JP6557963B2 - Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element - Google Patents

Description

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

  Conventionally, as a liquid crystal display element, various drive types having different electrode structures and 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 from the viewpoints of 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 the 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, in order to improve the applicability (printability) of the liquid crystal aligning agent when the liquid crystal aligning agent is applied to the substrate together with a good solvent such as polyamic acid, for example, butyl cellosolve, etc. Such a poor solvent having a relatively low surface tension is used together (for example, see Patent Document 1 and Patent Document 2).

JP 2010-97188 A JP 2010-156934 A

  The liquid crystal aligning agent is usually stored in a cryogenic environment (for example, at −15 ° C.) in order to prevent deterioration of the polyamic acid and the polyimide from production to shipment. However, in the liquid crystal aligning agent stored at a low temperature for a long time, precipitates may be generated in the solution. In addition, the precipitate once deposited is difficult to be re-dissolved, and may cause problems such as defective printing in the manufacturing process of the liquid crystal display element. The cause of the occurrence of such precipitates is not clear, but it is assumed that butyl cellosolve, which is generally used as a solvent component of the liquid crystal aligning agent, is one cause. Therefore, it is required to find a new organic solvent that replaces butyl cellosolve as a solvent for improving the coating property to the substrate.

  A liquid crystal display is manufactured by disposing a pair of substrates on which a liquid crystal alignment film is formed facing each other and disposing a liquid crystal between the pair of facing substrates. In that case, a pair of board | substrates are bonded together using sealing agents, such as an epoxy resin. Here, in touch panel type display panels represented by smartphones and tablet PCs, attempts have been made to narrow the frame in order to achieve a wider movable area of the touch panel and a reduction in the size of the liquid crystal panel (element). ing. With the narrowing of the frame of the liquid crystal panel, display unevenness may be visually recognized around the sealing agent, which is not fully satisfactory in terms of display quality. In order to increase the definition and life of the liquid crystal display, a liquid crystal display element is required in which display unevenness around such a sealant is hardly visible (high bezel unevenness resistance).

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a liquid crystal aligning agent that has good storage stability for low-temperature storage for a long period of time and good applicability to a substrate, and is compatible with narrowing the frame. And

  As a result of intensive investigations to achieve the above-described problems of the prior art, the present inventors have found that a specific solvent is used as at least a part of the solvent component in the liquid crystal aligning agent containing polyimide or a precursor thereof as the polymer component. It has been found that the above-mentioned problems can be solved by using it, and the present invention has been completed. Specifically, the present invention provides the following liquid crystal aligning agent, liquid crystal alignment film, and liquid crystal display element.

  In the first aspect, the present invention provides at least one polymer (A) selected from the group consisting of polyamic acid, polyimide and polyamic acid ester obtained by reacting tetracarboxylic dianhydride and diamine, and a solvent. And the solvent is at least one selected from the group consisting of a compound represented by the following formula (b-1A) and a compound represented by the following formula (b-1B). A liquid crystal aligning agent containing the specific solvent (B) 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 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 formula (b-1B), R ⁸ , R ⁹ and R ¹¹ are each independently a monovalent hydrocarbon group or hydrogen atom having 1 to 5 carbon atoms, and X is an OH group or an SH group. , N is 0 or 1.)

  In the second aspect of the present invention, the polymer (A) is a diamine containing at least one selected from the group consisting of compounds represented by the following formulas (d-1) to (d-5). Provided is a liquid crystal aligning agent comprising a polymer obtained by use.

（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. 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. When n1 = 1, n2 = n3 = 1 In 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 from 1 to 12 in the case of m1 = 0, in m1 is m @ 2 = 2 in the case of an integer from 1 to 3. formula ^{(d-3), R} 3 has a carbon number is R ⁴ is a monovalent hydrocarbon group having 1 to 12 carbon atoms, 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 monovalent hydrocarbon group. In the formula (d-4), X ⁴ and X ⁵ are each independently a single bond, —O—, —COO— or —OCO—, and R ⁷ is a hydrogen atom or a methyl group. , An alkanediyl group having 1 to 3 carbon atoms, 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 an integer of 1 to 20, and k is 0 or 1. However, a and b are not simultaneously 0. In formula (d-5), A ¹ is a single bond, having 1 to 1 carbon atoms. 12 an alkanediyl group or a fluoroalkanediyl group having 1 to 6 carbon atoms, A ² represents —O—, —COO—, —OCO—, —NHCO—, —CONH— or —CO—, and A ³ Represents a monovalent organic group having a steroid skeleton.)

  When the above-mentioned specific solvent (B) is included as a solvent component of the liquid crystal aligning agent, precipitates are not easily generated in the aligning agent even when stored in a low temperature environment for a long time, and the storage stability is good. is there. Moreover, the applicability | paintability with respect to the board | substrate of a liquid crystal aligning agent is also favorable. Furthermore, a liquid crystal display element showing good display quality can be obtained even if the liquid crystal display element is narrowed. In addition, when at least a part of the polymer component is a polymer (A) obtained using the above-mentioned specific diamine, the above effect is high and suitable.

  In the third 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. B), the additive has one primary amino group and a nitrogen-containing aromatic heterocyclic ring in the molecule, 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 the liquid crystal aligning agent containing the polymer (A) as at least a part of the polymer component, when the amine compound (C) is included as an additive, the liquid crystal aligning agent is stored in a low temperature environment for a long time. In such a case, the amine compound (C) may be precipitated in the alignment agent. In this regard, according to the liquid crystal aligning agent of the third aspect of the present invention, the above-mentioned specific solvent (B) is included as a solvent component, so that it can be contained in the aligning agent even when stored in a low temperature environment for a long time. Precipitates are not easily generated and storage stability is good. Moreover, the applicability | paintability with respect to the board | substrate of a liquid crystal aligning agent is also favorable.

  In the fourth aspect of the present invention, the liquid crystal alignment film formed of the liquid crystal aligning agent of the first side, the liquid crystal aligning agent of the second side, or the liquid crystal aligning agent of the third side, and the liquid crystal alignment film A liquid crystal display device comprising: Since the liquid crystal aligning film of this invention is formed using the said liquid crystal aligning agent, when a liquid crystal aligning agent is stored for a long time in a low-temperature environment, applicability | paintability (printability) is favorable. Further, when a liquid crystal display element 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. The plane schematic diagram of the top electrode used for manufacture of the liquid crystal display element by a photo-alignment method. (A) is a top view of a top electrode, (b) is the elements on larger scale of a top electrode. The figure which shows the drive electrode of 4 systems. The plane schematic diagram of the top electrode used for manufacture of the liquid crystal display element by a rubbing process. (A) is a top view of a top electrode, (b) is the elements on larger scale of a top electrode.

  The liquid crystal aligning agent which concerns on this invention contains at least 1 type of polymer (A) chosen from the group which consists of a polyamic acid, a polyimide, and a polyamic acid ester as a polymer component, and the said polymer (A) serves 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 this invention can be obtained by making tetracarboxylic dianhydride and diamine react.

（式（ｔ−１）中、Ｘ^７、Ｘ^８、Ｘ^９及びＸ^１０は、それぞれ独立に、単結合又はメチレン基であり、ｊは１〜３の整数である。）
で表される化合物などを；
芳香族テトラカルボン酸二無水物として、例えばピロメリット酸二無水物などを；それぞれ挙げることができるほか、特開２０１０−９７１８８号公報に記載のテトラカルボン酸二無水物を用いることができる。なお、テトラカルボン酸二無水物は、上記のものを１種単独で又は２種以上組み合わせて使用することができる。 [Tetracarboxylic dianhydride]
Examples of the tetracarboxylic dianhydride used for the synthesis of the polyamic acid include an aliphatic tetracarboxylic dianhydride, an alicyclic tetracarboxylic dianhydride, and an aromatic tetracarboxylic dianhydride. Specific examples of these are:
Examples of the aliphatic tetracarboxylic dianhydride include 1,2,3,4-butanetetracarboxylic dianhydride;
Examples of the alicyclic tetracarboxylic dianhydride include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 1,3,3a, 4, 5,9b-Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b- Hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 3-oxabicyclo [3.2.1] octane -2,4-dione-6-spiro-3 '-(tetrahydrofuran-2', 5'-dione), 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene- No 1,2-dicarboxylic acid Things, 3,5,6-tricarboxy-2-carboxymethyl norbornane -2: 3,5: 6-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^{2, 6]} undecane -3,5,8,10-tetraone, cyclohexanetetracarboxylic dianhydride, the following formula (t-1)

(In 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 dianhydride include pyromellitic dianhydride and the like; respectively, and tetracarboxylic dianhydrides described in JP 2010-97188 A can be used. In addition, tetracarboxylic dianhydride can use the said thing individually by 1 type or in combination of 2 or more types.

  Here, examples of the compound represented by the above formula (t-1) include bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic dianhydride and 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 formula (t-1), bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic dianhydride is particularly preferable from the viewpoint of stability of liquid crystal alignment. Is preferred.

  Among the tetracarboxylic dianhydrides used for the synthesis of polyamic acid, among the above, the compound represented by the above formula (t-1), 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 1,2 , 3,4-cyclobutanetetracarboxylic dianhydride and pyromellitic dianhydride, it is preferable to use at least one compound selected from the group consisting of pyromellitic dianhydride (hereinafter also referred to as specific tetracarboxylic dianhydride). . When the specific tetracarboxylic dianhydride is used, the total amount of the specific tetracarboxylic dianhydride is 10 mol% or more with respect to the total amount of tetracarboxylic dianhydride used for the synthesis of the polyamic acid. It is preferable that it is 20-100 mol%.

