JPH11109365A - Liquid crystal orienting agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a liquid crystal orienting agent from which a liquid crystal orienting film with good orienting property for a liquid crystal can be obtd. by incorporating a polymer selected from imidized polymers and incorporating a solvent selected from specified solvents. SOLUTION: The liquid crystal orienting agent used contains at least one kind of polymer selected from a group of polyamic acids obtd. by the reaction of tetracarboxylic acid dianhydrides and diamine compds. and imidized polymers having a structure obtd. by dehydration cyclization of polyamic acids, and contains at least one kind of solvent selected from a group of solvents expressed by the formula. In the formula, X is a univalent org. group selected from 1-6C alkyl groups and 1 to 3C acyl groups, Y<1> to Y<5> are hydrogen atoms or univalent org. groups selected from 1-6C alkyl groups and 1-3C acyl groups, and each Y<1> to Y<5> present in plurality may be same or different.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a liquid crystal aligning agent used for forming a liquid crystal alignment film of a liquid crystal display device. More specifically, a liquid crystal that has good liquid crystal alignment properties, is a liquid crystal alignment agent that can be applied and formed on a resin substrate such as a polyacrylate resin, and provides a liquid crystal alignment film having a high voltage holding ratio in a liquid crystal display device. Related to an alignment agent.

[0002]

2. Description of the Related Art Conventionally, a sandwich structure is formed by forming a layer of a nematic liquid crystal having a positive dielectric anisotropy between two substrates having a liquid crystal alignment film formed on the surface thereof through a transparent conductive film. A TN (Twisted Nematic) liquid crystal cell in which the major axis of the liquid crystal molecules is continuously twisted by 90 degrees from one substrate to the other substrate is known. . Orientation of liquid crystal in a liquid crystal display device such as a TN type display device is usually realized by a liquid crystal alignment film provided with an alignment ability of liquid crystal molecules by a rubbing process. Here, as a material of a liquid crystal alignment film constituting a liquid crystal display element, resins such as polyimide, polyamide, and polyester are conventionally known. In particular, polyimide is used in many liquid crystal display devices because of its excellent heat resistance, affinity with liquid crystal, mechanical strength, and the like.

[0003]

However, liquid crystal aligning agents containing a conventionally known polyamic acid or an imidized polymer (polyimide) obtained by dehydrating and ring-closing the polyamic acid include γ-butyrolactone and N-methyl- as main solvents. When a highly polar solvent such as 2-pyrrolidone is used, and a liquid crystal display device or the like is manufactured using such a liquid crystal alignment agent,
If a resin substrate such as a polyacrylate resin is used as the substrate for the purpose of weight reduction or the like, a problem may occur such that the substrate dissolves during firing and film formation and a liquid crystal display element cannot be formed. If a solvent that does not dissolve the resin substrate is used, the solubility of the resin, which is the main component of the alignment agent, will be deteriorated, which may cause a problem that the uniformity of the thickness of the obtained liquid crystal alignment film is deteriorated. The present invention has been made in view of the above circumstances, and a first object of the present invention is to provide a liquid crystal alignment agent capable of obtaining a liquid crystal alignment film having good liquid crystal alignment. . A second object of the present invention is to provide a liquid crystal alignment agent that can be applied and formed on a resin substrate such as a polyacrylate resin. A third object of the present invention is to provide a liquid crystal aligning agent that provides a liquid crystal alignment film having excellent film thickness uniformity.

[0004]

According to the present invention, the above objects and advantages of the present invention are achieved by the following liquid crystal aligning agents. (1) Polyamic acid obtained by reacting a tetracarboxylic dianhydride with a diamine compound (hereinafter also referred to as “specific polymer (A)”) and imidization having a structure obtained by dehydrating and ring-closing the polyamic acid At least one polymer selected from the group consisting of polymers (hereinafter, also referred to as “specific polymer (B)”); and (2) the following formula (i):

[0005]

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(Wherein X represents a monovalent organic group selected from an alkyl group having 1 to 6 carbon atoms and an acyl group having 1 to 3 carbon atoms, and Y ^{1 to} Y ⁵ represent a hydrogen atom, A monovalent organic group selected from an alkyl group having 1 to 6 carbon atoms and an acyl group having 1 to 3 carbon atoms, and a plurality of Y ¹ to Y ⁵ may be the same or different.)

[0007] A liquid crystal aligning agent comprising at least one solvent selected from the group consisting of solvents represented by the following formula (hereinafter also referred to as "specific solvent (C)").

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The liquid crystal aligning agent of the present invention is constituted by dissolving the specific polymer (A) and / or the specific polymer (B) in the specific solvent (C). The specific polymer (A) constituting the liquid crystal aligning agent of the present invention is a polyamic acid obtained by reacting a tetracarboxylic dianhydride with a diamine compound, and the specific polymer forming the liquid crystal aligning agent of the present invention. (B)
Is an imidized polymer having a structure in which the specific polymer (A) is dehydrated and closed.

<Tetracarboxylic dianhydride> The tetracarboxylic dianhydride used in the synthesis of the specific polymer (A) is not particularly limited. For example, butanetetracarboxylic dianhydride, 1, 2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,
2,3,4-cyclobutanetetracarboxylic dianhydride,
1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dichloro-1,2,2
3,4-cyclobutanetetracarboxylic dianhydride, 1,
2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5
-Cyclohexanetetracarboxylic dianhydride, 3,
3 ', 4,4'-dicyclohexyltetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 3,5,6-tricarboxynorbornane-2-acetic dianhydride, 2,3 , 4,5-tetrahydrofurantetracarboxylic dianhydride, 1,3,3a, 4
5,9b-Hexahydro-5 (tetrahydro-2,5-
Dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-
Hexahydro-5-methyl-5 (tetrahydro-2,5
-Dioxo-3-furanyl) -naphtho [1,2-c]-
Furan-1,3-dione, 1,3,3a, 4,5,9b
-Hexahydro-5-ethyl-5 (tetrahydro-2,
5-dioxo-3-furanyl) -naphtho [1,2-c]
-Furan-1,3-dione, 1,3,3a, 4,5,9
b-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, 1,3,3
a, 4,5,9b-Hexahydro-8-ethyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,
3a, 4,5,9b-Hexahydro-5,8-dimethyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 5- (2,5-dioxotetrahydrofural) -3
-Methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, bicyclo [2,2,2] -oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, the following formula ( Aliphatic and cycloaliphatic tetracarboxylic dianhydrides such as compounds represented by I) and formula (II);

