JP5720234B2 - 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 specifically, formed using a liquid crystal aligning agent used for obtaining a liquid crystal aligning film used for a long period of time and the liquid crystal aligning agent. The present invention relates to a liquid crystal alignment film and a liquid crystal display element.

  The liquid crystal display elements are roughly classified into a horizontal alignment type and a vertical alignment type depending on the alignment direction of the liquid crystal molecules when no voltage is applied. The horizontal alignment type is a TN (Twisted Nematic) type element or an IPS (In-Plane) type. A switching type element is known, and a vertical alignment type is a VA (vertical alignment) type element.

  The alignment control of liquid crystal molecules when no voltage is applied is performed using a liquid crystal alignment film. The liquid crystal alignment film can be obtained by applying a liquid crystal aligning agent containing polyimide or polyamic acid to a substrate and then baking it.

  In order to improve the display performance of the liquid crystal display element, it is necessary to appropriately control the alignment of liquid crystal molecules by the liquid crystal alignment film, and various liquid crystal alignment agents for producing a liquid crystal alignment film capable of realizing this are proposed. (For example, refer to Patent Document 1 and Patent Document 2).

  Patent Document 1 discloses a liquid crystal aligning agent containing a polyamic acid having a repeating unit having a phenylene group in the main chain and a repeating unit having a biphenylene group or the like in the main chain. Patent Document 2 discloses a liquid crystal aligning agent containing a polyamic acid or a polyimide having a hindered amine structure or a hindered phenol structure in the side chain. In these Patent Documents 1 and 2, by including the polyamic acid or polyimide having the above structure in the liquid crystal aligning agent, the alignment performance of the liquid crystal is maintained even after a long continuous use of the liquid crystal display element. To improve reliability.

JP 2004-94179 A JP 2010-244015 A

  Here, the liquid crystal display element is applied to a high-quality monitor such as a liquid crystal television. For such a high-quality monitor, not only the reliability for continuous use for a long time but also the voltage ON / OFF is repeatedly performed. Even when used for a long time, long-term durability that maintains the alignment performance of the liquid crystal is required. And the period in which this long-term durability is required is longer. On the other hand, it was found that those described in Patent Document 1 and those described in Patent Document 2 are insufficient in terms of long-term durability as described above.

  The present invention has been made in view of the above circumstances, and a liquid crystal aligning agent for obtaining a liquid crystal display element having long-term durability that maintains the alignment performance of liquid crystal even for long-term use, the liquid crystal A main object is to provide a liquid crystal alignment film formed of an alignment agent and a liquid crystal display device including the liquid crystal alignment film.

As a result of intensive studies to achieve the above-described problems of the prior art, the inventors of the present invention have a polymer having a repeating unit derived from an ethylenically unsaturated monomer, and the repeating unit is a specific polymer. by containing the polymer having repeating units of the cyclic amine structure, they found that it is possible solve the above problems, 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.

According to the present invention, a polymer having a repeating unit derived from an ethylenically unsaturated monomer is contained, and the repeating unit is represented by the following formula (S), wherein two carbon atoms adjacent to a nitrogen atom are each represented by the following formula (S): liquid crystal aligning agent characterized in that those having a cyclic amine structure having two substituents is provided that.

（式中、Ｒ^１１は、単結合又は置換されていてもよい炭化水素基であり、Ｘは、単結合、酸素原子、硫黄原子、−ＣＯ−、−ＣＯ−Ｏ−又は−Ｏ−ＣＯ−であり、Ｒ^１２は、置換されていてもよい炭化水素基である。但し、Ｘが単結合ではない場合、Ｒ^１１及びＲ^１２が互いに結合して環構造を形成していてもよい。）

(In the formula, R ¹¹ represents a single bond or an optionally substituted hydrocarbon group, and X represents a single bond, an oxygen atom, a sulfur atom, —CO—, —CO—O— or —O—CO—. R ¹² is an optionally substituted hydrocarbon group, provided that when X is not a single bond, R ¹¹ and R ¹² may be bonded to each other to form a ring structure.

According to the liquid crystal aligning agent of the present invention, by a repeating unit derived from an ethylenically unsaturated monomer has a polymer containing a repeating unit having the cyclic amine structure, using long-term In contrast, it is possible to obtain a liquid crystal display element having long-term durability that maintains the alignment performance of the liquid crystal.
The liquid crystal aligning agent is at least one polymer selected from the group consisting of polyamic acid obtained by reacting tetracarboxylic dianhydride and diamine and an imidized polymer thereof (hereinafter referred to as polymer [B]). (Also referred to as). Thereby, the improvement of the durability can be expected, and further the improvement of electrical characteristics such as the voltage holding ratio can be expected.

In the present invention, in order to suitably obtain the liquid crystal aligning agent capable of causing the long-term durability, the repeating unit is preferably a repeating unit represented by the following formula (1-1 ). The repeating unit represented by the following formula (1-1-1 ) is more preferable.

（式（１−１）中、Ｒは水素原子又はメチル基であり、Ａ^１は単結合又は２価の連結基であり、Ｒ^１１は、それぞれ、単結合又は置換されていてもよい炭化水素基であり、Ｘは、それぞれ、単結合、酸素原子、硫黄原子、−ＣＯ−、−ＣＯ−Ｏ−又は−Ｏ−ＣＯ−であり、Ｒ^１２は、それぞれ、置換されていてもよい炭化水素基である。但し、Ｘが単結合ではない場合、Ｒ^１１及びＲ^１２が互いに結合して環構造を形成していてもよい。式（１−１）中、Ｂ^１は、水素原子、酸素原子、ハロゲン原子、水酸基又は１価の有機基であり、ｍは０〜４の整数である。）

(In Formula (1-1 ) , R is a hydrogen atom or a methyl group, A ¹ is a single bond or a divalent linking group, and R ¹¹ is a single bond or an optionally substituted hydrocarbon, respectively. Each of X is a single bond, an oxygen atom, a sulfur atom, -CO-, -CO-O- or -O-CO-, and each of R ¹² is an optionally substituted hydrocarbon. Provided that when X is not a single bond, R ¹¹ and R ¹² may be bonded to each other to form a ring structure, wherein B ¹ is a hydrogen atom, oxygen An atom, a halogen atom, a hydroxyl group or a monovalent organic group, and m is an integer of 0 to 4. )

（式（１−１−１）中、Ｒは水素原子又はメチル基であり、Ａ^１は単結合又は２価の連結基であり、Ｒ^１３は、それぞれ、炭素数１〜５のアルキル基である。式（１−１−１）中、Ｂ^１は、水素原子、酸素原子、ハロゲン原子、水酸基又は１価の有機基である。）

(In Formula (1-1-1 ) , R is a hydrogen atom or a methyl group, A ¹ is a single bond or a divalent linking group, and R ¹³ is an alkyl group having 1 to 5 carbon atoms, respectively. In formula (1-1-1), B ¹ is a hydrogen atom, an oxygen atom, a halogen atom, a hydroxyl group or a monovalent organic group.

Moreover, in this invention, it is preferable that the polymer containing the repeating unit which has the said cyclic amine structure further has a repeating unit represented by following formula (2).

（式（２）中、Ｒ^２は水素原子又はメチル基であり、Ａ^２は単結合又は２価の連結基であり、Ｂ^２はステロイド骨格を有する炭素数１７〜３０の１価の有機基、トコフェロール構造を有する１価の有機基、又は下記式（Ｂ２）で表される１価の有機基である。

(In Formula (2), R ² is a hydrogen atom or a methyl group, A ² is a single bond or a divalent linking group, and B ² is a monovalent organic group having 17 to 30 carbon atoms and having a steroid skeleton. , A monovalent organic group having a tocopherol structure, or a monovalent organic group represented by the following formula (B2).

（Ｂ^２１は、シクロヘキシレン基であるか、又は置換若しくは無置換のフェニレン基であり、Ｂ^２２は水素原子又は炭素数１〜３０のアルキル基である。ｋは０〜３の整数である。但し、Ｂ^２２が水素原子である場合、ｋは１以上である。また、ｋが２又は３の場合、複数のＢ^２１はそれぞれ独立して上記定義を有する。「＊」はＡ^２に結合する結合手を示す。））

(B ²¹ is a cyclohexylene group, or a substituted or unsubstituted phenylene group, B ²² is a hydrogen atom or an alkyl group having 1 to 30 carbon atoms, and k is an integer of 0 to 3. However, when B ²² is a hydrogen atom, k is 1 or more, and when k is 2 or 3, a plurality of B ²¹ each independently has the above definition, “*” is bonded to A ² Shows the bonding hand to perform.))

  In this case, the pretilt angle can be further improved while prolonging the durability.

  Moreover, according to this invention, the liquid crystal aligning film formed with the said liquid crystal aligning agent and the liquid crystal display element which comprises the said liquid crystal aligning film are provided. These liquid crystal alignment films and liquid crystal display elements can be suitably used particularly for VA liquid crystal display elements.

  In the present specification, the “hydrocarbon group” includes a chain hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. The “hydrocarbon group” may be a saturated hydrocarbon group or an unsaturated hydrocarbon group.

  The “chain hydrocarbon group” means a hydrocarbon group composed only of a chain structure, and may be linear or branched. The “alicyclic hydrocarbon group” means a hydrocarbon 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 constituted only by the structure of the alicyclic hydrocarbon, and a part thereof may include a chain structure. “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.

  In the present specification, “(meth) acryl” means acryl and methacryl, and “(meth) acryloyl” means acryloyl and methacryloyl.

  The liquid crystal aligning agent of this invention contains the polymer [A] which has a repeating unit derived from an ethylenically unsaturated monomer. Hereinafter, the liquid crystal aligning agent of this invention is demonstrated in detail.

<Polymer [A]>
[Repeating unit (a1)]
The polymer [A] in the present invention is
A cyclic amine structure in which two carbon atoms adjacent to the nitrogen atom each have two substituents represented by the following formula (S), or at least one carbon atom in the ortho position relative to the hydroxyl group is It has a repeating unit (a1) having a phenol structure having a substituent represented by the following formula (S).

（式中、Ｒ^１１は、単結合又は置換されていてもよい炭化水素基であり、Ｘは、単結合、酸素原子、硫黄原子、−ＣＯ−、−ＣＯ−Ｏ−又は−Ｏ−ＣＯ−であり、Ｒ^１２は、置換されていてもよい炭化水素基である。但し、Ｘが単結合ではない場合、Ｒ^１１及びＲ^１２が互いに結合して環構造を形成していてもよい。）

(In the formula, R ¹¹ represents a single bond or an optionally substituted hydrocarbon group, and X represents a single bond, an oxygen atom, a sulfur atom, —CO—, —CO—O— or —O—CO—. R ¹² is an optionally substituted hydrocarbon group, provided that when X is not a single bond, R ¹¹ and R ¹² may be bonded to each other to form a ring structure.

  As said cyclic amine structure, it is preferable that the number of the carbon atoms which form the ring structure is 2-7, More preferably, it is five. Moreover, as said phenol structure, although the position which a hydroxyl group couple | bonds in a benzene ring is arbitrary, Preferably it is a para-position with respect to the carbon atom couple | bonded with the principal chain side in the said benzene ring.

  More specifically, the preferred structure of the repeating unit (a1) is a structure represented by the following formula (1-1) having a hindered amine structure when it has a cyclic amine structure. On the other hand, when it has a phenol structure, it has a hindered phenol structure and is a structure represented by the following formula (1-2).