[Diamine]
As a diamine used for the synthesis of polyamic acid, a compound represented by the above formula (d-1), a compound represented by the above formula (d-2), a compound represented by the above formula (d-3), It contains at least one diamine 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) (hereinafter also referred to as “specific diamine”). Is preferred.

(Compound represented by Formula (d-1))
In the formula (d-1), examples of the alkanediyl group having 1 to 3 carbon atoms of R ¹ and R ² include a methylene group, an ethylene group, a propane-1,2-diyl group, and propane-1,3-diyl. Group, 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 a single bond, —O—, —S—, —OCO— or —COO—. X ¹ and X ² may be the same or different. Among these, a single bond, —O—, or —S— is preferable.
Y ¹ is an oxygen atom or a sulfur atom. Preferably, it is an oxygen atom.

Two primary amino groups of the compound represented by formula (d-1) may be bonded to the same benzene ring when n1 = 0, or may be bonded to two different benzene rings one by one. It may be. On the other hand, when n1 = 1, two primary amino groups are bonded to different benzene rings one by one.
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 other groups, and 3-position or 4-position. And is more preferably 4-position. In addition, when there are two primary amino groups on the benzene ring, the bonding position may be, for example, 2,4-position, 2,5-position, etc. with respect to other groups. Is preferred.
The hydrogen atom on the benzene ring to which the primary amino group is bonded is a monovalent hydrocarbon group having 1 to 10 carbon atoms or a monovalent 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 and the like), aralkyl groups having 5 to 10 carbon atoms (benzyl group and the like), and the like.

  In the present specification, the “hydrocarbon group” means a chain hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. Further, the “chain hydrocarbon group” means a linear hydrocarbon group and a branched hydrocarbon group which are composed only of a chain structure without including a cyclic structure in the main chain. The chain structure may be saturated or unsaturated. The “alicyclic hydrocarbon group” means a hydrocarbon group that includes only an alicyclic hydrocarbon structure as a ring structure and does not include an aromatic ring structure. However, it is not necessary to be comprised only by the structure of an alicyclic hydrocarbon, The thing which has a chain structure in the part is also included. “Aromatic hydrocarbon group” means a hydrocarbon group containing an aromatic ring structure as a ring structure. However, it is not necessary to be composed only of an aromatic ring structure, and a part thereof may include a chain structure or an alicyclic hydrocarbon structure.

  Preferable specific examples of the compound represented by the formula (d-1) include, for example, 4,4′-diaminodiphenylamine, 2,4-diaminodiphenylamine and the like as the compound where n1 = 0; 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- Mino benzoyloxy) ethyl) urea, 1,3-bis (3- (2-amino-benzoyloxy) propyl) urea or the like; may be mentioned, respectively. 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—, and 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, m1 = 0 is preferable from the viewpoint of improving the rubbing resistance while maintaining good liquid crystal orientation, and m1 is an integer of 1 to 3 from the viewpoint of reducing the pretilt angle of the liquid crystal molecules. 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 in the 3-position or 4-position with respect to the other group, and more preferably in the 4-position. The hydrogen atom on the benzene ring to which the primary amino group is bonded is a monovalent hydrocarbon group having 1 to 10 carbon atoms or a 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.

  Preferable specific examples of the compound represented by the 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-aminopheny) ) Heptane, bis (4-aminophenyl) octane, bis (4-aminophenyl) nonane, bis (4-aminophenyl) decane, 1,3-bis (4-aminophenylsulfanyl) propane, 1,4-bis ( 4-aminophenylsulfanyl) butane and the like. In addition, as a compound represented by the said Formula (d-2), these exemplary compounds can be used individually by 1 type or in mixture of 2 or more types.

(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, for example, methyl groups, ethyl groups, propyl groups, isopropyl groups, butyl groups, isobutyl groups, t-butyl groups, pentyl groups, hexyl groups, octyl groups, decyl groups and other alkyl groups; vinyl groups Alkenyl groups such as allyl group; cycloalkyl groups such as cyclopentyl group and cyclohexyl group; aryl groups such as phenyl group and tolyl group; aralkyl groups such as benzyl group and the like. R ³ preferably has 1 to 6 carbon atoms, more preferably 1 to ³ carbon atoms. R ³ is preferably a chain hydrocarbon group, more preferably a chain hydrocarbon group containing a carbon-carbon double bond, and still more preferably an alkenyl group.

R ⁴ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms. Examples of the hydrocarbon group include a chain hydrocarbon group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and an aromatic hydrocarbon group having 5 to 12 carbon atoms. specific examples thereof include the groups exemplified in the description of the R ^3. R ⁴ is preferably a hydrogen atom or a chain hydrocarbon group having 1 to 12 carbon atoms. Further, the hydrocarbon group for R ⁴ is preferably from 1 to 6 carbon atoms, and more preferably 1 to 3 carbon atoms.
R ⁵ and R ⁶ are each independently a hydrogen atom or a methyl group, and preferably both are hydrogen atoms.
In the diaminophenyl group of the above formula (d-3), the bonding position of the two primary amino groups is not particularly limited, but the 2,4-position or 2 with respect to the group having an N-allyl structure bonded to the benzene ring. , 5-position is preferred, and 2,4-position is more preferred. The hydrogen atom on the benzene ring to which the primary amino group is bonded is a monovalent hydrocarbon group having 1 to 10 carbon atoms or a monovalent 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.

Preferable specific 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, the following formula (d -3-1) to (d-3-3), and the like.

(Compound represented by formula (d-4))
In the formula (d-4), examples of the divalent group represented by “—X ⁴ — (R ⁷ —X ⁵ ) _k —” include alkanediyl groups having 1 to 3 carbon atoms, * —O—, * It is preferably —COO— or * —O—C ₂ H ₄ —O— (where a bond marked with “*” is bonded to a diaminophenyl group).
The group “—C _c H _{2c + 1} ” is preferably linear, and specific examples thereof include, for example, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, and an n-hexyl group. 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 in the 2,4-position or 3,5-position, more preferably in the 2,4-position, with respect to the group “X ⁴ ”. 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.

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

(Compound represented by Formula (d-5))
In the 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 represents —O—, —COO—, —OCO. -, - NHCO -, - CONH- or -CO- indicates, ^{a 3} represents a monovalent organic group having a steroid skeleton.
The alkanediyl group having 1 to 12 carbon atoms in ^{A 1} of the formula (d-5), preferably alkanediyl group having 1 to 4 carbon atoms, a methylene group, an ethylene group, 1,3-propanediyl, 1 More preferred is a 4-butanediyl group. The fluoro alkanediyl group having 1 to 6 carbon atoms, preferably perfluoro alkanediyl group having 1 to 4 carbon atoms, -CF ₂ -, perfluoro ethylene group, 1,3-perfluoro-propanediyl, 1,4 -A perfluorobutanediyl group is more preferred.
A ² is preferably —O—.
The steroid skeleton in A ³ refers to a structure composed of a cyclopentano-perhydrophenanthrene nucleus or a structure in which one or more of its carbon-carbon bonds are double bonds. As the monovalent organic group having such a steroid skeleton, those having 17 to 40 carbon atoms are preferable.

  Preferable specific examples of the compound represented by the above formula (d-5) include 1-cholesteryloxymethyl-2,4-diaminobenzene, 1-cholesteryloxymethyl-3, 5-diaminobenzene, 1- (1-cholesteryloxy-1,1-difluoromethyl) -2,4-diaminobenzene, 1- (1-cholesteryloxy-1,1-difluoromethyl) -3,5- Diaminobenzene, 1- (1-cholestanioxy-1,1-difluoromethyl) -2,4-diaminobenzene, 1- (1-cholestanioxy-1,1-difluoromethyl) -3,5-diaminobenzene 3- (2,4-diaminophenylmethoxy) -4,4-dimethylcholestane, 3- (1- (2,4-diaminophenyl) -1,1-difluoromethoxy)- , 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) chorane- 24-acid hexadecyl, 3-((3,5-diaminophenyl) methoxy) cholan-24-acid hexadecyl, 3- (1- (3,5-diaminophenyl) -1,1-difluoromethoxy) chorane-24 Acid hexadecyl, 3- (2,4-diaminophenylmethoxy) chorane-24-acid stearyl, 3- (1- (2,4-diaminophenyl) -1,1-diph Olomethoxy) cholan-24-acid stearyl, 3- (3,5-diaminophenylmethoxy) chorane-24-acid stearyl, 3- (1- (3,5-diaminophenyl) -1,1-difluoromethoxy) chorane- 24-acid stearyl, 1-cholesteryloxy-2,4-diaminobenzene, cholesteryl 3,5-diaminobenzoate, 1-cholestanioxy-2,4-diaminobenzene and cholestanyl 3,5-diaminobenzoate It is preferable to use one or more selected from the group, and among these, 1-cholesteryloxy-2,4-diaminobenzene, 3,5- Cholesteryl diaminobenzoate, 1-cholestanioxy-2,4-diaminobenzene and 3,5-diamino It is particularly preferred to use at least one selected from the group consisting of Ikikosan cholestanyl.