[0010]

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

Pyromellitic dianhydride, 3,3 ', 4
4'-benzophenonetetracarboxylic dianhydride, 3,
3 ', 4,4'-biphenylsulfonetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3 , 3 ′, 4,4′-biphenylethertetracarboxylic dianhydride, 3,3 ′, 4,4′-dimethyldiphenylsilanetetracarboxylic dianhydride,
3,3 ', 4,4'-tetraphenylsilanetetracarboxylic dianhydride, 1,2,3,4-furantetracarboxylic dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) ) Diphenyl sulfide dianhydride, 4,4 '
-Bis (3,4-dicarboxyphenoxy) diphenylsulfone dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenylpropane dianhydride, 3,
3 ', 4,4'-perfluoroisopropylidene diphthalic dianhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride, bis (phthalic acid) phenylphosphine oxide dianhydride, p -Phenylene-bis (triphenylphthalic acid) dianhydride, m-phenylene-bis (triphenylphthalic acid) dianhydride, bis (triphenylphthalic acid) -4,4'-diphenyl ether dianhydride, bis (tri Phenylphthalic acid) -4,4′-diphenylmethane dianhydride, ethylene glycol-bis (anhydrotrimellitate), propylene glycol-bis (anhydrotrimellitate), 1,4-butanediol-bis (anhydrotrimeritate) Trimellitate), 1,6-hexanediol-bis (anhydrotrimellitate),
1,8-octanediol-bis (anhydrotrimellitate), 2,2-bis (4-hydroxyphenyl) propane-bis (anhydrotrimellitate), represented by the following formulas (1) to (4) And aromatic tetracarboxylic dianhydrides such as These are used alone or in combination of two or more.

[0013]

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Of these, butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride Anhydride, 1,2,3,4-
Cyclopentanetetracarboxylic dianhydride, 2,3,5
-Tricarboxycyclopentylacetic dianhydride, 5-
(2,5-dioxotetrahydrofural) -3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, 1,3,3a, 4,5,9b-hexahydro-5-
(Tetrahydro-2,5-dioxo-3-furanyl)-
Naphtho [1,2-c] furan-1,3-dione, 1,
3,3a, 4,5,9b-hexahydro-8-methyl-
5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione;
1,3,3a, 4,5,9b-hexahydro-5,8-
Dimethyl-5- (tetrahydro-2,5-dioxo-3
-Furanyl) -naphtho [1,2-c] furan-1,3-
Dione, bicyclo [2,2,2] -oct-7-ene-
2,3,5,6-tetracarboxylic dianhydride, the compounds represented by the above formulas (1) to (4), and the compounds represented by the above formula (I), the following formulas (5) to (7) The compound represented by the following formula (8) among the compound represented by the formula (II) and the compound represented by the above formula (II) develops a good liquid crystal alignment property, and particularly, a liquid crystal alignment excellent in film thickness uniformity. Preferred from the viewpoint that a film can be obtained, and particularly preferred are 1,
2,3,4-cyclobutanetetracarboxylic dianhydride,
1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 1,3,3a, 4,5,9
b-Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-
1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan- 1,3-dione can be mentioned.

[0015]

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<Diamine compound> The above specific polymer (A)
The diamine compound used for the synthesis of is not particularly limited. For example, 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, 3,3-dimethyl-4,4'-diaminobiphenyl, 5-amino-1- (4'-aminophenyl) -1,3,3-trimethylindane, 6-amino-1- (4'- Aminophenyl) -1,3,3-trimethylindane, 3,4′-diaminodiphenyl ether, 3,3′-diaminobenzophenone, 3,4′-diaminobenzophenone, 4,4′-diaminobenzophenone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2
-Bis (4-aminophenyl) hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] sulfone, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4 -Aminophenoxy)
Benzene, 1,3-bis (3-aminophenoxy) benzene, 9,9-bis (4-aminophenyl) -10-hydroanthracene, 2,7-diaminofluorene, 9,
9-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 Aromatic diamines such as' -bis [(4-amino-2-trifluoromethyl) phenoxy] -octafluorobiphenyl;

1,1-meta-xylylenediamine, 1,3
-Propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, 4,4-diaminoheptamethylenediamine, 1,4-diaminocyclohexane, isophoronediamine, tetrahydrodicyclo Pentadienylenediamine, hexahydro-4,7-methanoindanylene dimethylenediamine, tricyclo [6,2,1,02.7]-
Aliphatic and alicyclic diamines such as undecylenedimethyldiamine and 4,4'-methylenebis (cyclohexylamine); mono-substituted phenylenediamines represented by the following formula (III); diaminoorgano represented by the following formula (IV) Siloxane; examples include compounds represented by the following formulas (9) to (13). These diamine compounds can be used alone or in combination of two or more.

[0018]

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(Wherein R ⁵ represents —O—, —COO—,
OCO-, -NHCO-, -CONH- and -CO-
And R ⁶ represents a monovalent organic group having a steroid skeleton or a trifluoromethyl group. )

[0020]

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(Wherein R ⁷ represents a hydrocarbon group having 1 to 12 carbon atoms, a plurality of R ^{7 s} may be the same or different, p is an integer of 1 to 3, and q is 1-2
It is an integer of 0. )

[0022]

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(In the formula, y is an integer of 2 to 12, and z is an integer of 1 to 5.)

