JP5516836B2 - Vertical alignment type liquid crystal aligning agent and vertical alignment type liquid crystal display element - Google Patents

Description

  The present invention relates to a liquid crystal display element having a vertical alignment liquid crystal aligning agent and a vertical alignment liquid crystal alignment film. More specifically, the present invention relates to a vertical alignment type liquid crystal aligning agent that has excellent vertical alignment properties, exhibits good electrical characteristics, and has excellent coating properties by a printing method.

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 type liquid crystal display element having a so-called TN type (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.

In recent years, the development of new liquid crystal display elements has also been active, and as one of them, two electrodes for driving a liquid crystal are arranged in a comb shape on one substrate, and an electric field parallel to the substrate surface is arranged. A lateral electric field type liquid crystal display element that generates liquid crystal and controls liquid crystal molecules has been proposed. This element is generally called an in-plane switching type (IPS type), and is known for its excellent wide viewing angle characteristics. Recently, an optical compensation film is used to further improve the wide viewing angle characteristics, so that it is possible to obtain a wide viewing angle comparable to that of a cathode ray tube without tone reversal or color change.
As a liquid crystal display element different from the above, a vertical alignment type called an MVA (Multi domain Vertical Alignment) method or a PVA (Patterned Vertical Alignment) method in which liquid crystal molecules having negative dielectric anisotropy are aligned perpendicularly to a substrate. Liquid crystal display elements have been proposed. These MVA type and PVA type liquid crystal display elements are excellent not only in viewing angle and contrast, but also in terms of manufacturing processes, such as not having to perform a rubbing treatment in forming a liquid crystal alignment film.

  In recent years, a method called an ODF (One-Drop-Filling) method has been used as a liquid crystal injection method in a liquid crystal display element, particularly when a large substrate is used, instead of the conventional vacuum injection method. This is a method of injecting liquid crystal by dropping liquid crystal microdroplets on a substrate, then bonding the substrates together, and spreading the liquid crystal over the entire display element. By using this method, there is an advantage that the number of processes and the cycle time can be reduced. On the other hand, the disadvantage is the occurrence of orientation failure called ODF unevenness. This is considered to occur because the vertical alignment on the surface of the liquid crystal alignment film is disturbed by the impact when the liquid crystal is dropped and the flow when the liquid crystal spreads. In order to reduce this defect, it is expected that improving the vertical alignment, such as increasing the amount of the vertical alignment component, is effective, but it is difficult because it causes a decrease in other characteristics such as printability and electrical characteristics. Expected to be. From such a background, development of a vertical alignment type liquid crystal alignment film excellent in total balance of printability and electrical characteristics while improving ODF unevenness has been awaited.

  An object of the present invention is to provide a vertical alignment type liquid crystal aligning agent having a high vertical alignment ability and having printability and good electrical characteristics such as a high voltage holding characteristic and a low afterimage, and an alignment film formed therefrom. It is to provide a 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. First, an amic acid repeating unit represented by the following formula (I-1) and an imide repeating unit represented by the following formula (I-2): 100 parts by weight of a polymer composed of at least one repeating unit (hereinafter sometimes referred to as “specific polymer”) and at least in the molecule represented by each of the following formulas (II-1) and (II-2) 1 to 50 parts by weight of at least one epoxy-containing compound selected from the group consisting of compounds containing two epoxy groups (hereinafter sometimes referred to as “specific epoxy compounds”), and 0.1 to 20 weights of an amine compound described later. It is achieved by a vertical alignment type liquid crystal aligning agent characterized by being prepared by mixing parts.

(Here, P ¹ represents a tetravalent organic group derived from tetracarboxylic dianhydride and Q ¹ represents a divalent organic group derived from diamine.)

(Here, P ² represents a tetravalent organic group derived from tetracarboxylic dianhydride and Q ² represents a divalent organic group derived from diamine.)

(Here, a is an integer of 2 to 6, b is an integer of 1 to 4, R ^c is an organic group containing an a-valent aromatic ring, and R ^d contains a b-valent aromatic ring. It is an organic group.)
According to the present invention, the above objects and advantages of the present invention are secondly provided. The vertical alignment liquid crystal display element comprises a vertical alignment liquid crystal alignment film formed from the liquid crystal alignment agent of the present invention. Is achieved.

Since the vertical alignment type liquid crystal alignment film formed by the vertical alignment type liquid crystal alignment agent of the present invention has a high vertical alignment ability, a liquid crystal alignment film excellent in ODF unevenness resistance can be obtained. At the same time, a suitable vertical alignment type liquid crystal alignment film having printability, high voltage holding characteristics, and good afterimage characteristics can be obtained.
The liquid crystal display element of the present invention can be effectively used in various devices, and is suitable for display devices such as desk calculators, watches, table clocks, mobile phones, counting display boards, word processors, personal computers, and liquid crystal televisions. Can be used.

  Hereinafter, the present invention will be described in detail.