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

(Other diamines)
As the diamine used for the synthesis of the polyamic acid, a compound other than the specific diamine (other 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, and 1,3-bis (aminomethyl) cyclohexane. Alicyclic diamines such as 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-phenylenediisopropylene Riden) bisaniline, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diamino Pyrimidine, 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-aminophen ) -2,3-dihydro-1,3,3-trimethyl-1H-indene-6-amine, 4- (4′-trifluoromethoxybenzoyloxy) cyclohexyl-3,5-diaminobenzoate, 4- ( 4′-trifluoromethylbenzoyloxy) cyclohexyl-3,5-diaminobenzoate, 1,1-bis (4-((aminophenyl) methyl) phenyl) -4-butylcyclohexane, 1,1-bis (4- ((Aminophenyl) methyl) phenyl) -4-heptylcyclohexane, 1,1-bis (4-((aminophenoxy) methyl) phenyl) -4-heptylcyclohexane, 1,1-bis (4-((aminophenyl) ) Methyl) phenyl) -4- (4-heptylcyclohexyl) cyclohexane, 4-aminobenzylamine, 3-aminoben Such as zilamine, 2,2-bis [4- (4-aminophenoxy) phenyl] propane;
Examples of the diaminoorganosiloxane include 1,3-bis (3-aminopropyl) -tetramethyldisiloxane, and the like, and diamines described in JP 2010-97188 A can be used. In addition, these other diamine 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 preferably contains a diamine (hereinafter also referred to as “carboxyl group-containing diamine”). The carboxyl group-containing diamine is preferably an aromatic diamine, and specific examples include compounds represented by the following formulas (e1-1) and (e1-2).

(In 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, 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, provided that r3 + r5 + r7 ≦ 5 and r4 + r6 + r8 ≦ 5, in the case where a plurality of R ²⁰ are present, 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. , An octyl group, a nonyl group, a 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, and a prepylene group.
r1, r3 and r4 are preferably 0 or 1, 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. As a compound represented by the following formula (e1-2), for example, 4,4′-diaminobiphenyl-3,3′-dicarboxylic acid, 4,4′-diaminobiphenyl-2,2′-dicarboxylic acid, 3, 3'-diaminobiphenyl-4,4'-dicarboxylic acid, 3,3'-diaminobiphenyl-2,4'-dicarboxylic acid, 4,4'-diaminodiphenylmethane-3,3'-dicarboxylic acid, 4,4 ' -Diaminobiphenyl-3-carboxylic acid, 4,4'-diaminodiphenylmethane-3-carboxylic acid, 4,4'-diaminodiphenylethane-3,3'-dicarboxylic acid, 4,4 ' It can be mentioned; diaminodiphenyl ethane-3-carboxylic acid, 4,4'-diaminodiphenyl ether 3,3'-dicarboxylic acid, 4,4'-like diaminodiphenyl ether 3-carboxylic acid.

The usage-amount of the specific diamine at the time of synthesize | combining a polyamic acid can be arbitrarily set according to the compound to be used. For example, when using the compound represented by the formula (d-1), the amount used is preferably 10 mol% or more, more preferably 30 mol% or more, based on the total diamine. . Moreover, when using the compound represented by the said Formula (d-2), from the viewpoint of providing a low inclination-alignment angle with respect to a liquid crystal molecule, the usage-amount is 10 mol% or more with respect to all the diamines. Preferably, it is more preferably 30 mol% or more, and still more preferably 50 mol% or more.
When using the compound represented by the formula (d-3), the amount used is preferably 5 mol% or more based on the total diamine from the viewpoint of improving the stability of the voltage holding ratio. More preferably, it is 10 mol% or more.

In the case of using at least one selected from the group consisting of the compound represented by the above formula (d-4) and the compound represented by the above formula (d-5), from the viewpoint of imparting good orientation, the use thereof The amount (the total amount when two or more compounds are used) is preferably 5 mol% or more, more preferably 10 mol% or more, based on the total diamine. In addition, as specific diamine, 1 type in the compound illustrated above can be used individually or in combination of 2 or more types.
When a carboxyl group-containing diamine is used as the other diamine, the use ratio thereof is preferably 5 mol% or more, more preferably 10 to 90 mol%, more preferably 10 mol% to the total diamine. -70 mol% is still more preferable.

（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 element, in the synthesis of the polyamic acid in the present invention, 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 having 6 to 20 carbon atoms or an alkoxy group, 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 of R ²³ include hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tridecyl, tetradecyl, and pentadecyl. A hexadecyl group, a heptadecyl group, an octadecyl group, a nonadecyl group, an eicosyl group, and the like, which may be linear or branched. As a C6-C20 alkoxy group, group (-OR < ²³ >) etc. which the C6-C20 alkyl group of the said illustration couple | bonded with the oxygen atom are mentioned, for example.

Examples of the divalent organic group in R ²⁴ include divalent hydrocarbon groups 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. Among them, a group having a functional group such as -O-, -CO-, -COO-, -S-, a heterocyclic group and the like can be mentioned. Here, specific examples of the divalent hydrocarbon group include a chain hydrocarbon group such as methylene group, ethylene group, propanediyl group, butanediyl group, pentanediyl group, hexanediyl group, heptanediyl group, octanediyl group, Nonanediyl group, decanediyl group, undecanediyl group, dodecanediyl group, tridecanediyl group, tetradecanediyl group, pentadecanediyl group, octadecanediyl group, icosylene group, vinylene group, propenediyl group, butenediyl group, pentenediyl group, ethynylene group, propynylene group An alicyclic hydrocarbon group such as cyclopropylene group, cyclobutylene group, cyclopentylene group, cyclohexylene group, cyclohexenylene group, cycloheptylene group, cyclooctylene group, cyclononylene group, cyclodeoxy group, etc. Len group, cycloundecylene group, cyclododecylene group, cyclotridecylene group, cyclotetradecylene group, cyclopentadecylene group, cyclooctadecylene group, cycloicosylene group, bicyclohexylene group, norbornylene group, adamantylene group, etc. Examples of the aromatic hydrocarbon group 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.

  Preferable specific examples of the monoamine represented by the 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;

From the viewpoint of suppressing the monoamine liberated in the produced liquid crystal cell from adversely affecting the display characteristics, the monoamine is used in a mole of tetracarboxylic dianhydride, b mole of diamine, and c of monoamine. It is preferable to satisfy “2 (ab) ≧ c> 0” in the case of mol.
The monoamine represented by the above formula (m-1) may be reacted and polymerized with respect to the reaction product after the reaction between tetracarboxylic dianhydride and diamine, or the tetracarboxylic dianhydride. The three components of anhydride, diamine and monoamine may be reacted and polymerized simultaneously.

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

Examples of molecular weight regulators include acid monoanhydrides, monoamine compounds, and monoisocyanate compounds. Specific examples thereof include acid monoanhydrides such as maleic anhydride, phthalic anhydride, itaconic anhydride, n-decylsuccinic anhydride, n-dodecylsuccinic anhydride, n-tetradecylsuccinic. Acid anhydride, n-hexadecyl succinic anhydride, etc .; monoamine compounds such as aniline, cyclohexylamine, n-butylamine, compounds represented by the above formula (m-1), etc .; monoisocyanate compounds; Examples thereof include phenyl isocyanate and naphthyl isocyanate.
The use ratio of the molecular weight regulator is preferably 20 parts by weight or less, and more preferably 10 parts by weight or less with respect to 100 parts by weight of the total of the tetracarboxylic dianhydride and diamine used.

<Synthesis of polyamic acid>
The ratio of the tetracarboxylic dianhydride and the diamine used in the polyamic acid synthesis reaction is 0.2 to 2 for the tetracarboxylic dianhydride acid anhydride group to 1 equivalent of the amino group of the diamine. The ratio which becomes an equivalent is preferable, and the ratio which becomes 0.3-1.2 equivalent is more preferable.
The polyamic acid synthesis reaction 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, phenol solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons, hydrocarbons, and the like.
Specific examples of these organic solvents include, for example, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, N-ethyl-2-pyrrolidone, N, N as the aprotic polar solvent. -Dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide and the like; as the phenol solvent, for example, phenol, m-cresol, xylenol, halogenated phenol, etc. ;

Examples of the alcohol include methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, ethylene glycol monomethyl ether, and the like. Examples of the ketone include acetone, Examples of the ester include, for example, ethyl lactate, butyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, diethyl oxalate, and malon Diethyl acetate, isoamyl propionate, isoamyl isobutyrate, a compound represented by the above formula (b-1A), a 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;
Examples of the halogenated hydrocarbon include dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene, and the like. Examples of the hydrocarbon include 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 phenol solvent (organic solvent A), or one or more selected from the organic solvent A, and alcohol, ketone, ester, It is preferable to use a mixture with one or more selected from the group consisting of ethers, halogenated hydrocarbons and hydrocarbons (organic solvent B). In the latter case, the proportion of the organic solvent B used is preferably 50% by weight or less, more preferably 40% by weight or less, and still more preferably 30% by weight with respect to the total amount of the organic solvent A and the organic solvent B. % Or less. The amount of organic solvent used (a) is such that the total amount (b) of tetracarboxylic dianhydride and diamine is 0.1 to 50% by weight based on the total amount (a + b) of the reaction solution. It is preferable.

  As described above, a reaction solution obtained by dissolving polyamic acid is obtained. This reaction solution may be used as it is for the preparation of the liquid crystal aligning agent, may be used for the preparation of the liquid crystal aligning agent after isolating the polyamic acid contained in the reaction solution, or the isolated polyamic acid was purified. You may use for preparation of a liquid crystal aligning agent. When polyamic acid is dehydrated and cyclized into a polyimide, the above reaction solution may be directly subjected to dehydration and cyclization reaction, or may be subjected to dehydration and cyclization 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 dehydrating and ring-closing and imidizing the polyamic acid synthesized as described above.

  The polyimide may be a completely imidized product obtained by dehydrating and cyclizing all of the amic acid structure possessed by the polyamic acid that is the precursor, and only a part of the amic acid structure is dehydrated and cyclized, It may be a partially imidized product in which an imide ring structure coexists. The polyimide in the present invention preferably has an imidation ratio of 30% or more, more preferably 40 to 99%, and still more preferably 50 to 99%. This imidation ratio represents the ratio of the number of imide ring structures to the total of the number of polyimide amic acid structures and the number of imide ring structures in percentage. Here, a part of the imide ring may be an isoimide ring.

