JPH08325573A - Orientation agent of liquid crystal - Google Patents

Abstract

PURPOSE: To obtain an orientation agent of liquid crystal formable of a liquid crystal orientation film giving a thin film having highly uniform film thickness, excellent liquid crystal orientation property and a liquid crystal display element having excellent electric properties. CONSTITUTION: This orientation agent contains a first polymer giving a thin film having high surface free energy and a second polymer giving a thin film having a surface free energy lower than the first polymer. Both of the first polymer and the second polymer are composed of at least one kind selected from a polyamic acid obtained by reacting tetracarboxylic acid dianhydride with a diamine compound and a polymer having a structure obtained by cyclodehydrating the polyamic acid, and a thin film having 38-60dyn/cm surface free energy is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal aligning agent used for forming a liquid crystal aligning film of a liquid crystal display device, and more specifically, it can form a thin film having a high film thickness uniformity by a printing method or the like. The present invention relates to a liquid crystal aligning agent capable of forming a liquid crystal aligning film having excellent liquid crystal aligning property and having excellent electrical characteristics.

[0002]

2. Description of the Related Art At present, as a liquid crystal display element, a liquid crystal alignment film is formed on a surface of a substrate provided with a transparent conductive film to form a liquid crystal display element substrate, and two of them are arranged so as to face each other. Inside, for example, a layer of a nematic liquid crystal having a positive dielectric anisotropy is formed into a sandwich structure cell,
A so-called TN in which the major axis of the liquid crystal molecule is continuously twisted by 90 degrees from one substrate to the other substrate.
A TN type liquid crystal display device having a (Twisted Nematic) type liquid crystal cell is known. Alignment of liquid crystal molecules in a liquid crystal display device such as the TN type liquid crystal display device is usually realized by a liquid crystal alignment film having an alignment ability with respect to the liquid crystal molecules by rubbing treatment. And, as a material of the liquid crystal alignment film constituting the liquid crystal display device, conventionally, polyamic acid or a polyimide obtained by dehydration ring closure of polyamic acid is known, which has heat resistance, affinity with liquid crystal, mechanical strength. It is used in many liquid crystal display devices because of its excellent properties.

[0003]

However, a liquid crystal aligning agent comprising a conventionally known solution of polyamic acid or a polyimide solution obtained by dehydration ring closure of polyamic acid is applied to a substrate for a liquid crystal display element by, for example, a printing method. In such a case, it is difficult to form a thin film having a high uniformity of film thickness, and the thin film is formed in a state of having a considerably large film thickness unevenness of, for example, 100 Å or more. There is a problem that it is not possible to form a liquid crystal alignment film that has good characteristics and electrical characteristics. In addition, in order to form a thin film with high uniformity of film thickness, it has been attempted to add a low molecular weight surfactant to the liquid crystal aligning agent. If it is used, there is a problem that the electrical characteristics of the liquid crystal display element are deteriorated because the surfactant in the liquid crystal alignment film is eluted into the liquid crystal material forming the liquid crystal display element.

The present invention has been made based on the above circumstances, and an object thereof is to form a thin film having a high film thickness uniformity and to have a good liquid crystal alignment property, and to have an electric property. An object of the present invention is to provide a liquid crystal aligning agent capable of forming a liquid crystal aligning film capable of obtaining a liquid crystal display device having excellent dynamic characteristics.

[0005]

The liquid crystal aligning agent of the present invention comprises:
A first polymer which gives a thin film having a high surface free energy, and a second polymer which gives a thin film having a lower surface free energy than the first polymer.
The polymer and the second polymer are both at least one selected from a polyamic acid obtained by reacting a tetracarboxylic dianhydride and a diamine compound and a polymer having a dehydrated and ring-closed structure thereof. , The surface free energy exceeds 38 dyn / cm, and 60 dyn /
It is characterized in that a thin film having a thickness of cm or less is formed.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below. The liquid crystal aligning agent according to the present invention contains both a first polymer that gives a thin film having a high surface free energy and a second polymer that gives a thin film having a lower surface free energy than the first polymer. The solution has a surface free energy of 38 dyn / cm when a thin film is formed.
Over 60 dyn / cm or less to form a thin film. Here, "a polymer that gives a thin film with high (or low) surface free energy" means that when the thin film is formed by applying a solution of the polymer onto the surface of the substrate and drying the thin film, A polymer having (or low) surface free energy.