（式（１−１）及び式（１−２）中、Ｒは水素原子又はメチル基であり、Ａ^１は単結合又は２価の連結基であり、式（１−１）中、Ｂ^１は、水素原子、酸素原子、ハロゲン原子、水酸基又は１価の有機基であり、ｍは０〜４の整数である。式（１−２）中、ｎは０〜３の整数である。Ｒ^１１、Ｘ及びＲ^１２の定義は、上記式（Ｓ）と同じである。）

(In Formula (1-1) and Formula (1-2), R is a hydrogen atom or a methyl group, A ¹ is a single bond or a divalent linking group, and B ^{1 in} Formula (1-1) Is a hydrogen atom, an oxygen atom, a halogen atom, a hydroxyl group or a monovalent organic group, and m is an integer of 0 to 4. In formula (1-2), n is an integer of 0 to 3. R ¹¹ , X and R ^{12 have} the same definition as in the above formula (S).)

In the above formula (S), the above formula (1-1), and the above formula (1-2), specifically, as the hydrocarbon group of R ^11, a divalent chain hydrocarbon group having 1 to 10 carbon atoms, Examples thereof include a divalent alicyclic hydrocarbon group having 3 to 15 carbon atoms and a divalent aromatic hydrocarbon group having 6 to 20 carbon atoms. Of these, a methylene group or an alkylene group having 2 to 5 carbon atoms is preferable. Specific examples of the alkylene group having 2 to 5 carbon atoms include an ethylene group, a propylene group, a butylene group, and a pentylene group, and these may be either linear or branched. Examples of the substituent that the hydrocarbon group may have include a halogen atom such as a fluorine atom or a chlorine atom, a hydroxyl group, and the like.

In the above formula (S), the above formula (1-1) and the above formula (1-2), when —R ¹¹ —X— is not a single bond, preferably —CO—O—, —CH ₂ —CO -, or _-CH 2 -CH (OH) - it is.

In the above formula (S), the above formula (1-1), and the above formula (1-2), R ¹² is specifically an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or carbon. The aralkyl group of several 7-13 can be mentioned. In this case, the hydrogen atom of the benzene ring of the aryl group and the aralkyl group may be substituted with a formyl group or an alkoxy group having 1 to 4 carbon atoms.

Examples of the alkyl group having 1 to 6 carbon atoms of R ¹² include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a 2-butyl group, an i-butyl group, and a t-butyl group. Etc .;
Examples of the aryl group having 6 to 12 carbon atoms include a phenyl group, 4-formylphenyl group, 3,4,5-trimethoxyphenyl group and the like;
Examples of the aralkyl group having 7 to 13 carbon atoms include a benzyl group.
Examples of the ring structure formed by combining R ¹¹ and R ¹² with each other include groups in which one hydrogen atom has been removed from furan, thiophene, 2H-pyran, 4H-pyran, and the like.

The formula (S), the formula (1-1) and the formula (1-2) is ^preferably an -R 11 ^{-X-R 12,} for example a methyl group, an ethyl group, n- propyl group, i- propyl Group, n-butyl group, 2-butyl group, i-butyl group, t-butyl group, phenyl group, benzyl group, benzoyl group, 4-formylbenzoyl group, 2-hydroxy-2-phenylethyl group, 2-oxo -2- (3,4,5-trimethoxyphenyl) ethyl group and the like can be mentioned. -R ¹¹ -XR ¹² is more preferably an alkyl group having 1 to 5 carbon atoms, and in the case of the above formula (1-1), a methyl group or an ethyl group is particularly preferable, and the above formula (1- In the case of 2), a methyl group or a t-butyl group is particularly preferable.

In the above formula (1-1), m is preferably 0, and in the above formula (1-2), n is preferably 0 or 1. In the relationship with m and n and the relationship with -R ¹¹ -XR ¹² , the formula (1-1) and the formula (1-2) are preferably the following formulas (1-1-1). ) And the following formula (1-2-1).

（式（１−１−１）及び式（１−２−１）中、Ｒ^１３は、それぞれ、炭素数１〜５のアルキル基であり、式（１−２−１）中、Ｒ^１４は、水素原子又は炭素数１〜５のアルキル基である。Ｒ、Ａ^１、及びＢ^１の定義は、上記式（１−１）及び上記式（１−２）と同じである。）

(In Formula (1-1-1) and Formula (1-2-1), R ¹³ is an alkyl group having 1 to 5 carbon atoms, and in Formula (1-2-1), R ¹⁴ is , A hydrogen atom or an alkyl group having 1 to 5 carbon atoms, the definitions of R, A ¹ and B ¹ are the same as those in the above formula (1-1) and the above formula (1-2).

In Formula (1-1), Formula (1-2), Formula (1-1-1), and Formula (1-2-1), A ¹ is preferably a divalent linking group. As the divalent linking group represented by A ^1, it may include those represented by the following formula (A1).

（式中、Ａ^１１は、単結合、メチレン基、炭素数２〜５のアルキレン基、又はフェニレン基であり、Ａ^１２は、単結合、−Ｏ−、−ＣＯ−、−ＣＯ−Ｏ−、又は−Ｏ−ＣＯ−であり、Ａ^１３は、単結合であるか、又は置換されていてもよいメチレン基若しくは炭素数２〜５のアルキレン基であり、Ａ^１４は、単結合、−Ｏ−、−ＣＯ−、−ＣＯ−Ｏ−、−Ｏ−ＣＯ−、−ＮＲ’−、又は−ＮＲ’−ＣＯ−Ｏ−であり、Ｒ’は水素原子又は炭素数１〜６のアルキル基である。但し、Ａ^１１、Ａ^１２、Ａ^１３及びＡ^１４の全てが単結合であるものを除く。＊１は、環状アミン構造の炭素原子又はフェノール構造の炭素原子に結合する結合手を示す。）

(In the formula, A ¹¹ is a single bond, a methylene group, an alkylene group having 2 to 5 carbon atoms, or a phenylene group, and A ¹² is a single bond, —O—, —CO—, —CO—O—, Or -O-CO-, A ¹³ is a single bond or an optionally substituted methylene group or an alkylene group having 2 to 5 carbon atoms, A ¹⁴ is a single bond, -O- , —CO—, —CO—O—, —O—CO—, —NR′—, or —NR′—CO—O—, wherein R ′ is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. (However, all of A ¹¹ , A ¹² , A ¹³ and A ¹⁴ are single bonds. * 1 represents a bond bonded to a carbon atom of a cyclic amine structure or a carbon atom of a phenol structure.)

In the formula ^(A1), the alkylene group having 2 to 5 carbon atoms ^{A 11} and ^{A 13,} can be referred to the ones as exemplified for the above ^{R 11.} As the methylene group or substituent which may be possessed by the alkylene group having 2 to 5 carbon atoms A ^13, it can be referred to the ones as exemplified for the above R ^11. The alkyl group having 1 to 6 carbon atoms R ', may be the ones as exemplified for the above R ^12.

  Examples of the divalent linking group represented by the formula (A1) include the following.

（式（Ａ１−１）〜式（Ａ１−１７）中、＊１は、環状アミン構造の炭素原子又はフェノール構造の炭素原子に結合する結合手を示す。）

(In formula (A1-1) to formula (A1-17), * 1 represents a bond bonded to a carbon atom of a cyclic amine structure or a carbon atom of a phenol structure.)

In the above formulas (A1-1) to (A1-17), in order to suitably improve the durability of the obtained liquid crystal alignment film, the divalent linking group for A ¹ is preferably represented by the formula (A1-2). ), Formula (A1-5), Formula (A1-8), Formula (A1-10), Formula (A1-11), Formula (A1-16), and Formula (A1-17). More preferably, it is represented by any one of formula (A1-2), formula (A1-5) and formula (A1-10).

In the formula (1-1) and the formula (1-1-1), examples of the halogen atom for B ¹ include a fluorine atom and a chlorine atom.

In the above formula (1-1) and the above formula (1-1-1), examples of the monovalent organic group for B ¹ include those represented by the following formula (B1).

（式中、Ｂ^１１は、単結合、−Ｏ−、−ＣＯ−、−ＣＯ−Ｏ−、−Ｏ−ＣＯ−、−Ｏ−ＣＯ−ＮＲ’’−、又は−ＣＯ−ＮＲ’’−であり、Ｒ’’は水素原子又は炭素数１〜６のアルキル基である。Ｂ^１２は、炭素数１〜１５のアルキル基、炭素数６〜１２のアリール基、炭素数７〜１３のアラルキル基、炭素数３〜１０の１価の複素環基、又は炭素数３〜１５の脂環式炭化水素基であって、これらの基が有する水素原子が置換されていてもよい。）

(Wherein B ¹¹ is a single bond, —O—, —CO—, —CO—O—, —O—CO—, —O—CO—NR ″ —, or —CO—NR ″ —. R ″ is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. B ¹² is an alkyl group having 1 to 15 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an aralkyl group having 7 to 13 carbon atoms. And a monovalent heterocyclic group having 3 to 10 carbon atoms or an alicyclic hydrocarbon group having 3 to 15 carbon atoms, and the hydrogen atom of these groups may be substituted.)

In the above formula (B1), the alkyl group having 1 to 6 carbon atoms R '', may be the ones as exemplified for the above R ^12.

In the above formula (B1), the alkyl group having 1 to 15 carbon atoms of B ¹² may be linear or branched. For example, a methyl group, an ethyl group, a propyl group, a butyl group, A pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group and the like;
Examples of the aryl group having 6 to 12 carbon atoms include phenyl group, tolyl group, 4-ethylphenyl group, dimethylphenyl group, 2,4,6-trimethylphenyl group, naphthyl group, anthryl group;
Examples of the aralkyl group having 7 to 13 carbon atoms include benzyl group, phenethyl group, α-methylbenzyl group, naphthylmethyl group and the like;
Examples of the monovalent heterocyclic group having 3 to 10 carbon atoms include nitrogen-containing heterocyclic compounds, such as piperidine, morpholine, pyridine, pyrazine and the like;
Examples of the alicyclic hydrocarbon group having 3 to 15 carbon atoms include a cyclopentyl group, a cyclohexyl group, a 4-methylcyclohexyl group, and the like.

In addition, examples of the substituent that each group of B ¹² may have include a halogen atom such as a fluorine atom and a chlorine atom, a hydroxyl group, a nitro group, and a cyano group.

Examples of the monovalent organic group (—B ¹¹ —B ¹² ) represented by the above formula (B1) include, for example, a methyl group, an n-butyl group, an n-pentyl group, a t-pentyl group, an n-octyl group, Benzyl group, 4-ethylphenyl group, 4-methylcyclohexyl group, methoxy group, octyloxy group, cyclohexyloxy group, acetyl group, acetyloxy group, tetradecanoyl group, α-methylbenzyloxy group, piperidinocarbonyl Group, morpholinocarbonyl group, 2-hydroxy-2-methylpropoxy group, —O—CONH—C ₆ H _{5 and the} like.

In the above formula (1-1) and the above formula (1-1-1), B ¹ is preferably a hydrogen atom, an oxygen atom, or a chlorine atom in order to suitably improve the durability of the obtained liquid crystal alignment film. , Methyl group, n-butyl group, n-pentyl group, t-pentyl group, benzyl group, methoxy group, octyloxy group, acetyl group, acetyloxy group, cyclohexyloxy group, more preferably hydrogen. An atom, an oxygen atom, a methyl group, a benzyl group, or an octyloxy group.

  Specific examples of the repeating unit (a1) having a hindered amine structure include those represented by the following formulas (a1-1-1) to (a1-1-20).

（式中、Ｒは水素原子又はメチル基である。）

(In the formula, R is a hydrogen atom or a methyl group.)