  The vertical alignment type liquid crystal aligning agent in the present invention (hereinafter also referred to as “liquid crystal aligning agent of the present invention”) contains a specific polymer and a specific epoxy compound as described above.

[Specific polymer]
A specific polymer consists of a polymer containing an amic acid repeating unit and / or an imide repeating unit. Among the above repeating units, a polymer comprising an amic acid repeating unit (hereinafter also referred to as “polyamic acid polymer”) is obtained, for example, by reacting a tetracarboxylic dianhydride and a diamine compound in an organic solvent. In addition, a polymer containing an imide repeating unit (hereinafter also referred to as “imidized polymer”) can be obtained by dehydrating and ring-closing the amic acid portion of the polyamic acid polymer. The imidized polymer includes those in which all of the repeating units are imidized and those that are partially imidized. Further, a part of the imide ring may be an isoimide ring.

A preferred polymer in the present invention includes a polymer containing both a polyamic acid polymer and an imidized polymer, a prepolymer having an amic acid structure, and a block copolymer obtained from a prepolymer having an imide structure. And an imidized polymer obtained by partially dehydrating and ring-closing the polyamic acid polymer. Hereafter, the manufacturing method of the polyamic acid polymer and imidized polymer which can be used for this invention is described. Hereafter, the manufacturing method of the polyamic acid polymer and imidized polymer which can be used for this invention is described.
Examples of the tetracarboxylic dianhydride that can be used in the polyamic acid polymer and / or imidized polymer constituting the liquid crystal aligning agent in the present invention include, for example, butanetetracarboxylic dianhydride, the following formula (1):

Here, R ⁴ , R ⁵ , R ⁶ and R ⁷ are each independently a hydrogen atom, a halogen atom or a monovalent organic group.
Cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3 ′, 4 , 4′-bicyclohexyltetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 1,2,4-tricarboxycyclopentylacetic acid dianhydride, bicyclo [2.2.1] heptane -2,3,5,6-tetracarboxylic dianhydride, 3,5,6-tricarboxynorbornane-2-acetic dianhydride, tetracyclo [4.4.0.1 ^2,7 1 ^7.10 ] Dodecane-3,4,8,9-tetracarboxylic dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, the following formula (2)

Here, R ³ is a hydrogen atom or a monovalent organic group.
Dicarboxylic dianhydride represented by the formula: 5- (2,5-dioxotetrahydrofural) -3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, bicyclo [2.2.2] -oct -4-ene-2,3,5,6-tetracarboxylic 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), 3,5,6-tricarboxy-2-carboxy Norbornane-2: 3,5: 6-dianhydride, 4,9-dioxatricyclo "5.3.1.0 ^2,6 " undecane-3,5,8,10-tetraone, the following formula (3 ) And (4) aliphatic and alicyclic tetra Carboxylic acid dianhydride;

Here, R ⁸ and R ⁹ represent a divalent organic group having an aromatic ring, R ¹⁰ and R ¹¹ represent a hydrogen atom or an alkyl group, and a plurality of R ¹⁰ and R ¹¹ may be the same. May be different.

  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′-bi (3,4-dicarboxyphenoxy) diphenylpropane dianhydride, 3,3 ′, 4,4′-perfluoroisopropylidenediphthalic dianhydride, 2,2 ′, 3,3′-biphenyltetracarboxylic acid Dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, bis (phthalic acid) phenylphosphine oxide dianhydride, ethylene glycol-bis (anhydrotrimellitate), propylene glycol-bis (Anhydro trimellitate), 1,4-butanediol-bis (anhydro trimellitate), 1,6-hexanediol-bis (anhydro trimellitate), 1,8-octanediol-bis (an Hydrotrimellitate), 2,2-bis (4-hydroxyphenyl) propane-bis (anhydrotrimellitate) Formula (5) and aromatic tetracarboxylic dianhydrides such as compounds represented by - (8). These may be used alone or in combination of two or more.

  Examples of the cyclobutanetetracarboxylic dianhydride represented by the above formula (1) include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2,3,4- Cyclobutanetetracarboxylic dianhydride, 1,2-diethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride 1,3-diethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dichloro-1,2,3,4-cyclobutanetetracarboxylic dianhydride, and 1,2, Mention may be made of 3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride.

  Examples of the dicarboxylic dianhydride represented by the above formula (2) include 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 (tetrahydro-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 and 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 Can be mentioned.

  Among these, tetracarboxylic dianhydrides represented by the above formula (2) such as 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 (tetrahydro-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; 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, At least one tetracarboxylic dianhydride selected from the above is preferably 40 mol% or more, more preferably 50 mol% or more with respect to the total tetracarboxylic dianhydride. It is particularly preferable to contain at least%.

