JP6127721B2 - 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, and more particularly to a liquid crystal aligning agent having good storage stability, and a liquid crystal aligning film and a liquid crystal display element manufactured using the liquid crystal aligning agent.

  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, usually with a good solvent such as polyamic acid, for example, butyl cellosolve 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.

  The present invention has been made in view of the above problems, and has as its main object 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.

  As a result of intensive studies to achieve the above-described problems of the prior art, the present inventors use a specific polymer as the polymer component of the liquid crystal aligning agent and use a specific solvent as at least a part of the solvent component. As a result, the present inventors have found that the above problems can be solved, and have completed the present invention. Specifically, the present invention provides the following liquid crystal aligning agent, liquid crystal 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. The polymer (A) is obtained using a diamine containing at least one selected from the group consisting of compounds represented by the following formulas (d-1) to (d-4). The liquid crystal aligning agent which is a polymer and the said solvent contains the specific solvent (B) which is at least 1 type chosen from the group which consists of a compound represented by each of following formula (b-1)-a formula (b-3). I will provide a.

（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の直鎖状又は分岐状の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の直鎖状若しくは分岐状の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。）

(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 C1-12 linear or branched monovalent hydrocarbon group, R ⁴ is a hydrogen atom, or a monovalent hydrocarbon of 1 to 12 carbon atoms linear or branched A containing group, ^{R 5} and ^{R 6} are independently a hydrogen atom or a methyl group in. The formula ^{(d-4), X} 4 and ^{X 5} each independently represent a single bond, -O-, -COO- or -OCO-, wherein R ⁷ is an alkanediyl group having 1 to 3 carbon atoms, a is 0 or 1, b is an integer of 0 to 2, and c is 1 to 20. (It is an integer and k is 0 or 1. However, a and b are not 0 at the same time.)

（式（ｂ−１）中、Ｒ^８及びＲ^１０は、それぞれ独立に炭素数１〜３の１価の炭化水素基であり、Ｒ^９は、炭素数２〜５のアルカンジイル基である。式（ｂ−２）中、Ｒ^１１は、炭素数３〜５の直鎖状若しくは分岐状のアルキル基の炭素−炭素結合間に「−Ｏ−」を１つ有する１価の基、炭素数３〜５の直鎖状若しくは分岐状のアルキル基の少なくとも１つの水素原子がヒドロキシル基で置換されてなる１価の基、又は炭素数３〜５の分岐状のアルキル基である。式（ｂ−３）中、Ｘ^６は、−Ｃ（ＯＨ）Ｒ^ａ−（但し、Ｒ^ａはメチル基又はエチル基である。）、−ＣＯ−又は−ＣＯＯ−＊（但し、＊はＲ^１２との結合手を示す。）であり、Ｒ^１２は、炭素数１〜４のアルキル基である。）

(In formula (b-1), R ⁸ and R ¹⁰ are each independently a monovalent hydrocarbon group having 1 to 3 carbon atoms, and R ⁹ is an alkanediyl group having 2 to 5 carbon atoms. In formula (b-2), R ¹¹ is a monovalent group having one “—O—” between carbon-carbon bonds of a linear or branched alkyl group having 3 to 5 carbon atoms, the number of carbon atoms It is a monovalent group formed by substituting at least one hydrogen atom of a linear or branched alkyl group of 3 to 5 with a hydroxyl group, or a branched alkyl group having 3 to 5 carbon atoms. -3), X ⁶ is —C (OH) R ^a — (wherein R ^a is a methyl group or an ethyl group), —CO— or —COO— * (where * is the same as R ¹² ) And R ¹² is an alkyl group having 1 to 4 carbon atoms.)

  When the polymer (A) obtained by using the specific diamine is used as at least part of the polymer component of the liquid crystal aligning agent and the specific solvent (B) is included as a solvent component, the Even when stored in a low temperature environment, precipitates are hardly generated in the alignment agent, and the 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 second aspect, the present invention contains at least one polymer selected from the group consisting of polyamic acid, polyimide, and polyamic acid ester, a solvent, and an additive. A specific solvent (B) that is at least one selected from the group consisting of compounds represented by formulas (b-3), and as the additive, one primary amino group and nitrogen in the molecule There is provided a liquid crystal aligning agent comprising an amine compound (C) having a contained aromatic heterocycle and having the primary amino group bonded to a chain hydrocarbon group or an alicyclic hydrocarbon group.

  In the liquid crystal aligning agent containing at least one polymer (A) selected from the group consisting of polyamic acid, polyimide and polyamic acid ester as at least a part of the polymer component, containing the amine compound (C) as an additive In such a case, when the liquid crystal aligning agent is stored for a long time in a low temperature environment, there may be a problem that the amine compound (C) is precipitated in the aligning agent. In this regard, according to the liquid crystal aligning agent in the second aspect of the present invention, the above-mentioned specific solvent (B) is included as a solvent component, so that 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.

