WO2011010619A1

WO2011010619A1 - Diamine compound, polyamic acid, polyimide, and liquid crystal aligning agent

Info

Publication number: WO2011010619A1
Application number: PCT/JP2010/062109
Authority: WO
Inventors: 徳俊三木; 悟志南; 雅章片山
Original assignee: 日産化学工業株式会社
Priority date: 2009-07-21
Filing date: 2010-07-16
Publication date: 2011-01-27
Also published as: KR20170110172A; TWI477478B; JP5729299B2; KR20120037493A; CN102574811A; JPWO2011010619A1; CN102574811B; KR102073458B1; TW201118062A

Abstract

Provided is a novel diamine compound useful as a raw material for a polyamic acid and/or polyimide. The polyamic acid or polyimide prepared using the diamine compound can constitute a liquid crystal aligning agent capable of forming a liquid crystal alignment film which has a high voltage holding ratio and which, even after long-time exposure to high temperature, achieves quick relaxation of a residual charge accumulated by DC voltage. Specifically provided are a novel dimaine compound represented by general formula [1], and a liquid crystal aligning agent which contains a polyamic acid and/or polyimide prepared using the diamine compound. In general formula [1], X¹ is –CO- or –CONH-; X² is a C_1-5 alkylene group or a nitrogen-containing nonaromatic heterocycle; and X³ is a five- or six-membered aromatic heterocycle which contains two nitrogen atoms and which may be substituted with a C_1-5 alkyl group.

Description

Diamine compound, polyamic acid, polyimide and liquid crystal alignment treatment agent

The present invention relates to a novel diamine compound useful as a raw material for a polymer used in a liquid crystal alignment film, a polyamic acid and a polyimide obtained using the same, and a liquid crystal alignment treatment agent. Furthermore, it is related with the liquid crystal display element which has a liquid crystal aligning film obtained from the said liquid-crystal aligning agent.

Currently, as a liquid crystal alignment film of a liquid crystal display element, a liquid crystal alignment treatment agent (also referred to as a liquid crystal alignment agent) mainly composed of a polyimide precursor such as polyamic acid or a solution of soluble polyimide is applied to a glass substrate and fired. A so-called polyimide-based liquid crystal alignment film is mainly used.

The liquid crystal alignment film is used for the purpose of controlling the alignment state of the liquid crystal. However, as the liquid crystal display elements have become higher in definition, the liquid crystal alignment film used has a high voltage holding ratio and a direct current voltage has been applied due to demands for suppressing the decrease in contrast of the liquid crystal display elements and reducing the afterimage phenomenon. The characteristic that the residual charge at the time is small and / or the residual charge accumulated by the DC voltage is quickly relaxed has become increasingly important.

In a polyimide-based liquid crystal alignment film, a liquid crystal aligning agent containing a tertiary amine having a specific structure in addition to polyamic acid or an imide group-containing polyamic acid was used as a short time until the afterimage generated by direct current voltage disappears. There are known ones (for example, see Patent Document 1) and those using a liquid crystal aligning agent containing a soluble polyimide using a specific diamine compound having a pyridine skeleton as a raw material (for example, see Patent Document 2). In addition to polyamic acid and its imidized polymer, a compound containing one carboxylic acid group in the molecule, assuming that the voltage holding ratio is high and the time until the afterimage generated by direct current voltage disappears is short , Using a liquid crystal aligning agent containing a very small amount of a compound selected from a compound containing one carboxylic anhydride group in the molecule and a compound containing one tertiary amine group in the molecule (for example, a patent Document 3) is known.

However, in recent years, large-screen, high-definition liquid crystal televisions have been widely put into practical use, and liquid crystal display elements in such applications are more effective against afterimages than conventional displays that mainly display characters and still images. The requirements are becoming stricter, and characteristics that can withstand long-term use in harsh usage environments are required. Therefore, the liquid crystal alignment film to be used has to be more reliable than conventional liquid crystal alignment films. The electrical characteristics of the liquid crystal alignment film are not only good in initial characteristics but also, for example, at a high temperature for a long time. There is a need to maintain good properties even after exposure.

JP-A-9-316200 JP-A-10-104633 JP-A-8-76128

An object of the present invention is to provide a liquid crystal alignment treatment agent capable of obtaining a liquid crystal alignment film having a high voltage holding ratio and capable of quickly relieving residual charges accumulated by a DC voltage even after being exposed to a high temperature for a long time. It is in providing the diamine compound which can be used as a raw material of the polyamic acid and / or polyimide (henceforth also referred to as a polymer).
Furthermore, an object of the present invention is to provide a liquid crystal alignment film having a high voltage holding ratio and capable of obtaining a liquid crystal alignment film in which residual charges accumulated by a DC voltage are quickly relaxed even after being exposed to a high temperature for a long time. It is an object of the present invention to provide a liquid crystal display device with high reliability that can withstand a long-term use in a treating agent and a severe use environment.

As a result of diligent research to achieve the above object, the present inventor has found a diamine compound having a specific novel structure, and a liquid crystal aligning agent containing a polymer obtained by using the diamine compound has the above-described properties. Found to achieve the purpose. The present invention is based on such knowledge and has the following gist.
(1) A diamine compound of the following formula [1].

(Wherein X ¹ represents —CO— or —CONH—, X ² represents an alkylene group having 1 to 5 carbon atoms or a non-aromatic heterocyclic ring containing a nitrogen atom, and X ³ represents 1 to 5 carbon atoms) It represents a 5-membered or 6-membered aromatic heterocycle containing two nitrogen atoms, which may be substituted with 5 alkyl groups.
(2) The diamine compound according to (1), wherein the aromatic heterocyclic ring is an imidazole ring, a pyrazine ring, or a pyrimidine ring.
(3) The diamine compound according to (1) or (2), wherein the non-aromatic heterocycle containing the nitrogen atom is a piperazine ring.
(4) Polyamic acid obtained by reacting the diamine component containing the diamine compound according to any one of (1) to (3) above and a tetracarboxylic dianhydride component, or a polyimide obtained by imidizing the polyamic acid .
(5) The polyamic acid according to (4) or the imidized polyamic acid according to (4) above, wherein 1 to 80 mol% of the diamine compound according to any one of (1) to (3) is contained in the diamine component Polyimide.
(6) The polyamic acid according to (4) or a polyimide obtained by imidizing the polyamic acid, wherein the diamine component contains a diamine compound containing a carboxyl group in the molecule.
(7) The diamine component contains 0.01 to 99 mol of a diamine compound having a carboxyl group in the molecule with respect to 1 mol of the diamine according to any one of (1) to (3) above. The polyamic acid as described in said (6) or the polyimide which imidized this polyamic acid.
(8) The polyamic acid according to the above (6) or (7), wherein the diamine compound having a carboxyl group in the molecule is a diamine represented by the following formula [2], or a polyimide obtained by imidizing the polyamic acid .

(In the formula [2], X ⁵ is an organic group having an aromatic ring having 6 to 30 carbon atoms, and n is an integer of 1 to 4.)
(9) A liquid crystal aligning agent containing at least one of the polyamic acid according to any one of (4) to (8) and a polyimide obtained by imidizing the polyamic acid, and a solvent.
(10) The liquid crystal aligning agent according to the above (9), wherein 5 to 80% by mass in the solvent is a poor solvent.
(11) A liquid crystal alignment film obtained from the liquid crystal aligning agent according to (9) or (10).
(12) A liquid crystal display device having the liquid crystal alignment film according to (11).

The diamine compound of the present invention is a novel diamine containing a specific structure containing a 5-membered or 6-membered aromatic heterocycle containing two nitrogen atoms in the side chain (hereinafter also referred to as a specific diamine compound). And can be obtained by a relatively simple method. The 5-membered or 6-membered aromatic heterocycle containing two nitrogen atoms in the specific diamine compound functions as an electron hopping site depending on the conjugated structure thereof, so that the polyamic acid and / or the specific acid using the specific diamine compound and / or The liquid crystal alignment film obtained from the polyimide polymer imidized with the polyamic acid can promote the movement of electric charge in the liquid crystal alignment film, has a high voltage holding ratio, and is exposed to a high temperature for a long time. Even in such a case, the residual charge accumulated by the DC voltage can be relaxed quickly.
Thus, a liquid crystal display element having a liquid crystal alignment film obtained from a liquid crystal alignment treatment agent containing a polyamic acid and / or a polyimide polymer using the diamine compound of the present invention is excellent in reliability and has a large screen. Therefore, it can be suitably used for high-definition liquid crystal televisions.

<Specific diamine compound>
The specific diamine compound of the present invention is represented by the following formula [1].

In the formula, X ¹ represents —CO— or —CONH—, X ² represents an alkylene group having 1 to 5 carbon atoms or a non-aromatic heterocyclic ring containing a nitrogen atom, and X ³ represents 1 to 5 carbon atoms. Represents a 5-membered or 6-membered aromatic heterocycle containing two nitrogen atoms, which may be substituted with an alkyl group.

The bonding position of the two amino groups (—NH ₂ ) in the formula [1] is not limited. Specifically, with respect to the linking group (X ¹ ) of the side chain, 2, 3 position, 2, 4 position, 2, 5 position, 2, 6 position, 3, 4 position on the benzene ring Position, 3, 5 positions. Among these, taking into consideration the reactivity when synthesizing the polyamic acid and the ease of synthesizing the diamine compound, the bonding positions of the two amino groups are positions 2, 4 and 2, 5 , 3, 5 are particularly preferred.
In the formula [1], X ¹ is —CO— or —CONH—.
In the formula [1], X ² is an alkylene group having 1 to 5 carbon atoms or a non-aromatic heterocyclic ring containing a nitrogen atom.
When X ² is an alkylene group having 1 to 5 carbon atoms, the alkylene group may be linear or branched. In particular, the alkylene group preferably has 1 to 3 carbon atoms.

