of THF were added, and then 60 ml of pure water was added, followed by liquid separation. After liquid separation again with pure water, this was concentrated to obtain 1.44 g of compound (DA-4) as a yellow to white solid with a purity of 98%.

[Example 1-5: Synthesis of compound (DC-1)]
According to the following scheme 5, the compound represented by the following formula (DC-1) was synthesized.

2.7 g of compound (DA-1) was suspended in 25 ml of pure water, and 5.6 g of potassium hydroxide and 13.9 g of bromoacetic acid were added thereto, followed by stirring at 90 ° C. for 12 hours. At this time, it turned brown as the reaction progressed. After cooling, the reaction solution was poured into 100 mL of cold concentrated hydrochloric acid, and the reprecipitated solid was filtered and washed well with water. This solid was dried to obtain 3.6 g of Compound (DC-1-1) with a purity of 98%.
Subsequently, the compound (DC-1-1) 3.6g and acetic anhydride 20mL were put into the container, and it stirred at 60 degreeC for 6 hours. The solid precipitated after cooling was filtered to obtain 2.2 g of Compound (DC-1) as a yellow to white solid having a purity of 98%.

<Synthesis of polymer>
[Example 2-1: Synthesis of polyamic acid (P1)]
2,3,5-tricarboxycyclopentylacetic acid dianhydride 50 mol part and tetramellitic dianhydride 50 mol part as tetracarboxylic dianhydride, p-phenylenediamine 50 mol part as diamine, and compound (DA- 1) 50 mol part was dissolved in N-methyl-2-pyrrolidone (NMP) and reacted at 60 ° C. for 6 hours to obtain a solution containing 20% by weight of polyamic acid. 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 80 mPa · s.

[Examples 2-2 to 2-28 and Synthesis examples 2-29 to 2-32]
Polyamic acids (P2) to (P32) were synthesized in the same manner as in Example 2-1, except that the types and amounts of tetracarboxylic dianhydride and diamine used were changed as shown in Table 1 below.

In Table 1, the numbers in parentheses of tetracarboxylic dianhydride and diamine represent the usage ratio [mole part] with respect to a total of 100 parts by mole of tetracarboxylic dianhydride used for the synthesis of the polymer. Abbreviations in Table 1 have the following meanings, respectively.
<Tetracarboxylic dianhydride>
t-1: 2,3,5-tricarboxycyclopentyl acetic acid dianhydride t-2: pyromellitic dianhydride t-3: 1,2,3,4-cyclobutanetetracarboxylic dianhydride t-4: p-Phenylenebis (trimellitic acid monoester anhydride)
t-5: 1R, 2S, 4S, 5R-1, 2, 4, 5-cyclohexanetetracarboxylic dianhydride t-6: ethylenediaminetetraacetic acid dianhydride <diamine>
d-1: p-phenylenediamine d-2: 4,4′-diaminodiphenyl ether d-3: 3,5-diaminobenzoic acid d-4: 4-aminophenyl-4′-aminobenzoate d-5: Compound represented by (d-5) d-6: Compound represented by the following formula (d-6) d-7: Compound represented by the following formula (d-7) DA-5: Formula (DA -5) Compound DA-6: Compound represented by the following formula (DA-6)

[Example 1A]
(1) Preparation of liquid crystal aligning agent As a polymer, NMP and butyl cellosolve (BC) are added as solvents to the polyamic acid (P1) obtained in Example 2-1 above, and the solvent composition is NMP: BC = 50: 50 (weight). Ratio), and a solution having a solid content concentration of 6.0% by weight. A liquid crystal aligning agent (S1) was prepared by filtering this solution using a filter having a pore diameter of 1 μm.

(2) Manufacture of liquid crystal display element for rubbing alignment The liquid crystal aligning agent (S1) prepared above was apply | coated with the spinner on the glass substrate of thickness 1mm which has the chromium electrode provided in the comb-tooth shape on the single side | surface. Subsequently, after pre-baking for 1 minute on an 80 degreeC hotplate, it post-baked for 10 minutes on a 230 degreeC hotplate, and formed the coating film with a film thickness of about 800 mm. Using a rubbing machine having a roll around which a nylon cloth is wound on the formed coating surface, the roll rotation speed is 1,000 rpm, the stage moving speed is 25 mm / second, and the length of pushing the hair foot is 0.4 mm. A rubbing treatment was performed to give liquid crystal alignment ability. Further, this substrate was ultrasonically cleaned in ultrapure water for 1 minute and dried in a 100 ° C. clean oven for 10 minutes to produce a substrate having a liquid crystal alignment film on the surface having comb-like chrome electrodes. The substrate having this liquid crystal alignment film was referred to as “substrate A”.

  Separately, a coating film of the liquid crystal aligning agent (S1) is formed on one surface of a glass substrate having a thickness of 1 mm that does not have an electrode in the same manner as described above, and is rubbed, washed, and dried. A substrate having a liquid crystal alignment film thereon was produced. The substrate having this liquid crystal alignment film was referred to as “substrate B”.