The polyamic acid is preferably dehydrated and closed by heating the polyamic acid, or by dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydrating ring-closing catalyst to the solution, and heating the solution as necessary. . Of these, the latter method is preferred.
In the method of adding a dehydrating agent and a dehydrating ring-closing catalyst to the polyamic acid solution, for example, an acid anhydride such as acetic anhydride, propionic anhydride, or trifluoroacetic anhydride can be used as the dehydrating agent. It is preferable that the usage-amount of a dehydrating agent shall be 0.01-20 mol with respect to 1 mol of the amic acid structure of a polyamic acid. As the dehydration ring closure catalyst, for example, tertiary amines such as pyridine, collidine, lutidine, triethylamine and the like can be used. It is preferable that the usage-amount of a dehydration ring-closing catalyst shall be 0.01-10 mol with respect to 1 mol of dehydrating agents to be used. Examples of the organic solvent used in the dehydration ring-closing reaction include the organic solvents exemplified as those used for the synthesis of polyamic acid. The reaction temperature of the dehydration ring closure reaction is preferably 0 to 180 ° C, more preferably 10 to 150 ° C. The reaction time is preferably 1.0 to 120 hours, more preferably 2.0 to 30 hours.

  In this way, a reaction solution containing polyimide is obtained. This reaction solution may be used for the preparation of the liquid crystal aligning agent as it is, may be used for the preparation of the liquid crystal aligning agent after removing the dehydrating agent and the dehydrating ring-closing catalyst from the reaction solution, and the liquid crystal after isolating the polyimide. You may use for preparation of an aligning agent, or you may use for preparation of a liquid crystal aligning agent, after purifying the isolated polyimide. These purification operations can be performed according to known methods.

<Polyamic acid ester>
The polyamic acid ester contained in the liquid crystal aligning agent of the present invention is synthesized, for example, by reacting 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. [II] a method of reacting a tetracarboxylic acid diester with a diamine, and [III] a method of reacting a tetracarboxylic acid diester dihalide with a diamine.

  Here, examples of the hydroxyl group-containing compound used in the method [I] include alcohols such as methanol, ethanol and propanol; 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, and as an epoxy group-containing compound, Examples thereof include propylene oxide. 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 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 diamines exemplified in the synthesis of the polyamic acid can be used. The polyamic acid ester may have only an amic acid ester structure, or may be a partially esterified product in which an amic acid structure and an amic acid ester structure coexist.

<Solution viscosity and weight average molecular weight>
The polyamic acid, polyimide and polyamic acid ester obtained as described above preferably have a solution viscosity of 10 to 800 mPa · s, when this is made into a solution having a concentration of 10% by weight. More preferably, it has a solution viscosity of s. In addition, the solution viscosity (mPa · s) of the above polymer is based on a polymer solution having a concentration of 10% by weight prepared using a good solvent for the polymer (eg, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.). The value measured at 25 ° C. using an E-type rotational viscometer.
The reduced viscosity is not particularly limited as long as a uniform coating film can be formed, but is preferably 0.05 to 3.0 dl / g, and preferably 0.1 to 2.5 dl / g. Is more preferable, and it is still more preferable that it is 0.3-1.5 dl / g.
For 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. More preferably, it is 1,000 to 50,000.

≪Solvent≫
The liquid crystal aligning agent which concerns on this invention is at least 1 type of organic solvent chosen from the group which consists of a compound represented by the compound represented by the said Formula (b-1A), and a following formula (b-1B) as a solvent component ( 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 is made narrower. In this case, good display quality can be maintained.

[Specific solvent (B)]
(Compound represented by Formula (b-1A))
Regarding the compound represented by the above 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, C1-C5 alkyl groups such as butyl group, isobutyl group, tertiary butyl group, pentyl group and neopentyl group; monovalent unsaturated chain hydrocarbons having 2 or 3 carbon atoms such as vinyl group and allyl group Group; and the like. Among ^these, it is preferable that R 8 ^{to R 10} is a methyl group or an ethyl ^group, more preferably R 8 ^{to R 10} are all methyl groups. R ^{8 to} R ¹⁰ may be the same as or different from each other.
Preferable specific examples of the compound represented by the formula (b-1A) include alkyl 2-hydroxyisobutyrate, for example, methyl 2-hydroxyisobutyrate. As the compound represented by the above formula (b-1A), the above-mentioned compounds can be used alone or in combination of two or more.

(Compound represented by Formula (b-1B))
About the compound represented by the said Formula (b-1B), as a specific example of a C1-C5 monovalent hydrocarbon group in R < ⁸ >, R < ⁹ > and R < ¹¹ >, R of the said Formula (b-1A) description ⁸ to R ¹⁰ can be applied. Among these, R ⁸ and R ⁹ are each preferably a hydrogen atom, a methyl group or an ethyl group. R ¹¹ is preferably an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tertiary 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 as or different from each other.
X is an OH group or an SH group, and is preferably an OH group. n is 0 or 1, and is preferably 0.
Preferable specific examples of the compound represented by the formula (b-1B) include alkyl glycolate, and examples thereof include butyl glycolate. As the compound represented by the above formula (b-1B), the above-mentioned compounds can be used alone or in combination of two or more.

(Other solvents)
It is preferable that the liquid crystal aligning agent of this invention contains other solvents other than the said specific solvent (B) as a solvent component. Examples of the other solvent include 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). 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 Examples include formamide, N, N-dimethylacetamide, 1,3-dimethyl-2-imidazolidinone, N-ethyl-2-pyrrolidone, dimethyl sulfoxide, tetramethylurea, hexamethylphosphortriamide, m-cresol and the like. In addition, the 1st solvent can use said thing individually by 1 type or in mixture of 2 or more types.

  Examples of the poor solvent for the polymer (A) and an organic solvent other than the specific solvent (B) (hereinafter also referred to as “other poor solvents”) include, for example, ethylene glycol monomethyl ether, butyl lactate, acetic acid. Butyl, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol-n-butyl ether (butyl cellosolve ), Ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate Diethylene glycol monoethyl ether acetate, dipropylene glycol monomethyl ether (DPM), diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, ethylene carbonate, propylene carbonate, diacetone alcohol, diethylene glycol diethyl ether, diisopentyl ether, propylene glycol di An acetate etc. can be mentioned. The said organic solvent can use the said thing individually by 1 type or in mixture of 2 or more types. Hereinafter, the group consisting of the other poor solvent and the specific solvent (B) is also referred to as a “second solvent”.

Among the other solvents, the content ratio of the first solvent is preferably 5% by weight or more with respect to the total amount of the solvent contained in the liquid crystal aligning agent from the viewpoint of suppressing the precipitation of the polymer (A). Yes, more preferably 10% by weight or more, still more preferably 20% by weight or more. Further, the upper limit value of the content ratio of the first solvent is preferably 95% 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 still more 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, more preferably 70% by weight with respect to 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 relative to the amount of the first solvent used is 0.03 times (weight) or more from the viewpoint of improving the coating property to 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 does not substantially contain butyl cellosolve as a solvent. Conventionally, butyl cellosolve is generally used in the preparation of a liquid crystal aligning agent as a solvent component for improving the coating property of the liquid crystal aligning agent on a substrate. However, when butyl cellosolve is used, precipitates tend to be generated in the liquid crystal aligning agent when stored for a long period of time, for example, in an extremely low temperature environment of −15 ° C. or lower. In addition, products stored at a low temperature are sometimes transported in a state of being stored in dry ice, and are often exposed to a lower temperature (for example, -20 ° C. or lower). In such a case, precipitates are more likely to be generated in the liquid crystal aligning agent. On the other hand, the specific solvent (B) hardly deposits in the liquid crystal aligning agent even when the liquid crystal aligning agent is stored at a low temperature for a long period of time, and imparts excellent storage stability to the liquid crystal aligning agent. It is possible. The specific solvent (B) is useful as an alternative to butyl cellosolve because it imparts excellent coating properties to the liquid crystal aligning agent.
In this specification, “substantially free of butyl cellosolve” means that the content of butyl cellosolve is preferably 5% by weight or less, more preferably 3%, based on the total amount of the solvent contained in the liquid crystal aligning agent. It means less than wt%, more preferably less than 0.5 wt%.

《Other ingredients》
The liquid crystal aligning agent according to the present invention contains the polymer (A) and the solvent as described above, 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, Examples include the amine compound (C).

[Other polymers]
The above 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, the blending ratio is preferably 50% by weight or less, more preferably 0.1 to 40% by weight, based on the total amount of the polymer components in the liquid crystal aligning agent. Preferably, 0.1 to 30% by weight is more preferable.

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

[Functional silane compounds]
The functional silane compound can be used for the purpose of improving the printability of the liquid crystal aligning agent. Examples of such functional silane compounds include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl). ) -3-Aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3- Aminopropyltrimethoxysilane, N-triethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-trimethoxysilyl -3,6- Methyl azananoate, N-benzyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, glycidoxymethyltrimethoxysilane, 2-glycidoxyethyltrimethoxysilane, 3-glycid And xylpropyltrimethoxysilane.
When these functional silane compounds are added to the liquid crystal aligning agent, the blending ratio is preferably 2 parts by weight or less, more preferably 0.02 to 0.2 parts by weight, based on 100 parts by weight of the total polymer.

