JP6702373B2 - Liquid crystal aligning agent - Google Patents

Description

The present invention relates to a liquid crystal aligning agent, details storage stability about the good liquid crystal alignment agent.

Conventionally, as a liquid crystal display element, various driving methods having different electrode structures and different physical properties of liquid crystal molecules to be used have been developed. For example, TN type, STN type, vertical alignment type (VA type), in-plane Various liquid crystal display elements such as a switching type (IPS type), an FFS type, and an optical compensation bent type (OCB type) are known. These liquid crystal display elements 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 it has various properties such as heat resistance, mechanical strength, and affinity with liquid crystal.

In the liquid crystal aligning agent, the polymer component is dissolved in a solvent, and the liquid crystal aligning film is formed by applying the liquid crystal aligning agent to a substrate and heating. Here, as a solvent for 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, in order to improve the coatability (printability) of the liquid crystal aligning agent when the liquid crystal aligning agent is applied to the substrate, for example, butyl cellosolve, etc. Such a poor solvent having a relatively low surface tension is used together (see, for example, Patent Document 1 and Patent Document 2).

JP, 2010-97188, A JP, 2010-156934, A

The liquid crystal aligning agent is usually stored in an extremely low temperature environment (for example, at −15° C.) in order to prevent the deterioration of the polyamic acid or the polyimide from the time of manufacture to the time of shipment. However, a liquid crystal aligning agent stored at a low temperature for a long time may cause a precipitate in the solution. In addition, the once-deposited substance is difficult to be redissolved, which may cause a defect such as printing failure in the manufacturing process of the liquid crystal display element. The cause of such precipitates is not clear, but it is presumed that butyl cellosolve, which is generally used as a solvent component of the liquid crystal aligning agent, is one of the causes. Therefore, it is required to find a new organic solvent that replaces butyl cellosolve as a solvent for improving the coatability of the substrate.

The present invention has been made in view of the above problems, and it is an object of the present invention to provide a liquid crystal aligning agent having good storage stability for long-term low temperature storage and good coatability on a substrate.

The present inventors have conducted intensive studies to achieve the above-mentioned problems of the prior art, in a liquid crystal aligning agent containing a polyimide or a precursor thereof as a polymer component, a specific solvent as at least a part of the solvent component. The inventors have found that the above problems can be solved by using them, and completed the present invention. Specifically, the present invention provides the following liquid crystal aligning agent, liquid crystal aligning film and liquid crystal display device.

In the first aspect of the present invention, at least one polymer (A) selected from the group consisting of a polyamic acid obtained by reacting a tetracarboxylic dianhydride and a diamine, a polyimide and a polyamic acid ester, and a solvent , A liquid crystal aligning agent containing the compound, wherein the solvent contains a compound represented by the following formula (b-1A) as a specific solvent (B), and the polymer (A) has the following formula (d-1) ) To a compound represented by formula (d-4) (wherein X ³ in formula (d-2) is —O—) using a diamine containing at least one selected from the group consisting of: A liquid crystal aligning agent which is a polymer obtained is provided.

（式（ｂ−１Ａ）中、Ｒ^８〜Ｒ^１０は、それぞれ独立に炭素数１〜５の１価の炭化水素基である。）

(In the formula (b-1A), R ^{8 to} R ¹⁰ are each independently a monovalent hydrocarbon group having 1 to 5 carbon atoms.)

（式（ｂ−１Ｂ）中、Ｒ^８、Ｒ^９及びＲ^１１は、それぞれ独立に炭素数１〜５の１価の炭化水素基又は水素原子であり、Ｘは、ＯＨ基又はＳＨ基であり、ｎは０又は１である。）

(In the formula (b-1B), R ⁸ , R ⁹ and R ¹¹ are each independently a monovalent hydrocarbon group having 1 to 5 carbon atoms or a hydrogen atom, and X is an OH group or an SH group. , N is 0 or 1.)

（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^１及びＲ^２は、それぞれ独立に、炭素数１〜３のアルカンジイル基である。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^１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^２は−Ｏ−、−ＣＯＯ−、−ＯＣＯ−、−ＮＨＣＯ−、−ＣＯＮＨ−又は−ＣＯ−を示し、Ａ^３はステロイド骨格を有する１価の有機基を示す。）

(In 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. And R ¹ and R ² are each independently an alkanediyl group having 1 to 3 carbon atoms, n1 is 0 or 1, and n2 and n3 satisfy n2+n3=2 when n1=0. It is an integer, and in the case of n1=1, n2=n3=1 In the formula (d-2), X ³ is a single 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=2 when m1 is an integer of 1 to 3. In formula (d-3), R ³ is a carbon number. It is a monovalent hydrocarbon group of 1 to 12, R ⁴ is a hydrogen atom or a monovalent hydrocarbon group of 1 to 12 carbon atoms, and R ⁵ and R ⁶ are each independently a hydrogen atom or In the formula (d-4), X ⁴ and X ⁵ are each independently a single bond, —O—, —COO— or —OCO—, and R ⁷ has 1 to 3 carbon atoms. of an alkanediyl group, ^{a 4} is a single bond or an alkanediyl group having 1 to 3 carbon atoms .a is 0 or 1, b is an integer of 0 to 2, c is 1 to 20 It is an integer and k is 0 or 1. However, a and b are not 0 at the same time, In formula (d-5), A ¹ is a single bond, an alkanediyl group having 1 to 12 carbon atoms, or A fluoroalkanediyl group having 1 to 6 carbon atoms is shown, A ² is -O-, -COO-, -OCO-, -NHCO-, -CONH- or -CO-, and A ³ has a steroid skeleton. Indicates a valent organic group.)

When the above-mentioned specific solvent (B) is contained as the solvent component of the liquid crystal aligning agent, precipitates are unlikely to be generated in the aligning agent even when stored in a low temperature environment for a long time, and storage stability is good. is there. Further, the coating property of the liquid crystal aligning agent on the substrate is also good.

In a second aspect, the present invention contains at least one polymer (A) selected from the group consisting of polyamic acid, polyimide and polyamic acid ester, a solvent, and an additive, and the solvent is the specific solvent ( B), having one primary amino group and a nitrogen-containing aromatic heterocycle in the molecule as the additive, and the primary amino group is a chain hydrocarbon group or an alicyclic hydrocarbon. Provided is a liquid crystal aligning agent containing an amine compound (C) bonded to a group.

In a liquid crystal aligning agent containing the above polymer (A) as at least a part of the polymer component, when the above amine compound (C) is included as an additive, the liquid crystal aligning agent is stored for a long time in a low temperature environment. In that case, there may occur a problem that the amine compound (C) is precipitated in the alignment agent. In this respect, according to the liquid crystal aligning agent of the second aspect of the present invention, by including the above-mentioned specific solvent (B) as a solvent component, the liquid crystal aligning agent is contained in the aligning agent even when stored in a low temperature environment for a long period of time. Precipitates hardly occur and storage stability is good. Further, the coating property of the liquid crystal aligning agent on the substrate is also good.

The present invention provides, in a third aspect, a liquid crystal alignment film formed by the liquid crystal aligning agent according to the first aspect or the liquid crystal aligning agent according to the second side, and a liquid crystal display device including the liquid crystal aligning film. .. Since the liquid crystal aligning film of the present invention is formed by using the above liquid crystal aligning agent, the coating property (printability) is good even when the liquid crystal aligning agent is stored for a long period of time in a low temperature environment. Further, when a liquid crystal display device is manufactured using such a liquid crystal alignment film, printing defects can be reduced in the manufacturing process, and as a result, the yield of products can be improved.

The schematic block diagram of a FFS type liquid crystal cell. FIG. 3 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 a top electrode, (b) is a partial enlarged view of a top electrode. The figure which shows the drive electrode of 4 systems. FIG. 3 is a schematic plan view of a top electrode used for manufacturing a liquid crystal display element by rubbing treatment. (A) is a top view of a top electrode, (b) is a partial enlarged view of a top electrode.

The liquid crystal aligning agent according to the present invention contains, as a polymer component, at least one polymer (A) selected from the group consisting of polyamic acid, polyimide and polyamic acid ester, and the polymer (A) is used as a solvent. It is prepared as a liquid composition which is dispersed or dissolved. Hereinafter, the liquid crystal aligning agent according to the present invention will be described.

<<Polymer (A)>>
<Polyamic acid>
The polyamic acid in the present invention can be obtained by reacting a tetracarboxylic dianhydride and 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 acid dianhydride]
Examples of the tetracarboxylic acid dianhydride used for the synthesis of the polyamic acid include aliphatic tetracarboxylic acid dianhydride, alicyclic tetracarboxylic acid dianhydride, aromatic tetracarboxylic acid dianhydride, and the like. Specific examples of these are:
As the aliphatic tetracarboxylic dianhydride, for example, 1,2,3,4-butanetetracarboxylic dianhydride and the like;
Examples of the alicyclic tetracarboxylic acid dianhydride include 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 1,3,3a,4. 5,9b-Hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione, 1,3,3a,4,5,9b- Hexahydro-8-methyl-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione, 3-oxabicyclo[3.2.1]octane -2,4-dione-6-spiro-3'-(tetrahydrofuran-2',5'-dione), 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene- 1,2-dicarboxylic acid anhydride, 3,5,6-tricarboxy-2-carboxymethylnorbornane-2:3,5:6-dianhydride, 4,9-dioxatricyclo[5.3.1] .0 ^2,6] undecane -3,5,8,10- tetraone, cyclohexane tetracarboxylic acid dianhydride represented by 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
Examples of the aromatic tetracarboxylic dianhydrides include, for example, pyromellitic dianhydride; and the tetracarboxylic dianhydrides described in JP 2010-97188 A can be used. The tetracarboxylic dianhydride may 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 so on. Among the compounds represented by the above formula (t-1), from the viewpoint of stability of liquid crystal alignment, bicyclo[3.3.0]octane-2,4,6,8-tetracarboxylic dianhydride is particularly preferable. Is preferred.

Among the above-mentioned tetracarboxylic acid dianhydrides used in the synthesis of polyamic acid, compounds represented by the above formula (t-1), 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 1,2 It is preferable to use at least one compound selected from the group consisting of 3,3,4-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 synthesizing the polyamic acid. Is preferable and 20 to 100 mol% is more preferable.

[Diamine]
As the diamine used for the synthesis of the polyamic acid, the compound represented by the formula (d-1), the compound represented by the formula (d-2), the compound represented by the 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 above formula (d-1), examples of the alkanediyl group having 1 to 3 carbon atoms of R ¹ and R ² include a methylene group, an ethylene group, a propane-1,2-diyl group, and a propane-1,3-diyl group. Group, a propane-2,3-diyl group and the like. Of these, a methylene group, an ethylene group or a propane-1,3-diyl group is preferable.
X ¹ and X ² are single bonds, —O—, —S—, —OCO— or —COO—. Note that 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. It is preferably an oxygen atom.