Of these, p-phenylenediamine,
4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfide, 1,5-diaminonaphthalene, 2,7-diaminofluorene, 4,4'-diaminodiphenylether, 2,2-bis [4- (4- Aminophenoxy) phenyl] propane, 9,9-bis (4-
Aminophenyl) fluorene, 2,2-bis [4- (4
-Aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4 ′-(p-phenylenediisopropylidene) bisaniline, 4,4 ′-(m-phenylene Isopropylidene) bisaniline, 1,4-cyclohexanediamine, 4,4′-methylenebis (cyclohexylamine), 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, Among the compounds represented by the above formulas (9) to (13) and the compound represented by the above formula (III), the following formulas (14) to (13)
The compound represented by (19) is preferred. In particular, 4,4 '
-Diaminodiphenylmethane, the above formulas (9) to (11)
And the compounds represented by the following formulas (14) to (19) are preferred from the viewpoint of solubility in the specific solvent (C). These diamines may be used as they are, or may be used after being reduced again.

[0025]

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<Ratio of Use of Tetracarboxylic Dianhydride and Diamine Compound> The ratio of use of the tetracarboxylic dianhydride and the diamine compound in the synthesis reaction of the specific polymer (A) depends on the amino group contained in the diamine compound. The ratio is preferably such that the amount of the acid anhydride group contained in the tetracarboxylic dianhydride is 0.2 to 2 equivalents, more preferably 0.3 to 1.4 equivalents. In both the case where the ratio of the acid anhydride group contained in the tetracarboxylic dianhydride is less than 0.2 equivalent and the case where the ratio exceeds 2 equivalents, the molecular weight of the obtained polymer becomes too small, and the application of the liquid crystal aligning agent is performed. The properties may be poor.

<Synthesis of Specific Polymer (A)> The synthesis reaction of the specific polymer (A) constituting the liquid crystal aligning agent of the present invention is usually performed in an organic solvent at 0 to 150 ° C., preferably 0 to 100 ° C.
Is performed under the following temperature conditions. When the reaction temperature is 0 ° C or lower, the solubility of the compound in the solvent may be poor,
If the temperature exceeds ℃, the molecular weight of the obtained polymer may decrease.

The organic solvent used for the synthesis of the specific polymer (A) is a solvent capable of dissolving the tetracarboxylic dianhydride, the diamine compound and the specific polymer (A) formed by the reaction, and a polyacrylate resin. Solvents that hardly dissolve the resin substrate are preferred, and particularly preferred are specific solvents represented by the above formula (i). In particular,
Triglycol-based solvents such as triethylene glycol dimethyl ether, triethylene glycol diethyl ether, tripropylene glycol dimethyl ether, and tripropylene glycol diethyl ether can be mentioned, and these can be used alone or in combination of two or more. The amount (a) of the organic solvent used is such that the total amount (b) of the tetracarboxylic dianhydride and the diamine compound as the reaction raw materials is 0.1 to 30% by weight based on the total amount (a + b) of the reaction solution. It is preferable that the amount is large.

The above organic solvent is used in combination with a poor solvent for the specific polymer (A), such as alcohols, ketones, esters, and ethers, as long as the generated specific polymer (A) does not precipitate. can do. Specific examples of such poor solvents include, for example, methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, ethylene glycol, propylene glycol,
4-butanediol, triethylene glycol, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, diethyl oxalate, diethyl malonate, diethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, Ethylene glycol monobutyl ether, ethylene glycol dimethyl ether, 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, ethylene glycol methyl ether acetate, propylene Recol methyl ether, propylene glycol ethyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, dipropylene glycol methyl ether, dipropylene glycol ethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, ethylene glycol ethyl ether acetate, 4-hydroxy -4-methyl-2-pentanone,
Ethyl 2-hydroxypropionate, ethyl lactate, methyl lactate, butyl lactate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, 3- Methyl ethoxypropionate,
3-methyl-3-methoxybutanol, 3-ethyl-3
-Methoxybutanol, 2-methyl-2-methoxybutanol, 2-ethyl-2-methoxybutanol, 3-methyl-3-ethoxybutanol, 3-ethyl-3-ethoxybutanol, 2-methyl-2-ethoxybutanol, 2 Examples thereof include -ethyl-2-ethoxybutanol, tetrahydrofuran, and solvents represented by the following formulas (20) to (24). These can be used alone or in combination of two or more.

[0030]

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Wherein R ^{8 to} R ³⁵ each represent a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group having 1 to 4 carbon atoms, an alkoxyl group having 1 to 4 carbon atoms or a phenyl group; Is an integer of 1 to 5, respectively. R ⁸ ~
When a plurality of groups represented by R ³⁵ are present, they may be the same or different. ]

As the solvent represented by the above formula (20),
For example, 2-hydroxyethyl acetate, 2-hydroxypropyl acetate, 3-hydroxypropyl acetate, 2-hydroxybutyl acetate, 3-hydroxybutyl acetate, 4-hydroxybutyl acetate, 2-hydroxyethyl propionate, 2-hydroxypropyl propionate Pionate, 3-hydroxypropyl propionate, 2-hydroxyethyl lactate, 2
-Hydroxypropyl lactate, 3-hydroxypropyl lactate and the like. Examples of the solvent represented by the above formula (21) include 2,4-pentanedione, 1-hydroxy-2,4-pentanedione, 2,4-hexanedione, 2,5-hexanedione, Hydroxy-2,4-hexanedione, 2,4
-Heptanedione, 2,5-heptanedione, 2,6-
Heptanedione, 3,5-heptanedion, 2,4-octanedione, 2,5-octanedione, 2,6-octanedione, 2,7-octanedione, 3,5-octanedione and the like can be mentioned. . In addition, the above equation (2)
Examples of the solvent represented by 2) include methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, hydroxymethyl pyruvate, hydroxyethyl pyruvate, methyl acetoacetate, ethyl acetoacetate, propyl acetoacetate, and acetoacetate. Examples thereof include butyl, hydroxymethyl acetoacetate, and hydroxyethyl acetoacetate. Examples of the solvent represented by the above formula (23) include tetrahydrofurfuryl alcohol, tetrahydro-3-furanmethanol, tetrahydro-2-furanethanol, and tetrahydro-3-furanethanol. Further, as the solvent represented by the above formula (24), 1,3-dioxolan, 1,3-
Dioxepane, 4-methyl-1,3-dioxolan, 4
-Ethyl-1,3-dioxolan, 4-propyl-1,
3-dioxolan, 4-butyl-1,3-dioxolan, 2-methyl-1,3-dioxolan, 2-ethyl-
1,3-dioxolan, 3-propyl-1,3-dioxolan, 2,4-dimethyl-1,3-dioxolan, 2,
-Ethyl-4-methyl-1,3-dioxolan, 2-propyl-4-methyl-1,3-dioxolan and the like.

