JP6658845B2 - Liquid crystal alignment agent, liquid crystal alignment film and liquid crystal display device - Google Patents

Description

The present invention is a liquid crystal alignment agent, a liquid crystal alignment film and a liquid crystal display device.

  2. Description of the Related Art Conventionally, a liquid crystal alignment film of a display element, a surface protective film for a display element or a lighting device, an interlayer insulating film, and the like are produced by applying a polymer composition on a substrate. For example, as a liquid crystal display element, various driving methods having different electrode structures and physical properties of liquid crystal molecules to be used have been developed, and a TN type, an STN type, a vertical alignment type (VA type), and an in-plane switching type have been developed. Various types of liquid crystal display devices such as a liquid crystal display device (IPS type), an FFS type, and an optical compensation vent type (OCB type) are known. These liquid crystal display devices have a liquid crystal alignment film for aligning liquid crystal molecules. As a material for the liquid crystal alignment film, polyamic acid or polyimide is generally used because of its excellent properties such as heat resistance, mechanical strength, and affinity for liquid crystal.

  In a polymer composition such as a liquid crystal alignment agent, a polymer component is dissolved in a solvent, and the liquid crystal alignment agent is applied to a substrate and heated to form a liquid crystal alignment film. Here, as a solvent of the liquid crystal aligning agent, an aprotic polar solvent such as N-methyl-2-pyrrolidone or γ-butyrolactone is generally used for the purpose of uniformly dissolving the polymer. In addition, as a solvent for the liquid crystal aligning agent, usually together with a good solvent such as polyamic acid or the like, in order to improve the coating property (printability) of the liquid crystal aligning agent when applying the liquid crystal aligning agent to the substrate, for example, butyl cellosolve or the like. A poor solvent having a relatively low surface tension is used in combination (for example, see Patent Literature 1 and Patent Literature 2).

  In recent years, liquid crystal display elements have been used not only for display terminals such as personal computers as in the past, but also for various purposes such as liquid crystal televisions, car navigation systems, mobile phones, smartphones, and information displays. With such versatility, liquid crystal display devices are required to have higher display quality and higher product yields. Improvement of a liquid crystal alignment film, which is one of the constituent members, and a liquid crystal alignment agent, which is a material for forming the liquid crystal alignment film, are being promoted. For example, a liquid crystal aligning agent is required to have good coatability (printability) when applied on a substrate from the viewpoints of display quality and yield, and various materials for improving printability are required. It has been proposed (for example, see Patent Document 3 and Patent Document 4).

JP 2010-97188 A JP 2010-156934 A JP 2011-257527 A JP 2011-257736 A

  Demands for higher performance and higher yield of liquid crystal display elements have been further increased, and further improvement in printability of liquid crystal alignment agents has been required.

The present invention has been made in view of the above problems, printability good liquid crystal alignment material, and a main object thereof is to provide a liquid crystal alignment film and a liquid crystal display device manufactured using the liquid crystal aligning agent .

  The present inventors have conducted intensive studies to achieve the above-described problems of the related art, and as a result, in a composition containing polyimide or a precursor thereof as a polymer component, a specific solvent is used as at least a part of the solvent component. As a result, they have found that the above-mentioned problems can be solved, and have completed the present invention. Specifically, the present invention provides the following composition, liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display device.

  According to a first aspect of the present invention, there is provided a composition comprising at least one polymer (A) selected from the group consisting of polyamic acid, polyimide and polyamic acid ester, and a solvent, wherein the solvent comprises: Provided is a composition comprising at least one selected from the group consisting of a compound represented by the formula (b1) and a compound represented by the following formula (b2). In a second aspect, the present invention provides a liquid crystal aligning agent containing the polymer (A) and a solvent, wherein the solvent is a compound represented by the following formula (b1) or a compound represented by the following formula (b2): The present invention provides a liquid crystal aligning agent containing at least one selected from the group consisting of compounds represented by the following formula:

（式（ｂ−１Ａ）中、Ｘ、Ｙは、それぞれ独立に−ＣＯＯ−又は−ＯＣＯ−であり、Ａ、Ｃ^１は、それぞれ独立に炭素数１〜６の１価の炭化水素基であり、Ｂは炭素数１〜１２の２価の炭化水素基である。）

（式（ｂ−１Ｂ）中、Ｒ^１、Ｒ^２は、それぞれ独立に炭素数３〜６のアルキル基であり、Ｒ^３はそれぞれ独立に水素原子又はメチル基であり、ｎ４は２又は３である。）

（式（ｂ１）中、Ｒは炭素数１〜３のアルキル基であり、ｎは０〜２の整数である。式（ｂ２）中、ｍは０〜２の整数である。）

(In the formula (b-1A), X and Y are each independently —COO— or —OCO—, and A and C ¹ are each independently a monovalent hydrocarbon group having 1 to 6 carbon atoms. , B is a divalent hydrocarbon group having 1 to 12 carbon atoms.)

(In the formula (b-1B), R ¹ and R ² are each independently an alkyl group having 3 to 6 carbon atoms, R ³ is each independently a hydrogen atom or a methyl group, and n4 is 2 or 3 is there.)

(In the formula (b1), R is an alkyl group having 1 to 3 carbon atoms, n is an integer of 0 to 2. In the formula (b2), m is an integer of 0 to 2.)

  The composition and the liquid crystal aligning agent contain at least one selected from the group consisting of the compound represented by the formula (b1) and the compound represented by the following formula (b2) as a solvent component, so that the coating property on the substrate is improved. (Printability) is good. Further, the composition of the present invention can be suitably used not only for liquid crystal alignment films, but also for insulating films and protective films for display elements and lighting devices.

  In one embodiment of the composition and the liquid crystal aligning agent, the solvent contains a compound represented by the formula (b-1A). In another aspect of the composition and the liquid crystal alignment agent, the solvent includes a compound represented by the above formula (b-1B). In these cases, even when stored in a low-temperature environment for a long period of time, precipitates are hardly generated in the composition or the alignment agent, and the storage stability is good. In addition, the applicability of the composition or the liquid crystal alignment agent to the substrate is good. Further, a liquid crystal display element exhibiting good display quality can be obtained even if the frame of the liquid crystal display element is narrowed.

  In the composition and the liquid crystal aligning agent of the present invention, the solvent contains a compound represented by the formula (b1) or (b2). In this case, the solubility of the polymer in the solvent is good. Further, the compound represented by the above formula (b1) or (b2) has a moderately high boiling point, so that when the composition or the liquid crystal aligning agent is printed on the substrate, the solvent evaporates from the printing machine. Can be suppressed. Therefore, the polymer component hardly precipitates on the printing press, and as a result, the printability (particularly, printability when printing is continuously performed for a long time, hereinafter also referred to as “long-term printability”) is good. Can be

（式（ｄ−１）中、Ｘ^１及びＸ^２は、それぞれ独立に、単結合、−Ｏ−、−Ｓ−、−ＯＣＯ−又は−ＣＯＯ−であり、Ｙ^１は、酸素原子又は硫黄原子であり、Ｒ^１１及びＲ^１２は、それぞれ独立に、炭素数１〜３のアルカンジイル基であり、Ｒ^８及びＲ^９は、それぞれ独立に、水素原子又は保護基である。ｎ１は０又は１であり、ｎ２及びｎ３は、ｎ１＝０の場合、ｎ２＋ｎ３＝２を満たす整数であり、ｎ１＝１の場合、ｎ２＝ｎ３＝１である。式（ｄ−２）中、Ｘ^３は、単結合、−Ｏ−又は−Ｓ−であり、ｍ１は０〜３の整数である。ｍ２は、ｍ１＝０の場合に１〜１２の整数であり、ｍ１が１〜３の整数の場合にｍ２＝２である。式（ｄ−３）中、Ｒ^３は、炭素数１〜１２の１価の炭化水素基であり、Ｒ^４は、水素原子、又は炭素数１〜１２の１価の炭化水素基であり、Ｒ^５及びＲ^６は、それぞれ独立に、水素原子又はメチル基である。式（ｄ−４）中、Ｘ^４及びＸ^５は、それぞれ独立に、単結合、−Ｏ−、−ＣＯＯ−又は−ＯＣＯ−であり、Ｒ^７は、炭素数１〜３のアルカンジイル基であり、Ａ^４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、ｋ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。式（ｄ−５）中、Ａ^５は単結合、炭素数１〜１２のアルカンジイル基又は炭素数１〜６のフルオロアルカンジイル基を示し、Ａ^６は−Ｏ−、−ＣＯＯ−、−ＯＣＯ−、−ＮＨＣＯ−、−ＣＯＮＨ−又は−ＣＯ−を示し、Ａ^７はステロイド骨格を有する１価の有機基を示す。） In the liquid crystal alignment agent of the present invention, the polymer (A) is derived from at least one diamine selected from the group consisting of compounds represented by the following formulas (d-1) to (d-5). It is preferable to include a polymer having a partial structure.

(In the formula (d-1), X ¹ and X ² are each independently a single bond, —O—, —S—, —OCO— or —COO—, and Y ¹ is an oxygen atom or a sulfur atom. R ¹¹ and R ¹² are each independently an alkanediyl group having 1 to 3 carbon atoms, R ⁸ and R ⁹ are each independently a hydrogen atom or a protecting group, and n1 is 0 or 1. , and the is n2 and n3, the case of n1 = 0, an integer satisfying n2 + n3 = 2, when the n1 = 1, in a n2 = n3 = 1. formula (d-2), ^{X 3} is a single A bond, —O— or —S—, m1 is an integer of 0 to 3. m2 is an integer of 1 to 12 when m1 = 0, and m2 when m1 is an integer of 1 to 3. = 2 In the formula (d-3), R ³ is a monovalent hydrocarbon group having 1 to 12 carbon atoms, and R ⁴ is a hydrogen atom or a carbon atom. R ⁵ and R ⁶ are each independently a hydrogen atom or a methyl group, and in formula (d-4), X ⁴ and X ⁵ are each independently a hydrogen atom or a methyl group. A single bond, —O—, —COO— or —OCO—, R ⁷ is an alkanediyl group having 1 to 3 carbon atoms, and A ⁴ is a single bond or an alkanediyl 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 k is 0 or 1, provided that a and b are 0 at the same time. In the formula (d-5), A ⁵ represents a single bond, an alkanediyl group having 1 to 12 carbon atoms or a fluoroalkanediyl group having 1 to 6 carbon atoms, and A ⁶ represents —O— or —COO. -, - OCO -, - NHCO -, - CONH- or -CO- indicates a monovalent organic ^{a 7} is having a steroid skeleton Are shown.)

  When at least a part of the polymer component of the liquid crystal aligning agent is the polymer (A) obtained by using the above-mentioned specific diamine, the above-mentioned effect is high and suitable.

  The liquid crystal aligning agent of the present invention has one primary amino group and a nitrogen-containing aromatic heterocycle in the molecule, and the primary amino group is a chain hydrocarbon group or an alicyclic hydrocarbon group. The bonded amine compound (C) may be further contained.

  When the liquid crystal aligning agent containing the polymer (A) as at least a part of the polymer component and the amine compound (C) as an additive is used, the liquid crystal aligning agent is stored in a low-temperature environment for a long time. In such a case, a problem may occur that the amine compound (C) precipitates in the alignment agent. In this regard, according to the liquid crystal aligning agent of the present configuration, by including at least one selected from the group consisting of the compound represented by the formula (b1) and the compound represented by the following formula (b2) as the solvent component Even when stored in a low-temperature environment for a long period of time, precipitates are hardly generated in the alignment agent, and the storage stability is good. In addition, the applicability of the liquid crystal aligning agent to the substrate is good.

  In a third aspect, the present invention provides a liquid crystal alignment film formed by the liquid crystal alignment agent of the present invention. According to a fourth aspect of the present invention, there is provided a liquid crystal display device including the liquid crystal alignment film. Since the liquid crystal alignment film is formed using a liquid crystal alignment agent having good printability, the yield of the liquid crystal display element can be increased.

FIG. 2 is a schematic configuration diagram of an FFS type liquid crystal cell. FIG. 4 is a schematic plan view of a top electrode used for manufacturing a liquid crystal display element by a photo-alignment method. (A) is a top view of the top electrode, and (b) is a partially enlarged view of the top electrode. FIG. 4 is a diagram showing four drive electrodes.

≪Composition and liquid crystal alignment agent≫
The composition and the liquid crystal aligning agent according to the present embodiment include, as a polymer component, at least one polymer (A) selected from the group consisting of polyamic acid, polyimide, and polyamic acid ester. Is dispersed or dissolved in a solvent to prepare a liquid composition. The composition according to the present embodiment is preferably a liquid crystal alignment agent.

<< Polymer (A) >>
<Polyamic acid>
The polyamic acid in the present embodiment can be obtained by reacting a tetracarboxylic dianhydride with a diamine.

（式（ｔ−１）中、Ｘ^７、Ｘ^８、Ｘ^９及びＸ^１０は、それぞれ独立に、単結合又はメチレン基であり、ｊは１〜３の整数である。）
で表される化合物などを；
芳香族テトラカルボン酸二無水物として、例えばピロメリット酸二無水物などを；それぞれ挙げることができるほか、特開２０１０−９７１８８号公報に記載のテトラカルボン酸二無水物を用いることができる。なお、テトラカルボン酸二無水物は、上記のものを１種単独で又は２種以上組み合わせて使用することができる。 [Tetracarboxylic dianhydride]
Examples of the tetracarboxylic dianhydride used for synthesizing the polyamic acid include aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, and aromatic tetracarboxylic dianhydride. Specific examples of these include:
Examples of the aliphatic tetracarboxylic dianhydride include 1,2,3,4-butanetetracarboxylic dianhydride and the like;
Examples of the alicyclic tetracarboxylic dianhydride include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic 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- Without 1,2-dicarboxylic acid Things, 3,5,6-tricarboxy-2-carboxymethyl norbornane -2: 3,5: 6-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^{2, 6]} undecane -3,5,8,10-tetraone, cyclohexanetetracarboxylic dianhydride, the following formula (t-1)

(In the formula (t-1), X ⁷ , X ⁸ , X ⁹ and X ¹⁰ are each independently a single bond or a methylene group, and j is an integer of 1 to 3.)
A compound represented by;
As the aromatic tetracarboxylic dianhydride, for example, pyromellitic dianhydride and the like can be mentioned; in addition, a tetracarboxylic dianhydride described in JP-A-2010-97188 can be used. The above-mentioned tetracarboxylic dianhydrides can be used alone or in combination of two or more.

  Here, as the compound represented by the above formula (t-1), for example, bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic dianhydride, bicyclo [4.3. 0] nonane-2,4,7,9-tetracarboxylic dianhydride, bicyclo [4.4.0] decane-2,4,7,9-tetracarboxylic dianhydride, bicyclo [4.4. 0] decane-2,4,8,10-tetracarboxylic dianhydride, tricyclo [6.3.0.0 <2,6>] undecane-3,5,9,11-tetracarboxylic dianhydride And the like. Among the compounds represented by the formula (t-1), bicyclo [3.3.0] octane-2,4,6,8 is preferred from the viewpoint of increasing the stability of liquid crystal alignment in liquid crystal alignment film applications. -Tetracarboxylic dianhydride is preferred.

  Among the above, as the tetracarboxylic dianhydride used for the synthesis of the polyamic acid, the compound represented by the above formula (t-1), 2,3,5-tricarboxycyclopentylacetic dianhydride, 1,2 It is preferable to use at least one compound selected from the group consisting of 2,3,4-cyclobutanetetracarboxylic dianhydride and pyromellitic dianhydride (hereinafter also referred to as a specific tetracarboxylic dianhydride). . When the specific tetracarboxylic dianhydride is used, the total amount of the specific tetracarboxylic dianhydride used is 10 mol% or more based on the total amount of the tetracarboxylic dianhydride used for the synthesis of the polyamic acid. And more preferably 20 to 100 mol%. In addition, a polymer having a partial structure derived from the specific tetracarboxylic dianhydride can be obtained by polymerization including the specific tetracarboxylic dianhydride in the monomer composition.

[Diamine]
As the diamine used in the synthesis of the polyamic acid, a compound represented by the above formula (d-1), a compound represented by the above formula (d-2), a compound represented by the above formula (d-3), At least one diamine selected from the group consisting of the compound represented by the formula (d-4) and the compound represented by the formula (d-5) (hereinafter, also referred to as “specific diamine”). Is preferred.

(Compound represented by Formula (d-1))
In the formula (d-1), examples of the alkanediyl group having 1 to 3 carbon atoms of R ¹¹ and R ¹² include a methylene group, an ethylene group, a propane-1,2-diyl group, and a propane-1,3-diyl. A propane-2,3-diyl group. Of these, a methylene group, an ethylene group or a propane-1,3-diyl group is preferred.
X ¹ and X ² are a single bond, —O—, —S—, —OCO— or —COO—. Incidentally, ^{X 1} and ^{X 2} may be the same or different. Among these, a single bond, -O- or -S- is preferable.
Y ¹ is an oxygen atom or a sulfur atom. Preferably, it is an oxygen atom.
The protecting groups for R ⁸ and R ⁹ are preferably groups that can be eliminated by heat, and examples thereof include carbamate-based protecting groups, amide-based protecting groups, imide-based protecting groups, and sulfonamide-based protecting groups. As the protecting groups for R ⁸ and R ⁹ , carbamate-based protecting groups are particularly preferable, and specific examples thereof include a tert-butoxycarbonyl group, a benzyloxycarbonyl group, a 1,1-dimethyl-2-haloethyloxycarbonyl group, , 1-dimethyl-2-cyanoethyloxycarbonyl group, 9-fluorenylmethyloxycarbonyl group, allyloxycarbonyl group, 2- (trimethylsilyl) ethoxycarbonyl group and the like. Of these, a tert-butoxycarbonyl group is particularly preferred in that it has high heat desorption properties and the amount of deprotected portions remaining in the film can be reduced.

