JP2008216671A - Liquid crystal aligning agent and liquid crystal display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal aligning agent having high aligning property and storage stability. <P>SOLUTION: The liquid crystal aligning agent contains a polyamic acid and/or its imidized polymer obtained by the reaction of a tetracaboxylic acid dianhydride having a tetravalent organic group, a diamine compound having a bivalent organic group, and a monoamine compound having a 1-30C linear, branched or cyclic alkyl group or fluoroalkyl group or having a 4-30C linear, branched or cyclic alkenyl group or fluoroalkenyl group. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a liquid crystal aligning agent and a liquid crystal display element used for forming a liquid crystal alignment film of a liquid crystal display element. More specifically, the present invention relates to a liquid crystal aligning agent and a liquid crystal display element that provide a liquid crystal alignment film having good orientation and good storage stability.

  Currently, as a liquid crystal display element, a liquid crystal alignment film made of polyamic acid, polyimide, or the like is formed on the surface of a substrate on which a transparent conductive film is provided to form a liquid crystal display element substrate. A nematic liquid crystal layer having positive dielectric anisotropy is formed in a cell having a sandwich structure so that the major axis of the liquid crystal molecules is continuously twisted 90 degrees from one substrate to the other. A TN liquid crystal display element having a so-called TN (twisted nematic) liquid crystal cell is known. Further, STN (Super Twisted Nematic) type liquid crystal display elements and vertical alignment type liquid crystal display elements, which have a higher contrast than the TN type liquid crystal display elements and have less viewing angle dependency, have been developed. This STN type liquid crystal display element uses nematic liquid crystal blended with a chiral agent which is an optically active substance as liquid crystal, and the major axis of liquid crystal molecules is continuously twisted over 180 degrees between substrates. The birefringence effect generated by the above is utilized. On the other hand, as described in Non-Patent Document 1 and Patent Document 1, a vertical alignment type liquid crystal display element called an MVA method is proposed in which protrusions are formed on an ITO film to control the alignment direction of liquid crystal. ing. The MVA liquid crystal display element is excellent in terms of manufacturing process, such as excellent viewing angle and contrast, and need not be rubbed in forming the liquid crystal alignment film. As a liquid crystal alignment film suitable for the TN, STN, and MVA methods, performance such as a short afterimage erasing time of the liquid crystal display element is required. The alignment of the liquid crystal in the liquid crystal display element such as the TN, STN, or MVA type display element is usually realized by a liquid crystal alignment film provided with alignment ability of liquid crystal molecules by rubbing treatment. Here, as materials for the liquid crystal alignment film constituting the liquid crystal display element, resins such as polyimide, polyamide, and polyester are conventionally known. In particular, polyimide is used in many liquid crystal display elements because of its excellent heat resistance, affinity with liquid crystals, mechanical strength, and the like.

However, when a liquid crystal display element or the like is produced using a conventionally known polyamic acid or a liquid crystal aligning agent containing an imidized polymer obtained by dehydrating and cyclizing it, the characteristics as a liquid crystal display element are deteriorated due to poor alignment. Has the problem. In addition, there is a problem that the viscosity of the solution changes during storage of the liquid crystal aligning agent solution, resulting in large variations in film thickness during printing.
Japanese Patent Laid-Open No. 11-258605 “Liquid Crystal” Vol. 3 No. 2,117 (1999)

  The present invention has been made in view of the above-mentioned problems, and the object of the present invention is to provide a liquid crystal aligning agent having excellent orientation and excellent storage stability in a polyimide-based liquid crystal alignment film, and It is in providing the used liquid crystal display element.

  Still other objects and advantages of the present invention will become apparent from the following description.

According to the present invention, the above objects and advantages of the present invention are as follows.
Formula (I)

Here, R ₁ represents a tetravalent organic group.
A tetracarboxylic dianhydride represented by the following formula (II):

Here, R ₂ represents a divalent organic group.
And the following formula (III-1), (III-2) or (III-3):

Here, R ₃ , R ₄ and R ₅ are each independently a linear, branched or cyclic alkyl group or fluoroalkyl group having 1 to 30 carbon atoms, or a linear or branched group having 4 to 30 carbon atoms. Or a cyclic alkenyl group or a fluoroalkenyl group, and A is a hydrogen atom or a methyl group.
It is achieved by a liquid crystal aligning agent characterized by containing a polymer obtained by reacting a monoamine compound (hereinafter referred to as “specific monoamine compound”) and / or an imidized polymer thereof.

According to the present invention, the above objects and advantages of the present invention are secondly,
This is achieved by a liquid crystal display device comprising a liquid crystal alignment film obtained from the liquid crystal alignment agent of the present invention.

  Hereinafter, the present invention will be described in detail.

  The liquid crystal aligning agent of this invention is comprised by melt | dissolving the polyamic acid and / or polyimide polymer containing a specific monoamine compound in the organic solvent.

<Specific monoamine compound>
In the above formulas (III-1) to (III-3), the substitution position of the amino group is not particularly limited. Examples include ortho and para positions. Substituents R _{3 to} R ₅ are linear, branched or cyclic alkyl or fluoroalkyl groups having 1 to 30 carbon atoms, or linear, branched or cyclic alkenyl groups or fluoro having 4 to 30 carbon atoms. An alkenyl group, and A is a hydrogen atom or a methyl group;
The fluoroalkyl group and fluoroalkenyl group preferably contain 1 to 15 fluorine atoms.