Further, when X ² is a non-aromatic heterocyclic ring containing a nitrogen atom, examples include a pyrrolidine ring, a piperidine ring, a piperazine ring, a pyrazolidine ring, a quinuclidine ring, and an imidazolidine ring. In particular, a non-aromatic heterocyclic ring having a 5-membered ring or a 6-membered ring is preferable because good alignment can be obtained when a liquid crystal alignment film is used. In addition, when the non-aromatic heterocycle contains two nitrogen atoms, when a liquid crystal display device is used, ionic impurities in the liquid crystal are adsorbed at the liquid crystal alignment film interface, and the liquid crystal display device has good electrical characteristics. It is desirable to keep. From the above viewpoint, a piperazine ring is particularly preferable as the non-aromatic heterocyclic ring containing a nitrogen atom.
When X ² is bonded to a nitrogen atom in X ³ or an atom adjacent to the nitrogen atom, preferably a carbon atom, it is easy to achieve an effect of accelerating the relaxation of residual charges accumulated by a DC voltage in a liquid crystal display element. Therefore, it is preferable.

In the formula [1], X ³ is a 5-membered or 6-membered aromatic heterocyclic ring containing two nitrogen atoms, which may be substituted with an alkyl group having 1 to 5 carbon atoms. Examples of 5-membered or 6-membered aromatic heterocycles containing two nitrogen atoms include imidazole ring, pyrazole ring, pyrazine ring, pyrimidine ring and pyridazine ring. Among them, imidazole ring and pyrazine A ring or a pyrimidine ring is preferred. When the aromatic heterocycle in X ³ is substituted with an alkyl group, the alkyl group preferably has 1 to 3 carbon atoms.

Preferred specific combinations of X ¹ , X ² and X ³ in the above formula [1] are as shown in Table 1 and Table 2 below.

<Method for synthesizing specific diamine compound>
Although the method of manufacturing the specific diamine compound represented by Formula [1] of this invention is not specifically limited, The following method is mentioned as a preferable method.

The specific diamine compound of the present invention can be obtained by synthesizing a dinitro compound represented by the formula [3], further reducing the nitro group of the dinitro compound and converting it to an amino group. There is no particular limitation on the method for reducing the dinitro compound, and usually palladium-carbon, platinum oxide, Raney nickel, platinum black, rhodium-alumina, platinum sulfide carbon, etc. are used as a catalyst, ethyl acetate, toluene, tetrahydrofuran, dioxane, There is a method in which hydrogen gas, hydrazine, hydrogen chloride, or the like is used in an alcohol-based solvent. X ¹ , X ² , and X ³ in the formula [ ³ ] have the same definition as in the formula [1].

Dinitro compound represented by the formula [3], via the ^{X 1} against dinitrobenzene ^-X 2 -X ³ can be obtained by a method of attaching, for example, ^{X 1} is an amide bond (-CONH- ), A method of reacting dinitrobenzene chloride with an amino compound containing X ² and X ³ in the presence of alkali. In addition, when X ¹ is a reverse amide bond (—HNCO—), a method of reacting an amino group-containing nitrobenzene and an acid chloride containing X ² and X ³ in the presence of an alkali can be mentioned.

Examples of the dinitrobenzene acid chloride include 3,5-dinitrobenzoic acid chloride, 3,5-dinitrobenzoic acid, 2,4-dinitrobenzoic acid chloride, 3,5-dinitrobenzyl chloride, and 2,4-dinitrobenzyl chloride. Examples of the amino group-containing nitrobenzene include 2,4-dinitroaniline, 3,5-dinitroaniline, 2,6-dinitroaniline and the like. In consideration of availability of raw materials and reaction, one or more kinds can be selected and used.

<Polymer>
The polymer of the present invention is a polyamic acid obtained by reaction of a diamine component containing a specific diamine compound and tetracarboxylic dianhydride and a polyimide obtained by dehydrating and ring-closing this polyamic acid. Any of these polyamic acids and polyimides are useful as a polymer for obtaining a liquid crystal alignment film.
The liquid crystal alignment film obtained using the polymer of the present invention has a higher voltage holding ratio as the content ratio of the specific diamine compound in the diamine component increases, and even after being exposed to a high temperature for a long time, The residual charge accumulated by the DC voltage is alleviated faster.
For the purpose of enhancing the above properties, it is preferable that 1 mol% or more of the diamine component is the specific diamine compound. Furthermore, it is preferable that 5 mol% or more of a diamine component is a specific diamine compound, More preferably, it is 10 mol% or more.
Although 100 mol% of the diamine component may be a specific diamine compound, the specific diamine compound is preferably 80 mol% or less of the diamine component, more preferably, from the viewpoint of uniform coatability when applying the liquid crystal aligning agent. It is 40 mol% or less.

<Diamine compound having a carboxyl group in the molecule>
In the present invention, when a diamine compound having a carboxyl group in the molecule is used together with the specific diamine compound as the diamine component, an aromatic heterocyclic ring having two nitrogen atoms of the specific diamine compound is present in the molecule. When the carboxyl group of the diamine compound having a carboxyl group is linked with an electrostatic interaction such as salt formation or hydrogen bond, charge transfer occurs between the carboxyl group and the nitrogen-containing aromatic heterocycle. Therefore, the charge transferred to the nitrogen-containing aromatic heterocyclic moiety can efficiently move within and between the molecules of the copolymer, and as a result, the liquid crystal alignment treatment agent obtained in this case is a liquid crystal alignment film. In this case, the voltage holding ratio is high, and even after being exposed to a high temperature for a long time, there is an effect that the residual charge accumulated by the DC voltage is relaxed and faster.

The specific structure of the diamine compound having a carboxyl group in the molecule is not particularly limited, but a compound represented by the formula [2] is preferable.

In the formula [2], X ⁵ is an organic group having an aromatic ring having 6 to 30 carbon atoms, and n is an integer of 1 to 4.
If the formula [2] is specifically shown, the structures of the following formulas [3] to [7] can be mentioned.

In the formula [3], m1 is an integer of 1 to 4, and in the formula [4], X ⁶ is a single bond, —CH ₂ —, —C ₂ H ₄ —, —C (CH ₃ ) ₂ —, — CF ₂ —, —C (CF ₃ ) ₂ —, —O—, —CO—, —NH—, —N (CH ₃ ) —, —CONH—, —NHCO—, —CH ₂ O—, —OCH ₂ — , -COO-, -OCO-, -CON (CH ₃ )-, or -N (CH ₃ ) CO-, m2 and m3 are each an integer of 0 to 4, and m2 + m3 is an integer of 1 to 4 In the formula [5], m4 and m5 are each an integer of 1 to 5, and in the formula [6], X ⁷ is a linear or branched alkyl group having 1 to 5 carbon atoms, and m6 is 1 to 5. 5 is an integer, wherein [7], ^{X 8} is a single _{_{_{bond, -CH 2 -, - C 2}}} H 4 -, - C (CH 3) 2 -, - CF 2 -, - C (CF 3 _{_{2 -, - O -, -}} CO -, - NH -, - N (CH 3) -, - CONH -, - NHCO -, - CH 2 O -, - OCH2 -, - COO -, - OCO -, - CON (CH ₃ ) — or —N (CH ₃ ) CO—, and m7 represents an integer of 1 to 4.

In the structure of the formula [3] to the formula [7], a structure in which m1 is an integer of 1 to 2 in the formula [3], in the formula [4], X ⁶ is a single bond, —CH ₂ —, —C ₂ H ₄ —, —C (CH ₃ ) ₂ —, —O—, —CO—, —NH—, —N (CH ₃ ) —, —CONH—, —NHCO—, —COO—, or — A structure in which both m2 and m3 are integers of 1, and in formula [7], X ⁸ is a single bond, —CH ₂ —, —O—, —CO—, —NH—, —CONH—, —NHCO—, —CH ₂ O—, —OCH ₂ —, —COO—, or —OCO—, wherein m7 is an integer of 1 to 2.

Specific examples of the diamine compound represented by the formulas [3] to [7] include the compounds of the following formulas [8] to [18].

In the formula [17], X ⁹ is a single bond, —CH ₂ —, —O—, —CO—, —NH—, —CONH—, —NHCO—, —CH ₂ O—, —OCH ₂ —, —COO. In formula [18], X ¹⁰ is a single bond, —CH ₂ —, —O—, —CO—, —NH—, —CONH—, —NHCO—, —CH ₂ O —, —OCH ₂ —, —COO—, or —OCO—.

