JP2008299318A - Vertical alignment type liquid crystal aligning agent and liquid crystal display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal aligning agent which has satisfactory printing properties and can form a liquid crystal alignment layer having excellent vertical alignment property and reliability, and to provide a liquid crystal display element having the liquid crystal alignment layer obtained by the agent. <P>SOLUTION: The vertical alignment type liquid crystal aligning agent contains a polymer and a specified epoxy compound. The polymer comprises recurring units each represented by formula (I-1) or formula (I-2) and obtained by reaction of a tetra carboxylic dianhydride and a diamine compound and contains a recurring unit having a divalent organic group. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vertical alignment liquid crystal aligning agent and a liquid crystal display device, and more specifically, a vertical alignment liquid crystal aligning agent excellent in printability, vertical alignment and reliability, and a liquid crystal aligning agent obtained from the vertical alignment liquid crystal aligning agent. The present invention relates to a liquid crystal display element.

Conventionally, as a liquid crystal display element, a liquid crystal alignment film is formed on the surface of a substrate provided with a transparent conductive film to form a liquid crystal display element substrate. A cell having a sandwich structure is formed by forming an anisotropic nematic liquid crystal layer, and the major axis of the liquid crystal molecule is continuously twisted from 0 to 360 degrees from one substrate to the other substrate. There are known liquid crystal display elements having liquid crystal cells such as TN (Twisted Nematic) type, STN (Super Twisted Nematic) type, and IPS (In Plane Switching) type. (See Patent Document 1 and Patent Document 2).
In such a liquid crystal cell, the liquid crystal alignment film is usually formed by a method (rubbing method) in which the surface of the organic film formed on the surface of the substrate is rubbed in one direction with a cloth material such as rayon. As such an organic film, those made of a polyimide resin obtained by polycondensation reaction of a diamine compound and a dianhydride are widely used from the viewpoint of heat resistance and electrical characteristics.

By the way, in a liquid crystal cell of TN (Twisted Nematic) type, STN (Super Twisted Nematic) type or the like, the liquid crystal alignment film tilts the liquid crystal molecules at a predetermined angle (usually 3 to 10 °) with respect to the substrate surface. It is necessary to have a pretilt angle characteristic. Here, the “pretilt angle” in this specification represents an angle of inclination of liquid crystal molecules from a direction parallel to the substrate surface.
In addition, as an operation mode of a liquid crystal display element different from the above, a vertical (homeotropic) alignment mode in which liquid crystal molecules having negative dielectric anisotropy are aligned perpendicular to the substrate, that is, at a pretilt angle of about 90 °, is also known. ing. In this operation mode, when a voltage is applied between the substrates, the liquid crystal molecules are inclined from the normal direction of the substrate toward one direction in the substrate surface.
In order to develop a high pretilt angle required in such various modes, it is known that a polyimide resin having a bulky substituent such as an octadecyl group may be used as the liquid crystal alignment film. Among such substituents, those having a bulky and rigid steroid skeleton are particularly useful in order to develop a high pretilt angle. A polyimide resin having such a bulky substituent can be obtained by using a diamine compound or dianhydride having a bulky substituent during the synthesis.
In recent years, liquid crystal display elements have been used under all conditions and environments. For this reason, reliability has been regarded as one of the characteristics required for liquid crystal alignment agents.

JP 56-91277 A JP-A-1-120528 JP-A-4-281427 JP 2004-331937 A JP 2006-010896 A

An object of the present invention is to provide a vertical alignment type liquid crystal aligning agent capable of forming a liquid crystal alignment film having good printability and excellent in vertical alignment and reliability.
Another object of the present invention is to provide a liquid crystal display device comprising a liquid crystal alignment film obtained from the vertical alignment liquid crystal aligning agent.

The vertical alignment type liquid crystal aligning agent of this invention is a repeating unit represented by each of following formula (I-1) and following formula (I-2) obtained by reaction of tetracarboxylic dianhydride and a diamine compound. Q ¹ in the following formula (I-1) and Q ² in the following formula (I-2) as at least one repeating unit selected from the group consisting of the following formulas (II-1) and ( A polymer containing a repeating unit having at least one of the divalent organic groups represented by each of II-2), and
It contains an epoxy compound represented by the following formula (III).

(In Formula (I-1), P ¹ is a tetravalent organic group derived from tetracarboxylic acid, and Q ¹ is a divalent organic group derived from a diamine compound. Also, Formula (I-1) P ² is a tetravalent organic group derived from tetracarboxylic acid, and Q ² is a divalent organic group derived from a diamine compound.)

