JP5655583B2 - 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, relates to a liquid crystal alignment film and a liquid crystal display element.

  Liquid crystal displays are currently applied to many devices such as televisions, car navigation systems, and mobile phones, and are used in various environments as essential items for daily life. For example, car navigation systems are expected to be used in a high temperature environment in summer or used for a long time. Therefore, it is desired to develop a liquid crystal display that exhibits high-quality display characteristics in a high-temperature environment, and exhibits low afterimage characteristics with little image sticking when displayed for a long time. In addition, in order to obtain a liquid crystal display having these characteristics, development of a liquid crystal display element that can maintain a high voltage holding ratio even in a high temperature environment, has little charge accumulation (residual DC) with respect to a DC voltage, and easily releases accumulated charge. It has been demanded. In order to develop such a liquid crystal display element, the key is to improve the performance of the liquid crystal alignment film, which has a great influence on the voltage holding ratio and the residual DC characteristics. On the other hand, alignment films with good low afterimage characteristics often increase the ion density in the liquid crystal, making it difficult to produce alignment films with good low afterimage characteristics and high voltage holding ratio. It was.

  In order to solve such a problem, various liquid crystal aligning agents for forming a liquid crystal alignment film have been conventionally proposed (see, for example, Patent Document 1 and Patent Document 2). In Patent Document 1, a liquid crystal alignment comprising an imidized polymer obtained by reaction of a diamine having two primary amino groups and nitrogen atoms other than the primary amino group in the molecule with tetracarboxylic dianhydride. Agents have been proposed. Moreover, in patent document 2, the voltage in a high temperature environment is used using the liquid crystal aligning agent containing the polyamic acid etc. which are obtained by reaction of diamine represented by 4,4'- diamino diphenylamine, and tetracarboxylic dianhydride. It has been proposed to improve retention and low afterimage characteristics.

JP-A-10-104633 Japanese Patent No. 4052307

  In recent years, the demand for higher performance of liquid crystal displays and, moreover, higher performance of liquid crystal display elements has further increased, and the evaluation and selection of materials are performed under more severe conditions. For these reasons, there is a demand for a liquid crystal alignment film material that exhibits even better physical properties than conventional ones.

The present invention has been made in view of the above problems, with showing a high voltage holding ratio under the high temperature environment, the liquid crystal aligning agent to obtain a liquid crystal display element with excellent low residual image characteristic, using a Re co Biniso produced The main object is to provide a liquid crystal alignment film and a liquid crystal display element.

  As a result of intensive studies to solve the problems of the prior art as described above, the present inventors have incorporated a polyamic acid having a specific structure derived from pyridine and an imidized polymer thereof into a liquid crystal aligning agent, thereby The present inventors have found that the problem can be solved and have completed the present invention. Specifically, the following liquid crystal aligning agent, liquid crystal aligning film, liquid crystal display element, compound and polymer are provided by the present invention.

（式（１）中、Ｒ^１は、ハロゲン原子、炭素数１〜６のアルキル基、アルコキシ基又はフルオロアルキル基である。ｍは０〜３の整数であり、ｍが２又は３の場合、複数のＲ^１はそれぞれ独立して上記定義を有する。「＊」は結合手を示す。） According to the present invention, it contains at least one polymer selected from the group consisting of polyamic acid obtained by reacting tetracarboxylic dianhydride and diamine and an imidized polymer thereof, and the polymer is A liquid crystal aligning agent characterized by having a structure represented by the following formula (1) is provided.

(In Formula (1), R ¹ is a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group or a fluoroalkyl group. M is an integer of 0 to 3, and when m is 2 or 3, (Several R ^{1 s} independently have the above definition. “*” Represents a bond.)

  According to the liquid crystal aligning agent of this invention, the liquid crystal aligning film for obtaining the liquid crystal display element which shows a high voltage holding ratio in a high temperature environment and was excellent in the low afterimage characteristic can be produced. Moreover, by producing a liquid crystal display element using the liquid crystal alignment film of the present invention, the liquid crystal display element can maintain a high-quality display in a high-temperature environment, and also when a long-time display is performed. Burn-in can be made difficult to occur.

（式（２）中、Ａは、それぞれ独立に、単結合、メチレン基、炭素数２〜６のアルキレン基、フェニレン基、ナフチレン基、ピリジレン基、ピリミジニレン基又はトリアジニレン基であり、炭素原子が有する水素原子の少なくとも１つが置換されていてもよい。Ｂは、それぞれ独立に、単結合、−ＣＯ−、−ＣＯＯ−又は−ＣＯ−ＮＨ−である。Ｒ^１は、ハロゲン原子、炭素数１〜６のアルキル基、アルコキシ基又はフルオロアルキル基である。ｍは０〜３の整数であり、ｍが２又は３の場合、複数のＲ^１はそれぞれ独立して上記定義を有する。） In the present invention, as the diamine, a compound represented by the following formula (2) may be used, and more specifically, as A in the following formula (2), each independently represents a phenylene group or a substituted phenylene group. A certain compound may be used.

(In Formula (2), each A is independently a single bond, a methylene group, an alkylene group having 2 to 6 carbon atoms, a phenylene group, a naphthylene group, a pyridylene group, a pyrimidinylene group, or a triazinylene group, and has a carbon atom. At least one of hydrogen atoms may be substituted, B is each independently a single bond, —CO—, —COO— or —CO—NH—, R ¹ is a halogen atom, 6 is an alkyl group, an alkoxy group or a fluoroalkyl group, m is an integer of 0 to 3, and when m is 2 or 3, a plurality of R ^{1 s} independently have the above definition.)