[Other diamine compounds]
In the present invention, as long as the effects of the present invention are not impaired, in addition to the specific diamine compound and the diamine compound having a carboxyl group in the molecule, other diamine compounds can be used in combination as a diamine component. Specific examples are given below.

p-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, m-phenylenediamine, 2,4-dimethyl-m-phenylenediamine, 2, 5-diaminotoluene, 2,6-diaminotoluene, 2,5-diaminophenol, 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4 , 6-diaminoresorcinol, 4,4′-diaminobiphenyl, 3,3′-dimethyl-4,4′-diaminobiphenyl, 3,3′-dimethoxy-4,4′-diaminobiphenyl, 3,3′-dihydroxy -4,4'-diaminobiphenyl, 3,3'-difluoro-4,4'-biphenyl, 3,3'-trifluoro Methyl-4,4′-diaminobiphenyl, 3,4′-diaminobiphenyl, 3,3′-diaminobiphenyl, 2,2′-diaminobiphenyl, 2,3′-diaminobiphenyl, 4,4′-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 2,2'-diaminodiphenylmethane, 2,3'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 3, 4'-diaminodiphenyl ether, 2,2'-diaminodiphenyl ether, 2,3'-diaminodiphenyl ether, 4,4'-sulfonyldianiline, 3,3'-sulfonyldianiline, bis (4-aminophenyl) silane, bis (3-aminophenyl) silane, dimethyl-bis (4-aminophenyl) Nyl) silane, dimethyl-bis (3-aminophenyl) silane, 4,4′-thiodianiline, 3,3′-thiodianiline, 4,4′-diaminodiphenylamine, 3,3′-diaminodiphenylamine, 3,4′- Diaminodiphenylamine, 2,2'-diaminodiphenylamine, 2,3'-diaminodiphenylamine, N-methyl (4,4'-diaminodiphenyl) amine, N-methyl (3,3'-diaminodiphenyl) amine, N-methyl (3,4'-diaminodiphenyl) amine, N-methyl (2,2'-diaminodiphenyl) amine, N-methyl (2,3'-diaminodiphenyl) amine, 4,4'-diaminobenzophenone, 3,3 '-Diaminobenzophenone, 3,4'-diaminobenzophenone, 1,4-diaminonaphthalene, 2,2'-diamy Benzophenone, 2,3'-diaminobenzophenone, 1,5-diaminonaphthalene, 1,6-diaminonaphthalene, 1,7-diaminonaphthalene, 1,8-diaminonaphthalene, 2,5-diaminonaphthalene, 2,6 diaminonaphthalene 2,7-diaminonaphthalene, 2,8-diaminonaphthalene, 1,2-bis (4-aminophenyl) ethane, 1,2-bis (3-aminophenyl) ethane, 1,3-bis (4-amino) Phenyl) propane, 1,3-bis (3-aminophenyl) propane, 1,4-bis (4aminophenyl) butane, 1,4-bis (3-aminophenyl) butane, bis (3,5-diethyl- 4-aminophenyl) methane, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenyl) benzene, 1,3-bis (4-aminophenyl) benzene, 1,4-bis (4-aminobenzyl) benzene, 1,3-bis (4-aminophenoxy) Benzene, 4,4 '-[1,4-phenylenebis (methylene)] dianiline, 4,4'-[1,3-phenylenebis (methylene)] dianiline, 3,4 '-[1,4-phenylenebis (Methylene)] dianiline, 3,4 ′-[1,3-phenylenebis (methylene)] dianiline, 3,3 ′-[1,4-phenylenebis (methylene)] dianiline, 3,3 ′-[1, 3-phenylenebis (methylene)] dianiline, 1,4-phenylenebis [(4-aminophenyl) methanone], 1,4-phenylenebis [(3-aminophenyl) methanone], 1,3-phenylenebis [( 4-aminophenyl) methanone], 1,3-phenylenebis [(3-aminophenyl) methanone], 1,4-phenylenebis (4-aminobenzoate), 1,4-phenylenebis (3-aminobenzoate), 1,3-phenylenebis (4-aminobenzoate), 1,3-phenylenebis (3-aminobenzoate), bis (4-aminophenyl) terephthalate, bis (3-aminophenyl) terephthalate, bis (4-aminophenyl) ) Isophthalate, bis (3-aminophenyl) isophthalate, N, N ′-(1,4-phenylene) bis (4-aminobenzamide), N, N ′-(1,3-phenylene) bis (4- Aminobenzamide), N, N ′-(1,4-phenylene) bis (3-aminobenzamide), N, N ′-(1,3-phenyl) Enylene) bis (3-aminobenzamide), N, N′-bis (4-aminophenyl) terephthalamide, N, N′-bis (3-aminophenyl) terephthalamide, N, N′-bis (4-amino) Phenyl) isophthalamide, N, N′-bis (3-aminophenyl) isophthalamide, 9,10-bis (4-aminophenyl) anthracene, 4,4′-bis (4-aminophenoxy) diphenylsulfone, 2, 2'-bis [4- (4-aminophenoxy) phenyl] propane, 2,2'-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2'-bis (4-aminophenyl) Hexafluoropropane, 2,2'-bis (3-aminophenyl) hexafluoropropane, 2,2'-bis (3-amino-4-methylphenyl) hex Safluoropropane, 2,2′-bis (4-aminophenyl) propane, 2,2′-bis (3-aminophenyl) propane, 2,2′-bis (3-amino-4-methylphenyl) propane, 1,3-bis (4-aminophenoxy) propane, 1,3-bis (3-aminophenoxy) propane, 1,4-bis (4-aminophenoxy) butane, 1,4-bis (3-aminophenoxy) Butane, 1,5-bis (4-aminophenoxy) pentane, 1,5-bis (3-aminophenoxy) pentane, 1,6-bis (4-aminophenoxy) hexane, 1,6-bis (3- Aminophenoxy) hexane, 1,7-bis (4-aminophenoxy) heptane, 1,7- (3-aminophenoxy) heptane, 1,8-bis (4-aminophenoxy) octane, 8-bis (3-aminophenoxy) octane, 1,9-bis (4-aminophenoxy) nonane, 1,9-bis (3-aminophenoxy) nonane, 1,10- (4-aminophenoxy) decane, , 10- (3-aminophenoxy) decane, 1,11- (4-aminophenoxy) undecane, 1,11- (3-aminophenoxy) undecane, 1,12- (4-aminophenoxy) dodecane, 1,12 -(3-Aminophenoxy) dodecane. Bis (4-aminocyclohexyl) methane, bis (4-amino-3-methylcyclohexyl) methane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane and the like.

Further, examples of the diamine side chain include diamine compounds having an alkyl group, a fluorine-containing alkyl group, an aromatic ring, an aliphatic ring, a heterocyclic ring, and a cyclic substituent composed thereof. Specific examples of the diamine compound include diamine compounds represented by the following formulas [DA1] to [DA26].

In the formulas [DA1] to [DA5], R ¹ is an alkyl group having 1 to 22 carbon atoms or a fluorine-containing alkyl group.

In the formulas [DA6] to [DA9], R ² represents —COO—, —OCO—, —CONH—, —NHCO—, —CH ₂ —, —O—, —CO—, or —NH—. , R ³ represents an alkyl group having 1 to 22 carbon atoms or a fluorine-containing alkyl group.

In Formula [DA10] and Formula [DA11], R ⁴ represents —O—, —OCH ₂ —, —CH ₂ O—, —COOCH ₂ —, or —CH ₂ OCO—, and R ⁵ represents 1 carbon atom. These are an alkyl group, alkoxy group, fluorine-containing alkyl group or fluorine-containing alkoxy group having 22 or less.

In the formulas [DA12] to [DA14], R ⁶ represents —COO—, —OCO—, —CONH—, —NHCO—, —COOCH ₂ —, —CH ₂ OCO—, —CH ₂ O—, —OCH. ₂ — or —CH ₂ —, wherein R ⁷ is an alkyl group having 1 to 22 carbon atoms, an alkoxy group, a fluorine-containing alkyl group, or a fluorine-containing alkoxy group.

In Formula [DA15] and Formula [DA16], R ⁸ represents —COO—, —OCO—, —CONH—, —NHCO—, —COOCH ₂ —, —CH ₂ OCO—, —CH ₂ O—, —OCH. ₂ —, —CH ₂ —, —O—, or —NH—, wherein R ⁹ is a fluorine group, a cyano group, a trifluoromethane group, a nitro group, an azo group, a formyl group, an acetyl group, an acetoxy group, or a hydroxyl group. is there.

In addition, diaminosiloxane represented by the following formula [DA27] and the like are also included.

(In the formula [DA27], m is an integer of 1 to 10.)
Other diamine compounds may be used alone or in combination of two or more depending on the liquid crystal alignment properties, voltage holding characteristics, accumulated charge, and the like when the liquid crystal alignment film is formed.

<Tetracarboxylic dianhydride>
The tetracarboxylic dianhydride reacted with the diamine component to obtain the polyamic acid of the present invention is not particularly limited. The preferable specific example is given below.
Pyromellitic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic Acid dianhydride, 2,3,6,7-anthracene tetracarboxylic dianhydride, 1,2,5,6-anthracene tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic Acid dianhydride, 2,3,3 ′, 4-biphenyltetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride Bis (3,4-dicarboxyphenyl) sulfone, bis (3,4-dicarboxyphenyl) methane, 2,2-bis (3,4-dicarboxyphenyl) propane, 1,1,1,3 3,3- Oxafluoro-2,2-bis (3,4-dicarboxyphenyl) propane, bis (3,4-dicarboxyphenyl) dimethylsilane, bis (3,4-dicarboxyphenyl) diphenylsilane, 2,3,4, 5-pyridinetetracarboxylic dianhydride, 2,6-bis (3,4-dicarboxyphenyl) pyridine, 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic dianhydride, 3,4,9 , 10-perylenetetracarboxylic dianhydride, 1,3-diphenyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, oxydiphthaltetracarboxylic dianhydride, 1,2,3,4 -Cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cycloheptanetetracarboxylic dianhydride, 2,3,4,5-tetrahydrofurantetra Carboxylic dianhydride, 3,4-dicarboxy-1-cyclohexylsuccinic dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 3,4-dicarboxy-1,2,3 4-tetrahydro-1-naphthalene succinic dianhydride, bicyclo [3,3,0] octane-2,4,6,8-tetracarboxylic dianhydride, bicyclo [4,3,0] nonane-2, 4,7,9- Tracarboxylic dianhydride, bicyclo [4,4,0] decane-2,4,7,9-tetracarboxylic dianhydride, bicyclo [4,4,0] decane-2,4,8,10- Tetracarboxylic dianhydride, tricyclo [6.3.0.0 <2,6>] undecane-3,5,9,11-tetracarboxylic dianhydride, 1,2,3,4-butanetetracarboxylic Acid dianhydride, 4- (2,5-dioxotetrahydrofuran-3-yl) -1,2,3,4-tetrahydraphthalene-1,2-dicarboxylic dianhydride, bicyclo [2,2,2 ] Oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 5- (2,5-dioxotetrahydrofuryl) -3-methyl-3-cyclohexane-1,2-dicarboxylic acid Acid dianhydride, tetracyclo [6,2,1,1,0,2,7] Dodeca-4,5,9,10-tetracarboxylic dianhydride, 3,5,6-tricarboxynorbornane-2: 3,5: 6 dicarboxylic dianhydride, 1,2,4,5-cyclohexanetetra Examples thereof include carboxylic dianhydrides.