  Examples of monoamine compounds represented by the above formulas (III-1), (III-2), and (III-3) include 1- (4-aminophenyl) -3-hexylsuccinimide, 1- (4- Aminophenyl) -3- (2-ethylhexyl) succinimide, 1- (4-aminophenyl) -3-octylsuccinimide, 1- (4-aminophenyl) -3-decylsuccinimide, 1- (4-aminophenyl)- 3-hexadecyl succinimide, 1- (4-aminophenyl) -3-octadecyl succinimide, 1- (4-aminophenyl) -3-octenyl succinimide, 1- (4-aminophenyl) -3-decenyl succinimide 1- (4-aminophenyl) -3- (4-hexadecyl) -cyclohexylsuccinimide, 1 -(4-aminophenyl) -3-octylmaleimide, 1- (4-aminophenyl) -3-octyl-4-methylmaleimide, 1- (4-aminophenyl) -3-decylmaleimide, 1- (4- Aminophenyl) -3-decyl-4-methylmaleimide, 1- (4-aminophenyl) -3-heptadecylmaleimide, 1- (4-aminophenyl) -3-heptadecyl-4-methylmaleimide, 1- (4 -Aminophenyl) -3- (2-ethylhexyl) -4-methylmaleimide, 1- (4-aminophenyl) -3- (4-octyl) cyclohexyl-4-methylmaleimide, 1- (4-aminophenyl)- 3- (4-hexadecyl) cyclohexyl-4-methylmaleimide, 1- (4-aminophenyl) -3-octanoxymethylmaleimide, -(4-aminophenyl) -3-octanoxymethyl-4-methylmaleimide, 1- (4-aminophenyl) -3-decanoxymethylmaleimide, 1- (4-aminophenyl) -3-decanoxymethyl- 4-methylmaleimide, 1- (4-aminophenyl) -3-hexadecanoxymethylmaleimide, 1- (4-aminophenyl) -3-hexadecanoxymethyl-4-methylmaleimide, 1- (4- Aminophenyl) -3- (4-decyl) cyclohexanoxymaleimide, 1- (4-aminophenyl) -3- (4-decyl) cyclohexanoxy-4-methylmaleimide, 1- (4-aminophenyl)- 3- (4-hexadecyl) cyclohexanoxymaleimide, 1- (4-aminophenyl) -3- (4-hexadecyl) cyclohexanoxy 4-methyl maleimide, and the like.

The specific polymer used in the present invention becomes a terminal-modified type having a molecular weight adjusted by adding a specific monoamine compound to the reaction system when synthesizing a polyamic acid. By using this terminal-modified polymer, the orientation, storage stability, coating properties, etc. of the liquid crystal aligning agent can be improved. In addition to the specific monoamine compound, an end modifier such as acid monoanhydride, other monoamine compound, or monoisocyanate compound can be used in combination. Here, as the acid monoanhydride, for example, maleic anhydride, phthalic anhydride, itaconic anhydride, n-decyl succinic anhydride, n-dodecyl succinic anhydride, n-tetradecyl succinic anhydride , N-hexadecyl succinic anhydride and the like. Examples of other monoamine compounds include aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, and n-un. Decylamine, n-dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecylamine, n-octadecylamine, n-eicosylamine, etc. Can be mentioned. Examples of the monoisocyanate compound include phenyl isocyanate and naphthyl isocyanate.
It is preferable that the usage-amount of a specific monoamine compound occupies 20-100 mol% of all the terminal modifiers.

<Tetracarboxylic dianhydride>
The tetracarboxylic dianhydride used for the synthesis of the polyamic acid is preferably an alicyclic tetracarboxylic dianhydride. Especially, the following formula as _{R 1} in the above formula gives a group represented by the following formula (IV-1) as _{R 1} in (I) 2,3,5 tricarboxy cyclopentyl acetic dianhydride and the above formula (I) ( Particularly preferred is at least one of 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride which gives a group represented by IV-2) .

  Specific examples of other alicyclic tetracarboxylic dianhydrides include, for example, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutane. Tetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dichloro-1,2,3,4-cyclobutanetetracarboxylic dianhydride 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4 , 5-cyclohexanetetracarboxylic dianhydride, 3,3 ′, 4,4′-dicyclohexyltetracarboxylic dianhydride, cis-3,7-dibutylcycloocta-1,5-diene-1,2,5 , 6-Tetracar Acid dianhydride, 3,5,6-tricarbonyl-2-carboxynorbornane-2: 3,5: 6-dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic 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-5-methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-Hexahydro-5-ethyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-Hexahydro-7-methyl-5 (tetra Dro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-7-ethyl-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, 1,3,3a, 4,5,9b-hexahydro-8-ethyl-5 ( Tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5,8-dimethyl- 5 (Tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1, 2-c] -furan-1,3-dione, 5- (2,5-dioxotetrahydrofural) -3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, bicyclo [2.2. 2] -Oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 3-oxabicyclo [3.2.1] octane-2,4-dione-6-spiro-3'- (Tetrahydrofuran-2 ′, 5′-dione), compounds represented by the following formulas (A) and (B),

(Wherein R ¹ and R ³ represent a divalent organic group having an aromatic ring, R ² and R ⁴ represent a hydrogen atom or an alkyl group, and a plurality of R ² and R ⁴ are the same. But it may be different.)
Etc.

In addition, aliphatic tetracarboxylic dianhydrides such as butanetetracarboxylic dianhydride;
Pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenylsulfone tetracarboxylic dianhydride, 1,4,5, 8-naphthalene tetracarboxylic dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyl ether tetracarboxylic dianhydride, 3,3 ′, 4,4′-dimethyldiphenylsilanetetracarboxylic dianhydride, 3,3 ′, 4,4′-tetraphenylsilanetetracarboxylic dianhydride, 1,2,3,4-furantetracarboxylic dianhydride 4,4′-bis (3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenylsulfone dianhydride, 4,4′-bis ( 3,4-dicar Boxyphenoxy) diphenylpropane dianhydride, 3,3 ′, 4,4′-perfluoroisopropylidene diphthalic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, bis (Phthalic acid) phenylphosphine oxide dianhydride, p-phenylene-bis (triphenylphthalic acid) dianhydride, m-phenylene-bis (triphenylphthalic acid) dianhydride, bis (triphenylphthalic acid) -4 , 4′-diphenyl ether dianhydride, bis (triphenylphthalic acid) -4,4′-diphenylmethane dianhydride, ethylene glycol-bis (anhydro trimellitate), propylene glycol-bis (anhydro trimellitate) 1,4-butanediol-bis (anhydrotrimellitate), 1,6-hexanediol-bis (anhydride) Trimetrate), 1,8-octanediol-bis (anhydrotrimellitate), 2,2-bis (4-hydroxyphenyl) propane-bis (anhydrotrimellitate), the following formulas (1) to (4) An aromatic tetracarboxylic dianhydride such as a compound represented by Tetracarboxylic dianhydride may be used alone or in combination of two or more.