[Diamine compound]
Examples of the diamine compound that can be used for the polyamic acid polymer and / or imidized polymer constituting the liquid crystal aligning agent in the present invention include p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane, 4 , 4'-diaminodiphenylethane, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 3,3'-dimethyl-4,4'-diaminobiphenyl, 4,4'-diaminobenzanilide, 4,4′-diaminodiphenyl ether, 1,5-diaminonaphthalene, 2,2′-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-aminophenyl) 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 (trifluoromethyl) biphenyl, 4,4'-bis [(4-amino-2-trifluoromethyl) phenoxy] -octafluorobiphenyl, 4- (4-n-heptylcycline) Aromatic diamines such as hexyl) phenoxy-2,4-diaminobenzene;
1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, 4,4-diaminoheptamethylenediamine, 1,4-diaminocyclohexane, 1,4 -Bis (aminomethyl) -bicyclo [2,2,1] heptane, 1,4-bis (aminopropyl) -bicyclo [2,2,1] heptane, 1,3-bis (aminomethyl) cyclohexane, 1, 4-bis (aminomethyl) cyclohexane, 1,3-bis (aminopropyl) cyclohexane, metaxylylenediamine, paraxylylenediamine, isophoronediamine, tetrahydrodicyclopentadienylenediamine, hexahydro-4,7-methanoin Mite diamine methylenediamine Aliphatic and alicyclic diamines such as tricyclo [6.2.1.0 ^2,7 ] -undecylenedimethyldiamine, 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 Phenylphenanthridine, 1,4-diaminopiperazine, 3,6-diaminoacridine, bis (4-aminophenyl) phenylamine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, N-ethyl Two primary amino groups in the molecule, such as −3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N, N′-di (4-aminophenyl) -benzidine and the primary amino A diamine having a nitrogen atom other than a group;
Diaminoorganosiloxane represented by the following formula (9);

(Wherein R ¹² represents a hydrogen atom or a monovalent organic group, R ¹³ represents a methylene group or an alkylene group having 2 to 20 carbon atoms, and a plurality of R ¹² and R ¹³ are the same or different, respectively. And p is an integer of 1 to 20.)
Examples include compounds represented by the following formulas (10) to (12). These diamine compounds can be used alone or in combination of two or more.

(Where X ¹ is a single bond, —O—, —CO—, —COO—, —OCO—, —NHCO—, —CONH—, —S—, a methylene group, or an alkylene group having 2 to 6 carbon atoms. Or a phenylene group, and R ¹ is a monovalent organic group having an alkyl group having 10 to 20 carbon atoms, an alicyclic skeleton having 4 to 40 carbon atoms, or a monovalent organic group having a fluorine atom having 6 to 20 carbon atoms. R ² is an organic group, and R ² is a divalent organic group having an alicyclic skeleton having 4 to 40 carbon atoms or a divalent organic group having a fluorine atom having 5 to 30 carbon atoms, and in formula (11) A plurality of X ¹ may be the same or different from each other, and q is an integer of 1 to 20.)
Among these, a compound represented by the above formula (10), for example, a diamine represented by each of the following formulas (13) to (27); and / or

Compounds represented by the above formula (11), for example, diamines represented by the following formulas (28) to (32);

Is preferably used as at least one part of the total diamine, more preferably 8 mol% or more, and more preferably 10 mol% or more, based on the total diamine. Further preferred.

  Further, as other diamine compounds, p-phenylenediamine, 2-methyl-1,4-phenylenediamine, 2-ethyl-1,4-phenylenediamine are used to sufficiently obtain the effect of the liquid crystal aligning agent of the present invention. 2,5-dimethyl-1,4-phenylenediamine, 2,5-diethyl-1,4-phenylenediamine and 2,3,5,6-tetramethyl-1,4-phenylenediamine The content of at least one diamine is preferably 20 mol% or more, more preferably 40 mol% or more, based on the total diamine.

[Synthesis of polyamic acid]
The ratio of the tetracarboxylic dianhydride and the diamine used for the polyamic acid synthesis reaction is 0.5 to 2% of the acid anhydride group of the tetracarboxylic dianhydride with respect to 1 equivalent of the amino group of the diamine. A ratio of 0 equivalent is preferable, and a ratio of 0.7 to 1.2 equivalent 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, dimethyl sulfoxide And aprotic polar solvents such as γ-butyrolactone, tetramethylurea and hexamethylphosphortriamide; and phenolic solvents such as m-cresol, xylenol, phenol and halogenated phenol. The amount of organic solvent used (α) is such that the total amount (β) of tetracarboxylic dianhydride and diamine compound is 0.1 to 30% by weight based on the total amount of the reaction solution (α + β). It is preferable that

  In addition, the said organic solvent can use together the alcohol, ketone, ester, ether, halogenated hydrocarbon, hydrocarbon, etc. which are poor solvents of a polyamic acid in the range in which the polyamic acid to produce | generate 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, isoamylpropionate, isoamylisobutyrate, diisopentyl A Or the like can be mentioned Le.