（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。） In the second aspect, the amine compound (C) can be a compound represented by the following formula (c-1).

(In Formula (c-1), A ¹ is a divalent organic group having a chain hydrocarbon group or an alicyclic hydrocarbon group, and A ² is a nitrogen-containing aromatic heterocyclic ring.)

  In the second aspect, the polymer (A) is preferably a polymer having a carboxyl group. In this case, it is preferable that the average number of carboxyl groups of the polymer (A) is 0.1 to 3 per repeating unit of the polymer (A). Moreover, it is preferable to contain 0.01-2 mol of said amine compounds (C) with respect to 1 mol of carboxyl groups which the said polymer (A) has.

  In another aspect, the present invention provides a liquid crystal alignment film formed of the liquid crystal alignment agent, and a liquid crystal display device including the liquid crystal alignment film. Since the liquid crystal alignment film of the present invention is formed using the liquid crystal aligning agent on the first side or the liquid crystal aligning agent on the second side, the liquid crystal aligning agent is stored for a long time in a low temperature environment. In addition, applicability (printability) is good. Moreover, when manufacturing a liquid crystal display element using such a liquid crystal aligning film, a printing defect can be reduced in a manufacturing process, As a result, the yield of a product can be improved.

  The liquid crystal aligning agent of the present invention contains at least one polymer (A) selected from the group consisting of polyamic acid, polyimide and polyamic acid ester as a polymer component, and the polymer (A) is dispersed in a solvent. Alternatively, it is prepared as a liquid composition obtained by dissolution. Hereinafter, the liquid crystal aligning agent of this invention is demonstrated.

≪Polymer (A) ≫
<Polyamic acid>
The polyamic acid of the present invention can be obtained by reacting tetracarboxylic dianhydride with diamine.

（式（ｔ−１）中、Ｘ^７、Ｘ^８、Ｘ^９及びＸ^１０は、それぞれ独立に、単結合又はメチレン基であり、ｊは１〜３の整数である。）
で表される化合物などを；
芳香族テトラカルボン酸二無水物として、例えばピロメリット酸二無水物などを；それぞれ挙げることができるほか、特開２０１０−９７１８８号公報に記載のテトラカルボン酸二無水物を用いることができる。なお、テトラカルボン酸二無水物は、上記のものを１種単独で又は２種以上組み合わせて使用することができる。 [Tetracarboxylic dianhydride]
Examples of the tetracarboxylic dianhydride used for synthesizing the polyamic acid in the present invention include aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, aromatic tetracarboxylic dianhydride and the like. Can be mentioned. 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 in the present invention, among the above, the compound represented by the above formula (t-1), 1,2,3,4-cyclobutanetetracarboxylic dianhydride It is preferable to use at least one compound selected from the group consisting of a product and pyromellitic dianhydride (hereinafter also referred to as a specific tetracarboxylic dianhydride). When the specific tetracarboxylic dianhydride is used, the total amount of the specific tetracarboxylic dianhydride 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]
The diamine used for the synthesis of the polyamic acid in the present invention is represented by the compound represented by the above formula (d-1), the compound represented by the above formula (d-2), or the above formula (d-3). And at least one diamine selected from the group consisting of the compound represented by the above formula (d-4) (hereinafter also referred to as “specific diamine”).

(Compound represented by Formula (d-1))
In the above formula (d-1), examples of the alkanediyl group having 1 to 3 carbon atoms of R ¹ and R ² include a methylene group, an ethylene group, a propane-1,2-diyl group, and 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 a straight-chain or branched 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 linear or branched 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. , 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-4-11). .

  In synthesizing the polyamic acid of the present invention, 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 a liquid crystal aligning agent suitable for a vertical alignment type liquid crystal display element is produced by using the compound represented by the formula (d-4). be able to.