  Among the other alicyclic tetracarboxylic dianhydrides, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride Anhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 5- ( 2,5-dioxotetrahydrofural) -3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, cis-3,7-dibutylcycloocta-1,5-diene-1,2,5 6-tetracarboxylic dianhydride, 3,5,6-tricarbonyl-2-carboxynorbornane-2: 3,5: 6-dianhydride, 1,3,3a, 4,5,9b-hexahydro-5 -(Tetrahydro-2,5-di Xoxo-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, 1,3,3a, 4,5,9b-hexahydro-5,8-dimethyl-5- (tetrahydro-2, 5-Dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, bicyclo [2.2.2] -oct-7-ene-2,3,5,6-tetracarboxylic Acid dianhydride, 3-oxabicyclo [3.2.1] octane-2,4-dione-6-spiro-3 ′-(tetrahydrofuran-2 ′, 5′-dione), represented by the above formula (A) Of the compounds represented by the following formulas (5) to (7) Among the compounds represented by the cyclic tetracarboxylic dianhydride and the above formula (B), the alicyclic tetracarboxylic dianhydride such as the compound represented by the following formula (8) has good liquid crystal orientation. It is preferable from the viewpoint that it can be expressed. Particularly preferred are 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3,3a, 4 , 5,9b-Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, cis-3,7-dibutylcycloocta-1 , 5-Diene-1,2,5,6-tetracarboxylic dianhydride, 3,5,6-tricarbonyl-2-carboxynorbornane-2: 3,5: 6-dianhydride, 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) and represented may include compounds with the following formula (5).

Among the other tetracarboxylic dianhydrides other than the alicyclic tetracarboxylic dianhydrides, for example, butanetetracarboxylic dianhydride, pyromellitic dianhydride, 3,3 ′, 4, Examples include 4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenylsulfone tetracarboxylic dianhydride, 1,4,5,8-naphthalene tetracarboxylic dianhydride, and the like.
Among these tetracarboxylic dianhydrides, the alicyclic tetracarboxylic dianhydride is preferably 50 mol% or more based on the total tetracarboxylic dianhydrides. Further, 50 to 100 mol% of the alicyclic tetracarboxylic dianhydride is 2,3,5-tricarboxycyclopentylacetic acid dianhydride and / or 5- (2,5-dioxotetrahydro-3-furanyl)- More preferred is 3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride.

<Diamine>
Examples of the diamine used for the synthesis of the polyamic acid include p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylethane, 4,4′-diaminodiphenyl sulfide, 4,4′-diaminodiphenyl sulfone, 2,2′-dimethyl-4,4′-diaminobiphenyl, 3,3′-dimethyl-4,4′-diaminobiphenyl, 4,4′-diaminobenzanilide, 4, 4′-diaminodiphenyl ether, 1,5-diaminonaphthalene, 3,3-dimethyl-4,4′-diaminobiphenyl, 5-amino-1- (4′-aminophenyl) -1,3,3-trimethylindane, 6-amino-1- (4′-aminophenyl) -1,3,3-trimethylindane, 3,4′-diaminodiphenyl Ether, 3,3′-diaminobenzophenone, 3,4′-diaminobenzophenone, 4,4′-diaminobenzophenone, 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 [4- (4-aminophenoxy) phenyl] sulfone, 1,4 -Bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 9,9-bis (4-aminophenyl) -10- Hydroanthracene, 2,7-diaminofluorene, 9,9-dimethyl-2,7-diaminofluorene, 9,9-bis (4-aminophenol) Nyl) fluorene, 4,4′-methylene-bis (2-chloroaniline), 2,2 ′, 5,5′-tetrachloro-4,4′-diaminobiphenyl, 2,2′-dichloro-4,4 '-Diamino-5,5'-dimethoxybiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 1,4,4'-(p-phenyleneisopropylidene) bisaniline, 4,4 '-(m -Phenyleneisopropylidene) bisaniline, 2,2'-bis [4- (4-amino-2-trifluoromethylphenoxy) phenyl] hexafluoropropane, 4,4'-diamino-2,2'-bis (trifluoro) Methyl) biphenyl, 4,4′-bis [(4-amino-2-trifluoromethyl) phenoxy] -octafluorobiphenyl, 3,6-diaminocarbazole, N-methyl-3,6 Diaminocarbazole, N- ethyl-3,6-diaminocarbazole, aromatic diamines such as N- phenyl-3,6-diaminocarbazole;
1,1-metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, 4,4-diaminoheptamethylenediamine, 1 , 4-diaminocyclohexane, isophoronediamine, tetrahydrodicyclopentadienylenediamine, hexahydro-4,7-methanoindanylene methylenediamine, tricyclo [6.2.1.0 ^2,7 ] -undecylenedimethyldiamine, 4 Aliphatic and cycloaliphatic diamines such as 4,4'-methylenebis (cyclohexylamine);
2,3-diaminopyridine, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 5,6-diamino-2,3-dicyanopyrazine, 5,6-diamino-2,4 -Dihydroxypyrimidine, 2,4-diamino-6-dimethylamino-1,3,5-triazine, 1,4-bis (3-aminopropyl) piperazine, 2,4-diamino-6-isopropoxy-1,3 , 5-triazine, 2,4-diamino-6-methoxy-1,3,5-triazine, 2,4-diamino-6-phenyl-1,3,5-triazine, 2,4-diamino-6-methyl -S-triazine, 2,4-diamino-1,3,5-triazine, 4,6-diamino-2-vinyl-s-triazine, 2,4-diamino-5-phenylthiazole, 2,6- Aminopurine, 5,6-diamino-1,3-dimethyluracil, 3,5-diamino-1,2,4-triazole, 6,9-diamino-2-ethoxyacridine lactate, 3,8-diamino-6 Two primary amino groups in the molecule, such as phenylphenanthridine, 1,4-diaminopiperazine, 3,6-diaminoacridine, bis (4-aminophenyl) phenylamine, and nitrogen atoms other than the primary amino group And diaminoorganosiloxane represented by the following formula (9). These diamines can be used alone or in combination of two or more.