Two primary amino groups of the compound represented by the formula (d-1) may be bonded to the same benzene ring when n1 = 0, or may be bonded to two different benzene rings one by one. It may be. On the other hand, when n1 = 1, two primary amino groups are respectively bonded to different benzene rings.
The bonding position of the primary amino group on the benzene ring is not particularly limited. For example, when there is one primary amino group on the benzene ring, the bonding position may be any of the 2-position, 3-position, and 4-position with respect to the other group, and may be at the 3-position or 4-position. It is preferably, and more preferably 4-position. When there are two primary amino groups on the benzene ring, the bonding position is, for example, 2,4-position, 2,5-position, or the like with respect to other groups. Is preferred.
The hydrogen atom on the benzene ring to which the primary amino group is bonded is a monovalent hydrocarbon group having 1 to 10 carbon atoms or a monovalent hydrocarbon group in which at least one hydrogen atom on the hydrocarbon group is substituted with a fluorine atom. It may be substituted with a group or a fluorine atom. Examples of the monovalent hydrocarbon group in this case include an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, and an aryl group having 5 to 10 carbon atoms ( A phenyl group, a tolyl group, etc.) and an aralkyl group having 5 to 10 carbon atoms (eg, a benzyl group).

  In addition, in this specification, "hydrocarbon group" is meant to include a chain hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. In addition, the “chain hydrocarbon group” means a linear hydrocarbon group and a branched hydrocarbon group that have only a chain structure without a cyclic structure in the main chain. The chain structure may be saturated or unsaturated. The “alicyclic hydrocarbon group” means a hydrocarbon group containing only an alicyclic hydrocarbon structure as a ring structure and not containing an aromatic ring structure. However, it is not necessary to be constituted only by the structure of the alicyclic hydrocarbon, but also includes those having a chain structure in a part thereof. “Aromatic hydrocarbon group” means a hydrocarbon group containing an aromatic ring structure as a ring structure. However, it is not necessary to include only an aromatic ring structure, and a part thereof may include a chain structure or an alicyclic hydrocarbon structure.

  Preferable specific examples of the compound represented by the above formula (d-1) include, as compounds having n1 = 0, for example, 4,4′-diaminodiphenylamine, 2,4-diaminodiphenylamine; and n1 = 1. As the compound, for example, 1,3-bis (4-aminobenzyl) urea, 1,3-bis (4-aminophenethyl) urea, 1,3-bis (3-aminobenzyl) urea, 1- (4-aminobenzyl) ) -3- (4-Aminophenethyl) urea, 1,3-bis (2- (4-aminophenoxy) ethyl) urea, 1,3-bis (3- (4-aminophenoxy) propyl) urea, 3-bis (4-aminobenzyl) thiourea, 1,3-bis (2-aminobenzyl) urea, 1,3-bis (2-aminophenethyl) urea, 1,3-bis (2- (2- Mino benzoyloxy) ethyl) urea, 1,3-bis (3- (2-amino-benzoyloxy) propyl) urea or the like; may be mentioned, respectively. In addition, as the compound represented by the above formula (d-1), these compounds can be used alone or in combination of two or more.

(Compound represented by Formula (d-2))
In the above formula (d-2), X ³ is a single bond, —O— or —S—, preferably a single bond or —O—.
When m1 = 0, m2 is an integer of 1 to 12. In this case, from the viewpoint of improving the heat resistance of the obtained polymer, m2 is preferably 1 to 10, and more preferably 1 to 8. In the application of the liquid crystal alignment film, m1 is preferably 0 from the viewpoint of improving rubbing resistance while maintaining good liquid crystal alignment, and m1 is 1 from the viewpoint of reducing the pretilt angle of liquid crystal molecules. It is preferably an integer of up to 3.
The bonding position of the primary amino group on the benzene ring is not particularly limited, but each primary amino group is preferably at the 3- or 4-position with respect to the other group, and more preferably at the 4-position. . The hydrogen atom on the benzene ring to which the primary amino group is bonded is a monovalent hydrocarbon group having 1 to 10 carbon atoms, or a hydrogen atom in which at least one hydrogen atom on the hydrocarbon group is substituted with a fluorine atom. It may be substituted with a valent group or a fluorine atom.

  Preferred specific examples of the compound represented by the above formula (d-2) include, for example, bis (4-aminophenoxy) methane, bis (4-aminophenoxy) ethane, bis (4-aminophenoxy) propane, bis (4 -Aminophenoxy) butane, bis (4-aminophenoxy) pentane, bis (4-aminophenoxy) hexane, bis (4-aminophenoxy) heptane, bis (4-aminophenoxy) octane, bis (4-aminophenoxy) nonane , Bis (4-aminophenoxy) decane, bis (4-aminophenyl) methane, bis (4-aminophenyl) ethane, bis (4-aminophenyl) propane, bis (4-aminophenyl) butane, bis (4- Aminophenyl) pentane, bis (4-aminophenyl) hexane, bis (4-aminophenyl) ) Heptane, bis (4-aminophenyl) octane, bis (4-aminophenyl) nonane, bis (4-aminophenyl) decane, 1,3-bis (4-aminophenylsulfanyl) propane, 1,4-bis ( 4-aminophenylsulfanyl) butane and the like. In addition, as the compound represented by the above formula (d-2), these exemplified compounds can be used alone or in combination of two or more.

(Compound represented by Formula (d-3))
In the formula (d-3), R ³ is a monovalent hydrocarbon group having 1 to 12 carbon atoms. Specific examples of R ³ include methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, t- butyl group, a pentyl group, a hexyl group, an octyl group, and decyl groups; vinyl group And alkenyl groups such as allyl group; cycloalkyl groups such as cyclopentyl group and cyclohexyl group; aryl groups such as phenyl group and tolyl group; aralkyl groups such as benzyl group. R ³ preferably has 1 to 6 carbon atoms, and more preferably 1 to ³ carbon atoms. R ³ is preferably a chain hydrocarbon group, more preferably a chain hydrocarbon group containing a carbon-carbon double bond, and even more preferably an alkenyl group.

R ⁴ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms. Examples of the hydrocarbon group include a chain hydrocarbon group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and an aromatic hydrocarbon group having 5 to 12 carbon atoms. specific examples thereof include the groups exemplified in the description of the R ^3. R ⁴ is preferably a hydrogen atom or a chain hydrocarbon group having 1 to 12 carbon atoms. Further, the hydrocarbon group for R ⁴ preferably has 1 to 6 carbon atoms, and more preferably 1 to 3 carbon atoms.
R ⁵ and R ⁶ are each independently a hydrogen atom or a methyl group, and preferably both are hydrogen atoms.

  In the diaminophenyl group of the formula (d-3), the bonding position of the two primary amino groups is not particularly limited, but is 2,4-position or 2-position with respect to the group having an N-allyl structure bonded to a benzene ring. , 5-position is preferred, and 2,4-position is more preferred. The hydrogen atom on the benzene ring to which the primary amino group is bonded is a monovalent hydrocarbon group having 1 to 10 carbon atoms or a monovalent hydrocarbon group in which at least one hydrogen atom on the hydrocarbon group is substituted with a fluorine atom. Or a fluorine atom.

Preferred specific examples of the compound represented by the formula (d-3) include, for example, 2,4-diamino-N, N-diallylaniline, 2,5-diamino-N, N-diallylaniline, and the following formula (d -3-1) to (d-3-3). In addition, the compound represented by the above formula (d-3) can be used alone or in combination of two or more.

(Compound represented by Formula (d-4))
In Formula (d-4), examples of the divalent group represented by “—X ⁴ — (R ⁷ —X ⁵ ) _k —” include an alkanediyl group having 1 to 3 carbon atoms, * —O—, and *. —COO— or * —O—C ₂ H ₄ —O— (provided that the bond with “*” bonds to the diaminophenyl group) is preferable.
The group “—C _c H _{2c + 1} ” is preferably linear, and specific examples thereof include, for example, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, and an n-hexyl. Group, n-heptyl group, n-octyl 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, n-eicosyl group and the like.
Two primary amino groups in di aminophenyl group is preferably 2,4-position or 3,5-position relative to the group ^{"X 4",} and more preferably 2,4-position. The hydrogen atom on the benzene ring to which the primary amino group is bonded is a monovalent hydrocarbon group having 1 to 10 carbon atoms, or a monovalent hydrocarbon group in which at least one hydrogen atom on the hydrocarbon group is substituted with a fluorine atom. Or a fluorine atom.

Preferred specific examples of the compound represented by the formula (d-4) include, for example, compounds represented by the following formulas (d-4-1) to (d-4-12). it can.

(Compound represented by Formula (d-5))
In Formula ^{(d-5), A} 5 represents a single bond, indicates the alkanediyl group or a fluoro C 1 to C 6 alkanediyl group having 1 to 12 carbon atoms, ^{A 6} is -O -, - COO -, - OCO -, - NHCO -, - CONH- or -CO- indicates, ^{a 7} represents a monovalent organic group having a steroid skeleton.
The alkanediyl group having 1 to 12 carbon atoms in the ^{A 5} in the above formula (d-5), preferably alkanediyl group having 1 to 4 carbon atoms, a methylene group, an ethylene group, 1,3-propanediyl, 1 , 4-butanediyl group is more preferred. The fluoro alkanediyl group having 1 to 6 carbon atoms, preferably perfluoro alkanediyl group having 1 to 4 carbon atoms, -CF ₂ -, perfluoro ethylene group, 1,3-perfluoro-propanediyl, 1,4 -A perfluorobutanediyl group is more preferred.
A ⁶ is preferably -O-.
The steroid skeleton in the A ^7, Shikuropentano - perhydro phenanthridine consisting Ren core structure or a carbon - one or more than one carbon bond refers to a structure in which a double bond. The monovalent organic group having a steroid skeleton preferably has 17 to 40 carbon atoms.

  Preferred specific examples of the compound represented by the formula (d-5) include 1-cholesteryloxymethyl-2,4-diaminobenzene, 1-cholesteryloxymethyl-3,5-diaminobenzene, 1- (1-cholesteryloxy-1,1-difluoromethyl) -2,4-diaminobenzene, 1- (1-cholesteryloxy-1,1 -Difluoromethyl) -3,5-diaminobenzene, 1- (1-cholestaniloxy-1,1-difluoromethyl) -2,4-diaminobenzene, 1- (1-cholestaniloxy-1,1-difluoro Methyl) -3,5-diaminobenzene, 3- (2,4-diaminophenylmethoxy) -4,4-dimethylcholestane, 3- (1- (2,4-diaminophenyl)- , 1-Difluoromethoxy) -4,4-dimethylcholestane, 3- (3,5-diaminophenylmethoxy) -4,4-dimethylcholestane, 3- (1- (3,5-diaminophenyl) -1 , 1-Difluoromethoxy) -4,4-dimethylcholestane, 3-((2,4-diaminophenyl) methoxy) choran-24-acid hexadecyl, 3- (1- (2,4-diaminophenyl) -1 Hexadecyl, 1,1-difluoromethoxy) colan-24-acid, hexadecyl 3-((3,5-diaminophenyl) methoxy) choran-24-acid, 3- (1- (3,5-diaminophenyl) -1,1 -Difluoromethoxy) choran-24-acid hexadecyl, 3- (2,4-diaminophenylmethoxy) choran-24-acid stearyl, 3- (1- (2,4-di Stearyl minophenyl) -1,1-difluoromethoxy) choran-24-acid, stearyl 3- (3,5-diaminophenylmethoxy) choran-24-acid, 3- (1- (3,5-diaminophenyl) -1 , 1-Difluoromethoxy) cholane-24-acid stearyl, 1-cholesteryloxy-2,4-diaminobenzene, cholesteryl 3,5-diaminobenzoate, 1-cholestaniloxy-2,4-diaminobenzene and 3, It is preferable to use at least one member selected from the group consisting of cholestanyl 5-diaminobenzoate, and among these, 1-cholesteryloxy-2,4- Diaminobenzene, cholesteryl 3,5-diaminobenzoate, 1-cholestaniloxy-2,4-diaminobe It is particularly preferred to use at least one selected from the group consisting of Zen and 3,5-diaminobenzoic acid cholestanyl.

  In synthesizing the polyamic acid, the specific diamine can be appropriately selected from the above compounds according to the driving mode of the liquid crystal display element to be produced. Specifically, by using the compound represented by the formula (d-1) as the specific diamine, a liquid crystal aligning agent suitable for an FFS (Fringe Field Switching) type liquid crystal display device can be manufactured. . Further, by using at least one selected from the group consisting of the compound represented by the formula (d-2) and the compound represented by the formula (d-3), a TN (Twisted Nematic) type liquid crystal display is provided. A liquid crystal alignment agent suitable for a device can be produced, and at least one selected from the group consisting of a group represented by the formula (d-4) and a compound represented by the formula (d-5) is used. By doing so, a liquid crystal aligning agent suitable for a vertical alignment type liquid crystal display device can be manufactured.

(Other diamines)
As the diamine used for synthesizing the polyamic acid, a compound other than the above-mentioned specific diamine (other diamine) may be used. Examples of such other diamines include aliphatic diamines, alicyclic diamines, aromatic diamines, and diaminoorganosiloxanes. Specific examples of these other diamines include aliphatic diamines such as metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, and 1,3-bis (aminomethyl) cyclohexane. Alicyclic diamines such as 1,4-diaminocyclohexane and 4,4′-methylenebis (cyclohexylamine);

As the aromatic diamine, for example, p-phenylenediamine, 4,4'-diaminodiphenyl sulfide, 1,5-diaminonaphthalene, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-bis (tri (Fluoromethyl) -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) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4 ′-(p -Phenylenediisopropylidene) bisaniline, 4,4 ′-(m-phenylenediisopropylidene) bisaniline, 1,4-bi (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminoacridine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N, N′-bis (4-amino Phenyl) -benzidine, N, N'-bis (4-aminophenyl) -N, N'-dimethylbenzidine, 1,4-bis- (4-aminophenyl) -piperazine, 1- (4-aminophenyl)- 2,3-dihydro-1,3,3-trimethyl-1H-indene-5-amine, 1- (4-aminophenyl) -2,3-dihydro-1,3 -Trimethyl-1H-indene-6-amine, 4- (4'-trifluoromethoxybenzoyloxy) cyclohexyl-3,5-diaminobenzoate, 4- (4'-trifluoromethylbenzoyloxy) cyclohexyl-3, 5-diaminobenzoate, 1,1-bis (4-((aminophenyl) methyl) phenyl) -4-butylcyclohexane, 1,1-bis (4-((aminophenyl) methyl) phenyl) -4-heptylcyclohexane , 1,1-bis (4-((aminophenoxy) methyl) phenyl) -4-heptylcyclohexane, 1,1-bis (4-((aminophenyl) methyl) phenyl) -4- (4-heptylcyclohexyl) Cyclohexane, 4-aminobenzylamine, 3-aminobenzylamine, 2,2-bis [4- (4 Etc. aminophenoxy) phenyl] propane;
Examples of the diaminoorganosiloxane include, for example, 1,3-bis (3-aminopropyl) -tetramethyldisiloxane, and the diamine described in JP-A-2010-97188 can be used. In addition, these other diamines can be used alone or in combination of two or more.

  In the case where the polymer (A) includes a polymer having a partial structure derived from a specific diamine (hereinafter, also referred to as “specific polymer”), the content ratio of the specific polymer depends on the composition from the viewpoint of printability. 50 parts by weight or more, preferably 70 parts by weight or more, more preferably 80 parts by weight or more, based on 100 parts by weight of the total amount of the polymer component contained in the product or the liquid crystal aligning agent. More preferably, it is particularly preferably at least 90 parts by weight.

（式（ｅ１−１）及び式（ｅ１−２）中、Ｒ^２０は、ハロゲン原子、炭素数１〜１０のアルキル基又は炭素数１〜１０のアルコキシ基であり、Ｚ^１は、単結合、酸素原子又は炭素数１〜３のアルカンジイル基である。ｒ２、ｒ５及びｒ６は、それぞれ独立に１又は２の整数であり、ｒ１、ｒ３及びｒ４は、それぞれ独立に０〜２の整数であり、ｒ７及びｒ８は、それぞれ独立に、ｒ７＋ｒ８＝２を満たす０〜２の整数である。但し、ｒ３＋ｒ５＋ｒ７≦５であり、ｒ４＋ｒ６＋ｒ８≦５である。式中、複数のＲ^２０が存在する場合、それらＲ^２０は独立して上記定義を有する。） When the liquid crystal aligning agent according to the present embodiment contains a specific amine compound (C) described in detail below as an additive, the polymer (A) is a diamine having a carboxyl group (hereinafter, “diamine having a carboxyl group”). ) Is preferable. In the case of a polyamic acid, for example, such a polymer can be obtained by using a carboxyl group-containing diamine as at least a part of the other diamine used for the synthesis of the polyamic acid. The carboxyl group-containing diamine is preferably an aromatic diamine, and specific examples include compounds represented by the following formulas (e1-1) and (e1-2).

(In the formula (e1-1) and the formula (e1-2), R ²⁰ is a halogen atom, an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms, Z ¹ is a single bond, An oxygen atom or an alkanediyl group having 1 to 3 carbon atoms, r2, r5 and r6 are each independently an integer of 1 or 2, and r1, r3 and r4 are each independently an integer of 0 to 2. , r7 and r8 are each independently an integer of 0 to 2 satisfying r7 + r8 = 2. However, a r3 + r5 + r7 ≦ 5, in r4 + r6 + r8 is ≦ 5. equation, when a plurality of ^{R 20} are present, they R ²⁰ independently has the above definition.)

In the formula (e1-1) and the formula (e1-2), examples of the alkyl group having 1 to 10 carbon atoms for R ²⁰ include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, and a heptyl group. Octyl group, nonyl group, decyl group, etc., which may be linear or branched. Examples of the alkoxy group having 1 to 10 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, and a hexyloxy group.
The alkanediyl group having 1 to 3 carbon atoms in Z ^1, may be, for example, a methylene group, an ethylene group, and trimethylene group.
r1, r3 and r4 are preferably 0 or 1, and more preferably 0.

  Specific examples of the carboxyl group-containing diamine include, as compounds represented by the following formula (e1-1), for example, 3,5-diaminobenzoic acid, 2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, and the like. As a compound represented by the following formula (e1-2), for example, 4,4′-diaminobiphenyl-3,3′-dicarboxylic acid, 4,4′-diaminobiphenyl-2,2′-dicarboxylic acid, 3'-diaminobiphenyl-4,4'-dicarboxylic acid, 3,3'-diaminobiphenyl-2,4'-dicarboxylic acid, 4,4'-diaminodiphenylmethane-3,3'-dicarboxylic acid, 4,4 ' -Diaminobiphenyl-3-carboxylic acid, 4,4'-diaminodiphenylmethane-3-carboxylic acid, 4,4'-diaminodiphenylethane-3,3'-dicarboxylic acid, 4,4 ' It can be mentioned; diaminodiphenyl ethane-3-carboxylic acid, 4,4'-diaminodiphenyl ether 3,3'-dicarboxylic acid, 4,4'-like diaminodiphenyl ether 3-carboxylic acid.