(Other diamines)
As the diamine used for synthesizing the polyamic acid in the present invention, 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, for example, metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine and the like as aliphatic diamines;
Examples of alicyclic diamines include 1,4-diaminocyclohexane, 4,4′-methylenebis (cyclohexylamine), 1,3-bis (aminomethyl) cyclohexane 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) -2,3-dihydro-1,3,3-trimethyl-1H-indene-6-amine, 3,5-diaminobenzoic acid, cholestanyloxy-3,5-diaminobenzene, cholestenyloxy-3, 5-diaminobenzene, cholestanyloxy-2,4-diaminobenzene, cholestenyloxy-2,4-diaminobenzene, cholestanyl 3,5-diaminobenzoate, cholestenyl 3,5-diaminobenzoate, 3,5-diamino Lanostanyl benzoate, 3,6-bis (4-aminobenzoyloxy) cholestane, 3,6-bis (4-aminophenoxy) cholestane, 4- (4′-trifluoromethoxybenzoyloxy) cyclohexyl-3,5- Diaminobenzoate, 4- (4′-trifluoromethylbenzoyloxy) cyclohexyl-3,5-di Aminobenzoate, 1,1-bis (4-((aminophenyl) methyl) phenyl) -4-butylcyclohexane, 1,1-bis (4-((aminophenyl) methyl) phenyl) -4-heptylcyclohexane, , 1-bis (4-((aminophenoxy) methyl) phenyl) -4-heptylcyclohexane, 1,1-bis (4-((aminophenyl) methyl) phenyl) -4- (4-heptylcyclohexyl) cyclohexane, 4-aminobenzylamine, 3-aminobenzylamine, 2,2-bis [4- (4-aminophenoxy) phenyl] propane and the like;
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 of the present invention contains a specific amine compound (C) described in detail below as an additive, a diamine having a carboxyl group as at least a part of the other diamine used for the synthesis of polyamic acid (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 the polyamic acid in this invention 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. Moreover, when using the compound represented by the said Formula (d-4), it is preferable to set the usage-amount to 5 mol% or more with respect to all the diamine from a viewpoint which provides favorable orientation. More preferably, it is 10 mol% or more. 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 the carboxyl group-containing diamine is used as the other diamine, the amount of the carboxyl group-containing diamine is preferably 5 mol% or more, more preferably 10 to 90 mol%, more preferably 10 to 90 mol%. 70 mol% is 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, the monomer used for the synthesis of the polyamic acid in the present invention is a tetracarboxylic acid dimer for the purpose of imparting an appropriate tilt alignment angle to the liquid crystal molecules. A monoamine represented by the following formula (m-1) may be used together with an anhydride and a 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. Among these, a chain hydrocarbon group, an alicyclic hydrocarbon group, or an aromatic hydrocarbon group is preferable.

  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 the 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 applicability (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, monoisocyanate compounds, and the like. 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 in the present invention is such that the acid anhydride group of the tetracarboxylic dianhydride is 0. A ratio of 2 to 2 equivalents is preferable, and a ratio of 0.3 to 1.2 equivalents is more preferable.
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 acid, isoamyl propionate, isoamyl isobutyrate 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 contained in the liquid crystal aligning agent of the present invention can be obtained by dehydrating and ring-closing 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. The amount of the dehydration ring closure catalyst used is preferably 0.01 to 10 moles per mole of the dehydrating agent 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 of 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 000-50,000.

≪Solvent≫
The liquid crystal aligning agent of the present invention includes, as a solvent component, a compound represented by the above formula (b-1), a compound represented by the above formula (b-2), and a compound represented by the above formula (b-3). It contains at least one organic solvent (specific solvent (B)) selected from the group consisting of: 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.

[Specific solvent (B)]
(Compound represented by Formula (b-1))
Regarding the compound represented by the above formula (b-1), examples of the monovalent hydrocarbon group having 1 to 3 carbon atoms in R ⁸ and R ¹⁰ include a methyl group, an ethyl group, an n-propyl group, and an isopropyl group. And an alkyl group having 1 to 3 carbon atoms; a monovalent unsaturated hydrocarbon group having 2 or 3 carbon atoms such as a vinyl group and an allyl group; Among these, R ⁸ and R ¹⁰ are preferably a methyl group or an ethyl group. R ⁸ and R ¹⁰ may be the same as or different from each other.
Examples of the alkanediyl group having 2 to 5 carbon atoms of R ⁹ include an ethylene group, a propane-1,2-diyl group, a propane-1,3-diyl group, a butane-1,3-diyl group, and a butane-1,4. -A diyl group, a pentane-1,5-diyl group, etc. can be mentioned.
Preferable specific examples of the compound represented by the formula (b-1) include alkylene glycol diacetates such as ethylene glycol diacetate and propylene glycol diacetate. Of these, propylene glycol diacetate can be preferably used. As the compound represented by the above formula (b-1), the above-mentioned compounds can be used alone or in combination of two or more.

(Compound represented by Formula (b-2))
The compound represented by the above formula (b-2) has a structure in which two R ¹¹ are each bonded to an oxygen atom. As such a compound, as a specific example of a compound in which R ¹¹ is a monovalent group having one “—O—” between carbon-carbon bonds of an alkyl group having 3 to 5 carbon atoms, for example, diethylene glycol dimethyl ether Specific examples of the compound in which R ¹¹ is a monovalent group in which a hydrogen atom of an alkyl group having 3 to 5 carbon atoms is substituted with a hydroxyl group include, for example, dipropylene glycol and the like; R ¹¹ Specific examples of the compound in which is a branched alkyl group include, for example, diisopropyl ether, diisopentyl ether, di-sec-butyl ether, di-sec-pentyl ether, and the like. Among these, the compound represented by the above formula (b-2) is preferably at least one of diethylene glycol diethyl ether and diisopentyl ether. In addition, as a compound represented by the said Formula (b-2), said thing can be used individually by 1 type or in combination of 2 or more types.