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

[Synthesis of imidized polymer]
The imidized polymer constituting the liquid crystal aligning agent of the present invention can be synthesized by dehydrating and ring-closing the polyamic acid. The imidized polymer used in the present invention may be partially dehydrated and ring-closed with an imidation rate of less than 100%. The “imidation ratio” herein is a value representing the ratio of the repeating unit having an imide ring or an isoimide ring as a percentage in all repeating units of the polymer. Imidization of the polyamic acid polymer and / or imidized polymer used in the present invention is 30% or more, 40% or more is favorable preferred, more preferably 50% or more in terms of the voltage holding characteristics. 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. Depending on the method, a method of condensing and synthesizing is used.
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. Although the usage-amount of a dehydrating agent is based on the desired imidation rate, it is preferable to set it as 0.01-20 mol with respect to 1 mol of repeating units of a polyamic acid. 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-closing catalyst used is preferably 0.01 to 10 mol with respect to 1 mol 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 same 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. In addition, the imidized polymer can be purified by performing the same operation as the polyamic acid purification method on the reaction solution thus obtained.

[End-modified polymer]
The polyamic acid / imidized polymer of the present invention may be a terminal-modified type having a controlled molecular weight. By using this terminal-modified polymer, the coating characteristics of the liquid crystal aligning agent can be improved without impairing the effects of the present invention. Such a terminal-modified polymer can be synthesized by adding an acid monoanhydride, a monoamine compound, a monoisocyanate compound or the like to the reaction system when synthesizing a polyamic acid. 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 monoamine compounds include aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, and n-undecylamine. N-dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecylamine, n-octadecylamine, n-eicosylamine, etc. Can do. Examples of the monoisocyanate compound include phenyl isocyanate and naphthyl isocyanate.

[Logarithmic viscosity of polymer]
The polyamic acid and / or imidized polymer thus obtained has a logarithmic viscosity (η _ln ) value of preferably 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. ).

[Imidation rate of polymer]
The imidized polymer obtained as described above preferably has an imidation rate of 30 to 100%, more preferably 40 to 100%, and more preferably 50 to 100% from the viewpoint of improving voltage holding characteristics.
The imidation rate of the imidized polymer in the present invention is determined by ¹ H-NMR at room temperature using tetramethylsilane as a reference substance after drying the imidized polymer at 60 ° C. under reduced pressure and then dissolving it in deuterated dimethyl sulfoxide. Is obtained by the following equation (ii).
Imidization rate (%) = (1-A1 / A2 × α) × 100 −−−−−− (ii)
A1: Peak area derived from proton of NH group (10 ppm)
A2: Peak area derived from protons derived from aromatic rings (7 to 8 ppm)
α: Number ratio of protons derived from aromatic ring to one proton of NH group in polymer precursor (polyamic acid)

[Epoxy-containing compound]
Moreover, the liquid crystal aligning agent of this invention contains the specific epoxy compound represented by each of following formula (II-1) and (II-2).

(Wherein, a is an integer of 2 to 6, b is an integer of 1 to 4, R ^c is an organic group containing an a-valent aromatic ring, and R ^d is a b-valent aromatic ring. Is an organic group containing
Examples of the specific epoxy compound include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6 -Hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, N, N, -diglycidyl-benzyl Amine, N, N-diglycidyl-aminomethylcyclohexane, N, N, N ′, N′-tetraglycidyl-m-xylenediamine, N, N, N ′, N′- Tetraglycidyl-2,2′-dimethyl-4.4′-diaminobiphenyl, 2,2-bis [4- (N, N-diglycidyl-4-aminophenoxy) phenyl] propane, N, N, N ′, N '-Tetraglycidyl-4,4'-diaminodiphenylmethane, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, 1,4-bis (N, N-diglycidylaminomethyl) cyclohexane, 1,3 -Bis (N, N-diglycidylaminomethyl) benzene, N, N, N ', N'-tetraglycidyl-p-xylenediamine, the following formulas (III-1) and (III-2)

(Here, ^Re and ^Rf are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or a monovalent organic group having a fluorine atom having 1 to 20 carbon atoms.)
The epoxy-containing compound represented by each of these can be mentioned. Among these, particularly preferable specific epoxy compounds include epoxy-containing compounds represented by the above formula (III-1), such as benzene-1,4-diol diglycidyl ether, 2-methylbenzene-1,4-diol diene. Glycidyl ether, 2-ethylbenzene-1,4-diol diglycidyl ether, 2-n-hexylbenzene-1,4-diol diglycidyl ether, 2-n-dodecylbenzene-1,4-diol diglycidyl ether, 2- Epoxy-containing compounds such as trifluoromethylbenzene-1,4-diol diglycidyl ether and 2,5-diethylbenzene-1,4-diol diglycidyl ether;
And epoxy-containing compounds represented by the above formula (III-2), for example, N, N, N ′, N′-tetraglycidyl-p-phenylenediamine, N, N, N ′, N′-tetraglycidyl-2- Methyl-1,4-phenylenediamine, N, N, N ′, N′-tetraglycidyl-2-n-propyl-1,4-phenylenediamine, N, N, N ′, N′-tetraglycidyl-2- Dodecyl-4,4′-diaminobenzene, N, N, N ′, N′-tetraglycidyl-2-n-hexyl-1,4-phenylenediamine, N, N, N ′, N′-tetraglycidyl-2 -Trifluoromethyl-1,4-phenylenediamine, N, N, N ', N'-tetraglycidyl-2,5-dimethyl-1,4-phenylenediamine and 2,5-diethyl-1,4-phenylenediamine Epoxy such as Containing compound;
Is mentioned. Further, the content of the epoxy-containing compound is preferably 1 to 50 parts by weight, more preferably 5 to 45 parts by weight with respect to 100 parts by weight of the polymer.