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

  The nitrogen-containing aromatic heterocycle in the amine compound (C) may be an aromatic ring containing one or more nitrogen atoms in the ring skeleton. Therefore, the ring skeleton may contain only nitrogen atoms as heteroatoms, or may contain nitrogen atoms and heteroatoms other than nitrogen atoms (oxygen atoms, sulfur atoms, etc.). Specific examples of the nitrogen-containing aromatic heterocycle include, for example, pyrrole ring, imidazole ring, pyrazole ring, triazole ring, pyridine ring, pyrimidine ring, pyridazine ring, pyrazine ring, indole ring, benzimidazole ring, purine ring, 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, An oxadiazole ring etc. are mentioned. Further, the nitrogen-containing aromatic heterocycle may be one in which a substituent is introduced into the carbon atom constituting the ring exemplified above. Examples of the substituent include a halogen atom, an alkyl group, and an alkoxy group.

  The chain hydrocarbon group in the amine compound (C) preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and still more preferably 1 to 10 carbon atoms. The chain hydrocarbon group may be linear or branched and may be saturated or unsaturated. Moreover, as an alicyclic hydrocarbon group in the said amine compound (C), it is preferable that it is C3-C20, it is more preferable that it is C3-C15, and it is C3-C10. Further preferred.

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

In the formula (c-1), examples of the divalent organic group in A ¹ include a divalent chain hydrocarbon group, a divalent alicyclic hydrocarbon group, —O—R ²¹ —, —CO. -R ²¹ - (. ^{However, R 21} is a divalent a chain hydrocarbon group or an alicyclic hydrocarbon group). In addition, as the divalent organic group, between a carbon-carbon bond in a divalent chain hydrocarbon group or a divalent alicyclic hydrocarbon group, —O—, —NH—, —CO—O— _{, -CO-NH -, - CO} -, - S -, - S (O) 2 -, - Si (CH 3) 2 -, - O-Si (CH 3) 2 -, - O-Si (CH 3 ) ₂ -O-, a divalent group having an aromatic hydrocarbon group such as a phenylene group, a heterocyclic group such as a pyridinylene group; 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; It may be. 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).

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

Specific examples of the amine compound (C) include compounds represented by the following formulas (c-1-1) to (c-1-32). In addition, as an amine compound (C), 1 type of these can be used individually or in combination of 2 or more types.

In the case where the amine compound (C) is added to the liquid crystal aligning agent, the blending ratio thereof is 1 weight with respect to a total of 100 parts by weight of the polymer from the viewpoint of suitably obtaining the effect of adding the amine compound (C). Part or more, preferably 2 parts by weight or more. 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 with respect to 100 parts by weight of the total of the polymer.
As other additives to be contained in the liquid crystal aligning agent, in addition to the above, a compound having at least one oxetanyl group in the molecule, an antioxidant, or the like can be used.

When the amine compound (C) is contained as an additive in the liquid crystal aligning agent according to the present invention, the polymer (A) is preferable in that the electrical characteristics of the liquid crystal display element can be suitably improved. It preferably has a carboxyl group. Moreover, it is preferable that the number of the carboxyl groups which the said polymer (A) has is 0.1-3 in an average value per repeating unit of a polymer (A), and shall be 0.3-2 Is more preferably 0.5 to 1.8.
The method for adjusting the number of carboxyl groups of the polymer (A) is not particularly limited. For example, (i) a method for adjusting the imidation ratio of polyimide, (ii) for the synthesis of the polymer (A) The method performed by adjusting the carboxyl group content of the diamine to be used, and the like. Moreover, you may carry out by using together said (i) and (ii). From the viewpoint of increasing the degree of freedom of the imidization rate of the polymer (A), it is preferable to use the method (ii).

  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). , 0.01-2 mol, more preferably 0.05-1 mol, still more preferably 0.08-0.8 mol.

  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 substrate surface as described later, and preferably heated to form a coating film that is a liquid crystal alignment film or a coating film that becomes a liquid crystal alignment film. At this time, when 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, it is difficult to obtain a good liquid crystal alignment film due to excessive film thickness, and the viscosity of the liquid crystal aligning agent increases, resulting in poor coating characteristics. It becomes.

  The particularly preferable range of the solid content concentration varies depending on the method used when the liquid crystal aligning agent is applied to the substrate. For example, when the spin coating method is used, the solid content concentration is particularly preferably in the range of 1.5 to 4.5% by weight. In the case of the offset printing method, it is particularly preferable that the solid content concentration is in the range of 3 to 9% by weight, and thereby the solution viscosity is in the range of 12 to 50 mPa · s. In the case of the ink jet method, it is particularly preferable that the solid content concentration is in the range of 1 to 8% by weight, and thereby the solution viscosity is in the range of 3 to 20 mPa · s. The temperature at the time of preparing the liquid crystal aligning agent of this invention becomes like this. Preferably it is 10-50 degreeC, More preferably, it is 20-30 degreeC.

<Liquid crystal alignment film and liquid crystal display element>
The liquid crystal alignment film according to the present invention is formed by the liquid crystal aligning agent prepared as described above. Moreover, the liquid crystal display element which concerns on this invention comprises the liquid crystal aligning film formed using the said liquid crystal aligning agent. A driving mode to which the liquid crystal display element is applied is not particularly limited, and can be applied to various driving modes such as a TN type, STN type, IPS type, FFS type, VA type, and MVA type. Below, while manufacturing the liquid crystal display element which concerns on this invention, the manufacturing method of a liquid crystal aligning film is demonstrated in the description.

  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 to be used varies depending on the desired drive mode. Step (2) and step (3) are common to each drive mode.

[Step (1): Formation of coating film]
First, the liquid crystal aligning agent of this invention is apply | coated on a board | substrate, Then, a coating film is formed on a board | substrate by heating an application surface.
(1-1) When manufacturing a TN type, STN type, or VA type liquid crystal display element, a pair of two substrates provided with a patterned transparent conductive film is used as a pair on each transparent conductive film formation surface. 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 ink jet printing method. Here, as the substrate, for example, glass such as float glass or soda glass; a transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, poly (cycloaliphatic olefin) can be used. As a transparent conductive film provided on one surface of the substrate, an NESA film (registered trademark of PPG, USA) made of tin oxide (SnO ₂ ), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ), etc. Can be used. In order to obtain a patterned transparent conductive film, for example, a method of forming a pattern by photo-etching after forming a transparent conductive film without a pattern, a method of using a mask having a desired pattern when forming a 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, a functional silane compound or functional titanium is formed on the surface of the substrate surface on which the coating film is to be formed. You may give the pretreatment which apply | coats a compound etc. previously.

  After the application of the liquid crystal aligning agent, preheating (pre-baking) is preferably performed for the purpose of preventing dripping of the applied aligning agent. The pre-baking temperature is preferably 30 to 200 ° C, more preferably 40 to 150 ° C, and particularly preferably 40 to 100 ° C. The pre-bake time is preferably 0.25 to 10 minutes, more preferably 0.5 to 5 minutes. Then, a baking (post-baking) process is implemented for the purpose of removing a solvent completely and heat imidating the amic acid structure which exists in a polymer as needed. The firing (post-bake) temperature is preferably 80 to 300 ° C, more preferably 120 to 250 ° C. The post-bake time is preferably 5 to 200 minutes, more preferably 10 to 100 minutes. The 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 forming surface of a substrate provided with an electrode made of a transparent conductive film or a metal film patterned in a comb shape, and an electrode are provided. The liquid crystal aligning agent which concerns on this invention is each apply | coated to one surface of the counter substrate which is not, and then a coating film is formed by heating each application surface. Regarding the material used for the substrate and the transparent conductive film, the coating method, the heating conditions after coating, the patterning method for the transparent conductive film or the metal film, the pretreatment of the substrate, and the preferred film thickness of the coating film to be formed The same as (1-1). As the metal film, for example, a film made of a metal such as chromium can be used.

  In both cases (1-1) and (1-2), after applying a liquid crystal aligning agent on the substrate, a coating film to be an alignment film is formed by removing the organic solvent. At this time, when the polymer contained in the liquid crystal aligning agent is a polyamic acid or an imidized polymer having an imide ring structure and an amic acid structure, by further heating after forming the coating film It is good also as a coating film which advanced dehydration ring-closing reaction and was made more imidized.

[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 step (1) is subjected to a treatment for imparting liquid crystal alignment ability. Thereby, the orientation ability of a liquid crystal molecule is provided to a coating film, and it becomes a liquid crystal aligning film. Examples of the treatment include 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 photo-alignment treatment in which the coating film is irradiated with polarized or non-polarized radiation. Is mentioned. On the other hand, when manufacturing a VA type liquid crystal display element, the coating film formed in the above step (1) can be used as it is as a liquid crystal alignment film, but even if the coating film is subjected to alignment ability imparting treatment. Good.