(Compound represented by Formula (b-3))
X ⁶ in the formula (b-3) is preferably ^a group “—C (OH) R ^a —”, and more preferably a group “—C (OH) (CH ₃ ) —”. The alkyl group having 1 to 4 carbon atoms of R ¹² may be linear or branched, and is preferably a methyl group or an ethyl group.
Preferable specific examples of the compound represented by the above formula (b-3) include, for example, diacetone alcohol, acetylacetone, ethyl acetoacetate and the like, and particularly diacetone alcohol can be preferably used. In addition, as a compound represented by the said formula (b-3), said thing can be used individually by 1 type or in combination of 2 or more types.

The specific solvent (B) is preferably at least one selected from the group consisting of a compound represented by the above formula (b-1) and a compound represented by the above formula (b-3). It is more preferable that it is a compound represented by (b-3).
The amount of the specific solvent (B) used is the total amount of the solvent contained in the liquid crystal aligning agent from the viewpoint of sufficiently obtaining the effect of improving the coatability (printability) to the substrate while suppressing the precipitation of the polymer. Is preferably 1 to 70% by weight, more preferably 3 to 65% by weight, and still more preferably 5 to 60% by weight. In addition, as a specific solvent (B), said thing can be used individually by 1 type or in combination of 2 or more types.

(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) contained in the liquid crystal aligning agent of the present invention (hereinafter also referred to as “first solvent”), and a poor solvent for the polymer (A). Thus, organic solvents other than the specific solvent (B) 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, 3-butoxy-N, N-dimethylpropionamide, γ-butyrolactone, γ-butyrolactam, N, N-dimethylformamide, 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 organic solvent other than the specific solvent (B) that are poor solvents for the polymer (A) include ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, and ethyl ethoxypropione. -Gene, 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, and propylene carbonate. The said organic solvent can use the said thing individually by 1 type or in mixture of 2 or more types. Hereinafter, a group consisting of an organic solvent other than the specific solvent (B) and the specific solvent (B), which is a poor solvent for the polymer (A), 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.

It is preferable that the liquid crystal aligning agent of this invention does not contain butyl cellosolve substantially 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 of the present invention contains the polymer (A) and a 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 a polyamic acid obtained by reacting a diamine not containing the specific diamine and a tetracarboxylic dianhydride, and a polyimide, polyester, polyamide obtained by dehydrating and ring-closing the polyamic acid, Examples thereof include 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 in the composition. 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 compounds are added to the liquid crystal aligning agent, the blending ratio is preferably 40 parts by weight or less, more preferably 0.1 to 30 parts by weight with respect to 100 parts by weight of the total of the polymers contained in the liquid crystal aligning agent. preferable.

[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。） 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.)

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.

Specifically, examples of the chain hydrocarbon group in A ¹ include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, a heptylene group, an octylene group, a nonylene group, a decylene group, an undecylene group, A dodecylene group, a tridecylene group, a tetradecylene group, a pentadecylene group, an octadecylene group, an icosylene group, a vinylene group, a propenylene group, a butenylene group, a pentenylene group, an ethynylene group, a propynylene group, etc .; For example, cyclopropylene group, cyclobutylene group, cyclopentylene group, cyclohexylene group, cyclohexenylene group, cycloheptylene group, cyclooctylene group, cyclononylene group, cyclodecylene group, cycloundecylene group, cyclododecylene group, cyclotridecylene A group, a cyclotetradecylene group, a cyclopentadecylene group, a cyclooctadecylene group, a cycloicosylene group, a bicyclohexylene group, a norbornylene group, an adamantylene group, and the like.
Of these, A ¹ is preferably a divalent organic group having a chain hydrocarbon group, and more preferably a divalent chain hydrocarbon group.
The divalent organic group for 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.
Examples of the nitrogen-containing aromatic heterocycle A ^2, it is possible to apply 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 said amine compound (C), 1 type of these can be used individually or in combination of 2 or more types.

When the amine compound (C) is added to the liquid crystal aligning agent, the blending ratio thereof is 1 with respect to a total of 100 parts by weight of the polymer from the viewpoint of suitably obtaining the effect of the addition of the amine compound (C). The amount is preferably at least part by weight, and more preferably at least 2 parts by weight. Further, from the viewpoint of not impairing the stability of the liquid crystal aligning agent, it is preferably 20 parts by weight or less, and more preferably 15 parts by weight or less 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 of the present invention, the polymer (A) is a carboxyl group in that the electrical characteristics of the liquid crystal display element can be suitably improved. It preferably has a 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 contained in the polymer (A) is not particularly limited. For example, (i) a method for adjusting the imidation ratio of polyimide, (ii) 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 of the present invention, the content of the amine compound (C) is 1 mol of the carboxyl group of the polymer (A). On the other hand, it is preferable to contain 0.01 to 2 mol, more preferably 0.05 to 1 mol, and still more preferably 0.08 to 0.8 mol.