(In the formula (II-1), X ¹ is a single bond, —O—, —CO—, —COO—, —OCO—, —NHCO—, —CONH—, —S—, a methylene group, 2 carbon atoms. An alkylene group having 6 to 6 carbon atoms or a phenylene group, and R ¹ is an alkyl group having 10 to 20 carbon atoms, a monovalent organic group having an alicyclic skeleton having 4 to 40 carbon atoms, or a fluorine atom having 6 to 20 carbon atoms. In Formula (II-2), X ¹ is a single bond, —O—, —CO—, —COO—, —OCO—, —NHCO—, —CONH—. , —S—, a methylene group, an alkylene group having 2 to 6 carbon atoms, or a phenylene group, and R ² is a divalent organic group having an alicyclic skeleton having 4 to 40 carbon atoms or a group having 5 to 30 carbon atoms. (It is a divalent organic group having a fluorine atom.)

(In the formula (III), a is an integer of 2 to 4, R ³ is an a-valent organic group, and the bonding sites for a N are aliphatic carbons.)

According to the liquid crystal aligning agent which concerns on this invention, while being able to obtain favorable printability, the liquid crystal aligning film excellent in vertical alignment property and reliability can be formed.
The liquid crystal display element according to the present invention can be effectively used in various devices, and is suitable as a display device for a desktop computer, wristwatch, table clock, mobile phone, counting display board, word processor, personal computer, liquid crystal television, and the like. Can be used.

Hereinafter, the present invention will be described in detail.
The vertical alignment type liquid crystal aligning agent (hereinafter also referred to as “liquid crystal aligning agent”) according to the present invention is obtained by reacting tetracarboxylic dianhydride with a diamine compound, the above formula (I-1) or formula ( It consists of a polymer composed of repeating units represented by I-2) and an epoxy compound represented by the above formula (III).
Among the above repeating units, a polymer containing a repeating unit represented by the above formula (I-1) (hereinafter also referred to as “specific polyamic acid polymer”) is usually tetracarboxylic dianhydride and It is obtained by reacting a diamine compound with an organic solvent. In addition, the polymer containing the repeating unit represented by the above formula (I-2) (hereinafter, also referred to as “specific polyimide polymer”) has a dehydrating ring closure at the amic acid portion of the specific polyamic acid polymer. It is obtained by doing.
Hereinafter, the specific polyamic acid polymer which comprises the liquid crystal aligning agent which concerns on this invention, and the manufacturing method of a specific polyimide polymer are demonstrated.

[Tetracarboxylic dianhydride]
Examples of the tetracarboxylic dianhydride that can be used to obtain the specific polyamic acid polymer and / or the specific polyimide polymer constituting the liquid crystal aligning agent according to the present invention include, for example, butanetetracarboxylic dianhydride 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 Acid dianhydride, 1,3-dichloro-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobut Tetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3 ′, 4,4 ′ -Dicyclohexyltetracarboxylic 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 ^2,5 . 1 ^7,10 ] dodecane-3,4,8,9-tetracarboxylic dianhydride, 2,3,4,5-tetrahydrofuran tetracarboxylic 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 (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, 5 (2,5-dioxotetrahydrofural) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 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, represented by the following formulas (1) and (2) Aliphatic and alicyclic tetracarboxylic dianhydrides such as compounds such as pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4 '-Biphenylsulfonetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic 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-furantetra Carboxylic dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenylsulfone dianhydride, 4, 4'-bis (3,4-dicarboxyphenoxy) diphenylpropane dianhydride, 3,3 ', 4,4'-perfluoroisopropylidenediphthalic dianhydride, 3,3', 4,4'- Biphenyltetracarboxylic dianhydride, bis (phthalic acid) phenylphosphine oxide dianhydride, ethylene glycol-bis (anhydrotrimellitate), propylene glycol-bis (anhy Rotrimellitate), 1,4-butanediol-bis (anhydrotrimellitate), 1,6-hexanediol-bis (anhydrotrimellitate), 1,8-octanediol-bis (anhydrotrimellitate) , 2,2-bis (4-hydroxyphenyl) propane-bis (anhydrotrimellitate), aromatic tetracarboxylic dianhydrides such as compounds represented by the following formulas (3) to (6) Can do. These may be used alone or in combination of two or more.

(Wherein R ¹¹ and R ¹² represent a divalent organic group having an aromatic ring, R ⁴ and R ⁵ represent a hydrogen atom or an alkyl group, and a plurality of R ⁴ and R ⁵ are the same. But it may be different.)