[Amine compound]
The liquid crystal alignment agent of the present invention, within the range that does not impair the physical properties of interest, from the viewpoint of storage stability and electrical characteristics, the amine compound that contained.
Examples of such amine compounds include n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, n-undecylamine, and n-dodecylamine. , N-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecylamine, n-octadecylamine, n-eicosylamine, 2-methoxyethylamine, 2-methoxy Benzylamine, 4-methoxybenzylamine, diethylamine, diisopropylamine, methylethylamine, n-ethylcyclohexylamine, triethylamine, triethanolamine, amine compounds represented by the following formulas (VI-1) to (VI-3) ;

(Here, X ² represents a monovalent organic group, and a plurality of X ² present in each molecule may be the same or different.)
Amine compounds represented by the following formulas (VI-4) to (VI-5);

(Here, X ³ represents a divalent organic group, and a plurality of X ³ present in each molecule may be the same or different.)
And so on.

Examples of the amine compounds represented by the formulas (VI-1) to (VI-3) include aniline, o-toluidine, m-toluidine, p-toluidine, 2-ethylaniline, 3-ethylaniline, 4- Ethyl aniline, p-hexylaniline, 2-fluoroaniline, 4-fluoroaniline, 2,4,6-trifluoroaniline, o-phenetidine, m-phenetidine, p-phenetidine, p-trifluoromethoxyaniline, p-tri Examples include fluoroethoxyaniline, cyclohexylamine, and cyclooctylamine.
Examples of the amine compounds represented by the above formulas (VI-4) to (VI-5) include pyridine, piperidine, piperazine, 1-cyclohexylpiperazine 2-azabicyclo [2.2.2] octane, and 9-azabicyclo. [3.3.1] Nonane, 9-methyl-9-azabicyclo [3.3.1] nonane, 1,4-diazabicyclo [2.2.2] octane, 3,7-diazabicyclo [3.3.1]. Nonane and 1,8-diazabicyclo [5.4.0] undecene.

Among these, particularly preferred amine compounds are n-propylamine, n-butylamine, n-decylamine, n-hexylamine, 2-methoxybenzylamine, 4-methoxybenzylamine, diethylamine, diisopropylamine from the viewpoint of electrical characteristics. , Triethylamine, aniline, p-toluidine, p-ethylaniline, p-phenetidine, p-trifluoromethoxyaniline, p-trifluoroethoxyaniline, cyclohexylamine, 1,4-diazabicyclo [2.2.2] octane and 1 , 8-diazabicyclo [5.4.0] undecene. The content of the addition the amine compound is 0.1 to 20 parts by weight per 100 parts by weight of the polymer, preferably from 0.1 to 10 parts by weight.

  In addition, 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 that does not impair the intended 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- Aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl 1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-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, 3- (N-allyl-N-glycidyl) aminopropyltrimethoxysilane and 3- ( N, N-diglycidyl) aminopropyltrimethoxysila And the like.

[Vertical alignment type liquid crystal alignment agent]
In order to obtain the liquid crystal aligning agent of the present invention, the polyamic acid polymer and / or the imidized polymer, the epoxy-containing compound, the amine compound, and other compounds used as necessary are preferably an organic solvent. It is dissolved and contained. Moreover, 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.

  As an organic solvent which comprises the liquid crystal aligning agent of this invention, the solvent illustrated as what is used for the synthesis reaction of a polyamic acid can be mentioned, for example. Moreover, the poor solvent illustrated as what can be used together in the case of the synthesis reaction of a polyamic acid can also be selected suitably, and can be used together. Particularly preferable organic solvents used in the liquid crystal aligning agent of the present invention include, for example, N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N, N-dimethylformamide, N, N-dimethylacetamide, 4 -Hydroxy-4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n -Propyl ether, ethylene glycol-i-propyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol Examples thereof include coal dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate and diethylene glycol monoethyl ether acetate, isoamyl propionate, isoamyl isobutyrate, and diisopentyl ether. These can be used alone or in admixture of two or more.