  The solid content concentration in the liquid crystal aligning agent of the present invention (the ratio of the total weight of components other than the solvent of the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) is appropriately selected in consideration of viscosity, volatility, and the like. The range is preferably 1 to 10% by weight. That is, the liquid crystal aligning agent of 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. When the solid content concentration is less than 1% by weight, it is difficult to obtain a good liquid crystal alignment film because the film thickness is too small. 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 inkjet 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 of the present invention is formed by the liquid crystal aligning agent prepared as described above. Moreover, the liquid crystal display element of this invention comprises the liquid crystal aligning film formed using the liquid crystal aligning agent of this invention. The drive mode to which the liquid crystal display element of the present invention is applied is not particularly limited, and can be applied to various drive modes such as a TN type, STN type, IPS type, FFS type, VA type, and MVA type. Below, while explaining the manufacturing method of the liquid crystal display element of this invention, the manufacturing method of the liquid crystal aligning film of this invention is demonstrated in the description.

  The liquid crystal display element of the present invention can be produced, for example, by the following steps (1) to (3). In step (1), the substrate to be used varies depending on the desired drive mode. Steps (2) and (3) are common to each drive mode.

[Step (1): Formation of coating film]
First, the liquid crystal aligning agent of 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 of the present invention is preferably applied by an offset printing method, a spin coating method, a roll coater method or an ink jet printing method, respectively. 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. Thus, the film thickness of the formed film 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 of 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. About the material of the board | substrate used at this time and a transparent conductive film, the coating method, the heating conditions after application | coating, the patterning method of a transparent conductive film or a metal film, the pre-processing of a board | substrate, and the preferable film thickness of the coating film formed are the said ( It is the same as 1-1). As the metal film, for example, a film made of a metal such as chromium can be used.

  In 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 of the present invention is a polyamic acid or an imidized polymer having an imide ring structure and an amic acid structure, heating is further performed after the coating film is formed. By doing so, the dehydration ring-closing reaction may be advanced to form a more imidized coating film.

[Step (2): rubbing treatment]
When manufacturing a TN type, STN type, IPS type or FFS type liquid crystal display element, the coating film formed in the above step (1) is in a certain direction with a roll wound with a cloth made of fibers such as nylon, rayon, and cotton. Apply rubbing treatment. Thereby, the orientation ability of a liquid crystal molecule is provided to a coating film, and it becomes a liquid crystal aligning film. On the other hand, when manufacturing a VA type liquid crystal display element, the coating film formed in the step (1) can be used as it is as a liquid crystal alignment film, but the coating film may be subjected to a rubbing treatment.
In addition, for the liquid crystal alignment film after the rubbing treatment, 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, After forming a resist film in part and performing a rubbing process in a direction different from the previous rubbing process, a process for removing the resist film is performed so that the liquid crystal alignment film has different liquid crystal alignment capabilities for each region. Good. In this case, it is possible to improve the visibility characteristics of the obtained 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 to face each other through a gap (cell gap) so that the respective liquid crystal alignment films are opposed to each other, and the peripheral portions of the two substrates are bonded using a sealant, and the substrate surface and the sealant are bonded. A liquid crystal cell can be manufactured by injecting and filling liquid crystal into the cell gap partitioned by the step, and then sealing the injection hole. The second method is a method called an ODF (One Drop Fill) method. For example, an ultraviolet light curable 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 film faces, 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. can do. 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 crystals and smectic liquid crystals. Among them, nematic liquid crystals are preferable. For example, Schiff base liquid crystals, azoxy liquid crystals, biphenyl liquid crystals, phenylcyclohexane liquid crystals, ester liquid crystals, terphenyl liquid crystals, biphenyls. A cyclohexane liquid crystal, a pyrimidine liquid crystal, a dioxane liquid crystal, a bicyclooctane liquid crystal, a cubane liquid crystal, or the like can be used. Further, cholesteric liquid crystals such as cholestyl chloride, cholesteryl nonate, and cholesteryl carbonate; chiral agents such as those sold under the trade names “C-15” and “CB-15” (manufactured by Merck & Co., Inc.). A ferroelectric liquid crystal such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate may be added and used.

  And the liquid crystal display element of this invention can be obtained by bonding a polarizing plate on the outer surface of a liquid crystal cell. As a polarizing plate to be bonded to the outer surface of the liquid crystal cell, a polarizing film or an H film itself in which a polarizing film called an “H film” in which iodine is absorbed while stretching and aligning polyvinyl alcohol is sandwiched between cellulose acetate protective films The polarizing plate which consists of can be mentioned. 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 element of the present invention can be effectively applied to various devices, such as watches, portable games, word processors, notebook computers, car navigation systems, camcorders, PDAs, digital cameras, mobile phones, smartphones, 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

[Example 1]
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 16.24 g of this polyamic acid solution, 9.94 g of NMP and 6.54 g of diacetone alcohol (DAA) as a specific solvent (B) are added (NMP: DAA = 60: 40 (weight ratio)), and the polyamic acid concentration is 6. 0% by weight of a liquid crystal aligning agent (S1) was obtained.
[Examples 2 to 4 and Comparative Example 1]
Liquid crystal aligning agents (S2) to (S4) and (R1) were obtained in the same manner as in Example 1 except that the type of the second solvent used for preparing the liquid crystal aligning agent was changed as shown in Table 1 below.