  Subsequently, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm is applied to the outer edge of the surface of the substrate A having the liquid crystal alignment film, and then the rubbing direction in each liquid crystal alignment film is antiparallel. The two substrates A and B were placed opposite to each other, and the outer edge portions were brought into contact with each other and pressed to cure the adhesive. Next, a nematic liquid crystal (MLC-2042, manufactured by Merck & Co., Inc.) is filled between a pair of substrates from the liquid crystal injection port, and then the liquid crystal injection port is sealed with an acrylic photo-curing adhesive to produce an IPS type liquid crystal cell. did.

(3) Evaluation of reliability Reliability was evaluated using the liquid crystal cell manufactured by said (2). Evaluation was performed as follows. First, a voltage of 5 V was applied to the liquid crystal cell with an application time of 60 microseconds and a span of 167 milliseconds, and then the voltage holding ratio (VHR1) after 167 milliseconds from the release of application was measured. Next, the liquid crystal cell was allowed to stand in an 80 ° C. oven under LED lamp irradiation for 200 hours, and then allowed to stand at room temperature and naturally cooled to room temperature. After cooling, a voltage of 5 V was applied to the liquid crystal cell with an application time of 60 microseconds and a span of 167 milliseconds, and then the voltage holding ratio (VHR2) 167 milliseconds after the application release was measured. The measuring device used was “VHR-1” manufactured by Toyo Corporation. The change rate (ΔVHR) of VHR at this time was calculated by the following mathematical formula (2), and the reliability was evaluated by ΔVHR. Evaluation is when ΔVHR is less than 1%, reliability is “good” (◎), when 1% or more and less than 2%, reliability is “good” (◯), when 2% or more Reliability was determined as “bad (×)”. As a result, in Example 1A, the reliability was “good”.
ΔVHR [%] = (VHR1−VHR2) / (VHR1) × 100 (2)

(4) Evaluation of liquid crystal orientation With respect to the liquid crystal cell produced in (2) above, the presence or absence of abnormal domains when the voltage is turned on / off (applied / released) is observed with a polarizing microscope. When the orientation was “good” and there was even one abnormal domain, the liquid crystal orientation was judged as “poor”. As a result, the liquid crystal alignment of the liquid crystal cell of this example was “good”.

(5) Afterimage characteristics (burn-in characteristics)
Except for using as a pair a glass substrate having two metal electrodes (electrode a and electrode b) made of chromium patterned in a comb shape on one side and a counter glass substrate on which no electrode is provided as a substrate. An IPS type liquid crystal cell was produced in the same manner as (2) above. Subsequently, a polarizing plate was bonded to both outer surfaces of the substrate of the liquid crystal cell to produce a liquid crystal display element. This IPS type liquid crystal display element was placed in an environment of 25 ° C. and 1 atm. A voltage was applied to the electrode a for 2 hours without applying a voltage to the electrode b, for an AC voltage of 3.5 V and a DC voltage of 5 V. Immediately thereafter, an AC voltage of 4 V was applied to both electrode a and electrode b. The time from when the voltage of 4 V AC was started to be applied to both electrodes until the difference in light transmittance between the electrodes a and b could not be visually confirmed was measured. When this time is less than 100 seconds, the afterimage characteristics are “good”, afterimage characteristics when the time is more than 100 seconds and less than 150 seconds are “good”, and afterimage characteristics when it exceeds 150 seconds are “bad”. As evaluated. As a result, in the liquid crystal cell of Example 1A, the afterimage characteristics were “good”.

[Examples 2A to 11A, 28A and Comparative Examples 1 and 2]
The liquid crystal aligning agents (S2) to (S11) and (S28) to (S30) were respectively used at the same solvent ratio and solid content concentration as in Example 1A except that the type of polymer used was changed as shown in Table 2 below. Prepared. Moreover, while producing a liquid crystal cell similarly to Example 1A using each liquid crystal aligning agent, various evaluation was performed using the obtained liquid crystal cell. The results are shown in Table 2 below.