The solid content concentration in the liquid crystal aligning agent of the present invention is selected in consideration of viscosity, volatility and the like. Preferably it is the range of 1-10 weight%. That is, the liquid crystal aligning agent of the present invention is applied to the substrate surface to form a resin film that becomes a liquid crystal aligning film. When the solid content concentration is less than 1% by weight, the film thickness of the resin film is It is difficult to obtain a good liquid crystal alignment film because it is too small, and when the solid content concentration exceeds 10% by weight, the film thickness of the resin film is too large to obtain a good liquid crystal alignment film, In addition, the viscosity of the liquid crystal aligning agent increases, resulting in poor coating properties. The particularly preferable solid content concentration range varies depending on the method used when the liquid crystal aligning agent is applied to the substrate. For example, in the case of the spinner method, the range is 1.5 to 4.5% by weight. In the case of the printing method, it is particularly preferable that the solid content concentration is in the range of 3 to 9% by weight, and thereby the solution viscosity is in the range of 12 to 50 mPa · s. When the ink jet method is used, it is particularly preferable that the solid content concentration is in the range of 1 to 5% by weight, and thereby the solution viscosity is in the range of 3 to 15 mPa · s.
The temperature at which the liquid crystal aligning agent of the present invention is prepared is preferably 0 ° C to 200 ° C, more preferably 20 ° C to 60 ° C.

[Production of display element using liquid crystal aligning agent]
The vertical alignment type liquid crystal display element using the vertical alignment type liquid crystal aligning agent of the present invention can be produced, for example, by the following method.

(1) The liquid crystal aligning agent of the present invention is applied to one surface of a substrate on which a patterned transparent conductive film is provided by, for example, a roll coater method, a spinner method, a printing method, an ink jet method, etc. A coating film is formed by heating the surface. Here, as the substrate, for example, glass such as float glass or soda glass; a transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, alicyclic polyolefin, or the like can be used. As a transparent conductive film provided on one surface of the substrate, an NESA film (registered trademark of PPG, USA) made of tin oxide (SnO ₂ ), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ), etc. Can be used. For patterning these transparent conductive films, a photo-etching method or a method using a mask in advance is used. In applying the liquid crystal aligning agent, for example, a functional silane-containing compound or a functional titanium-containing compound can be applied in advance in order to further improve the adhesion between the substrate surface and the resin film. For the purpose of preventing dripping of the alignment agent applied after application of the liquid crystal alignment agent, preheating (pre-baking) is preferably performed. The pre-baking temperature is preferably 30 to 200 ° C, more preferably 40 to 150 ° C, and particularly preferably 40 to 100 ° C. Thereafter, a baking (post-baking) step is performed for the purpose of completely removing the solvent and heat imidizing the polyamic acid. The firing (post-bake) temperature is preferably 80 to 300 ° C, more preferably 120 to 250 ° C. In this way, the liquid crystal aligning agent of the present invention containing a polyamic acid forms a coating film that becomes a liquid crystal aligning film by removing the organic solvent after coating, and further proceeds with dehydration ring closure by further heating. An imidized liquid crystal alignment film can also be used. The film thickness of the formed resin film is preferably 0.001 to 1 μm, more preferably 0.005 to 0.5 μm.

(2) Two substrates on which the vertical liquid crystal alignment film is formed as described above are manufactured, the two substrates are arranged to face each other with a gap (cell gap) therebetween, and the peripheral portions of the two substrates are sealed. A liquid crystal cell is formed by laminating using an agent, injecting and filling liquid crystal into the cell gap defined by the substrate surface and the sealing agent, and sealing the injection hole. And a liquid crystal display element is obtained by arrange | positioning a polarizing plate to the outer surface of a liquid crystal cell, ie, the transparent substrate side which comprises a liquid crystal cell.
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, biphenyl cyclohexane liquid crystal, pyrimidine liquid crystal, dioxane liquid crystal, bicyclooctane. Type liquid crystal, cubane type liquid crystal 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.

(3) In order to evaluate vertical alignment, the vertical alignment type liquid crystal alignment film formed in (1) above is fixed in a certain direction with a roll wound with a cloth made of fibers such as nylon, rayon, and cotton. After the rubbing rubbing process, a liquid crystal display element is formed. The rubbing treatment has an effect of disturbing the vertical alignment of the surface. Therefore, when the pretilt angle of the liquid crystal display element after rubbing is measured, the higher the pretilt angle closer to the original 90 °, the better the vertical alignment. I think that.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.
Various measurements in Examples and Comparative Examples were performed by the following methods.