The first component which is the first component of the liquid crystal aligning agent of the present invention
Is a polymer that gives a thin film having a high surface free energy, and specifically, a tetracarboxylic dianhydride (hereinafter also referred to as "compound (I)") and a diamine compound (hereinafter "compound (II ) ”).) A polyamic acid obtained by reacting with ()).
And at least one polymer selected from polymers having a structure obtained by dehydrating and ring-closing this polymer A (hereinafter, also referred to as “polymer B”). The second polymer, which is the second component of the liquid crystal aligning agent, is a polymer that gives a thin film whose surface free energy is lower than that of the first polymer, and specifically, the same as the first polymer. And compound (I) and compound (I
Polyamic acid (hereinafter also referred to as “polymer C”) obtained by reacting with I) and a polymer having a structure obtained by dehydrating and ring-closing this polymer C (hereinafter also referred to as “polymer D”).
It is at least one polymer selected from

Therefore, the first polymer and the second polymer are
Although the substances belong to the same system, they are formed relatively by selecting a specific kind of compound used as at least one or both of compound (I) and compound (II). These are two types of polymers that produce different surface free energies of thin films.

<Compound (I)> Specific examples of the tetracarboxylic dianhydride of the compound (I) include, for example, butanetetracarboxylic dianhydride and 1,2,3,4-cyclobutanetetracarboxylic dianhydride. , 1,2,3,4-Cyclopentanetetracarboxylic acid dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, tetracyclo [6.2.1.1.0 ^2,7 ] dodeca-4 , 5, 9, 10
-Tetracarboxylic acid dianhydride, 3,5,6-tricarboxynorbornane-2-acetic acid 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, 5- (2
5-dioxotetrahydrofural) -3-methyl-3-
Cyclohexene-1,2-dicarboxylic acid dianhydride, bicyclo [2.2.2] oct-7-ene-2,3,5,6
-Tetracarboxylic dianhydride, 1,3-dimethyl-1,
2,3,4-cyclobutanetetracarboxylic dianhydride,
1,3-Dichloro-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3 ′, 4,4′-dicyclohexyltetra Carboxylic dianhydride, 3,5,6
-Tricarboxynorbornane-2-acetic acid dianhydride,
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-
Aliphatic or cycloaliphatic tetracarboxylic dianhydrides such as 1,3-dione;

Pyromellitic dianhydride, 3,3 ', 4
4'-benzophenone tetracarboxylic dianhydride, 3,
3 ', 4,4'-biphenylsulfone tetracarboxylic dianhydride, 1,4,5,8-naphthalene tetracarboxylic dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 3 , 3 ', 4,4'-biphenyl ether tetracarboxylic acid dianhydride, 3,3', 4,4'-dimethyldiphenylsilane tetracarboxylic acid dianhydride,
3,3 ′, 4,4′-tetraphenylsilane tetracarboxylic dianhydride, 1,2,3,4-furan tetracarboxylic 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, 3,4
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'-diphenylether dianhydride, bis (tri Phenylphthalic acid) -4,4'-diphenylmethane dianhydride, ethylene glycol-bis (anhydro trimellitate), propylene glycol-bis (anhydro trimellitate), 1,4-butanediol-bis (anhydro) Trimellitate), 1,6-hexanediol-bis (anhydrotrimellitate),
1,8-Octanediol-bis (anhydrotrimellitate), 2,2-bis (4-hydroxyphenyl) propane-bis (anhydrotrimellitate), 3,6-
Aromatic tetracarboxylic dianhydrides such as bis (anhydrotrimellitate) cholestane and compounds represented by the following formulas (1) to (8); steroid skeleton represented by the following formulas (9) to (12) The tetracarboxylic acid dianhydride having These tetracarboxylic dianhydrides can be used alone or in combination of two or more.