When n1=0, the two primary amino groups of the compound represented by the formula (d-1) may be bonded to the same benzene ring, or may be bonded to two different benzene rings one by one. 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 2-position, 3-position and 4-position with respect to the other groups, and 3-position or 4-position. Is preferred, and 4-position is more preferred. When there are two primary amino groups on the benzene ring, the bonding position thereof may be, for example, 2,4-position or 2,5-position with respect to the other groups, and among them, 2,4-position is preferred. Rank 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 group in which at least one hydrogen atom on the hydrocarbon group is substituted with a fluorine atom. Or may be substituted with 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). Phenyl group, tolyl group, etc.), aralkyl group having 5 to 10 carbon atoms (benzyl group, etc.) and the like.

The "hydrocarbon group" in the present specification is meant to include a chain hydrocarbon group, an alicyclic hydrocarbon group and an aromatic hydrocarbon group. Further, the “chain hydrocarbon group” means a straight chain hydrocarbon group or a branched hydrocarbon group which does not include a cyclic structure in the main chain and is composed of only a chain structure. 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 does not need to be composed only of an alicyclic hydrocarbon structure, and some of them may have a chain structure. The “aromatic hydrocarbon group” means a hydrocarbon group containing an aromatic ring structure as a ring structure. However, the structure need not be composed of only the aromatic ring structure, and a part thereof may include a chain structure or an alicyclic hydrocarbon structure.

Specific preferred examples of the compound represented by the formula (d-1) include compounds having n1=0, such as 4,4′-diaminodiphenylamine and 2,4-diaminodiphenylamine; n1=1. Examples of the compound include 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, 1, 3-bis(4-aminobenzyl)thiourea, 1,3-bis(2-aminobenzyl)urea, 1,3-bis(2-aminophenethyl)urea, 1,3-bis(2-(2-aminobenzoyl) And (oxy)ethyl)urea, 1,3-bis(3-(2-aminobenzoyloxy)propyl)urea and the like; In addition, as a compound represented by the said Formula (d-1), these compounds can be used individually by 1 type or in combination of 2 or more types.

(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 1-12. 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. Further, from the viewpoint of improving rubbing resistance while maintaining good liquid crystal alignment, m1=0 is preferable, and from the viewpoint of reducing the pretilt angle of liquid crystal molecules, m1 is an integer of 1 to 3. Is preferred.
The bonding position of the primary amino group on the benzene ring is not particularly limited, but each primary amino group is preferably 3-position or 4-position with respect to the other groups, and 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 may be substituted.

Specific preferred 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, Examples thereof include 1,3-bis(4-aminophenylsulfanyl)propane and 1,4-bis(4-aminophenylsulfanyl)butane. As the compound represented by the 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 above formula (d-3), R ³ is a monovalent hydrocarbon group having 1 to 12 carbon atoms. Specific examples of R ³ include an alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a t-butyl group, a pentyl group, a hexyl group, an octyl group and a decyl group; a vinyl group. , Alkenyl groups such as allyl groups; cycloalkyl groups such as cyclopentyl groups and cyclohexyl groups; aryl groups such as phenyl groups and tolyl groups; aralkyl groups such as benzyl groups. The carbon number of R ³ is preferably 1 to 6, and more preferably 1 to 3. 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 R ³ above. 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 both are preferably hydrogen atoms.
In the diaminophenyl group of the above formula (d-3), the bonding positions of the two primary amino groups are not particularly limited, but the 2,4-position or 2 position relative to the group having an N-allyl structure bonded to the benzene ring. , 5-position is preferable, and 2,4-position is more preferable. 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 may be substituted.

Specific preferred examples of the compound represented by the above 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), and the like.

(Compound represented by Formula (d-4))
In the formula (d-4), the divalent group represented by "-X ⁴ -(R ⁷ -X ⁵ ) _k- " is an alkanediyl group having 1 to 3 carbon atoms, *-O-, *. It is preferably —COO— or *—O—C ₂ H ₄ —O— (however, the bond marked with “*” bonds to the diaminophenyl group).
The group “—C _c H _2c+1 ” is preferably linear, and specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, and an n-hexyl group. 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 Group, n-octadecyl group, n-nonadecyl group, n-eicosyl group and the like.
The two primary amino groups in the diaminophenyl group are preferably 2,4-position or 3,5-position with respect 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 may be substituted.

Specific preferred examples of the compound represented by the above formula (d-4) include 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 ¹ 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 ² is —O—, —COO—, —OCO. -, - NHCO -, - CONH- or -CO- indicates, ^{a 3} represents a monovalent organic group having a steroid skeleton.
As the alkanediyl group having 1 to 12 carbon atoms in A ¹ of the above formula (d-5), an alkanediyl group having 1 to 4 carbon atoms is preferable, and a methylene group, an ethylene group, a 1,3-propanediyl group, 1 The 4,4-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 -Perfluorobutanediyl group is more preferred.
The A ^2, -O- is preferable.
The steroid skeleton in A ³ refers to a structure composed of a cyclopentano-perhydrophenanthrene nucleus or a structure in which one or more carbon-carbon bonds thereof are double bonds. The monovalent organic group having such a steroid skeleton preferably has 17 to 40 carbon atoms.

Preferred specific examples of the compound represented by the above formula (d-5) include 1-cholesteryloxymethyl-2,4-diaminobenzene and 1-cholesteryloxymethyl-3, from the viewpoint of giving a high pretilt angle. 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-difluoromethyl)-3,5-diaminobenzene , 3-(2,4-diaminophenylmethoxy)-4,4-dimethylcholestane, 3-(1-(2,4-diaminophenyl)-1,1-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)cholan-24-acid hexadecyl, 3-(1-(2,4-diaminophenyl)-1,1-difluoromethoxy)cholan-24-acid hexadecyl,3 -((3,5-Diaminophenyl)methoxy)cholan-24-acid hexadecyl, 3-(1-(3,5-diaminophenyl)-1,1-difluoromethoxy)cholan-24-acid hexadecyl, 3-( 2,4-Diaminophenylmethoxy)cholan-24-acid stearyl, 3-(1-(2,4-diaminophenyl)-1,1-difluoromethoxy)cholan-24-acid stearyl, 3-(3,5- Diaminophenylmethoxy)cholan-24-acid stearyl, 3-(1-(3,5-diaminophenyl)-1,1-difluoromethoxy)cholan-24-acid stearyl, 1-cholesteryloxy-2,4-diamino It is preferable to use one or more selected from the group consisting of benzene, cholesteryl 3,5-diaminobenzoate, 1-cholestaniloxy-2,4-diaminobenzene and cholestanyl 3,5-diaminobenzoate, and Among these, 1-cholesteryloxy-2,4-diaminobenzene, cholesteryl 3,5-diaminobenzoate, and 1-cholestaniloxy-2,4-diamino are preferred because they give a particularly high pretilt angle with a small use ratio. benzene And it is particularly preferable to use one or more selected from the group consisting of cholestanyl 3,5-diaminobenzoate.

When synthesizing the polyamic acid, the specific diamine can be appropriately selected and used from the above compounds according to the driving mode of the liquid crystal display device to be manufactured. 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 produced. .. 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 A liquid crystal aligning agent suitable for a device can be produced, and at least one selected from the group consisting of the group represented by the above formula (d-4) and the compound represented by the above 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 diamine)
As the diamine used for synthesizing the polyamic acid, a compound (other diamine) other than the above specific diamine may be used. Examples of the other diamine include aliphatic diamine, alicyclic diamine, aromatic diamine, and diaminoorganosiloxane. Specific examples of these other diamines include aliphatic diamines such as metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 1,3-bis(aminomethyl)cyclohexane. As alicyclic diamine, for example, 1,4-diaminocyclohexane, 4,4′-methylenebis(cyclohexylamine) and the like;

Examples of aromatic diamines include p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl sulfide, 1,5-diaminonaphthalene, 2,2′-dimethyl-4,4′-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-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-bis(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-aminophenyl)-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-1,3,3-trimethyl-1H-indene-6-amine, 4-(4'-trifluoromethoxybenzoi Roxy)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-heptyl Cyclohexane, 1,1-bis(4-((aminophenyl)methyl)phenyl)-4-(4-heptylcyclohexyl)cyclohexane, 4-aminobenzyl Min, 3-aminobenzylamine, 2,2-bis[4-(4-aminophenoxy)phenyl]propane and the like;
Examples of the diaminoorganosiloxane include 1,3-bis(3-aminopropyl)-tetramethyldisiloxane and the like, and the diamine described in JP 2010-97188 A can be used. In addition, these other diamines can be used individually by 1 type or in combination of 2 or more types.

（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 invention contains a specific amine compound (C) described in detail below as an additive, it has a carboxyl group as at least a part of the other diamine used for the synthesis of polyamic acid. It is preferable to include a diamine (hereinafter, also referred to as “carboxyl group-containing diamine”). The carboxyl group-containing diamine is preferably an aromatic diamine, and specific examples thereof include compounds represented by the following formulas (e1-1) and (e1-2).

(In formula (e1-1) and 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, and Z ¹ is a single bond, It is 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 formula (e1-1) and formula (e1-2), examples of the alkyl group having 1 to 10 carbon atoms in 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 and the like, 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.
Examples of the alkanediyl group having 1 to 3 carbon atoms in Z ¹ include a methylene group, an ethylene group, a trimethylene group, a prepylene group and the like.
r1, r3 and r4 are preferably 0 or 1, and more preferably 0.

Specific examples of the carboxyl group-containing diamine include compounds represented by the following formula (e1-1), such as 3,5-diaminobenzoic acid, 2,4-diaminobenzoic acid, and 2,5-diaminobenzoic acid. 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, 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'-diaminodiphenylethane-3- Carboxylic acid, 4,4'-diaminodiphenyl ether-3,3'-dicarboxylic acid, 4,4'-diaminodiphenyl ether-3-carboxylic acid and the like can be mentioned.

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 thereof used is preferably 10 mol% or more, and more preferably 30 mol% or more, based on all diamines. .. When the compound represented by the formula (d-2) is used, the amount thereof used 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 preferable that the amount is 30 mol% or more, more preferably 50 mol% or more.
When the compound represented by the above formula (d-3) is used, the amount thereof is preferably 5 mol% or more based on all diamines from the viewpoint of improving the stability of the voltage holding ratio. More preferably, it is 10 mol% or more.