By the above synthesis reaction, a polymer solution obtained by dissolving the specific polymer (A) is obtained. And
This polymer solution is poured into a large amount of a poor solvent to obtain a precipitate,
The specific polymer (A) can be obtained by drying this precipitate under reduced pressure. Further, the specific polymer (A) can be purified by performing the step of dissolving the specific polymer (A) again in the organic solvent and then performing the precipitation with the poor solvent once or several times.

<Specific Polymer (B)> The specific polymer (B) constituting the liquid crystal aligning agent of the present invention is the above specific polymer (A).
Is an imidized polymer having a structure obtained by dehydration and ring closure, and is usually a polyimide and / or polyisoimide. The specific polymer (B) is obtained by the following methods (1) to (3)
Can be prepared.

Method (1): A method in which the specific polymer (A) is heated to effect dehydration ring closure. The reaction temperature in this method is usually from 60 to 200 ° C, preferably from 100 to 170 ° C. When the reaction temperature is lower than 60 ° C., the dehydration ring-closing reaction (imidization reaction) does not sufficiently proceed, and when the reaction temperature exceeds 200 ° C., the molecular weight of the specific polymer (B) obtained may be small. Method (2): a method in which the specific polymer (A) is dissolved in an organic solvent, a dehydrating agent and an imidization catalyst are added to the solution, and the solution is heated if necessary. In this method, as the dehydrating agent, for example, acetic anhydride,
Acid anhydrides such as propionic anhydride and trifluoroacetic anhydride can be used. The amount of the dehydrating agent used is preferably 1.6 to 20 mol per 1 mol of the repeating unit of the specific polymer (A). Further, as the imidation catalyst,
For example, tertiary amines such as pyridine, collidine, lutidine, and triethylamine can be used, but are not limited thereto. The amount of the imidization catalyst used is preferably 0.5 to 10 mol per 1 mol of the dehydrating agent used. In addition, as the organic solvent used for the imidization reaction, the organic solvents exemplified as those used for the synthesis of the specific polymer (A) can be mentioned. And
The reaction temperature of the imidization reaction is usually 0 to 180 ° C, preferably 60 to 150 ° C. Method (3): A method of mixing and condensing a tetracarboxylic dianhydride and a diisocyanate compound.

Specific examples of the diisocyanate compound used in this method include: an aliphatic diisocyanate compound such as hexamethylene diisocyanate; an alicyclic diisocyanate compound such as cyclohexane diisocyanate; diphenylmethane-4,4′-diisocyanate;
Diphenyl ether-4,4'-diisocyanate, diphenylsulfone-4,4'-diisocyanate, diphenylsulfide-4,4'-diisocyanate,
2-diphenylethane-p, p'-diisocyanate,
2,2-diphenylpropane-p, p'-diisocyanate, 2,2-diphenyl-1,1,1,3,3,3-
Hexafluoropropane-p, p'-diisocyanate, 2,2-diphenylbutane-p, p'-diisocyanate, diphenyldichloromethane-4,4'-diisocyanate, diphenylfluoromethane-4,4'-diisocyanate, benzophenone-4, Aromatic diisocyanate compounds such as 4'-diisocyanate and N-phenylbenzoic amide-4,4'-diisocyanate can be mentioned, and these can be used alone or in combination of two or more. Note that this method does not require a catalyst, and the reaction temperature is usually 50 to 200 ° C.
Preferably it is 100-160 degreeC. The specific polymer (B) can be purified by performing the same operation as the method for purifying the specific polymer (A) on the polymer solution thus obtained.

<Logarithmic Viscosity of Polymer> The logarithmic viscosities (ηln) of the specific polymer (A) and the specific polymer (B) obtained as described above are usually 0.05 to 10 dl / g, and are preferably Is 0.05 to 5 dl / g. here,
The value of the logarithmic viscosity (ηln) is determined using N-methyl-2-pyrrolidone as a solvent and a polymer concentration of 0.5 g / 100.
The viscosity is measured at 30 ° C. for a solution of milliliter, and is determined by the following equation.

[0038]

(Equation 1)

<Terminal-Modified Polymer> The specific polymer (A) and / or the specific polymer (B) constituting the liquid crystal aligning agent of the present invention may be a terminal-modified polymer. The molecular weight of the terminal-modified polymer is controlled, and the coating characteristics of the liquid crystal aligning agent can be improved without impairing the effects of the present invention. The terminal-modified polymer can be synthesized by adding an acid anhydride, a monoamine compound or a monoisocyanate compound to the reaction system when synthesizing the specific polymer (A).

The acid anhydride to be added to the reaction system for synthesizing the specific polymer (A) to obtain a terminal-modified polymer includes, for example, maleic anhydride, phthalic anhydride, itaconic anhydride, n- Examples include decyl succinic anhydride, n-dodecyl succinic anhydride, n-tetradecyl succinic anhydride, and n-hexadecyl succinic anhydride. Further, as the monoamine compound added to the reaction system, for example, aniline, cyclohexylamine, n-butylamine, n-pentylamine,
n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, n-
Undecylamine, n-dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecylamine, n-octadecylamine, n-eicosylamine, etc. Can be mentioned. Examples of the monoisocyanate compound added to the reaction system include phenyl isocyanate and naphthyl isocyanate.