The monomer which gives the hindered amine structure repeating unit (a1) can be easily synthesized by combining organic chemistry methods. For example, if it is a monomer which gives the repeating unit of the above formula (a1-1-1) to formula (a1-1-16), it is represented by halogenated (meth) acryloyl and the following formula (C-1). Can be obtained according to a known esterification reaction. Moreover, if it is a monomer which gives the repeating unit of the said Formula (a1-1-17) or Formula (a1-1-18), halogenated 2-propenyl or halogenated 9-decyl, and following formula (C- It can be obtained by reacting the compound represented by 1) according to a known etherification reaction. Moreover, if it is a monomer which gives the repeating unit of the said formula (a1-1-19) or a formula (a1-1-20), halogenated (meth) acryloyl and the following formula (C-1), OH- It can be obtained by reacting a compound in which A ¹³ -A ^14- is replaced with NH _2- according to a known amidation reaction.

（式中、Ａ^１３、Ａ^１４、Ｂ^１及びＲ^１３の定義は、既に説明したものと同じである。）

(In the formula, the definitions of A ¹³ , A ¹⁴ , B ¹ and R ¹³ are the same as those already described.)

  Moreover, a commercially available thing can also be used for each said monomer, for example, methacrylic acid 2,2,6,6-tetramethyl-4-piperidyl and methacrylic acid 1,2,2,6,6- Pentamethyl-4-piperidyl is commercially available from Hitachi Chemical Co., Ltd. as FA-712HM and FA-711MM, respectively.

  Specific examples of the repeating unit (a1) having a hindered phenol structure include those represented by the following formulas (a1-2-1) to (a1-2-10).

（式中、Ｒは水素原子又はメチル基である。）

(In the formula, R is a hydrogen atom or a methyl group.)

  The monomer that gives the hindered phenol structure repeating unit (a1) can be easily synthesized by combining organic chemistry methods.

  The repeating unit (a1) preferably has a hindered amine structure rather than a hindered phenol structure in order to improve the durability of the obtained liquid crystal alignment film.

  The polymer [A] may have the repeating unit (a1) alone or in combination of two or more. Although the mechanism is not clear, since the polymer [A] has the repeating unit (a1), the ultraviolet ray irradiated from the backlight or the like is suitably absorbed by the polymer [A], and the ultraviolet ray It is presumed that the influence of is difficult to reach at least one polymer selected from the group consisting of a polyamic acid obtained by reacting tetracarboxylic dianhydride and diamine and an imidized polymer thereof. As a result, the alignment performance of the liquid crystal can be maintained even for long-term use, and a liquid crystal display element having long-term durability can be obtained. In addition, the content ratio of the repeating unit (a1) in the polymer [A] (or the copolymerization ratio of the monomer giving the repeating unit (a1)) for enhancing the effect is the total weight of the polymer [A]. (Or the total weight of monomers used in the synthesis of the polymer [A]) is preferably 1% by weight or more, more preferably 1% by weight or more and 50% by weight or less, and still more preferably Is 1% by weight or more and 30% by weight or less, and particularly preferably 1% by weight or more and 20% by weight or less.

<Other repeating units>
The polymer [A] preferably has the following repeating unit (a2) as a repeating unit other than the repeating unit (a1), and further includes the repeating units (a3) to (a7) shown below. It is preferable to have at least one of them.

[Repeating unit (a2)]
The repeating unit (a2) has at least one of a cyclohexane structure and a benzene ring structure. Specifically, examples of the repeating unit (a2) include a repeating unit represented by the following general formula (2).

（式（２）中、Ｒ^２は水素原子又はメチル基であり、Ａ^２は単結合又は２価の連結基であり、Ｂ^２はステロイド骨格を有する炭素数１７〜３０の１価の有機基、トコフェロール構造を有する１価の有機基、又は下記式（Ｂ２）で表される１価の有機基である。

(In Formula (2), R ² is a hydrogen atom or a methyl group, A ² is a single bond or a divalent linking group, and B ² is a monovalent organic group having 17 to 30 carbon atoms and having a steroid skeleton. , A monovalent organic group having a tocopherol structure, or a monovalent organic group represented by the following formula (B2).

（Ｂ^２１は、シクロヘキシレン基であるか、又は置換若しくは無置換のフェニレン基であり、Ｂ^２２は水素原子又は炭素数１〜３０のアルキル基である。ｋは０〜３の整数である。但し、Ｂ^２２が水素原子である場合、ｋは１以上である。また、ｋが２又は３の場合、複数のＢ^２１はそれぞれ独立して上記定義を有する。「＊」はＡ^２に結合する結合手を示す。））

(B ²¹ is a cyclohexylene group, or a substituted or unsubstituted phenylene group, B ²² is a hydrogen atom or an alkyl group having 1 to 30 carbon atoms, and k is an integer of 0 to 3. However, when B ²² is a hydrogen atom, k is 1 or more, and when k is 2 or 3, a plurality of B ²¹ each independently has the above definition, “*” is bonded to A ² Shows the bonding hand to perform.))

In the above formula (2), examples of the divalent linking group for A ² include a phenylene group, and those represented by any of the following formulas (A2-1) to (A2-6). .

（上記式中のｐは０又は２であり、ｑは０又は１であり、ｒ及びｓはそれぞれ１〜６の整数であり、「＊２」はＢ^２と結合する結合手を示す。）

(In the above formula, p is 0 or 2, q is 0 or 1, r and s are each an integer of 1 to 6, and “* 2” represents a bond that binds to B ^2. )

A ² is preferably a single bond.
In the above formula (2), examples of the monovalent organic group having 17 to 30 carbon atoms and having a steroid skeleton of B ² include cholestane-3-yl group, cholesta-5-en-3-yl group, and cholesta- Examples thereof include a 24-ene-3-yl group, a cholesta-5,24-dien-3-yl group, and a lanostane-3-yl group.

In the above formula (B2), examples of the substituent of the phenylene group of B ²¹ include those enumerated above for B ¹² and preferably a fluorine atom. Examples of the alkyl group having 1 to 30 carbon atoms of B ²² include icosyl group, pentacosyl group, and triacontyl group in addition to those listed as the alkyl group having 1 to 15 carbon atoms of B ^12. .
The monovalent organic group represented by the formula (B2) is preferably a cyclohexyl group having an alkyl group having 4 to 8 carbon atoms, an alkyl group having 3 to 30 carbon atoms, a difluorophenyl group, a trifluoromethylphenyl group, A trifluoromethoxyphenyl group or a group represented by the following formula (B2-1) can be exemplified.

（式中、ｋ１は１又は２であり、Ｂ^２２の定義は上記式（Ｂ２）と同じである。）

(Wherein, k1 is 1 or ^2, the definition of ^{B 22} is the same as the above formula (B2).)

In this case, 2 is preferable as ^k1, as the ^{B 22} is preferably an alkyl group having 1 to 6 carbon atoms. The group represented by the formula (B2-1) is particularly preferably a 4- (4′-pentylbicyclohexyl-4-yl) phenyl group.

B ² includes a monovalent organic group having 17 to 30 carbon atoms having a steroid skeleton, a monovalent organic group having a tocopherol structure, a cyclohexyl group having an alkyl group having 4 to 8 carbon atoms, or the above formula (B2- The group represented by 1) is preferred.

  The repeating unit (a2) is preferably a repeating unit obtained from each monomer such as cholestanyl methacrylate, 4- (4'-pentylbicyclohexyl-4-yl) phenyl methacrylate, and tocopherol methacrylate.

Incidentally, the monomer giving the repeating unit (a2), for example, a halide and (meth) acryloyl compound B ² -A 2 ^-OH, can be obtained by reacting according to known esterification reactions.

  The polymer [A] may have the repeating unit (a2) alone or in combination of two or more. When the polymer [A] has the repeating unit (a2), the pretilt angle stability can be improved, and the liquid crystal alignment can be further improved. Further, the content ratio of the repeating unit (a2) in the polymer [A] for enhancing the effect (or the copolymerization ratio of the monomer giving the repeating unit (a2)) is the total weight of the polymer [A]. (Or the total weight of monomers used in the synthesis of the polymer [A]) is preferably 60% by weight or less, more preferably 1% by weight or more and 60% by weight or less, and still more preferably It is 2 to 40% by weight.

[Repeating unit (a3)]
The repeating unit (a3) has a cyclic ether structure that enables a thermal crosslinking reaction. Specifically, examples of the repeating unit (a3) include a repeating unit represented by the following general formula (3).

（式（３）中、Ｒ^３は水素原子又はメチル基であり、Ａ^３は単結合、メチレン基又は炭素数２〜１０のアルキレン基であり、Ｂ^３は炭素数２〜１０の環状エーテル構造を有する基である。）

(In Formula (3), R ³ is a hydrogen atom or a methyl group, A ³ is a single bond, a methylene group or an alkylene group having 2 to 10 carbon atoms, and B ³ is a cyclic ether structure having 2 to 10 carbon atoms. A group having

Examples of the alkylene group having 2 to 10 carbon atoms of A ³ in the above formula (3) include hexylene group, heptylene group, decylene group and the like in addition to those listed for R ¹¹ above.
The cyclic ether structure having 2 to 10 carbon atoms of B ³ in the above formula (3) is preferably a 1,2-epoxy structure or a 1,3-epoxy structure having thermal crosslinking reactivity, and is excellent in reactivity. A 1,2-epoxy structure is more preferred.

The repeating unit (a3) is preferably a repeating unit in which A ³ is a methylene group or an alkylene group having 2 to 10 carbon atoms and B ³ is a group having a 1,2-epoxy structure in the above formula (3). A repeating unit in which A ³ is a methylene group or an alkylene group having 2 or 5 carbon atoms and B ³ is a group having a 1,2-epoxy structure is more preferable.

  The repeating unit (a3) is preferably glycidyl (meth) acrylate, (meth) acrylic acid-3,4-epoxybutyl, (meth) acrylic acid-6,7-epoxyheptyl, α-ethylacrylic acid-6, A repeating unit obtained by each monomer such as 7-epoxyheptyl is preferable. Among these, glycidyl (meth) acrylate is preferable in that the obtained liquid crystal alignment film has a high film density and can exhibit excellent electrical properties. The obtained repeating unit is more preferred.

  Polymer [A] may have a repeating unit (a3) individually by 1 type, and may have it in combination of 2 or more type. Since the polymer [A] has a repeating unit (a3), a thermal crosslinking reaction is performed by applying a liquid crystal aligning agent of the present invention to form a coating film, followed by heat treatment (post-baking), Thereby, the heat resistance, liquid crystal resistance (solvent resistance), and film density of the liquid crystal alignment film obtained can be further improved. Furthermore, diffusion of impurity ions contained in the liquid crystal into the liquid crystal alignment film can be further reduced. Due to these effects, even if heat stress is applied to the obtained liquid crystal display element or the liquid crystal panel is driven for a long time, the problem of the decrease in voltage holding ratio and image sticking is more reliably solved. A liquid crystal aligning agent that provides an alignment film can be obtained. Further, the content ratio of the repeating unit (a3) in the polymer [A] for enhancing the effect (or the copolymerization ratio of the monomer giving the repeating unit (a3)) is the total weight of the polymer [A]. (Or the total weight of monomers used in the synthesis of the polymer [A]) is preferably 50% by weight or less, more preferably 5% by weight or more and 50% by weight or less, and still more preferably Is 15% by weight or more and 45% by weight or less, and particularly preferably 20% by weight or more and 40% by weight or less.

[Repeating unit (a4)]
The repeating unit (a4) has a carboxyl group, and specifically includes a repeating unit represented by the following general formula (4).

（式（４）中、Ｒ^４１は水素原子、メチル基又はカルボキシメチル基であり、Ｒ^４２は水素原子、メチル基又はカルボキシル基である。但し、Ｒ^４１がカルボキシメチル基である場合、Ｒ^４２は水素原子又はメチル基である。）

(In the formula (4), R ⁴¹ is a hydrogen atom, a methyl group or a carboxymethyl group, and R ⁴² is a hydrogen atom, a methyl group or a carboxyl group, provided that when R ⁴¹ is a carboxymethyl group, R ⁴² Is a hydrogen atom or a methyl group.)