(In the formula, R ⁵ represents a hydrocarbon group having 1 to 12 carbon atoms, and a plurality of R ⁵ may be the same or different, p is an integer of 1 to 3, and q is 1 to 20) Is an integer.)
Among these, p-phenylenediamine, 2-methyl-1,4-phenylenediamine, 2-ethyl-1,4-phenylenediamine, 2,5-dimethyl-1,4-phenylenediamine, 2,5-diethyl-1 , 4-phenylenediamine, 2,3,5,6-tetramethyl-1,4-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl sulfide, 2,2′-dimethyl-4, 4′-diaminobiphenyl, 1,5-diaminonaphthalene, 2,7-diaminofluorene, 9,9-dimethyl-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-aminophenyl) Noxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4 ′-(p-phenylenediisopropylidene) bisaniline, 4,4 ′-(m-phenylenediisopropylidene ) Bisaniline, 1,4-cyclohexanediamine, 4,4′-methylenebis (cyclohexylamine), 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, etc. are preferred. More preferably, p-phenylenediamine, 2-methyl-1,4-phenylenediamine, 2-ethyl-1,4-phenylenediamine, 2,5-dimethyl-1,4-phenylenediamine, 2,5- It is preferable to contain 20 mol% or more of at least one diamine selected from diethyl-1,4-phenylenediamine and 2,3,5,6-tetramethyl-1,4-phenylenediamine, It is more preferable to contain 40 mol% or more.

  When the liquid crystal aligning agent of the present invention is to have pretilt angle expression, it is preferable to use at least one diamine represented by the following formula (Q-1) and the following formula (Q-2). These may be used alone or in combination of two or more.

(In the formula, X is a single bond, —O—, —CO—, —COO—, —OCO—, —NHCO—, —CONH—, —S— or an arylene group, and R ⁶ has 10 carbon atoms. An alkyl group of -20, a monovalent organic group having an alicyclic skeleton having 4 to 40 carbon atoms, or a monovalent organic group having a fluorine atom having 6 to 20 carbon atoms.)

(In the formula, X is a single bond, —O—, —CO—, —COO—, —OCO—, —NHCO—, —CONH—, —S— or an arylene group, and R ⁷ has 4 carbon atoms. It is a divalent organic group having an alicyclic skeleton of ˜40.)
In the above formula (Q-1), examples of the alkyl group having 10 to 20 carbon atoms represented by R ⁶ include n-decyl group, n-dodecyl group, n-pentadecyl group, n-hexadecyl group, n- An octadecyl group, n-eicosyl group, etc. are mentioned. Examples of the organic group having an alicyclic skeleton having 4 to 40 carbon atoms represented by R ⁶ in the above formula (Q-1) and R ⁷ in the above formula (Q-2) include cyclobutane and cyclopentane. Groups having an alicyclic skeleton derived from cycloalkane such as cyclohexane and cyclodecane; groups having a steroid skeleton such as cholesterol and cholestanol; groups having a bridged alicyclic skeleton such as norbornene and adamantane. Among these, a group having a steroid skeleton is particularly preferable. The organic group having an alicyclic skeleton may be a group substituted with a halogen atom, preferably a fluorine atom, or a fluoroalkyl group, preferably a trifluoromethyl group.

Furthermore, examples of the group having 6 to 20 carbon atoms represented by R ⁶ in the formula (Q-1) include carbon atoms such as an n-hexyl group, an n-octyl group, and an n-decyl group. A linear alkyl group having 6 or more; an alicyclic hydrocarbon group having 6 or more carbon atoms such as a cyclohexyl group or a cyclooctyl group; an organic group such as an aromatic hydrocarbon group having 6 or more carbon atoms such as a phenyl group or a biphenyl group And a group in which part or all of the hydrogen atoms are substituted with a fluoroalkyl group such as a fluorine atom or a trifluoromethyl group.

  X in the formula (Q-1) and the formula (Q-2) is a single bond, -O-, -CO-, -COO-, -OCO-, -NHCO-, -CONH-, -S. -Or an arylene group, and examples of the arylene group include a phenylene group, a tolylene group, a biphenylene group, and a naphthylene group. Of these, groups represented by —O—, —COO—, and —OCO— are particularly preferable. Specific examples of the diamine having a group represented by the above formula (Q-1) include dodecanoxy-2,4-diaminobenzene, pentadecanoxy-2,4-diaminobenzene, hexadecanoxy-2,4-diaminobenzene, octadecanoxy- Preferred examples include 2,4-diaminobenzene and compounds represented by the following formulas (10) to (19).

  Specific examples of the diamine having a group represented by the above formula (Q-2) include diamines represented by the following formulas (20) to (22).

  Of these, particularly preferred are compounds represented by the formulas (10), (11), (16), (17) and (20).

<Synthesis of polyamic acid>
The proportion of the terminal modifier containing tetracarboxylic dianhydride, diamine and specific monoamine compound used for the polyamic acid synthesis reaction is tetracarboxylic dianhydride with respect to 1 equivalent of amino group in the total of diamine and monoamine. The ratio in which the acid anhydride group in the total of the product and the dicarboxylic anhydride is 0.2 to 2 equivalents is preferable, and the ratio is more preferably 0.3 to 1.2 equivalents.
The terminal modifier is added to the reaction system during polyamic acid synthesis, and the proportion used is 0.1 to 0.1% of the total of diamine and monoamine as the proportion of monoamine containing the specific monoamine compound. 50% is preferable, and 1 to 30% is more preferable. Moreover, as a ratio of dicarboxylic acid anhydride, 0.1 to 20% is preferable with respect to the total of tetracarboxylic dianhydride and dicarboxylic acid anhydride, and 0.1 to 10% is more preferable.
The polyamic acid synthesis reaction is preferably performed in an organic solvent under a temperature condition of −20 ° C. to 150 ° C., more preferably 0 to 100 ° C.