The amount of the specific diamine used when synthesizing the polyamic acid can be arbitrarily set according to the compound used. For example, when the compound represented by the above formula (d-1) is used, the amount used is preferably 10 mol% or more, more preferably 30 mol% or more, based on all diamines. . When the compound represented by the formula (d-2) is used, the amount of the compound is 10 mol% or more based on all diamines from the viewpoint of imparting a low tilt alignment angle to liquid crystal molecules. It is more preferably at least 30 mol%, even more preferably at least 50 mol%.
When the compound represented by the formula (d-3) is used, the amount used is preferably 5 mol% or more based on all diamines from the viewpoint of improving the stability of the voltage holding ratio. , And more preferably at least 10 mol%.

When using at least one selected from the group consisting of the compound represented by the above formula (d-4) and the compound represented by the above formula (d-5), the use thereof is preferred from the viewpoint of imparting good orientation. The amount (when two or more compounds are used, the total amount) is preferably at least 5 mol%, more preferably at least 10 mol%, based on all diamines. As the specific diamine, one of the compounds exemplified above can be used alone or in combination of two or more.
When a carboxyl group-containing diamine is used as the other diamine, the proportion of the carboxyl group-containing diamine to the total diamine is preferably 5 mol% or more, more preferably 10 to 90 mol%, and more preferably 10 to 90 mol%. ~ 70 mol% is more preferred.

（式（ｍ−１）中、Ｒ^２３は、炭素数６〜２０のアルキル基又はアルコキシ基であり、Ｒ^２４は２価の有機基であり、ｈは０又は１である。） With respect to a liquid crystal aligning agent for a TN-type liquid crystal display element, in the synthesis of a polyamic acid, together with tetracarboxylic dianhydride and diamine, the following formula ( The monoamine represented by m-1) may be used.

(In the formula (m-1), R ²³ is an alkyl group or an alkoxy group having 6 to 20 carbon atoms, R ²⁴ is a divalent organic group, and h is 0 or 1.)

In the formula (m-1), examples of the alkyl group having 6 to 20 carbon atoms for R ²³ include a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, a dodecyl group, a tridecyl group, a tetradecyl group, and a pentadecyl group. , A hexadecyl group, a heptadecyl group, an octadecyl group, a nonadecyl group, an eicosyl group and the like, which may be linear or branched. The alkoxy group having 6 to 20 carbon atoms, for example, groups in which an alkyl group having 6 to 20 carbon atoms exemplified above is bonded to an oxygen atom ^{(-OR 23),} and the like.

Examples of the divalent organic group for R ²⁴ include a divalent hydrocarbon group such as a divalent chain hydrocarbon group, an alicyclic hydrocarbon group and an aromatic hydrocarbon group, and a carbon-carbon bond in a hydrocarbon group. In between, a group having a functional group such as —O—, —CO—, —COO—, and —S—, a heterocyclic-containing group, and the like can be given. Here, specific examples of the divalent hydrocarbon group include, as chain hydrocarbon groups, for example, a methylene group, an ethylene group, a propanediyl group, a butanediyl group, a pentanediyl group, a hexanediyl group, a heptanediyl group, an octanediyl group, Nonanediyl group, decanediyl group, undecanediyl group, dodecanediyl group, tridecanediyl group, tetradecanediyl group, pentadecanediyl group, octadecanediyl group, icosylene group, vinylene group, propenediyl group, butenediyl group, pentenediyl group, ethynylene group, propynylene group Alicyclic hydrocarbon groups such as cyclopropylene, cyclobutylene, cyclopentylene, cyclohexylene, cyclohexenylene, cycloheptylene, cyclooctylene, cyclononylene, cyclodeylene; Len group, cycloundecylene group, cyclododecylene group, cyclotridecylene group, cyclotetradecylene group, cyclopentadecylene group, cyclooctadecylene group, cycloicosylene group, bicyclohexylene group, norbornylene group, adamantylene group, etc. And examples of the aromatic hydrocarbon group include, for example, a phenylene group and a biphenylene group. R ²⁴ is particularly preferably a chain hydrocarbon group, an alicyclic hydrocarbon group or an aromatic hydrocarbon group.

  Preferred specific examples of the monoamine represented by the above formula (m-1) include, for example, n-hexylamine, n-octylamine, n-decylamine, n-dodecylamine, n-hexadecylamine, 1,3-dimethyl Aliphatic monoamines such as butylamine, 1,5-dimethylhexylamine and 2-ethylhexylamine; p-aminophenylhexane, p-aminophenyloctane, p-aminophenyldodecane, p-aminophenylhexadecane, p-aminophenoxyoctane And aromatic monoamines such as p-aminophenoxydodecane and p-aminophenoxyhexadecane;

From the viewpoint of preventing the monoamine released in the manufactured liquid crystal cell from affecting the display characteristics, the use ratio of the monoamine is a mole of the tetracarboxylic dianhydride, b mole of the diamine, and c of the monoamine. It is preferable that “2 (ab) ≧ c> 0” is satisfied in the case of mol.
The monoamine represented by the above formula (m-1) may be reacted and polymerized with the reaction product after the reaction of the tetracarboxylic dianhydride with the diamine, The three components of anhydride, diamine and monoamine may be simultaneously reacted and polymerized.

[Molecular weight regulator]
When synthesizing the polyamic acid, a terminal-modified polymer may be synthesized using an appropriate molecular weight regulator together with the tetracarboxylic dianhydride and the diamine as described above. By using such a terminal-modified polymer, the coating properties (printability) of the liquid crystal alignment agent can be further improved without impairing the effects of the present invention.

Examples of the molecular weight regulator include an acid monoanhydride, a monoamine compound and a monoisocyanate compound. Specific examples thereof include, as an acid monoanhydride, for example, maleic anhydride, phthalic anhydride, itaconic anhydride, n-decylsuccinic anhydride, n-dodecylsuccinic anhydride, n-tetradecylsuccinic Acid anhydrides, n-hexadecyl succinic anhydrides and the like; monoamine compounds such as aniline, cyclohexylamine, n-butylamine, compounds represented by the above formula (m-1); monoisocyanate compounds; Examples include phenyl isocyanate and naphthyl isocyanate.
The proportion of the molecular weight modifier used is preferably 20 parts by weight or less, more preferably 10 parts by weight or less, based on 100 parts by weight of the total of tetracarboxylic dianhydride and diamine used.

<Synthesis of polyamic acid>
The ratio of the tetracarboxylic dianhydride and the diamine used for the synthesis reaction of the polyamic acid is such that the acid anhydride group of the tetracarboxylic dianhydride is 0.2 to 2 with respect to 1 equivalent of the amino group of the diamine. The ratio which becomes equivalent is preferable, and the ratio which becomes 0.3 to 1.2 equivalent is more preferable.
The synthesis reaction of the polyamic acid is preferably performed in an organic solvent. The reaction temperature at this time is preferably from -20C to 150C, more preferably from 0C to 100C. The reaction time is preferably 0.1 to 24 hours, more preferably 0.5 to 12 hours.

Here, examples of the organic solvent include aprotic polar solvents, phenol solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons, hydrocarbons, and the like.
Specific examples of these organic solvents include, for example, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, N-ethyl-2-pyrrolidone, N, N -Dimethylacetamide, N, N-dimethylformamide, dimethylsulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide, and the like; as the phenolic solvent, for example, phenol, m-cresol, xylenol, halogenated phenol and the like ;

Examples of the alcohol include methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, and ethylene glycol monomethyl ether; and examples of the ketone include acetone and Methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and the like; as the above-mentioned ester, for example, ethyl lactate, butyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl methoxypropionate, ethylethoxypropionate, diethyl oxalate, malon Diethyl acid, isoamylpropionate, isoamylisobutyrate and the like;
Examples of the ether include diethyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-n-butyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, and diethylene glycol monomethyl ether. , Diethylene glycol monomethyl ether acetate, tetrahydrofuran, diisopentyl ether and the like;
As the halogenated hydrocarbon, for example, dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene and the like; As the hydrocarbon, for example, hexane, heptane, octane, Benzene, toluene, xylene and the like; In addition, the specific solvent (B) can be used.

  Among these organic solvents, one or more selected from the group consisting of aprotic polar solvents and phenolic solvents (organic solvent A), or one or more selected from organic solvent A, and alcohols, ketones, esters, It is preferable to use a mixture with at least one selected from the group consisting of ethers, halogenated hydrocarbons and hydrocarbons (organic solvent B). In the latter case, the proportion of the organic solvent B used is preferably 50% by weight or less, more preferably 40% by weight or less, and still more preferably 30% by weight, based on the total amount of the organic solvent A and the organic solvent B. % Or less. The amount (a) of the organic solvent used is such that the total amount (b) of the tetracarboxylic dianhydride and the diamine is 0.1 to 50% by weight based on the total amount (a + b) of the reaction solution. Is preferred.

  As described above, a reaction solution obtained by dissolving the polyamic acid is obtained. This reaction solution may be directly used for preparation of a composition such as a liquid crystal alignment agent, or may be used for preparation of a liquid crystal alignment agent or the like after isolating the polyamic acid contained in the reaction solution. The polyamic acid may be purified and then used for preparing a liquid crystal aligning agent and the like. When the polyamic acid is subjected to dehydration ring closure to form a polyimide, the reaction solution may be subjected to the dehydration ring closure reaction as it is, or the polyamic acid contained in the reaction solution may be isolated and then subjected to the dehydration ring closure reaction. Alternatively, the isolated polyamic acid may be purified and then subjected to a dehydration ring closure reaction. Isolation and purification of the polyamic acid can be performed according to a known method.

<Polyimide>
The polyimide according to this embodiment can be obtained by dehydrating and ring-closing the polyamic acid synthesized as described above to imidize the polyamic acid.

  The polyimide may be a complete imidized product obtained by dehydrating and ring-closing all of the amic acid structures that the precursor polyamic acid had, and dehydrating and ring-closing only a part of the amic acid structure to form an amic acid structure. It may be a partially imidized compound having an imide ring structure. The imidation ratio of the polyimide in the present embodiment is preferably 30% or more, more preferably 40 to 99%, and still more preferably 50 to 99%. The imidation ratio is a percentage of the number of imide ring structures to the total number of amic acid structures and imide ring structures of the polyimide. Here, a part of the imide ring may be an isoimide ring.

The dehydration and ring closure of the polyamic acid is preferably carried out by heating the polyamic acid or by dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydration ring-closing catalyst to the solution, and heating as necessary. . Of these, the latter method is preferred.
In the above method of adding a dehydrating agent and a dehydration ring-closing catalyst to a solution of a polyamic acid, as the dehydrating agent, for example, an acid anhydride such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride can be used. The amount of the dehydrating agent used is preferably 0.01 to 20 mol per 1 mol of the amic acid structure of the polyamic acid. As the dehydration ring-closing catalyst, for example, tertiary amines such as pyridine, collidine, lutidine, and triethylamine can be used. The amount of the dehydration ring-closing catalyst used is preferably 0.01 to 10 mol per 1 mol of the dehydrating agent used. Examples of the organic solvent used for 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 from 0 to 180 ° C, more preferably from 10 to 150 ° C. The reaction time is preferably from 1.0 to 120 hours, more preferably from 2.0 to 30 hours.

  Thus, a reaction solution containing the polyimide is obtained. This reaction solution may be directly used for preparing a composition such as a liquid crystal alignment agent, or may be used for preparing a liquid crystal alignment agent or the like after removing the dehydrating agent and the dehydration ring-closing catalyst from the reaction solution. The separated polyimide may be used for preparing a liquid crystal aligning agent or the like after separation, or the isolated polyimide may be purified and then used for preparing a liquid crystal aligning agent or the like. These purification operations can be performed according to a known method.

<Polyamic acid ester>
The polyamic acid ester contained in the composition such as the liquid crystal alignment agent of the present embodiment includes, for example, [I] a polyamic acid obtained by the above synthesis reaction, a hydroxyl group-containing compound, a halide, an epoxy group-containing compound, and the like. It can be obtained by a method of synthesizing by reacting, a method of reacting a tetracarboxylic acid diester with a diamine, and a method of reacting a tetracarboxylic acid diester dihalide with a diamine.

  Here, examples of the hydroxyl group-containing compound used in the method [I] include alcohols such as methanol, ethanol, and propanol; and phenols such as phenol and cresol. Examples of the halide include, for example, methyl bromide, ethyl bromide, stearyl bromide, methyl chloride, stearyl chloride, 1,1,1-trifluoro-2-iodoethane, and the like. For example, propylene oxide and the like can be mentioned. The tetracarboxylic diester used in the method [II] can be obtained, for example, by ring-opening the tetracarboxylic dianhydride exemplified in the above synthesis of the polyamic acid using the above alcohol. The tetracarboxylic diester dihalide used in the method [III] can be obtained by reacting the tetracarboxylic diester obtained as described above with a suitable chlorinating agent such as thionyl chloride. As the diamine used in the methods [II] and [III], the specific diamine and the other diamines exemplified in the above synthesis of the polyamic acid can be used, and it is preferable to include the specific diamine. The polyamic acid ester 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.

<Solution viscosity and weight average molecular weight>
The polyamic acid, polyimide, and polyamic acid ester obtained as described above preferably have a solution viscosity of 10 to 800 mPa · s when a solution having a concentration of 10% by weight is used, and preferably have a solution viscosity of 15 to 500 mPa. More preferably, it has a solution viscosity of s. Note that 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). , Measured at 25 ° C. using an E-type rotational viscometer.
The reduced viscosity is not particularly limited as long as a uniform coating film can be formed, but is preferably 0.05 to 3.0 dl / g, and more preferably 0.1 to 2.5 dl / g. Is more preferable, and more preferably 0.3 to 1.5 dl / g.
The polyamic acid, polyimide, and polyamic acid ester contained in the composition such as the liquid crystal alignment agent according to the present embodiment have a weight average molecular weight of 500 to 100,000 in terms of polystyrene measured by gel permeation chromatography (GPC). It is preferably, and more preferably 1,000 to 50,000.

≪Solvent≫
The composition and the liquid crystal aligning agent according to this embodiment include, as solvent components, a compound represented by the formula (b-1A), a compound represented by the formula (b-1B), and a compound represented by the formula (b1). And the specific solvent (B) which is at least one selected from the group consisting of the compounds represented by the formula (b2). By including such a specific solvent (B) in a composition such as a liquid crystal aligning agent, the applicability of the liquid crystal aligning agent or the like to a substrate can be improved.

<1> Compound represented by the above formula (b-1A) The compound represented by the above formula (b-1A) is contained in a composition such as a liquid crystal aligning agent to coat the liquid crystal aligning agent or the like on a substrate. And storage stability of the liquid crystal aligning agent and the like can be improved. Further, good display quality can be maintained even when the frame of the liquid crystal display element is narrowed.

In the compound represented by the formula (b-1A), X and Y are each independently -COO- or -OCO-. A and C ¹ are each independently a monovalent hydrocarbon group having 1 to 6 carbon atoms, preferably a linear or branched alkyl group having 1 to 4 carbon atoms. B is a divalent hydrocarbon group having 1 to 12 carbon atoms, preferably an alkylene group having 1 to 6 carbon atoms.

Examples of the compound represented by the above formula (b-1A) include the following. In addition, the compound represented by the above formula (b-1A) may be used alone or in combination of two or more.

  Here, for example, the liquid crystal alignment agent is usually stored in an extremely low temperature environment (for example, at −15 ° C.) from the time of manufacture to the time of shipment in order to prevent deterioration of polyamic acid or polyimide. However, a precipitate may be generated in the solution in the liquid crystal aligning agent stored at a low temperature for a long time. Further, once deposited, the precipitate is hardly redissolved, which may cause a problem such as poor printing in the manufacturing process of the liquid crystal display element. Although the cause of the generation of such precipitates is not clear, it is assumed that butyl cellosolve, which is generally used as a solvent component of the liquid crystal aligning agent, is one of the causes. Therefore, there is a need to find a new organic solvent instead of butyl cellosolve as a solvent for improving the applicability to a substrate.

  2. Description of the Related Art A liquid crystal display is manufactured by disposing a pair of substrates on each of which a liquid crystal alignment film is formed, and disposing a liquid crystal between the pair of substrates opposed to each other. At this time, the pair of substrates are bonded together using a sealing agent such as an epoxy resin. In a touch panel type display panel represented by a smartphone or a tablet PC, an attempt has been made to narrow the frame in order to make the movable area of the touch panel wider and to downsize the liquid crystal panel (element). As the frame of the liquid crystal panel becomes narrower, display unevenness may be visually recognized around the sealant, and the display quality is not sufficiently satisfactory. In order to achieve higher definition and longer life of the liquid crystal display, a liquid crystal display element in which display unevenness around such a sealant is hardly visually recognized (high bezel unevenness resistance) is required.

  In this regard, the compound represented by the above formula (b-1A) is useful as a new organic solvent replacing butyl cellosolve. Specifically, the liquid crystal aligning agent containing the compound represented by the formula (b-1A) as a solvent component has good storage stability for long-term low-temperature storage and good coating properties on a substrate, and has a narrower frame. It corresponds to.

<2> Compound represented by the above formula (b-1B) The compound represented by the above formula (b-1B) is contained in a composition such as a liquid crystal aligning agent, so that a liquid crystal aligning agent or the like is applied to a substrate. And storage stability of the liquid crystal aligning agent and the like can be improved. Further, good display quality can be maintained even when the frame of the liquid crystal display element is narrowed.

The compound represented by the above formula ^{(b-1B), R 1} ~R 2 are each independently an alkyl group having 3 to 6 carbon atoms, preferably an alkyl group having 4-6 carbon atoms. R ³ is each independently a hydrogen atom or a methyl group. n4 is 2 or 3.
If n4 is 2, or the two R ³ are both hydrogen atoms, it is preferred that one is a hydrogen atom and the other is a methyl group, and particularly preferably both hydrogen atoms.
When n4 is 3, all ^three R ³ are preferably hydrogen atoms, or two are preferably hydrogen atoms and one is a methyl group, and particularly preferably all are hydrogen atoms.

Examples of the compound represented by the above formula (b-1B) include the following. In addition, the compound represented by the above formula (b-1B) may be used alone or in a combination of two or more.