  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 IPS liquid crystal display elements.

（式（３）中、Ｂは、それぞれ独立に、単結合、−ＣＯ−、−ＣＯＯ−又は−ＣＯ−ＮＨ−である。Ｒ^１及びＲ^２は、それぞれ独立に、ハロゲン原子、炭素数１〜６のアルキル基、アルコキシ基又はフルオロアルキル基である。ｍは０〜３の整数であり、ｍが２又は３の場合、複数のＲ^１はそれぞれ独立して上記定義を有する。ｒは、それぞれ独立に、０〜４の整数であり、Ｒ^２が複数存在する場合、それらＲ^２はそれぞれ独立して上記定義を有する。） According to the present invention, a compound represented by the following formula (3) is provided. In addition, a polymer (polyamic acid and imidized polymer thereof) obtained by reacting this compound with tetracarboxylic dianhydride is provided.

(In Formula (3), B is each independently a single bond, —CO—, —COO—, or —CO—NH—. R ¹ and R ² each independently represent a halogen atom or a carbon number of 1; An alkyl group, an alkoxy group or a fluoroalkyl group of ˜6, wherein m is an integer of 0 to 3, and when m is 2 or 3, a plurality of R ^{1 s} independently have the above definition. And each independently represents an integer of 0 to 4, and when a plurality of R ² are present, each R ² independently has the above definition.)

  The liquid crystal aligning agent of this invention contains the polymer of at least any one of the polyamic acid obtained by making tetracarboxylic dianhydride and diamine react, and its imidized polymer. Hereinafter, the liquid crystal aligning agent of this invention is demonstrated in detail.

（式（１）中、Ｒ^１は、ハロゲン原子、炭素数１〜６のアルキル基、アルコキシ基又はフルオロアルキル基である。ｍは０〜３の整数であり、ｍが２又は３の場合、複数のＲ^１はそれぞれ独立して上記定義を有する。「＊」は結合手を示す。）
で表される構造を有する。 <Polyamic acid>
At least a part of the polyamic acid contained in the liquid crystal aligning agent of the present invention has the following formula (1)

(In Formula (1), R ¹ is a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group or a fluoroalkyl group. M is an integer of 0 to 3, and when m is 2 or 3, (Several R ^{1 s} independently have the above definition. “*” Represents a bond.)
It has the structure represented by these.

In R ¹ of the above formula (1), examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
The alkyl group having 1 to 6 carbon atoms may be linear or branched, and specifically includes methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl. Group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, n-hexyl group, isohexyl group and the like.

Examples of the fluoroalkyl group having 1 to 6 carbon atoms in R ¹ include those obtained by substituting at least one hydrogen atom of the above-described groups as the alkyl group having 1 to 6 carbon atoms with a fluorine atom. In addition, examples of the alkoxy group having 1 to 6 carbon atoms include those in which the groups mentioned as the alkyl group having 1 to 6 carbon atoms are bonded to an oxygen atom. Groups and the like.
m is an integer of 0 to 3, preferably an integer of 0 to 2, and more preferably 0. In addition, when m is 2 or 3, several R < ¹ > may be the same or different, respectively.

  The bonding position of the two NH groups in the pyridine ring of the above formula (1) is not particularly limited, and is, for example, 2,6-position, 2,5-position, 2,4-position, 3,5-position, etc. be able to. Among these, the bonding position of two NH groups is preferably 2,6-position or 2,4-position, and more preferably 2,6-position.

  In order to obtain a polyamic acid having a structure represented by the above formula (1), for example, a tetracarboxylic dianhydride having a structure represented by the above formula (1) is reacted with a diamine, or Tetracarboxylic dianhydride is reacted with a diamine having a structure represented by the above formula (1). Of these, the latter is preferred.

[Tetracarboxylic dianhydride]
Examples of tetracarboxylic dianhydrides for synthesizing polyamic acid in the present invention include aliphatic tetracarboxylic dianhydrides, alicyclic tetracarboxylic dianhydrides, aromatic tetracarboxylic dianhydrides, and the like. Can do.

Specifically, examples of the aliphatic tetracarboxylic dianhydride include 1,2,3,4-butanetetracarboxylic dianhydride;
Examples of the alicyclic tetracarboxylic dianhydride include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 1,3,3a, 4,5,9b-Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5 9b-Hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 3-oxabicyclo [3.2.1 ] Octane-2,4-dione-6-spiro-3 ′-(tetrahydrofuran-2 ′, 5′-dione), 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3- Cyclohexene-1,2-dicarboxylic acid Anhydride, 3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-dianhydride, 2,4,6,8-tetracarboxybicyclo [3.3.0] octane- 2: 3,5: 6-dianhydride, 2,4,6,8-tetracarboxybicyclo [3.3.0] octane-2: 4,6: 8-dianhydride, 4,9-dioxa Tricyclo [5.3.1.0 ^2,6 ] undecane-3,5,8,10-tetraone, 1S, 2S, 4R, 5R-cyclohexanetetracarboxylic dianhydride, 1R, 2S, 4S, 5R- Cyclohexanetetracarboxylic dianhydride and the like;

Examples of the aromatic tetracarboxylic dianhydride include pyromellitic dianhydride (PMDA), 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4 ′. -Benzophenone tetracarboxylic dianhydride, 1,4,5,8-naphthalene tetracarboxylic dianhydride and the like;
In addition to the above, tetracarboxylic dianhydrides described in JP 2010-97188 A, other than those described above, can be used. In addition, said tetracarboxylic dianhydride can be used individually by 1 type or in combination of 2 or more types.