<Specific solvent (C)> The specific solvent (C) represented by the above formula (i) is usually a good solvent for the specific polymer (A) and the specific polymer (B). Specific examples of such a specific solvent (C) include, for example, triethylene glycol monomethyl ether, triethylene glycol monomethyl ether acetate, triethylene glycol dimethyl ether, triethylene glycol monoethyl ether, triethylene glycol monoethyl ether acetate, triethylene glycol Diethyl ether, triethylene glycol monopropyl ether, triethylene glycol monopropyl ether acetate, triethylene glycol dipropyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monomethyl ether acetate, tripropylene glycol dimethyl ether, tripropylene glycol monoethyl ether, Tripropylene glycol monoe And propylene glycol diethyl ether, tripropylene glycol monopropyl ether, tripropylene glycol monopropyl ether acetate, tripropylene glycol dipropyl ether, and the like. These may be used alone or in combination of two or more. Can be. Among these, from the viewpoint of the solubility of the polymer, etc., triethylene glycol monomethyl ether, triethylene glycol monomethyl ether acetate, triethylene glycol dimethyl ether, triethylene glycol monoethyl ether, triethylene glycol monoethyl ether acetate, triethylene glycol diethyl Ether, tripropylene glycol monomethyl ether, tripropylene glycol monomethyl ether acetate, tripropylene glycol dimethyl ether,
Tripropylene glycol monoethyl ether, tripropylene glycol monoethyl ether acetate, and tripropylene glycol diethyl ether are preferred.

<Liquid Crystal Alignment Agent> The liquid crystal alignment agent of the present invention may be used as a part or all of the solvent component for dissolving the polymer [specific polymer (A) and / or specific polymer (B)]. It is characterized in that the solvent (C) is contained.

The content ratio of the polymer component constituting the liquid crystal aligning agent is usually 1 to 10% by weight, preferably 3 to 8% by weight. If this ratio is less than 1% by weight, the thickness of the formed liquid crystal alignment film becomes too small, and pinholes are likely to be generated in the liquid crystal alignment film. On the other hand, when this ratio exceeds 10% by weight, the viscosity of the liquid crystal alignment agent becomes excessively high, and the uniformity of the thickness of the formed liquid crystal alignment film may be impaired.

The content ratio of the specific solvent (C) constituting the liquid crystal aligning agent of the present invention can be applied to a resin substrate such as a polyacrylate resin, has excellent film thickness uniformity, and
From the viewpoint of producing a liquid crystal display element having excellent display characteristics and electric characteristics, it is usually 5% by weight or more, preferably 10 to 90% by weight, based on the total amount of the solvent. When the content of the specific solvent (C) is less than 5% by weight,
In some cases, the resin substrate dissolves or the polymer component cannot be sufficiently dissolved, which causes generation of precipitates and gelation, so that a liquid crystal display element cannot be manufactured.

<Good solvent / Poor solvent that can be used in combination> The liquid crystal aligning agent of the present invention includes the specific polymer (A) and the specific polymer (B) as long as the effect of the specific solvent (C) is not impaired. And a poor solvent for these polymers.

Examples of the good solvent (hereinafter referred to as “good solvent (D)”) used as a solvent component of the liquid crystal aligning agent of the present invention include, for example, γ-butyrolactone, N-methyl-2-pyrrolidone, N, N-dimethyl Formamide, N, N-dimethylacetamide, dimethylsulfoxide, tetramethylurea, hexamethylphosphoryltriamide, 1,3-
Aprotic polar solvents such as dimethyl-2-imidazolidinone; m-cresol, xylenol, phenol,
Phenolic solvents such as halogenated phenols can be mentioned, and these can be used alone or in combination of two or more. Among them, N-alkyl-2-pyrrolidones such as N-methyl-2-pyrrolidone and N-ethyl-2-pyrrolidone; lactones such as γ-butyrolactone; and 1,3-dimethyl-2-imidazolidy Dialkylimidazolidinones such as nonone are preferred. The mixing ratio of the good solvent (D) in the liquid crystal aligning agent of the present invention is usually 40% by weight or less, preferably 30% by weight or less based on the total volume of the used solvent. If it exceeds 40% by weight, the resin substrate is easily dissolved.

The poor solvent (hereinafter referred to as “poor solvent (E)”) used as a solvent component of the liquid crystal aligning agent of the present invention includes those which can be used together in the synthesis of the specific polymer (A). The exemplified poor solvents can be mentioned. By using the liquid crystal alignment agent containing the poor solvent (E), the thickness uniformity of the liquid crystal alignment film to be formed can be further improved. The compounding ratio of the poor solvent (E) in the liquid crystal aligning agent of the present invention is usually 9 to the total volume used.
0% by weight or less, preferably 85% by weight or less. 90
If the content is more than 10% by weight, a specific polymer may be precipitated.
The particularly preferable solvent composition in the liquid crystal aligning agent of the present invention is 10 to 90% by weight of the specific solvent (C) and 0% of the good solvent (D).
-15% by weight and poor solvent (E) 10-85% by weight.

The method for preparing the liquid crystal aligning agent of the present invention includes:
[1] A solution is obtained by dissolving a polymer component [specific polymer (A) and / or specific polymer (B)] in a good solvent (D), and a specific solvent (C) and a poor solvent ( (2) a method of dissolving the polymer component in a mixed solvent comprising a specific solvent (C), a good solvent (D) and a poor solvent (E); A method of dissolving a polymer component to obtain a solution, and adding a good solvent (D) and a poor solvent (E) to the solution; [4] dissolving a part of the polymer component in a good solvent (D); The obtained solution is mixed with a solution obtained by dissolving the remainder of the polymer component in the specific solvent (C),
Next, various methods such as a method of adding a poor solvent (E) to the mixed solution can be adopted.

A functional silane-containing compound can be added to the liquid crystal aligning agent of the present invention from the viewpoint of improving the adhesion of the formed thin film to the substrate surface. Examples of such a functional silane-containing compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2
-Aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl -3-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, and The silane coupling agent containing a benzylideneimino group described in 136893, for example, 3- (m-chlorobenzylideneimino) propyltrimethoxysilane and the like can be mentioned.