The tetracarboxylic dianhydride can be used alone or in combination of two or more depending on the liquid crystal alignment properties, voltage holding characteristics, accumulated charge, and the like when the liquid crystal alignment film is formed.
In obtaining the polyamic acid of the present invention by reaction of tetracarboxylic dianhydride and a diamine component, a known synthesis method can be used. In general, tetracarboxylic dianhydride and a diamine component are reacted in an organic solvent. The reaction between the tetracarboxylic dianhydride and the diamine component is advantageous in that it proceeds relatively easily in an organic solvent and no by-product is generated.
The organic solvent used for the reaction between the tetracarboxylic dianhydride and the diamine component is not particularly limited as long as the produced polyamic acid dissolves. Specific examples are given below.

N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, dimethylsulfoxide, tetramethylurea, pyridine, dimethylsulfone, hexamethylsulfoxide, γ-butyrolactone, isopropyl alcohol, Methoxymethylpentanol, dipentene, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethylene Glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether , Propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol-tert-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether , Dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether , 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, dioxane, n-hexane, n -Pentane, n-octane, diethyl ether, cyclohexanone, ethylene carbonate, propylene carbonate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether, methyl pyruvate, ethyl pyruvate, Methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid Propyl 3-methoxypropionate, butyl 3-methoxypropionate, diglyme, 4-hydroxy-4-methyl-2-pentanone and the like. These may be used alone or in combination. Further, even a solvent that does not dissolve the polyamic acid may be used by mixing with the above solvent as long as the produced polyamic acid does not precipitate.

In addition, since water in the organic solvent inhibits the polymerization reaction and further causes hydrolysis of the produced polyamic acid, it is preferable to use a dehydrated and dried organic solvent as much as possible.
When the tetracarboxylic dianhydride and the diamine component are reacted in an organic solvent, the solution in which the diamine component is dispersed or dissolved in the organic solvent is stirred, and the tetracarboxylic dianhydride is used as it is or in an organic solvent. A method of adding by dispersing or dissolving, a method of adding a diamine component to a solution in which tetracarboxylic dianhydride is dispersed or dissolved in an organic solvent, and alternately adding a tetracarboxylic dianhydride and a diamine component. Any of these methods may be used. In addition, when the tetracarboxylic dianhydride or diamine component consists of a plurality of types of compounds, they may be reacted in a premixed state, may be individually reacted sequentially, or may be further reacted individually. May be mixed to form a high molecular weight product.

The polymerization temperature at that time can be selected from -20 ° C. to 150 ° C., but is preferably in the range of −5 ° C. to 100 ° C. The reaction can be carried out at any concentration, but if the concentration is too low, it is difficult to obtain a high molecular weight polymer, and if the concentration is too high, the viscosity of the reaction solution becomes too high and uniform stirring is difficult. Therefore, the total concentration of the tetracarboxylic dianhydride and the diamine component in the reaction solution is preferably 1 to 50% by mass, more preferably 5 to 30% by mass. The initial stage of the reaction is carried out at a high concentration, and then an organic solvent can be added.

In the polyamic acid polymerization reaction, the ratio of the total number of moles of tetracarboxylic dianhydride to the total number of moles of the diamine component is preferably 0.8 to 1.2. Similar to the normal polymerization reaction, the molecular weight of the polyamic acid produced increases as the molar ratio approaches 1.0.
The polyimide of the present invention is a polyimide obtained by dehydrating and ring-closing the above polyamic acid, and is useful as a polymer for obtaining a liquid crystal alignment film.
In the polyimide of the present invention, the dehydration cyclization rate (imidation rate) of the amic acid group is not necessarily 100%, and can be arbitrarily adjusted according to the application and purpose.
Examples of the method for imidizing the polyamic acid include thermal imidization in which the polyamic acid solution is heated as it is, and catalytic imidization in which a catalyst is added to the polyamic acid solution.
The temperature at which the polyamic acid is thermally imidized in the solution is 100 ° C. to 400 ° C., preferably 120 ° C. to 250 ° C., and it is preferable to carry out while removing water generated by the imidation reaction from the system.

The catalytic imidation of the polyamic acid can be carried out by adding a basic catalyst and an acid anhydride to the polyamic acid solution and stirring at -20 ° C to 250 ° C, preferably 0 ° C to 180 ° C. The amount of the basic catalyst is 0.5 to 30 mol times, preferably 2 to 20 mol times of the amic acid group, and the amount of the acid anhydride is 1 to 50 mol times, preferably 3 to 30 mol of the amido acid group. Is double. Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine, and the like. Among them, pyridine is preferable because it has an appropriate basicity for proceeding with the reaction. Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, pyromellitic anhydride, and the like. Among them, use of acetic anhydride is preferable because purification after completion of the reaction is easy. The imidization rate by catalytic imidation can be controlled by adjusting the amount of catalyst, reaction temperature, and reaction time.

When the produced polyamic acid or polyimide is recovered from the polyamic acid or polyimide reaction solution, the reaction solution may be poured into a poor solvent and precipitated. Examples of the poor solvent used for precipitation include methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, and water. The polymer precipitated in a poor solvent and collected by filtration can be dried by normal temperature or reduced pressure at room temperature or by heating. In addition, when the polymer collected by precipitation is redissolved in an organic solvent and reprecipitation and collection is repeated 2 to 10 times, impurities in the polymer can be reduced. Examples of the poor solvent at this time include alcohols, ketones, hydrocarbons and the like, and it is preferable to use three or more kinds of poor solvents selected from these because purification efficiency is further improved.

The molecular weight of the polyamic acid and the polyimide contained in the liquid crystal aligning agent of the present invention is determined by considering the strength of the coating film obtained therefrom, the workability when forming the coating film, and the uniformity of the coating film. The weight average molecular weight measured by the Permeation Chromatography method is preferably 5,000 to 1,000,000, more preferably 10,000 to 150,000.

<Liquid crystal aligning agent>
The liquid crystal aligning agent of this invention is a coating liquid for forming a liquid crystal aligning film, and is a solution in which a polymer component for forming a polymer film is dissolved in a solvent. Here, the polymer component includes at least one polymer of the polymer of the present invention described above. In this case, the content of the polymer component is preferably 1% by mass to 20% by mass, more preferably 3% by mass to 15% by mass, and particularly preferably 3% by mass to 10% by mass in the liquid crystal aligning agent.

In the present invention, all of the above polymer components may be the polymer of the present invention, and may contain other polymers as long as the effects of the present invention are not impaired. When the polymer component contains another polymer, the content thereof is preferably 0.05 to 4 parts by mass, more preferably 0.1 to 3 parts by mass with respect to 1 part by mass of the polymer of the present invention. It is.

Examples of the other polymer include a polyamic acid obtained by using a diamine compound other than the specific diamine compound as a diamine component to be reacted with a tetracarboxylic dianhydride component, or a polyimide obtained by imidizing the polyamic acid. Is mentioned.
The solvent used in the liquid crystal aligning agent of the present invention is preferably an organic solvent that dissolves the polymer component, and specific examples thereof are given below.
N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 2-pyrrolidone, N-ethylpyrrolidone, N-vinylpyrrolidone, dimethylsulfoxide, tetramethylurea, pyridine, Dimethyl sulfone, hexamethyl sulfoxide, γ-butyrolactone, 1,3-dimethyl-imidazolidinone, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, cyclohexanone, ethylene carbonate, propylene carbonate, diglyme, 4 -Hydroxy-4-methyl-2-pentanone and the like. These may be used alone or in combination.

The liquid crystal aligning agent of this invention may contain components other than the above. Examples thereof include solvents and compounds that improve the film thickness uniformity and surface smoothness when a liquid crystal alignment treatment agent is applied, and compounds that improve the adhesion between the liquid crystal alignment film and the substrate.
Examples of the solvent that improves the uniformity of the film thickness and the surface smoothness include poor solvents that have low solubility in the polymer component in the liquid crystal aligning agent. Specific examples of the poor solvent include the following.