  The tetracarboxylic dianhydride used to synthesize the polyamic acid preferably includes an alicyclic tetracarboxylic dianhydride. In this case, the ratio of the alicyclic tetracarboxylic dianhydride is preferably 10 to 100 mol%, and preferably 50 to 100 mol, based on the total amount of tetracarboxylic dianhydride used for the synthesis of the polyamic acid. % Is more preferable, and 80 to 100 mol% is still more preferable. By setting it as the said range, in the produced liquid crystal display element, while being able to maintain a high voltage retention in a high temperature environment, a low afterimage characteristic can be made more favorable.

（式（２）中、Ａは、それぞれ独立に、単結合、メチレン基、炭素数２〜６のアルキレン基、フェニレン基、ナフチレン基、ピリジレン基、ピリミジニレン基又はトリアジニレン基であり、炭素原子が有する水素原子の少なくとも１つが置換されていてもよい。Ｂは、それぞれ独立に、単結合、−ＣＯ−、−ＣＯＯ−又は−ＣＯ−ＮＨ−である。Ｒ^１、ｍは、上記式（１）のＲ^１、ｍとそれぞれ同義である。） [Diamine]
The diamine used for synthesizing the polyamic acid in the present invention preferably contains a compound represented by the following formula (2) (hereinafter also referred to as diamine (D-1)).

(In Formula (2), each A is independently a single bond, a methylene group, an alkylene group having 2 to 6 carbon atoms, a phenylene group, a naphthylene group, a pyridylene group, a pyrimidinylene group, or a triazinylene group, and has a carbon atom. At least one of the hydrogen atoms may be substituted, B is each independently a single bond, —CO—, —COO— or —CO—NH—, wherein R ¹ and m are the formula (1) And R ¹ and m are the same as each other.)

The ^{R 1} in the formula (2), can be directly applied to the description of ^{R 1} in the formula (1). Further, the description of the above formula (1) can be applied as it is to the bonding position of the NH group in the pyridine ring.
B is a single bond, —CO—, —COO— or —CO—NH—, and two Bs in the formula (2) may be the same or different. Preferably, B is a single bond.

Among A in the above formula (2), the alkylene group having 2 to 6 carbon atoms may be linear or branched. For example, an ethylene group, a 1,3-propylene group, 1, 2-propylene group, 1,4-butylene group and the like;
Examples of the phenylene group include 1,3-phenylene group and 1,4-phenylene group;
As the naphthylene group, 1,4-naphthylene group, 1,5-naphthylene group and the like;
Examples of the pyridylene group include 2,4-pyridylene group and 2,5-pyridylene group;
Examples of the pyrimidinylene group include a 2,5-pyrimidinylene group;
Examples of the triazinylene group include 2,4-triazinylene group;
Each can be mentioned. Examples of the substituent that these groups may have include a halogen atom such as a fluorine atom and a chlorine atom, a cyano group, and the group exemplified for R ¹ above.

（式（３）中、Ｂは、それぞれ独立に、単結合、−ＣＯ−、−ＣＯＯ−又は−ＣＯ−ＮＨ−である。Ｒ^２は、それぞれ独立に、ハロゲン原子、炭素数１〜６のアルキル基、アルコキシ基又はフルオロアルキル基である。ｒは、それぞれ独立に、０〜４の整数であり、Ｒ^２が複数存在する場合、それらＲ^２はそれぞれ独立して上記定義を有する。Ｒ^１、ｍは、上記式（１）のＲ^１、ｍとそれぞれ同義である。） Among these, A is preferably a substituted or unsubstituted phenylene group. That is, the diamine in the present invention preferably contains a compound represented by the following formula (3) (hereinafter also referred to as diamine (D-1-1)). By including diamine (D-1-1) as the diamine in the present invention, in the liquid crystal alignment film to be formed, the interaction with the benzene ring of the liquid crystal molecules is likely to be induced, and the liquid crystal alignment is further improved. Can be good.

(In Formula (3), B is each independently a single bond, —CO—, —COO—, or —CO—NH—. R ² is independently a halogen atom or a C 1-6 carbon atom. alkyl group, is .r an alkoxy group or a fluoroalkyl group, each independently, an integer from 0 to 4, .R ¹ having the above-defined cases, they R ² are each independently of R ² there are a plurality And m have the same meanings as R ¹ and m in the above formula (1), respectively.

Examples of R ^{2 in the} above formula (3) include the same groups as those exemplified for R ¹ in the above formula (1).
As r, 0-2 are preferable and 0 is more preferable.
In the benzene ring bonded to B, the bonding position of the primary amino group is not particularly limited, but is preferably 3-position or 4-position with respect to B, more preferably 4-position.