[Example 12A]
(1) Preparation of liquid crystal aligning agent A liquid crystal aligning agent (S12) was prepared at the same solvent ratio and solid content concentration as in Example 1A, except that the type of polymer used was changed to polyamic acid (P12).
(2) Manufacture of liquid crystal display element for photo-alignment film The liquid crystal aligning agent (S12) prepared above is formed on a 1 mm-thick glass substrate having a chrome electrode provided in a comb shape on one side, and the film thickness is 0. The film was applied with a spinner so as to have a thickness of 1 μm, pre-baked on an 80 ° C. hot plate for 1 minute, and then post-baked on a hot plate at 230 ° C. for 10 minutes to form a coating film. The substrate having this coating film was designated “substrate A”.
Separately, a coating film of the liquid crystal aligning agent (S12) was formed on one surface of a 1 mm thick glass substrate having no electrode in the same manner as described above. The substrate having this coating film was designated as “Substrate B”.
Next, the coating film surfaces of the substrate A and the substrate B were irradiated with polarized ultraviolet rays of 10,000 J / m ² including a 254 nm emission line from the normal direction of the substrate using an Hg—Xe lamp to form a liquid crystal alignment film. .
Next, with respect to the pair of substrates subjected to the light irradiation treatment, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm was applied by screen printing leaving a liquid crystal injection port at the edge of the surface on which the liquid crystal alignment film was formed. Thereafter, the substrates were stacked and pressure-bonded so that the directions of projection of the polarization axes on the substrate surface during light irradiation were antiparallel, and the adhesive was thermally cured at 150 ° C. for 1 hour. Next, a nematic liquid crystal (MLC-7028, manufactured by Merck & Co., Inc.) was filled between the pair of substrates through the liquid crystal injection port, and then the liquid crystal injection port was sealed with an epoxy adhesive. Furthermore, in order to remove the flow alignment at the time of liquid crystal injection, this was heated at 150 ° C. and then gradually cooled to room temperature. Next, a polarizing plate was bonded to both outer surfaces of the substrate to produce a liquid crystal display element.

(3) Evaluation of reliability The reliability was evaluated in the same manner as in Example 1A except that the liquid crystal display device manufactured in (2) was used. In this example, ΔVHR = 1.6%. Yes, the result was “good” reliability.
(4) Evaluation of liquid crystal alignment Reliability was evaluated in the same manner as in Example 1A except that the liquid crystal display device manufactured in (2) was used. In this example, the liquid crystal alignment was “good”. It was the result.
(5) Afterimage characteristics (burn-in characteristics)
The afterimage characteristics were evaluated in the same manner as in Example 1A except that the liquid crystal aligning agent (S12) was used. In this example, the afterimage characteristics were “good”.

[Examples 13A to 27A and Comparative Examples 3 and 4]
The liquid crystal aligning agents (S13) to (S27), (S31), and (S32) were respectively used at the same solvent ratio and solid content concentration as in Example 1A except that the type of polymer used was changed as shown in Table 2 below. Prepared. In addition, a liquid crystal cell was produced in the same manner as Example 12A using each liquid crystal aligning agent, and various evaluations were performed using the obtained liquid crystal cell. The results are shown in Table 2 below.

As shown in Table 2, in all of Examples 1A to 28A, even after exposure to a light stress and heat stress environment for a long time (200 hours), the decrease in the voltage holding ratio is small and the reliability is good. there were. On the other hand, in Comparative Examples 1 to 4, the voltage holding ratio was greatly lowered by the application of light stress and thermal stress, and the reliability was evaluated as “bad”.
Regarding liquid crystal alignment, no alignment failure was observed in all of Examples 1A to 28A, and regarding the afterimage characteristics, any sample was evaluated as “good” or “good”.
As described above, it was confirmed that the liquid crystal alignment film having the structure used in the examples had highly reliable characteristics without disturbing the liquid crystal alignment.

Claims (6)

Liquid crystal alignment containing a polymer (P) obtained by polymerization comprising at least one compound selected from the group consisting of polyamic acid, polyamic acid ester and polyimide, and containing a compound represented by the following formula (3) in the monomer composition Agent.

(In formula (3), X ¹ is a divalent aromatic heterocyclic group containing a nitrogen atom in the ring portion. Z ¹ is a primary amino group or the following formula (z-1)

(In the formula (z-1), "*" indicates a bond to ^{X 1.)}
It is group represented by these. R ¹ is alkanediyl group having a carbon number of 1-6, ^{R 2} is either an alkyl group having a carbon number of 1-6, or two ^{R 2} are bonded to each other two nitrogen atoms and R to form a divalent alicyclic heterocyclic group unsubstituted ring members 5 to 7 together with ^1. Two X ¹ may be the same or different, and two R ² may be the same or different. p is 1 . ) R ² in the above formula (3) is an alkyl group having 1 to 3 carbon atoms, or two R ² are bonded to each other to form a 1,4-piperazinediyl group together with two nitrogen atoms and R ^1. that form a liquid crystal alignment agent according to claim 1.   The manufacturing method of the liquid crystal aligning film containing the process of forming a coating film using the liquid crystal aligning agent of Claim 1 or 2, and the process of light-irradiating the said coating film and providing liquid crystal aligning ability.   The manufacturing method of the liquid crystal aligning film containing the process of forming a coating film using the liquid crystal aligning agent of Claim 1 or 2, and the process of providing the liquid crystal aligning capability by rubbing the said coating film.   The liquid crystal aligning film formed with the liquid crystal aligning agent of Claim 1 or 2.   A liquid crystal display device comprising the liquid crystal alignment film according to claim 5.