  The compound represented by the above formula (b-1B) is useful as a new organic solvent replacing butyl cellosolve, similarly to the above (b-1A). Specifically, the liquid crystal aligning agent containing the compound represented by the formula (b-1B) as a solvent component has good storage stability for long-term low-temperature storage, good coating properties on a substrate, and a narrow frame. It corresponds to.

<3> Compound represented by Formula (b1) or Formula (b2) The compound represented by Formula (b1) or Formula (b2) has good solubility in polyamic acid and polyimide, and has a boiling point of Moderately high. Therefore, by using such a compound as at least a part of the solvent, at the time of printing a composition such as a liquid crystal aligning agent on a substrate, it is possible to suppress volatilization of the solvent from the printing press, and the Precipitation of the polymer component becomes difficult. As a result, printability (particularly long-term printability) can be improved. In addition, since the boiling point of the solvent is not too high, when preheating (prebaking) is performed after printing, the amount of solvent remaining in the coating film after preheating can be reduced. Therefore, it is possible to suppress the dust from adhering to the surface of the coating film after the preliminary heating, thereby suppressing a decrease in product yield.

(Compound represented by the above formula (b1))
In the compound represented by the formula (b1), R is an alkyl group having 1 to 3 carbon atoms, and preferably an alkyl group having 1 or 2 carbon atoms. n is an integer of 0 to 2, and is preferably 1 or 2.
Examples of the compound represented by the above formula (b1) include the following. In addition, the compound represented by the above formula (b1) may be used alone or in combination of two or more.

(Compound represented by the above formula (b2))
In the compound represented by the formula (b2), m is an integer of 0 to 2, and is preferably 1 or 2.
Examples of the compound represented by the above formula (b2) include the following. In addition, the compound represented by the above formula (b2) can be used alone or in combination of two or more.

  Note that the specific solvent (B) contained in the composition or the liquid crystal aligning agent of the present embodiment is a compound represented by the above formula (b-1A), a compound represented by the above formula (b-1B), Or only one of the compounds represented by the formula (b1) or (b2). Further, two or more of these may be included in combination.

(Other solvents)
The composition such as the liquid crystal alignment agent of the present embodiment preferably further contains, as a solvent component, another solvent other than the specific solvent (B). Examples of the other solvent include a solvent capable of dissolving the polymer (A) (hereinafter, also referred to as a “first solvent”) and a poor solvent for the polymer (A) other than the specific solvent (B). Organic solvents and the like can be mentioned.

  The first solvent may be a good solvent for the polymer (A), and specific preferred examples thereof include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, and N-pentyl-2. -Pyrrolidone, 3-methoxy-N, N-dimethylpropionamide, N, N, 2-trimethylpropionamide, 3-butoxy-N, N-dimethylpropionamide, γ-butyrolactone, γ-butyrolactam, N, N-dimethyl Formamide, N, N-dimethylacetamide, 1,3-dimethyl-2-imidazolidinone, N-ethyl-2-pyrrolidone, dimethylsulfoxide, tetramethylurea, hexamethylphosphortriamide, m-cresol and the like. The first solvent may be used alone or in combination of two or more.

  Examples of the poor solvent for the polymer (A) and the organic solvent other than the specific solvent (B) (hereinafter also referred to as “other poor solvents”) include ethylene glycol monomethyl ether, butyl lactate, and acetic acid. Butyl, 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 monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate Diethylene glycol monoethyl ether acetate, dipropylene glycol monomethyl ether (DPM), diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, ethylene carbonate, propylene carbonate, diacetone alcohol, diethylene glycol diethyl ether, diisopentyl ether, propylene glycol di Acetate and the like can be mentioned. These organic solvents can be used alone or in combination of two or more. Hereinafter, the group consisting of the other poor solvent and the specific solvent (B) is also referred to as “second solvent”.

The content ratio of the specific solvent (B) in the liquid crystal aligning agent is preferably 1 to 70% by weight based on the total amount of the solvent contained in the liquid crystal aligning agent. When the content of the specific solvent (B) is less than 1% by weight, the effect of improving the applicability to the substrate is hardly obtained, and when it exceeds 70% by weight, the polymer component tends to precipitate. The content ratio of the specific solvent (B) is more preferably 5 to 70% by weight, and further preferably 10 to 65% by weight.
In addition, the content ratio of the first solvent is preferably 5% by weight or more, more preferably 5% by weight, based on the total amount of the solvent contained in the liquid crystal alignment agent, from the viewpoint of suppressing the precipitation of the polymer (A). It is at least 10% by weight, more preferably at least 15% by weight. In addition, the upper limit of the content ratio of the first solvent is preferably 99% by weight based on the total amount of the solvent contained in the liquid crystal aligning agent, from the viewpoint of suitably obtaining the effect of the addition of the specific solvent (B). % Or less, more preferably 95% by weight or less, and even more preferably 85% by weight or less.

The content ratio of the other poor solvent is preferably 70% by weight or less, more preferably 60% by weight or less, and still more preferably 50% by weight or less based on the total amount of the solvent contained in the liquid crystal aligning agent. And particularly preferably 30% by weight or less.
The ratio of the first solvent to the second solvent should be 0.03 times (weight) or more the amount of the second solvent with respect to the amount of the first solvent from the viewpoint of improving the applicability to the substrate. And more preferably 0.05 times (weight) or more. Further, from the viewpoint of suppressing the precipitation of the polymer, it is preferably 2.5 times (weight) or less, more preferably 2.0 times (weight) or less.

  It is preferable that the liquid crystal aligning agent according to the present embodiment does not substantially contain butyl cellosolve as a solvent. In this specification, "substantially free of butyl cellosolve" means that the content ratio of butyl cellosolve is preferably 5% by weight or less, more preferably 3% by weight or less, based on the total amount of the solvent contained in the liquid crystal aligning agent. % By weight, more preferably 0.5% by weight or less.

《Other ingredients》
The composition such as the liquid crystal alignment agent according to the present embodiment contains the polymer (A) and the solvent as described above, but may contain other components as needed. Examples of such other components include other polymers other than the polymer (A), a compound having at least one epoxy group in a molecule (hereinafter, referred to as an “epoxy group-containing compound”), a functional silane compound, The amine compound (C) and the like can be mentioned.

[Other polymers]
These other polymers can be used to improve solution properties and electrical properties. Examples of such other polymers include polyesters, polyamides, cellulose derivatives, polyacetals, polystyrene derivatives, poly (styrene-phenylmaleimide) derivatives, and poly (meth) acrylates. When the other polymer is added to the liquid crystal aligning agent, its compounding ratio is preferably 50% by weight or less, more preferably 0.1 to 40% by weight, based on the total amount of the polymer components in the liquid crystal aligning agent. Preferably, it is more preferably 0.1 to 30% by weight.

[Epoxy group-containing compound]
The epoxy group-containing compound can be used to improve the adhesion of the liquid crystal alignment film to the substrate surface. Here, as the epoxy group-containing compound, 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, , 6-hexanediol diglycidyl ether, glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, N, N, N ', N'-tetraglycidyl-m-xylenediamine , 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ', N'-tetraglycidyl-4,4'-diaminodi Enirumetan, N, N-diglycidyl - benzylamine, N, N-diglycidyl - aminomethyl cyclohexane, N, N-diglycidyl - and cyclohexyl amine.
When these epoxy group-containing compounds are added to the liquid crystal aligning agent, the compounding ratio is preferably 40 parts by weight or less, and preferably 0.1 to 30 parts by weight, based on 100 parts by weight of the total polymer contained in the liquid crystal aligning agent. Parts are more preferred.

[Functional silane compound]
The functional silane compound can be used for the purpose of improving the printability of the liquid crystal alignment agent. Examples of such a functional silane compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, and 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 azanonanoate, N-benzyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, glycidoxymethyltrimethoxysilane, 2-glycidoxyethyltrimethoxysilane, 3-glycid Xypropyltrimethoxysilane and the like can be mentioned.
When these functional silane compounds are added to the liquid crystal aligning agent, the mixing ratio thereof is preferably 2 parts by weight or less, more preferably 0.02 to 0.2 parts by weight, based on 100 parts by weight of the polymer in total.

[Amine compound (C)]
The amine compound (C) has one primary amino group and a nitrogen-containing aromatic heterocyclic ring, and the primary amino group is bonded to a chain hydrocarbon group or an alicyclic hydrocarbon group. It is a compound having a structure. The amine compound (C) can be used for the purpose of improving the electrical characteristics of the liquid crystal display element (for example, the voltage holding ratio and the rate of relaxation of the residual charge) in the liquid crystal alignment film application.

  The nitrogen-containing aromatic heterocycle in the amine compound (C) may be any aromatic ring containing at least one nitrogen atom in the ring skeleton. Therefore, the ring skeleton may contain only a nitrogen atom as a hetero atom, or may contain a nitrogen atom and a hetero atom (an oxygen atom, a sulfur atom, or the like) other than the nitrogen atom. Specific examples of the nitrogen-containing aromatic heterocyclic ring include, for example, a pyrrole ring, an imidazole ring, a pyrazole ring, a triazole ring, a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring, an indole ring, a benzimidazole ring, a purine ring, and a quinoline ring. , Isoquinoline ring, naphthyridine ring, quinoxaline ring, phthalazine ring, triazine ring, azepine ring, diazepine ring, acridine ring, phenazine ring, phenanthroline ring, oxazole ring, thiazole ring, carbazole ring, thiadiazole ring, benzothiazole ring, phenothiazine ring, Oxadiazole ring and the like. Further, the nitrogen-containing aromatic heterocyclic ring may be one in which a substituent is introduced into a carbon atom constituting the above-described ring. Examples of the substituent include a halogen atom, an alkyl group, and an alkoxy group.

  In the amine compound (C), the chain hydrocarbon group preferably has 1 to 20 carbon atoms, more preferably has 1 to 15 carbon atoms, and still more preferably has 1 to 10 carbon atoms. The chain hydrocarbon group may be linear or branched, and may be saturated or unsaturated. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and even more preferably 3 to 10 carbon atoms.

（式（ｃ−１）中、Ａ^１は、鎖状炭化水素基又は脂環式炭化水素基を有する２価の有機基であり、Ａ^２は、窒素含有芳香族複素環である。ただし、式中の１級アミノ基は、Ａ^１が有する鎖状炭化水素基又は脂環式炭化水素基に結合している。） As the amine compound (C), a compound represented by the following formula (c-1) can be preferably used.

(In the formula (c-1), A ¹ is a divalent organic group having a chain hydrocarbon group or an alicyclic hydrocarbon group, and A ² is a nitrogen-containing aromatic heterocyclic ring. primary amino groups in the formula are attached to a linear hydrocarbon group or an alicyclic hydrocarbon group a ¹ has.)

In the above formula (c-1), examples of the divalent organic group for A ¹ include a divalent chain hydrocarbon group, a divalent alicyclic hydrocarbon group, —O—R ²¹ —, and —CO 2. —R ²¹ — (where R ²¹ is a divalent chain hydrocarbon group or an alicyclic hydrocarbon group). In addition, the divalent organic group may have -O-, -NH-, -CO-O-, between carbon-carbon bonds in a divalent chain hydrocarbon group or a divalent alicyclic hydrocarbon group. _{-CO-NH -, - CO -} , - S -, - S (O) 2 -, - Si (CH 3) 2 -, - O-Si (CH 3) 2 -, - O-Si (CH 3) _2- O-, a divalent group having an aromatic hydrocarbon group such as a phenylene group, a heterocyclic group such as a pyridinylene group; at least a divalent chain hydrocarbon group or a divalent alicyclic hydrocarbon group; A divalent group in which one hydrogen atom is substituted with a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, an aromatic hydrocarbon group such as a phenyl group, a hydroxyl group, a halogenated alkyl group, and the like; It may be. Specific examples of the divalent chain hydrocarbon group and alicyclic hydrocarbon group in A ¹ is a description of R ²⁴ in the formula (m-1) is applied.

Among these, A ¹ is preferably a divalent organic group having a chain hydrocarbon group, and more preferably a divalent chain hydrocarbon group. A ¹ preferably has 1 to 20 carbon atoms, more preferably has 1 to 15 carbon atoms, and still more preferably has 1 to 10 carbon atoms. The above description applies for nitrogen-containing aromatic heterocycle A ^2.

Specific examples of the amine compound (C) include, for example, compounds represented by the following formulas (c-1-1) to (c-1-32). In addition, as an amine compound (C), one of these can be used alone or in combination of two or more.

  When the above-mentioned amine compound (C) is added to the liquid crystal aligning agent, the mixing ratio thereof is 1 part by weight based on 100 parts by weight of the total polymer, from the viewpoint of suitably obtaining the effect of the addition of the amine compound (C). Parts or more, more preferably 2 parts by weight or more. In addition, from the viewpoint of not impairing the stability of the liquid crystal aligning agent, the amount is preferably 20 parts by weight or less, more preferably 15 parts by weight or less, based on 100 parts by weight of the polymer in total.

  In addition, as other additives to be contained in the liquid crystal alignment agent, in addition to the above, a compound having at least one oxetanyl group in a molecule, an antioxidant, and the like can be given. These use ratios can be appropriately selected according to the additives used, as long as the effects of the present invention are not impaired.

When the amine compound (C) is contained as an additive in the liquid crystal aligning agent according to the present embodiment, the polymer (A) is preferable in that the electrical characteristics of the liquid crystal display element can be suitably improved. It is preferable that at least a part of the compound has a carboxyl group. In addition, the number of carboxyl groups of the polymer (A) is preferably 0.1 to 3 on average, and preferably 0.3 to 2 per repeating unit of the polymer (A). Is more preferable, and it is still more preferable that the number is 0.5 to 1.8.
The method for adjusting the number of carboxyl groups contained in the polymer (A) is not particularly limited. A method of adjusting the carboxyl group content of the diamine to be used, and the like. Further, it may be performed by using the above (i) and (ii) together. From the viewpoint of increasing the degree of freedom of the imidation ratio of the polymer (A), the method (ii) is preferably used.

  When the polymer (A) having a carboxyl group and the amine compound (C) are contained in a liquid crystal aligning agent, the mixing ratio of the amine compound (C) is 1 mol of the carboxyl group of the polymer (A). , 0.01 to 2 mol, more preferably 0.05 to 1 mol, even more preferably 0.08 to 0.8 mol.

  The solid content concentration (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) of the liquid crystal aligning agent according to the present embodiment is appropriately 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 according to the present embodiment is applied to the substrate surface as described below, and is preferably heated to form a coating film serving as a liquid crystal alignment film or a coating film serving as a liquid crystal alignment film. At this time, if the solid content concentration is less than 1% by weight, it is difficult to obtain a good liquid crystal alignment film because the thickness of the coating film is too small. On the other hand, if the solid concentration exceeds 10% by weight, the thickness of the coating film becomes excessively large, making it difficult to obtain a good liquid crystal alignment film, and the viscosity of the liquid crystal alignment agent increases, resulting in poor coating characteristics. Becomes

  The particularly preferable range of the solid content concentration differs depending on the method used when applying the liquid crystal aligning agent to the substrate. For example, when the spin coating method is used, the solid content concentration is particularly preferably in the range of 1.5 to 4.5% by weight. In the case of the offset 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 using the ink jet method, it is particularly preferable that the solid content concentration is in the range of 1 to 8% by weight, and thereby the solution viscosity is in the range of 3 to 20 mPa · s. The temperature at the time of preparing the liquid crystal aligning agent of the present embodiment is preferably from 10 to 50C, more preferably from 20 to 30C.

≪Liquid crystal alignment film and liquid crystal display device≫
The liquid crystal alignment film according to the present embodiment is formed by the liquid crystal alignment agent prepared as described above. Further, the liquid crystal display element according to the present embodiment includes a liquid crystal alignment film formed using the liquid crystal alignment agent. The driving mode to which the liquid crystal display element is applied is not particularly limited, and can be applied to various driving modes such as a TN mode, an STN mode, an IPS mode, an FFS mode, a VA mode, and an MVA mode. Hereinafter, a method for manufacturing the liquid crystal display element according to the present embodiment will be described, and in the description, a method for manufacturing the liquid crystal alignment film will be described.

  The liquid crystal display element according to the present embodiment can be manufactured, for example, by the following steps (1) to (3). In the step (1), a substrate to be used differs depending on a desired driving mode. Steps (2) and (3) are common to each drive mode.

[Step (1): Formation of coating film]
First, the liquid crystal aligning agent of the present embodiment is applied on a substrate, and then the coated surface is heated to form a coating film on the substrate.
(1-1) In the case of manufacturing a TN-type, STN-type or VA-type liquid crystal display element, two substrates provided with a patterned transparent conductive film are paired, and the respective transparent conductive film forming surfaces are formed on the two substrates. The liquid crystal aligning agent according to the present embodiment is preferably applied by an offset printing method, a spin coating method, a roll coater method, or an inkjet printing method, respectively. Here, as the substrate, for example, a transparent substrate made of glass such as float glass or soda glass; or a plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, or poly (alicyclic olefin) can be used. As the transparent conductive film provided on one surface of a substrate, NESA film (US PPG registered trademark) made of tin oxide (SnO _2), indium oxide - such as an ITO film made of tin oxide _{(In 2} O 3 -SnO ₂₎ the Can be used. In order to obtain a patterned transparent conductive film, for example, a method of forming a pattern by photo-etching after forming a transparent conductive film without a pattern, a method of using a mask having a desired pattern when forming the transparent conductive film, or the like is used. be able to. In applying the liquid crystal aligning agent, a functional silane compound, a functional titanium compound and a functional titanium compound are coated on the surface of the substrate where the coating is to be formed in order to further improve the adhesion between the substrate surface and the transparent conductive film and the coating. A pretreatment for applying a compound or the like in advance may be performed.

  After the application of the liquid crystal alignment agent, preheating (prebake) is preferably performed for the purpose of preventing the applied alignment agent from dripping. The prebaking temperature is preferably from 30 to 200 ° C, more preferably from 40 to 150 ° C, and particularly preferably from 40 to 100 ° C. The pre-bake time is preferably from 0.25 to 10 minutes, more preferably from 0.5 to 5 minutes. Thereafter, a baking (post-bake) step is performed for the purpose of completely removing the solvent and, if necessary, thermally imidizing the amic acid structure present in the polymer. The firing (post-baking) temperature is preferably from 80 to 300 ° C, more preferably from 120 to 250 ° C. The post-bake time is preferably from 5 to 200 minutes, more preferably from 10 to 100 minutes. The thickness of the film thus formed is preferably from 0.001 to 1 μm, more preferably from 0.005 to 0.5 μm.