When 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) is used, it is used from the viewpoint of imparting good orientation. The amount (the total amount when two or more compounds are used) is preferably 5 mol% or more, and more preferably 10 mol% or more, based on all diamines. As the specific diamine, one of the compounds exemplified above may be used alone or in combination of two or more.
When a carboxyl group-containing diamine is used as the other diamine, the use ratio thereof is preferably 5 mol% or more of the carboxyl group-containing diamine, more preferably 10 to 90 mol%, based on all diamines. ˜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。） In the case of producing a liquid crystal aligning agent for a TN type liquid crystal display device, tetracarboxylic dianhydride and A monoamine represented by the following formula (m-1) may be used together with the diamine.

(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 above 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. , Hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group and the like, which may be linear or branched. Examples of the alkoxy group having 6 to 20 carbon atoms include a group (-OR ²³ ) in which the above-exemplified alkyl group having 6 to 20 carbon atoms is bonded to an oxygen atom.

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 the hydrocarbon group. In the meantime, a group having a functional group such as -O-, -CO-, -COO-, -S-, a heterocycle-containing group and the like can be mentioned. Specific examples of the divalent hydrocarbon group include chain hydrocarbon groups such as methylene group, ethylene group, propanediyl group, butanediyl group, pentanediyl group, hexanediyl group, heptanediyl group, octanediyl group, Nonanediyl group, decandiyl 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 As; alicyclic hydrocarbon groups such as cyclopropylene group, cyclobutylene group, cyclopentylene group, cyclohexylene group, cyclohexenylene group, cycloheptylene group, cyclooctylene group, cyclononylene group, cyclodecylene group, cyclo Undecylene group, cyclododecylene group, cyclotridecylene group, cyclotetradecylene group, cyclopentadecylene group, cyclooctadecylene group, cycloicosylene group, bicyclohexylene group, norbornylene group, adamantylene group, etc.; aromatic Examples of the hydrocarbon group may include a phenylene group and a biphenylene group. Among them, R ²⁴ is preferably a chain hydrocarbon group, an alicyclic hydrocarbon group or an aromatic hydrocarbon group.

Specific preferred 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, 2-ethylhexylamine; p-aminophenylhexane, p-aminophenyloctane, p-aminophenyldodecane, p-aminophenylhexadecane, p-aminophenoxyoctane. , Aromatic monoamines such as p-aminophenoxydodecane and p-aminophenoxyhexadecane; and the like.

The proportion of the monoamine used is such that the tetracarboxylic dianhydride used is a mole, the diamine is b mole, and the monoamine is c, from the viewpoint of suppressing the adverse effect of the monoamine liberated in the produced liquid crystal cell on the display characteristics. It is preferable that “2(ab)≧c>0” is satisfied when the amount is molar.
The monoamine represented by the above formula (m-1) may be reacted and polymerized with the reaction product after the reaction between the tetracarboxylic acid dianhydride and the diamine, or the tetracarboxylic acid dianhydride. The three components of the anhydride, diamine and monoamine may be simultaneously reacted and polymerized.

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

Examples of the molecular weight modifier include acid monoanhydride, monoamine compound, monoisocyanate compound and the like. Specific examples of these include acid monoanhydrides such as maleic anhydride, phthalic anhydride, itaconic anhydride, n-decylsuccinic anhydride, n-dodecylsuccinic anhydride, and n-tetradecylsuccinic anhydride. Acid anhydride, n-hexadecyl succinic acid anhydride, etc.; as a monoamine compound, for example, aniline, cyclohexylamine, n-butylamine, a compound represented by the formula (m-1), etc.; as a monoisocyanate compound, Examples thereof include phenyl isocyanate and naphthyl isocyanate.
The proportion of the molecular weight modifier used is preferably 20 parts by weight or less, and more preferably 10 parts by weight or less, based on 100 parts by weight of the total 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 equivalent ratio is preferable, and the 0.3-1.2 equivalent ratio is more preferable.
The synthesis reaction of polyamic acid is preferably carried out in an organic solvent. The reaction temperature at this time is preferably −20° C. to 150° C., more preferably 0 to 100° C. 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, phenolic solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons, hydrocarbons and the like.
Specific examples of these organic solvents include N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, N-ethyl-2-pyrrolidone, N,N as the aprotic polar solvent. -Dimethylacetamide, N,N-dimethylformamide, dimethylsulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide, etc.; as the phenolic solvent, for example, phenol, m-cresol, xylenol, halogenated phenol, etc. To;

As the alcohol, for example, methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, ethylene glycol monomethyl ether and the like; as the ketone, for example, acetone, Methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and the like; examples of the above ester include ethyl lactate, butyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, diethyl oxalate and malon. Acid diethyl, isoamyl propionate, isoamyl isobutyrate, the compound represented by the above formula (b-1A), the compound represented by the above formula (b-1B) 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, 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, etc. can be mentioned respectively.

Among these organic solvents, one or more selected from the group consisting of an aprotic polar solvent and a phenolic solvent (organic solvent A), or one or more selected from organic solvent A, an alcohol, a ketone, an ester, 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 further 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 tetracarboxylic dianhydride and diamine is 0.1 to 50% by weight based on the total amount (a+b) of the reaction solution. Preferably.

As described above, a reaction solution obtained by dissolving polyamic acid is obtained. This reaction solution may be directly used for the preparation of the liquid crystal aligning agent, or may be subjected to the preparation of the liquid crystal aligning agent after isolating the polyamic acid contained in the reaction solution, or the isolated polyamic acid is purified. Alternatively, the liquid crystal aligning agent may be prepared. When a polyamic acid is dehydrated and ring-closed to form a polyimide, the reaction solution may be subjected to the dehydration ring-closing reaction as it is, or may be subjected to the dehydration ring-closing reaction after isolating the polyamic acid contained in the reaction solution. 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 known methods.

<Polyimide>
The polyimide according to the present invention can be obtained by subjecting the polyamic acid synthesized as described above to dehydration ring closure to imidize.

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

The dehydration ring closure of the polyamic acid is preferably carried out by a method of heating the polyamic acid or by dissolving the polyamic acid in an organic solvent and adding a dehydrating agent and a dehydration ring closure catalyst to the solution and heating the mixture as necessary. .. Of these, the latter method is preferable.
In the method of adding the dehydrating agent and the dehydration ring-closing catalyst to the solution of the polyamic acid, acid anhydrides such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride can be used as the dehydrating agent. 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 with respect to 1 mol of the dehydrating agent used. Examples of the organic solvent used for the dehydration ring closure reaction include the organic solvents exemplified as those used for the synthesis of polyamic acid. The reaction temperature of the dehydration ring closure reaction is preferably 0 to 180°C, more preferably 10 to 150°C. The reaction time is preferably 1.0 to 120 hours, more preferably 2.0 to 30 hours.

In this way, a reaction solution containing polyimide is obtained. This reaction solution may be directly used for the preparation of the liquid crystal aligning agent, or may be used for the preparation of the liquid crystal aligning agent after removing the dehydrating agent and the dehydration ring-closing catalyst from the reaction solution. The alignment agent may be prepared, or the isolated polyimide may be purified and then used to prepare the liquid crystal alignment agent. These purification operations can be performed according to known methods.

<Polyamic acid ester>
The polyamic acid ester contained in the liquid crystal aligning agent of the present invention is synthesized, for example, by reacting [I] the polyamic acid obtained by the above synthetic reaction with a hydroxyl group-containing compound, a halide, an epoxy group-containing compound, or the like. Can be obtained, a method of reacting a [II] tetracarboxylic acid diester with a diamine, and a method of reacting a [III] tetracarboxylic acid diester dihalide with a diamine.

Examples of the hydroxyl group-containing compound used in the method [I] include alcohols such as methanol, ethanol and propanol; phenols such as phenol and cresol. Examples of the halide include methyl bromide, ethyl bromide, stearyl bromide, methyl chloride, stearyl chloride, 1,1,1-trifluoro-2-iodoethane, and the like. Examples include propylene oxide and the like. The tetracarboxylic acid diester used in the method [II] can be obtained, for example, by ring-opening the tetracarboxylic dianhydride exemplified in the synthesis of the above polyamic acid using the above alcohols. The tetracarboxylic acid diester dihalide used in the method [III] can be obtained by reacting the tetracarboxylic acid diester obtained as described above with an appropriate chlorinating agent such as thionyl chloride. As the diamine used in the methods [II] and [III], the diamine and the like exemplified in the synthesis of the above polyamic acid can be used. The polyamic acid ester may have only an amic acid ester structure, or may be a partial 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 the solution has a concentration of 10% by weight, and preferably 15 to 500 mPas. More preferably, it has a solution viscosity of s. In addition, the solution viscosity (mPa·s) of the above-mentioned polymer is based on a polymer solution having a concentration of 10% by weight prepared using a good solvent for the polymer (for example, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.). , A value measured at 25° C. using an E-type rotational viscometer.
The reduced viscosity is not particularly limited as long as it can form a uniform coating film, but it is preferably 0.05 to 3.0 dl/g, and 0.1 to 2.5 dl/g. Is more preferable, and 0.3 to 1.5 dl/g is even more preferable.
Regarding the polyamic acid, polyimide and polyamic acid ester contained in the liquid crystal aligning agent according to the present invention, the weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC) is preferably 500 to 100,000, It is more preferably 1,000 to 50,000.

≪Solvent≫
The liquid crystal aligning agent according to the present invention has, as a solvent component, at least one organic solvent selected from the group consisting of a compound represented by the above formula (b-1A) and a compound represented by the above formula (b-1B) ( Contains a specific solvent (B)). By including such a specific solvent (B) in the liquid crystal aligning agent, the coating property of the liquid crystal aligning agent on the substrate and the storage stability of the liquid crystal aligning agent can be improved, and the liquid crystal display element can have a narrow frame. Good display quality can be maintained even when this is done.

[Specific solvent (B)]
(Compound represented by Formula (b-1A))
Regarding the compound represented by the formula (b-1A), examples of the monovalent hydrocarbon group having 1 to 5 carbon atoms in R ^{8 to} R ¹⁰ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, Butyl group, isobutyl group, tertiary butyl group, pentyl group, neopentyl group, and other alkyl groups having 1 to 5 carbon atoms; vinyl group, allyl group, and other C2 or C3 monovalent unsaturated chain hydrocarbons Groups; and the like. Among these, R ^{8 to} R ¹⁰ are preferably methyl groups or ethyl groups, and more preferably all R ^{8 to} R ¹⁰ are methyl groups. Note that R ^{8 to} R ¹⁰ may be the same or different from each other.
Specific preferred examples of the compound represented by the above formula (b-1A) include alkyl 2-hydroxyisobutyrate, and examples thereof include methyl 2-hydroxyisobutyrate. As the compound represented by the above formula (b-1A), the above compounds may be used alone or in combination of two or more.