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

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

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

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

  And a liquid crystal display element can be obtained by sticking a polarizing plate on the outer surface of a liquid crystal cell. As a polarizing plate to be bonded to the outer surface of the liquid crystal cell, a polarizing film or an H film itself in which a polarizing film called an “H film” in which iodine is absorbed while stretching and aligning polyvinyl alcohol is sandwiched between cellulose acetate protective films The polarizing plate which consists of can be mentioned. When the rubbing treatment is performed on the coating film, the two substrates are arranged to face each other so that the rubbing directions in each coating film 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, such as watches, portable games, word processors, notebook computers, car navigation systems, camcorders, PDAs, digital cameras, mobile phones, smartphones. In addition, it can be used for display devices such as various monitors and liquid crystal televisions.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

In the following Examples and Comparative Examples, the imidization ratio of polyimide in the polymer solution and the weight average molecular weight Mw of the polymer were measured by the following methods.
[Imidation rate of polyimide]
The polyimide solution was poured into pure water, and the resulting 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 imidation ratio [%] was determined by the following formula (x).
Imidation rate [%] = (1-A ¹ / A ² × α) × 100 (x)
(In Formula (x), A ¹ is the peak area derived from proton of NH group appearing in the vicinity of the chemical shift 10 ppm, A ² is the peak area derived from other protons, alpha precursor (polyamic acid polymer The number ratio of other protons to one proton of NH group in)
[Weight average molecular weight of polymer]
The weight average molecular weight Mw is a polystyrene equivalent value measured by gel permeation chromatography under the following conditions.
Column: Tosoh Co., Ltd., TSKgelGRCXLII
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 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 tetracarboxylic dianhydride, and the solid content concentration was further increased. NMP was added so that it might become 12 weight%, and it stirred at room temperature under nitrogen atmosphere for 4 hours, and obtained the solution of polyamic acid (PA-1).
To this polyamic acid solution, NMP and methyl 2-hydroxyisobutyrate (HBM) as a specific solvent (B) are added (NMP: HBM = 60: 40 (weight ratio)), and the polyamic acid concentration is 6.0% by weight. The liquid crystal aligning agent (S1A) was prepared so that it might become.

[Example 2A]
19.2 g (0.098 mol) of CBDA as tetracarboxylic dianhydride and 24.2 g (0.1 mol) of 1,5-bis (4-aminophenoxy) pentane as diamine are dissolved in 343.5 g of NMP, and 10 at room temperature. 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) are added (NMP: HBM = 50: 50 (weight ratio)), and the polyamic acid concentration A liquid crystal aligning agent (S2A) was prepared so as to be 6.0 wt%.

[Example 3A]
2,3,5-tricarboxycyclopentylacetic acid dianhydride 22.42 g (0.1 mol) as tetracarboxylic dianhydride and 18.73 g of 4,4′-diaminodiphenylamine (4,4′DADPA) as diamine ( 0.094 mol) was mixed in 345.1 g of NMP and reacted at room temperature for 5 hours. The polymerization reaction proceeded easily and uniformly 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) are added (NMP: HBM = 80: 20 (weight ratio)), and the polyamic acid concentration A liquid crystal aligning agent (S3A) was prepared so as to be 6.0 wt%.

[Example 4A]
As a diamine, 6.5 g (0.06 mol) of p-PDA and 4- (4-trans-n-heptylcyclohexyl) phenoxy) -1,3-diaminobenzene (PCH7DAB, represented by the above formula (d-4-3)) Compound) 15.22 g (0.04 mol) is dissolved in 165 g of NMP, CBDA 19.41 g (0.099 mol) is added thereto as tetracarboxylic dianhydride, and reacted at room temperature for 24 hours. -4) was obtained. The obtained polyamic acid (PA-4) had a weight average molecular weight (Mw) of 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.

[Example 5A]
1.46 g (13.5 mmol) of p-PDA as diamine and 0.78 g (1.50 mmol) of cholestanyl 3,5-diaminobenzoate (DA-3) were mixed in 20.0 g of NMP, and tetracarboxylic dianhydride. As a product, 2.85 g (14.5 mmol) of CBDA was added, 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). Subsequently, NMP and methyl 2-hydroxyisobutyrate (HBM) as the specific solvent (B) were added to 40.0 g of the obtained polyamic acid solution (NMP: HBM = 75: 25 (weight ratio)), and the polyamic acid concentration A liquid crystal aligning agent (S5A) was prepared so as to be 4.0 wt%.

[Example 6A]
CBDA (2.58 g, 13.1 mmol) as tetracarboxylic dianhydride and PCH7DAB (5.0 g, 13.1 mmol) as diamine were dissolved in 43 g of NMP and stirred at 20 ° C. for 4 hours to react with polyamic acid (PA-6). ) Was obtained. Next, to the obtained NMP solution of polyamic acid (PA-6), NMP and methyl 2-hydroxyisobutyrate (HBM) as a specific solvent (B) are added (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]
NMP91 is pyromellitic dianhydride (PMDA) 8.724 g (0.04 mol) as tetracarboxylic dianhydride, p-PDA 2.877 g (0.0266 mol) and PCH7DAB 4.567 g (0.012 mol) as diamine. In 6 g at room temperature for 3 hours to prepare a solution containing polyamic acid (PA-7). 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 wt. The liquid crystal aligning agent (S7A) was prepared so that it might become%.

[Example 8A]
2.64 g (0.072 mol) of 2,4-diamino-N, N-diallylaniline as diamine, 2.96 g (0.016 mol) of n-dodecylamine as monoamine, and 15.69 g of CBDA as tetracarboxylic dianhydride (0.08 mol) was reacted in 300 g of NMP at room temperature for 4 hours to prepare a solution containing a polyamic acid intermediate (PA-8). To the NMP solution of this polyamic acid intermediate, NMP and methyl 2-hydroxyisobutyrate (HBM) as a specific solvent (B) are added (NMP: HBM = 60: 40 (weight ratio)), and the solid content concentration is 6.0. A weight percent liquid crystal aligning agent (S8A) was prepared.

[Example 9A]
Bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic acid 2: 4,6: 8-dianhydride (BODA) 4.50 g (0.018 mol) as tetracarboxylic dianhydride Then, 0.68 g (0.0018 mol) of PCH7DAB and 1.75 g (0.0162 mol) of p-PDA were reacted as diamines at room temperature in 39.3 g of NMP, and further reacted at 40 ° C. for 43 hours. NMP is added to 42 g of this polyamic acid solution to prepare a 1% by weight solution. To this, 4.18 g of acetic anhydride and 6.48 g of pyridine are added as an imidization catalyst, and the reaction is performed at room temperature for 30 minutes and at 120 ° C. for 2 hours. I let you. This solution was poured into a large amount of methanol, and the resulting white precipitate was separated by filtration and dried to obtain a white polyimide powder. It was 72% when the imidation ratio of the obtained polyimide powder (polyimide (PI-1)) was measured. To this powder, NMP and methyl 2-hydroxyisobutyrate (HBM) as a specific solvent (B) are 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]
For the solvent composition of the liquid crystal aligning agent, a polymer was synthesized and the liquid crystal aligning agent was used in the same manner as in Examples 1A to 9A, except that butyl cellosolve (BC) was used as the second solvent instead of the specific solvent (B). It prepared and obtained liquid crystal aligning agent (R1A)-(R9A), respectively. Note that Comparative Example XA (X is an integer of 1 to 9) is an example corresponding to Example XA. That is, in Comparative Example XA, the same polymer as in Example XA was synthesized, and a liquid crystal aligning agent was prepared in the same manner as in Example XA, except that butyl cellosolve was used instead of the specific solvent (B).

[Example 10A]
Bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic acid 2: 4,6: 8-dianhydride (BODA) 4.50 g (0.018 mol) as tetracarboxylic dianhydride As a diamine, 2.34 g (0.0054 mol) of the compound represented by the above formula (d-4-2) as a diamine and 1.92 g (0.0126 mol) of 3,5-diaminobenzoic acid (35 DAB) were added to NMP26. After reacting in 3 g at room temperature, it was further reacted at 40 ° C. for 43 hours. NMP is added to 30 g of this polyamic acid solution to prepare a 6% by weight solution. To this, 2.4 g of acetic anhydride and 1.8 g of pyridine are added as an imidation catalyst, and the reaction is performed at room temperature for 30 minutes and at 110 ° C. for 4 hours. I let you. This solution was poured into a large amount of methanol, and the resulting 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 obtained. 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 liquid crystal was stirred at 50 ° C. for 15 hours. An aligning agent (S10A) was obtained. In addition, the liquid crystal aligning agent was prepared so that a solvent composition might become NMP: D1: HBM = 30: 20: 50 (weight ratio).

[Example 11A]
The 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). Operation was performed to obtain a polyamic acid solution. Moreover, operation similar to Example 10A was performed using the obtained polyamic acid solution, and polyimide powder was obtained. 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 obtained. 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 liquid crystal was stirred at 50 ° C. for 15 hours. An aligning agent (S11A) was obtained. In addition, the liquid crystal aligning agent was prepared so that a solvent composition might become 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 resulting white precipitate was filtered 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 liquid crystal aligning agent (S12A) having a solid content concentration of 6.0% by weight was obtained.
[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 resulting white precipitate was filtered 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 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 was obtained as 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 resulting white precipitate was filtered 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: D1: HBM = 40: 40: 20 (weight ratio)) and a liquid crystal aligning agent (S14A) having 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 resulting white precipitate was filtered and dried to obtain a polyamic acid powder. This powder and N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane (E1) as an additive, NMP and 3-butoxy-N, N-dimethylpropionamide as a first solvent (D2) and a specific solvent (B) dissolved in a mixed solvent of methyl 2-hydroxyisobutyrate (HBM) (NMP: D2: HBM = 40: 40: 20 (weight ratio)), and a polyamic acid concentration of 6.0 A weight percent liquid crystal aligning agent (S15A) 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 Example 5A. This solution was poured into a large amount of methanol, and the resulting white precipitate was filtered 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 resulting white precipitate was filtered 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 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 resulting white precipitate was filtered and dried to obtain a polyamic acid powder. This powder was dissolved in a mixed solvent of NMP and γ-butyllactone (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 polyamic acid concentration of 6.0% by weight was obtained as a liquid crystal aligning agent (S18A).
[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 resulting white precipitate was filtered 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: D2: HBM = 30: 30: 40 (weight ratio)) and a liquid crystal aligning agent (S19A) having a polyamic acid concentration of 6.0% by weight was obtained.
[Example 20A]
In the same manner as in Example 9A, a polyimide (PI-1) powder was obtained. 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 liquid crystal aligning agent (S20A) having a solid content concentration of 6.0% by weight was obtained.