  Of these, 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, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutane Tetracarboxylic dianhydride, bicyclo [2.2.1] heptane-2,3,5,6-tetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1 , 2,4,5-Cyclohe Santetracarboxylic 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 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1, 3-dione, 1,3,3a, 4,5,9b-hexahydride -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-tricarboxycyclopentylacetic acid At least one tetracar selected from anhydrides The boric acid dianhydride is preferably contained in an amount of 50 mol% or more based on the total tetracarboxylic dianhydride, and more preferably 70 mol% or more from the viewpoint of improving characteristics.

[Diamine compound]
Q ¹ and Q ² in the repeating units represented by the above formula (I-1) and the above formula (I-2) are organic groups derived from the diamine compound, and the residue obtained by removing two amino groups from the diamine compound. Corresponds to the group. In the present invention, as Q ¹ and Q ² , a repeating unit having at least one of the organic groups represented by the above formula (II-1) and the above formula (II-2) (hereinafter referred to as “specific repeating unit”). A polymer containing) is used.

In the above formula (II-1), R ¹ has an alkyl group having 10 to 20 carbon atoms, a monovalent organic group having an alicyclic skeleton having 4 to 40 carbon atoms, or a fluorine atom having 6 to 20 carbon atoms. It is a monovalent organic group.
Here, examples of the alkyl group having 10 to 20 carbon atoms include an n-decyl group, an n-dodecyl group, an n-pentadecyl group, an n-hexadecyl group, an n-octadecyl group, and an n-eicosyl group.
Examples of the monovalent organic group having an alicyclic skeleton having 4 to 40 carbon atoms include cycloaliphatic skeletons derived from cycloalkanes such as cyclobutane, cyclopentane, cyclohexane, and cyclodecane; And monovalent organic groups having a cyclic skeleton; a steroid skeleton such as cholesterol and cholestanol. The monovalent organic group having the alicyclic skeleton may be a group substituted with a halogen atom, preferably a fluorine atom.
Examples of the monovalent organic group having a fluorine atom having 6 to 20 carbon atoms include linear alkyl groups having 6 to 20 carbon atoms such as n-hexyl group, n-octyl group and n-decyl group; A part or all of hydrogen atoms in an organic group such as an alicyclic hydrocarbon group having 6 to 20 carbon atoms such as a group or a cyclooctyl group; an aromatic hydrocarbon group having 6 to 20 carbon atoms such as a phenyl group or a biphenyl group Are substituted with a fluorine atom, a fluoroalkyl group or a fluoroalkyloxy group.

In the formula (II-1), the group represented by X ¹ is a single bond, —O—, —CO—, —COO—, —OCO—, —NHCO—, —CONH—, —S—, A methylene group, an alkylene group having 2 to 6 carbon atoms, and a phenylene group, and among these, particularly preferred are groups represented by -O-, -CO-, -COO-, and -OCO-.

  Specific examples of the diamine compound having a group represented by the above formula (II-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 (7) to (22).

In the above formula (II-2), 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.
Here, examples of the divalent organic group having an alicyclic skeleton having 4 to 40 carbon atoms include alicyclic skeletons derived from cycloalkanes such as cyclobutane, cyclopentane, cyclohexane, and cyclodecane; and bridges such as norbornene and adamantane. An alicyclic skeleton; a divalent organic group having a steroid skeleton such as cholesterol and cholestanol. The divalent organic group having the alicyclic skeleton may be a group substituted with a halogen atom, preferably a fluorine atom.
Specific examples of the divalent organic group having a fluorine atom having 5 to 30 carbon atoms include linear alkyl groups having 5 to 30 carbon atoms such as n-hexyl group, n-octyl group and n-decyl group. A part of hydrogen atoms in an organic group such as an alicyclic hydrocarbon group having 5 to 30 carbon atoms such as a cyclohexyl group or a cyclooctyl group; an aromatic hydrocarbon group having 5 to 30 carbon atoms such as a phenyl group or a biphenyl group; Or the group which substituted all with the fluorine atom or the fluoroalkyl group is mentioned. Specific examples of the diamine compound having a group represented by the above formula (II-2) include compounds represented by the following formulas (23) to (27).

  In the specific polyamic acid polymer and / or the specific polyimide polymer used in the present invention, the ratio of the specific repeating unit is preferably 7 mol% or more in all repeating units from the viewpoint of vertical alignment, More preferably, it is 10 mol% or more.