(Compound represented by Formula (b-1B))
Regarding the compound represented by the formula (b-1B), specific examples of the monovalent hydrocarbon group having 1 to 5 carbon atoms in R ⁸ , R ⁹ and R ¹¹ include R of the formula (b-1A). The description of ^{8 to} R ¹⁰ can be applied. Among them, R ⁸ and R ⁹ are preferably a hydrogen atom, a methyl group or an ethyl group, respectively. R ¹¹ is preferably an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group or a neopentyl group, and particularly preferably an n-butyl group. R ⁸ , R ⁹ and R ¹¹ may be the same or different.
X is an OH group or an SH group, and preferably an OH group. n is 0 or 1, and preferably 0.
Preferable specific examples of the compound represented by the above formula (b-1B) include alkyl glycolate, for example, butyl glycolate. As the compound represented by the above formula (b-1B), the above compounds can be used alone or in combination of two or more.

(Other solvents)
The liquid crystal aligning agent of the present invention preferably contains a solvent other than the specific solvent (B) as a solvent component. As the other solvent, a solvent capable of dissolving the polymer (A) (hereinafter, also referred to as “first solvent”), a poor solvent for the polymer (A) and other than the specific solvent (B) are used. An organic solvent etc. can be mentioned.
The first solvent may be a good solvent for the polymer (A), and preferred specific 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 can be mentioned. The first solvent may be one of the above solvents or a mixture of two or more thereof.

Examples of the poor solvent for the polymer (A) other than the specific solvent (B) (hereinafter, also referred to as “other poor solvent”) include, for example, ethylene glycol monomethyl ether, butyl lactate, acetic acid. Butyl, methyl methoxypropionate, ethyl ethoxy propionate, 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 Examples thereof include isobutyrate, ethylene carbonate, propylene carbonate, diacetone alcohol, diethylene glycol diethyl ether, diisopentyl ether and propylene glycol diacetate. The said organic solvent can use the above thing individually by 1 type or in mixture of 2 or more types. In addition, below, the group which consists of the said other poor solvent and specific solvent (B) is also called "2nd solvent."

Among the other solvents, the content ratio of the first solvent is preferably 5% by weight or more based on the total amount of the solvent contained in the liquid crystal aligning agent, from the viewpoint of suppressing precipitation of the polymer (A). %, more preferably 10% by weight or more, further preferably 20% by weight or more. Further, the upper limit of the content ratio of the first solvent is preferably 95% by weight with respect to 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 90% by weight or less, and further preferably 85% by weight or less.
The content ratio of the organic solvent other than the specific solvent (B) in the second solvent is preferably 80% by weight or less, and more preferably 70% by weight, based on the total amount of the solvent contained in the liquid crystal aligning agent. Or less, more preferably 50% by weight or less, and particularly preferably 30% by weight or less.
The ratio of the first solvent to the second solvent is such that the amount of the second solvent used is 0.03 times (weight) or more with respect to the amount of the first solvent used, from the viewpoint of good coatability on the substrate. Is preferable, 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, and more preferably 2.0 times (weight) or less.

The liquid crystal aligning agent according to the present invention preferably contains substantially no butyl cellosolve as a solvent. Butyl cellosolve has conventionally been generally used as a solvent component for improving the coating property of a liquid crystal aligning agent on a substrate when preparing the liquid crystal aligning agent. However, when butyl cellosolve is used, when it is stored for a long period of time, for example, in an extremely low temperature environment of −15° C. or less, a precipitate tends to be generated in the liquid crystal aligning agent. In addition, a product stored at low temperature may be transported in a state of being stored in dry ice, and is often exposed to a lower temperature (for example, −20° C. or lower). In that case, precipitates are more likely to occur in the liquid crystal aligning agent. On the other hand, the specific solvent (B) does not easily generate a precipitate in the liquid crystal aligning agent even when the liquid crystal aligning agent is stored at a low temperature for a long time, and imparts excellent storage stability to the liquid crystal aligning agent. It is possible. Further, the specific solvent (B) imparts excellent coatability to the liquid crystal aligning agent, and is therefore useful as a substitute for butyl cellosolve.
In the present 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 based on the total amount of the solvent contained in the liquid crystal aligning agent. It means not more than 0.5% by weight, more preferably not more than 0.5% by weight.

A liquid crystal display is manufactured by arranging a pair of substrates having a liquid crystal alignment film facing each other, and arranging liquid crystal between the pair of substrates facing each other. At that time, the pair of substrates are attached to each other by using a sealing agent such as an epoxy resin. Here, in a touch panel type display panel represented by a smartphone or a tablet PC, it has been attempted to narrow the frame in order to make the movable area of the touch panel wider and to make the liquid crystal panel (element) smaller. ing. With the narrowing of the frame of the liquid crystal panel, display unevenness may be visually recognized around the sealant, which is not sufficiently satisfactory in terms of display quality. In order to achieve higher definition and longer life of the liquid crystal display, a liquid crystal display element in which such display unevenness around the sealant is difficult to be visually recognized (high resistance to bezel unevenness) is required.
When the above specific solvent (B) is contained as the solvent component of the liquid crystal aligning agent, precipitates are unlikely to be generated in the aligning agent even when stored in a low temperature environment for a long period of time, and storage stability is good. is there. Further, the coating property of the liquid crystal aligning agent on the substrate is also good. Further, a liquid crystal display element having good display quality can be obtained even if the liquid crystal display element has a narrow frame. Further, when at least a part of the polymer component is the polymer (A) obtained by using the above-mentioned specific diamine, the above effect is high and suitable.

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

[Other polymers]
The above-mentioned other polymers can be used for improving solution properties and electrical properties. Examples of such other polymers include polyesters, polyamides, cellulose derivatives, polyacetals, polystyrene derivatives, poly(styrene-phenylmaleimide) derivatives, poly(meth)acrylates, and the like. 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 polymer components in the liquid crystal aligning agent. It is preferably 0.1 to 30% by weight, and further preferably.

[Epoxy group-containing compound]
The epoxy group-containing compound can be used to improve the adhesiveness of the liquid crystal alignment film with 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, 1 ,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′-diaminodiphenylmethane, N,N-diglycidyl-benzylamine, N, Examples thereof include N-diglycidyl-aminomethylcyclohexane and N,N-diglycidyl-cyclohexylamine.
When these epoxy group-containing compounds are added to the liquid crystal aligning agent, the mixing ratio is preferably 40 parts by weight or less, and 0.1 to 30 parts by weight, based on 100 parts by weight of the total amount of the 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 aligning agent. Examples of such a functional silane compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N-(2-aminoethyl). )-3-Aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3- Aminopropyltrimethoxysilane, N-triethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-trimethoxysilyl Methyl-3,6-diazananoate, N-benzyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, glycidoxymethyltrimethoxysilane, 2-glycidoxyethyltrimethoxysilane , 3-glycidoxypropyltrimethoxysilane and the like.
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, and more preferably 0.02 to 0.2 parts by weight, based on 100 parts by weight of the total amount of the polymer.

[Amine compound (C)]
The amine compound (C) has one primary amino group and a nitrogen-containing aromatic heterocycle, 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 electric characteristics of the liquid crystal display device (for example, voltage holding ratio and relaxation rate of residual charge).

The nitrogen-containing aromatic heterocycle in the amine compound (C) may be an 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 (oxygen atom, sulfur atom, etc.) other than the nitrogen atom. Specific examples of the nitrogen-containing aromatic heterocycle 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, Examples thereof include an oxadiazole ring. Further, the nitrogen-containing aromatic heterocycle may be one in which a substituent is introduced into the carbon atom constituting the above exemplified ring. Examples of the substituent include a halogen atom, an alkyl group, an alkoxy group and the like.

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

（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 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. The primary amino group in the formula is bonded to the chain hydrocarbon group or alicyclic hydrocarbon group which A ¹ has.)

In the above formula (c-1), the divalent organic group for A ¹ is, for example, a divalent chain hydrocarbon group, a divalent alicyclic hydrocarbon group, —OR ²¹ —, —CO. -R ²¹ - (. ^{However, R 21} is a divalent a chain hydrocarbon group or an alicyclic hydrocarbon group). Further, as the divalent organic group, —O—, —NH—, —CO—O— are present 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 ) A divalent group having an aromatic hydrocarbon group such as _2- O- and a phenylene group, a heterocyclic group such as a pyridinylene group; and a divalent chain hydrocarbon group or a divalent alicyclic hydrocarbon group. A divalent group in which at least one hydrogen atom is substituted with a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom or an iodine atom, an aromatic hydrocarbon group such as a phenyl group, a hydroxyl group or a halogenated alkyl group; And so on. Specific examples of the divalent chain hydrocarbon group and alicyclic hydrocarbon group for A ¹ can be applied to the description of R ²⁴ in the formula (m-1).

Among the above, 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 1 to 15 carbon atoms, and further preferably 1 to 10 carbon atoms. The above description is applied to the nitrogen-containing aromatic heterocycle of A ² .

Specific examples of the amine compound (C) include compounds represented by the following formulas (c-1-1) to (c-1-32). As the amine compound (C), one of these may be used alone or two or more of them may be used in combination.

When the above-mentioned amine compound (C) is added to the liquid crystal aligning agent, the compounding ratio is 1 part by weight based on 100 parts by weight of the total amount of the polymer from the viewpoint of suitably obtaining the effect of the addition of the amine compound (C). It is preferably at least 1 part by weight, more preferably at least 2 parts by weight. Further, from the viewpoint of not impairing the stability of the liquid crystal aligning agent, it is preferably 20 parts by weight or less, and more preferably 15 parts by weight or less, based on 100 parts by weight of the total amount of the polymer.
As other additives to be contained in the liquid crystal aligning agent, in addition to the above, compounds having at least one oxetanyl group in the molecule, antioxidants and the like can be used.

When the above-mentioned amine compound (C) is contained in the liquid crystal aligning agent according to the present invention as an additive, the above polymer (A) is preferable in that the electric characteristics of the liquid crystal display device can be suitably improved. It preferably has a carboxyl group. Further, the number of carboxyl groups contained in the polymer (A) is preferably 0.1 to 3 on average per repeating unit of the polymer (A), and is 0.3 to 2. Is more preferable, and it is further 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, and for example, (i) a method by adjusting the imidization ratio of the polyimide, (ii) for synthesizing the polymer (A) Examples include a method of adjusting the carboxyl group content of the diamine used. Alternatively, the above (i) and (ii) may be used in combination. From the viewpoint of increasing the degree of freedom of the imidization 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 the 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 is preferable, 0.05 to 1 mol is more preferable, and 0.08 to 0.8 mol is further preferable.