  Specific examples of the diamine (D-1) include 2,6-bis (4-aminoanilino) pyridine, 2,4-bis (4-aminoanilino) pyridine, 2,6-bis (3-aminoanilino) pyridine, 4-bis (3-aminoanilino) pyridine is preferred, and among these, 2,6-bis (4-aminoanilino) pyridine is particularly preferred. By using at least one of these compounds, the structure of “—NH-pyridine ring—NH—” is introduced into the main chain of the polyamic acid. Thereby, when a liquid crystal display element is produced using the formed liquid crystal alignment film, it is considered that the voltage holding ratio characteristic and the low afterimage characteristic of the liquid crystal display element in a high temperature environment can be further enhanced. .

  As the diamine for synthesizing the polyamic acid in the present invention, only the diamine (D-1) represented by the above formula (2) may be used, or another diamine is used in combination with the diamine (D-1). May be.

Examples of other diamines that can be used here include aliphatic diamines, alicyclic diamines, aromatic diamines, and diaminoorganosiloxanes shown below. 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;

（式（Ａ−１）中、Ｘ^Ｉ及びＸ^ＩＩは、それぞれ、単結合、−Ｏ−又は−ＣＯＯ−であり、Ｒ^Ｉは、炭素数１〜３のアルカンジイル基であり、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、ｎは０又は１である。ただし、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； 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, 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) Suaniline, 4,4 ′-(m-phenylenediisopropylidene) bisaniline, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, 2,6-diaminopyridine 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminoacridine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, N-ethyl-3,6-diaminocarbazole N-phenyl-3,6-diaminocarbazole, N, N′-bis (4-aminophenyl) -benzidine, N, N′-bis (4-aminophenyl) -N, N′-dimethylbenzidine, 1, 4-bis- (4-aminophenyl) -piperazine, 3,5-diaminobenzoic acid, dodecanoxy-2,4-diaminobenzene, teto Decanoxy-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, cholestenyl 3,5-diaminobenzoate, 3,5-diaminobenzene Lanostanyl perfate, 3,6-bis (4-aminobenzoyloxy) cholestane, 3,6-bis (4-aminophenoxy) cholestane, 4- (4′-trifluoromethoxybenzoyloxy) cyclohexyl-3,5- Diaminobenzoate, 4- (4′-trifluoromethylbenzoyloxy) cyclohexyl-3,5-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) cyclohexa 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 (A-1)

(In Formula (A-1), X ^I and X ^II are each a single bond, —O— or —COO—, R ^I is an alkanediyl group having 1 to 3 carbon atoms, and a is 0. Or b is an integer of 0 to 2, c is an integer of 1 to 20, and n 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 other diamines described in JP2010-97188A. Can be used.

^-X I in the above formula ^{(A-1) - (R} I -X II) n - , as the divalent group represented alkanediyl group having 1 to 3 carbon atoms, * - O -, * - COO — Or * —O—CH ₂ CH ₂ —O— (however, a bond marked with “*” binds to a diaminophenyl group) is preferable. Specific examples of the group C _c H _{2c + 1} — 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, Examples thereof include an n-eicosyl group. The two primary amino groups in the diaminophenyl group are preferably in the 2,4-position or 3,5-position with respect to the other groups.

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

  The ratio of the diamine (D-1) to the total amount of diamine is preferably 10 to 100 mol% from the viewpoint of maintaining a high voltage holding ratio in a high temperature environment and improving the low afterimage characteristics, More preferably, it is -100 mol%, and it is still more preferable that it is 80-100 mol%.

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

Examples of molecular weight regulators include acid monoanhydrides, monoamine compounds, 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.

（式中、Yはハロゲン原子である。Ｒ^１、Ｒ^２、ｍ及びｒは、それぞれ上記式（３）におけるＲ^１、Ｒ^２、ｍ及びｒの定義と同じである。） <Synthesis of diamine (D-1-1)>
The diamine (D-1-1), which is a novel compound represented by the above formula (3), can be appropriately produced by a conventional method of organic chemistry. Specifically, when B is a single bond compound in the above formula (3), for example, first, by reacting the compound (M-1) represented by the following formula with the compound (M-2), Intermediate (M-3) is obtained (see the following reaction formula (I)).

(In the formula, Y is a halogen atom. R ¹ , R ² , m and r are the same as defined for R ¹ , R ² , m and r in the above formula (3), respectively.)

  Examples of the halogen atom for Y include a bromine atom, a chlorine atom, an iodine atom, and a fluorine atom. Among these, a bromine atom is preferable from the viewpoint of reactivity.

The reaction of the reaction formula (I) is preferably performed using a catalyst such as a palladium catalyst in the presence of a base, and in that case, it is preferable to further use a phosphine compound.
Examples of the palladium catalyst used in the above reaction include tris (dibenzylidene) acetone dipalladium, Pd (PPh ₃ ) ₄ , PdCl ₂ (PPh ₃ ) ₂ , Pd (OAc) ₂ , tris (dibenzylideneacetone) dipalladium. A chloroform complex etc. are mentioned.
Examples of the phosphine compound include 2- (di-tert-butylphosphino) biphenyl, tri (tert-butyl) phosphine, tricyclohexylphosphine, 1,1′-bis (di-tert-butylphosphino) ferrocene, , 2′-bis (di-tert-butylphosphino) -1,1′-binaphthyl, 2-di-tert-butylphosphino-2 ′, 4 ′, 6′-triisopropylbiphenyl, 2- (dicyclohexylphosphine Fino) biphenyl and the like.
Examples of the base include sodium carbonate, potassium carbonate, sodium hydrogen carbonate, sodium hydroxide, potassium hydroxide, barium hydroxide, sodium ethoxide, sodium tert-butoxide, sodium acetate and the like.