  Examples of the repeating unit (a4) include repeating units obtained from monomers such as maleic acid, fumaric acid, citraconic acid, mesaconic acid, itaconic acid, (meth) acrylic acid, and crotonic acid. Among these, in order to increase the compatibility of the polymer [A] with respect to the polyamic acid and its imidized polymer, and to increase the film density of the obtained liquid crystal alignment film, and to express a high degree of reliability with respect to electrical characteristics, A repeating unit obtained by (meth) acrylic acid is preferred.

  Polymer [A] may have a repeating unit (a4) individually by 1 type, and may have it in combination of 2 or more type. In the case where the polymer [A] has the repeating unit (a4), the liquid crystal aligning agent contains at least one polymer selected from the group consisting of polyamic acid and its imidized polymer. The compatibility of the polymer [A] with the polymer can be improved. Further, when the polymer [A] has the repeating unit (a3), it further has the repeating unit (a4) to promote the crosslinking reaction of the cyclic ether structure of the repeating unit (a3). Can do. Further, the content ratio of the repeating unit (a4) in the polymer [A] for enhancing the effect (or the copolymerization ratio of the monomer giving the repeating unit (a4)) is the total weight of the polymer [A]. (Or the total weight of monomers used in the synthesis of the polymer [A]) is preferably 50% by weight or less, more preferably 1% by weight or more and 40% by weight or less, and still more preferably 1% by weight or more and 30% by weight or less.

[Repeating unit (a5)]
The repeating unit (a5) has a maleimide structure, and specifically includes a repeating unit represented by the following general formula (5).

（式（５）中、Ａ^５は単結合、酸素原子若しくは硫黄原子であるか、又は酸素原子、硫黄原子、窒素原子若しくはケイ素原子を含む二価の基であり、Ｂ^５は炭素数６〜３０のアリール基又は炭素数４〜１０の脂環式基である。）

(In the formula (5), A ⁵ is a divalent group comprising a single bond, or an oxygen atom or a sulfur atom, or an oxygen atom, a sulfur atom, a nitrogen atom or a silicon atom, B ⁵ is 6 carbon atoms 30 aryl groups or alicyclic groups having 4 to 10 carbon atoms.)

In the above formula (5), A ⁵ is preferably a single bond.
In the above formula (5), examples of the aryl group having 6 to 30 carbon atoms of B ⁵ include a phenyl group, a naphthyl group, an anthracenyl group, a fluorenyl group and the like;
Examples of the alicyclic group having 4 to 10 carbon atoms include a cyclopentyl group and a cyclohexyl group, and a phenyl group or a cyclohexyl group is particularly preferable.

  As the repeating unit (a5), for example, N-phenylmaleimide, N-naphthylmaleimide, N-anthracenylmaleimide, N-fluorenylmaleimide, N-cyclopentylmaleimide, N-cyclohexylmaleimide, etc. The repeating unit obtained can be mentioned, Among these, the repeating unit obtained by N-phenylmaleimide or N-cyclohexylmaleimide is preferable.

  Polymer [A] may have a repeating unit (a5) individually by 1 type, and may have it in combination of 2 or more type. When the polymer [A] has the repeating unit (a5), the heat resistance of the obtained liquid crystal alignment film can be further improved. Further, the content ratio of the repeating unit (a5) in the polymer [A] (or the copolymerization ratio of the monomer giving the repeating unit (a5)) in enhancing the effect is the total weight of the polymer [A]. (Or the total weight of monomers used in synthesizing the polymer [A]) is preferably 20% by weight or less, more preferably 1% by weight or more and 15% by weight or less, and still more preferably 1% by weight or more and 10% by weight or less.

[Repeating unit (a6)]
The repeating unit (a6) is specifically represented by the following general formula (6).

（式（６）中、Ｒ^６は水素原子又はメチル基であり、Ａ^６は単結合、酸素原子若しくは硫黄原子であるか、又は酸素原子、硫黄原子、窒素原子若しくはケイ素原子を含む二価の基であり、Ｂ^６は水素原子、炭素数１〜２０のアルキル基又は炭素数６〜３０のアリール基である。）

(In formula (6), R ⁶ is a hydrogen atom or a methyl group, A ⁶ is a single bond, an oxygen atom or a sulfur atom, or a divalent atom containing an oxygen atom, a sulfur atom, a nitrogen atom or a silicon atom. B ⁶ is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 30 carbon atoms.)

In the above formula (6), A ⁶ is preferably a single bond.
In the above formula (6), the alkyl group having 1 to 20 carbon atoms ^{B 6,} such as methyl group, ethyl group, n- propyl group, n- butyl group, n- pentyl group, n- hexyl, n- A heptyl group, an n-octyl group and the like;
Examples of the aryl group having 6 to 30 carbon atoms include a phenyl group, a 4-biphenyl group, a 2-biphenyl group, a 1-naphthalenyl group, and a 2-naphthalenyl group. Of these, a phenyl group is preferable.

  Examples of the repeating unit (a6) include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene and other α-olefins, styrene, 4 -The repeating unit obtained by each monomer such as vinylbiphenyl, 2-vinylbiphenyl, 1-vinylnaphthalene, 2-vinylnaphthalene, α-methylstyrene, etc., among these, the repeating unit obtained by styrene Is preferred.

  Polymer [A] may have a repeating unit (a6) individually by 1 type, and may have it in combination of 2 or more type. When the polymer [A] has the repeating unit (a6), the heat resistance of the obtained liquid crystal alignment film can be further improved. Further, the content ratio of the repeating unit (a6) in the polymer [A] (or the copolymerization ratio of the monomer giving the repeating unit (a6)) for enhancing the effect is the total weight of the polymer [A]. (Or the total weight of monomers used in synthesizing the polymer [A]) is preferably 20% by weight or less, more preferably 1% by weight or more and 15% by weight or less, and still more preferably 1% by weight or more and 10% by weight or less.

[Repeating unit (a7)]
The repeating unit (a7) has a hydroxyl group, and specific examples include a repeating unit represented by the following general formula (7).

（式（７）中、Ｒ^７は水素原子又はメチル基であり、Ａ^７は単結合又は−ＣＯＯ−＊３（「＊３」はＢ^７に結合する結合手を示す。）であり、Ｂ^７は炭素数２〜１０のアルキレン基、炭素数６〜３０のアリーレン基又は炭素数４〜１０の２価の脂環式基である。）

(In formula (7), R ⁷ is a hydrogen atom or a methyl group, A ⁷ is a single bond or —COO— * 3 (“* 3” represents a bond bonded to B ⁷ ), and B ⁷ is an alkylene group having 2 to 10 carbon atoms, an arylene group having 6 to 30 carbon atoms, or a divalent alicyclic group having 4 to 10 carbon atoms.

In the above formula (7), the alkylene group having 2 to 10 carbon atoms ^{B 7,} an ethylene group, a 1,4-butylene group or the like;
Examples of the arylene group having 6 to 30 carbon atoms include a phenylene group;
Examples of the divalent alicyclic group having 4 to 10 carbon atoms include a cyclohexane-1,4-diyl group.

  As the repeating unit (a7), for example, each monomer such as isopropenyl phenol, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 4-hydroxybutyl acrylate, 1,4-cyclohexanedimethanol monoacrylate, and the like can be used. A repeating unit can be mentioned, Among these, the repeating unit obtained by 2-hydroxyethyl methacrylate is preferable.

  Polymer [A] may have a repeating unit (a7) individually by 1 type, and may have it in combination of 2 or more type. In the case where the polymer [A] has the repeating unit (a7), the liquid crystal aligning agent contains at least one polymer selected from the group consisting of polyamic acid and its imidized polymer. The compatibility of the polymer [A] with the polymer can be improved. Further, the content ratio of the repeating unit (a7) in the polymer [A] for enhancing the effect (or the copolymerization ratio of the monomer giving the repeating unit (a7)) is the total weight of the polymer [A]. (Or the total weight of monomers used in the synthesis of the polymer [A]) is preferably 50% by weight or less, more preferably 1% by weight or more and 40% by weight or less, and still more preferably 1% by weight or more and 30% by weight or less.

For the polymer [A], the weight average molecular weight in terms of polystyrene (hereinafter referred to as “Mw”) measured using gel permeation chromatography (GPC) is preferably 2 × 10 ³ or more and 1 × 10 ⁶ or less. Preferably it is 5 × 10 ³ or more and 5 × 10 ⁵ or less, and particularly preferably 1 × 10 ⁴ or more and 4 × 10 ⁵ or less. By setting Mw to 2 × 10 ³ or more, elution of low molecular components is suppressed and deterioration of panel characteristics is suppressed (elution of low molecular components causes a decrease in voltage holding ratio and panel burn-in). On the other hand, by setting it to 1 × 10 ⁶ or less, the solution viscosity of the obtained liquid crystal aligning agent can be made moderate, and the coating property can be improved. The molecular weight distribution (hereinafter referred to as “Mw / Mn”. Mn is the number average molecular weight in terms of polystyrene measured using GPC) is preferably 20.0 or less, more preferably 15.0 or less. Especially preferably, it is 10.0 or less. By reducing Mw / Mn, it becomes easy to obtain a liquid crystal aligning agent that has excellent coating properties and does not cause the problem of deterioration in panel characteristics due to elution of the low molecular components described above.

[Production Method of Polymer [A]]
The method for producing the polymer [A] is not particularly limited. For example, one or more corresponding radical polymerizable monomers are present in a suitable polymerization solvent in the presence of an appropriately selected initiator or chain transfer agent. Can be produced by radical polymerization. The use ratio (copolymerization ratio) of the monomer that gives the repeating units (a1) to (a7) during the polymerization can be appropriately set depending on the composition of the desired polymer [A].

Examples of the polymerization solvent include alcohols such as methanol, ethanol, benzyl alcohol, 2-phenylethyl alcohol, and 3-phenyl-1-propanol;
Ethers such as tetrahydrofuran and di-n-amyl ether; glycol ethers such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether;
Ethylene glycol alkyl ether acetates such as methyl cellosolve acetate, ethyl cellosolve acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monoethyl ether acetate;
Diethylene glycol alkyl ethers such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol ethyl methyl ether;
Propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether;
Propylene glycol alkyl ether acetates such as propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol propyl ether acetate, propylene glycol butyl ether acetate;
Propylene glycol alkyl ether propionates such as propylene glycol methyl ether propionate, propylene glycol ethyl ether propionate, propylene glycol propyl ether propionate, propylene glycol butyl ether propionate;
Aromatic hydrocarbons such as toluene and xylene;
Ketones such as methyl ethyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone, diisobutyl ketone;
Methyl acetate, ethyl acetate, propyl acetate, butyl acetate, ethyl 2-hydroxypropionate, methyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, methyl hydroxyacetate, hydroxyethyl acetate, hydroxy Butyl acetate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, methyl 3-hydroxypropionate, ethyl 3-hydroxypropionate, propyl 3-hydroxypropionate, butyl 3-hydroxypropionate, 2-hydroxy-3-methylbutane Methyl acetate, methyl methoxyacetate, ethyl methoxyacetate, propyl methoxyacetate, butyl methoxyacetate, methyl ethoxy acetate, ethyl ethoxy acetate, propyl ethoxy acetate, butyl ethoxy acetate, methyl propoxyacetate, propoxy Ethyl acetate, propyl propoxyacetate, butyl propoxyacetate, methyl butoxyacetate, ethyl butoxyacetate, propyl butoxyacetate, butyl butoxyacetate, methyl 2-methoxypropionate, ethyl 2-methoxypropionate, propyl 2-methoxypropionate, 2- Butyl methoxypropionate, methyl 2-ethoxypropionate, ethyl 2-ethoxypropionate, propyl 2-ethoxypropionate, butyl 2-ethoxypropionate, methyl 2-butoxypropionate, ethyl 2-butoxypropionate, 2-butoxy Propyl propionate, butyl 2-butoxypropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, butyl 3-methoxypropionate, 3- Methyl toxipropionate, ethyl 3-ethoxypropionate, propyl 3-ethoxypropionate, butyl 3-ethoxypropionate, methyl 3-propoxypropionate, ethyl 3-propoxypropionate, propyl 3-propoxypropionate, 3-propoxy Esters such as butyl propionate, methyl 3-butoxypropionate, ethyl 3-butoxypropionate, propyl 3-butoxypropionate, butyl 3-butoxypropionate;
Etc.