<Liquid Crystal Display Device> A liquid crystal display device obtained by using the liquid crystal aligning agent of the present invention can be manufactured, for example, by the following method. (1) The liquid crystal aligning agent of the present invention is applied to the transparent electrode side of the substrate provided with the patterned transparent electrode by a method such as a roll coater method, a spinner method, or a printing method, and then the coated surface is heated. Thus, a thin film is formed. Here, as the substrate, for example, float glass, glass such as soda glass, polyethylene terephthalate,
Polybutylene terephthalate, polyether sulfone,
A substrate made of a plastic film such as polyacrylate or polycarbonate can be used. As a transparent electrode provided on one surface of the substrate, a NESA film made of SnO ₂ , an ITO film made of In ₂ O ₃ —SnO, or the like can be used. For the patterning of these transparent electrodes, a photo-etching method, A method using a mask in advance is used. When applying the liquid crystal aligning agent,
In order to further improve the adhesiveness between the substrate and the transparent electrode and the thin film, a functional silane-containing compound, titanate, or the like may be applied on the substrate and the transparent electrode in advance. The heating temperature is set to 80 to 250 ° C., preferably 12
0 to 200 ° C. The thickness of the formed thin film is usually 0.001 to 1 μm, preferably 0.005 to 0.5 μm.
5 μm.

(2) The formed thin film is subjected to a rubbing treatment in which the thin film is rubbed in a certain direction with a roll wrapped with a cloth made of a synthetic fiber such as nylon or rayon, so that the thin film is provided with the ability to align liquid crystal molecules. It becomes an alignment film. Also,
In addition to the rubbing method, a liquid crystal alignment film may be formed by irradiating the surface of the thin film with polarized ultraviolet rays to impart alignment ability, or by obtaining a thin film by a uniaxial stretching method, a Langmuir-Blodgett method, or the like. it can. Note that the formed liquid crystal alignment film is preferably washed with isopropyl alcohol or the like in order to remove fine powder (foreign matter) generated during the rubbing treatment and keep the surface clean. Further, by partially irradiating the liquid crystal alignment film formed by the liquid crystal alignment agent of the present invention with ultraviolet rays as shown in, for example, JP-A-6-222366 and JP-A-6-281937. A process in which a pretilt angle is changed or a resist film is partially formed on a rubbed liquid crystal alignment film as shown in JP-A-5-107544, which is different from the preceding rubbing process. After performing the rubbing process in the direction, by removing the resist film and performing a process for changing the alignment ability of the liquid crystal alignment film, the visibility characteristics of the liquid crystal display element can be improved.

(3) Two substrates on which the liquid crystal alignment films are formed as described above are prepared, and the two substrates are separated by a gap (so that the rubbing directions of the respective liquid crystal alignment films are orthogonal or antiparallel). (A cell gap), the peripheral portions of the two substrates are bonded together with a sealant, liquid crystal is filled into the surface of the substrate and the cell gap defined by the sealant, and the filling hole is sealed. To form a liquid crystal cell.
Then, a polarizing plate is provided on the outer surface of the liquid crystal cell, that is, on the other surface side of each substrate constituting the liquid crystal cell, and the polarization direction thereof coincides with or is orthogonal to the rubbing direction of the liquid crystal alignment film formed on one surface of the substrate. Thus, a liquid crystal display element is obtained. As the sealant,
For example, an epoxy resin containing a hardening agent and aluminum oxide spheres as a spacer can be used. Examples of the liquid crystal include a nematic liquid crystal and a smectic liquid crystal. Among them, a nematic liquid crystal is preferable.For example, a Schiff base liquid crystal, an azoxy liquid crystal, a biphenyl liquid crystal, a phenylcyclohexane liquid crystal, an ester liquid crystal, and a terphenyl liquid crystal. Liquid crystal, biphenylcyclohexane liquid crystal, pyrimidine liquid crystal, dioxane liquid crystal, bicyclooctane liquid crystal, cubane liquid crystal, and the like are used. In addition, cholesteric liquid crystals such as cholesteryl chloride, cholesteryl nonaate and cholesteryl carbonate, and chiral agents sold under the trade names “C-15” and “CB-15” (manufactured by Merck & Co.) It can also be used by adding it. In addition, ferroelectric liquid crystals such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate can be used. Further, as a polarizing plate used outside the liquid crystal cell, a polarizing plate in which a polarizing film called an H film absorbing iodine is sandwiched between cellulose acetate protective films while stretching and aligning polyvinyl alcohol,
Alternatively, a polarizing plate composed of the H film itself can be used.

[0053]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. The thin film formed using the liquid crystal aligning agents prepared in Examples 1 to 26 and Comparative Examples 1 to 3 was evaluated for film thickness uniformity, and the pretilt angle was determined for each of the manufactured liquid crystal display elements. In addition, the voltage holding ratio was measured, the liquid crystal orientation was evaluated, and the solubility of the polyacrylate resin substrate was evaluated. The measuring method and the evaluation method are as follows.

[Method of measuring pretilt angle] [TJS
chffer, et. al. , J. et al. Appl. Phys
s. , Vol. 19, 2013 (1980) ", and measured by a crystal rotation method using a He-Ne laser beam.

[Method of Measuring Voltage Holding Ratio] The liquid crystal display device was left in a thermostat at 60 ° C. for one month, and the voltage holding ratio (frame period of 16.7 msec) of the liquid crystal display device after standing was set to “VHR-1”. (Manufactured by Toyo Corporation).

[Evaluation Method of Liquid Crystal Orientation] The presence or absence of abnormal domains in the liquid crystal cell when the voltage was turned on / off in the liquid crystal display element was observed with a polarizing microscope. A certain case was judged as "poor".

[Evaluation Method of Solubility of Polyacrylate Resin Substrate] A 0.5 mm-thick polyacrylate resin film was cut into 1 cm square, and its initial weight (Wo) was measured. The mixture was placed in a mixed solvent having the same composition ratio as above, allowed to stand at a constant temperature for 24 hours, taken out, and the weight (W) after the solvent was thoroughly wiped was measured, and the rate of change was calculated by the following equation. . The above evaluation was carried out by changing the temperature of the mixed solvent by 5 ° C. at a rate of 9%.
The temperature at which the concentration became 4% or less was taken as the melting temperature.

[0058]

## EQU2 ## Rate of change (%) = W / W _o × 100

[Evaluation Method of Film Thickness Uniformity] The average thickness of the thin film and the difference between the maximum thickness and the minimum thickness (this is referred to as “maximum difference”) are measured using a stylus type thickness gauge. did.