In the synthesis of the specific polyamic acid polymer and / or the specific polyimide polymer used in the present invention, Q ¹ and Q ² are represented by the above formula (II-1) or the above as long as the effects of the present invention are not impaired. A repeating unit having a group other than the divalent organic group represented by the formula (II-2) (hereinafter referred to as “other repeating unit”) may be contained.

Examples of the diamine compound for obtaining other repeating units include p-phenylenediamine, 2-methyl-1,4-phenylenediamine, 2-ethyl-1,4-phenylenediamine, 2,5-dimethyl-1, and the like. 4-phenylenediamine, 2,5-diethyl-1,4-phenylenediamine, 2,3,5,6-tetramethyl-1,4-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane, 4 , 4'-diaminodiphenylethane, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-di (trifluoro Methyl) -4,4'-diaminobiphenyl, 2,2'-diethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4 ' Diaminobiphenyl, 3,3′-di (trifluoromethyl) -4,4′-diaminobiphenyl, 3,3′-diethyl-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) pheny [Ru] hexafluoropropane, 2,2-bis (4-aminophenyl) propane, 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-amino) Phenyl) -10-hydroanthracene, 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, '-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) Aromatic diamines such as phenoxy] -octafluorobiphenyl, 4- (4-n-heptylcyclohexyl) phenoxy-2,4-diaminobenzene;
1,3-bis (aminomethyl) benzene, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, 4,4-diaminoheptamethylenediamine Aliphatic diamines such as

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 A diamine having:
Examples thereof include compounds represented by the following formulas (28) to (30).
These diamine compounds can be used alone or in combination of two or more.

(Wherein R ⁶ represents a hydrocarbon group having 1 to 12 carbon atoms, a plurality of R ⁶ may be the same or different, p is an integer of 1 to 3, and q is 1 to 20) And y is an integer of 2 to 12, and z is an integer of 1 to 5.)

  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, 2,2′-dimethyl-4,4′-diaminobiphenyl, 2, 2′-di (trifluoromethyl) -4,4′-diaminobiphenyl, 2,2′-diethyl-4,4′-diaminobiphenyl, 3,3′-dimethyl-4,4′-diaminobiphenyl, 3, 3′-diethyl-4,4′-diaminobiphenyl, 3,3′-di (trifluoromethyl) -4,4′-diaminobiphenyl, 4,4′-diaminodiphenyl ester Ter, 4,4'-diaminobenzophenone, 2,2-bis (4-aminophenyl) propane, 2,2-bis (4-aminophenyl) hexafluoropropane, 2,6-diaminopyridine, 3,4-diamino Pyridine and the like can be mentioned as preferred examples.

[Synthesis of specific polyamic acid polymer]
The ratio of the tetracarboxylic dianhydride and the diamine compound used for the synthesis reaction of the specific polyamic acid polymer is such that the acid anhydride group of the tetracarboxylic dianhydride is equivalent to 1 equivalent of the amino group of the diamine compound. Is preferably a ratio of 0.2 to 2.0 equivalents, more preferably 0.8 to 1.2 equivalents.
The synthesis reaction of the specific polyamic acid polymer is usually performed in an organic solvent under a temperature condition of -20 ° C to 150 ° C, preferably 0 to 100 ° C.

Here, the organic solvent is not particularly limited as long as it can dissolve a specific polyamic acid polymer to be synthesized, and specific examples thereof include 1-methyl-2-pyrrolidone, N, N- Aprotic polar solvents such as dimethylacetamide, N, N-dimethylformamide, dimethylsulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide; phenolic solvents such as m-cresol, xylenol, phenol, halogenated phenol And so on.
The amount of organic solvent used (α) is usually such that the total amount (β) of tetracarboxylic dianhydride and diamine compound is 0.1 to 30% by weight with respect to the total amount (α + β) of the reaction solution. It is preferable that

  In addition, the organic solvent includes a specific polyamic acid polymer that generates an alcohol, a ketone, an ester, an ether, a halogenated hydrocarbon, a hydrocarbon, or the like, which is a poor solvent for the specific polyamic acid polymer. They can be used in combination as long as no coal is precipitated. Specific examples of such poor solvents include 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, malonic 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, Examples thereof include 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 a specific polyamic acid polymer is obtained. Then, the reaction solution is poured into a large amount of 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 thereby generate a specific polymer polyamic acid. Can be obtained. Also, the specific polyamic acid polymer is purified again by dissolving the specific polyamic acid polymer again in an organic solvent and then precipitating with a poor solvent or depressurizingly distilling with an evaporator once or several times. be able to.