The solid content concentration of the liquid crystal aligning agent according to the present invention (the ratio of the total weight of components other than the solvent of the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) is appropriately selected in consideration of viscosity, volatility and the like. However, it is preferably in the range of 1 to 10% by weight. That is, the liquid crystal aligning agent according to the present invention is applied to the surface of the substrate as described later, and preferably heated to form a coating film which is a liquid crystal alignment film or a coating film which becomes a liquid crystal alignment film, At this time, if the solid content concentration is less than 1% by weight, the film thickness of the coating film becomes too small to obtain a good liquid crystal alignment film. On the other hand, when the solid content concentration exceeds 10% by weight, the film thickness of the coating film becomes excessive and it is difficult to obtain a good liquid crystal alignment film, and the viscosity of the liquid crystal alignment agent increases, resulting in poor coating properties. Becomes

The particularly preferable range of the solid content concentration depends on the method used when the liquid crystal aligning agent is applied to the substrate. For example, in the case of the spin coating method, the solid content concentration range of 1.5 to 4.5% by weight is particularly preferable. In the case of using the offset printing method, it is particularly preferable that the solid content concentration is in the range of 3 to 9% by weight, and thus the solution viscosity is in the range of 12 to 50 mPa·s. In the case of using the inkjet method, it is particularly preferable that the solid content concentration is in the range of 1 to 8% by weight, and thus the solution viscosity is in the range of 3 to 20 mPa·s. The temperature for preparing the liquid crystal aligning agent of the present invention is preferably 10 to 50°C, more preferably 20 to 30°C.

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

The liquid crystal display element according to the present invention can be manufactured, for example, by the following steps (1) to (3). In step (1), the substrate used differs depending on the desired drive 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 invention is applied onto a substrate, and then the applied 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 set as a pair, and on each transparent conductive film formation surface thereof, The liquid crystal aligning agent according to the present invention 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 glass such as float glass or soda glass; a transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, polycarbonate, poly (alicyclic olefin) can be used. As the transparent conductive film provided on one surface of the substrate, a NESA film made of tin oxide (SnO ₂ ) (registered trademark of PPG Co., USA), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ) and the like are used. Can be used. To obtain a patterned transparent conductive film, for example, a method of forming a pattern by photo-etching after forming an unpatterned transparent conductive film, a method of using a mask having a desired pattern when forming the transparent conductive film, etc. be able to. When applying the liquid crystal aligning agent, in order to further improve the adhesion between the substrate surface and the transparent conductive film and the coating film, the surface of the substrate surface on which the coating film is to be formed is functional silane compound or functional titanium. A pretreatment of applying a compound or the like in advance may be performed.

After the application of the liquid crystal aligning agent, preheating (prebaking) is preferably carried out for the purpose of preventing liquid drip of the applied aligning agent. The prebaking temperature is preferably 30 to 200°C, more preferably 40 to 150°C, and particularly preferably 40 to 100°C. The prebaking time is preferably 0.25 to 10 minutes, more preferably 0.5 to 5 minutes. Then, a baking (post-baking) step is carried out for the purpose of completely removing the solvent and, if necessary, thermal imidization of the amic acid structure present in the polymer. The baking (post-baking) temperature is preferably 80 to 300°C, more preferably 120 to 250°C. The post-baking time is preferably 5 to 200 minutes, more preferably 10 to 100 minutes. The thickness of the film thus formed is preferably 0.001 to 1 μm, more preferably 0.005 to 0.5 μm.

(1-2) When manufacturing an IPS-type or FFS-type liquid crystal display element, an electrode formation surface of a substrate provided with an electrode formed of a comb-shaped patterned transparent conductive film or a metal film, and an electrode are provided. The liquid crystal aligning agent according to the present invention is applied to one surface of a counter substrate which is not formed, and then each applied surface is heated to form a coating film. The materials of the substrate and the transparent conductive film used at this time, the coating method, the heating conditions after coating, the patterning method of the transparent conductive film or the metal film, the pretreatment of the substrate, and the preferable film thickness of the coating film formed are as described above. It 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 each of the cases (1-1) and (1-2) described above, after the liquid crystal aligning agent is applied onto 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 a coating film, The coating film may be further imidized by proceeding with the dehydration ring closure reaction.

[Step (2): Orientation ability imparting treatment]
When manufacturing a TN-type, STN-type, IPS-type, or FFS-type liquid crystal display element, the coating film formed in the above step (1) is subjected to a treatment for imparting a liquid crystal aligning ability. As a result, the alignment ability of the liquid crystal molecules is imparted to the coating film to form a liquid crystal alignment film. Examples of the treatment include a rubbing treatment in which the coating film is rubbed in a certain direction with a roll wound with a cloth made of fibers such as nylon, rayon, and cotton, and a photo-alignment treatment in which the coating film is irradiated with polarized or non-polarized radiation. Is mentioned. On the other hand, in the case of producing 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, as the radiation applied to the coating film, for example, ultraviolet rays and visible rays containing light with a wavelength of 150 to 800 nm can be used. When the radiation is polarized light, it may be linearly polarized light or partially polarized light. When the radiation used is linearly polarized light or partially polarized light, the irradiation may be performed in a direction perpendicular to the substrate surface, an oblique direction, or a combination thereof. When irradiating non-polarized radiation, the irradiation direction is an oblique direction.
As the light source 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, etc. can be used. Ultraviolet rays in a preferable wavelength range can be obtained by means of using a light source in combination with a filter, a diffraction grating, or the like. The irradiation dose of radiation is preferably 100 to 50,000 J/m ² , and more preferably 300 to 20,000 J/m ² . The coating film may be irradiated with light while heating the coating film in order to increase the 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.

It should be noted that the liquid crystal alignment film after the rubbing treatment is further processed by irradiating a part of the liquid crystal alignment film with ultraviolet rays to change the pretilt angle of a part of the liquid crystal alignment film, A resist film may be formed on each part and then a rubbing process may be performed in a direction different from the previous rubbing process, and then the resist film may be removed so that the liquid crystal alignment film has different liquid crystal aligning ability for each region. .. In this case, it is possible to improve the visual field characteristics of the obtained liquid crystal display element. The liquid crystal alignment film suitable for a VA type liquid crystal display element can also be suitably used for a PSA (Polymer sustained alignment) type liquid crystal display element.

[Step (3): Construction of liquid crystal cell]
A liquid crystal cell is manufactured by preparing two substrates on which the liquid crystal alignment film is formed as described above, and disposing the liquid crystal between the two substrates that are opposed to each other. To manufacture a liquid crystal cell, for example, the following two methods can be mentioned.
The first method is a conventionally known method. First, two substrates are arranged to face each other with a gap (cell gap) so that the respective liquid crystal alignment films face each other, and the peripheral portions of the two substrates are bonded together by using a sealant, and the substrate surface and the sealant are attached. A liquid crystal cell is manufactured by injecting and filling a liquid crystal into the cell gap partitioned by, and then sealing the injection 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 place on one of the two substrates on which the liquid crystal alignment film is formed, and then liquid crystal is dropped onto predetermined places on the liquid crystal alignment film surface. After that, the other substrate is bonded so that the liquid crystal alignment films face 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 manufacturing a liquid crystal cell. .. In either case, the liquid crystal cell produced as described above is further heated to a temperature at which the liquid crystal used has an isotropic phase, and then gradually cooled to room temperature, so that the flow orientation at the time of filling the liquid crystal is improved. It is desirable to remove it.

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

Then, a liquid crystal display element can be obtained by attaching a polarizing plate to the outer surface of the liquid crystal cell. As a polarizing plate to be attached to the outer surface of a liquid crystal cell, a polarizing plate in which a polarizing film called “H film” in which polyvinyl alcohol is stretched and oriented to absorb iodine and sandwiched between cellulose acetate protective films or the H film itself is used. A polarizing plate consisting of When the coating film is rubbed, the two substrates are arranged 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 invention can be effectively applied to various devices, for example, watches, portable games, word processors, notebook computers, car navigation systems, camcorders, PDAs, digital cameras, mobile phones, smartphones. It can be used for display devices such as various monitors and liquid crystal televisions.

Hereinafter, the present invention will be described more specifically by way of examples, but the present invention is not limited to these examples.

In the following Examples and Comparative Examples, the imidization ratio of the polyimide in the polymer solution and the weight average molecular weight Mw of the polymer were measured by the following methods.
[Imidization rate of polyimide]
The polyimide solution was poured into pure water, the obtained precipitate was sufficiently dried under reduced pressure at room temperature, then 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 imidization ratio [%] was calculated by the following mathematical formula (x).
Imidization rate [%]=(1−A ¹ /A ² ×α)×100 (x)
(In Formula (x), A ¹ is a peak area derived from a proton of an NH group appearing in the vicinity of a chemical shift of 10 ppm, A ² is a peak area derived from another proton, and α is a precursor of a polymer (polyamic acid). The ratio of the number of other protons to one proton of the NH group in ).)
[Weight average molecular weight of polymer]
The weight average molecular weight Mw is a polystyrene conversion value measured by gel permeation chromatography under the following conditions.
Column: TOSgel GRCXLII manufactured by Tosoh Corporation
Solvent: Tetrahydrofuran Temperature: 40°C
Pressure: 68 kgf/cm ²

<<First Example>>
[Example 1A]
In a 50 ml four-necked flask equipped with a stirrer and a nitrogen introduction tube, 0.60 g (2.0 mmol) of 1,3-bis(4-aminophenethyl)urea (BAPU) as a diamine, and p-phenylenediamine (p-PDA). ) 1.95 g (18.0 mmol) was added, 30 g of N-methyl-2-pyrrolidone (NMP) was added, and it was dissolved by stirring while feeding nitrogen. While stirring this diamine solution, 3.70 g (18.9 mmol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA) was added as a tetracarboxylic dianhydride, and the solid content concentration was further increased. NMP was added so as to be 12% by weight, 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 methyl 2-hydroxyisobutyrate (HBM) as a specific solvent (B) were added (NMP:HBM=60:40 (weight ratio)), and the polyamic acid concentration was 6.0% by weight. A liquid crystal aligning agent (S1A) was prepared so that

[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 and the mixture was dissolved at room temperature for 10 minutes. Reacted for hours. The polymerization reaction proceeded easily and uniformly to obtain polyamic acid (PA-2). To this NMP solution of polyamic acid (PA-2), NMP and methyl 2-hydroxyisobutyrate (HBM) as a specific solvent (B) were added (NMP:HBM=50:50 (weight ratio)) to obtain a polyamic acid concentration. The liquid crystal aligning agent (S2A) was prepared in such a manner that the content was 6.0% by weight.