(1) Measurement of voltage holding ratio After applying a voltage of 5 V to a liquid crystal display element at 60 ° C. for 60 microseconds with a span of 16.7 microseconds, voltage holding after 16.7 milliseconds from the release of application The rate was measured.
(2) Evaluation of afterimage by luminance Two sets of liquid crystal display elements are prepared, one of which is applied with a DC voltage of 1 V (element A) and the other with a DC voltage of 5 V (element B) applied at room temperature for 2 hours. After that, when the luminances of the element A and the element B observed at the DC voltage of 2.5 V are expressed in 256 gradations, those having a luminance difference of 15 or less were defined as “good afterimage”.
(3) Evaluation of Vertical Alignment When a pretilt angle is measured by a crystal rotation angle method for a rubbing-processed vertical alignment liquid crystal display device manufactured by the above method, a vertical alignment property “ “Good” and less than 86 ° were regarded as “poor” in the vertical alignment.
(4) Evaluation of printability Viscosity of 12 to 25 mPa · sec (solid content concentration 6.0 wt% to 8.0 wt%), γ-butyrolactone: N-methyl-2-pyrrolidone: After coating and baking by a printing method using a vertical alignment type liquid crystal aligning agent prepared so that butyl cellosolve = 40: 30: 30 (weight ratio), the coating film was visually observed. A coating film having no repellency or coating unevenness was defined as “good”.
(5) Imidation rate measurement method of imidized polymer After imidized polymer was dried under reduced pressure at room temperature, it was dissolved in deuterated dimethyl sulfoxide, and 1H-NMR was measured at room temperature using tetramethylsilane as a reference substance. It calculated | required by the formula shown by following formula (ii).
Imidation ratio (%) = (1-A ¹ / A ² × α) × 100 ------ (i)
A ¹ : NH group proton-derived peak area (10 ppm)
A ² : Peak area derived from other protons α: Number ratio of other protons to one proton of NH group in polymer precursor (polyamic acid) (6) Solution viscosity Solution viscosity of polymer (mPa · s) ) Was measured at 25 ° C. using an E-type rotational viscometer for a solution diluted to a predetermined solid content concentration using a predetermined solvent.

Synthesis Examples 1 to 21
To N-methyl-2-pyrrolidone, a diamine and tetracarboxylic dianhydride (shown as “acid anhydride” in the table) in the order shown in Table 1 were added in this order to obtain a solution having a solid content concentration of 20% by weight. And a reaction at 60 ° C. for 4 hours to obtain a polyamic acid polymer. 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 is reprecipitated with diethyl ether, and then recovered and dried under reduced pressure, so that it is an imidized polymer having the solution viscosity and imidization ratio shown in Table 1 (A-1) to (A-21). Got.

In Table 1, for diamine compounds and acid anhydrides, the numbers in parentheses indicate the content ratio (molar ratio), and the meanings of the symbols in the table are as follows.

<Diamine compound>
D-1: Diamine represented by Formula (13) D-2: Diamine represented by Formula (16) D-3: Diamine represented by Formula (17) D-4: Formula (20) D-5: 1,4-bis (aminomethyl) -bicyclo [2.2.1] heptane D-6: 1,3-bis (aminomethyl) cyclohexane D-7: metaxylenediamine D-8: 3,3 ′-(tetramethyldisiloxane-1,3-diyl) bis (propylamine)
D-9: p-phenylenediamine D-10: 4,4′-diaminodiphenylmethane D-11: 2,2′-dimethyl-4,4′-diaminobiphenyl <tetracarboxylic dianhydride>
T-1: 2,3,5-tricarboxycyclopentyl acetic acid dianhydride T-2: 1,3,3a, 4,5,9b-hexahydro-8-methyl-5 (tetrahydro-2,5-dioxo-3 -Furanyl) -naphtho [1,2-c] -furan-1,3-dione T-3: 1,2,3,4-cyclobutanetetracarboxylic dianhydride

Example 1
The imidized polymer (A-1) obtained in Synthesis Example 1 was dissolved in a γ-butyrolactone / N-methyl-2-pyrrolidone / butyl cellosolve mixed solution (weight ratio 40/30/30) to obtain benzene-1. , 4-diol diglycidyl ether (epoxy A) and n-propylamine (amine A) were dissolved in 20 parts by weight and 2 parts by weight, respectively, with respect to 100 parts by weight of the polymer, and the solid content concentration was 6.5% by weight. It was set as the solution. When this solution was visually observed, it was a clear solution without turbidity. Subsequently, filtration was performed using a filter having a pore size of 0.2 μm to prepare the film forming composition of the present invention, and then evaluation of printability was performed. It was confirmed that it has sex.
Next, a film forming composition of the present invention was prepared in the same manner as described above except that the solid content concentration was 4% by weight.
Next, the film-forming composition is applied by a spinner onto a transparent conductive film made of an ITO film provided on one surface of a glass substrate having a thickness of 1 mm, and dried at 200 ° C. for 60 minutes. A 0.08 μm film was formed.

Next, after applying an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 3.5 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 through the liquid crystal injection port, and then the liquid crystal injection port is sealed with an acrylic photocuring adhesive, and polarizing plates are formed on both sides of the substrate. Were laminated to prepare a liquid crystal display element. With respect to the obtained liquid crystal display element, the voltage holding ratio was measured and found to be 99% or more, indicating good voltage holding characteristics. Further, afterimage evaluation by luminance was performed, the luminance difference was 12, and good afterimage characteristics were exhibited. The results are summarized in Table 3.
Next, with respect to the liquid crystal alignment film coated substrate of a pair of transparent electrodes / transparent electrode substrates, a rubbing machine having a roll around which a rayon cloth is wound, a roll rotation speed of 400 rpm, a stage moving speed of 3 cm / second, and a hair foot indentation length. A liquid crystal display element for vertical alignment evaluation was prepared in the same manner as described above except that a rubbing treatment was performed at 0.4 mm, ultrasonic cleaning was performed in ultrapure water for 1 minute, and drying was performed in a clean oven at 100 ° C. for 10 minutes. Produced. When the obtained liquid crystal display element was evaluated for vertical alignment, a good vertical alignment of 87.0 ° was obtained. The results are summarized in Table 5.