For example, isopropyl alcohol, methoxymethylpentanol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethyl carbitol acetate, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoacetate Isopropyl ether, ethylene glycol monobutyl ether, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol-tert-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoacetate, diethylene glycol dimethyl ether, dip Pyrene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3 -Methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl Ether, 1-hexanol, n-hexane, n-pentane, n-octa , Diethyl ether, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate Ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-butoxy-2-propanol, 1-phenoxy-2-propanol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol Low 1-monoethyl ether-2-acetate, dipropylene glycol, 2- (2-ethoxypropoxy) propanol, lactate methyl ester, lactate ethyl ester, lactate n-propyl ester, lactate n-butyl ester, lactate isoamyl ester Examples include solvents having surface tension.

These poor solvents may be used alone or in combination. When the poor solvent as described above is used, the poor solvent is preferably 5 to 80% by mass, more preferably 20 to 60% by mass, based on the total amount of the solvent contained in the liquid crystal aligning agent.
Examples of the compound that improves the uniformity of the film thickness and the surface smoothness include a fluorine-based surfactant, a silicone-based surfactant, and a nonionic surfactant.

More specifically, for example, F-top EF301, EF303, EF352 (manufactured by Tochem Products), MegaFuck F171, F173, R-30 (manufactured by Dainippon Ink), Florard FC430, FC431 (manufactured by Sumitomo 3M) Asahi Guard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by Asahi Glass Co., Ltd.). The use ratio of these surfactants is preferably 0.01 to 2 parts by mass, more preferably 0.01 to 1 part by mass with respect to 100 parts by mass of the polymer component contained in the liquid crystal aligning agent. is there.

Specific examples of the compound that improves the adhesion between the liquid crystal alignment film and the substrate include the following functional silane-containing compounds and epoxy group-containing compounds.
For example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxy Carbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-tri Toxisilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyltrimethoxy Silane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3-aminopropyl Trimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, poly Lopylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl -2,4-hexanediol, N, N, N ′, N ′,-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ′ , N ′,-tetraglycidyl-4,4′-diaminodiphenylmethane and the like.

When using a compound that improves the adhesion to the substrate, the amount used is preferably 0.1 to 30 parts by mass with respect to 100 parts by mass of the polymer component contained in the liquid crystal aligning agent, More preferably, it is 1 to 20 parts by mass. If the amount used is less than 0.1 parts by mass, the effect of improving the adhesion cannot be expected, and if it exceeds 30 parts by mass, the orientation of the liquid crystal may deteriorate.
In addition to the above, the liquid crystal alignment treatment agent of the present invention is a dielectric or conductive material for the purpose of changing the electrical properties such as the dielectric constant and conductivity of the liquid crystal alignment film as long as the effects of the present invention are not impaired. A substance, and further, a crosslinkable compound for the purpose of increasing the hardness and density of the liquid crystal alignment film may be added.

<Liquid crystal alignment film and liquid crystal display element>
The liquid crystal alignment treatment agent of the present invention can be used as a liquid crystal alignment film without applying an alignment treatment after being applied and baked on a substrate and then subjected to an alignment treatment by rubbing treatment, light irradiation, or the like. In this case, the substrate to be used is not particularly limited as long as it is a highly transparent substrate, and a glass substrate or a plastic substrate such as an acrylic substrate or a polycarbonate substrate can be used. In addition, it is preferable to use a substrate on which an ITO electrode or the like for driving liquid crystal is formed from the viewpoint of simplifying the process. Further, in the reflection type liquid crystal display element, an opaque material such as a silicon wafer can be used as long as the substrate is only on one side, and in this case, a material that reflects light such as aluminum can be used.

The method for applying the liquid crystal alignment treatment agent is not particularly limited, but industrially, methods such as screen printing, offset printing, flexographic printing, and ink jet are generally used. Other coating methods include dip, roll coater, slit coater, spinner and the like, and these may be used depending on the purpose.

Firing after applying the liquid crystal aligning agent on the substrate is performed at 50 ° C. to 300 ° C., preferably 80 ° C. to 250 ° C. by a heating means such as a hot plate, and the solvent is evaporated to form a coating film. Can do. If the thickness of the coating film formed after baking is too thick, it is disadvantageous in terms of power consumption of the liquid crystal display element, and if it is too thin, the reliability of the liquid crystal display element may be lowered. The thickness is preferably 10 to 100 nm. When the liquid crystal is horizontally or tilted, the fired coating film is treated by rubbing or irradiation with polarized ultraviolet rays.
The liquid crystal display element of the present invention is a liquid crystal display element obtained by obtaining a substrate with a liquid crystal alignment film from the liquid crystal aligning agent of the present invention by the method described above, and then preparing a liquid crystal cell by a known method.

As an example of liquid crystal cell production, prepare a pair of substrates on which a liquid crystal alignment film is formed, spread a spacer on the liquid crystal alignment film of one substrate, and make the liquid crystal alignment film surface inside, Examples include a method in which the other substrate is attached and liquid crystal is injected under reduced pressure, or a method in which the substrate is attached to the surface after the liquid crystal is dropped on the liquid crystal alignment film surface on which spacers are dispersed, and the like is sealed. The thickness of the spacer at this time is preferably 1 to 30 μm, more preferably 2 to 10 μm.
As described above, the liquid crystal display device manufactured using the liquid crystal aligning agent of the present invention has excellent reliability and can be suitably used for a large-screen, high-definition liquid crystal television.

EXAMPLES The present invention will be described in more detail below with reference to examples and comparative examples, but the interpretation of the present invention is not limited to these examples.
[Synthesis of diamine compound]
<Example 1>
Synthesis of diamine compound (4)

A solution of compound (2) (57.00 g, 455 mmol) and triethylamine (46.08 g, 455 mmol) in tetrahydrofuran (1000 g) was cooled to 10 ° C. or lower, and compound (1) (100.00 g, 434 mmol) in tetrahydrofuran (500 g) was cooled. ) The solution was added dropwise taking care of the exotherm. After completion of the dropwise addition, the reaction temperature was raised to 23 ° C. and further reaction was performed. After confirming the completion of the reaction by HPLC (high performance liquid chromatograph), the reaction solution was poured into distilled water (9 L), the precipitated solid was filtered, washed with water, dispersed and washed with 2-propanol (200 g), Compound (3) was obtained (yield: 120.6 g, yield: 89%).
¹ H-NMR ( ¹ H nuclear magnetic resonance spectroscopy) (400 MHz, DMSO-d6, δ (ppm)): 9.21 (1H, t), 9.05 (2H, d), 8.97 (1H, t), 7.66 (1H, s), 7.22 (1H, s), 6.90 (1H, s), 4.05 (2H, t), 3.31 (2H, q), 2.01 (2H, tt).

Next, a mixture of compound (3) (100.00 g, 313 mmol), 5% palladium carbon (hydrous type, 10.00 g, 10 wt%) and N, N-dimethylformamide (2000 g) was added in the presence of hydrogen. Stir at 23 ° C. After completion of the reaction, the atmosphere was replaced with nitrogen, activated carbon (10.00 g) was added, and the mixture was stirred at 23 ° C. for 1 hour. Thereafter, the catalyst and activated carbon were removed by filtration, and the filtrate was distilled off to obtain crude crystals. 2-Propanol (300 g) was added to the crude crystals, and the mixture was stirred at 23 ° C. for 30 minutes. Filtration and drying were performed to obtain a diamine compound (4) (yield: 76.3 g, yield: 94%).
¹ H-NMR (400 MHz, DMSO-d6, δ (ppm)): 8.05 (1H, t), 7.62 (1H, t),
7.16 (1H, t), 6.85 (1H, t), 6.16 (2H, d), 5.89 (1H, t), 4.82 (4H, broad),
3.94 (2H, t), 3.43 (2H, q), 1.85 (2H, tt).

<Example 2>
Synthesis of diamine compound (7)

A solution of compound (5) (24.00 g, 195 mmol) and triethylamine (19.72 g, 195 mmol) in tetrahydrofuran (500 g) was cooled to 10 ° C. or lower, and compound (1) (42.80 g, 186 mmol) in tetrahydrofuran (142 g) was cooled. ) The solution was added dropwise taking care of the exotherm. After completion of the dropwise addition, the reaction temperature was raised to 23 ° C. and further reaction was performed. After confirming the completion of the reaction by HPLC, the reaction solution was poured into distilled water (3.9 L), and the precipitated solid was filtered, washed with water, dispersed and washed with 2-propanol (240 g), and compound (6) (Yield: 51.3 g, yield: 87%).
¹ H-NMR (400 MHz, DMSO-d6, δ (ppm)): 9.87 (1H, broad), 9.10 (2H, d),
8.97 (1H, t), 8.57 (1H, d), 8.50 (1H, t), 4.65 (2H, s), 2.84 (3H, s).

Next, a mixture of compound (6) (45.00 g, 142 mmol), 5% palladium carbon (hydrated product, 4.5 g, 10 wt%), and 1,4-dioxane (675 g) / DMF (200 g) was added in the presence of hydrogen. Under stirring at 70 ° C. After completion of the reaction, the atmosphere was replaced with nitrogen, activated carbon (4.5 g) was added, and the mixture was stirred at 70 ° C. for 1 hour. Thereafter, the catalyst and activated carbon were removed by filtration, and the filtrate was distilled off to obtain crude crystals. The obtained crude product was dispersed and washed with 2-propanol (100 g) to obtain a diamine compound (7) (yield: 33.7 g, yield: 92%).
¹ H-NMR (400 MHz, DMSO-d6, δ ppm): 8.60 (1H, t), 8.42 (1H, m),
8.38 (1H, d), 6.22 (2H, d), 5.92 (1H, t), 4.84 (4H, s), 4.43 (2H, d), 2.43 (3H, s).