[Example 3A]
22.42 g (0.1 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as a tetracarboxylic acid dianhydride, and 18.73 g of 4,4′-diaminodiphenylamine (4,4′DADPA) as a 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 to obtain polyamic acid (PA-3). To this NMP solution of polyamic acid (PA-3), NMP and methyl 2-hydroxyisobutyrate (HBM) as a specific solvent (B) were added (NMP:HBM=80:20 (weight ratio)), and the polyamic acid concentration The liquid crystal aligning agent (S3A) was prepared so that the content of the liquid crystal aligning agent was 6.0% by weight.

[Example 4A]
As 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). Compound (15.22 g, 0.04 mol) is dissolved in 165 g of NMP, and 19.41 g (0.099 mol) of CBDA as a tetracarboxylic dianhydride is added thereto, and the mixture is allowed to react at room temperature for 24 hours to give a polyamic acid (PA). A solution containing -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 methyl 2-hydroxyisobutyrate (HBM) as a specific solvent (B) were added (NMP:HBM=80:20 (weight ratio)), and a liquid crystal aligning agent having a concentration of 4.5% by weight ( S4A) 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 (DA-3) were mixed in 20.0 g of NMP to form tetracarboxylic acid dianhydride. 2.85 g (14.5 mmol) of CBDA was added as a product, and 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 the obtained polyamic acid solution 40.0 g, NMP and methyl 2-hydroxyisobutyrate (HBM) as a specific solvent (B) were added (NMP:HBM=75:25 (weight ratio)) to obtain a polyamic acid concentration. The liquid crystal aligning agent (S5A) was prepared so that the content of the liquid crystal aligning agent was 4.0% by weight.

[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 were dissolved in 43 g of NMP, and the mixture was reacted at 20° C. for 4 hours with stirring to react the polyamic acid (PA-6 ) Was obtained. Then, NMP and methyl 2-hydroxyisobutyrate (HBM) as a specific solvent (B) were added to the obtained NMP solution of polyamic acid (PA-6) (NMP:HBM=35:65 (weight ratio)). The liquid crystal aligning agent (S6A) was prepared so that the solid content concentration was 3.0% by weight.

[Example 7A]
8.724 g (0.04 mol) of pyromellitic dianhydride (PMDA) as a tetracarboxylic dianhydride, 2.877 g (0.0266 mol) of p-PDA as a diamine and 4.567 g (0.012 mol) of PCH7DAB were added to NMP91. A solution containing polyamic acid (PA-7) was prepared by reacting in 0.6 g for 3 hours at room temperature. To 25 g of this polyamic acid solution, NMP and methyl 2-hydroxyisobutyrate (HBM) as a specific solvent (B) were added (NMP:HBM=60:40 (weight ratio)), and the solid content concentration was 5.0 weight. The liquid crystal aligning agent (S7A) was prepared so that the content of the liquid crystal aligning agent was S.

[Example 8A]
14.4-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 the polyamic acid intermediate (PA-8). To this NMP solution of the polyamic acid intermediate, NMP and methyl 2-hydroxyisobutyrate (HBM) as a specific solvent (B) were added (NMP:HBM=60:40 (weight ratio)), and the solid content concentration was 6.0. A wt% liquid crystal aligning agent (S8A) was prepared.

[Example 9A]
As a tetracarboxylic dianhydride, bicyclo[3.3.0]octane-2,4,6,8-tetracarboxylic acid 2:4,6:8-dianhydride (BODA) 4.50 g (0.018 mol) 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, they were further reacted at 40° C. for 43 hours. NMP was added to 42 g of the polyamic acid solution to prepare a 1 wt% solution, and 4.18 g of acetic anhydride and 6.48 g of pyridine were added as an imidization catalyst to the solution, and the mixture was reacted at room temperature for 30 minutes and at 120° C. for 2 hours. Let 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-1)) was 72%. To this powder, NMP and methyl 2-hydroxyisobutyrate (HBM) as a specific solvent (B) were added and dissolved (NMP:HBM=50:50 (weight ratio)) so that the solid content concentration becomes 4.5% by weight. A liquid crystal aligning agent (S9A) was prepared.

[Comparative Examples 1A to 9A]
Regarding the solvent composition of the liquid crystal aligning agent, a polymer was used in the same manner as in Examples 1A to 4A, 6A to 9A, and Reference Example 5A except that butyl cellosolve (BC) was used as the second solvent instead of the specific solvent (B). And a liquid crystal aligning agent were prepared to obtain liquid crystal aligning agents (R1A) to (R9A). Comparative example XA (X is an integer of 1 to 9) is an example corresponding to example XA and reference example XA. That is, in Comparative Example XA, a liquid crystal aligning agent was prepared in the same manner as in Example XA and Reference Example XA, except that the same polymer as in Example XA and Reference Example XA was synthesized and butyl cellosolve was used instead of the specific solvent (B). Was prepared.

[Example 10A]
As a tetracarboxylic dianhydride, bicyclo[3.3.0]octane-2,4,6,8-tetracarboxylic acid 2:4,6:8-dianhydride (BODA) 4.50 g (0.018 mol) , 2.34 g (0.0054 mol) of the compound (PBCH5DAB) represented by the above formula (d-4-2) as a diamine and 1.92 g (0.0126 mol) of 3,5-diaminobenzoic acid (35DAB) in NMP26. After reacting in 3 g at room temperature, 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 wt% solution, and 2.4 g of acetic anhydride and 1.8 g of pyridine were added as an imidization catalyst to this, and the mixture was reacted at room temperature for 30 minutes and at 110° C. for 4 hours. Let 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-2)) was measured, it was 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 methyl 2-hydroxyisobutyrate (HBM) as the specific solvent (B). A solution having a polyimide concentration of 6.0% by weight was prepared. To this solution, 0.4 g of a 7.5 wt% NMP solution of 3-aminomethylpyridine (3-AMP) (corresponding to 0.03 g as 3-AMP) was added, and the mixture was stirred at 50° C. for 15 hours to give a liquid crystal. An aligning agent (S10A) was obtained. The liquid crystal aligning agent was prepared such that the solvent composition was NMP:D1:HBM=30:20:50 (weight ratio).

[Example 11A]
Same as 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. Moreover, the same operation as in 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 methyl 2-hydroxyisobutyrate (HBM) as the specific solvent (B). A solution having a polyimide concentration of 6.0% by weight was prepared. To this solution, 0.8 g of a 7.5 wt% 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 give a liquid crystal. An aligning agent (S11A) was obtained. The liquid crystal aligning agent was prepared such that the solvent composition was NMP:D2:HBM=30:30:40 (weight ratio).

[Example 12A]
A solution containing polyamic acid (PA-1) was prepared in the same manner as in 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 the first solvent and methyl 2-hydroxyisobutyrate (HBM) as the specific solvent (B) (D1:HBM=60). : 40 (weight ratio)) and a solid content concentration of 6.0% by weight to obtain a liquid crystal aligning agent (S12A).
[Example 13A]
A solution containing polyamic acid (PA-2) was prepared in the same manner as in 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 is dissolved in a mixed solvent of 3-butoxy-N,N-dimethylpropionamide (D2) as the first solvent and methyl 2-hydroxyisobutyrate (HBM) as the specific solvent (B) (D2:HBM=50). : 50 (weight ratio)) and a polyamic acid concentration of 6.0% by weight to obtain a liquid crystal aligning agent (S13A).

[Example 14A]
A solution containing polyamic acid (PA-3) was prepared in the same manner as in 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 the first solvent, and methyl 2-hydroxyisobutyrate (HBM) as the specific solvent (B) (NMP: A liquid crystal aligning agent (S14A) having a D1:HBM=40:40:20 (weight ratio) and a polyamic acid concentration of 6.0% by weight was obtained.
[Example 15A]
A solution containing polyamic acid (PA-4) was prepared in the same manner as in 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 the first solvent. (D2) and the specific solvent (B) are dissolved in a mixed solvent of methyl 2-hydroxyisobutyrate (HBM) (NMP:D2:HBM=40:40:20 (weight ratio)), and the polyamic acid concentration is 6.0. A liquid crystal aligning agent (S15A) in a weight percentage was obtained. The amount of the additive (E1) used was 5 parts by weight with respect to the polyamic acid powder.

[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 methyl 2-hydroxyisobutyrate (HBM) as the specific solvent (B) (D1:HBM=75). : 25 (weight ratio)), and a liquid crystal aligning agent (S16A) having a polyamic acid concentration of 6.0 wt% was obtained.
[Example 17A]
A solution containing polyamic acid (PA-6) was prepared in the same manner as in 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 is dissolved in a mixed solvent of 3-butoxy-N,N-dimethylpropionamide (D2) as the first solvent and methyl 2-hydroxyisobutyrate (HBM) as the specific solvent (B) (D2:HBM=35). : 65 (weight ratio)), and a liquid crystal aligning agent (S17A) having a polyamic acid concentration of 6.0 wt% was obtained.

[Example 18A]
A solution containing polyamic acid (PA-7) was prepared in the same manner as in 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 methyl 2-hydroxyisobutyrate (HBM) as the specific solvent (B) (NMP:D3:HBM=30:30). : 40 (weight ratio)), and a liquid crystal aligning agent (S18A) having a polyamic acid concentration of 6.0 wt% was obtained.
[Example 19A]
A solution containing the polyamic acid intermediate (PA-8) was prepared in the same manner as in 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 methyl 2-hydroxyisobutyrate (HBM) as the specific solvent (B) (NMP: A liquid crystal aligning agent (S19A) having a D2:HBM=30:30:40 (weight ratio) and a polyamic acid concentration of 6.0% by weight was obtained.
[Example 20A]
A polyimide (PI-1) powder was obtained in the same manner as in Example 9A. This powder was dissolved in a mixed solvent of 3-methoxy-N,N-dimethylpropionamide (D1) as the first solvent and methyl 2-hydroxyisobutyrate (HBM) as the specific solvent (B) (D1:HBM=50). : 50 (weight ratio)) and a solid content concentration of 6.0% by weight to obtain a liquid crystal aligning agent (S20A).