  Here, the organic solvent is not particularly limited as long as it can dissolve the synthesized polyamic acid. For example, 1-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, 3- Amide solvents such as butoxy-N, N-dimethylpropanamide, 3-methoxy-N, N-dimethylpropanamide, 3-hexyloxy-N, N-dimethylpropanamide, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea And aprotic polar solvents such as hexamethylphosphotriamide; and phenolic solvents such as m-cresol, xylenol, phenol, and halogenated phenol. In addition, the amount (α) of the organic solvent used is usually 0.1 to 30 weights based on the total amount (β) of the terminal modifier, tetracarboxylic dianhydride and diamine compound relative to the total amount of the reaction solution (α + β). It is preferable that the amount be%.

  As the organic solvent, alcohols, ketones, esters, ethers, halogenated hydrocarbons, hydrocarbons, and the like, which are poor solvents for polyamic acid, can be used in combination as long as the polyamic acid to be produced does not precipitate. Specific examples of such poor solvents include, for example, methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol. , Ethylene glycol monomethyl ether, ethyl lactate, butyl lactate, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, diethyl oxalate, malon Acid diethyl, 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, dichloromethane 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene, hexane, heptane, octane, benzene, toluene, xylene and the like.

  As described above, a reaction solution obtained by dissolving polyamic acid is obtained. The reaction solution is poured into a large amount of poor solvent to obtain a precipitate, and the precipitate is dried under reduced pressure to obtain a polyamic acid. The polyamic acid can be purified by dissolving the polyamic acid again in an organic solvent and then precipitating with a poor solvent once or several times.

<Dehydration ring closure reaction>
The imidized polymer constituting the liquid crystal aligning agent of the present invention can be synthesized by dehydrating and cyclizing a part or all of the polyamic acid. In the imidized polymer used in the present invention, the ratio of repeating units having an imide ring in all repeating units (hereinafter also referred to as “imidation ratio”) is 40 mol% or more, preferably 50 mol% or more. By using a polymer having an imidization ratio of 40 mol% or more, a liquid crystal aligning agent capable of forming a liquid crystal alignment film having a short afterimage erasing time can be obtained.
The polyamic acid is dehydrated and closed by (i) a method of heating the polyamic acid, or (ii) dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydrating ring-closing catalyst to this solution, and heating as necessary. By the method.
The reaction temperature in the method of heating the polyamic acid (i) is preferably 50 to 200 ° C, more preferably 60 to 170 ° C. When the reaction temperature is less than 50 ° C., the dehydration ring-closing reaction does not proceed sufficiently, and when the reaction temperature exceeds 200 ° C., the molecular weight of the imidized polymer obtained may decrease.

  On the other hand, in the method (ii) of adding a dehydrating agent and a dehydrating ring-closing catalyst to the polyamic acid solution, an acid anhydride such as acetic anhydride, propionic anhydride, or trifluoroacetic anhydride is used as the dehydrating agent. Can do. The amount of the dehydrating agent used depends on the desired imidization ratio, but is preferably 0.01 to 20 mol per 1 mol of the polyamic acid repeating unit. Moreover, as a dehydration ring closure catalyst, tertiary amines, such as a pyridine, a collidine, a lutidine, a triethylamine, can be used, for example. However, it is not limited to these. The amount of the dehydration ring closure catalyst used is preferably 0.01 to 10 moles per mole of the dehydrating agent used. The imidation rate can be increased as the amount of the above dehydrating agent and dehydrating ring-closing agent increases. In addition, as an organic solvent used for dehydration ring closure reaction, the organic solvent illustrated as what is used for the synthesis | combination of a polyamic acid can be mentioned. And reaction temperature of dehydration ring closure reaction becomes like this. Preferably it is 0-180 degreeC, More preferably, it is 10-150 degreeC. Moreover, the obtained specific polymer can be refine | purified by performing operation similar to the purification method of a polyamic acid with respect to the reaction solution obtained in this way.

<Logarithmic viscosity of polymer>
The polyamic acid obtained as described above preferably has a logarithmic viscosity (η _ln ) of 0.05 to 10 dl / g, more preferably 0.05 to 5 dl / g.
The value of the logarithmic viscosity (η _ln ) in the present invention is determined by measuring the viscosity at 30 ° C. for a solution having a concentration of 0.5 g / 100 ml using N-methyl-2-pyrrolidone as a solvent. ).

[Liquid crystal aligning agent]
The liquid crystal aligning agent of the present invention is constituted by dissolving and containing the polyamic acid and / or its imidized polymer in an organic solvent.
The temperature at the time of preparing the liquid crystal aligning agent of this invention becomes like this. Preferably it is 0 to 200 degreeC, More preferably, it is 20 to 60 degreeC.

  Examples of the organic solvent constituting the liquid crystal aligning agent of the present invention include 1-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 Ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, 3-butoxy-N, N-dimethylpropanamide, 3-methoxy-N, N-dimethylpropanamide, Examples include 3-hexyloxy-N, N-dimethylpropanamide, diethyl carbitol, ethyl carbitol acetate, butyl carbitol, triethylene glycol dimethyl ether, and the like. Of these, 1-methyl-2-pyrrolidone, γ-butyrolactam, and ethylene glycol-n-butyl ether (butyl cellosolve) are particularly preferable because they exhibit good printability.

  The solid content concentration in the liquid crystal aligning agent of the present invention is selected in consideration of viscosity, volatility, etc., but is preferably 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 to form a coating film that becomes a liquid crystal alignment film. When the solid content concentration is less than 1% by weight, the coating film thickness is When the solid content concentration exceeds 10% by weight, the film thickness of the coating film becomes excessive and a good liquid crystal alignment film cannot be obtained. In addition, the viscosity of the liquid crystal aligning agent increases, resulting in poor coating characteristics.

  The liquid crystal aligning agent of the present invention may contain a functional silane-containing compound from the viewpoint of improving the adhesion to the substrate surface within a range not impairing the target physical properties. Examples of such functional silane-containing compounds include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, and N- (2-aminoethyl). -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-amino Propyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl- , 4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N -Bis (oxyethylene) -3-aminopropyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, etc. can be mentioned. Examples of such epoxy compounds 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, 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, 3- (N-Ariru N Gurishijiru) aminopropyltrimethoxysilane, 3- (N, N-diglycidyl) and aminopropyl trimethoxy silane can be cited. The blending ratio of these functional silane-containing compounds is preferably 40 parts by weight or less, more preferably 0.1 to 30 parts by weight with respect to 100 parts by weight of the polymer.