<Example 3>
Synthesis of diamine compound (10)

A solution of compound (8) (24.00 g, 146 mmol) and triethylamine (14.79 g, 146 mmol) in tetrahydrofuran (332 g) was cooled to 10 ° C. or lower, and compound (1) (32.10 g, 139 mmol) in tetrahydrofuran (100 g). ) The solution was added dropwise taking care of the exotherm. After completion of the dropwise addition, the reaction temperature was raised to 23 ° C. and further reaction was performed. After confirming the completion of the reaction by HPLC, the reaction solution was poured into distilled water (3.9 L), the precipitated solid was filtered, washed with water, dispersed and washed with 2-propanol (200 g), and compound (9) (Yield: 47.6 g, yield: 95%).
¹ H-NMR (400 MHz, DMSO-d6, δ (ppm)): 8.88 (1H, t), 8.70 (2H, d), 8.40 (2H, t), 6.68 (1H, t), 3.9 (2H, broad ), 3.75 (4H, broad), 3.42 (2H, broad).

Next, a mixture of compound (9) (40.00 g, 112 mmol), 5% palladium carbon (hydrated product, 4.0 g, 10 wt%), and DMF (800 g) was stirred at 70 ° C. in the presence of hydrogen. . After completion of the reaction, the catalyst was filtered through celite, and then the solvent was distilled off with an evaporator to obtain a crude product. The obtained crude product was dispersed and washed with 2-propanol (12 g) to obtain a diamine compound (10) (amount obtained: 1.7 g, yield: 68%).
¹ H-NMR (400 MHz, DMSO-d6, δ (ppm)): 8.35 (2H, d), 6.63 (1H, t), 5.82 (1H, t), 5.75 (2H, d), 4.86 (4H, s ), 3.70 (4H, broad), 3.49 (4H, broad).

<Synthesis Example 1>
Synthesis of diamine compound (13)

A solution of compound (11) (15.22 g, 142 mmol) and triethylamine (15.09 g, 149 mmol) in tetrahydrofuran (150 g) was cooled to 10 ° C. or lower, and compound (1) (31.1 g, 135 mmol) in tetrahydrofuran (50 g) ) The solution was added dropwise taking care of the exotherm. After completion of the dropwise addition, the reaction temperature was raised to 23 ° C. and further reaction was performed. After confirming the completion of the reaction by HPLC, the reaction solution was poured into distilled water (1 L), and then the precipitated solid was filtered and washed with water. Thereafter, the solid was dispersed and washed with ethanol (300 g) to obtain a compound (12) (amount: 36.92 g, yield: 90%).
¹ H-NMR (400 MHz, DMSO-d6, δ (ppm)): 9.75 (1H, broad), 9.10 (2H, s),
8.97-8.92 (1H, m), 7.40-7.22 (5H, m), 4.59-4.52 (2H, m).

Next, a mixture of compound (12) (36.00 g, 119 mmol), 5% palladium carbon (hydrous type, 3.6 g, 10 wt%), and 1,4-dioxane (300 g) was added in the presence of hydrogen in the presence of 60 Stir at ° C. After completion of the reaction, the catalyst was filtered through celite, and then the solvent was distilled off with an evaporator to obtain a crude product. The obtained crude product was recrystallized from methanol (200 g) to obtain a diamine compound (13) (amount: 21.5 g, yield: 72%).
¹ H-NMR (400 MHz, DMSO-d6, δ (ppm)): 8.55 (1H, broad), 7.34-7.17 (5H, m), 6.28 (2H, s), 6.98-6.94 (1H, m), 4.85 -4.74 (4H, broad), 4.42-4.35 (2H, m).

<Synthesis Example 2>
Synthesis of diamine compound (16)

A solution of compound (14) (23.45 g, 190 mmol) and triethylamine (19.23 g, 277 mmol) in tetrahydrofuran (230 g) was cooled to 10 ° C. or lower, and compound (1) (41.68 g, 180 mmol) in tetrahydrofuran (110 g) was cooled. ) The solution was added dropwise taking care of the exotherm. After completion of the dropwise addition, the reaction temperature was raised to 23 ° C. and further reaction was performed. After confirming the completion of the reaction by HPLC (high performance liquid chromatograph), the reaction solution was poured into distilled water (1.5 L), and then the precipitated solid was filtered and washed with water. Thereafter, the solid was dispersed and washed with ethanol (380 g) to obtain compound (15) (amount: 50.82 g, yield: 89%).
¹ H-NMR (400 MHz, DMSO-d6, δ (ppm)): 9.76 (1H, t), 9.09-9.02 (2H, m),
8.99-8.93 (1H, m), 8.50 (1H, broad), 7.64-7.60 (1H, m), 7.36-7.32 (1H, m), 7.20-7.14 (1H, m), 4.57 (2H, s), 3.35 (2H, s).

Next, a mixture of compound (15) (48.00 g, 151 mmol), 5% palladium carbon (hydrous type, 4.8 g, 10 wt%), and 1,4-dioxane (490 g) was added in the presence of hydrogen in the presence of 60 Stir at ° C. After completion of the reaction, the catalyst was filtered through celite, and then the solvent was distilled off with an evaporator to obtain a crude product. The obtained crude product was dispersed and washed with ethanol (300 g) to obtain a diamine compound (16) (amount obtained: 27.20 g, yield: 70%).
¹ H-NMR (400 MHz, DMSO-d6, δ (ppm)): 8.64 (1H, t), 8.50 (1H, d),
8.44 (1H, d), 7.67 (1H, d), 7.34 (1H, q), 6.23 (2H, d), 5.94 (1H, s), 4.87 (4H, s), 4.39 (2H, d).

[Synthesis of polyamic acid and polyimide]
Abbreviations of compounds such as tetracarboxylic dianhydride used are shown below.
(Tetracarboxylic dianhydride)
CBDA: 1,2,3,4-cyclobutanetetracarboxylic dianhydride BODA: bicyclo [3,3,0] octane-2,4,6,8-tetracarboxylic dianhydride

(Diamine compound)
DBA: 3,5-diaminobenzoic acid p-PDA: p-phenylenediamine AP18 :: 1,3-diamino-4-octadecyloxybenzene PCH7DAB: 1,3-diamino-4- [4- (trans-4-n -Heptylcyclohexyl) phenoxy] benzene

(Organic solvent)
NMP: N-methyl-2-pyrrolidone BCS: Butyl cellosolve

<Measurement of molecular weight of polyimide>
The molecular weight of polyimide in the synthesis example was measured as follows using a normal temperature gel permeation chromatography (GPC) apparatus (GPC-101) manufactured by Showa Denko KK and a column (KD-803, KD-805) manufactured by Shodex. .
Column temperature: 50 ° C
Eluent: N, N′-dimethylformamide (as additives, lithium bromide-hydrate (LiBr · H ₂ O) is 30 mmol / L, phosphoric acid / anhydrous crystal (o-phosphoric acid) is 30 mmol / L, Tetrahydrofuran (THF) 10ml / L)
Flow rate: 1.0 ml / min Standard sample for preparing a calibration curve: TSK standard polyethylene oxide (molecular weight: about 900,000, 150,000, 100,000, 30,000) manufactured by Tosoh Corporation and polyethylene glycol (manufactured by Polymer Laboratories) Molecular weight about 12,000, 4,000, 1,000).

<Measurement of imidization ratio>
The imidation ratio of polyimide in the synthesis example was measured as follows.
Add 20 mg of polyimide powder to an NMR sample tube (NMR sampling tube standard φ5 manufactured by Kusano Kagaku Co., Ltd.) and add 0.53 ml of deuterated dimethyl sulfoxide (DMSO-d6, 0.05% TMS (tetramethylsilane) mixture). The solution was completely dissolved by applying ultrasonic waves. This solution was measured for proton NMR at 500 MHz with an NMR measuring instrument (JNW-ECA500) manufactured by JEOL Datum. The imidation rate is determined based on protons derived from structures that do not change before and after imidation as reference protons, and the peak integrated value of these protons and proton peaks derived from NH groups of amic acid appearing in the vicinity of 9.5 to 10.0 ppm. It calculated | required by the following formula | equation using the integrated value.
Imidization rate (%) = (1−α · x / y) × 100
In the above formula, x is a proton peak integrated value derived from NH group of amic acid, y is a peak integrated value of reference proton, α is one NH group proton of amic acid in the case of polyamic acid (imidation rate is 0%) Is the number ratio of the reference proton to.

<Example 4>
BODA (3.24 g, 13.0 mmol), p-PDA (0.65 g, 6.01 mmol), PCH7DAB (3.30 g, 8.67 mmol), and the diamine compound (4) obtained in Example 1 (0) .68 g, 2.62 mmol) were mixed in NMP (14.5 g) and reacted at 80 ° C. for 5 hours, and then CBDA (0.85 g, 4.34 mmol) and NMP (11.9 g) were added. The polyamic acid solution (A) (concentration: 24.8% by mass) was obtained by reacting at 6 ° C. for 6 hours. The number average molecular weight of this polyamic acid was 22,800, and the weight average molecular weight was 53,900.

<Example 5>
NMP was added to the polyamic acid solution (A) (20.0 g) obtained in Example 4 to dilute the polyamic acid concentration to 6% by mass, and then acetic anhydride (2.65 g) and pyridine ( 2.07 g) was added and reacted at 80 ° C. for 2 hours. This reaction solution was put into methanol (350 ml), and the resulting precipitate was separated by filtration. This deposit was wash | cleaned with methanol, and it dried under reduced pressure at 100 degreeC, and obtained the polyimide powder (B). The imidation ratio of this polyimide was 40%, the number average molecular weight was 18,800, and the weight average molecular weight was 49,500.