<Evaluation of storage stability>
Each of the liquid crystal aligning agents obtained above was filtered with a 1.0 μm filter, stored at −30° C. for 1 month, and then returned to room temperature (25° C.) to check for the presence of precipitates in the liquid crystal aligning agent. I observed. The results are shown in Tables 1 and 2 above. In Tables 1 and 2, the case where no precipitate was observed in the liquid crystal aligning agent was indicated by “◯”, and the case where the precipitate was observed was indicated by “x”.
<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.). Then, the liquid crystal aligning 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 aligning film printer (manufactured by Nissha Printing Co., Ltd.). Then, after heating (pre-baking) for 1 minute on a hot plate at 80°C to remove the solvent, heating (post-baking) for 10 minutes on a hot plate at 200°C formed a coating film having an average film thickness of 600Å. . The coating film was observed with a microscope at a magnification of 20 to check for print unevenness and pinholes. The evaluation was performed with good printability (◯) when almost no printing unevenness and pinholes were observed, and with poor printability (x) when at least one of printing 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-3:3,5-diaminocholestanyl benzoate 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)
HBM: Methyl 2-hydroxyisobutyrate BC: Butyl cellosolve (additive)
3-AMP: 3-aminomethylpyridine (compound represented by the above formula (c-1-16))

<Manufacturing and evaluation of photo-alignment FFS type liquid crystal display element>
(1) Manufacture of FFS type liquid crystal display element using photo-alignment method An FFS type liquid crystal display element 10 shown in FIG. 1 was manufactured. First, a bottom electrode 15 having no pattern, a silicon nitride film as an insulating layer 14, and a comb-shaped patterned top electrode 13 are formed in this order on a glass substrate 11a having an electrode pair on one side, and an electrode. And a counter glass substrate 11b not provided with the liquid crystal aligning agent (S1A) obtained above on one surface of the glass substrate 11a having the transparent electrode and one surface of the counter glass substrate 11b by an inkjet coating method. A coating film was formed. The liquid crystal aligning agent (S1A) was adjusted to have a viscosity of 18 cP with the solvent composition kept at “NMP:HBM=60:40 (weight ratio)” before being applied on the substrate, and the viscosity was adjusted. The liquid crystal aligning agent was applied onto the substrate.
Then, this 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 whose inside was replaced with nitrogen to obtain an average film thickness of 1,000Å. A coating film was formed. A schematic plan view of the top electrode 13 used here is shown in FIG. 2(a) is a top view of the top electrode 13, and FIG. 2(b) is an enlarged view of a portion C1 surrounded by a broken line in FIG. 2(a). In this example, a substrate having a top electrode having a line width d1 of the electrodes of 4 μm and a distance d2 between the electrodes of 6 μm was used. Further, as the top electrode 13, four-system drive electrodes of electrode A, electrode B, electrode C, and electrode D were used. FIG. 3 shows the structure of the drive electrodes of this liquid crystal display element. In this case, the bottom electrode 15 functions as a common electrode that acts on all the four-system drive electrodes, and each of the four-system drive electrode regions serves as a pixel region.

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

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 one of the substrates having the liquid crystal alignment film, and then the liquid crystal alignment film faces of the pair of substrates are applied. They were opposed to each other, and they were superposed and pressure-bonded so that the polarization planes of polarized ultraviolet rays were parallel to each other, and the adhesive was thermoset at 150° C. for 1 hour. Next, a liquid crystal “MLC-6221” manufactured by Merck Ltd. was filled into the gap between the substrates from the liquid crystal injection port, and then the liquid crystal injection port was sealed with an epoxy resin adhesive. Then, in order to remove the flow orientation at the time of liquid crystal injection, this was heated to 150° C. and then gradually cooled to room temperature.
Next, an FFS type liquid crystal display element was manufactured by bonding polarizing plates on both outer sides of the substrate. At this time, one of the polarizing plates was attached so that its polarization direction was parallel to the projection direction of the polarization plane of the polarized ultraviolet light of the liquid crystal alignment film onto the substrate surface, and the other one had the polarization direction first. It was attached so as to be orthogonal to the polarization direction of the polarizing plate.
The above method was repeated to manufacture a total of 5 FFS type liquid crystal display elements, and the FFS type liquid crystal display elements were subjected to the following evaluations of liquid crystal orientation, heat resistance, bezel unevenness, afterimage characteristics and contrast characteristics, respectively. However, in any case, the ultraviolet irradiation under the voltage application was not performed.

(2) Evaluation of liquid crystal orientation The FFS type liquid crystal display element manufactured above was observed with a microscope at a magnification of 50 times for the presence or absence of an abnormal domain in the change in light and dark when a voltage of 5 V was turned on/off (applied/released). did. The evaluation was performed when the liquid crystal alignment was “good” when no abnormal domain was observed, and as “poor” when the abnormal domain was observed. In this liquid crystal display element, the liquid crystal orientation was “good”.
(3) Evaluation of voltage holding ratio For 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) of was measured, the voltage holding ratio was 99.4%. As the measuring device, VHR-1 manufactured by Toyo Corp. 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 taken as the initial VHR (VHR _BF ). Next, the liquid crystal display element after the initial VHR measurement was left to stand in an oven at 100° C. for 500 hours. After that, this liquid crystal display device was allowed to stand at room temperature and allowed to cool to room temperature, and then the voltage holding ratio was measured in the same manner as above, and the value was taken as VHR _AF . In addition, the change rate (ΔVHR(%)) of the voltage holding ratio before and after applying the thermal stress was calculated by the following mathematical expression (EX-2).
ΔVHR (%)=((VHR _BF −VHR _AF )÷VHR _BF )×100 (EX-2)
The heat resistance was evaluated as follows: if the rate of change ΔVHR is less than 4%, the heat resistance is “good”, if 4% or more and less than 5%, the heat resistance is “OK”, and if it is 5% or more, the heat resistance is good. It was performed as "poor". As a result, ΔVHR was 2.9%, and the heat resistance of this liquid crystal display element was “good”.

(5) Mura resistance around the sealant (bezel mura resistance)
The FFS type liquid crystal display device manufactured 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 the lighting state. The evaluation is “excellent” if no brightness difference (more black or more white) is visually recognized around the sealant, but “good” if the brightness difference disappears within 5 minutes after lighting, 5 minutes If the brightness difference disappeared within 20 minutes, the result was “OK”, and if the brightness difference was visually recognized even after 20 minutes, the result was “poor”. As a result, the brightness difference of this liquid crystal display element was not visually recognized, and it was judged as “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 four drive electrodes, and the potential of the bottom electrode was set to 0V potential (ground potential). While the electrodes B and D were short-circuited to the common electrode and 0 V was applied, a composite voltage composed 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. Immediately after 2 hours, a voltage of AC 1.5 V was applied to all of the electrodes A to D. Then, from the time when a voltage of AC 1.5V is started to be applied to all drive electrodes, a drive stress application region (pixel regions of the electrodes A and C) and a drive stress non-application region (pixel regions of the electrodes B and D) are applied. The time until the difference in brightness from the above can no longer be visually confirmed was measured, and this was taken as the afterimage erasing time. It should be noted that the shorter this time is, the more difficult it is for an afterimage to occur. The case where the afterimage erasing time was less than 30 seconds was evaluated as “good”, the case of 30 seconds or more and less than 120 seconds was evaluated as “OK”, and the case of 120 seconds or more was evaluated as “poor”. The afterimage erasing time of the liquid crystal display element of No. 1 was 1 second, and the afterimage characteristic was evaluated as “good”.

<<Second Example>>
[Reference Example 1B]
A solution of polyamic acid (PA-1) was obtained by the same operation as in Example 1A above. To this polyamic acid solution, NMP and butyl glycolate (BGA) as a specific solvent (B) were added (NMP:BGA=60:40 (weight ratio)), and the liquid crystal was adjusted so that the polyamic acid concentration became 6.0% by weight. An aligning agent (S1B) was prepared.
[Reference Example 2B]
A solution of polyamic acid (PA-2) was obtained by the same operation as in Example 2A. To this NMP solution of polyamic acid (PA-2), NMP and butyl glycolate (BGA) as a specific solvent (B) were added (NMP:BGA=50:50 (weight ratio)), and the polyamic acid concentration was 6.0. The liquid crystal aligning agent (S2B) was prepared so as to be in a weight percentage.

[Reference Example 3B]
A solution of polyamic acid (PA-3) was obtained by the same operation as in Example 3A. To this NMP solution of polyamic acid (PA-3), NMP and butyl glycolate (BGA) as a specific solvent (B) were added (NMP:BGA=80:20 (weight ratio)), and the polyamic acid concentration was 6.0. A liquid crystal aligning agent (S3B) was prepared so that the weight percent was.
[Reference Example 4B]
A solution containing polyamic acid (PA-4) was obtained by the same operation as in Example 4A. The weight average molecular weight (Mw) of the obtained polyamic acid (PA-4) was 40,000. NMP and butyl glycolate (BGA) as a specific solvent (B) were added to 30 g of this solution (NMP:BGA=80:20 (weight ratio)) to prepare a liquid crystal aligning agent (S4B) having a concentration of 4.5% by weight. did.

[Reference Example 5B]
A solution containing polyamic acid (PA-5) was obtained by the same operation as in Reference Example 5A. Next, NMP and butyl glycolate (BGA) as a specific solvent (B) were added to 40.0 g of the obtained polyamic acid solution (NMP:BGA=75:25 (weight ratio)), and the polyamic acid concentration was 4.0 weight. The liquid crystal aligning agent (S5B) was prepared so that it would be %.
[Reference Example 6B]
A solution containing polyamic acid (PA-6) was obtained by the same operation as in Example 6A. Next, NMP and butyl glycolate (BGA) as a specific solvent (B) were added to the obtained NMP solution of polyamic acid (PA-6) (NMP:BGA=35:65 (weight ratio)) to obtain a solid content. The liquid crystal aligning agent (S6B) was prepared so that the concentration would be 3.0% by weight.

[Reference Example 7B]
A solution containing polyamic acid (PA-7) was prepared in the same manner as in Example 7A. To 25 g of this polyamic acid solution, NMP and butyl glycolate (BGA) as a specific solvent (B) were added (NMP:BGA=60:40 (weight ratio)) to obtain a solid content concentration of 5.0% by weight. A liquid crystal aligning agent (S7B) was prepared.
[Reference Example 8B]
A solution containing the polyamic acid intermediate (PA-8) was prepared by the same operation as in Example 8A. To the NMP solution of this polyamic acid intermediate, NMP and butyl glycolate (BGA) as a specific solvent (B) were added (NMP:BGA=60:40 (weight ratio)), and the solid content concentration was 6.0% by weight. A liquid crystal aligning agent (S8B) was prepared.