[Synthesis of specific polyimide polymer]
The specific polyimide polymer constituting the liquid crystal aligning agent of the present invention can be synthesized by dehydrating and ring-closing a specific polyamic acid polymer. The specific polyimide 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 polyimide. The imidation ratio of the specific polyamic acid polymer and / or specific polyimide polymer used in the present invention is preferably 40% or more. Dehydration and ring closure of a specific polyamic acid polymer may be performed by (i) a method of heating the specific polyamic acid polymer or (ii) dissolving the specific polyamic acid polymer in an organic solvent. A method of condensing and synthesizing by a method of adding a dehydration ring closure catalyst and heating as necessary is used.
The reaction temperature in the method of heating the specific polyamic acid polymer (i) above 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 resulting polyimide may decrease.
On the other hand, in the method of adding a dehydrating agent and a dehydrating ring closure catalyst to the solution of the specific polyamic acid polymer (ii) above, examples of the dehydrating agent include acid anhydrides such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride. Can be used. 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 specific polyamic acid polymer. 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 dehydrating agent and dehydrating ring-closing catalyst used is increased. 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 specific polyamic acid polymer 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, a specific polyimide polymer can be refine | purified by performing operation similar to the purification method of a specific polyamic acid polymer with respect to the reaction solution obtained in this way.

[End-modified polymer]
The specific polyamic acid polymer and specific polyimide polymer used in the present invention may be of a terminal-modified type having a controlled molecular weight. By using this terminal-modified polymer, the coating properties 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 a specific polyamic acid polymer is synthesized. 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.

[Solution viscosity]
The polymer used in the liquid crystal aligning agent according to the present invention preferably has a viscosity of 20 to 800 mPa · s, and has a viscosity of 30 to 500 mPa · s, when a 10% by weight solution is obtained. It is more preferable that
Here, the solution viscosity (mPa · s) of the polymer refers to a solution measured at 25 ° C. using an E-type viscometer for a solution diluted to a solid content concentration of 10% by weight using a predetermined solvent.

[Imidation rate of polymer]
The specific polyimide polymer obtained as described above preferably has an imidation ratio of 40% or more from the viewpoint of improving voltage holding characteristics.
The value of the imidization ratio of the specific polyimide polymer used in the present invention is determined by performing ¹ H-NMR at room temperature using tetramethylsilane as a reference substance after polyimide is dried at room temperature under reduced pressure and then dissolved in deuterated dimethyl sulfoxide. It is measured and obtained by the formula shown by the following formula (i).
Formula (i) Imidation ratio (%) = (1−A1 / A2 × α) × 100
Here, A1 is an NH group proton-derived peak area (10 ppm), A2 is an aromatic ring-derived proton-derived peak area (7 to 8 ppm), and α is a polymer precursor (specific polyamic acid polymer). , The ratio of the number of protons derived from the aromatic ring to one proton of the NH group.

[Vertical alignment type liquid crystal alignment agent]
In order to obtain the liquid crystal aligning agent of this invention, a specific polyamic acid polymer and / or a specific polyimide polymer are preferably comprised by being dissolved in an organic solvent. 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.
Examples of the organic solvent used in the liquid crystal aligning agent of the present invention include N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N, N-dimethylformamide, N, N-dimethylacetamide, 4-hydroxy- 4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene Glycol-i-propyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl Examples include ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, and diethylene glycol monoethyl ether acetate. Among these, a preferable solvent composition is a composition obtained by combining the above-mentioned solvents so that no polymer is precipitated in the aligning agent, and the surface tension of the aligning agent is in the range of 30 to 40 mN / m. Composition.

  The solid 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 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 If the solid content concentration exceeds 10% by weight, the resin film becomes too thick to obtain a good liquid crystal alignment film. In addition, the viscosity of the liquid crystal aligning agent increases, resulting in poor coating characteristics. 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, when the spinner method is used, the range of 1.5 to 4.5% by weight is particularly preferable. In the case of the printing method, it is particularly preferable that the solid content concentration is in the range of 4 to 10% by weight, and thereby the solution viscosity is in the range of 10 to 50 mPa · s. In the case of the ink jet method, it is particularly preferable that the solid content concentration is in the range of 2 to 5% by weight, and thereby the solution viscosity is in the range of 5 to 15 mPa · s.