Synthesis Example 1 224.17 g (1 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 10.81 g (0.1 mol) of p-phenylenediamine, 4,4′-diaminodiphenylmethane 19.83
g (0.1 mol) of the compound 4 represented by the above formula (14)
16.6 g (0.8 mol) was dissolved in 2000 g of triethylene glycol dimethyl ether.
The reaction was carried out at 6 ° C. for 6 hours. Next, the obtained reaction solution was poured into a large excess of methanol to precipitate a reaction product. Thereafter, the solid substance was separated, washed with pure water, and dried at 40 ° C. under reduced pressure for 15 hours to obtain a logarithmic viscosity (ηln).
0.3 dl / g of the specific polymer (A) [hereinafter referred to as “polymer (A)
-1) "] 604.5 g.

[Synthesis Example 2] 30.0 g of the polymer (A-1) obtained in Synthesis Example 1 was mixed with N-methyl-2-pyrrolidone 5
The resultant was dissolved in 70 g, and 15.8 g of pyridine and 20.4 g of acetic anhydride were added, followed by dehydration and ring closure at 110 ° C. for 3 hours. Subsequently, the reaction product is precipitated, separated, washed and dried in the same manner as in Synthesis Example 1A to obtain a logarithmic viscosity (η).
ln) 28.5 g of 0.2 dl / g of the specific polymer (B) [hereinafter referred to as “polymer (B-1)”] was obtained.

[Synthesis Example 3] Instead of the tetracarboxylic dianhydride used in Synthesis Example 1, 1,3,3a, 4,
5,9b-Hexahydro-8-methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,
2-c] -furan-1,3-dione 314.30 g (1
(Mol)) in the same manner as in Synthesis Example 1 except that the specific polymer (A) having a logarithmic viscosity (ηln) of 0.27 dl / g was used.
[Hereinafter referred to as “polymer (A-2)”] 685.4 g was obtained. Then, instead of the polymer (A-1), the polymer (A-
2) A specific polymer (B) having an intrinsic viscosity (ηln) of 0.21 dl / g [hereinafter referred to as “polymer (B-2)”] 27 in the same manner as in Synthesis Example 1B except that 30.0 g was used. .6
g was obtained.

Synthesis Example 4 In place of the diamine compound used in Synthesis Example 3, p-phenylenediamine 10.8 was used.
1 (0.1 mol), 164.2 g (0.4 mol) of 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 1- (3,5-diaminobenzoyloxy) -4
-(4-trifluoromethylbenzoyloxy) -cyclohexane (of the chemical formula represented by the above formula (18),
Those with a trifluoromethyl group at the para position. same as below. ) In the same manner as in Synthesis Example 3 except that 211.2 g (0.5 mol) was used, logarithmic viscosity (ηln) 0.23 d
1 / g of the specific polymer (A) [hereinafter referred to as “polymer (A-3)”
633.0 g was obtained. Then, the polymer (A-
In the same manner as in Synthesis Example 1B except that 30.0 g of the polymer (A-3) was used instead of 1), the logarithmic viscosity (ηln) was used.
28.6 g of 0.19 dl / g of the specific polymer (B) [hereinafter referred to as "polymer (B-3)"] was obtained.

Synthesis Example 5 Instead of the diamine compound used in Synthesis Example 3, 9.91 g (0.05 mol) of 4,4′-diaminodiphenylmethane and the above formula (1)
Logarithmic viscosity (η) in the same manner as in Synthesis Example 3 except that 494.8 g (0.95 mol) of the compound represented by 4) was used.
ln) 737.1 g of 0.20 dl / g of the specific polymer (A) [hereinafter referred to as “polymer (A-4)”] was obtained. After that, the polymer (A-4) was replaced with the polymer (A-4) 30.
Except that 0 g was used, the specific polymer (B) having a logarithmic viscosity (ηln) of 0.15 dl / g was prepared in the same manner as in Synthesis Example 1B.
[Hereinafter referred to as “polymer (B-4)”] 26.2 g was obtained.

[Synthesis Example 6] Instead of the tetracarboxylic dianhydride used in Synthesis Example 1, 201.75 g of 2,3,5-tricarboxycyclopentylacetic acid dianhydride was used.
(0.9 mol), pyromellitic dianhydride 21.81
(0.1 mol), and instead of the diamine compound used, 10.81 g (0.1 mol) of p-phenylenediamine, 1- (3,5-diaminobenzoyloxy) -4
Except that 380.2 g (0.9 mol) of-(4-trifluoromethylbenzoyloxy) -cyclohexane was used, the logarithmic viscosity (ηln) was 0.2 in the same manner as in Synthesis Example 1.
6 dl / g of the specific polymer (A) [hereinafter referred to as “polymer (A-
53.1 "] 553.1 g.

<Example 1> (1) Preparation of liquid crystal aligning agent: 57.5 g of the polymer (A-1) obtained in Synthesis Example 1 was mixed with 87.5 g of triethylene glycol dimethyl ether [specific solvent (C-1)]. And N-methyl-2-pyrrolidone [good solvent (D-1)] 8.5 g and 2
-Hydroxyethyl acetate [poor solvent (E-1)] 2
The resulting solution was dissolved in a mixed solvent of 4.0 g to obtain a solution, and the solution was filtered through a filter having a pore size of 1 μm to prepare a liquid crystal aligning agent. In this liquid crystal aligning agent, the polymer (A-
1) was 4.0% by weight, the specific solvent (C-1) was 70.0% by weight, the good solvent (D-1) was 6.8% by weight, and the poor solvent (E The content ratio of -1) is 1
9.2% by weight.

(2) Evaluation of Solubility of Polyacrylate Resin A mixed solvent having the same composition as the liquid crystal aligning agent was prepared, and the polyacrylate resin film was put in the mixed solvent, and the weight change after 24 hours at a constant temperature was measured. The temperature was measured and the rate of change was calculated by the above equation. The temperature at which this value was 94% or less was investigated.
It became clear that an alignment film could be formed by firing. Formation of Thin Film: (3) This liquid crystal aligning agent is applied to the transparent electrode surface of a polyacrylate substrate provided with a transparent electrode made of an ITO film by using a liquid crystal aligning agent printing press, and is heated at 100 ° C. for 1 hour. By drying, a thin film having an average thickness of 700 ° was formed. The maximum difference was 10 °, and the film thickness was excellent in uniformity.