  What is necessary is just to set the reaction temperature of Reaction formula (I) suitably according to the reaction method, but it is preferable that it is 0-150 degreeC, and it is more preferable that it is 80-150 degreeC. Examples of the organic solvent used in the reaction include toluene.

（式中、Ｒ^１、Ｒ^２、ｍ及びｒは、それぞれ上記式（３）におけるＲ^１、Ｒ^２、ｍ及びｒの定義と同じである。） Next, the intermediate (M-3) is subjected to reduction of the nitro group and reductive removal of the hydroxyl group under catalytic reduction conditions. Thereby, diamine (D-1-1) which is a compound represented by the said Formula (3) can be obtained (refer following Reaction formula (II)).

(In the formula, R ¹ , R ² , m and r are the same as the definitions of R ¹ , R ² , m and r in the above formula (3), respectively).

The reaction of the reaction formula (II) is preferably performed at −20 to 150 ° C., more preferably at 0 to 120 ° C. using a catalyst such as nickel, palladium-carbon, PtO ₂ , Pd (OH) _2. preferable. Examples of the solvent used for the reaction include tetrahydrofuran, toluene, N, N-dimethylformamide, N, N-dimethylacetamide, 1-methyl-2-pyrrolidone and the like.

<Synthesis of polyamic acid>
The polyamic acid in the present invention is obtained by, for example, reacting a diamine containing a compound represented by the above formula (2), preferably a compound represented by the above formula (3), with the above tetracarboxylic dianhydride. Can be obtained. The ratio of the tetracarboxylic dianhydride and the diamine used in the polyamic acid synthesis reaction is 0.2 to 2 for the tetracarboxylic dianhydride acid anhydride group to 1 equivalent of the amino group of the diamine. The ratio which becomes an equivalent is preferable, and the ratio which becomes 0.3-1.2 equivalent is still more preferable.

  The polyamic acid synthesis reaction is preferably carried out in an organic solvent. The reaction temperature at this time is preferably −20 ° C. to 150 ° C., more preferably 0 to 100 ° C. Moreover, it is preferable that reaction time is 0.1 to 24 hours, and it is more preferable that it is 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. It is.

  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 for the preparation of the liquid crystal aligning agent as it is, or may be used for the preparation of the liquid crystal aligning agent after isolating the polyamic acid contained in the reaction solution. Or you may use for preparation of a liquid crystal aligning agent, after refine | purifying the isolated polyamic acid. Isolation and purification of the polyamic acid can be performed according to known methods.

<Imidized polymer>
The imidized polymer (polyimide) in the present invention can be obtained by dehydrating and ring-closing the synthesized polyamic acid to imidize it. In this case, the reaction solution obtained by dissolving the polyamic acid may be used for the dehydration ring-closing reaction as it is, or the polyamic acid contained in the reaction solution may be isolated and then used for the dehydration ring-closing reaction. Alternatively, the isolated polyamic acid may be purified and then subjected to a dehydration ring closure reaction.

  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 rate of 30% or more, more preferably 50 to 99%, and more preferably 65 to 99%. This imidation ratio represents the ratio of the number of imide ring structures to the total of the number of polyimide amic acid structures and the number of imide ring structures in percentage. Here, a part of the imide ring may be an isoimide ring.

  The polyamic acid is preferably dehydrated and closed by heating the polyamic acid, or by dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydrating ring-closing catalyst to the solution, and heating the solution as necessary. . Of these, the latter method is preferred.

  In the method of adding a dehydrating agent and a dehydrating ring-closing catalyst to the polyamic acid solution, for example, an acid anhydride such as acetic anhydride, propionic anhydride, or trifluoroacetic anhydride can be used as the dehydrating agent. It is preferable that the usage-amount of a dehydrating agent shall be 0.01-20 mol with respect to 1 mol of the amic acid structure of a polyamic acid. As the dehydration ring closure catalyst, for example, tertiary amines such as pyridine, collidine, lutidine, and triethylamine 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>
The polyamic acid or imidized polymer (hereinafter also referred to as a specific polymer) in the present invention obtained as described above has a solution viscosity of 20 to 800 mPa · s when this is a 10% by weight solution. Preferably, it has a solution viscosity of 30 to 500 mPa · s. In addition, the solution viscosity (mPa · s) of the above polymer is based on a polymer solution having a concentration of 10% by weight prepared using a good solvent for the polymer (eg, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.). The value measured at 25 ° C. using an E-type rotational viscometer.

<Other additives>
Although the liquid crystal aligning agent of this invention contains a specific polymer as mentioned above, it may contain the other component as needed. Examples of such other components include other polymers other than the specific polymer, compounds having at least one epoxy group in the molecule (hereinafter referred to as “epoxy compound”), functional silane compounds, and the like. it can.