<Liquid crystal display element>
The liquid crystal display element obtained using the liquid crystal aligning agent of this invention can be manufactured, for example with the following method.

(1) The liquid crystal aligning agent of the present invention is applied to one surface of a substrate provided with a patterned transparent conductive film by an offset printing method, a spin coating method, or an ink jet printing method, and then the coated surface is heated. To form a coating film. Here, as the substrate, for example, a glass such as float glass or soda glass; a transparent substrate made of a plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, or polycarbonate 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. For patterning these transparent conductive films, a photo-etching method or a method using a mask in advance is used. When applying the liquid crystal aligning agent, in order to further improve the adhesion between the substrate surface and the transparent conductive film and the coating film, a functional silane-containing compound, a functional titanium-containing compound, or the like is previously applied to the surface of the substrate. You can also The heating temperature after application of the liquid crystal aligning agent is 80 to 300 ° C, preferably 120 to 250 ° C. In addition, the liquid crystal aligning agent of the present invention containing a polyamic acid forms a coating film that becomes an alignment film by removing the organic solvent after coating, but further proceeds with dehydration ring closure by further heating, and is further imidized. It can also be set as a coating film. The film thickness of the coating film to be formed is usually 0.001 to 1 μm, preferably 0.005 to 0.5 μm.

(2) A rubbing process is performed in which the formed coating film surface is rubbed in a certain direction with a roll wound with a cloth made of a fiber such as nylon, rayon, or cotton. Thereby, the orientation ability of a liquid crystal molecule is provided to a coating film, and it becomes a liquid crystal aligning film. Further, by partially irradiating the liquid crystal alignment film formed of the liquid crystal alignment agent of the present invention with ultraviolet rays as disclosed in, for example, JP-A-6-222366 and JP-A-6-281937. A resist film is partially formed on the surface of the liquid crystal alignment film that has been subjected to a treatment for changing the pretilt angle or a rubbing treatment as disclosed in JP-A-5-107544, which is different from the previous rubbing treatment. The visibility characteristics of the liquid crystal display element can be improved by removing the resist film after performing the rubbing treatment in the direction and changing the liquid crystal alignment ability of the liquid crystal alignment film.

(3) Two substrates on which the liquid crystal alignment film is formed as described above are manufactured, and the two substrates are separated by a gap (cell gap) so that the rubbing directions in the respective liquid crystal alignment films are orthogonal or antiparallel. ), And the periphery of the two substrates are bonded together using a sealant, and liquid crystal is injected and filled in the cell gap defined by the substrate surface and the sealant, and the injection hole is sealed. A liquid crystal cell is constructed. A polarizing plate is disposed on the outer surface of the liquid crystal cell, that is, on the other surface side of each substrate constituting the liquid crystal cell, and the polarization direction thereof coincides with or is orthogonal to the rubbing direction of the liquid crystal alignment film formed on one surface of the substrate. A liquid crystal display element is obtained by pasting together. Here, 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. Liquid crystals, biphenylcyclohexane liquid crystals, pyrimidine liquid crystals, dioxane liquid crystals, bicyclooctane liquid crystals, cubane liquid crystals, and the like can be used. Further, for these liquid crystals, for example, cholesteric liquid crystals such as cholestyl chloride, cholesteryl nonate, cholesteryl carbonate, and chiral agents such as those sold under the trade names “C-15” and “CB-15” (manufactured by Merck). Etc. can also be used. Furthermore, a ferroelectric liquid crystal such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate can also be used. Further, as a polarizing plate to be bonded to the outer surface of the liquid crystal cell, a polarizing film or an H film in which a polarizing film called an H film that absorbs iodine while sandwiching and stretching polyvinyl alcohol is sandwiched between cellulose acetate protective films. The polarizing plate which consists of itself can be mentioned.

Here, 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. Liquid crystals, biphenylcyclohexane liquid crystals, pyrimidine liquid crystals, dioxane liquid crystals, bicyclooctane liquid crystals, cubane liquid crystals, and the like can be used. Further, for these liquid crystals, for example, cholesteric liquid crystals such as cholestyl chloride, cholesteryl nonate, cholesteryl carbonate, and chiral agents such as those sold under the trade names “C-15” and “CB-15” (manufactured by Merck). Etc. can also be used. Furthermore, a ferroelectric liquid crystal such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate can also be used.
Further, as a polarizing plate to be bonded to the outer surface of the liquid crystal cell, a polarizing film or an H film in which a polarizing film called an H film that absorbs iodine while sandwiching and stretching polyvinyl alcohol is sandwiched between cellulose acetate protective films. The polarizing plate which consists of itself can be mentioned.

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

[Orientation evaluation]
[Orientation of liquid crystal]
The presence or absence of anomalous domains when the voltage is turned on / off (applied / released) to the liquid crystal display element is observed with a polarizing microscope. “○” indicates that there are no abnormal domains, and “△” indicates that there are slight abnormal domains. ”, A case where many abnormal domains were observed was determined as“ x ”.

[Storage stability of liquid crystal alignment agent]
The liquid crystal aligning agent is allowed to stand for 4 months in a thermostatic bath at 5 ° C., and the viscosity of the liquid crystal aligning agent before and after being left is measured using an E-type viscometer, and the viscosity reduction rate is based on the following formula (ii) Asked.

  The case where the viscosity reduction rate was 20% or more was rated as “x”, and the case where it was less than 20% was rated as “◯”. The results are shown in Table 3.

<Synthesis example of specific monoamine>
Monomer Synthesis Example 1: Synthesis Example of 1- (4-Aminophenyl) -3-octadecylsuccinimide In a 300 ml three-necked flask purged with nitrogen gas, 9.66 g (0.07 mol) of 4-nitroaniline and 70 ml of acetic acid were added. The solution is stirred while flowing the gas to dissolve the solid matter. To this, 24.64 g (0.07 mol) of octadecyl succinic anhydride is added, and the mixture is refluxed for 20 hours under nitrogen. After cooling the reaction solution to room temperature, 70 ml of methanol is added and left overnight. The precipitated solid was separated by filtration, washed with methanol, and dried to obtain 28.1 g (0.06 mol, yield 85%) of 1- (4-nitrophenyl) -3-octadecylsuccinimide.