Examples 2-61, Comparative Examples 1-4
In accordance with the formulations shown in Tables 2 and 3 below, a film-forming composition having a solid content concentration of 6.5% was prepared in the same manner as in Example 1, and the printability was evaluated. Similarly, a film-forming composition having a solid content concentration of 4% was prepared to produce a liquid crystal display device. And the afterimage evaluation by voltage holding rate and a brightness | luminance and vertical orientation evaluation were implemented. The results are shown in Tables 2 and 3.

In Tables 2 and 3, in the epoxy-containing compounds, the numbers in parentheses indicate the content parts by weight with respect to 100 parts by weight of the polymer, and the meanings of the symbols in the tables are as follows.

<Epoxy-containing compound>
Epoxy A: benzene-1,4-diol diglycidyl ether epoxy B: 2-n-dodecylbenzene-1,4-diol diglycidyl ether epoxy C: N, N, N ′, N′-tetraglycidyl-p-phenylene Diamine epoxy D: N, N, N ′, N′-tetraglycidyl-2-dodecyl-4,4′-diaminobenzene In Tables 2 and 3, the numbers in parentheses are 100 parts by weight of the polymer. The content parts by weight are shown below, and the meanings of the symbols in the table are as follows.

<Amine compound>
Amine A: n-propylamineamine B: 4-methoxybenzylamine,
Amine C: p-ethylanilineamine D: p-phenetidineamine E: p-trifluoromethoxyanilineamine F: 1,8-diazabicyclo [5.4.0] undecene

Claims (5)

It consists of an imide repeating unit represented by the following formula (I-2) and optionally an amic acid repeating unit represented by the following formula (I-1), and the imide repeating unit is 30 mol% or more based on the total thereof. And at least one epoxy selected from the group consisting of compounds containing at least two epoxy groups in the molecule represented by each of the following formulas (II-1) and (II-2) mixing and containing compound 1 to 50 parts by weight, and formula (VI-1) ~ (VI -5) at least one amine compound selected from the group that consisting of compounds represented by each 0.1 to 20 parts by weight A vertical alignment type liquid crystal aligning agent prepared by

(Here, P ¹ represents a tetravalent organic group derived from tetracarboxylic dianhydride and Q ¹ represents a divalent organic group derived from diamine.)

(Here, P ² represents a tetravalent organic group derived from tetracarboxylic dianhydride and Q ² represents a divalent organic group derived from diamine.)

(Here, a is an integer of 2 to 6, b is an integer of 1 to 4, R ^c is an organic group containing an a-valent aromatic ring, and R ^d contains a b-valent aromatic ring. It is an organic group.)

(Here, X ² represents a monovalent organic group, X ³ represents a divalent organic group, and a plurality of X ² and X ³ present in each molecule may be the same or different. ) The vertical alignment liquid crystal aligning agent according to claim 1, wherein the epoxy compound is at least one selected from the group consisting of epoxy-containing compounds represented by the following formulas (III-1) and (III-2).

(Here, ^Re and ^Rf are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or a monovalent organic group having a fluorine atom having 1 to 20 carbon atoms.) At least one part of Q ^{1 in} the above formula (I-1) and at least one part of Q ^{2 in} the above formula (I-2) are represented by the following formulas (IV-1) and (IV-2), respectively. The vertical alignment type liquid crystal aligning agent according to claim 1 or 2, which is at least one selected from the group consisting of divalent organic groups.

(Where X ¹ is a single bond, —O—, —CO—, —COO—, —OCO—, —NHCO—, —CONH—, —S—, a methylene group, or an alkylene group having 2 to 6 carbon atoms. Or a phenylene group, and R ¹ is a monovalent organic group having an alkyl group having 10 to 20 carbon atoms, an alicyclic skeleton having 4 to 40 carbon atoms, or a monovalent organic group having a fluorine atom having 6 to 20 carbon atoms. R ² is an organic group, and R ² is a divalent organic group having an alicyclic skeleton having 4 to 40 carbon atoms or a divalent organic group having a fluorine atom having 5 to 30 carbon atoms. ) A plurality of X ¹ present therein may be the same or different. P ¹ in the above formula (I-1) and P ² in the above formula (I-2) are each composed of a tetravalent organic group represented by each of the following formulas (V-1) and (V-2). vertical alignment liquid crystal aligning agent according to claim 1, containing 50 mol% or more of the at least one selected from the group, the total tetravalent organic group ^(P 1 ⁺ P ^2).

(Here, R ³ represents a hydrogen atom or a monovalent organic group.) A vertical alignment liquid crystal display element comprising a vertical alignment liquid crystal alignment film formed from the vertical alignment liquid crystal aligning agent according to claim 1.