[Reference Example 9B]
White polyimide powder (polyimide (PI-1)) was obtained by the same operation as in Example 9A. To this powder, NMP and butyl glycolate (BGA) as a specific solvent (B) were added and dissolved (NMP:BGA=50:50 (weight ratio)), and a liquid crystal was prepared so that the solid content concentration became 4.5% by weight. An aligning agent (S9B) was prepared.
[Comparative Examples 1B to 9B]
Regarding the solvent composition of the liquid crystal aligning agent, the polymer was synthesized and the liquid crystal aligning agent was prepared in the same manner as in Reference Examples 1B to 9B except that butyl cellosolve (BC) was used as the second solvent instead of the specific solvent (B). The liquid crystal aligning agents (R1B) to (R9B) were respectively prepared. Note that Comparative Example XB (X is an integer of 1 to 9) is an example corresponding to Reference Example XB. That is, in Comparative Example XB, a liquid crystal aligning agent was prepared in the same manner as in Reference Example XB, except that the same polymer as in Reference Example XB was synthesized and butyl cellosolve was used instead of the specific solvent (B).

[Reference Example 10B]
White polyimide powder (polyimide (PI-2)) was obtained by the same operation as in Example 10A. 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 butyl glycolate (BGA) as the specific solvent (B) to obtain a polyimide concentration. It was a 6.0 wt% solution. To this solution, 0.4 g of a 7.5 wt% NMP solution of 3-aminomethylpyridine (3-AMP) (corresponding to 0.03 g as 3-AMP) was added, and the mixture was stirred at 50° C. for 15 hours to give a liquid crystal. An aligning agent (S10B) was obtained. The liquid crystal aligning agent was prepared such that the solvent composition of the liquid crystal aligning agent was NMP:D1:BGA=30:20:50 (weight ratio).

[Reference Example 11B]
A polyimide powder (polyimide (PI-3)) was obtained by performing the same operation as in Example 11A. 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 butyl glycolate (BGA) as the specific solvent (B) to obtain a polyimide concentration. It was a 6.0 wt% solution. To this solution, 0.8 g of a 7.5 wt% 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 give a liquid crystal. An aligning agent (S11B) was obtained. The liquid crystal aligning agent was prepared so that the solvent composition of the liquid crystal aligning agent was NMP:D2:BGA=30:30:40 (weight ratio).

[Reference Example 12B]
A solution containing polyamic acid (PA-1) was prepared in the same manner as in 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 the first solvent and butyl glycolate (BGA) as the specific solvent (B) (D1:BGA=60:40( 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 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 butyl glycolate (BGA) as the specific solvent (B) (D2:BGA=50:50( A weight ratio)) and a liquid crystal aligning agent (S13B) having a polyamic acid concentration of 6.0% by weight were obtained.

[Reference Example 14B]
A solution containing polyamic acid (PA-3) was prepared in the same manner as in 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 the first solvent and butyl glycolate (BGA) as the specific solvent (B) (NMP:D1:BGA =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 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 the first solvent. (D2) and a specific solvent (B) dissolved in a mixed solvent of butyl glycolate (BGA) (NMP:D2:BGA=40:40:20 (weight ratio)), and a polyamic acid concentration of 6.0% by weight. A liquid crystal aligning agent (S15B) was obtained. The amount of the additive (E1) used was 5 parts by weight with respect to the polyamic acid powder.

[Reference Example 16B]
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 butyl glycolate (BGA) as the specific solvent (B) (D1:BGA=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 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 butyl glycolate (BGA) as the specific solvent (B) (D2:BGA=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 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 butyl glycolate (BGA) as the specific solvent (B) (NMP:D3:BGA=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 the polyamic acid intermediate (PA-8) was prepared in the same manner as in 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 butyl glycolate (BGA) as the specific solvent (B) (NMP:D2:BGA). = 30:30:40 (weight ratio)), and a liquid crystal aligning agent (S19B) having a polyamic acid concentration of 6.0% by weight was obtained.
[Reference Example 20B]
A polyimide (PI-1) powder was obtained in the same manner as in Example 9A. This powder was dissolved in a mixed solvent of 3-methoxy-N,N-dimethylpropionamide (D1) as the first solvent and butyl glycolate (BGA) as the specific solvent (B) (D1:BGA=50:50( A liquid crystal aligning agent (S20B) having a solid content concentration of 6.0% by weight was obtained.

<Evaluation of storage stability>
For each liquid crystal aligning agent obtained above, the presence or absence of precipitates in the liquid crystal aligning agent was observed by the same method as in Example 1A. The results are shown in Tables 3 and 4 below. In Tables 3 and 4, as in Tables 1 and 2, the case where no precipitate was observed in the liquid crystal aligning agent was indicated by “◯”, and the case where the precipitate was observed was indicated by “x”.
<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.). Then, the liquid crystal aligning 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 aligning film printer (manufactured by Nissha Printing Co., Ltd.). Then, after heating (pre-baking) for 1 minute on a hot plate at 80°C to remove the solvent, heating (post-baking) for 10 minutes on a hot plate at 200°C formed a coating film having an average film thickness of 600Å. . The coating film was observed with a microscope at a magnification of 20 to check for print unevenness and pinholes. The evaluation was performed with good printability (◯) when almost no printing unevenness and pinholes were observed, and with poor printability (x) when at least one of printing unevenness and pinholes was observed. The results are shown in Tables 3 and 4 below.

The abbreviations in Tables 3 and 4 are the same as those in Tables 1 and 2 above.

<Manufacturing and evaluation of photo-alignment FFS type liquid crystal display element>
(1) Manufacture of FFS type liquid crystal display element using photo-alignment method The same operation as in Example 1A above was carried out except that the liquid crystal aligning agent used was changed from (S1A) to (S1B), and shown in FIG. The FFS type liquid crystal display element 10 was produced.
(2) Evaluation of liquid crystal orientation The liquid crystal orientation of the FFS type liquid crystal display element produced above was evaluated in the same manner as in Example 1A. As a result, in this liquid crystal display element, the liquid crystal orientation was “good”.
(3) Evaluation of voltage holding ratio With respect to the FFS type liquid crystal display element manufactured as described above, the voltage holding ratio was evaluated in the same manner as in Example 1A. In this example, the voltage holding ratio was 99.4%.
(4) Evaluation of heat resistance The FFS type liquid crystal display element produced above was evaluated for heat resistance in the same manner as in Example 1A. As a result, ΔVHR was 2.9%, and the heat resistance of this liquid crystal display element was “good”.

(5) Mura resistance around the sealant (bezel mura resistance)
The bezel unevenness resistance of the FFS type liquid crystal display element manufactured as described above was evaluated in the same manner as in Example 1A. As a result, the brightness difference of this liquid crystal display element was not visually recognized, and it was judged as “excellent”.
(6) Evaluation of afterimage characteristics (DC afterimage evaluation)
DC afterimage evaluation was performed in the same manner as in Example 1A except that the photo-alignment type liquid crystal display element produced above was used. As a result, the afterimage erasing time of the liquid crystal display element of this example was 1 second, and the afterimage characteristic was evaluated as “good”.

As shown in Tables 1 to 4, all the liquid crystal aligning agents of the examples using the specific solvent (B) have good storage stability when stored at low temperature, and also have printability after low temperature storage. It was good. On the other hand, the liquid crystal aligning agent of Comparative Example had poor storage stability and printability after storage at low temperature. From this, it was found that the use of the specific solvent (B) can improve the storage stability while ensuring the coating property on the substrate. Further, in the liquid crystal display device using the liquid crystal aligning agent containing the specific solvent (B), the unevenness around the sealant is not visually recognized, and the bezel unevenness resistance is judged to be “excellent”, and the liquid crystal aligning agent capable of achieving a narrow frame can be achieved. The result suggesting that On the other hand, in the liquid crystal display element using the liquid crystal aligning agent of the comparative example not containing the specific solvent (B), the unevenness disappeared, but the unevenness was visually recognized. Thus, it was shown that the liquid crystal alignment film using the liquid crystal alignment agent containing the specific solvent (B) is suitable for providing a liquid crystal display device corresponding to a narrow frame.

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 (5)

A liquid crystal aligning agent containing a solvent, and at least one polymer (A) selected from the group consisting of a polyamic acid obtained by reacting a tetracarboxylic dianhydride and a diamine, a polyimide, and a polyamic acid ester. hand,
The solvent contains a compound represented by the following formula (b-1A) as a specific solvent (B),
The polymer (A) is a polymer obtained using a diamine containing at least one selected from the group consisting of compounds represented by the following formulas (d-1) to (d-4), Liquid crystal aligning agent.

(In formula (b-1A), R ^{8 to} R ¹⁰ are each independently a methyl group or an ethyl group.)

(In 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. And R ¹ and R ² are each independently an alkanediyl group having 1 to 3 carbon atoms, n1 is 0 or 1, and n2 and n3 satisfy n2+n3=2 when n1=0. It is an integer, and when n1=1, n2=n3=1 In the formula (d-2), X ³ is —O—, m1 is an integer of 0 to 3, and m2 is m1=. When it is 0, it is an integer of 1 to 12, and when m1 is an integer of 1 to 3, it is m2 = 2. In the formula (d-3), R ³ is a monovalent carbon having 1 to 12 carbons. Is a hydrogen group, R ⁴ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms, and R ⁵ and R ⁶ are each independently a hydrogen atom or a methyl group. -4), X ⁴ and X ⁵ are each independently a single bond, -O-, -COO- or -OCO-, R ⁷ is an alkanediyl group having 1 to 3 carbon atoms, and ⁴ is a single bond or an alkanediyl group having 1 to 3 carbon atoms, a is 0 or 1, b is an integer of 0 to 2, c is an integer of 1 to 20, k is 0 or 1. However, a and b cannot be 0 at the same time.) The liquid crystal aligning agent according to claim 1, wherein the content of the specific solvent (B) is 1 to 70% by weight of the total amount of the solvent. The polymer (A) is a compound represented by the following formula (t-1), 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride. And the liquid crystal aligning agent according to claim 1, which is a polymer obtained by using a tetracarboxylic dianhydride containing at least one selected from the group consisting of 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 having one primary amino group and a nitrogen-containing aromatic heterocycle in the molecule, and the primary amino group bonded to a chain hydrocarbon group or an alicyclic hydrocarbon group (C ) Is further contained, The liquid crystal aligning agent of any one of Claims 1-3. The liquid crystal aligning agent according to claim 4, wherein the amine compound (C) is a compound represented by the following formula (c-1).

(In 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. The primary amino group in the formula is bonded to the chain hydrocarbon group or alicyclic hydrocarbon group which A ¹ has.)

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