<Example 6>
BODA (3.25 g, 13.0 mmol), DBA (0.52 g, 3.42 mmol), PCH7DAB (3.30 g, 8.67 mmol), and the diamine compound (4) obtained in Example 1 (1.36 g) , 5.24 mmol) in NMP (15.5 g) and reacted at 80 ° C. for 5 hours, then CBDA (0.85 g, 4.34 mmol) and NMP (12.7 g) were added, and Reaction was performed for 6 hours to obtain a polyamic acid solution (C) (concentration: 24.8% by mass). The number average molecular weight of this polyamic acid was 24,100, and the weight average molecular weight was 55,500.

<Example 7>
After adding NMP to the polyamic acid solution (C) (20.1 g) obtained in Example 6 and diluting the polyamic acid concentration to 6% by mass, acetic anhydride (2.66 g) and pyridine ( 2.07 g) was added and reacted at 80 ° C. for 2 hours. This reaction solution was put into methanol (350 ml), and the resulting precipitate was separated by filtration. This deposit was wash | cleaned with methanol, and it dried under reduced pressure at 100 degreeC, and obtained the polyimide powder (D). The imidation ratio of this polyimide was 40%, the number average molecular weight was 19,900, and the weight average molecular weight was 51,500.

<Example 8>
BODA (3.15 g, 12.6 mmol), p-PDA (1.01 g, 9.34 mmol), AP18 (1.25 g, 3.32 mmol), and the diamine compound (7) obtained in Example 2 (1) .10 g, 4.28 mmol) were mixed in NMP (8.35 g) and reacted at 80 ° C. for 5 hours, and then CBDA (0.85 g, 4.34 mmol) and NMP (6.83 g) were added. The polyamic acid solution was obtained by reacting at 6 ° C. for 6 hours. The number average molecular weight of this polyamic acid was 21,500, and the weight average molecular weight was 52,400.
After adding NMP to the obtained polyamic acid solution (20.0 g) and diluting the polyamic acid concentration to 6% by mass, acetic anhydride (2.65 g) and pyridine (2.07 g) were added as imidization catalysts. And reacted at 80 ° C. for 2 hours. This reaction solution was put into methanol (350 ml), and the resulting precipitate was separated by filtration. This deposit was wash | cleaned with methanol, and it dried under reduced pressure at 100 degreeC, and obtained the polyimide powder (E). The imidation ratio of this polyimide was 40%, the number average molecular weight was 18,100, and the weight average molecular weight was 48,700.

<Example 9>
BODA (3.22 g, 12.9 mmol), DBA (0.79 g, 5.19 mmol), PCH7DAB (3.22 g, 8.46 mmol), and the diamine compound (7) obtained in Example 2 (0.92 g) , 3.58 mmol) in NMP (13.5 g) and reacted at 80 ° C. for 5 hours, then CBDA (0.85 g, 4.34 mmol) and NMP (11.0 g) were added, and Reaction was performed for 6 hours to obtain a polyamic acid solution. The number average molecular weight of this polyamic acid was 23,700, and the weight average molecular weight was 54,000.
After adding NMP to the obtained polyamic acid solution (20.1 g) and diluting the polyamic acid concentration to 6% by mass, acetic anhydride (2.65 g) and pyridine (2.07 g) were added as imidization catalysts. And reacted at 80 ° C. for 2 hours. This reaction solution was put into methanol (350 ml), and the resulting precipitate was separated by filtration. This deposit was wash | cleaned with methanol, and it dried under reduced pressure at 100 degreeC, and obtained the polyimide powder (F). The imidation ratio of this polyimide was 40%, the number average molecular weight was 19,900, and the weight average molecular weight was 49,800.

<Example 10>
BODA (2.97 g, 11.9 mmol), p-PDA (0.70 g, 6.47 mmol), PCH7DAB (3.06 g, 8.04 mmol), and the diamine compound (10) obtained in Example 3 (0 .51 g, 1.71 mmol) were mixed in NMP (12.6 g) and reacted at 80 ° C. for 5 hours, and then CBDA (0.85 g, 4.34 mmol) and NMP (10.3 g) were added. The reaction was carried out at 6 ° C. for 6 hours to obtain a polyamic acid solution (G) (concentration: 26.1% by mass). The number average molecular weight of this polyamic acid was 21,200, and the weight average molecular weight was 52,100.

<Example 11>
After adding NMP to the polyamic acid solution (G) (20.0 g) obtained in Example 10 and diluting the polyamic acid concentration to 6% by mass, acetic anhydride (2.67 g) and pyridine ( 2.05 g) was added and reacted at 80 ° C. for 2 hours. This reaction solution was poured into methanol (360 ml), and the resulting precipitate was filtered off. This deposit was wash | cleaned with methanol, and it dried under reduced pressure at 100 degreeC, and obtained the polyimide powder (H). The imidation ratio of this polyimide was 40%, the number average molecular weight was 18,100, and the weight average molecular weight was 48,500.

<Synthesis Example 3>
BODA (3.22 g, 12.9 mmol), p-PDA (0.65 g, 6.00 mmol), PCH7DAB (3.26 g, 8.57 mmol), and the diamine compound (13) (0) obtained in Synthesis Example 1 (0 .62 g, 2.56 mmol) was mixed in NMP (15.2 g) and reacted at 80 ° C. for 5 hours, and then CBDA (0.84 g, 4.28 mmol) and NMP (11.1 g) were added. The reaction was carried out at 6 ° C. for 6 hours to obtain a polyamic acid solution (I) (concentration: 24.6% by mass). The number average molecular weight of this polyamic acid was 22,100, and the weight average molecular weight was 53,200.

<Synthesis Example 4>
After adding NMP to the polyamic acid solution (I) (20.1 g) obtained in Synthesis Example 3 and diluting the polyamic acid concentration to 6% by mass, acetic anhydride (2.68 g) and pyridine ( 2.04 g) was added and reacted at 80 ° C. for 2 hours. This reaction solution was put into methanol (350 ml), and the resulting precipitate was separated by filtration. This deposit was wash | cleaned with methanol, and it dried under reduced pressure at 100 degreeC, and obtained the polyimide powder (J). The imidation ratio of this polyimide was 41%, the number average molecular weight was 18,400, and the weight average molecular weight was 49,100.

<Synthesis Example 5>
BODA (3.29 g, 13.2 mmol), p-PDA (0.67 g, 6.14 mmol), PCH7DAB (3.34 g, 8.77 mmol), and the diamine compound (16) obtained in Synthesis Example 2 (0 .68 g, 2.79 mmol) were mixed in NMP (15.0 g) and reacted at 80 ° C. for 5 hours, and then CBDA (0.86 g, 4.39 mmol) and NMP (11.5 g) were added. The reaction was carried out at 0 ° C. for 6 hours to obtain a polyamic acid solution (K) (concentration: 25.0% by mass). The number average molecular weight of this polyamic acid was 22,600, and the weight average molecular weight was 54,900.

<Synthesis Example 6>
After adding NMP to the polyamic acid solution (K) (20.0 g) obtained in Synthesis Example 5 and diluting the polyamic acid concentration to 6% by mass, acetic anhydride (2.65 g) and pyridine ( 2.08 g) was added and reacted at 80 ° C. for 2 hours. This reaction solution was poured into methanol (320 ml), and the resulting precipitate was filtered off. This deposit was wash | cleaned with methanol, and it dried under reduced pressure at 100 degreeC, and obtained the polyimide powder (L). The imidation ratio of this polyimide was 40%, the number average molecular weight was 18,900, and the weight average molecular weight was 49,200.

Tables 3 and 4 collectively show reaction conditions (moles of each component) and imidation ratios of Examples 4 to 11 and Synthesis Examples 3 to 6 (synthesis of polyamic acid and polyimide).

[Preparation and evaluation of liquid crystal aligning agent]

<Example 12>
NMP (10.2 g) and BCS (20.0 g) were added to the polyamic acid solution [A] (10.0 g) obtained in Example 4, and the mixture was stirred at 25 ° C. for 2 hours, thereby liquid crystal alignment treatment. Agent [1] was obtained. Abnormalities such as turbidity and precipitation were not observed in this liquid crystal alignment treatment agent, and it was confirmed that the polymer component was uniformly dissolved.
[Production of liquid crystal cell]
The liquid crystal alignment treatment agent [1] obtained above is spin-coated on the ITO surface of the substrate with 3 cm × 4 cm (vertical × horizontal) ITO electrodes, and baked in a hot air circulation oven at 80 ° C. for 5 minutes and 210 ° C. for 1 hour. A polyimide coating film having a thickness of 100 nm was prepared.