Examples of the epoxy compound represented by the above formula (III) constituting the liquid crystal aligning agent according to the present invention (hereinafter referred to as “specific epoxy compound”) include N, N, N ′, N′-tetra. Glycidyl-1,2-diaminocyclohexane, N, N, N ′, N′-tetraglycidyl-1,3-diaminocyclohexane, N, N, N ′, N′-tetraglycidyl-1,4-diaminocyclohexane, bis (N, N-diglycidyl-4-aminocyclohexyl) methane, bis (N, N-diglycidyl-2-methyl-4-aminocyclohexyl) methane, bis (N, N-diglycidyl-3-methyl-4-aminocyclohexyl) Methane, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, 1,4-bis (N, N-diglycidylaminomethyl) cyclohexa 1,3-bis (N, N-diglycidylaminomethyl) benzene, 1,4-bis (N, N-diglycidylaminomethyl) benzene, 1,3,5-tris (N, N-diglycidyl) Examples include aminomethyl) cyclohexane, 1,3,5-tris (N, N-diglycidylaminomethyl) benzene, and compounds represented by the following formulas (31) to (35).
The content of the epoxy compound is preferably 1 to 50% by weight, more preferably 5 to 45% by weight in the solid content of the liquid crystal aligning agent from the viewpoint of reliability.

  In the liquid crystal aligning agent which concerns on this invention, epoxy compounds other than a specific epoxy compound (henceforth "other epoxy compounds") can be used together to such an extent that the effect of this invention is not impaired. Examples of other 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, 1,6- Hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, N, N, N ′, N ′ -Tetraglycidyl-p-phenylenediamine, N, N, N ', N'-tetraglycidyl-m-phenylenediamine, N, N, N', N'-tetraglycidyl-4, 4'- Aminodiphenylmethane, N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenyl ether, N, N, N ′, N′-tetraglycidyl-2,2′-dimethyl-4,4′-diamino Biphenyl and the like can be mentioned as preferable ones.

  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, 3- ( N, N-diglycidyl) aminopropyltrimethoxysilane It can be mentioned.

[Production of display element using liquid crystal aligning agent]
The liquid crystal display element using the vertical alignment type 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 a method such as a roll coater method, a spinner method, a printing method, an ink jet method, etc. 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 the 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. The heating temperature after application of the liquid crystal aligning agent is preferably 80 to 300 ° C, more preferably 120 to 250 ° C. The liquid crystal aligning agent of the present invention forms a resin film that becomes an alignment film by removing the organic solvent after coating. However, when imidization has not progressed completely, dehydration ring closure proceeds by further heating. It is also possible to obtain a more imidized resin film. 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.

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

Further, various measurements in Examples and Comparative Examples were performed by the following methods.
(1) Imidation rate of imidized polymer The imidized polymer was dried at room temperature under reduced pressure, then dissolved in deuterated dimethyl sulfoxide, and ¹ H-NMR was measured at room temperature using tetramethylsilane as a reference substance. It calculated | required by the formula shown by Formula (i).
Formula (i) Imidation ratio (%) = (1-A ¹ / A ² × α) × 100
A ¹ : Peak area derived from NH group protons (10 ppm)
A ² : Peak area derived from protons derived from aromatic rings (7 to 8 ppm)
α: The ratio of the number of protons derived from the aromatic ring to one NH group proton in the precursor (polyamic acid) of the polymer (2) Solution viscosity of the polymer The solution viscosity (mPa · s) of the polymer is a predetermined value. A solution diluted with a solvent to a solid content concentration of 10% by weight was measured at 25 ° C. using an E-type rotational viscometer.
(3) Vertical alignment evaluation:
When the vertically aligned liquid crystal display device manufactured by the above method is visually observed from the vertical direction with respect to the liquid crystal display device when no voltage is applied under crossed Nicols and an AC voltage of 8 V (peak-peak) is applied, light leakage occurs. “Good” when white display was made without any poor display.
(4) Printability evaluation:
Viscosity 15 to 25 mPa · sec (solid content concentration 6.0 wt% to 8.0 wt%), solvent composition γ-butyrolactone: N-methyl-2-pyrrolidone: butyl cellosolve = 0: 50: 50, or 40:30 : 30 (weight ratio) was prepared, and after the coating solution was formed and baked by the printing method using the prepared solution, the coating film was visually observed. A coating film having no repellency or coating unevenness was defined as “good”.
(5) Reliability evaluation In the above (3), using a liquid crystal display element exhibiting good vertical alignment, after continuously driving in a constant temperature bath at 60 ° C. for 48 hours, display defects, generation of stains, voltage holding Reliability was judged by confirming the change in rate.