(4) Formation of Liquid Crystal Alignment Film: The surface of the formed thin film is subjected to a rubbing treatment using a rubbing machine having a roll around which a cloth made of rayon is wound, so that the alignment ability of the liquid crystal molecules is reduced. It was applied to a thin film to form a liquid crystal alignment film. Here, the rubbing treatment conditions were as follows: the number of rotations of the roll was 500 rpm, and the moving speed of the stage was 1 cm /
Seconds, the length of the pressed foot was 0.4 mm.

(5) Production of liquid crystal display element: Two substrates on which a liquid crystal alignment film was formed as described above were produced, and an epoxy resin containing aluminum oxide spheres having a diameter of 17 μm on the outer edge of each substrate. Is applied by a screen printing method, and two substrates are opposed to each other with a gap therebetween so that the rubbing directions of the respective liquid crystal alignment films are orthogonal to each other, and the outer edges are brought into contact with each other and pressed to cure the adhesive. I let it. Next, the nematic liquid crystal “ML” is placed in the cell gap defined by the adhesive on the surface of the substrate and the outer edge.
C-2012 "(manufactured by Merck Japan) was injected and filled, and then the injection hole was sealed with an epoxy-based adhesive to form a liquid crystal cell. Next, a polarizing plate is attached to the outer surface of the liquid crystal cell, that is, the other surface of each substrate constituting the liquid crystal cell, such that the polarization direction matches the rubbing direction of the liquid crystal alignment film formed on one surface of the substrate. Thus, a liquid crystal display element was manufactured.

(6) Evaluation of liquid crystal display device: The liquid crystal display device manufactured as described above was examined for liquid crystal orientation. When the operating voltage was turned on and off, abnormal domains were found in the liquid crystal display device. It was not recognized, and it was recognized that it had favorable orientation. The pretilt angle of this liquid crystal display element was as high as 87.0 °, and the voltage holding ratio was 97.5%, exhibiting excellent electric characteristics.
Table 4 shows the above results.

<Examples 2 to 26> According to the formulations shown in Tables 1 and 2, a polymer [specific polymer (A) or specific polymer (B)] was dissolved in a mixed solvent to give a solid content of 4% by weight.
And a liquid crystal aligning agent of the present invention was prepared, a thin film was formed on a substrate, and the thin film was subjected to a rubbing treatment in the same manner as in Example 1 except that this solution was used. Was formed, and a liquid crystal display device including the liquid crystal alignment film was manufactured. The pretilt angle, voltage holding ratio, and residual voltage of each of the liquid crystal display devices manufactured as described above were measured, and the liquid crystal alignment was evaluated. The results are shown in Tables 4 and 5.

[0072]

[Table 1]

[0073]

[Table 2]

<Comparative Examples 1-2> According to the formulation shown in Table 3,
The polymer (B-1) obtained in Synthesis Example 1B was dissolved in a mixed solvent to obtain a solution, and a liquid crystal aligning agent for comparison was prepared in the same manner as in Example 1 except that this solution was used. Then, a thin film was formed on a substrate, a rubbing treatment was performed on the thin film to form a liquid crystal alignment film, and a liquid crystal display device including the liquid crystal alignment film was manufactured. The pretilt angle, voltage holding ratio, and residual voltage of each of the liquid crystal display devices manufactured as described above were measured, and the liquid crystal alignment was evaluated. Table 6 shows the results
Shown in

[0075]

[Table 3]

In Tables 1 to 3, the specific solvent (C), good solvent (D) and poor solvent (E) indicate the following solvents, respectively.

[Specific solvent (C)] (C-1): Triethylene glycol dimethyl ether (C-2): Triethylene glycol diethyl ether (C-3): Tripropylene glycol dimethyl ether (C-4) : Tripropylene glycol diethyl ether [Good solvent (D)] · (D-1): N-methyl-2-pyrrolidone · (D-2): N-ethyl-2-pyrrolidone · (D-3): γ- Butyrolactone (D-4): 1,3-dimethyl-2-imidazolidinone [Poor solvent (E)] • (E-1): Ethylene glycol monobutyl ether • (E-2): 2,4-pentanedione -(E-3): ethyl pyruvate-(E-4): tetrahydrofurfuryl alcohol-(E-5): 1,3-dioxolane

[0078]

[Table 4]

[0079]

[Table 5]

[0080]

[Table 6]

[0081]

The liquid crystal display device having a liquid crystal alignment film formed by using the liquid crystal alignment agent of the present invention can be suitably used for a TN type liquid crystal display device, and can also be used by selecting a liquid crystal to be used. Super Twisted Ne
magnetic) type, SH (Super Homeotro)
pic) type, IPS (In-Plane-Switch)
ing) type, OCB (Optically Compe)
It can also be suitably used for an nsated birefringence type, ferroelectric and antiferroelectric liquid crystal display device. Further, a liquid crystal display device having a liquid crystal alignment film formed using the liquid crystal alignment agent of the present invention can be effectively used for various devices, for example, a desk calculator, a wristwatch,
It is used for display devices such as clocks, coefficient display boards, word processors, personal computers, and liquid crystal televisions.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasuo Matsuki 2-11-24 Tsukiji, Chuo-ku, Tokyo Inside Nippon Gosei Rubber Co., Ltd.

Claims (1)

[Claims] At least one selected from the group consisting of (1) a polyamic acid obtained by reacting a tetracarboxylic dianhydride with a diamine compound and an imidized polymer having a structure obtained by dehydrating and ring-closing the polyamic acid. One kind of polymer, and (2) a compound represented by the following formula (i): (Wherein X is an alkyl group having 1 to 6 carbon atoms and 1 carbon atom
A monovalent organic group selected from to 3 acyl group, Y ¹
To Y ⁵ represents a hydrogen atom, a monovalent organic group selected from alkyl and acyl groups having 1 to 3 carbon atoms of 1 to 6 carbon atoms, and Y ¹ to Y ⁵ there are a plurality of, different from each identical May be. A) a liquid crystal aligning agent comprising at least one solvent selected from the group consisting of the solvents represented by