  Next, 27.37 g (0.058 mol) of 1- (4-nitrophenyl) -3-octadecylsuccinimide synthesized above, 100 ml of ethanol, 100 ml of THF, and 25 g of reduction catalyst Pd / C were added to a 500 ml flask purged with nitrogen gas. Stir at 70 ° C. for 1 hour. Thereto, 42.5 ml (43.75 g) of hydrazine monohydrate is added and heated to reflux for 6 hours for reaction. Pd / C is filtered off and the solution is concentrated on a rotary evaporator. The obtained crude product was dissolved by heating with N-methyl-2-pyrrolidone, cooled and recrystallized, and 15.89 g (0.036 mol, 0.036 mol, 1- (4-aminophenyl) -3-octadecylsuccinimide as the target product was obtained. Yield 62%) was obtained. This was designated as specific monoamine A.

Monomer Synthesis Example 2: Synthesis Example of 1- (4-Aminophenyl) -3-heptadecyl-4-methylmaleimide 31.5 g (0.25 mol) of dimethylmaleic anhydride and N- 89.0 g (0.5 mol) of bromosuccinimide, 1.0 g (4.15 mmol) of benzoyl peroxide and 1,500 ml of carbon tetrachloride were added, and the mixture was heated to reflux for 5 hours. The reaction solution was cooled to room temperature, allowed to stand at room temperature overnight, and then filtered. After the filtrate was washed with water, the organic layer was concentrated on a rotary evaporator. The resulting crude oily product was distilled under high vacuum (120-125 ° C./2 mmHg), and 20.0 g (0.1 mol, yield 39) of 3-bromomethyl-4-methylmaleic anhydride as an intermediate was obtained. %).

  Next, in a 2,000 mL three-necked flask replaced with argon gas, 16.4 g (80 mmol) of 3-bromomethyl-4-methylmaleic anhydride obtained above, 1.52 g (8.0 mmol) of copper iodide, After adding 400 mL of diethyl ether and 160 mL of HMPA (hexamethylphosphoric triamide), the mixture was cooled to −5 to 0 ° C. under argon gas flow. While stirring the mixed solution, a 400 mL ether solution of 400 mmol hexadecylmagnesium bromide prepared separately was dropped over about 20 minutes. The mixture was returned to room temperature and further stirred for 8 h. Thereafter, 600 mL of 4N-sulfuric acid diluted with 600 mL of diethyl ether was added to make the solution acidic. The separated aqueous layer was further washed with 600 mL of ether, and the organic layers were combined. The organic layer was washed with water and dehydrated with sodium sulfate, and then the solution was concentrated on a rotary evaporator to obtain an oily crude product. This crude product was purified on a silica gel column using petroleum ether / ethyl acetate (19: 1) mixed solution as a developing solvent, and 14.0 g of 3-heptadecyl-4-methylmaleic anhydride (0.04 mol yield 50). %).

  Next, 9.66 g (0.07 mol) of 4-nitroaniline and 70 ml of acetic acid are added into a 300 ml three-neck flask purged with nitrogen gas. The solution is stirred while flowing nitrogen gas to dissolve the solid matter. To this, 24.5 g (0.07 mol) of 2-heptadecyl-3-methylmaleic anhydride obtained above is added and refluxed for 20 hours under nitrogen. After the reaction solution is cooled to room temperature, 70 ml of methanol is added and left overnight. The solid was separated by filtration, washed with methanol and dried to obtain 27.97 g (0.060 mol yield 85%) of 1- (4-nitrophenyl) -3-heptadecyl-4-methylmaleimide.

  Next, 24.44 g (0.052 mol) of 1- (4-nitrophenyl) -3-heptadecyl-4-methylmaleimide, 100 ml of ethanol, 100 ml of THF, and 25 g of reduction catalyst Pd / C were added to a 500 ml flask purged with nitrogen gas. Stir for 1 hour at ° C. Add 38 ml (39.2 g) of hydrazine monohydrate and heat to reflux for 6 hours to react. Pd / C is filtered off and the solution is concentrated on a rotary evaporator. The obtained crude product was heated and dissolved with N-methyl-2-pyrrolidone, cooled and recrystallized, and 13.73 g of 1- (4-aminophenyl) -3-heptadecyl-4-methylmaleimide as the target product ( 0.031 mol yield 60%). This was designated as specific monoamine B.

Monomer synthesis example 3: Synthesis example of 1- (4-aminophenyl) -3-hexadecanoxymethyl-4-methylmaleimide To a 500 ml three-necked flask were added 9.66 g (0.07 mol) of 4-nitroaniline and 70 ml of acetic acid. After that, the solution is stirred while flowing nitrogen gas to dissolve the solid matter. Next, 14.35 g (0.07 mol) of 3- (bromomethyl) -4-methylmaleic anhydride described in Monomer Synthesis Example 2 is added, and the mixture is refluxed for 20 hours under nitrogen. After cooling the reaction solution to room temperature, 70 ml of methanol is added and left overnight. The solid content was separated by filtration, washed with methanol, and dried to obtain 16.84 g (0.052 mol, yield 74%) of 1- (4-nitrophenyl) -3-bromomethyl-4-methylmaleimide.

  Next, in a 500 ml three-necked flask, 15.93 g (0.049 mol) of 1- (4-nitrophenyl) -3-bromomethyl-4-methylmaleimide, 12.94 g (0.049 mol) of 1-hexadecanol sodium salt, and After adding 100 ml of dimethyl sulfoxide, the mixture is stirred at 100 ° C. for 10 hours to be reacted. After cooling the reaction solution to room temperature, 70 ml of methanol is added and left overnight. The solid content was separated by filtration, washed with methanol and dried to obtain 19.68 g (0.041 mol yield 83%) of 1- (4-nitrophenyl) -3-hexadecanoxymethyl-4-methylmaleimide. It was.