[Example 5]
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), 336.4 g of diacetone alcohol (DAA) is added as a specific solvent (B) (NMP: DAA = 50: 50 (weight ratio)), and the polyamic acid concentration is 6. 0% by weight of a liquid crystal aligning agent (S5) was obtained.
[Examples 6 to 8 and Comparative Example 2]
Liquid crystal aligning agents (S6) to (S8) and (R2) were obtained in the same manner as in Example 5 except that the type of the second solvent used for preparing the liquid crystal aligning agent was changed as shown in Table 1 below.

[Example 9]
19.61 g (0.1 mol) of CBDA as tetracarboxylic dianhydride and 18.73 g (0.094 mol) of 4,4′-diaminodiphenylamine (4,4′DADPA) as diamine were mixed in 345.1 g of NMP. And allowed to react 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), 88.89 g of diacetone alcohol (DAA) is added as a specific solvent (B) (NMP: DAA = 80: 20 (weight ratio)), and the polyamic acid concentration is 6. 0% by weight of a liquid crystal aligning agent (S9) was obtained.
[Examples 10 to 12 and Comparative Example 3]
Liquid crystal aligning agents (S10) to (S12) and (R3) were obtained in the same manner as in Example 9 except that the type of solvent used for preparing the liquid crystal aligning agent was changed as shown in Table 1 below.

[Example 13]
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, 50 g of NMP and 20 g of diacetone alcohol (DAA) as a specific solvent (B) were added (NMP: DAA = 80: 20 (weight ratio)), and the mixture was sufficiently stirred to obtain a uniform solution with a concentration of 6.0 wt. % Liquid crystal aligning agent (S13) was obtained.
[Examples 14 to 16 and Comparative Example 4]
Liquid crystal aligning agents (S14) to (S16) and (R4) were obtained in the same manner as in Example 13 except that the type of the second solvent used for preparing the liquid crystal aligning agent was changed as shown in Table 1 below.

[Example 17]
1.46 g (13.5 mmol) of p-PDA as a diamine, and 1,3-diamino-4- {4- [trans-4- (trans-4-n-pentylcyclohexyl) cyclohexyl] phenoxy} benzene (PBCH5DAB, above 0.65 g (1.50 mmol) of the compound represented by the formula (d-4-2) is mixed in 20.0 g of NMP, and 2.85 g (14.5 mmol) of CBDA is added as a tetracarboxylic dianhydride. , 24.7 g of NMP was added and reacted at 25 ° C. for 5 hours to obtain a solution containing polyamic acid (PA-5). Next, 10.7 g of NMP and 16.0 g of diacetone alcohol (DAA) as a specific solvent (B) were added to 40.0 g of the obtained polyamic acid solution (NMP: DAA = 75: 25 (weight ratio)) and stirred for 1 hour. As a result, a liquid crystal aligning agent (S17) having a polyamic acid concentration of 6% by weight was obtained.
[Examples 18 to 20 and Comparative Example 5]
Liquid crystal aligning agents (S18) to (S20) and (R5) were obtained in the same manner as in Example 17 except that the type of the second solvent used for preparing the liquid crystal aligning agent was changed as shown in Table 1 below.

[Example 21]
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 prepared. Next, 75.8 g of diacetone alcohol (DAA) was added as a specific solvent (B) to the obtained NMP solution of polyamic acid (PA-6) (NMP: DAA = 35: 65 (weight ratio)), and the solid content A liquid crystal aligning agent (S21) having a concentration of 6.0% by weight was obtained.
[Examples 22 to 24 and Comparative Example 6]
Liquid crystal aligning agents (S22) to (S24) and (R6) were obtained in the same manner as in Example 21 except that the type of the second solvent used for preparing the liquid crystal aligning agent was changed as shown in Table 1 below.

[Example 25]
As the tetracarboxylic dianhydride, 8.724 g (0.04 mol) of pyromellitic dianhydride (PMDA), 2.877 g (0.0266 mol) of p-PDA and 4.567 g (0.012 mol) of PCH7DAB as NMP91 are obtained. 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, 20 g of NMP and 30 g of diacetone alcohol (DAA) as a specific solvent (B) are added (NMP: DAA = 60: 40 (weight ratio)) to obtain a polyamic acid having a solid content concentration of 5.0% by weight. An acid solution was prepared and used as a liquid crystal aligning agent (S25).
[Examples 26 to 28 and Comparative Example 7]
Liquid crystal aligning agents (S26) to (S28) and (R7) were obtained in the same manner as in Example 25 except that the type of the second solvent used for preparing the liquid crystal aligning agent was changed as shown in Table 1 below.