This substrate with a liquid crystal alignment film is subjected to a rubbing treatment with a roll diameter 120 mm, a rayon cloth rubbing device under the conditions of a rotation speed of 300 rpm, a roll traveling speed of 20 mm / sec, and an indentation amount of 0.3 mm. Got.
Two substrates with this liquid crystal alignment film were prepared, and a 6 μm bead spacer was sprayed on the surface of one liquid crystal alignment film, and then a sealant was printed thereon. The other prepared substrate was bonded so that the liquid crystal alignment film surface was on the inside and the rubbing direction was reversed, and then the sealing agent was cured to produce an empty cell. Liquid crystal MLC-6608 (manufactured by Merck Japan Ltd.) was injected into this empty cell by a reduced pressure injection method to obtain an antiparallel aligned nematic liquid crystal cell.
[Evaluation of voltage holding ratio]
A voltage of 4 V is applied to the liquid crystal cell obtained above at a temperature of 80 ° C. for 60 μs, the voltage after 16.67 ms and 1667 ms is measured, and the voltage holding ratio (%) As calculated. The results are shown in Table 5.
[Evaluation of relaxation of residual charge]
A DC voltage of 10 V was applied to the liquid crystal cell after measuring the voltage holding ratio for 30 minutes and short-circuited for 1 second, and then the potential generated in the liquid crystal cell was measured for 1800 seconds. Then, the residual charge (V) after 50 seconds and after 1000 seconds was measured. For measurement, a 6254 type liquid crystal property evaluation apparatus manufactured by Toyo Technica Co., Ltd. was used. The results are shown in Table 6.
[Evaluation after leaving at high temperature]
After the residual charge measurement, the liquid crystal cell was left in a high-temperature bath set at 100 ° C. for 7 days, and then the voltage holding ratio and the residual charge were measured. The results are shown in Table 5 and Table 6 described later.

With respect to the liquid crystal aligning agents obtained in the following Examples 13 to 19 and Comparative Examples 1 to 4, as in Example 12, liquid crystal cells were prepared using these liquid crystal aligning agents, and each liquid crystal The cell was evaluated. The results are summarized in Table 5 and Table 6.

<Example 13>
NMP (36.3 g) was added to the polyimide powder [B] (5.1 g) obtained in Example 5, and dissolved by stirring at 70 ° C. for 40 hours. NMP (18.1 g) and BCS (25.6 g) were added to this solution, and the mixture was stirred at 25 ° C. for 2 hours to obtain a liquid crystal aligning agent [2]. Abnormalities such as turbidity and precipitation were not observed in this liquid crystal alignment treatment agent, and it was confirmed that the polymer component was uniformly dissolved.

<Example 14>
NMP (10.2 g) and BCS (20.0 g) were added to the polyamic acid solution [C] (10.0 g) obtained in Example 6, and the mixture was stirred at 25 ° C. for 2 hours, thereby liquid crystal alignment treatment. Agent [3] was obtained. Abnormalities such as turbidity and precipitation were not observed in this liquid crystal alignment treatment agent, and it was confirmed that the polymer component was uniformly dissolved.

<Example 15>
NMP (30.3 g) was added to the polyimide powder [D] (5.0 g) obtained in Example 7 and dissolved by stirring at 70 ° C. for 40 hours. NMP (14.8g) and BCS (33.8g) were added to this solution, and it stirred at 25 degreeC for 2 hours, and obtained liquid-crystal aligning agent [4]. Abnormalities such as turbidity and precipitation were not observed in this liquid crystal alignment treatment agent, and it was confirmed that the polymer component was uniformly dissolved.

<Example 16>
NMP (33.0 g) was added to the polyimide powder [E] (5.1 g) obtained in Example 8, and dissolved by stirring at 70 ° C. for 40 hours. NMP (17.1g) and BCS (29.8g) were added to this solution, and the liquid-crystal aligning agent [5] was obtained by stirring at 25 degreeC for 2 hours. Abnormalities such as turbidity and precipitation were not observed in this liquid crystal alignment treatment agent, and it was confirmed that the polymer component was uniformly dissolved.

<Example 17>
NMP (34.5 g) was added to the polyimide powder [F] (5.2 g) obtained in Example 9, and dissolved by stirring at 70 ° C. for 40 hours. NMP (16.5g) and BCS (30.3g) were added to this solution, and the liquid-crystal aligning agent [6] was obtained by stirring at 25 degreeC for 2 hours. Abnormalities such as turbidity and precipitation were not observed in this liquid crystal alignment treatment agent, and it was confirmed that the polymer component was uniformly dissolved.

<Example 18>
NMP (15.6 g) and BCS (17.1 g) were added to the polyamic acid solution [G] (10.0 g) obtained in Example 10, and the mixture was stirred at 25 ° C. for 2 hours, thereby liquid crystal alignment treatment. Agent [7] was obtained. Abnormalities such as turbidity and precipitation were not observed in this liquid crystal alignment treatment agent, and it was confirmed that the polymer component was uniformly dissolved.

<Example 19>
NMP (35.5 g) was added to the polyimide powder [H] (5.0 g) obtained in Example 11, and dissolved by stirring at 70 ° C. for 40 hours. NMP (17.8g) and BCS (25.1g) were added to this solution, and it stirred at 25 degreeC for 2 hours, and obtained liquid-crystal aligning agent [8]. Abnormalities such as turbidity and precipitation were not observed in this liquid crystal alignment treatment agent, and it was confirmed that the polymer component was uniformly dissolved.

<Comparative Example 1>
NMP (18.8 g) and BCS (12.2 g) were added to the polyamic acid solution [I] (10.0 g) obtained in Synthesis Example 3, and the mixture was stirred at 25 ° C. for 2 hours to obtain a liquid crystal alignment treatment. Agent [9] was obtained. Abnormalities such as turbidity and precipitation were not observed in this liquid crystal alignment treatment agent, and it was confirmed that the polymer component was uniformly dissolved.

<Comparative Example 2>
NMP (38.6 g) was added to the polyimide powder [J] (4.7 g) obtained in Synthesis Example 4, and dissolved by stirring at 70 ° C. for 40 hours. NMP (19.4g) and BCS (15.8g) were added to this solution, and the liquid-crystal aligning agent [10] was obtained by stirring at 25 degreeC for 2 hours. Abnormalities such as turbidity and precipitation were not observed in this liquid crystal alignment treatment agent, and it was confirmed that the polymer component was uniformly dissolved.

<Comparative Example 3>
NMP (17.5 g) and BCS (15.3 g) were added to the polyamic acid solution [K] (10.4 g) obtained in Synthesis Example 5, and the mixture was stirred at 25 ° C. for 2 hours, thereby liquid crystal alignment treatment. Agent [11] was obtained. Abnormalities such as turbidity and precipitation were not observed in this liquid crystal alignment treatment agent, and it was confirmed that the polymer component was uniformly dissolved.

<Comparative Example 4>
NMP (34.5 g) was added to the polyimide powder [L] (4.5 g) obtained in Synthesis Example 6 and dissolved by stirring at 70 ° C. for 40 hours. NMP (17.2g) and BCS (18.8g) were added to this solution, and the liquid-crystal aligning agent [12] was obtained by stirring at 25 degreeC for 2 hours. Abnormalities such as turbidity and precipitation were not observed in this liquid crystal alignment treatment agent, and it was confirmed that the polymer component was uniformly dissolved.

The liquid crystal aligning agent containing the diamine compound of the present invention has a high voltage holding ratio when it is formed into a liquid crystal alignment film, and alleviates charges accumulated by direct current voltage even after being exposed to a high temperature for a long time. Can be obtained. Furthermore, a highly reliable liquid crystal display element that can withstand long-term use in a severe use environment can be provided. As a result, it is useful for TN elements, STN elements, TFT liquid crystal elements, and liquid crystal display elements of vertical alignment type and horizontal alignment type (IPS).
The entire contents of the specification, claims, and abstract of Japanese Patent Application No. 2009-170396 filed on July 21, 2009 are incorporated herein as the disclosure of the specification of the present invention. Is.

Claims

A diamine compound of the following formula [1].

(Wherein X 1 represents —CO— or —CONH—, X 2 represents an alkylene group having 1 to 5 carbon atoms, or a non-aromatic heterocyclic ring containing a nitrogen atom, and X 3 represents 1 to 5 carbon atoms) It represents a 5-membered or 6-membered aromatic heterocycle containing two nitrogen atoms, which may be substituted with 5 alkyl groups.
The diamine compound according to claim 1, wherein the aromatic heterocycle is an imidazole ring, a pyrazine ring, or a pyrimidine ring.
The diamine compound according to claim 1 or 2, wherein the non-aromatic heterocyclic ring containing a nitrogen atom is a piperazine ring.
A polyamic acid obtained by reacting the diamine component containing the diamine compound according to any one of claims 1 to 3 with a tetracarboxylic dianhydride component or a polyimide obtained by imidizing the polyamic acid.
The polyamic acid according to claim 4 or a polyimide obtained by imidizing the polyamic acid, wherein the diamine component contains 1 to 80 mol% of the diamine compound according to any one of claims 1 to 3.
The polyamic acid according to claim 4 or a polyimide obtained by imidizing the polyamic acid, wherein the diamine component contains a diamine compound containing a carboxyl group in the molecule.
The diamine component contains 0.01 to 99 mol of a diamine compound having a carboxyl group in the molecule with respect to 1 mol of the diamine compound according to any one of claims 1 to 3. Or a polyimide obtained by imidizing the polyamic acid.
The polyamic acid according to claim 6 or 7, wherein the diamine compound having a carboxyl group in the molecule is a diamine represented by the following formula [2].

(In the formula [2], X 5 is an organic group having an aromatic ring having 6 to 30 carbon atoms, and n is an integer of 1 to 4.)
A liquid crystal aligning agent comprising at least one of the polyamic acid according to any one of claims 4 to 8 and a polyimide obtained by imidizing the polyamic acid, and a solvent.
The liquid crystal aligning agent according to claim 9, wherein 5 to 80% by mass of the solvent is a poor solvent.
A liquid crystal alignment film obtained from the liquid crystal aligning agent according to claim 9 or 10.
A liquid crystal display element having the liquid crystal alignment film according to claim 11.