[Other polymers]
Other polymers can be used to improve solution and electrical properties. Such other polymer is a polymer other than the specific polymer, for example, a polyamic acid (hereinafter referred to as “polyamic acid”) obtained by reacting a diamine not containing the compound represented by the formula (2) with tetracarboxylic dianhydride. "Other polyamic acid"), polyimide obtained by dehydrating and ring-closing the other polyamic acid (hereinafter referred to as "other polyimide"), polyamic acid ester, polyester, polyamide, polysiloxane, cellulose derivative, polyacetal, Examples thereof include polystyrene derivatives, poly (styrene-phenylmaleimide) derivatives, poly (meth) acrylates, and the like. Of these, other polyamic acids or other polyimides are preferred, and other polyamic acids are more preferred. In addition, the compound used in order to synthesize | combine a specific polymer can be mentioned as tetracarboxylic dianhydride and diamine used in order to synthesize | combine another polyamic acid or another polyimide.

  When other polymers are added to the liquid crystal aligning agent, the blending ratio is preferably 50% by weight or less, more preferably 0.1 to 40% by weight, more preferably 0.1% by weight to the total amount of the polymer in the liquid crystal aligning agent. 1 to 30% by weight is more preferable.

[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 - cyclohexyl amine may be mentioned as preferred.

  When these epoxy compounds are added to the liquid crystal aligning agent, the blending ratio is preferably 40 parts by weight or less, more preferably 0.1 to 30 parts by weight with respect to 100 parts by weight of the total of the polymers contained in the liquid crystal aligning agent. preferable.

[Functional silane compounds]
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, and 3-glycidoxypropyl triethoxy silane and the like.

  When these functional silane compounds are added to the liquid crystal aligning agent, the blending ratio is preferably 2 parts by weight or less, more preferably 0.02 to 0.2 parts by weight, based on 100 parts by weight of the total polymer.

[Organic solvent]
The liquid crystal aligning agent of the present invention is constituted by dissolving a specific polymer and other additives optionally blended as necessary, preferably dissolved in an organic solvent.

  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 combination of two or more.

  The solid content concentration in the liquid crystal aligning agent (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, etc. It is in the range of 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 solid content concentration is less than 1% by weight, it is difficult to obtain a good liquid crystal alignment film because the film thickness is too small. On the other hand, when the solid content concentration exceeds 10% by weight, it is difficult to obtain a good liquid crystal alignment film due to excessive film thickness, and the viscosity of the liquid crystal aligning agent may increase, resulting in poor coating characteristics. There is.

The particularly preferable solid content concentration range varies depending on the method used when applying the liquid crystal aligning agent to the substrate. For example, when the spinner method is used, a solid content concentration of 1.5 to 6.0% by weight is particularly preferable. 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 the liquid crystal aligning film formed of said liquid crystal aligning agent. The operation mode of 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. Among them, it is particularly preferable to apply to the IPS 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 (1) to (3). In step (1), the substrate to be used varies depending on the desired operation mode. Steps (2) and (3) are common to each operation mode.

[Step (1): Formation of coating film]
First, the liquid crystal aligning agent of this invention is apply | coated on a board | substrate, Then, a coating film is formed on a board | substrate by heating an application surface.

  (1-1) When manufacturing a TN type, STN type, or VA type liquid crystal display element, a pair of two substrates provided with a patterned transparent conductive film is used as a pair on each transparent conductive film formation surface. The liquid crystal aligning agent of the present invention is preferably applied by an offset printing method, a spin coating method, a roll coater method, or an ink jet printing method, and then each coated surface is heated (preferably pre-heated (pre-baked) and fired (post-baked). ) To form a coating film.

As the substrate, for example, glass such as float glass or soda glass; a transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, poly (cycloaliphatic olefin) can be used.
As a transparent conductive film provided on one surface of the substrate, an NESA film (registered trademark of PPG, USA) made of tin oxide (SnO ₂ ), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ), etc. Can be used. In order to obtain a patterned transparent conductive film, for example, a method of forming a pattern by photo-etching after forming a transparent conductive film without a pattern, or a method of using a mask having a desired pattern when forming a transparent conductive film And so on.

  When applying the liquid crystal aligning agent, in order to further improve the adhesion between the substrate surface and the transparent conductive film and the coating film, a functional silane compound or functional titanium is formed on the surface of the substrate surface on which the coating film is to be formed. You may give the pretreatment which apply | coats a compound etc. previously.

  After coating the liquid crystal aligning agent, the coated surface is then preheated (prebaked) and further baked (postbaked) to form a coating film. The pre-bake conditions are, for example, 0.1 to 5 minutes at 40 to 120 ° C., and the post-bake conditions are preferably 120 to 300 ° C., more preferably 150 to 250 ° C., preferably 5 to 200 minutes, more preferably 10 to 100 minutes. The film thickness of the formed coating film is preferably 0.001-1 μm, more preferably 0.005-0.6 μm.

  (1-2) When manufacturing an IPS type liquid crystal display element, a conductive film forming surface of a substrate provided with a comb-shaped transparent conductive film and a surface of a counter substrate provided with no conductive film Next, the liquid crystal aligning agent of this invention is apply | coated, respectively, Then, a coating film is formed by heating each application | coating 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 is as described in (1-1 ).

  In both cases (1-1) and (1-2), after applying a liquid crystal aligning agent on the substrate, a coating film to be an alignment film is formed by removing the organic solvent. At this time, when the polymer contained in the liquid crystal aligning agent of the present invention is a polyamic acid or an imidized polymer having an imide ring structure and an amic acid structure, heating is further performed after the coating film is formed. By doing so, the dehydration ring-closing reaction may be advanced to form a more imidized coating film.