  Of these, ethylene glycol alkyl ether acetate, diethylene glycol alkyl ether, propylene glycol monoalkyl ether, and propylene glycol alkyl ether acetate are preferable. Particularly, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol. Methyl ether acetate or methyl 3-methoxypropionate is preferred.

  As said polymerization initiator, what is generally known as a radical polymerization initiator can be used. For example, 2,2′-azobisisobutyronitrile, 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobis- (4-methoxy-2,4-dimethylvaleronitrile) Azo compounds such as benzoyl peroxide, lauroyl peroxide, t-butyl peroxypivalate, organic peroxides such as 1,1′-bis- (t-butylperoxy) cyclohexane, and hydrogen peroxide. When a peroxide is used as the radical polymerization initiator, the peroxide may be used together with a reducing agent to form a redox initiator.

  In the synthesis of the polymer [A], a molecular weight modifier can be used to adjust the molecular weight of the polymer [A]. Specific examples thereof include halogenated hydrocarbons such as chloroform and carbon tetrabromide; mercaptans such as n-hexyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, tert-dodecyl mercaptan, thioglycolic acid; dimethylxanthogen sulfide, Xanthogens such as diisopropylxanthogen disulfide; terpinolene, α-methylstyrene dimer and the like.

  In the synthesis of the polymer [A], the polymerization conditions (solvent species, charge ratio of solvent and monomer, polymerization temperature, initiator species and their addition amount, types of molecular weight regulator and their addition amount, etc.) are appropriately selected. It is preferable to control to the above molecular weight range by adjusting. Appropriate polymerization conditions for realizing the above molecular weight range can be easily estimated by a person skilled in the art by performing a few preliminary experiments.

  As described above, a polymer solution containing the polymer [A] is obtained. This polymer solution may be used for the preparation of the liquid crystal aligning agent as it is, and may be used for the preparation of the liquid crystal aligning agent after the polymer [A] contained in the polymer solution is isolated or isolated. You may use for preparation of a liquid crystal aligning agent, after refine | purifying polymer [A]. The polymer [A] is isolated by a method of drying the precipitate obtained by pouring the polymer solution into a large amount of a poor solvent, or a method of distilling the polymer solution under reduced pressure using an evaporator. be able to. In addition, the polymer [A] can be obtained by dissolving the isolated polymer [A] in an organic solvent again and then precipitating with a poor solvent, or by performing the step of evaporating under reduced pressure with an evaporator once or several times. Can be purified.

  The content of the polymer [A] in the liquid crystal aligning agent is preferably 3 parts by weight or more and 20 parts by weight or less with respect to 100 parts by weight of the polymer [B] described later. As a result, it is possible to suitably realize an improvement in durability so that the alignment performance of the liquid crystal is maintained even for long-term use. More preferably, it is 3 parts by weight or more and 15 parts by weight or less, and particularly preferably 3 parts by weight or more and 10 parts by weight or less.

<Polymer [B]>
The liquid crystal aligning agent of this invention is at least 1 type selected from the group which consists of polyamic acid obtained by making tetracarboxylic dianhydride and diamine react in addition to the said polymer [A], and its imidized polymer. It may contain polymer [B] which is.

[Tetracarboxylic dianhydride]
Examples of tetracarboxylic dianhydrides used to synthesize the polyamic acid include aliphatic tetracarboxylic dianhydrides, alicyclic tetracarboxylic dianhydrides, aromatic tetracarboxylic dianhydrides, and the like. be able to.

Specifically, each of these tetracarboxylic dianhydrides includes, for example, butanetetracarboxylic dianhydride as an aliphatic tetracarboxylic dianhydride;
As the alicyclic tetracarboxylic dianhydride, for example, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-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-1,2-dicarboxylic anhydride, 3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-dianhydride, 2 , 4,6,8-tetracarboxybicyclo [3.3.0] octane-2,4,6,8-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^2,6 ] Undecane-3,5,8,10-tetraone and the like;
As aromatic tetracarboxylic dianhydride, for example, pyromellitic dianhydride;
In addition to the above,
Tetracarboxylic dianhydrides described in JP 2010-97188 A can be used.

  Among these, the tetracarboxylic dianhydride used for synthesizing the polyamic acid preferably includes an alicyclic tetracarboxylic dianhydride, and more specifically, 2, 3, 5 -It preferably contains tricarboxycyclopentylacetic acid dianhydride or 1,2,3,4-cyclobutanetetracarboxylic dianhydride, and particularly contains 2,3,5-tricarboxycyclopentylacetic acid dianhydride. preferable.

  As the tetracarboxylic dianhydride used to synthesize the polyamic acid, 2,3,5-tricarboxycyclopentylacetic acid dianhydride or 1,2,3,4-cyclobutanetetracarboxylic dianhydride, It is preferable to contain 10 mol% or more, more preferably 20 mol% or more, and more preferably 2,3,5-tricarboxycyclopentylacetic acid dianhydride or 1,2,2. Most preferably, it consists only of 3,4-cyclobutanetetracarboxylic dianhydride.

[Diamine]
Examples of diamines used to synthesize the polyamic acid include aliphatic diamines, alicyclic diamines, aromatic diamines, diaminoorganosiloxanes, and the like.

Specific examples thereof include aliphatic diamines such as 1,1-metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine and the like;
Examples of alicyclic diamines include 1,4-diaminocyclohexane, 4,4′-methylenebis (cyclohexylamine), 1,3-bis (aminomethyl) cyclohexane and the like;
As aromatic diamines, for example, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfide, 1,5-diaminonaphthalene, 2,2'- Dimethyl-4,4′-diaminobiphenyl, 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl, 2,7-diaminofluorene, 4,4′-diaminodiphenyl ether, 4,4′- Diamino-2,2′-dimethylbiphenyl, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 9,9-bis (4-aminophenyl) fluorene, 2,2-bis [4- ( 4-Aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane 4,4 ′-(p-phenylenediisopropylidene) bisaniline, 4,4 ′-(m-phenylenediisopropylidene) bisaniline, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis ( 4-aminophenoxy) biphenyl, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminoacridine, 3,6-diaminocarbazole, N-methyl-3,6- Diaminocarbazole, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N, N′-bis (4-aminophenyl) -benzidine, N, N′-bis (4-amino) Phenyl) -N, N′-dimethylbenzidine, 1,4-bis- (4-aminophenyl) -piperazine, 3,5-diaminobenzoic acid, Decanoxy-2,4-diaminobenzene, tetradecanoxy-2,4-diaminobenzene, pentadecanoxy-2,4-diaminobenzene, hexadecanoxy-2,4-diaminobenzene, octadecanoxy-2,4-diaminobenzene, dodecanoxy-2,5 -Diaminobenzene, tetradecanoxy-2,5-diaminobenzene, pentadecanoxy-2,5-diaminobenzene, hexadecanoxy-2,5-diaminobenzene, octadecanoxy-2,5-diaminobenzene, cholestanyloxy-3,5-diaminobenzene Cholestenyloxy-3,5-diaminobenzene, cholestanyloxy-2,4-diaminobenzene, cholestenyloxy-2,4-diaminobenzene, cholestanyl 3,5-diaminobenzoate, 3,5-diamy Cholestenyl nobenzoate, lanostannyl 3,5-diaminobenzoate, 3,6-bis (4-aminobenzoyloxy) cholestane, 3,6-bis (4-aminophenoxy) cholestane, 4- (4′-trifluoromethoxy) Benzyloxy) cyclohexyl-3,5-diaminobenzoate, 4- (4′-trifluoromethylbenzoyloxy) cyclohexyl-3,5-diaminobenzoate, 1,1-bis (4-((aminophenyl) methyl) Phenyl) -4-butylcyclohexane, 1,1-bis (4-((aminophenyl) methyl) phenyl) -4-heptylcyclohexane, 1,1-bis (4-((aminophenoxy) methyl) phenyl) -4 -Heptylcyclohexane, 1,1-bis (4-((aminophenyl) methyl) phenyl) -4 (4-heptylcyclohexyl) cyclohexane, 2,4-diamino-N, N-diallylaniline, 4-aminobenzylamine, 3-aminobenzylamine, 1- (2,4-diaminophenyl) piperazine-4-carboxylic acid, 4 -(Morpholin-4-yl) benzene-1,3-diamine, 1,3-bis (N- (4-aminophenyl) piperidinyl) propane, α-amino-ω-aminophenylalkylene and the following formula (D1)

（式（Ｄ１）中、Ｘ^Ｉ及びＸ^ＩＩは、それぞれ、単結合、−Ｏ−、−ＣＯＯ−又は−ＯＣＯ−であり、Ｒ^ｄ１は、メチレン基又は炭素数２若しくは３のアルキレン基であり、ａは０又は１であり、ｂは０〜２の整数であり、ｃは１〜２０の整数であり、ｄは０又は１である。但し、ａ及びｂが同時に０になることはない。）
で表される化合物などを；
ジアミノオルガノシロキサンとして、例えば１，３−ビス（３−アミノプロピル）−テトラメチルジシロキサンなどを、それぞれ挙げることができるほか、特開２０１０−９７１８８号に記載のジアミンを用いることができる。

(In Formula (D1), X ^I and X ^II are each a single bond, —O—, —COO—, or —OCO—, and R ^d1 is a methylene group or an alkylene group having 2 or 3 carbon atoms. , A is 0 or 1, b is an integer of 0 to 2, c is an integer of 1 to 20, and d is 0 or 1. However, a and b are not 0 at the same time. .)
A compound represented by:
Examples of the diaminoorganosiloxane include 1,3-bis (3-aminopropyl) -tetramethyldisiloxane, and the like, and diamines described in JP 2010-97188 A can be used.

^-X I in the formula ^{(D1) - (R d1 -X} II) d - Examples of the divalent group represented by a methylene group, an alkylene group having a carbon number of 2 or 3, * 4-O -, * 4 It is preferably —COO— or * 4-O—CH ₂ CH ₂ —O— (however, the bond marked with “* 4” is bonded to the diaminophenyl group). Specific examples of —C _c H _{2c + 1} group include, for example, methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n -Nonyl group, n-decyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, n-nonadecyl group, n -An eicosyl group etc. can be mentioned. The two amino groups in the diaminophenyl group are preferably in the 2,4-position or 3,5-position with respect to other groups.

  Specific examples of the compound represented by the formula (D1) include compounds represented by the following formulas (D1-1) to (D1-3).

  Among the diamines listed above, as diamines used for the synthesis of the polymer [B], p-phenylenediamine, 4,4′-diaminodiphenylmethane, 2,7-diaminofluorene, 4,4′-diaminodiphenyl ether, It preferably contains at least one selected from the group consisting of 4,4′-diamino-2,2′-dimethylbiphenyl and 1,3-bis (aminomethyl) cyclohexane.