<Synthesis Examples 16-21>
To the N-methyl-2-pyrrolidone, a diamine compound and a tetracarboxylic dianhydride (indicated in the table as “acid anhydride”) were added in this order with the composition shown in Table 1 to obtain a solid content concentration of 20% by weight. By preparing a solution and reacting at 60 ° C. for 4 hours, solutions of (PA-1) to (PA-6), which are polyamic acid polymers having the solution viscosity shown in Table 1, were obtained.

<Synthesis Examples 1-15>
To N-methyl-2-pyrrolidone, a diamine compound and tetracarboxylic dianhydride (shown as “acid anhydride” in the table) in the order shown in the compositions shown in Table 1 and Table 2 were added in this order to obtain a solid concentration of 20 A polyamic acid polymer was obtained by preparing a weight% solution and reacting at 60 ° C. for 4 hours. 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. After completion of the imidization reaction, the solvent in the system was replaced with new N-methyl-2-pyrrolidone (by this operation, pyridine and acetic anhydride used in the imidization reaction were removed from the system), and Table 1 shows. Solutions of (PI-1) to (PI-15), which are polymers having the indicated solution viscosity and imidization ratio, were obtained.

In the diamine compounds and acid anhydrides in Table 1, the numbers in parentheses indicate the content ratio, and the meanings of the symbols in Table 1 are as follows.
<Diamine compound>
D-1: Diamine compound represented by the above formula (10) D-2: Diamine compound represented by the above formula (11) D-3: Diamine compound represented by the above formula (13) D-4: Above Diamine compound D-5 represented by formula (21): p-phenylenediamine D-6: 4,4′-diaminodiphenylmethane D-7: 4,4′-diaminodiphenyl ether D-8: 2,2′-dimethyl -4,4'-diaminobiphenyl <tetracarboxylic dianhydride>
T-1: 1,2,4,5-cyclohexanetetracarboxylic dianhydride T-2: 2,3,5-tricarboxycyclopentylacetic acid dianhydride T-3: 1,2,3,4-cyclobutanetetra Carboxylic dianhydride T-4: 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-5: pyromellitic dianhydride

<Example 1>
The polymer (PI-1) obtained in Synthesis Example 1 was dissolved in a mixed solution of γ-butyrolactone / N-methyl-2-pyrrolidone / butyl cellosolve (γBL / NMP / BC), and 1,3-bis (N , N-diglycidylaminomethyl) benzene (additive A) is dissolved in an amount of 20 parts by weight with respect to 100 parts by weight of the polymer, and the solvent composition is γBL / NMP / BC = 0/50/50 by weight ratio, solid content concentration A 6 wt% solution was prepared. Subsequently, it filtered using the filter with a hole diameter of 0.2 micrometer, and obtained the liquid crystal aligning agent which concerns on this invention. When this liquid crystal aligning agent was evaluated for printability, no repelling or coating unevenness was observed in the coating film, and it was confirmed that the liquid crystal alignment agent had good printability. Subsequently, the liquid crystal aligning agent which concerns on this invention was prepared like the above except having made solid content concentration into 4%.
The obtained liquid crystal aligning agent was applied onto a transparent conductive film made of an ITO film provided on one surface of a glass substrate having a thickness of 1 mm by a spinner and dried at 200 ° C. for 60 minutes. A film of 08 μm was formed.
The surface of this coating is rubbed with a rubbing machine having a roll wrapped with a rayon cloth under the conditions of a roll rotation speed of 400 rpm, a stage moving speed of 3 cm / sec, and a limb pushing length of 0.4 mm. Thus, a liquid crystal alignment film was formed.
In this way, two liquid crystal display element substrates were prepared, and aluminum oxide spheres having a diameter of 3.5 μm were contained in the outer edge portion of the surface on which the liquid crystal alignment film was formed in each of these liquid crystal display element substrates. After applying the epoxy resin adhesive, the liquid crystal alignment films were overlapped and pressed through a gap so as to face each other, and the adhesive was cured in this state.
Next, a negative type liquid crystal (MLC-6608, manufactured by Merck & Co., Inc.) is filled in the cell gap between the liquid crystal display element substrates through a liquid crystal injection port provided in advance, and then the injection port is sealed with an acrylic photo-curing adhesive And the liquid crystal display element was produced by sticking a polarizing plate on both surfaces of the outer side of the board | substrate for liquid crystal display elements.
When the vertical alignment evaluation was performed on the obtained liquid crystal display element, it was good. Further, when a reliability test was measured, display unevenness, spots, and a decrease in voltage holding ratio were not confirmed even in constant temperature continuous driving, and the reliability was good.