[Step (2): rubbing treatment]
When manufacturing a TN type, STN type, 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 as mentioned above can be used as a liquid crystal aligning film as it is, you may give said rubbing process.

[Step (3): Construction of liquid crystal cell]
A liquid crystal cell is constructed by arranging the pair of substrates on which the liquid crystal alignment film is formed as described above so that the rubbing directions of the liquid crystal alignment films of the two substrates are orthogonal or antiparallel. In order to construct a liquid crystal cell, for example, the following two methods can be mentioned.
In the first 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. Next, liquid crystal is injected and filled in the cell gap defined by the substrate surface and the sealing agent, and then the injection hole is sealed to construct a liquid crystal cell.
The second method is a method called an ODF (One Drop Fill) method. In this method, first, for example, an ultraviolet light curable sealing material is applied to a predetermined location on one of the two substrates on which the liquid crystal alignment film is formed, and liquid crystal is further dropped onto the liquid crystal alignment film surface. After that, the other substrate is bonded so that the liquid crystal alignment film faces each other. Next, a liquid crystal cell is constructed by irradiating the entire surface of the substrate with ultraviolet light to cure the sealant.

  As the sealing agent, for example, an epoxy resin containing a curing agent and aluminum oxide spheres as a spacer can be used.

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

  Then, a polarizing plate is bonded to the outer surface of the constructed liquid crystal cell so that the polarization direction thereof matches or is orthogonal to the rubbing direction of the liquid crystal alignment film formed on each substrate. Thereby, a liquid crystal display element can be obtained. As a polarizing plate to be bonded to the outer surface of the liquid crystal cell, a polarizing film or an H film itself in which a polarizing film called an “H film” in which iodine is absorbed while stretching and aligning polyvinyl alcohol is sandwiched between cellulose acetate protective films The polarizing plate which consists of can be mentioned.

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

<Synthesis of diamine>
[Synthesis Example 1]
Compound (d-1) was synthesized according to the following scheme 1. In addition, the required amount in the following synthesis example of polyamic acid was ensured by repeating with the following scale as needed.

  In a 1 L three-necked flask equipped with a condenser and a thermometer, in a nitrogen atmosphere, 33.1 g of 4-nitroaniline, 23.7 g of 2,6-dibromopyridine, 3.7 g of tris (dibenzylidene) acetone dipalladium, 2- (Di-tert-butylphosphino) biphenyl (2.4 g), sodium tert-butoxide (28.8 g), and toluene (500 mL) were mixed, and the mixture was reacted by heating and stirring at 110 ° C. for 12 hours. After allowing to cool, the precipitate was collected by filtration. After thoroughly washing with distilled water and ethanol, it was dried to obtain 28.8 g of intermediate (yield 82%).

  Subsequently, 28.8 g of an intermediate, 5.0 g of Pd / C, 400 ml of tetrahydrofuran, and 100 ml of ethanol were mixed and stirred in a 1 L three-necked flask equipped with a condenser and a thermometer in a nitrogen atmosphere. After 41 ml of hydrazine monohydrate was added dropwise and stirred at 25 ° C. for 1 hour, the reaction was conducted by heating and stirring at 70 ° C. for 6 hours. After adding 100 ml of N, N-dimethylformamide to the reaction solution, Pd / C was removed by Celite filtration. The filtrate and 300 ml of distilled water were mixed and the precipitate was collected by filtration. After thoroughly washing with distilled water and ethanol, it was dried to obtain 18.4 g of diamine compound (d-1) (yield 77%).

<Synthesis of polyamic acid>
[Synthesis Example 2]
To 2800 g of N-methyl-2-pyrrolidone, 291 g (1.0 mol) of compound (d-1) as diamine and 1,2,3,4-cyclobutanetetracarboxylic dianhydride as tetracarboxylic dianhydride 196 g (1.0 mol) was dissolved and reacted at 40 ° C. for 4 hours. Thereby, a solution containing 15% by weight of polyamic acid (PA-1) was obtained. The solution was diluted to 10% by weight and the viscosity was measured, and the result was 58 mPa · s.

[Synthesis Examples 3-8, Comparative Synthesis Examples 1-6]
The polyamic acid (PA-2) to (PA-7), (PAR-) are the same as in Synthesis Example 1 except that the types of tetracarboxylic dianhydride and diamine and the number of moles used are as shown in Table 1 below. A solution containing 15% by weight of 1) to (PAR-6) was obtained.

In Table 1, the abbreviations of tetracarboxylic dianhydride and diamine are as follows.
[Tetracarboxylic dianhydride]
T-1: 2,3,5-tricarboxycyclopentyl acetic acid dianhydride T-2: pyromellitic dianhydride T-3: 1,2,3,4-cyclobutanetetracarboxylic dianhydride [diamine]
d-2: p-phenylenediamine d-3: 1,3-bis (4-aminophenoxy) benzene
d-4: 4-aminophenyl-4′-aminobenzoate d-5: 4,4′-diaminodiphenylamine d-6: 2,4-diaminodiphenylamine

<Preparation of liquid crystal aligning agent>
[Example 1]
Γ-butyrolactone (BL), N-methyl-2-pyrrolidone (NMP) and butyl cellosolve (BC) are added to the solution containing the polyamic acid (PA-1) obtained in Synthesis Example 2 above, and N as an epoxy compound is added. , N, N ′, N′-Tetraglycidyl-4,4′-diaminodiphenylmethane is added in an amount of 20 parts by weight with respect to a total of 100 parts by weight of the polymer and sufficiently stirred, and the solvent composition is BL: NMP: BC = The solution was 40:40:20 (weight ratio) and the solid concentration was 4.0% by weight. This solution was filtered using a filter having a pore size of 1 μm to obtain a liquid crystal aligning agent.