  (1-2) In the case of 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 according to the present embodiment is applied to one surface of the opposite substrate that has not been coated, and then each applied surface is heated to form a coating film. The material used for the substrate and the transparent conductive film, the coating method, the heating conditions after the coating, the patterning method for the transparent conductive film or the metal film, the pretreatment of the substrate, and the preferable film thickness of the formed coating film are described above. This is the same as (1-1). As the metal film, for example, a film made of a metal such as chromium can be used.

  In both cases (1-1) and (1-2), after applying a liquid crystal aligning agent on the substrate, the organic solvent is removed to form a coating film serving as an alignment film. At this time, when the polymer contained in the liquid crystal aligning agent is a polyamic acid or an imidized polymer having an imide ring structure and an amic acid structure, by further heating after forming the coating film, The dehydration ring-closing reaction may proceed to form a more imidized coating film.

[Step (2): treatment for imparting alignment ability]
When manufacturing a TN-type, STN-type, IPS-type or FFS-type liquid crystal display element, a process of imparting liquid crystal alignment capability to the coating film formed in the above step (1) is performed. Thereby, the alignment ability of the liquid crystal molecules is imparted to the coating film to form a liquid crystal alignment film. As the treatment, a rubbing treatment in which a coating film is rubbed in a certain direction with a roll wrapped with a cloth made of, for example, nylon, rayon, cotton, or the like, a photo-alignment treatment for irradiating polarized light or non-polarized radiation to the coating film, or the like. Is mentioned. On the other hand, in the case of manufacturing a VA type liquid crystal display element, the coating film formed in the above step (1) can be used as it is as a liquid crystal alignment film. Good.

In the photo-alignment treatment, ultraviolet rays and visible rays including light having a wavelength of, for example, 150 to 800 nm can be used as radiation applied to the coating film. When the radiation is polarized, it may be linearly polarized or partially polarized. When the radiation used is linearly polarized light or partially polarized light, the irradiation may be performed in a direction perpendicular to the substrate surface, may be performed in an oblique direction, or may be performed in combination. When irradiating unpolarized radiation, the direction of irradiation is oblique.
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 and the like can be used. Ultraviolet rays in a preferable wavelength range can be obtained by means 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 , and more preferably 300 to 20,000 J / m ² . Light irradiation on the coating film may be performed while heating the coating film in order to increase reactivity. The temperature at the time of heating is usually 30 to 250 ° C, preferably 40 to 200 ° C, and more preferably 50 to 150 ° C.

  In addition, the liquid crystal alignment film after the rubbing treatment is further irradiated with ultraviolet light to a part of the liquid crystal alignment film to change a pretilt angle in a partial region of the liquid crystal alignment film, or to perform a process on one surface of the liquid crystal alignment film. After forming a resist film on the portion, a rubbing process is performed in a different direction from the previous rubbing process, and then a process of removing the resist film is performed so that the liquid crystal alignment film has a different liquid crystal alignment ability 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 be suitably used for a PSA (Polymer sustained alignment) liquid crystal display element.

[Step (3): Construction of Liquid Crystal Cell]
A liquid crystal cell is manufactured by preparing two substrates on each of which a liquid crystal alignment film is formed as described above, and disposing a liquid crystal between the two substrates that are opposed to each other. In order to manufacture a liquid crystal cell, for example, the following two methods can be used.
The first method is a conventionally known method. First, two substrates are opposed to each other with a gap (cell gap) therebetween so that the liquid crystal alignment films face each other, and the peripheral portions of the two substrates are bonded to each other using a sealant. After filling and filling the liquid crystal into the cell gap defined by the above, the liquid crystal cell is manufactured by sealing the filling hole. The second method is a method called 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 at predetermined predetermined locations on the liquid crystal alignment film surface. After that, the other substrate is adhered so that the liquid crystal alignment film faces each other, 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 producing a liquid crystal cell. . In either case, the liquid crystal cell manufactured as described above is further heated to a temperature at which the used liquid crystal takes an isotropic phase, and then gradually cooled to room temperature, whereby the flow orientation at the time of filling the liquid crystal is improved. It is desirable to remove it.

As the sealant, for example, an epoxy resin containing aluminum oxide spheres as a curing agent and a spacer can be used.
Examples of the liquid crystal include a nematic liquid crystal and a smectic liquid crystal, and among them, a nematic liquid crystal is preferable, for example, a Schiff base liquid crystal, an azoxy liquid crystal, a biphenyl liquid crystal, a phenylcyclohexane liquid crystal, an ester liquid crystal, a terphenyl liquid crystal, and biphenyl. A cyclohexane-based liquid crystal, a pyrimidine-based liquid crystal, a dioxane-based liquid crystal, a bicyclooctane-based liquid crystal, a cubane-based liquid crystal, or the like can be used. In addition, cholesteric liquid crystals such as cholesteryl chloride, cholesteryl nonaate and cholesteryl carbonate; chiral agents sold under the trade names “C-15” and “CB-15” (manufactured by Merck) A ferroelectric liquid crystal such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate may be added and used.

  Then, a liquid crystal display device can be obtained by attaching a polarizing plate to the outer surface of the liquid crystal cell. The polarizing plate bonded to the outer surface of the liquid crystal cell may be a polarizing plate in which a polarizing film called “H film” in which polyvinyl alcohol is stretched and oriented and absorbs iodine is sandwiched by a cellulose acetate protective film or the H film itself. Can be mentioned. When the rubbing process is performed on the coating film, the two substrates are arranged to face each other so that the rubbing directions of the coating films are at a predetermined angle, for example, orthogonal or antiparallel.

  The liquid crystal display device according to the present embodiment can be effectively applied to various devices, for example, a clock, a portable game, a word processor, a notebook computer, a car navigation system, a camcorder, a PDA, a digital camera, a mobile phone, It can be used for display devices such as smartphones, various monitors, and liquid crystal televisions.

  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 imidation ratio of polyimide in the polymer solution and the solution viscosity of the polymer solution were measured by the following methods.
[Imidation rate of polyimide]
The polyimide solution was poured into pure water, and the obtained precipitate was sufficiently dried at room temperature under reduced pressure, dissolved in deuterated dimethyl sulfoxide, and ¹ H-NMR was measured at room temperature using tetramethylsilane as a reference substance. From the obtained ¹ H-NMR spectrum, the imidation ratio [%] was determined by the following equation (x).
Imidation ratio [%] = (1−A ¹ / A ² × α) × 100 (x)
(In the formula (x), A ¹ is the peak area derived from the proton of the NH group, which appears near the chemical shift of 10 ppm, A ² is the peak area derived from the other protons, and α is the precursor of the polymer (polyamic acid ) Is the number ratio of other protons to one proton of the NH group.)
[Solution viscosity of polymer solution]
The solution viscosity (mPa · s) of the polymer solution was measured at 25 ° C. using an E-type viscometer.
[Reference Example 1]

[Reference Example 1A]
In a 50 ml four-necked flask equipped with a stirrer and a nitrogen introducing tube, 0.60 g (2.0 mmol) of 1,3-bis (4-aminophenethyl) urea (BAPU) as a diamine and p-phenylenediamine (p-PDA) were added. 1.95 g (18.0 mmol) was added, 30 g of N-methyl-2-pyrrolidone (NMP) was added, and the mixture was stirred and dissolved while supplying nitrogen. While stirring this diamine solution, 3.70 g (18.9 mmol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA) was added as tetracarboxylic dianhydride, and the solid content concentration was further increased. NMP was added to 12 wt%, and the mixture was stirred at room temperature for 4 hours under a nitrogen atmosphere to obtain a solution of polyamic acid (PA-1).
To this polyamic acid solution, NMP and a compound represented by the following formula (ba) (hereinafter, referred to as “compound (ba)”) as a specific solvent (B) were added, and the solvent composition was NMP: compound. A liquid crystal aligning agent (S1A) was prepared so that (ba) = 60: 40 (weight ratio) and the polyamic acid concentration was 6.0% by weight.

[Reference Example 2A]
19.2 g (0.098 mol) of CBDA as a tetracarboxylic dianhydride and 24.2 g (0.1 mol) of 1,5-bis (4-aminophenoxy) pentane as a diamine were dissolved in 343.5 g of NMP. Allowed to react for hours. The polymerization reaction proceeded easily and uniformly, and polyamic acid (PA-2) was obtained. To the NMP solution of the polyamic acid (PA-2), NMP and a compound represented by the following formula (bb) as a specific solvent (B) (hereinafter, referred to as “compound (bb)”) are added. A liquid crystal aligning agent (S2A) was prepared such that the solvent composition was NMP: compound (bb) = 50: 50 (weight ratio) and the polyamic acid concentration was 6.0% by weight.

[Reference Example 3A]
22.42 g (0.1 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as tetracarboxylic dianhydride and 18.73 g of 4,4′-diaminodiphenylamine (4,4 ′ DADPA) as diamine 0.094 mol) was mixed in 345.1 g of NMP and reacted at room temperature for 5 hours. The polymerization reaction proceeded easily and uniformly, and polyamic acid (PA-3) was obtained. To the NMP solution of the polyamic acid (PA-3), NMP and a compound represented by the following formula (bc) as a specific solvent (B) (hereinafter, referred to as “compound (bc)”) are added. A liquid crystal aligning agent (S3A) was prepared so that the solvent composition was NMP: compound (bc) = 80: 20 (weight ratio) and the polyamic acid concentration was 6.0% by weight.

[Reference Example 4A]
As a diamine, 6.5 g (0.06 mol) of p-PDA and 4- (4-trans-n-heptylcyclohexyl) phenoxy) -1,3-diaminobenzene (PCH7DAB, represented by the above formula (d-4-3)) 15.22 g (0.04 mol) of NMP was dissolved in 165 g of NMP, and 19.41 g (0.099 mol) of CBDA as tetracarboxylic dianhydride was added thereto, and reacted at room temperature for 24 hours to obtain polyamic acid (PA). -4) was obtained. The weight average molecular weight (Mw) of the obtained polyamic acid (PA-4) was 40,000. To 30 g of this solution, NMP and a compound represented by the following formula (bd) as a specific solvent (B) (hereinafter, referred to as “compound (bd)”) were added, and the solvent composition was NMP: compound (b). -D) = 80: 20 (weight ratio)) and a liquid crystal aligning agent (S4A) having a concentration of 4.5% by weight was prepared.

[Reference Example 5A]
1.46 g (13.5 mmol) of p-PDA as a diamine and 0.78 g (1.50 mmol) of cholestanyl 3,5-diaminobenzoate were mixed in 20.0 g of NMP, and CBDA was used as a tetracarboxylic dianhydride. While adding 85 g (14.5 mmol), 24.7 g of NMP was added and reacted at 25 ° C. for 5 hours to obtain a solution containing polyamic acid (PA-5). Next, to 40.0 g of the obtained polyamic acid solution, NMP and a compound represented by the following formula (be) as a specific solvent (B) (hereinafter, referred to as “compound (be)”) are added, and A liquid crystal aligning agent (S5A) was prepared such that the solvent composition was NMP: compound (be) = 75: 25 (weight ratio) and the polyamic acid concentration was 4.0% by weight.

[Reference Example 6A]
2.58 g (13.1 mmol) of CBDA as a tetracarboxylic dianhydride and 5.0 g (13.1 mmol) of PCH7DAB as a diamine are dissolved in 43 g of NMP, and the mixture is stirred and reacted at 20 ° C. for 4 hours to obtain a polyamic acid (PA-6). ) Was obtained. Next, in the NMP solution of the obtained polyamic acid (PA-6), NMP and a compound represented by the following formula (b-f) as the specific solvent (B) (hereinafter, referred to as compound (b-f)). Was added to prepare a liquid crystal alignment agent (S6A) such that the solvent composition was NMP: compound (b-f) = 35: 65 (weight ratio) and the solid content concentration was 3.0% by weight.

[Reference Example 7A]
8.724 g (0.04 mol) of pyromellitic dianhydride (PMDA) as tetracarboxylic dianhydride, 2.877 g (0.0266 mol) of p-PDA as diamine, and 4.567 g (0.012 mol) of PCH7DAB in NMP91 The reaction was performed at room temperature for 3 hours in 0.6 g to prepare a solution containing polyamic acid (PA-7). To 25 g of this polyamic acid solution, NMP and a compound represented by the following formula (bg) as a specific solvent (B) (hereinafter, referred to as compound (bg)) were added, and the solvent composition was NMP: compound ( bg) = 60: 40 (weight ratio), and a liquid crystal aligning agent (S7A) was prepared so as to have a solid content concentration of 5.0% by weight.

[Reference Example 8A]
14.64 g (0.072 mol) of 2,4-diamino-N, N-diallylaniline as a diamine, 2.96 g (0.016 mol) of n-dodecylamine as a monoamine, and 15.69 g of CBDA as a tetracarboxylic dianhydride (0.08 mol) was reacted in 300 g of NMP at room temperature for 4 hours to prepare a solution containing a polyamic acid intermediate (PA-8). To the NMP solution of this polyamic acid intermediate, NMP and a compound represented by the following formula (bh) as a specific solvent (B) (hereinafter, referred to as compound (bh)) are added, and the solvent composition is NMP. : Compound (bh) = 60: 40 (weight ratio), liquid crystal aligning agent (S8A) having a solid content of 6.0% by weight was prepared.

[Reference Example 9A]
4.50 g (0.018 mol) of bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic acid 2: 4,6: 8-dianhydride (BODA) as tetracarboxylic dianhydride After reacting 0.68 g (0.0018 mol) of PCH7DAB and 1.75 g (0.0162 mol) of p-PDA as a diamine in 39.3 g of NMP at room temperature, the mixture was further reacted at 40 ° C. for 43 hours. NMP was added to 42 g of this polyamic acid solution to prepare a 1% by weight solution, and 4.18 g of acetic anhydride and 6.48 g of pyridine were added as imidation catalysts, and the mixture was reacted at room temperature for 30 minutes and at 120 ° C. for 2 hours. I let it. This solution was poured into a large amount of methanol, and the obtained white precipitate was separated by filtration and dried to obtain a white polyimide powder. When the imidation ratio of the obtained polyimide powder (polyimide (PI-1)) was measured, it was 72%. NMP and the compound (ba) as a specific solvent (B) are added to and dissolved in this powder. The solvent composition is NMP: compound (ba) = 50: 50 (weight ratio), and the solid content concentration is 4.5% by weight. %, A liquid crystal aligning agent (S9A) was prepared.

[Reference Comparative Examples 1A to 9A]
Regarding the solvent composition of the liquid crystal aligning agent, a polymer was synthesized and the liquid crystal aligning agent was prepared in the same manner as in Reference Examples 1A to 9A except that butyl cellosolve (BC) was used instead of the specific solvent (B) as the second solvent. After preparing, liquid crystal aligning agents (R1A) to (R9A) were obtained. Reference Comparative Example XA (X is an integer of 1 to 9) is an example corresponding to Reference Example XA. That is, in Reference Comparative Example XA, the same polymer as Reference Example XA was synthesized, and a liquid crystal aligning agent was prepared in the same manner as Reference Example XA except that butyl cellosolve was used instead of the specific solvent (B).

[Reference Example 10A]
4.50 g (0.018 mol) of bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic acid 2: 4,6: 8-dianhydride (BODA) as tetracarboxylic dianhydride 2.34 g (0.0054 mol) of the compound represented by the above formula (d-4-2) as a diamine (PBCH5DAB) and 1.92 g (0.0126 mol) of 3,5-diaminobenzoic acid (35 DAB) were added to NMP26. After reacting at room temperature in 3 g, it was further reacted at 40 ° C. for 43 hours. NMP was added to 30 g of this polyamic acid solution to prepare a 6% by weight solution, to which 2.4 g of acetic anhydride and 1.8 g of pyridine were added as imidation catalysts, and reacted at room temperature for 30 minutes and 110 ° C. for 4 hours. I let it. This solution was poured into a large amount of methanol, and the obtained white precipitate was separated by filtration and dried to obtain a white polyimide powder. The imidation ratio of the obtained polyimide powder (polyimide (PI-2)) was measured to be 72%. 0.6 g of this powder was dissolved in a mixed solvent of NMP and 3-methoxy-N, N-dimethylpropionamide (D1) as the first solvent, and the compound (ba) as the specific solvent (B), and the polyimide concentration was adjusted. A 6.0% by weight solution was obtained. To this solution, 0.4 g of a 7.5% by weight NMP solution of 3-aminomethylpyridine (3-AMP) (equivalent to 0.03 g as 3-AMP) was added, and the mixture was stirred at 50 ° C. for 15 hours to obtain a liquid crystal. An orientation agent (S10A) was obtained. The liquid crystal aligning agent was prepared such that the solvent composition was NMP: D1: compound (ba) = 30: 20: 50 (weight ratio).

[Reference Example 11A]
Same as Reference Example 10A except that the amount of PBCH5DAB used for the synthesis of polyamic acid was changed to 3.90 g (0.0090 mol) and the amount of 3,5-diaminobenzoic acid was changed to 1.37 g (0.0090 mol). The operation was performed to obtain a polyamic acid solution. The same operation as in Reference Example 10A was performed using the obtained polyamic acid solution to obtain a polyimide powder. When the imidation ratio of the obtained polyimide powder (polyimide (PI-3)) was measured, it was 74%. 0.6 g of this powder was dissolved in a mixed solvent of NMP and 3-butoxy-N, N-dimethylpropionamide (D2) as the first solvent and the compound (bb) as the specific solvent (B), and the polyimide concentration was adjusted. A 6.0% by weight solution was obtained. To this solution, 0.8 g of a 7.5% by weight NMP solution of 3-aminomethylpyridine (3-AMP) (corresponding to 0.06 g as 3-AMP) was added, and the mixture was stirred at 50 ° C. for 15 hours to obtain a liquid crystal. An alignment agent (S11A) was obtained. The liquid crystal alignment agent was prepared such that the solvent composition was NMP: D2: compound (bb) = 30: 30: 40 (weight ratio).