[Example 29]
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, 221.5 g of diacetone alcohol (DAA) was added as a specific solvent (B) (NMP: DAA = 60: 40 (weight ratio)), and the solid content concentration was 6.0% by weight. A liquid crystal aligning agent (S29) was obtained.
[Examples 30 to 32 and Comparative Example 8]
Liquid crystal aligning agents (S30) to (S32) and (R8) were obtained in the same manner as in Example 29 except that the type of the second solvent used for preparing the liquid crystal aligning agent was changed as shown in Table 1 below.

[Example 33]
Bicyclo [3,3,0] octane-2,4,6,8-tetracarboxylic dianhydride (BODA) 4.50 g (0.018 mol) as tetracarboxylic dianhydride and 0.68 g of PCH7DAB as diamine ( 0.0018 mol) and 1.75 g (0.0162 mol) of p-PDA were reacted 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. 0.6 g of this powder was dissolved in 4.7 g of NMP and 4.7 g of diacetone alcohol (DAA) as the specific solvent (B) (NMP: DAA = 50: 50 (weight ratio)), and the solid content concentration was 6.0 wt. % Liquid crystal aligning agent (S33) was obtained.
[Examples 34 to 36 and Comparative Example 9]
Liquid crystal aligning agents (S34) to (S36) and (R9) were obtained in the same manner as in Example 33 except that the type of the second solvent used for preparing the liquid crystal aligning agent was changed as shown in Table 1 below.

[Example 37]
Bicyclo [3,3,0] octane-2,4,6,8-tetracarboxylic dianhydride (BODA) 4.50 g (0.018 mol) as tetracarboxylic dianhydride, and PBCH5DAB 2.34 g as diamine ( 0.0054 mol) and 1.92 g (0.0126 mol) of 3,5-diaminobenzoic acid (35DAB) were reacted at room temperature in 26.3 g of NMP, and 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 diacetone alcohol (DAA) as the specific solvent (B), and polyamic acid A solution having a 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 (S37) 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: D1: DAA = 30: 20: 50 (weight ratio).
[Example 38]
The same as Example 37 except that the amount of PBCH5DAB used for the synthesis of the 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 37 was performed using the obtained polyamic acid solution, and the 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 diacetone alcohol (DAA) as the specific solvent (B), and polyamic acid A solution having a 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 (S38) 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: D2: DAA = 30: 30: 40 (weight ratio).

[Example 39]
A solution containing polyamic acid (PA-1) was prepared in the same manner as in Example 1. 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 diacetone alcohol (DAA) as the specific solvent (B) (D1: DAA = 60: 40 ( Weight ratio)), and a liquid crystal aligning agent (S39) having a solid content concentration of 6.0% by weight was obtained.
[Example 40]
A solution containing polyamic acid (PA-2) was prepared in the same manner as in Example 5. 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 diethylene glycol diethyl ether (DEDG) as the specific solvent (B) (D2: DEDG = 50: 50 ( Weight ratio)), and a liquid crystal aligning agent (S40) having a polyamic acid concentration of 6.0% by weight was obtained.

[Example 41]
A solution containing polyamic acid (PA-3) was prepared in the same manner as in Example 9. 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 diisopentyl ether (DIPE) as the specific solvent (B) (NMP: D1: DIPE = 40: 40: 20 (weight ratio)) and a liquid crystal aligning agent (S41) having a polyamic acid concentration of 6.0% by weight was obtained.
[Example 42]
A solution containing polyamic acid (PA-4) was prepared in the same manner as in Example 13. 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 propylene glycol diacetate (PG-AC) as the specific solvent (B) (NMP: D2: PG-AC = 40: 40: 20 (weight ratio)) and a liquid crystal aligning agent (S42) having a polyamic acid concentration of 6.0% by weight was obtained.

[Example 43]
In the same manner as in Example 17, a solution containing polyamic acid (PA-5) was prepared. 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 diacetone alcohol (DAA) as the specific solvent (B) (D1: DAA = 75: 25 ( Weight ratio)), and a liquid crystal aligning agent (S43) having a polyamic acid concentration of 6.0% by weight was obtained.
[Example 44]
A solution containing polyamic acid (PA-6) was prepared in the same manner as in Example 21 above. 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 diethylene glycol diethyl ether (DEDG) as the specific solvent (B) (D2: DEDG = 35: 65 ( Weight ratio)), and a liquid crystal aligning agent (S44) having a polyamic acid concentration of 6.0% by weight was obtained.