  The liquid crystal aligning agent of the present invention expresses a desired pretilt angle by adjusting the composition of the polymer [A] and the content of the polymer [A] in the liquid crystal aligning agent to an appropriate range. However, when the liquid crystal aligning agent of the present invention is used for a TN type, STN type, OCB type or VA type liquid crystal display element, the diamine used for the synthesis of the polymer [B] contained in the liquid crystal aligning agent It is also possible to control the pretilt angle of the obtained liquid crystal alignment film by using a diamine having a pretilt angle developing site as

  Examples of the diamine having such a pretilt angle-expressing site include compounds represented by the following general formula (D2) or the following general formula (D3).

（式（Ｄ２）中、Ｒ^ｄ２及びＲ^ｄ３は、それぞれ、水素原子又はメチル基であり、Ｒ^ｄ４は直鎖状又は分岐状の炭素原子数１〜２０のアルキル基であり、Ｒ^ｄ５及びＲ^ｄ６は、それぞれ、２価の有機基である。）

(In formula (D2), R ^d2 and R ^d3 are each a hydrogen atom or a methyl group, R ^d4 is a linear or branched alkyl group having 1 to 20 carbon atoms, R ^d5 and R ^{d3 d6} is a divalent organic group.

（式（Ｄ３）中、Ｒ^ｄ７は、酸素原子、硫黄原子、−ＣＯ−、−ＣＯＯ−、−ＯＣＯ−、−ＮＨＣＯ−、−ＣＯＮＨ−又はメチレン基であり、Ｒ^ｄ８は、コレスタニル骨格若しくはコレステニル骨格を有する１価の基、トリフルオロメチルフェニル基若しくはトリフルオロメトキシフェニル基を有する１価の基又は炭素数１〜２２のアルキル基であり、Ｒ^ｄ９は炭素数１〜４のアルキル基であり、ｄは０〜３の整数である。）

(In the formula (D3), R ^d7 is an oxygen atom, a sulfur atom, —CO—, —COO—, —OCO—, —NHCO—, —CONH—, or a methylene group, and R ^d8 represents a cholestanyl skeleton or cholestenyl. A monovalent group having a skeleton, a monovalent group having a trifluoromethylphenyl group or a trifluoromethoxyphenyl group, or an alkyl group having 1 to 22 carbon atoms, and R ^d9 is an alkyl group having 1 to 4 carbon atoms. And d is an integer of 0 to 3.)

  Specific examples of the compound represented by the above formula (D2) include, for example, compounds represented by the following formulas (D2-1) and (D2-2).

上記式（Ｄ３）中、Ｒ^１８のコレスタニル骨格又はコレステニル骨格を有する１価の基としては、炭素数１７〜３０のものが好ましく、例えば３−コレスタニル基、３−コレステニル基等を挙げることができる。また、Ｒ^１９はメチル基であることが好ましく、ａ３は０又は１であることが好ましく、０であることがより好ましい。

In the formula (D3), the monovalent group having a cholestanyl skeleton or a cholestenyl skeleton of R ¹⁸ is preferably a group having 17 to 30 carbon atoms, and examples thereof include a 3-cholestanyl group and a 3-cholestenyl group. . R ¹⁹ is preferably a methyl group, a3 is preferably 0 or 1, and more preferably 0.

  Specific examples of the compound represented by the formula (D3) include compounds represented by the following formulas (D3-1) to (D3-5).

  The diamine compounds having the pretilt angle expression sites as described above are used singly or in combination of two or more.

  When the liquid crystal aligning agent of the present invention is used for a VA type liquid crystal display element, the liquid crystal aligning agent exhibits an excellent vertical alignment property of liquid crystal, and therefore is represented by the formula (D3) among the diamine compounds having the pretilt angle developing site. It is preferable to use at least one compound selected from the compounds represented by the formulas (D3-1) to (D3-5), and particularly the formula (D3- It is preferable to use at least one of the compound represented by 1) and the compound represented by the above formula (D3-2).

  The ratio of the diamine having a pretilt angle-expressing site is preferably 8 mol% or more and 60 mol% or less, more preferably 9 mol% or more and 50 mol% or less, and particularly preferably 10 mol% with respect to the total diamine. % Or more and 40 mol% or less. In this case, a diamine having a pretilt angle expression site and another diamine may be used in combination, and the use ratio of the other diamine in such a case is preferably 1 mol% or more and 90 mol% or less with respect to the total diamine. More preferably, it is 10 mol% or more and 90 mol% or less.

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

Examples of the molecular weight regulator include acid monoanhydrides, monoamine compounds, monoisocyanate compounds, and the like. Specific examples of these acid monoanhydrides include maleic anhydride, phthalic anhydride, itaconic anhydride, n-decylsuccinic anhydride, n-dodecylsuccinic anhydride, n-tetradecylsuccinic acid. Nic acid anhydride, n-hexadecyl succinic acid anhydride, etc .;
Examples of monoamine compounds include aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, and n-octylamine;
Examples of the monoisocyanate compound include phenyl isocyanate and naphthyl isocyanate.

  The use ratio of the molecular weight regulator is preferably 20 parts by weight or less, and more preferably 10 parts by weight or less with respect to 100 parts by weight of the total of the tetracarboxylic dianhydride and diamine used.

[Synthesis of polyamic acid]
The ratio of the tetracarboxylic dianhydride and the diamine used in the polyamic acid synthesis reaction is 0.2 to 2 for the tetracarboxylic dianhydride acid anhydride group to 1 equivalent of the amino group of the diamine. The ratio which becomes an equivalent is preferable, More preferably, it is the ratio which becomes 0.3-1.2 equivalent.

  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 an aprotic polar solvent, phenol and derivatives thereof, alcohol, ketone, ester, ether, halogenated hydrocarbon, and hydrocarbon.

Specific examples of these organic solvents include, for example, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea as the aprotic polar solvent. Hexamethylphosphotriamide, etc .;
Examples of the phenol derivative include m-cresol, xylenol, halogenated phenol and the like;
Examples of the alcohol include methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, and ethylene glycol monomethyl ether;
Examples of the ketone include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone;
Examples of the ester include ethyl lactate, butyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, diethyl oxalate, and diethyl malonate;
Examples of the ether include diethyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol-n-butyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate. Diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, tetrahydrofuran 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, isoamylpropionate, isoamylisobutyrate, and diisopentyl ether.

  Among these organic solvents, one or more selected from the group consisting of an aprotic polar solvent and phenol and derivatives thereof (first group organic solvent), or one selected from the first group of organic solvents It is preferable to use a mixture of the above and one or more selected from the group consisting of alcohols, ketones, esters, ethers, halogenated hydrocarbons and hydrocarbons (second group organic solvent). In the latter case, the use ratio of the second group of organic solvents is preferably 50% by weight or less, more preferably 40% by weight or less, based on the total of the first group of organic solvents and the second group of organic solvents. Furthermore, it is preferable that it is 30 weight% 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 a known method.

[Synthesis of polyimide]
Polyimide can be obtained by dehydrating and ring-closing the polyamic acid synthesized as described above to imidize.

  The polyimide in the present invention may be a completely imidized product obtained by dehydrating and cyclizing all of the amic acid structure that the polyamic acid that is a precursor thereof has, or by dehydrating and cyclizing only a part of the amic acid structure, A partially imidized product in which a structure and an imide ring structure coexist may be used. The polyimide in the present invention preferably has an imidation ratio of 30% or more, more preferably 50% or more and 99% or less, and more preferably 65% or more and 99% or less. 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 if necessary. . Of these, the latter method is preferred.

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

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

[Solution viscosity of polymer [B]]
The polymer [B] obtained as described above preferably has a solution viscosity of 20 to 800 mPa · s, and is 30 to 500 mPa · s, when this is a 10% by weight solution. More preferably, it has a solution viscosity.

  The solution viscosity (mPa · s) of the polymer [B] is a concentration of 10% by weight prepared using a good solvent (for example, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.) of the polymer [B]. It is a value measured at 25 ° C. using an E-type viscometer for the polymer solution.

<Other additives>
The liquid crystal alignment film of the present invention contains the polymer [A] as an essential component and more preferably contains the polymer [B], but may contain other components as necessary. Good. Examples of such other components include other polymers, compounds having at least one epoxy group in the molecule (hereinafter referred to as “epoxy compound”), functional silane compounds, and the like.

[Epoxy compound]
Examples of the epoxy 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, and 1,6-hexane. Diol 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'-diaminodiphenylme Emissions, N, N-diglycidyl - benzylamine, N, N-diglycidyl - aminomethyl cyclohexane, N, N-diglycidyl - may be mentioned as being preferred and cyclohexylamine.

  The blending ratio of these epoxy compounds 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 amount of the polymer.

[Functional silane compounds]
Examples of the functional silane compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl)- 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyl Trimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4 7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9- Triethoxysilyl-3,6-diazanonyl acetate, methyl 9-trimethoxysilyl-3,6-diazananoate, methyl 9-triethoxysilyl-3,6-diazananoate, N-benzyl-3-aminopropyltri Methoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, glycidoxymethyltrimethoxysilane, glycidoxy Methyltriethoxysilane, 2-glycidoxyethyltrimeth Shishiran, 2-glycidoxyethyl triethoxysilane, 3-glycidoxypropyltrimethoxysilane, can be mentioned 3-glycidoxypropyl triethoxysilane.

  The blending ratio of these functional silane compounds is preferably 2 parts by weight or less, more preferably 0.02 to 0.2 parts by weight with respect to 100 parts by weight of the total amount of the polymer.

<Liquid crystal aligning agent>
The liquid crystal aligning agent of the present invention comprises the polymer [A] and the polymer [B], and other additives optionally blended as required, preferably dissolved and contained in an organic solvent. Is done.

  Examples of the organic solvent used in the liquid crystal aligning agent of the present invention include N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N, N-dimethylformamide, N, N-dimethylacetamide, 4-hydroxy- 4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether , Ethylene glycol-i-propyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl Ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, diisopentyl ether, ethylene carbonate, propylene carbonate, etc. Can be mentioned. These can be used alone or in admixture of two or more.

  The solid content concentration in the liquid crystal aligning agent of the present invention (the ratio of the total weight of components other than the solvent of the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) is appropriately selected in consideration of viscosity, volatility, and the like. The range is preferably 1 to 10% by weight. That is, the liquid crystal aligning agent of the present invention is applied to the substrate surface as described later, and preferably, when heated, a liquid crystal alignment film or a liquid crystal alignment film is formed. When the concentration is less than 1% by weight, the film thickness of the coating film is too small to obtain a good liquid crystal alignment film, while when the solid content concentration exceeds 10% by weight, The film thickness becomes too large to obtain a good liquid crystal alignment film, and the viscosity of the liquid crystal aligning agent increases, resulting in poor coating properties.

  The particularly preferable range of the solid content concentration varies depending on the method used when the liquid crystal aligning agent is applied to the substrate. For example, when the spinner method is used, the solid content concentration is particularly preferably in the range of 1.5 to 4.5% by weight. In the case of the printing method, it is particularly preferable that the solid content concentration is in the range of 3 to 9% by weight, and thereby the solution viscosity is in the range of 12 to 50 mPa · s. In the case of the inkjet method, it is particularly preferable that the solid content concentration is in the range of 1 to 5% by weight, and thereby the solution viscosity is in the range of 3 to 15 mPa · s.

  The temperature at the time of preparing the liquid crystal aligning agent of this invention becomes like this. Preferably it is 10-50 degreeC, More preferably, it is 20-30 degreeC.

<Liquid crystal alignment film and liquid crystal display element>
The liquid crystal alignment film of the present invention is formed by the above liquid crystal aligning agent. Moreover, the liquid crystal display element of this invention comprises this liquid crystal aligning film. The operation mode in the liquid crystal display element may be applied to a horizontal alignment type such as an IPS type, a TN type, and an STN type, or may be applied to a vertical alignment type such as a VA 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 also demonstrated in the description. The liquid crystal display element of the present invention can be produced, for example, by the following steps (P1) to (P3).