[Reference Example 12A]
A solution containing polyamic acid (PA-1) was prepared in the same manner as in Reference Example 1A. This solution was poured into a large amount of methanol, and the obtained white precipitate was separated by filtration and dried to obtain a polyamic acid powder. This powder is dissolved in a mixed solvent of 3-methoxy-N, N-dimethylpropionamide (D1) as the first solvent and compound (bc) as the specific solvent (B), and the solvent composition is D1: compound (b -C) = 60: 40 (weight ratio), and a liquid crystal aligning agent (S12A) having a solid content concentration of 6.0% by weight was obtained.
[Reference Example 13A]
A solution containing polyamic acid (PA-2) was prepared in the same manner as in Reference Example 2A. This solution was poured into a large amount of methanol, and the obtained white precipitate was separated by filtration and dried to obtain a polyamic acid powder. This powder was dissolved in a mixed solvent of 3-butoxy-N, N-dimethylpropionamide (D2) as the first solvent and compound (bd) as the specific solvent (B), and the solvent composition was D2: compound (b) -D) = 50: 50 (weight ratio), and a liquid crystal aligning agent (S13A) having a polyamic acid concentration of 6.0% by weight was obtained.

[Reference Example 14A]
A solution containing polyamic acid (PA-3) was prepared in the same manner as in Reference Example 3A. This solution was poured into a large amount of methanol, and the obtained white precipitate was separated by filtration and dried to obtain a polyamic acid powder. This powder was dissolved in a mixed solvent of NMP and 3-methoxy-N, N-dimethylpropionamide (D1) as a first solvent and compound (be) as a specific solvent (B), and the solvent composition was NMP: D1: Compound (be) = 40: 40: 20 (weight ratio), and a liquid crystal aligning agent (S14A) having a polyamic acid concentration of 6.0% by weight was obtained.
[Reference Example 15A]
A solution containing polyamic acid (PA-4) was prepared in the same manner as in Reference Example 4A. This solution was poured into a large amount of methanol, and the obtained white precipitate was separated by filtration and dried to obtain a polyamic acid powder. This powder and N, N, N ', N'-tetraglycidyl-4,4'-diaminodiphenylmethane (E1) as an additive, NMP and 3-butoxy-N, N-dimethylpropionamide as a first solvent (D2) and the specific solvent (B) are dissolved in a mixed solvent of the compound (b-f), and the solvent composition is NMP: D2: compound (b-f) = 40: 40: 20 (weight ratio), polyamic acid A liquid crystal aligning agent (S15A) having a concentration of 6.0% by weight was obtained. The amount of the additive (E1) used was 5 parts by weight based on the polyamic acid powder.

[Reference Example 16A]
A solution containing polyamic acid (PA-5) was prepared in the same manner as in Reference Example 5A. This solution was poured into a large amount of methanol, and the obtained white precipitate was separated by filtration and dried to obtain a polyamic acid powder. This powder was dissolved in a mixed solvent of 3-methoxy-N, N-dimethylpropionamide (D1) as the first solvent and the compound (bg) as the specific solvent (B), and the solvent composition was D1: compound (b -G) = 75: 25 (weight ratio), and a liquid crystal aligning agent (S16A) having a polyamic acid concentration of 6.0% by weight was obtained.
[Reference Example 17A]
A solution containing polyamic acid (PA-6) was prepared in the same manner as in Reference Example 6A. This solution was poured into a large amount of methanol, and the obtained white precipitate was separated by filtration and dried to obtain a polyamic acid powder. This powder was dissolved in a mixed solvent of 3-butoxy-N, N-dimethylpropionamide (D2) as the first solvent and compound (bh) as the specific solvent (B), and the solvent composition was D2: compound (b) -H) = 35: 65 (weight ratio) to obtain a liquid crystal aligning agent (S17A) having a polyamic acid concentration of 6.0% by weight.

[Reference Example 18A]
A solution containing polyamic acid (PA-7) was prepared in the same manner as in Reference Example 7A. This solution was poured into a large amount of methanol, and the obtained white precipitate was separated by filtration and dried to obtain a polyamic acid powder. This powder was dissolved in a mixed solvent of NMP and γ-butyl lactone (D3) as the first solvent and compound (ba) as the specific solvent (B), and the solvent composition was NMP: D3: compound (ba) ) = 30: 30: 40 (weight ratio) and a polyamic acid concentration of 6.0% by weight to obtain a liquid crystal aligning agent (S18A).
[Reference Example 19A]
A solution containing a polyamic acid intermediate (PA-8) was prepared in the same manner as in Reference Example 8A. This solution was poured into a large amount of methanol, and the obtained white precipitate was separated by filtration and dried to obtain a polyamic acid powder. This powder was dissolved in a mixed solvent of NMP and 3-butoxy-N, N-dimethylpropionamide (D2) as the first solvent and compound (bb) as the specific solvent (B), and the solvent composition was NMP: D2: Compound (bb) = 30: 30: 40 (weight ratio), and a liquid crystal aligning agent (S19A) having a polyamic acid concentration of 6.0% by weight was obtained.
[Reference Example 20A]
A polyimide (PI-1) powder was obtained in the same manner as in Reference Example 9A. This powder is dissolved in a mixed solvent of 3-methoxy-N, N-dimethylpropionamide (D1) as the first solvent and compound (bc) as the specific solvent (B), and the solvent composition is D1: compound (b -C) = 50: 50 (weight ratio), a liquid crystal aligning agent (S20A) having a solid content concentration of 6.0% by weight was obtained.

<Evaluation of storage stability>
Each of the liquid crystal aligning agents obtained above was filtered through a 1.0 μm filter, stored at −30 ° C. for one month, returned to room temperature (25 ° C.), and checked for the presence of precipitates in the liquid crystal aligning agent. Observed. The results are shown in Tables 1 and 2 below. In Tables 1 and 2, a case where no precipitate was observed in the liquid crystal aligning agent was indicated by “○”, and a case where a precipitate was observed was indicated by “×”.

<Evaluation of printability>
Each of the liquid crystal aligning agents prepared above was filtered through a 1.0 μm filter, stored at −15 ° C. for 6 months, and then returned to room temperature (25 ° C.). Next, the liquid crystal alignment agent was applied to the transparent electrode surface of the glass substrate with a transparent electrode made of an ITO film using a liquid crystal alignment film printer (manufactured by Nissha Printing Co., Ltd.). Then, after heating (pre-baking) on a hot plate at 80 ° C. for 1 minute to remove the solvent, heating (post-baking) on a hot plate at 200 ° C. for 10 minutes to form a coating film having an average film thickness of 0.06 μm. Formed. This coating film was observed under a microscope with a magnification of 20 times to check for print unevenness and pinholes. In the evaluation, printability was good (○) when print unevenness and pinholes were hardly observed, and poor printability (x) when at least one of print unevenness and pinholes was observed. The results are shown in Tables 1 and 2 below.

The abbreviations in Table 1 and Table 2 are as follows.
(Acid dianhydride)
AN-1, 1,2,3,4-cyclobutanetetracarboxylic dianhydride AN-2; 2,3,5-tricarboxycyclopentylacetic acid dianhydride AN-3; pyromellitic dianhydride AN-4; Bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic acid 2: 4,6: 8-dianhydride (diamine)
DA-1: 1,5-bis (4-aminophenoxy) pentane DA-2: 2,4-diamino-N, N-diallylaniline DA-3: cholestanyl 3,5-diaminobenzoate 35DAB: 3,5- Diaminobenzoic acid (monoamine)
MA-1: n-dodecylamine (first solvent)
D1: 3-methoxy-N, N-dimethylpropionamide D2: 3-butoxy-N, N-dimethylpropionamide D3: γ-butyl lactone (second solvent)
BC: butyl cellosolve (additive)
3-AMP: 3-aminomethylpyridine (compound represented by the above formula (c-1-16))
E1: N, N, N ', N'-tetraglycidyl-4,4'-diaminodiphenylmethane

<Manufacture and evaluation of photo-alignment FFS type liquid crystal display device>
(1) Production of FFS-type liquid crystal display element using photo-alignment method An FFS-type liquid crystal display element 10 shown in FIG. 1 was produced. First, a glass substrate 11a having, on one side, an electrode pair in which a bottom electrode 15 having no pattern, a silicon nitride film as an insulating layer 14, and a top electrode 13 patterned in a comb shape are formed in this order; And a pair of the opposite glass substrate 11b on which the transparent electrode is not provided, and the liquid crystal aligning agent (S1A) obtained above is applied to the surface of the glass substrate 11a having the transparent electrode and one surface of the opposite glass substrate 11b by the inkjet coating method. A coating was formed. Before applying the liquid crystal aligning agent (S1A) on the substrate, the viscosity of the liquid crystal aligning agent was set to 18 cP with the solvent composition being “NMP: compound (ba) = 60: 40 (weight ratio)”. The liquid crystal aligning agent prepared and adjusted in viscosity was applied on a substrate.
Next, the coating film was pre-baked on a hot plate at 80 ° C. for 1 minute, and then heated (post-baked) at 230 ° C. for 15 minutes in an oven in which the inside of the chamber was purged with nitrogen to obtain an average film thickness of 0.1 μm. A coating was formed. FIG. 2 shows a schematic plan view of the top electrode 13 used here. FIG. 2A is a top view of the top electrode 13, and FIG. 2B is an enlarged view of a portion C1 surrounded by a broken line in FIG. 2A. In the present reference example, a substrate having a top electrode with a line width d1 of the electrode of 4 μm and a distance d2 between the electrodes of 6 μm was used. As the top electrode 13, four drive electrodes of an electrode A, an electrode B, an electrode C, and an electrode D were used. FIG. 3 shows the configuration of the drive electrodes of this liquid crystal display element. In this case, the bottom electrode 15 functions as a common electrode acting on all of the four drive electrodes, and each of the four drive electrode regions becomes a pixel region.

Next, each surface of these coating films was irradiated with polarized ultraviolet rays 300 J / m ² containing 313 nm bright lines from the normal direction of the substrate using a Hg-Xe lamp and a Glan-Taylor prism, respectively, to form a pair having a liquid crystal alignment film. Was obtained. At this time, the direction of irradiation of the polarized ultraviolet light was set to be from the normal direction of the substrate, and the direction of the polarization plane was set so that the direction of the line segment obtained by projecting the polarization plane of the polarized ultraviolet light onto the substrate was the direction of the double-headed arrow in FIG. Was subjected to a light irradiation treatment.

Then, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm is applied by screen printing to the outer periphery of the surface of the substrate having one liquid crystal alignment film, and then the liquid crystal alignment film surfaces of the pair of substrates are coated. The substrates were opposed to each other, were superposed so that the directions of projection of the polarized surfaces of polarized ultraviolet rays onto the substrate became parallel, and were pressed. The adhesive was thermally cured at 150 ° C. for 1 hour. Next, a liquid crystal “MLC-6221” manufactured by Merck was filled in the gap between the substrates from the liquid crystal injection port, and the liquid crystal injection port was sealed with an epoxy resin adhesive. Thereafter, in order to remove the flow alignment at the time of injecting the liquid crystal, it was heated to 150 ° C. and then gradually cooled to room temperature.
Next, a polarizing plate was attached to both outer surfaces of the substrate to produce an FFS type liquid crystal display device. At this time, one of the polarizing plates is attached so that the polarization direction is parallel to the direction of projection of the polarized ultraviolet light of the liquid crystal alignment film onto the substrate surface, and the other one has the polarization direction first. Was attached so as to be orthogonal to the polarization direction of the polarizing plate.
The above method was repeated to produce a total of five FFS type liquid crystal display elements, one for each of the following evaluations of liquid crystal orientation, evaluation of voltage holding ratio, evaluation of heat resistance, evaluation of bezel unevenness resistance, and evaluation of afterimage characteristics. Was provided. However, in each case, the ultraviolet irradiation under the voltage application was not performed.

(2) Evaluation of liquid crystal orientation The FFS type liquid crystal display device manufactured above was observed with a microscope at a magnification of 50 times for the presence or absence of an abnormal domain in a change in brightness when a voltage of 5 V was turned ON / OFF (applied / released). did. In the evaluation, the case where no abnormal domain was observed was regarded as “good”, and the case where an abnormal domain was observed was regarded as “poor”. In this liquid crystal display device, the liquid crystal alignment was “good”.
(3) Evaluation of voltage holding ratio With respect to the FFS type liquid crystal display element manufactured as described above, a voltage of 5 V was applied at 23 ° C. for an application time of 60 microseconds and a span of 167 milliseconds, and 167 milliseconds after the application was released. When the voltage holding ratio (VHR) was measured, the voltage holding ratio was 99.4%. As a measuring device, VHR-1 manufactured by Toyo Corporation was used.
(4) Evaluation of heat resistance The voltage holding ratio was measured in the same manner as in the above (3) evaluation of the voltage holding ratio, and the value was used as the initial VHR (VHR _BF ). Next, the liquid crystal display element after the initial VHR measurement was allowed to stand in an oven at 100 ° C. for 500 hours. Thereafter, the liquid crystal display device was allowed to stand still at room temperature and allowed to cool to room temperature. Then, the voltage holding ratio was measured in the same manner as described above, and the value was defined as VHR _AF . Further, a change rate (ΔVHR (%)) of the voltage holding ratio before and after the application of the thermal stress was determined by the following equation (EX-2).
_{△ VHR (%) = ((} VHR BF -VHR AF) ÷ VHR BF) × 100 ... (EX-2)
The heat resistance was evaluated as “heat-resistant” when the change rate ΔVHR was less than 4%, “heat-resistant” when it was 4% or more and less than 5%, and “heat-resistant” when it was 5% or more. Performed as "poor". As a result, ΔVHR was 2.9%, and the heat resistance of this liquid crystal display device was “good”.

(5) Unevenness resistance around sealant (bezel unevenness resistance)
The FFS-type liquid crystal display device manufactured as described above was stored for 30 days under the conditions of 25 ° C. and 50% RH, and then driven at an AC voltage of 5 V to observe a lighting state. The evaluation is “excellent” if no luminance difference (more black or more white) is visually recognized around the sealant, but “good” if the luminance difference disappears within 5 minutes after lighting, and “good” for 5 minutes. The case where the luminance difference disappeared within 20 minutes or more was "OK", and the case where the luminance difference was visible even after 20 minutes was "poor". As a result, in this liquid crystal display element, no luminance difference was visually recognized around the sealant, and the bezel unevenness resistance was determined to be “excellent”.
(6) Evaluation of afterimage characteristics (DC afterimage evaluation)
The photo-alignment FFS type liquid crystal display element manufactured as described above was placed in an environment of 25 ° C. and 1 atm. The bottom electrode was used as a common electrode for all of the four drive electrodes, and the potential of the bottom electrode was set to 0 V potential (ground potential). A combined voltage consisting of an AC voltage of 3.5 V and a DC voltage of 1 V was applied to the electrodes A and C for 2 hours while the electrodes B and D were short-circuited to the common electrode to apply 0 V. Immediately after 2 hours, a voltage of AC 1.5 V was applied to all of the electrodes A to D. The drive stress application region (the pixel region of the electrode A and the electrode C) and the drive stress non-application region (the pixel region of the electrode B and the electrode D) from the time when the voltage of AC 1.5V is applied to all the drive electrodes. The time required until the difference in luminance from the point no longer can be confirmed visually was measured, and this was defined as the afterimage erasing time. Note that the shorter this time is, the harder the afterimage is generated. When the afterimage elimination time was less than 30 seconds, the result was evaluated as “good”, when it was 30 seconds or more and less than 120 seconds, “OK”, and when it was 120 seconds or more, it was evaluated as “bad”. The afterimage erasing time of the liquid crystal display device was 1 second, and the afterimage characteristics were evaluated as “good”.

From the above results, all of the liquid crystal aligning agents of the reference examples using the specific solvent (B) had good storage stability when stored at low temperature, and also had good printability after storage at low temperature. On the other hand, the liquid crystal aligning agent of the reference comparative example was poor in storage stability and printability after low-temperature storage. From this, it was found that by using the specific solvent (B), it was possible to improve the storage stability while ensuring the applicability to the substrate.
[Reference Example 2]

[Reference Example 1B]
In a 50 ml four-necked flask equipped with a stirrer and a nitrogen introducing tube, 0.60 g (2.0 mmol) of 1,3-bis (4-aminophenethyl) urea (BAPU) as a diamine and p-phenylenediamine (p-PDA) were added. 1.95 g (18.0 mmol) was added, 30 g of N-methyl-2-pyrrolidone (NMP) was added, and the mixture was stirred and dissolved while supplying nitrogen. While stirring this diamine solution, 3.70 g (18.9 mmol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA) was added as tetracarboxylic dianhydride, and the solid content concentration was further increased. NMP was added to 12 wt%, and the mixture was stirred at room temperature for 4 hours under a nitrogen atmosphere to obtain a solution of polyamic acid (PA-1).
To this polyamic acid solution, NMP and a compound (2ba) represented by the following formula (2ba) as a specific solvent (B) are added, and the solvent composition is NMP: compound (2ba) = 60: 40. (Weight ratio), a liquid crystal aligning agent (S1B) was prepared so that the polyamic acid concentration was 6.0% by weight.

[Reference Example 2B]
19.2 g (0.098 mol) of CBDA as a tetracarboxylic dianhydride and 24.2 g (0.1 mol) of 1,5-bis (4-aminophenoxy) pentane as a diamine were dissolved in 343.5 g of NMP. Allowed to react for hours. The polymerization reaction proceeded easily and uniformly, and polyamic acid (PA-2) was obtained. NMP and the compound (2ba) as a specific solvent (B) are added to the NMP solution of the polyamic acid (PA-2), and the solvent composition is NMP: compound (2ba) = 50: 50 (weight ratio). A liquid crystal aligning agent (S2B) was prepared so that the polyamic acid concentration was 6.0% by weight.

[Reference Example 3B]
22.42 g (0.1 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as tetracarboxylic dianhydride and 18.73 g of 4,4′-diaminodiphenylamine (4,4 ′ DADPA) as diamine 0.094 mol) was mixed in 345.1 g of NMP and reacted at room temperature for 5 hours. The polymerization reaction proceeded easily and uniformly, and polyamic acid (PA-3) was obtained. NMP and the compound (2ba) as a specific solvent (B) are added to the NMP solution of the polyamic acid (PA-3), and the solvent composition is NMP: compound (2ba) = 80: 20 (weight ratio). A liquid crystal aligning agent (S3B) was prepared such that the polyamic acid concentration was 6.0% by weight.