[Example 45]
In the same manner as in Example 25, a solution containing polyamic acid (PA-7) was prepared. 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 diisopentyl ether (DIPE) as the specific solvent (B) (NMP: D1: (DIPE = 30: 30: 40 (weight ratio)) and a polyamic acid concentration of 6.0% by weight were obtained as a liquid crystal aligning agent (S45).
[Example 46]
In the same manner as in Example 29, a solution containing the polyamic acid intermediate (PA-8) was prepared. 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 propylene glycol diacetate (PG-AC) as the specific solvent (B) (NMP: D2: PG-AC = 30: 30: 40 (weight ratio)) and a liquid crystal aligning agent (S46) having a polyamic acid concentration of 6.0% by weight was obtained.
[Example 47]
In the same manner as in Example 33, 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 diacetone alcohol (DAA) as the specific solvent (B) (D1: DAA = 50: 50 ( Weight ratio)), and a liquid crystal aligning agent (S47) having a solid concentration of 6.0% by weight was obtained.

Abbreviations in Table 1 and Table 2 are as follows.
(Diamine)
DA-1: 1,5-bis (4-aminophenoxy) pentane DA-2: 2,4-diamino-N, N-diallylaniline 35DAB: 3,5-diaminobenzoic acid (monoamine)
MA-1: n-dodecylamine (first solvent)
D1: 3-methoxy-N, N-dimethylpropionamide D2: 3-butoxy-N, N-dimethylpropionamide (second solvent)
DAA: diacetone alcohol DEDG: diethylene glycol diethyl ether DIPE: diisopentyl ether PG-AC: propylene glycol diacetate BC: butyl cellosolve (additive)
3-AMP: 3-aminomethylpyridine (compound represented by the above formula (c-1-16))
However, in Table 2, the numerical value in parentheses in the “additive” column is the compounding ratio (parts by weight) of the amino compound (C) with respect to 100 parts by weight of the total amount of the polymer components used for the preparation of the liquid crystal aligning agent. .

<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 check for the presence 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 above.

  As shown in Tables 1 and 2, all of the liquid crystal aligning agents of the examples had good storage stability when stored at low temperatures and good printability after storage at low temperatures. 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.

Claims (8)

Containing 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;
The polymer (A) is a polymer obtained by using a diamine containing at least one selected from the group consisting of compounds represented by the following formulas (d-1) to (d-4),
The solvent is viewed contains at least one type of a particular solvent (B) selected from the group consisting of compounds represented by each of the following formula (b-1) and Formula (b-3), substantially comprise butyl cellosolve Not a liquid crystal aligning agent.

(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 C1-12 linear or branched monovalent hydrocarbon group, R ⁴ is a hydrogen atom, or a monovalent hydrocarbon of 1 to 12 carbon atoms linear or branched A containing group, ^{R 5} and ^{R 6} are independently a hydrogen atom or a methyl group in. The formula ^{(d-4), X} 4 and ^{X 5} each independently represent a single bond, -O-, -COO- or -OCO-, wherein R ⁷ is an alkanediyl group having 1 to 3 carbon atoms, a is 0 or 1, b is an integer of 0 to 2, and c is 1 to 20. (It is an integer and k is 0 or 1. However, a and b are not 0 at the same time.)

(In formula (b-1), R ⁸ and R ¹⁰ are each independently a monovalent hydrocarbon group having 1 to 3 carbon atoms, and R ⁹ is an alkanediyl group having 2 to 5 carbon atoms . In formula (b-3), X ⁶ is —C (OH) R ^a — (wherein R ^a is a methyl group or an ethyl group), —CO— or —COO— * (wherein * is R a.) showing a bond to ^{12, R 12} is an alkyl group having 1 to 4 carbon atoms.) Containing 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;
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- 3 ),
The solvent is viewed contains at least one type of a particular solvent (B) of a compound represented by the following formula (b-2), it does not contain butyl cellosolve substantially liquid crystal alignment agent.

(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 C1-12 linear or branched monovalent hydrocarbon group, R ⁴ is a hydrogen atom, or a monovalent hydrocarbon of 1 to 12 carbon atoms linear or branched A containing group, ^{R 5} and ^{R 6} are independently a hydrogen atom or a methyl group.)

(In the formula (b-2), R ¹¹ is a monovalent group having one “—O—” between the carbon-carbon bonds of a linear or branched alkyl group having 3 to 5 carbon atoms, carbon It is a monovalent group formed by substituting at least one hydrogen atom of a linear or branched alkyl group of 3 to 5 with a hydroxyl group, or a branched alkyl group of 3 to 5 carbon atoms .) The liquid crystal aligning agent of Claim 1 or 2 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 at least selected from the group consisting of a compound represented by the following formula (t-1), 1,2,3,4-cyclobutanetetracarboxylic dianhydride and pyromellitic dianhydride. The liquid crystal aligning agent as described in any one of Claims 1-3 which is a polymer obtained using the tetracarboxylic dianhydride containing 1 type.

(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.)   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.