[Step (P1): 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.

  (P1-1) 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, and then each coated surface is heated (preferably pre-heated (pre-baked) and fired (post-baked). ) To form a coating film. Here, since the liquid crystal aligning agent of this invention is excellent in printability, it is preferable from the viewpoint that the offset printing method is employ | adopted as an application | coating method to exhibit the outstanding effect of this invention to the maximum.

  Examples of the substrate include glass substrates such as float glass and soda glass, polyethylene naphthalate, triacetylcellulose (TAC), polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polyamide, polyimide, polymethyl methacrylate, polycarbonate, poly ( A transparent substrate made of plastic such as alicyclic 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. In order to obtain a patterned transparent conductive film which can be used, for example, a method of forming a pattern by photo-etching after forming a transparent conductive film without a pattern, a mask having a desired pattern when forming the transparent conductive film The method using can be used. 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.

  The coated surface after application of the liquid crystal aligning agent is then pre-heated (pre-baked) and further baked (post-baked) to form a coating film. 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. 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.

  (P1-2) On the other hand, in the case of manufacturing an IPS liquid crystal display element, a conductive film forming surface of a substrate provided with a transparent conductive film patterned in a comb shape and a counter substrate provided with no conductive film are provided. The liquid crystal aligning agent of this invention is apply | coated to one surface, respectively, Then, a coating film is formed by heating each application surface. Regarding the material used for the substrate and the transparent conductive film, the coating method, the heating conditions after coating, the patterning method for the transparent conductive film, the pretreatment of the substrate, and the preferred film thickness of the coating film to be formed (P1-1). ).

  In both cases (P1-1) and (P1-2), after applying the liquid crystal aligning agent on the substrate, the organic solvent is removed to form a coating film that becomes an alignment film. In this case, it is good also as a more imidized coating film by advancing the dehydration ring-closing reaction by further heating after forming the coating film.

[Step (P2): rubbing treatment]
When manufacturing a TN type, STN type, or IPS type liquid crystal display element, the coating film formed as described above is fixed in a certain direction with a roll wound with a cloth made of fibers such as nylon, rayon, and cotton. Apply rubbing 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.

  Furthermore, with respect to the liquid crystal alignment film, a treatment for changing the pretilt angle of a part of the liquid crystal alignment film by irradiating a part of the liquid crystal alignment film with ultraviolet rays, or a resist film on a part of the liquid crystal alignment film surface A liquid crystal display obtained by forming a liquid crystal and performing a rubbing process in a direction different from the previous rubbing process and then removing the resist film so that the liquid crystal alignment film has different liquid crystal alignment capabilities in each region. It is possible to improve the visibility characteristics of the element.

  In addition, when manufacturing a VA type liquid crystal display element, although the coating film formed at the said process (1) can be used as a liquid crystal aligning film as it is, you may give said rubbing process.

[Step (P3): Construction of liquid crystal cell]
In order to dispose the liquid crystal between the substrates, for example, there are the following two methods.

  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 face each other, and the peripheral portions of the two substrates are bonded together using a sealant, and the substrate surface and the seal are bonded. After injecting and filling the liquid crystal into the cell gap partitioned by the agent, the liquid crystal cell can be manufactured by 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. After applying and dropping the liquid crystal on the liquid crystal alignment film surface, the other substrate is bonded so that the liquid crystal alignment film faces, and then the entire surface of the substrate is irradiated with ultraviolet light to cure the sealing agent, A liquid crystal cell can be manufactured.

  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, so that the flow alignment during liquid crystal injection is achieved. 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. Liquid crystals, biphenylcyclohexane liquid crystals, pyrimidine liquid crystals, dioxane liquid crystals, bicyclooctane liquid crystals, cubane liquid crystals, and the like can be used. In addition, cholesteric liquid crystals such as cholestyl chloride, cholesteryl nonate, and cholesteryl carbonate; chiral products such as those sold under the trade names “C-15” and “CB-15” (manufactured by Merck) Agent: Ferroelectric liquid crystal such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate may be added and used.

  The liquid crystal display element of the present invention can be obtained by attaching a polarizing plate to the outer surface of the liquid crystal cell. Examples of the polarizing plate include a polarizing plate formed by sandwiching a polarizing film called “H film” in which iodine is absorbed while stretching and orientation of polyvinyl alcohol are sandwiched between cellulose acetate protective films, or a polarizing film made of the H film itself. .

  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, various monitors. It can be used for a display device such as a liquid crystal television.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited by these examples. In each of the following synthesis examples, the necessary amount in the following polymerization examples was ensured by repeating the following scale as necessary.

<Synthesis of cholestanyl methacrylate>
[Synthesis Example 1]
After dissolving 800 g of β-cholestanol in 8,000 mL of dehydrated tetrahydrofuran (THF) and adding 270 g of triethylamine, 360 g of methacryloyl chloride was gradually added dropwise and stirred at room temperature for 3 hours to carry out the reaction. After completion of the reaction, triethylamine hydrochloride was removed by filtration, THF was removed by distillation under reduced pressure, and then 4,000 mL of chloroform was added. The resulting solution was washed with water and the organic layer was dried over magnesium sulfate, and then chloroform was removed by distillation under reduced pressure. Thereafter, recrystallization with ethanol was performed to obtain 540 g of cholestanyl methacrylate as a white solid (yield: 57.4%).

<Synthesis of Polymer [A]>
Commercially available compounds were used for the compounds other than the above-mentioned cholestanyl methacrylate. For example, 2,2,6,6-tetramethyl-4-piperidyl methacrylate and monomers 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate are monomers that give the repeating unit (a1). Commercial products “FA-712HM” and “FA-711MM” manufactured by Hitachi Chemical Co., Ltd. were used as they were, respectively.

  The weight average molecular weight (Mw) and the number average molecular weight (Mn) are GPC columns (2 G2000HXL, 1 G3000HXL, 1 G4000HXL) manufactured by Tosoh Corporation, and the flow rate is 1.0 ml / min. Measurement was performed by gel permeation chromatography (GPC) using monodisperse polystyrene as a standard under the analysis conditions of tetrahydrofuran and a column temperature of 40 ° C.

[Synthesis Example 2: Synthesis of Polymer [A-1]]
In a four-necked flask equipped with a stirrer, a three-way cock and a thermometer, 5 g (0.0222 mol) of 2,2,6,6-tetramethyl-4-piperidyl methacrylate was used as a monomer. The obtained cholestanyl methacrylate 30.0 g (0.0657 mol), glycidyl methacrylate 25.0 g (0.176 mol), methacrylic acid 10.0 g (0.116 mol), N-cyclohexylmaleimide 7.50 g (0.0418) Mol), 7.50 g (0.0720 mol) of styrene, and 15.0 g (0.115 mol) of 2-hydroxyethyl methacrylate, 200 g of diethylene glycol ethyl methyl ether as a solvent, and 2,2 as a polymerization initiator '-Azobis (2,4-dimethylvaleronitrile) 8.00 g and molecular weight modifier As a result, 4.00 g of α-methylstyrene dimer was added. This was bubbled with a nitrogen stream for about 10 minutes to perform nitrogen substitution in the system, and then reacted at 70 ° C. for 5 hours in a nitrogen atmosphere, thereby containing 33.2% by weight of the polymer [A-1]. A solution was obtained. When the molecular weight measurement of the polymer [A-1] was performed, it was Mw = 10,000 and Mw / Mn = 2.4, and the peak resulting from a residual monomer was not recognized.

[Synthesis Examples 3 to 10, Comparative Synthesis Examples 1 to 3]
For Synthesis Examples 3 to 10 and Comparative Synthesis Examples 1 and 3, the polymer [A-2] was prepared in the same manner as Synthesis Example 1 except that the types and composition ratios of the monomers used were as shown in Table 1 below. (Containing 33.1% by weight), polymer [A-3] (containing 33.2% by weight), polymer [A-4] (containing 33.1% by weight), polymer [A-5] (33 0.1 wt%), Polymer [A-6] (containing 33.2 wt%), Polymer [A-7] (containing 33.2 wt%), Polymer [A-8] (33.3 Polymer [A-9] (containing 33.0% by weight), polymer [R-1] (containing 33.1% by weight), polymer [R-3] (33.3% by weight). Solution) were prepared.

  In Comparative Synthesis Example 2, the types and composition ratios of the monomers used are as shown in Table 1 below, and 2,2′-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator is changed to 8. In the same manner as in Synthesis Example 1, except that 4.50 g is added instead of 00 g, and 2.00 g of α-methylstyrene dimer is added as a molecular weight modifier instead of 4.00 g, the polymer [R- 2] was prepared to prepare a polymer solution containing 33.0% by weight.

In Table 1, the abbreviations of the respective compounds are as follows.
[Repeating unit (a1)]
a1-1: 2,2,6,6-tetramethyl-4-piperidyl methacrylate a1-2: 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate a1-3: 2- (methacryloyloxy) ) -Ethyl-1,2,2,6,6-pentamethylpiperidine-4-carboxylate a1-4: 2,2,6,6-tetramethyl-1-octyloxy-4-piperidyl a1-5 methacrylate : Methacrylate 2,2,6,6-tetramethyl-1-oxo-4-piperidyl a1-6: Methacrylate 2,2,6,6-tetramethyl-1-benzyl-4-piperidyl a1-7: 2 -Propenyloxy-1,2,2,6,6-pentamethyl-4-piperinyl [repeating unit (a2)]
a2-1: Cholestanyl methacrylate a2-2: 4- (4′-pentylbicyclohexyl-4-yl) phenyl methacrylate [repeating unit (a3)]
a3-1: Glycidyl methacrylate [Repeating unit (a4)]
a4-1: Methacrylic acid [Repeating unit (a5)]
a5-1: N-cyclohexylmaleimide [Repeating unit (a6)]
a6-1: Styrene [Repeating unit (a7)]
a7-1: 2-hydroxyethyl methacrylate

<Synthesis of Polymer [B]>
In the following polymerization examples, the solution viscosity of each polymer solution and the imidization ratio of polyimide were measured by the following methods.

[Solution viscosity of polymer solution]
The solution viscosity (mPa · s) of the polymer solution was measured at 25 ° C. using an E-type rotational viscometer for a solution prepared to a polymer concentration of 10% by weight using a predetermined solvent.

[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.

Imidization rate (%) = (1-A ¹ / A ² × α) × 100
(A ¹ is the peak area derived from the proton of the NH group appearing in the vicinity of 10 ppm of chemical shift, A ² is the peak area derived from the other protons, and α is the proton of the NH group in the polymer precursor (polyamic acid). It is the number ratio of other protons to one.)

[Synthesis Example 11: Synthesis of Polymer [B-1]]
112 g (0.50 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as tetracarboxylic dianhydride and 43 g (0.40 mol) of p-phenylenediamine as diamine and the above formula (D3-1) Was dissolved in 830 g of N-methyl-2-pyrrolidone (NMP) and reacted at 60 ° C. for 6 hours to obtain a polyamic acid solution. A small amount of the obtained polyamic acid solution was collected, and NMP was added to measure the viscosity as a solution having a polyamic acid concentration of 10% by weight. As a result, it was 60 mPa · s.

  Next, 1,900 g of NMP was added to the obtained polyamic acid solution, 40 g of pyridine and 51 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration cyclization reaction, the solvent in the system was replaced with new NMP (in this operation, pyridine and acetic anhydride used for the dehydration cyclization reaction were removed from the system. The same applies hereinafter), whereby the imidation rate was reduced. About 1,400 g of a solution containing 15% by weight of 50% imidized polymer [B-1] was obtained. A small amount of this solution was taken, NMP was added, and the solution viscosity measured as a solution having an imidized polymer concentration of 10% by weight was 47 mPa · s.