<Examples 2-28 and Comparative Examples 1-6>
According to the formulation shown in the following Table 2 and Table 3, a solution having a solid content concentration of 6% was prepared in the same manner as in Example 1 to obtain a liquid crystal aligning agent, and the printability of the liquid crystal aligning agent was evaluated. Similarly, a film-forming composition having a solid content concentration of 4% was prepared to produce a liquid crystal display device. Then, vertical alignment evaluation and reliability test were performed. The results are shown in Tables 2 and 3.

In the polymers of Examples 21 to 28 in Table 2, the mixing ratio of the two polymers is 50/50 (% by weight).
The additives shown in Table 2 and Table 3 are as follows.
<Additives>
Additive A: 1,3-bis (N, N-diglycidylaminomethyl) benzene additive B: 1,4-bis (N, N-diglycidylaminomethyl) benzene additive C: 1,3-bis ( N, N-diglycidylaminomethyl) cyclohexane additive D: N, N, N ′, N′-tetraglycidyl-p-phenylenediamine additive E: N, N, N ′, N′-tetraglycidyl-4, 4'-diaminodiphenylmethane additive F: polyethylene glycol diglycidyl ether (molecular weight about 400)

  As is clear from the above results, it was confirmed that the liquid crystal aligning agent according to the present invention has a good printability and forms a liquid crystal alignment film excellent in vertical alignment and reliability.

Claims (7)

At least one repeating unit selected from the group consisting of repeating units represented by the following formula (I-1) and the following formula (I-2), which is obtained by a reaction between a tetracarboxylic dianhydride and a diamine compound. made, two as Q ² in Q ¹ and formula in the following formula (I-1) (I- 2), represented by the respective following formulas (II-1) and formula (II-2) A polymer containing a repeating unit having at least one of valent organic groups, and
A vertical alignment liquid crystal aligning agent comprising an epoxy compound represented by the following formula (III):

(In Formula (I-1), P ¹ is a tetravalent organic group derived from tetracarboxylic acid, and Q ¹ is a divalent organic group derived from a diamine compound. Also, Formula (I-2) P ² is a tetravalent organic group derived from tetracarboxylic acid, and Q ² is a divalent organic group derived from a diamine compound.)

(In the formula (II-1), X ¹ is a single bond, —O—, —CO—, —COO—, —OCO—, —NHCO—, —CONH—, —S—, a methylene group, 2 carbon atoms. An alkylene group having 6 to 6 carbon atoms or a phenylene group, and R ¹ is an alkyl group having 10 to 20 carbon atoms, a monovalent organic group having an alicyclic skeleton having 4 to 40 carbon atoms, or a fluorine atom having 6 to 20 carbon atoms. In Formula (II-2), X ¹ is a single bond, —O—, —CO—, —COO—, —OCO—, —NHCO—, —CONH—. , —S—, a methylene group, an alkylene group having 2 to 6 carbon atoms, or a phenylene group, and R ² is a divalent organic group having an alicyclic skeleton having 4 to 40 carbon atoms or a group having 5 to 30 carbon atoms. (It is a divalent organic group having a fluorine atom.)

(In the formula (III), a is an integer of 2 to 4, R ³ is an a-valent organic group, and the bonding sites for a N are aliphatic carbons.) The polymer is a divalent organic group represented by each of formula (II-1) and formula (II-2) as Q ¹ in formula (I-1) and Q ² in formula (I-2). 2. The vertical alignment type liquid crystal aligning agent according to claim 1, comprising a repeating unit having at least one of at least 7 mol% of all repeating units.   The tetracarboxylic dianhydride for obtaining the repeating unit represented by the formula (I-1) or the formula (I-2) includes 2,3,5-tricarboxycyclopentylacetic dianhydride, The vertical alignment type liquid crystal aligning agent according to claim 1 or 2.   4. The polymer according to claim 1, wherein the polymer contains at least one of the repeating units represented by formula (I-2) containing 40 mol% or more of all repeating units. 5. Vertical alignment type liquid crystal aligning agent. The vertical alignment type liquid crystal aligning agent according to any one of claims 1 to 4, wherein the epoxy compound includes one in which R ³ in the formula (III) is an aromatic ring skeleton or an alicyclic skeleton.   6. The vertical alignment type liquid crystal aligning agent according to claim 1, wherein the content of the formula (III) is 5 to 45% by weight in the solid content.   A liquid crystal display element comprising a liquid crystal alignment film obtained from the vertical alignment type liquid crystal aligning agent according to claim 1.