[Examples 2-7, Comparative Examples 1-6]
A liquid crystal aligning agent was prepared in the same manner as in Example 1 except that the type of polyamic acid was changed to any one of (PA-2) to (PA-7) and (PAR-1) to (PAR-6), respectively. .

<Manufacture of liquid crystal cells>
Each prepared liquid crystal aligning agent of Examples 1-7 and Comparative Examples 1-6 was apply | coated to the transparent electrode surface of the glass substrate with a transparent electrode which consists of an ITO film | membrane using a spin coater, on a 80 degreeC hotplate. After removing the solvent by heating (pre-baking) for 1 minute, it was heated (post-baking) for 10 minutes on a 200 ° C. hot plate to form a coating film having an average film thickness of 600 mm. This coating film was rubbed with a rubbing machine having a roll wrapped with a rayon cloth at a roll rotation speed of 1000 rpm, a stage moving speed of 25 mm / sec, and a hair foot indentation length of 0.4 mm to give liquid crystal alignment ability. . Then, ultrasonic cleaning was performed in ultrapure water for 1 minute, and then drying was performed 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, after applying an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm to one of the outer edges of the pair of substrates having the liquid crystal alignment film, the liquid crystal alignment film surfaces face each other, and The adhesive was cured by overlapping and pressing so that the rubbing directions in each alignment film were orthogonal. Next, a nematic liquid crystal (MLC-2042, manufactured by Merck & Co., Inc.) was filled between the pair of substrates from the liquid crystal inlet, and then the liquid crystal inlet was sealed with an acrylic photo-curing adhesive to produce a liquid crystal cell. .

<Evaluation of liquid crystal cell>
(1) Measurement of voltage holding ratio For the liquid crystal cell manufactured above, a voltage of 5 V was applied at a temperature of 90 ° C. with an application time of 60 microseconds and a span of 167 milliseconds, and then 167 milliseconds from the release of application. The subsequent voltage holding ratio (VHR) was measured. The measuring apparatus used was VHR-1 manufactured by Toyo Corporation. The case where the voltage holding ratio was 90% or more was evaluated as “good”, and the case where it was less than 90% was evaluated as “bad”.

(2) Measurement of residual DC Immediately after applying the 30 Hz / ± 3 V rectangular wave to which the offset voltage of 3 V was added at a temperature of 60 ° C. for 120 minutes and cutting the offset voltage of 3 V for the liquid crystal cell manufactured above. The residual DC voltage (V) remaining in the liquid crystal cell was measured by the flicker elimination method. A case where the residual DC voltage was 1V or less was evaluated as “good” and a case where the residual DC voltage was higher than 1V was evaluated as “bad”.

The results of the above (1) and (2) are shown in Table 2 below.

  As shown in Table 2, each of the liquid crystal cells of Examples 1 to 6 had good voltage holding characteristics in a high temperature environment and good residual DC characteristics. Among them, the liquid crystal cells of Examples 1 and 6 have a high voltage holding ratio at 90 ° C. of 94% or more and a measured residual DC voltage of 0.2 V or less, and voltage holding characteristics and low afterimage in a high temperature environment. Both properties were particularly excellent. On the other hand, in all of Comparative Examples 1 to 6, the voltage holding ratio was as low as less than 90%, and the residual DC voltage was as large as 1.2 V or more.

Claims (5)

Containing at least one polymer selected from the group consisting of polyamic acid obtained by reacting tetracarboxylic dianhydride and diamine and its imidized polymer;
The said polymer has a structure represented by following formula (1), The liquid crystal aligning agent characterized by the above-mentioned.

(In Formula (1), R ¹ is a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group or a fluoroalkyl group. M is an integer of 0 to 3, and when m is 2 or 3, (Several R ^{1 s} independently have the above definition. “*” Represents a bond.) The liquid crystal aligning agent according to claim 1, wherein the diamine contains a compound represented by the following formula (2).

(In Formula (2), each A is independently a single bond, a methylene group, an alkylene group having 2 to 6 carbon atoms, a phenylene group, a naphthylene group, a pyridylene group, a pyrimidinylene group, or a triazinylene group, and has a carbon atom. At least one of hydrogen atoms may be substituted, B is each independently a single bond, —CO—, —COO— or —CO—NH—, R ¹ is a halogen atom, 6 is an alkyl group, an alkoxy group or a fluoroalkyl group, m is an integer of 0 to 3, and when m is 2 or 3, a plurality of R ^{1 s} independently have the above definition.)   The liquid crystal aligning agent according to claim 2, wherein each A is independently a phenylene group or a substituted phenylene group.   The liquid crystal aligning film formed with the liquid crystal aligning agent of any one of Claims 1 thru | or 3.   A liquid crystal display device comprising the liquid crystal alignment film according to claim 4.