[Synthesis Example 12: Synthesis of Polymer [B-2]]
112 g (0.50 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride, and 43 g (0.40 mol) of p-phenylenediamine as diamine and the above formula (D3-2) 49 g (0.10 mol) represented by the formula was dissolved in 820 g of NMP and reacted at 60 ° C. for 6 hours to obtain a polyamic acid solution. A small amount of the obtained polyamic acid solution was collected, and NMP was added to measure the viscosity as a solution having a polyamic acid concentration of 10% by weight. As a result, it was 60 mPa · s.

  Next, 1,900 g of NMP was added to the obtained polyamic acid solution, 40 g of pyridine and 51 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration ring-closing reaction, the solvent in the system was replaced with new NMP to obtain about 1,300 g of a solution containing 15% by weight of imidized polymer [B-2] having an imidization ratio of about 50%. . A small amount of this solution was taken, NMP was added, and the solution viscosity measured as a solution having an imidized polymer concentration of 10% by weight was 47 mPa · s.

[Synthesis Example 13: Synthesis of Polymer [B-3]]
112 g (0.50 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride, and 53 g (0.35 mol) of 3,5-diaminobenzoic acid as diamine, the above formula (D3 -1) 52 g (0.10 mol) of the compound represented by the above formula (D3-2) and 25 g (0.050 mol) of the compound represented by the above formula (D3-2) are dissolved in 970 g of NMP and reacted at 60 ° C. for 6 hours. A polyamic acid solution was obtained. A small amount of the obtained polyamic acid solution was collected, and NMP was added to measure the viscosity as a solution having a polyamic acid concentration of 10% by weight. As a result, it was 60 mPa · s.

  Next, 1,200 g of NMP was added to the obtained polyamic acid solution, 40 g of pyridine and 51 g of acetic anhydride were added, and dehydration ring closure reaction was performed at 110 ° C. for 4 hours. After the dehydration cyclization reaction, the solvent in the system was replaced with new NMP to obtain about 1,600 g of a solution containing 15% by weight of imidized polymer [B-3] having an imidization ratio of about 50%. . A small amount of this solution was collected, and NMP was added thereto, and the solution viscosity measured as a solution having an imidized polymer concentration of 10% by weight was 50 mPa · s.

<Preparation of liquid crystal aligning agent>
[Example 1]
A solution containing the polymer [A-1] obtained in Synthesis Example 2 and a solution containing the imidized polymer [B-1] obtained in Synthesis Example 11 were combined with the polymer [A-1 ]: The imidized polymer [B-1] was mixed at a weight ratio of 1:99, NMP and butyl cellosolve were added thereto, and the solvent composition was NMP: butyl cellosolve: diethylene glycol ethyl methyl ether = 49.6: A solution of 50: 0.4 (weight ratio) and a solid content concentration of 3.5% by weight was obtained. After sufficiently stirring this solution, a liquid crystal aligning agent was prepared by filtering using a filter having a pore size of 0.2 μm.

[Examples 2 to 13, Comparative Examples 1 to 4]
Examples 2 to 13 are the same as Example 1 except that the types and weight ratios of the polymer [A] and the imidized polymer [B] and the types and weight ratios of the solvents are as shown in Table 2 below. And the liquid crystal aligning agent about Comparative Examples 1-4 was prepared.

[Comparative Example 5]
NMP and butyl cellosolve are added to the solution containing the imidized polymer [B-1] obtained in Synthesis Example 11 and diluted, and the solvent composition is NMP: butyl cellosolve = 50: 50 (weight ratio), solid content concentration 3 A 5 wt% solution. After sufficiently stirring this solution, a liquid crystal aligning agent was prepared by filtering using a filter having a pore size of 0.2 μm.

[Comparative Examples 6 and 7]
In the above Comparative Example 5, a liquid crystal aligning agent was prepared in the same manner as in Comparative Example 5 except that the polymer solution was a solution containing a polymer described in Table 2 below.

<Manufacture of liquid crystal cells>
Each of the prepared liquid crystal aligning agents of Examples 1 to 13 and Comparative Examples 1 to 7 is made of an ITO film using a liquid crystal alignment film printer (Nissha Printing Co., Ltd.). After coating on the surface and heating (pre-baking) on a hot plate at 80 ° C. for 1 minute to remove the solvent, heating (post-baking) on a hot plate at 200 ° C. for 10 minutes to obtain a coating film with an average film thickness of 600 mm Formed. The coating film is rubbed with a rubbing machine having a roll wrapped with a rayon cloth at a roll rotation speed of 500 rpm, a stage moving speed of 3 cm / sec, and a hair foot indentation length of 0.4 mm to give liquid crystal alignment ability. did. Thereafter, ultrasonic cleaning was performed in ultrapure water for 1 minute, followed by drying in a 100 ° C. clean oven for 10 minutes to obtain a substrate having a liquid crystal alignment film. This operation was repeated to obtain a pair (two) of substrates having a liquid crystal alignment film.

  Next, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm is applied to either one of the outer edges of the pair of substrates having the liquid crystal alignment film, and then superposed so that the liquid crystal alignment film surfaces face each other. And then the adhesive was cured. Next, after filling nematic liquid crystal (MLC-6221 manufactured by Merck & Co., Inc.) between a pair of substrates from the liquid crystal injection port, the liquid crystal injection port is sealed with an acrylic photo-curing adhesive to produce a liquid crystal cell. did.

<Evaluation of liquid crystal cell>
[Evaluation of vertical alignment]
With respect to the vertical alignment type liquid crystal display device manufactured as described above, the pretilt angle was measured with an anchoring strength measuring device “OMS-J3” manufactured by Chuo Seiki Co., Ltd. When this pretilt angle is 87 ° or more, the vertical alignment is “good”, and when it is less than 87 °, the vertical alignment is “bad”.

[Evaluation of voltage retention]
The liquid crystal display device manufactured as described above was applied with a voltage of 5 V at 60 ° C. with an application time of 60 microseconds and a span of 1,670 milliseconds, and then held for 1,670 milliseconds after release of the application. The rate was measured under an atmosphere of 60 ° C. As a voltage holding ratio measuring apparatus, VHR-1 manufactured by Toyo Corporation was used. If the value of the voltage holding ratio is 97.5% or more, the voltage holding ratio is “good”, and if it is less than 97.5%, it can be said “bad”.

[Durability test of liquid crystal display elements (presence of display defects)]
In a high temperature and high humidity environment (temperature of 70 ° C., relative humidity of 80%), the liquid crystal display element is driven with a rectangular wave of 5 V and 60 Hz, and the presence or absence of white spot-like display defects after 1,500 hours has passed with a microscope. Observed. As a result, the case where there was no white spot-like display defect was evaluated as durability “good”, and the case where there was a white spot-like display defect was evaluated as durability “bad”.

[Evaluation of seizure resistance (measurement of residual DC voltage, acceleration test)]
The liquid crystal display device manufactured as described above was applied with a DC voltage of 17 V in an atmosphere of 100 ° C. for 20 hours, then the application of the voltage was released, and the liquid crystal cell was left to stand in a room temperature environment for 15 minutes. The residual voltage (residual DC voltage) was determined by the flicker elimination method. It can be determined that the smaller the value of the residual DC voltage is, the longer the liquid crystal display element has excellent seizure resistance. A liquid crystal display element having a residual DC voltage value of 200 mV or less has “good” seizure resistance. When the residual DC voltage value is larger than 200 mV, it can be said that seizure resistance is “bad”.

  The evaluation results of Examples 1 to 13 and Comparative Examples 1 to 7 are shown in Table 2 below together with the respective compositions.

As shown in Table 2, all of Examples 1 to 13 had good vertical alignment properties, voltage holding properties, durability, and seizure resistance. On the other hand, all of Comparative Examples 1 to 7 having no repeating unit (a1) were poor in durability. In addition, about Comparative Examples 1-7, it has confirmed that the display defect does not exist before starting a durability test.
Further, Comparative Example 2 having not only the repeating unit (a1) but also the repeating unit (a2) as the repeating unit of the polymer [A] was not only durable but also poor in vertical alignment. Further, Comparative Example 3 having not only the repeating unit (a1) but also the repeating unit (a3) as the repeating unit of the polymer [A] was not only durable but also had poor voltage holding property. Moreover, all of Comparative Examples 5 to 7 which did not contain the polymer [A] as a polymer component had poor seizure resistance in addition to durability.

Claims (7)

Containing a polymer having a repeating unit derived from an ethylenically unsaturated monomer;
The repeating unit is
Cyclic amine structure in which two carbon atoms adjacent to the nitrogen atom are each have two substituents represented by the following formula (S)
The liquid crystal aligning agent characterized by having.

(In the formula, R ¹¹ represents a single bond or an optionally substituted hydrocarbon group, and X represents a single bond, an oxygen atom, a sulfur atom, —CO—, —CO—O— or —O—CO—. R ¹² is an optionally substituted hydrocarbon group, provided that when X is not a single bond, R ¹¹ and R ¹² may be bonded to each other to form a ring structure.   2. The polymer according to claim 1, further comprising at least one polymer selected from the group consisting of a polyamic acid obtained by reacting tetracarboxylic dianhydride and diamine and an imidized polymer thereof. Liquid crystal aligning agent. The liquid crystal aligning agent according to claim 1, wherein the repeating unit is represented by the following formula (1-1 ) .

(In Formula (1-1 ) , R is a hydrogen atom or a methyl group, A ¹ is a single bond or a divalent linking group, and R ¹¹ is a single bond or an optionally substituted hydrocarbon, respectively. Each of X is a single bond, an oxygen atom, a sulfur atom, -CO-, -CO-O- or -O-CO-, and each of R ¹² is an optionally substituted hydrocarbon. Provided that when X is not a single bond, R ¹¹ and R ¹² may be bonded to each other to form a ring structure, wherein B ¹ is a hydrogen atom, oxygen An atom, a halogen atom, a hydroxyl group or a monovalent organic group, and m is an integer of 0 to 4. ) The liquid crystal aligning agent according to claim 3, wherein the repeating unit is represented by the following formula (1-1-1 ) .

(In Formula (1-1-1 ) , R is a hydrogen atom or a methyl group, A ¹ is a single bond or a divalent linking group, and R ¹³ is an alkyl group having 1 to 5 carbon atoms, respectively. In formula (1-1-1), B ¹ is a hydrogen atom, an oxygen atom, a halogen atom, a hydroxyl group or a monovalent organic group. 5. The liquid crystal aligning agent according to claim 1, wherein the polymer having the repeating unit further has a repeating unit represented by the following formula (2).

(In Formula (2), R ² is a hydrogen atom or a methyl group, A ² is a single bond or a divalent linking group, and B ² is a monovalent organic group having 17 to 30 carbon atoms and having a steroid skeleton. , A monovalent organic group having a tocopherol structure, or a monovalent organic group represented by the following formula (B2).

(B ²¹ is a cyclohexylene group, or a substituted or unsubstituted phenylene group, B ²² is a hydrogen atom or an alkyl group having 1 to 30 carbon atoms, and k is an integer of 0 to 3. However, when B ²² is a hydrogen atom, k is 1 or more, and when k is 2 or 3, a plurality of B ²¹ each independently has the above definition, “*” is bonded to A ² Shows the bonding hand to perform.))   The liquid crystal aligning film formed with the liquid crystal aligning agent of any one of Claims 1 thru | or 5.   A liquid crystal display device comprising the liquid crystal alignment film according to claim 6.