[Reference Example 4B]
As a diamine, 6.5 g (0.06 mol) of p-PDA and 4- (4-trans-n-heptylcyclohexyl) phenoxy) -1,3-diaminobenzene (PCH7DAB, represented by the above formula (d-4-3)) 15.22 g (0.04 mol) of NMP was dissolved in 165 g of NMP, and 19.41 g (0.099 mol) of CBDA as tetracarboxylic dianhydride was added thereto, and reacted at room temperature for 24 hours to obtain polyamic acid (PA). -4) was obtained. The weight average molecular weight (Mw) of the obtained polyamic acid (PA-4) was 40,000. To 30 g of this solution, NMP, diethylene glycol diethyl ether (DEDG) and the compound (2ba) as a specific solvent (B) were added, and the solvent composition was NMP: DEDG: compound (2ba) = 80: 10: 10 (weight) Ratio) and a liquid crystal aligning agent (S4B) having a concentration of 4.5% by weight.

[Reference Example 5B]
1.46 g (13.5 mmol) of p-PDA as a diamine and 0.78 g (1.50 mmol) of cholestanyl 3,5-diaminobenzoate (DA-3) were mixed in 20.0 g of NMP, and tetracarboxylic dianhydride was obtained. As a product, 2.85 g (14.5 mmol) of CBDA was added, 24.7 g of NMP was added, and the mixture was reacted at 25 ° C. for 5 hours to obtain a solution containing polyamic acid (PA-5). Next, NMP and the compound (2ba) as a specific solvent (B) were added to 40.0 g of the obtained polyamic acid solution, and the solvent composition was NMP: compound (2ba) = 75: 25 (weight ratio). A liquid crystal aligning agent (S5B) was prepared so that the polyamic acid concentration was 4.0% by weight.

[Reference Example 6B]
2.58 g (13.1 mmol) of CBDA as a tetracarboxylic dianhydride and 5.0 g (13.1 mmol) of PCH7DAB as a diamine are dissolved in 43 g of NMP, and the mixture is stirred and reacted at 20 ° C. for 4 hours to obtain a polyamic acid (PA-6). ) Was obtained. Next, NMP and the compound (2ba) as the specific solvent (B) are added to the obtained NMP solution of polyamic acid (PA-6), and the solvent composition is NMP: compound (2ba) = 35: 65. (Weight ratio) A liquid crystal aligning agent (S6B) was prepared so that the solid content concentration was 3.0% by weight.

[Reference Example 7B]
8.724 g (0.04 mol) of pyromellitic dianhydride (PMDA) as tetracarboxylic dianhydride, 2.877 g (0.0266 mol) of p-PDA as diamine, and 4.567 g (0.012 mol) of PCH7DAB in NMP91 The reaction was performed at room temperature for 3 hours in 0.6 g to prepare a solution containing polyamic acid (PA-7). To 25 g of this polyamic acid solution, NMP and a compound represented by the following formula (2bb) as a specific solvent (B) (hereinafter, referred to as "compound (2bb)") were added, and the solvent composition was NMP: The liquid crystal aligning agent (S7B) was prepared such that the compound (2bb) = 60: 40 (weight ratio) and the solid content concentration was 5.0% by weight.

[Reference Example 8B]
14.64 g (0.072 mol) of 2,4-diamino-N, N-diallylaniline as a diamine, 2.96 g (0.016 mol) of n-dodecylamine as a monoamine, and 15.69 g of CBDA as a tetracarboxylic dianhydride (0.08 mol) was reacted in 300 g of NMP at room temperature for 4 hours to prepare a solution containing a polyamic acid intermediate (PA-8). NMP and the compound (2ba) as a specific solvent (B) are added to the NMP solution of the polyamic acid intermediate, and the solvent composition is NMP: compound (2ba) = 60: 40 (weight ratio), solid content A liquid crystal aligning agent (S8B) having a concentration of 6.0% by weight was prepared.

[Reference Example 9B]
4.50 g (0.018 mol) of bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic acid 2: 4,6: 8-dianhydride (BODA) as tetracarboxylic dianhydride After reacting 0.68 g (0.0018 mol) of PCH7DAB and 1.75 g (0.0162 mol) of p-PDA as a diamine in 39.3 g of NMP at room temperature, the mixture was further reacted at 40 ° C. for 43 hours. NMP was added to 42 g of this polyamic acid solution to prepare a 1% by weight solution, and 4.18 g of acetic anhydride and 6.48 g of pyridine were added as imidation catalysts, and the mixture was reacted at room temperature for 30 minutes and at 120 ° C. for 2 hours. I let it. This solution was poured into a large amount of methanol, and the obtained white precipitate was separated by filtration and dried to obtain a white polyimide powder. When the imidation ratio of the obtained polyimide powder (polyimide (PI-1)) was measured, it was 72%. NMP and the compound (2ba) as a specific solvent (B) are added to and dissolved in this powder. The solvent composition is NMP: compound (2ba) = 50: 50 (weight ratio), and the solid content concentration is 4.5% by weight. %, A liquid crystal aligning agent (S9B) was prepared.

[Reference Comparative Examples 1B, 3B to 9B]
Regarding the solvent composition of the liquid crystal aligning agent, except that butyl cellosolve (BC) was used instead of the specific solvent (B) as the second solvent, a polymer was synthesized and the liquid crystal alignment was performed in the same manner as in Reference Examples 1B, 3B to 9B. A liquid crystal aligning agent (R1B) and (R3B) to (R9B) were obtained, respectively.
[Reference Comparative Example 2B]
Regarding the solvent composition of the liquid crystal aligning agent, a polymer was synthesized and a liquid crystal aligning agent was prepared in the same manner as in Reference Example 2B, except that ethylene glycol dimethyl ether was used instead of the specific solvent (B) as the second solvent. A liquid crystal aligning agent (R2B) was obtained.
Note that Reference Comparative Example XB (X is an integer of 1 to 9) is an example corresponding to Reference Example XB. That is, in Reference Comparative Example XB, the same polymer as Reference Example XB was synthesized, and a liquid crystal alignment agent was prepared in the same manner as Reference Example XB except that butyl cellosolve or ethylene glycol dimethyl ether was used instead of the specific solvent (B). .

[Reference Example 10B]
4.50 g (0.018 mol) of bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic acid 2: 4,6: 8-dianhydride (BODA) as tetracarboxylic dianhydride 2.34 g (0.0054 mol) of the compound represented by the above formula (d-4-2) as a diamine (PBCH5DAB) and 1.92 g (0.0126 mol) of 3,5-diaminobenzoic acid (35 DAB) were added to NMP26. After reacting at room temperature in 3 g, it was further reacted at 40 ° C. for 43 hours. NMP was added to 30 g of this polyamic acid solution to prepare a 6% by weight solution, to which 2.4 g of acetic anhydride and 1.8 g of pyridine were added as imidation catalysts, and reacted at room temperature for 30 minutes and 110 ° C. for 4 hours. I let it. This solution was poured into a large amount of methanol, and the obtained white precipitate was separated by filtration and dried to obtain a white polyimide powder. The imidation ratio of the obtained polyimide powder (polyimide (PI-2)) was measured to be 72%. 0.6 g of this powder was dissolved in a mixed solvent of NMP and 3-methoxy-N, N-dimethylpropionamide (D1) as the first solvent, and the compound (2ba) as the specific solvent (B), and the polyimide concentration was dissolved. A 6.0% by weight solution was obtained. To this solution, 0.4 g of a 7.5% by weight NMP solution of 3-aminomethylpyridine (3-AMP) (equivalent to 0.03 g as 3-AMP) was added, and the mixture was stirred at 50 ° C. for 15 hours to obtain a liquid crystal. An alignment agent (S10B) was obtained. The liquid crystal alignment agent was prepared such that the solvent composition was NMP: D1: compound (2ba) = 30: 20: 50 (weight ratio).

[Reference Example 11B]
Same as Reference Example 10B except that the amount of PBCH5DAB used for the synthesis of polyamic acid was changed to 3.90 g (0.0090 mol) and the amount of 3,5-diaminobenzoic acid was changed to 1.37 g (0.0090 mol). The operation was performed to obtain a polyamic acid solution. The same operation as in Reference Example 10B was performed using the obtained polyamic acid solution to obtain a polyimide powder. When the imidation ratio of the obtained polyimide powder (polyimide (PI-3)) was measured, it was 74%. 0.6 g of this powder was dissolved in a mixed solvent of NMP and 3-butoxy-N, N-dimethylpropionamide (D2) as the first solvent and the compound (2bb) as the specific solvent (B), and the polyimide concentration was dissolved. A 6.0% by weight solution was obtained. To this solution, 0.8 g of a 7.5% by weight NMP solution of 3-aminomethylpyridine (3-AMP) (corresponding to 0.06 g as 3-AMP) was added, and the mixture was stirred at 50 ° C. for 15 hours to obtain a liquid crystal. An alignment agent (S11B) was obtained. The liquid crystal aligning agent was prepared such that the solvent composition was NMP: D2: compound (2bb) = 30: 30: 40 (weight ratio).

[Reference Example 12B]
A solution containing polyamic acid (PA-1) was prepared in the same manner as in Reference Example 1A. This solution was poured into a large amount of methanol, and the obtained white precipitate was separated by filtration and dried to obtain a polyamic acid powder. This powder was dissolved in a mixed solvent of 3-methoxy-N, N-dimethylpropionamide (D1) as a first solvent and compound (2bb) as a specific solvent (B), and the solvent composition was D1: compound (2b -B) = 60: 40 (weight ratio), a liquid crystal aligning agent (S12B) having a solid content concentration of 6.0% by weight was obtained.
[Reference Example 13B]
A solution containing polyamic acid (PA-2) was prepared in the same manner as in Reference Example 2B. This solution was poured into a large amount of methanol, and the obtained white precipitate was separated by filtration and dried to obtain a polyamic acid powder. This powder was dissolved in a mixed solvent of 3-butoxy-N, N-dimethylpropionamide (D2) as the first solvent and compound (2ba) as the specific solvent (B), and the solvent composition was D2: compound (2b -A) = 50: 50 (weight ratio), a liquid crystal aligning agent (S13B) having a polyamic acid concentration of 6.0% by weight was obtained.

[Reference Example 14B]
A solution containing polyamic acid (PA-3) was prepared in the same manner as in Reference Example 3B. This solution was poured into a large amount of methanol, and the obtained white precipitate was separated by filtration and dried to obtain a polyamic acid powder. This powder was dissolved in a mixed solvent of NMP and 3-methoxy-N, N-dimethylpropionamide (D1) as the first solvent and the compound (2ba) as the specific solvent (B), and the solvent composition was NMP: D1: Compound (2ba) = 40: 40: 20 (weight ratio), and a liquid crystal aligning agent (S14B) having a polyamic acid concentration of 6.0% by weight was obtained.
[Reference Example 15B]
A solution containing polyamic acid (PA-4) was prepared in the same manner as in Reference Example 4B. This solution was poured into a large amount of methanol, and the obtained white precipitate was separated by filtration and dried to obtain a polyamic acid powder. This powder and N, N, N ', N'-tetraglycidyl-4,4'-diaminodiphenylmethane (E1) as an additive, NMP and 3-butoxy-N, N-dimethylpropionamide as a first solvent (D2) and the specific solvent (B) are dissolved in a mixed solvent of the compound (2ba), and the solvent composition is NMP: D2: compound (2ba) = 40: 40: 20 (weight ratio), polyamic acid A liquid crystal aligning agent (S15B) having a concentration of 6.0% by weight was obtained. The amount of the additive (E1) used was 5 parts by weight based on the polyamic acid powder.

[Reference Example 16B]
A solution containing polyamic acid (PA-5) was prepared in the same manner as in Reference Example 5B. This solution was poured into a large amount of methanol, and the obtained white precipitate was separated by filtration and dried to obtain a polyamic acid powder. This powder was dissolved in a mixed solvent of 3-methoxy-N, N-dimethylpropionamide (D1) as the first solvent and compound (2ba) as the specific solvent (B), and the solvent composition was D1: compound (2b -A) = 75: 25 (weight ratio), and a liquid crystal aligning agent (S16B) having a polyamic acid concentration of 6.0% by weight was obtained.
[Reference Example 17B]
A solution containing polyamic acid (PA-6) was prepared in the same manner as in Reference Example 6B. This solution was poured into a large amount of methanol, and the obtained white precipitate was separated by filtration and dried to obtain a polyamic acid powder. This powder was dissolved in a mixed solvent of 3-butoxy-N, N-dimethylpropionamide (D2) as the first solvent and compound (2ba) as the specific solvent (B), and the solvent composition was D2: compound (2b -A) = 35: 65 (weight ratio), and a liquid crystal aligning agent (S17B) having a polyamic acid concentration of 6.0% by weight was obtained.

[Reference Example 18B]
A solution containing polyamic acid (PA-7) was prepared in the same manner as in Reference Example 7B. This solution was poured into a large amount of methanol, and the obtained white precipitate was separated by filtration and dried to obtain a polyamic acid powder. This powder was dissolved in a mixed solvent of NMP and γ-butyl lactone (D3) as the first solvent and compound (2ba) as the specific solvent (B), and the solvent composition was NMP: D3: compound (2ba). ) = 30: 30: 40 (weight ratio), and a liquid crystal aligning agent (S18B) having a polyamic acid concentration of 6.0% by weight was obtained.
[Reference Example 19B]
A solution containing a polyamic acid intermediate (PA-8) was prepared in the same manner as in Reference Example 8B. This solution was poured into a large amount of methanol, and the obtained white precipitate was separated by filtration and dried to obtain a polyamic acid powder. This powder was dissolved in a mixed solvent of NMP and 3-butoxy-N, N-dimethylpropionamide (D2) as a first solvent and compound (2bb) as a specific solvent (B), and the solvent composition was NMP: D2: Compound (2b-b) = 30: 30: 40 (weight ratio) and a liquid crystal aligning agent (S19B) having a polyamic acid concentration of 6.0% by weight were obtained.
[Reference Example 20B]
A powder of polyimide (PI-1) was obtained in the same manner as in Reference Example 9B. This powder was dissolved in a mixed solvent of 3-methoxy-N, N-dimethylpropionamide (D1) as the first solvent and compound (2ba) as the specific solvent (B), and the solvent composition was D1: compound (2b -A) = 50: 50 (weight ratio), and a liquid crystal aligning agent (S20B) having a solid content of 6.0% by weight was obtained.

<Evaluation of storage stability>
Each of the liquid crystal aligning agents obtained above was filtered through a 1.0 μm filter, stored at −30 ° C. for one month, returned to room temperature (25 ° C.), and checked for the presence of precipitates in the liquid crystal aligning agent. Observed. The results are shown in Tables 3 and 4 below. In Tables 3 and 4, a case where no precipitate was observed in the liquid crystal aligning agent was indicated by “○”, and a case where a precipitate was observed was indicated by “×”.

<Evaluation of printability>
Each of the liquid crystal aligning agents prepared above was filtered through a 1.0 μm filter, stored at −15 ° C. for 6 months, and then returned to room temperature (25 ° C.). Next, the liquid crystal alignment agent was applied to the transparent electrode surface of the glass substrate with a transparent electrode made of an ITO film using a liquid crystal alignment film printer (manufactured by Nissha Printing Co., Ltd.). Then, after heating (pre-baking) on a hot plate at 80 ° C. for 1 minute to remove the solvent, heating (post-baking) on a hot plate at 200 ° C. for 10 minutes to form a coating film having an average film thickness of 0.06 μm. Formed. This coating film was observed under a microscope with a magnification of 20 times to check for print unevenness and pinholes. In the evaluation, printability was good (○) when print unevenness and pinholes were hardly observed, and poor printability (x) when at least one of print unevenness and pinholes was observed. The results are shown in Tables 3 and 4 below.

The abbreviations in Tables 3 and 4 are as follows.
(Acid dianhydride)
AN-1, 1,2,3,4-cyclobutanetetracarboxylic dianhydride AN-2; 2,3,5-tricarboxycyclopentylacetic acid dianhydride AN-3; pyromellitic dianhydride AN-4; Bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic acid 2: 4,6: 8-dianhydride (diamine)
DA-1: 1,5-bis (4-aminophenoxy) pentane DA-2: 2,4-diamino-N, N-diallylaniline DA-3: cholestanyl 3,5-diaminobenzoate 35DAB: 3,5- Diaminobenzoic acid (monoamine)
MA-1: n-dodecylamine (first solvent)
D1: 3-methoxy-N, N-dimethylpropionamide D2: 3-butoxy-N, N-dimethylpropionamide D3: γ-butyl lactone (second solvent)
D4: ethylene glycol dimethyl ether DEDG: diethylene glycol diethyl ether BC: butyl cellosolve (additive)
3-AMP: 3-aminomethylpyridine (compound represented by the above formula (c-1-16))
E1: N, N, N ', N'-tetraglycidyl-4,4'-diaminodiphenylmethane

<Manufacture and evaluation of photo-alignment FFS type liquid crystal display device>
(1) Production of FFS-type liquid crystal display element using photo-alignment method An FFS-type liquid crystal display element 10 shown in FIG. 1 was produced. First, a glass substrate 11a having, on one side, an electrode pair in which a bottom electrode 15 having no pattern, a silicon nitride film as an insulating layer 14, and a top electrode 13 patterned in a comb shape are formed in this order; And a pair of the opposite glass substrate 11b not provided with the liquid crystal aligning agent (S1B) obtained above on the surface of the glass substrate 11a having the transparent electrode and one surface of the opposite glass substrate 11b by an inkjet coating method. A coating was formed. Before applying the liquid crystal aligning agent (S1B) on the substrate, the liquid crystal aligning agent (S1B) was prepared so that the viscosity was 18 cP with the solvent composition being “NMP: (2ba) = 60: 40 (weight ratio)”. Then, the liquid crystal aligning agent whose viscosity was adjusted was applied on the substrate.
Next, the coating film was pre-baked on a hot plate at 80 ° C. for 1 minute, and then heated (post-baked) at 230 ° C. for 15 minutes in an oven in which the inside of the chamber was purged with nitrogen to obtain an average thickness of 1,000 °. A coating was formed. FIG. 2 shows a schematic plan view of the top electrode 13 used here. FIG. 2A is a top view of the top electrode 13, and FIG. 2B is an enlarged view of a portion C1 surrounded by a broken line in FIG. 2A. In the present reference example, a substrate having a top electrode with a line width d1 of the electrode of 4 μm and a distance d2 between the electrodes of 6 μm was used. Further, as the top electrode 13, four drive electrodes of an electrode A, an electrode B, an electrode C, and an electrode D were used. FIG. 3 shows the configuration of the drive electrodes of this liquid crystal display element. In this case, the bottom electrode 15 functions as a common electrode acting on all of the four drive electrodes, and each of the four drive electrode regions becomes a pixel region.