  Next, 25.17 g (0.052 mol) of 1- (4-nitrophenyl) -3-hexadecanoxymethyl-4-methylmaleimide, ethanol 100 ml, THF 100 ml, reduction catalyst Pd / Add C25g and stir at 70 ° C for 1 hour. Thereafter, 38 ml (39.2 g) of hydrazine monohydrate is added and heated to reflux for 6 hours to react. Pd / C is filtered off and the solution is concentrated on a rotary evaporator. The obtained crude product was heated and dissolved with N-methyl-2-pyrrolidone, cooled and recrystallized, and the desired product 1- (4-aminophenyl) -3-hexadecanoxymethyl-4-methylmaleimide was obtained. 16.60 g (0.036 mol yield 70%) was obtained. Specific monoamine C was designated.

Synthesis Examples 1-8 and Comparative Synthesis Examples 1-2
To N-methyl-2-pyrrolidone, the composition shown in Tables 1 and 2 was added in the order of diamine and tetracarboxylic dianhydride (shown as “acid anhydride” in the table) in this order, and the solid content concentration was 20% by weight. And reacted at 60 ° C. for 4 hours. Thereafter, the specific monoamines shown in Table 1 and Table 2 were added and reacted for another 30 minutes to obtain polyamic acid polymers (A-1) to (A-10). The resulting polyamic acid polymer was added with pyridine and acetic anhydride in the number of moles shown in Table 1 with respect to the total amount of the polyacic acid polymer, and then heated to 110 ° C. for 4 hours for dehydration ring closure reaction. The obtained solution was reprecipitated with diethyl ether, and then recovered and dried under reduced pressure, whereby (B-1) to (B) which are imidized polymers having logarithmic viscosities and imidization ratios shown in Table 1 and Table 2. -6) and (B-9) to (B-10) were obtained.

  In Tables 1 and 2, for diamine compounds and acid anhydrides, the numbers in parentheses indicate the content ratio, and the meanings of the symbols in the tables are as follows.

<Diamine compound>
Diamine 1: 1- (3,5-diaminophenyl) -3-octadecylsuccinimide diamine 2: 4,4-diaminodiphenylmethane <tetracarboxylic dianhydride>
T-1: 2,3,5-tricarboxycyclopentyl acetic acid dianhydride T-2: 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid Acid anhydride T-3: Pyromellitic dianhydride T-4: 1,2,3,4-cyclobutanetetracarboxylic dianhydride

<Monoamine compound>
Specific monoamine A: 1- (4-aminophenyl) -3-octadecylsuccinimide Specific monoamine B: 1- (4-aminophenyl) -3-heptadecyl-4-methylmaleimide Specific monoamine C: 1- (4-aminophenyl) -3-Hexadecanoxymethyl-4-methylmaleimide comparative monoamine: 4-octadecylaniline

Example 1
The imidized polymer (B-1) and polyamic acid polymer (A-7) obtained in Synthesis Example 1 were mixed with a γ-butyrolactone / N-methyl-2-pyrrolidone / butyl cellosolve mixed solution (weight ratio 40/30 / 30) to obtain a solution having a solid content concentration of 3.5% by weight and 6% by weight. Then, it filtered using the filter with a hole diameter of 0.2 micrometer, and the orientation agent 1 was prepared. A solution having a solid concentration of 6% by weight was used as a storage stability evaluation sample.
A film having a dry film thickness of about 0.06 μm is formed by a spin coater on a glass substrate having a patterned ITO film having a thickness of 1 mm using the film-forming composition prepared to a solid content concentration of 3.5% by weight. A liquid crystal alignment film-coated substrate on which was formed was prepared.

  Next, after applying an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm to the outer edges of the pair of transparent electrodes / transparent electrode substrates having the liquid crystal alignment film of the liquid crystal alignment film coated substrate, the liquid crystal alignment film The adhesive was cured by overlapping and pressing so that the surfaces were opposed. Next, a negative type liquid crystal (MLC-6608, manufactured by Merck & Co., Inc.) is filled between the substrates from the liquid crystal injection port, and then the liquid crystal injection port is sealed with an acrylic photo-curing adhesive, and polarizing plates are formed on both sides of the substrate. Were laminated to prepare a liquid crystal display element. The orientation of the obtained liquid crystal display element was evaluated. The results are summarized in Table 4.

Examples 2-9
In the same manner as in Example 1, the polymer was dissolved in a γ-butyrolactone / N-methyl-2-pyrrolidone / butyl cellosolve mixed solution (weight ratio 40/30/30) according to the formulation shown in Table 3 to obtain a solid content concentration. The compositions for forming an alignment film (alignment agents 2-6, 9-11) were prepared as 3.5 wt% and 6 wt% solutions, and the storage stability and alignment properties were used in the same manner as in Example 1. Evaluated. The results are also shown in Table 4.

Comparative Examples 1-3
Similarly to Example 1, the polymers listed in Table 3 were dissolved in a γ-butyrolactone / N-methyl-2-pyrrolidone / butyl cellosolve mixed solution (weight ratio 40/30/30) to obtain a solid content concentration of 3.5. Alignment film-forming compositions (alignment agents 7, 8 and 12) were prepared using the solutions of 5% by weight and 6% by weight, and the storage stability and orientation were evaluated in the same manner as in Example 1 using this composition. The results are also shown in Table 4.

Claims (3)

Formula (I)

Here, R ₁ represents a tetravalent organic group.
A tetracarboxylic dianhydride represented by the following formula (II):

Here, R ₂ represents a divalent organic group.
And the following formula (III-1), (III-2) or (III-3):

Here, R ₃ , R ₄ and R ₅ are each independently a linear, branched or cyclic alkyl group or fluoroalkyl group having 1 to 30 carbon atoms, or a linear or branched group having 4 to 30 carbon atoms. Or a cyclic alkenyl group or a fluoroalkenyl group, and A is a hydrogen atom or a methyl group.
A liquid crystal aligning agent comprising a polymer obtained by reacting a monoamine compound represented by formula (1) and / or an imidized polymer thereof. 2. The liquid crystal aligning agent according to claim 1, wherein R ₁ in the formula (I) is any one of tetravalent groups represented by the following formulas (IV-1) and (IV-2).

A liquid crystal display element comprising a liquid crystal alignment film obtained from the liquid crystal aligning agent according to claim 1.