<Evaluation of storage stability>
About each liquid crystal aligning agent obtained above, after filtering with a 1.0 micrometer filter, after storing at -30 degreeC for 1 month, it returns to room temperature (25 degreeC), and the presence or absence of the deposit in a liquid crystal aligning agent is checked. 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 as “◯”, and the case where the precipitate was observed was indicated as “x”.
<Evaluation of printability>
About each liquid crystal aligning agent prepared above, after filtering with a 1.0 micrometer filter, after storing for 6 months at -15 degreeC, it returned to room temperature (25 degreeC). Subsequently, the liquid crystal aligning agent was apply | coated to the transparent electrode surface of the glass substrate with a transparent electrode which consists of an ITO film | membrane using the liquid crystal aligning film printer (made by Nissha Printing Co., Ltd.). Thereafter, the solvent was removed by heating (pre-baking) for 1 minute on an 80 ° C. hot plate, and then heating (post-baking) for 10 minutes on a 200 ° C. hot plate to form a coating film having an average film thickness of 600 mm. . This coating film was observed with a microscope having a magnification of 20 times to examine the presence or absence of printing unevenness and pinholes. The evaluation was carried out as a printability good (◯) when almost no printing unevenness and pinholes were observed, and as a printability defect (×) when at least one of printing unevenness and pinholes was observed. The results are shown in Tables 1 and 2 below.

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

<Manufacture and evaluation of photo-alignment FFS type liquid crystal display element>
(1) Production of FFS type liquid crystal display element using photo-alignment method FFS type liquid crystal display element 10 shown in FIG. 1 was produced. First, a glass substrate 11a having an electrode pair on one side of which a bottom electrode 15 having no pattern, a silicon nitride film as an insulating layer 14, and a top electrode 13 patterned in a comb shape are formed in this order, and an electrode The counter glass substrate 11b not provided with a pair is formed into a pair, and the liquid crystal aligning agent (S1A) obtained as described above is applied to the surface having the transparent electrode of the glass substrate 11a and one surface of the counter glass substrate 11b by an inkjet coating method. A coating film was formed. Before applying the liquid crystal aligning agent (S1A) on the substrate, the viscosity is adjusted to 18 cP while keeping the solvent composition at “NMP: HBM = 60: 40 (weight ratio)”. The liquid crystal aligning agent was applied on the substrate.
Next, this coating film was pre-baked for 1 minute on a hot plate at 80 ° C., and then heated (post-baked) at 230 ° C. for 15 minutes in an oven in which the inside of the chamber was replaced with nitrogen, so that the average film thickness was 1,000 mm. A coating film was formed. A schematic plan view of the top electrode 13 used here is shown in FIG. 2A is a top view of the top electrode 13, and FIG. 2B is an enlarged view of a portion C1 surrounded by a broken line in FIG. 2A. In this example, a substrate having a top electrode having a line width d1 of electrodes of 4 μm and a distance d2 between the electrodes of 6 μm was used. Further, as the top electrode 13, four types of drive electrodes of electrode A, electrode B, electrode C, and electrode D were used. FIG. 3 shows the configuration of the drive electrodes of this liquid crystal display element. In this case, the bottom electrode 15 functions as a common electrode that acts on all of the four drive electrodes, and each of the four drive electrode regions serves as a pixel region.

Next, each surface of these coating films is irradiated with polarized ultraviolet rays 300 J / m ² containing a 313 nm emission line from the substrate normal direction using a Hg—Xe lamp and a Grand Taylor prism, respectively, and has a liquid crystal alignment film. Substrate was obtained. At this time, the irradiation direction of polarized ultraviolet rays is from the normal direction of the substrate, and the polarization plane direction is set so that the direction of the line segment in which the polarization plane of polarized ultraviolet rays is projected onto the substrate is the direction of the double-headed arrow in FIG. The light irradiation process was performed.

Next, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm is applied to the outer periphery of the surface of the substrate having the liquid crystal alignment film by screen printing, and the liquid crystal alignment film surfaces of the pair of substrates are then applied. It was made to oppose and it piled up and crimped | bonded so that the direction which the polarization plane of polarized ultraviolet rays projected on the board | substrate might become parallel, and the adhesive was thermoset at 150 degreeC over 1 hour. Next, a liquid crystal “MLC-6221” manufactured by Merck & Co. was filled into the gap between the liquid crystal injection port and the liquid crystal injection port was sealed with an epoxy resin adhesive. Then, in order to remove the flow alignment 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 laminating polarizing plates on both outer surfaces of the substrate. At this time, one of the polarizing plates is stuck so that the polarization direction thereof is parallel to the direction of projection of the polarization plane of the polarized ultraviolet light of the liquid crystal alignment film onto the substrate surface, and the other one has the polarization direction first. The polarizing plate was stuck so as to be orthogonal to the polarization direction of the polarizing plate.
The above method was repeated to produce a total of 5 FFS type liquid crystal display elements, one for each of the following evaluation of liquid crystal orientation, evaluation of heat resistance, resistance to bezel unevenness, afterimage characteristics and contrast characteristics. However, ultraviolet irradiation under voltage application was not performed in any case.

(2) Evaluation of liquid crystal orientation For the FFS type liquid crystal display device manufactured as described above, the presence or absence of abnormal domains in the change in brightness when a voltage of 5 V is turned ON / OFF (applied / released) is observed with a microscope at a magnification of 50 times. did. In the evaluation, when the abnormal domain was not observed, the liquid crystal alignment was “good”, and when the abnormal domain was observed, the liquid crystal alignment was “bad”. 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 device manufactured as described above, a voltage of 5 V was applied at 23 ° C. with an application time of 60 microseconds and a span of 167 milliseconds, and 167 milliseconds after the release of application. When the voltage holding ratio (VHR) was measured, the voltage holding ratio was 99.4%. In addition, as a measuring apparatus, Toyo Technica Co., Ltd. make and VHR-1 were used.
(4) Evaluation of heat resistance The voltage holding ratio was measured in the same manner as in the evaluation of the above (3) voltage holding ratio, and the value was defined as the initial VHR (VHR _BF ). Next, the liquid crystal display element after the initial VHR measurement was left in an oven at 100 ° C. for 500 hours. Thereafter, the liquid crystal display element was left at room temperature and allowed to cool to room temperature, and then the voltage holding ratio was measured in the same manner as described above, and the value was designated as VHR _AF . Further, the rate of change in voltage holding ratio (ΔVHR (%)) before and after application of thermal stress was determined by the following mathematical formula (EX-2).
ΔVHR (%) = ((VHR _BF −VHR _AF ) ÷ VHR _BF ) × 100 (EX−2)
In the evaluation of heat resistance, when the change rate ΔVHR is less than 4%, the heat resistance is “good”, when it is 4% or more and less than 5%, the heat resistance is “good”, and when it is 5% or more, the heat resistance is It was done as a sex “bad”. As a result, ΔVHR was 2.9%, and the heat resistance of this liquid crystal display element was “good”.

(5) Uneven resistance around the sealant (bezel unevenness resistance)
The FFS type liquid crystal display device manufactured above was stored for 30 days under conditions of 25 ° C. and 50% RH, and then driven with an AC voltage of 5 V to observe the lighting state. The evaluation is “excellent” if the luminance difference (more black or more white) is not visually recognized around the sealant, but “good” if the luminance difference disappears within 5 minutes after lighting. The case where the luminance difference disappeared within the super 20 minutes was judged “good”, and the case where the luminance difference was visually recognized even after 20 minutes passed was judged as “bad”. As a result, the luminance difference of the liquid crystal display element was not visually recognized, and was determined to be “excellent”.
(6) Evaluation of afterimage characteristics (DC afterimage evaluation)
The photo-alignment type liquid crystal display element produced above was placed in an environment of 25 ° C. and 1 atmosphere. The bottom electrode was set as a common electrode for all four drive electrodes, and the potential of the bottom electrode was set to 0 V potential (ground potential). The electrode B and the electrode D were short-circuited with the common electrode to be in a 0 V application state, and 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, an AC voltage of 1.5 V was applied to all of the electrodes A to D. Then, from the start of applying an AC voltage of 1.5 V to all drive electrodes, a drive stress application region (pixel region of electrode A and electrode C) and a drive stress non-application region (pixel region of electrode B and electrode D) The time until the difference in brightness with the eye could not be visually confirmed was measured, and this was defined as the afterimage erasing time. In addition, it shows that an afterimage is hard to produce, so that this time is short. The case where the afterimage erasing time was less than 30 seconds was evaluated as “good”, the case where it was 30 seconds or more and less than 120 seconds was evaluated as “good”, and the case where it was 120 seconds or more was evaluated as “bad”. The afterimage erasing time of the liquid crystal display element was 1 second, and the afterimage characteristics were evaluated as “good”.

<< Second Embodiment >>
[Example 1B]
A solution of polyamic acid (PA-1) was obtained by the same operation as in Example 1A. To this polyamic acid solution, NMP and butyl glycolate (BGA) as the specific solvent (B) are added (NMP: BGA = 60: 40 (weight ratio)), and the liquid crystal is adjusted so that the polyamic acid concentration becomes 6.0% by weight. An alignment agent (S1B) was prepared.
[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 the specific solvent (B) are added (NMP: BGA = 50: 50 (weight ratio)), and the polyamic acid concentration is 6.0. The liquid crystal aligning agent (S2B) was prepared so that it might become weight%.