Next, each surface of these coating films was irradiated with polarized ultraviolet rays 300 J / m ² containing 313 nm bright lines from the normal direction of the substrate using a Hg-Xe lamp and a Glan-Taylor prism, respectively, to form a pair having a liquid crystal alignment film. Was obtained. At this time, the direction of irradiation of the polarized ultraviolet light was set to be from the normal direction of the substrate, and the direction of the polarization plane was set so that the direction of the line segment obtained by projecting the polarization plane of the polarized ultraviolet light onto the substrate was the direction of the double-headed arrow in FIG. Was subjected to a light irradiation treatment.

Then, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm is applied by screen printing to the outer periphery of the surface of the substrate having one liquid crystal alignment film, and then the liquid crystal alignment film surfaces of the pair of substrates are coated. The substrates were opposed to each other, were superposed so that the directions of projection of the polarized surfaces of polarized ultraviolet rays onto the substrate became parallel, and were pressed. The adhesive was thermally cured at 150 ° C. for 1 hour. Next, a liquid crystal “MLC-6221” manufactured by Merck was filled in the gap between the substrates from the liquid crystal injection port, and the liquid crystal injection port was sealed with an epoxy resin adhesive. Thereafter, in order to remove the flow alignment at the time of injecting the liquid crystal, it was heated to 150 ° C. and then gradually cooled to room temperature.
Next, a polarizing plate was attached to both outer surfaces of the substrate to produce an FFS type liquid crystal display device. At this time, one of the polarizing plates is attached so that the polarization direction is parallel to the direction of projection of the polarized ultraviolet light of the liquid crystal alignment film onto the substrate surface, and the other one has the polarization direction first. Was attached so as to be orthogonal to the polarization direction of the polarizing plate.
The above method was repeated to produce a total of five FFS type liquid crystal display elements, one for each of the following evaluations of liquid crystal orientation, evaluation of voltage holding ratio, evaluation of heat resistance, evaluation of bezel unevenness resistance, and evaluation of afterimage characteristics. Was provided. However, in each case, the ultraviolet irradiation under the voltage application was not performed.

(2) Evaluation of liquid crystal orientation The FFS type liquid crystal display device manufactured above was observed with a microscope at a magnification of 50 times for the presence or absence of an abnormal domain in a change in brightness when a voltage of 5 V was turned ON / OFF (applied / released). did. In the evaluation, the case where no abnormal domain was observed was regarded as “good”, and the case where an abnormal domain was observed was regarded as “poor”. In this liquid crystal display device, the liquid crystal alignment was “good”.
(3) Evaluation of voltage holding ratio With respect to the FFS type liquid crystal display element manufactured as described above, a voltage of 5 V was applied at 23 ° C. for an application time of 60 microseconds and a span of 167 milliseconds, and 167 milliseconds after the application was released. When the voltage holding ratio (VHR) was measured, the voltage holding ratio was 99.4%. As a measuring device, VHR-1 manufactured by Toyo Corporation was used.
(4) Evaluation of heat resistance The voltage holding ratio was measured in the same manner as in the above (3) evaluation of the voltage holding ratio, and the value was used as the initial VHR (VHR _BF ). Next, the liquid crystal display element after the initial VHR measurement was allowed to stand in an oven at 100 ° C. for 500 hours. Thereafter, the liquid crystal display device was allowed to stand still at room temperature and allowed to cool to room temperature. Then, the voltage holding ratio was measured in the same manner as described above, and the value was defined as VHR _AF . Further, a change rate (ΔVHR (%)) of the voltage holding ratio before and after the application of the thermal stress was determined by the following equation (EX-2).
_{△ VHR (%) = ((} VHR BF -VHR AF) ÷ VHR BF) × 100 ... (EX-2)
The heat resistance was evaluated as “heat-resistant” when the change rate ΔVHR was less than 4%, “heat-resistant” when it was 4% or more and less than 5%, and “heat-resistant” when it was 5% or more. Performed as "poor". As a result, ΔVHR was 2.9%, and the heat resistance of this liquid crystal display device was “good”.

(5) Unevenness resistance around sealant (bezel unevenness resistance)
The FFS-type liquid crystal display device manufactured as described above was stored for 30 days under the conditions of 25 ° C. and 50% RH, and then driven at an AC voltage of 5 V to observe a lighting state. The evaluation is “excellent” if no luminance difference (more black or more white) is visually recognized around the sealant, but “good” if the luminance difference disappears within 5 minutes after lighting, and “good” for 5 minutes. The case where the luminance difference disappeared within 20 minutes or more was "OK", and the case where the luminance difference was visible even after 20 minutes was "poor". As a result, in this liquid crystal display element, no luminance difference was visually recognized around the sealant, and it was determined to be “excellent”.
(6) Evaluation of afterimage characteristics (DC afterimage evaluation)
The photo-alignment type liquid crystal display device produced above was placed in an environment of 25 ° C. and 1 atm. The bottom electrode was used as a common electrode for all of the four drive electrodes, and the potential of the bottom electrode was set to 0 V potential (ground potential). A combined voltage consisting of an AC voltage of 3.5 V and a DC voltage of 1 V was applied to the electrodes A and C for 2 hours while the electrodes B and D were short-circuited to the common electrode to apply 0 V. Immediately after 2 hours, a voltage of AC 1.5 V was applied to all of the electrodes A to D. The drive stress application region (the pixel region of the electrode A and the electrode C) and the drive stress non-application region (the pixel region of the electrode B and the electrode D) from the time when the voltage of AC 1.5V is applied to all the drive electrodes. The time required until the difference in luminance from the point no longer can be confirmed visually was measured, and this was defined as the afterimage erasing time. Note that the shorter this time is, the harder the afterimage is generated. When the afterimage elimination time was less than 30 seconds, the result was evaluated as “good”, when it was 30 seconds or more and less than 120 seconds, “OK”, and when it was 120 seconds or more, it was evaluated as “bad”. The afterimage erasing time of the liquid crystal display device was 1 second, and the afterimage characteristics were evaluated as “good”.

As shown in Tables 3 and 4, each of the liquid crystal aligning agents of Reference Examples using the specific solvent (B) has good storage stability when stored at low temperature, and also has good printability after storage at low temperature. It was good. On the other hand, the liquid crystal aligning agent of the reference comparative example was poor in storage stability and printability after low-temperature storage. From this, it was found that by using the specific solvent (B), it was possible to improve the storage stability while ensuring the applicability to the substrate.
[Example]

<Synthesis of polyimide>
[Synthesis Example 1: Synthesis of polyimide (PI-1C)]
22.4 g (0.1 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride (TCA) as tetracarboxylic dianhydride and 8.6 g (0.08 mol) of p-phenylenediamine (PDA) as diamine ) And cholestanyl 3,5-diaminobenzoate (HCDA) (10.5 g, 0.02 mol) were dissolved in N-methyl-2-pyrrolidone (NMP) (166 g) and reacted at 60 ° C. for 6 hours to obtain polyamic acid. Was obtained. A small amount of the obtained polyamic acid solution was fractionated, N-methyl-2-pyrrolidone was added thereto, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 90 mPa · s.

  Next, NMP was added to the obtained polyamic acid solution to make a solution having a polyamic acid concentration of 7% by weight, 11.9 g of pyridine and 15.3 g of acetic anhydride were added, and a dehydration ring closure reaction was performed at 110 ° C. for 4 hours. . After the dehydration ring-closing reaction, the solvent in the system was solvent-replaced with fresh NMP (the pyridine and acetic anhydride used in the dehydration ring-closing reaction were removed from the system by this operation; the same applies hereinafter), resulting in an imidization ratio of about 68. % Polyimide (PI-1C) was obtained. A small amount of the obtained polyimide solution was fractionated, NMP was added thereto, and the solution viscosity measured as a solution having a polyimide concentration of 10% by weight was 45 mPa · s.

[Synthesis Example 2: Synthesis of polyimide (PI-2C)]
22.5 g (0.1 mol) of TCA as tetracarboxylic dianhydride, 7.6 g (0.07 mol) of PDA as diamine, 5.2 g (0.01 mol) of HCDA and 4,4′-diaminodiphenylmethane (DDM) 4 0.0g (0.02 mol) was dissolved in 157g of 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 fractionated, NMP was added thereto, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 110 mPa · s.

  Next, NMP was added to the obtained polyamic acid solution to make a solution having a polyamic acid concentration of 7% by weight, 16.6 g of pyridine and 21.4 g of acetic anhydride were added, and a 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 NMP to obtain a solution containing 26% by weight of polyimide (PI-2C) having an imidization ratio of about 82%. A small amount of the obtained polyimide solution was fractionated, NMP was added thereto, and the solution viscosity measured as a solution having a polyimide concentration of 10% by weight was 62 mPa · s.

[Synthesis Example 3: Synthesis of polyimide (PI-3C)]
As a tetracarboxylic dianhydride, 2,4,6,8-tetracarboxybicyclo [3.3.0] octane-2: 4,6: 8-dianhydride (BODA) 24.9 g (0.10 mol) 8.6 g (0.08 mol) of PDA and 10.4 g (0.02 mol) of HCDA were dissolved in 176 g of 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 taken out, NMP was added thereto, and the solution viscosity measured as a solution having a polyamic acid concentration of 10% by weight was 103 mPa · s.

  Next, NMP was added to the obtained polyamic acid solution to make a solution having a polyamic acid concentration of 7% by weight, 11.9 g of pyridine and 15.3 g of acetic anhydride were added, and a 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 NMP to obtain a solution containing 26% by weight of polyimide (PI-3C) having an imidization ratio of about 71%. A small amount of the obtained polyimide solution was fractionated, NMP was added thereto, and the solution viscosity measured as a solution having a polyimide concentration of 10% by weight was 57 mPa · s.

<Preparation of liquid crystal alignment agent>
[Example 1C]
In a solution containing 100 parts by weight of the synthesized polyimide (PI-1C), as a solvent, NMP, ethylene glycol mono-n-butyl ether (butyl cellosolve, BC) and a compound represented by the following formula (b1-1) (hereinafter, referred to as “ Compound (b1-1) ") was added to obtain a solution having a solvent composition of NMP: BC: compound (b1-1) = 30: 50: 20 (weight ratio) and a solid concentration of 6.5% by weight. This solution was filtered using a filter having a pore size of 1 μm to prepare a liquid crystal aligning agent (S-1).

[Examples 2C to 18C, Comparative Examples 1C to 4C]
Liquid crystal aligning agents (S-2) to (S-18), (SR-1) to (C-2) in the same manner as in Example 1C, except that the polyimide and the solvent composition used were changed as described in Table 5 below. (SR-4) was prepared.

<Evaluation of printability>
Each of the liquid crystal aligning agents prepared above was evaluated for printability. The evaluation was performed as follows. First, for each of the prepared liquid crystal aligning agents, the amount of the liquid crystal aligning agent dropped onto the anilox roll was measured using a liquid crystal alignment film printing machine (manufactured by Nissha Printing Co., Ltd., Angstromer type “S40L-532”). Was applied to the transparent electrode surface of a glass substrate with a transparent electrode made of an ITO film under the condition of 20 drops (about 0.2 g) in a reciprocating manner. Coating on the substrate was performed 20 times at one minute intervals using a new substrate.
Subsequently, the liquid crystal aligning agent was dispensed (one way) on the anilox roll at one-minute intervals, and each time the operation of bringing the anilox roll and the printing plate into contact (hereinafter, referred to as idle operation) was performed a total of 10 times (during this time, Printing on a glass substrate is not performed). The idle operation is not performed in the normal manufacturing process of the liquid crystal display element, but is an operation performed for intentionally performing printing of the liquid crystal alignment agent on the substrate under severe conditions.

After ten idle operations, actual printing was performed using a glass substrate. In this printing, after idling, five substrates were loaded at intervals of 30 seconds, each substrate coated with a liquid crystal alignment agent was heated (prebaked) at 80 ° C. for 1 minute to remove the solvent, and then removed at 200 ° C. By heating (post-baking) for 10 minutes, a coating film having a thickness of about 80 nm was formed. The printability was evaluated by observing the pattern edge portion (outer peripheral portion of the print pattern) of this coating film with a microscope having a magnification of 20 times. The evaluation was excellent (○) when no precipitate (presumed to be polyimide) was observed from the first printing after idling, and the precipitate was observed at the first printing after idling. The case where the precipitate disappeared during the printing five times was evaluated as good (△), and the case where the precipitate was observed even after the printing was repeated five times was evaluated as poor (x). The evaluation results are shown in Table 5 below. Experiments have shown that a liquid crystal aligning agent having good printability improves (disappears) the precipitates during continuous loading of the substrate.
The printability of the liquid crystal aligning agent was evaluated by performing the same operation as described above except that the number of idle operations was changed to 15, 20, and 25 times, respectively. The evaluation results are shown in Table 5 below.

<Evaluation of drying level on film surface>
The drying level of the film surface was evaluated for the coating film after the prebaking in the above “Evaluation of printability”. The evaluation was made as good (○) when the sticky feeling did not remain when the film surface was touched by hand, and as poor (x) when the sticky feeling remained. The evaluation results are shown in Table 5 below. In this case, the evaluation was performed using the substrate of the main printing performed after ten times of idling.

In addition, the symbol of the solvent composition in Table 5 has the following meaning, respectively.
a: N-methyl-2-pyrrolidone (NMP)
b: ethylene glycol mono-n-butyl ether (BC)
d: Compound (b1-1)
e: Compound represented by the following formula (b2-1) f: Compound represented by the following formula (b2-2) g: N-vinyl-2-pyrrolidone h: N-cyclohexyl-2-pyrrolidone i: N-octyl-2-pyrrolidone

  Regarding the printability, no precipitate was observed in any of the liquid crystal aligning agents of the examples from the first time of the main printing after ten idle rotations. This was the same after 15 idle runs. When the number of idle operations was increased to 20 or 25 times, some precipitates were observed in the first printing, but the deposits were not observed until the end of the fifth printing. Disappeared. From these facts, it was found that the liquid crystal aligning agents of the examples hardly generate precipitates during printing and have good printability.

  Reference Signs List 10: liquid crystal display element, 11a, 11b: glass substrate, 12: liquid crystal alignment film, 13: top electrode, 14: insulating layer, 15: bottom electrode, 16: liquid crystal layer

Claims (8)

A liquid crystal aligning agent containing at least one polymer (A) selected from the group consisting of polyamic acid, polyimide, and polyamic acid ester, and a solvent,
A liquid crystal aligning agent, wherein the solvent contains at least one selected from the group consisting of a compound represented by the following formula (b1) and a compound represented by the following formula (b2).

(In the formula (b1), R is an alkyl group having 1 to 3 carbon atoms, n is an integer of 0 to 2. In the formula (b2), m is an integer of 0 to 2.) The polymer (A) includes a polymer having a partial structure derived from at least one diamine selected from the group consisting of compounds represented by the following formulas (d-1) to (d-5). The liquid crystal aligning agent according to claim 1 .

(In the formula (d-1), X ¹ and X ² are each independently a single bond, —O—, —S—, —OCO— or —COO—, and Y ¹ is an oxygen atom or a sulfur atom. R ¹¹ and R ¹² are each independently an alkanediyl group having 1 to 3 carbon atoms, R ⁸ and R ⁹ are each independently a hydrogen atom or a protecting group, and n1 is 0 or 1. , and the is n2 and n3, the case of n1 = 0, an integer satisfying n2 + n3 = 2, when the n1 = 1, in a n2 = n3 = 1. formula (d-2), ^{X 3} is a single A bond, —O— or —S—, and m1 is an integer of 0 to 3. m2 is an integer of 1 to 12 when m1 = 0, and m2 when m1 is an integer of 1 to 3. = 2 In the formula (d-3), R ³ is a monovalent hydrocarbon group having 1 to 12 carbon atoms, and R ⁴ is a hydrogen atom or a carbon atom. R ⁵ and R ⁶ are each independently a hydrogen atom or a methyl group, and in formula (d-4), X ⁴ and X ⁵ are each independently a hydrogen atom or a methyl group. Is a single bond, —O—, —COO— or —OCO—, R ⁷ is an alkanediyl group having 1 to 3 carbon atoms, and A ⁴ is a single bond or an alkanediyl 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 k is 0 or 1, provided that a and b are 0 at the same time. In the formula (d-5), A ⁵ represents a single bond, an alkanediyl group having 1 to 12 carbon atoms or a fluoroalkanediyl group having 1 to 6 carbon atoms, and A ⁶ represents —O— or —COO. -, - OCO -, - NHCO -, - CONH- or -CO- indicates a monovalent organic ^{a 7} is having a steroid skeleton Are shown.) The content of at least one compound selected from the group consisting of the compound represented by the formula (b1) and the compound represented by the following formula (b2) is 1 to 70% by weight based on the total amount of the solvent. the liquid crystal aligning agent according to claim 1 or 2. The polymer (A) is a compound represented by the following formula (t-1), 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride The liquid crystal aligning agent according to any one of claims 1 to 3 , which is a polymer having a partial structure derived from at least one tetracarboxylic dianhydride selected from the group consisting of pyromellitic dianhydride and pyromellitic dianhydride. .

(In the formula (t-1), X ⁷ , X ⁸ , X ⁹ and X ¹⁰ are each independently a single bond or a methylene group, and j is an integer of 1 to 3.) An amine compound (C) having one primary amino group and a nitrogen-containing aromatic heterocycle in the molecule, and wherein the primary amino group is bonded to a chain hydrocarbon group or an alicyclic hydrocarbon group. The liquid crystal aligning agent according to any one of claims 1 to 4 , further comprising: The liquid crystal aligning agent according to claim 5 , wherein the amine compound (C) is a compound represented by the following formula (c-1).

(In the formula (c-1), A ¹ is a divalent organic group having a chain hydrocarbon group or an alicyclic hydrocarbon group, and A ² is a nitrogen-containing aromatic heterocycle. primary amino groups in the formula are attached to a linear hydrocarbon group or an alicyclic hydrocarbon group a ¹ has.) A liquid crystal alignment film formed using the liquid crystal alignment agent according to any one of claims 1 to 6 . A liquid crystal display device comprising the liquid crystal alignment film according to claim 7 .

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