[Example 3B]
A solution of polyamic acid (PA-3) was obtained in the same manner as in Example 3A. To this NMP solution of polyamic acid (PA-3), NMP and butyl glycolate (BGA) as the specific solvent (B) are added (NMP: BGA = 80: 20 (weight ratio)), and the polyamic acid concentration is 6.0. The liquid crystal aligning agent (S3B) was prepared so that it might become weight%.
[Example 4B]
A solution containing polyamic acid (PA-4) was obtained by the same operation as in Example 4A. The obtained polyamic acid (PA-4) had a weight average molecular weight (Mw) of 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.

[Example 5B]
A solution containing polyamic acid (PA-5) was obtained by the same operation as in 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 wt. The liquid crystal aligning agent (S5B) was prepared so that it might become%.
[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)), and the solid content The liquid crystal aligning agent (S6B) was prepared so that a density | concentration might be 3.0 weight%.

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

[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 the liquid crystal was adjusted to a solid content concentration of 4.5% by weight. An alignment agent (S9B) was prepared.
[Comparative Examples 1B to 9B]
For the solvent composition of the liquid crystal aligning agent, a polymer was synthesized and the liquid crystal aligning agent was used in the same manner as in Examples 1B to 9B except that butyl cellosolve (BC) was used as the second solvent instead of the specific solvent (B). It prepared and obtained liquid crystal aligning agent (R1B)-(R9B), respectively. Note that Comparative Example XB (X is an integer of 1 to 9) is an example corresponding to Example XB. That is, in Comparative Example XB, a liquid crystal aligning agent was prepared in the same manner as in Example XB except that the same polymer as in Example XB was synthesized and butyl cellosolve was used in place of the specific solvent (B).

[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), and the polyimide concentration The solution was 6.0% by weight. 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 liquid crystal was stirred at 50 ° C. for 15 hours. An aligning agent (S10B) was obtained. In addition, the liquid crystal aligning agent was prepared so that the solvent composition of a liquid crystal aligning agent might be set to NMP: D1: BGA = 30: 20: 50 (weight ratio).

[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), and the polyimide concentration The solution was 6.0% by weight. 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 liquid crystal was stirred at 50 ° C. for 15 hours. An aligning agent (S11B) was obtained. In addition, the liquid crystal aligning agent was prepared so that the solvent composition of a liquid crystal aligning agent might become NMP: D2: BGA = 30: 30: 40 (weight ratio).

[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 resulting white precipitate was filtered 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 ( Weight ratio)), and a liquid crystal aligning agent (S12B) having a solid concentration of 6.0% by weight was obtained.
[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 resulting white precipitate was filtered 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 ( Weight ratio)), and a liquid crystal aligning agent (S13B) having a polyamic acid concentration of 6.0% by weight was obtained.

[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 resulting white precipitate was filtered 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.
[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 resulting white precipitate was filtered and dried to obtain a polyamic acid powder. This powder and N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane (E1) as an additive, NMP and 3-butoxy-N, N-dimethylpropionamide as a first solvent (D2), and dissolved in a mixed solvent of butyl glycolate (BGA) as a specific solvent (B) (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.

[Example 16B]
A solution containing polyamic acid (PA-5) was prepared in the same manner as in Example 5A. This solution was poured into a large amount of methanol, and the resulting white precipitate was filtered 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.
[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 resulting white precipitate was filtered 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.

[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 resulting white precipitate was filtered and dried to obtain a polyamic acid powder. This powder was dissolved in a mixed solvent of NMP and γ-butyllactone (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.

[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 resulting white precipitate was filtered 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.
[Example 20B]
In the same manner as in Example 9A, a polyimide (PI-1) powder was obtained. 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 ( Weight ratio)), and a liquid crystal aligning agent (S20B) having a solid concentration of 6.0% by weight was obtained.

<Evaluation of storage stability>
About each liquid crystal aligning agent obtained above, the presence or absence of the deposit in a liquid crystal aligning agent was observed by the method similar to the said 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 as “◯”, and the case where the precipitate was observed was indicated as “x”.
<Evaluation of printability>
About each liquid crystal aligning agent prepared above, after filtering with a 1.0 micrometer filter, after storing for 6 months at -15 degreeC, it returned to room temperature (25 degreeC). Subsequently, the liquid crystal aligning agent was apply | coated to the transparent electrode surface of the glass substrate with a transparent electrode which consists of an ITO film | membrane using the liquid crystal aligning film printer (made by Nissha Printing Co., Ltd.). Thereafter, the solvent was removed by heating (pre-baking) for 1 minute on an 80 ° C. hot plate, and then heating (post-baking) for 10 minutes on a 200 ° C. hot plate to form a coating film having an average film thickness of 600 mm. . This coating film was observed with a microscope having a magnification of 20 times to examine the presence or absence of printing unevenness and pinholes. The evaluation was carried out as a printability good (◯) when almost no printing unevenness and pinholes were observed, and as a printability defect (×) 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.

<Manufacture 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 Example 1A is performed except that the liquid crystal aligning agent to be used is changed from (S1A) to (S1B), and is shown in FIG. An FFS type liquid crystal display element 10 was produced.
(2) Evaluation of liquid crystal orientation About the FFS type liquid crystal display element manufactured above, liquid crystal orientation was evaluated like Example 1A. As a result, this liquid crystal display element had “good” liquid crystal alignment.
(3) Evaluation of voltage holding ratio About the FFS type liquid crystal display element manufactured 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 About the FFS type liquid crystal display element manufactured above, heat resistance was evaluated similarly to Example 1A. As a result, ΔVHR was 2.9%, and the heat resistance of this liquid crystal display element was “good”.

(5) Uneven resistance around the sealant (bezel unevenness resistance)
About the FFS type liquid crystal display element manufactured above, the bezel unevenness resistance was evaluated in the same manner as in Example 1A. As a result, the luminance difference of the liquid crystal display element was not visually recognized, and was determined to be “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 device manufactured 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 characteristics were evaluated as “good”.

  As shown in Tables 1 to 4, all of the liquid crystal aligning agents of Examples using the specific solvent (B) have good storage stability when stored at a low temperature, and printability after storage at a low temperature. It was good. On the other hand, the liquid crystal aligning agent of the comparative example had poor storage stability and printability after low-temperature storage. From this, it was found that by using the specific solvent (B), the storage stability can be improved while ensuring applicability to the substrate. Further, in the liquid crystal display element using the liquid crystal aligning agent containing the specific solvent (B), the unevenness around the sealing agent is not visually recognized, and the bezel unevenness resistance is judged to be “excellent”, and the liquid crystal aligning agent that can achieve a narrow frame. The result which suggests is obtained. 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. Thereby, it was shown that the liquid crystal aligning film using the liquid crystal aligning agent containing the specific solvent (B) is suitable for providing the liquid crystal display element corresponding to a narrow frame.

  DESCRIPTION OF SYMBOLS 10 ... Liquid crystal display element, 11a, 11b ... Glass substrate, 12 ... Liquid crystal aligning film, 13 ... Top electrode, 14 ... Insulating layer, 15 ... Bottom electrode, 16 ... Liquid crystal layer

Claims (8)

A liquid crystal aligning agent comprising at least one polymer (A) selected from the group consisting of polyamic acid, polyimide and polyamic acid ester obtained by reacting tetracarboxylic dianhydride and diamine, and a solvent. And
The liquid crystal aligning agent in which the said solvent contains the compound represented by a following formula (b-1B) as a specific solvent (B).

(In Formula (b-1B), R ⁸ and R ⁹ are each independently a monovalent hydrocarbon group having 1 to 5 carbon atoms or a hydrogen atom , R ¹¹ is an n-butyl group, and X is OH group , n is 0.) 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-5). The liquid crystal aligning agent of Claim 1.

(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. 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. When n1 = 1, n2 = n3 = 1 In 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 from 1 to 12 in the case of m1 = 0, in m1 is m @ 2 = 2 in the case of an integer from 1 to 3. formula ^{(d-3), R} 3 has a carbon number is R ⁴ is a monovalent hydrocarbon group having 1 to 12 carbon atoms, 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 monovalent hydrocarbon group. In the formula (d-4), X ⁴ and X ⁵ are each independently a single bond, —O—, —COO— or —OCO—, and R ⁷ is a hydrogen atom or a methyl group. , An alkanediyl group having 1 to 3 carbon atoms, 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 an integer of 1 to 20, and k is 0 or 1. However, a and b are not simultaneously 0. In formula (d-5), A ¹ is a single bond, having 1 to 1 carbon atoms. 12 an alkanediyl group or a fluoroalkanediyl group having 1 to 6 carbon atoms, A ² represents —O—, —COO—, —OCO—, —NHCO—, —CONH— or —CO—, and A ³ Represents a monovalent organic group having a steroid skeleton.)   The liquid crystal aligning agent of Claim 1 whose content of the said specific solvent (B) is 1 to 70 weight% of the whole quantity of the said solvent. The polymer (A) is a compound represented by the following formula (t-1), 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride The liquid crystal aligning agent of any one of Claims 1-3 which is a polymer obtained using the tetracarboxylic dianhydride containing at least 1 type chosen from the group which consists of and pyromellitic dianhydride.

(In 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 is bonded to a chain hydrocarbon group or alicyclic hydrocarbon group (C The liquid crystal aligning agent as described in any one of Claims 1-4 which contains further. The liquid crystal aligning agent of Claim 5 whose said amine compound (C) is a compound represented by a 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 heterocyclic ring, provided that (The primary amino group in the formula is bonded to the chain hydrocarbon group or alicyclic hydrocarbon group which A ¹ has.) The liquid crystal aligning film formed using the liquid crystal aligning agent as described in any one of Claims 1-6 . A liquid crystal display device comprising the liquid crystal alignment film according to claim 7 .

Images