[0011]

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[0012]

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[0013]

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Of these, butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, tetracyclo [6.2] 1.1.1.0
^2,7 ] Dodeca-4,5,9,10-tetracarboxylic dianhydride, 5- (2,5-dioxotetrahydrofural)
-3-Methyl-3-cyclohexene-1,2-dicarboxylic acid dianhydride, 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, pyromellitic dianhydride, 3,3 ′, 4,4′-
Benzophenone tetracarboxylic dianhydride, 3,3 ′,
4,4'-biphenylsulfone tetracarboxylic acid dianhydride, 3,3 ', 4,4'-perfluoroisopropylidene diphthalic acid dianhydride, 3,3', 4,4'-biphenyl tetracarboxylic acid dianhydride Anhydrous, 1,3-dimethyl-1,
2,3,4-cyclobutanetetracarboxylic dianhydride,
1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, Ethylene glycol-bis (anhydrotrimellitate), 3,6-bis (anhydrotrimellitate) cholestane and 1,4,5,8-naphthalenetetracarboxylic dianhydride are liquid crystals obtained by using these. The liquid crystal alignment film formed of the aligning agent is preferable because it has a good liquid crystal alignment property for a long period of time.

Furthermore, butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, tetracyclo [6.2.1] .1.0 ^2,7 ]
Dodeca-4,5,9,10-tetracarboxylic dianhydride, 5- (2,5-dioxotetrahydrofural) -3
-Methyl-3-cyclohexene-1,2-dicarboxylic acid 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-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3,3a, 4,5,9
b-hexahydro-8-methyl-5- (tetrahydro-
2,5-Dioxo-3-furanyl) -naphtho [1,2-
c] Furan-1,3-dione and 3,6-bis (anhydrotrimellitate) cholestane have excellent storage stability without deterioration of the liquid crystal aligning agent obtained by using them. It is particularly preferable in that it can be obtained.

<Compound (II)> Specific examples of the diamine compound of the compound (II) include p-phenylenediamine and m.
-Phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylethane, 4,
4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 3,5-diamino-3'-trifluoromethylbenzanilide, 3,5-diamino-
4'-trifluoromethylbenzanilide, 3,3'-
Dimethyl-4,4'-diaminobiphenyl, 4,4'-
Diaminobenzanilide, 4,4'-diaminodiphenyl ether, 1,5-diaminonaphthalene, 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, 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, 4,
4 '-(p-phenylene isopropylidene) bisaniline, 4,4'-(m-phenylene isopropylidene) bisaniline, 2,2-bis [4- (4-amino-2-trifluoromethylphenoxy) phenyl] hexafluoro Propane, 4,4'-diamino-2,2'-bis (trifluoromethyl) biphenyl, 4,4'-bis [(4
-Amino-2-trifluoromethyl) phenoxy] -octafluorobiphenyl, bis (4-aminophenoxy) -2,2'-dimethylpropane, 5-amino-1-
(4'-aminophenyl) -1,3,3-trimethylindane, 6-amino-1- (4'-aminophenyl)-
1,3,3-Trimethylindane, 3,5-diamino-
Aromatic diamine compounds such as 4'-trifluoromethylbenzoanilide and 3,5-diamino-3'-trifluoromethylbenzoanilide;

Two amino groups (-) attached to the aromatic ring
NH ₂ ) and an aromatic diamine compound having a hetero atom other than the nitrogen atom of the amino group; 1,1-metaxylylenediamine, 1,2-ethylenediamine, 1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,3-diaminocyclohexane, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, 4,4-diamino Heptamethylenediamine, 1,4-diaminocyclohexane, isophoronediamine, tetrahydrodicyclopentadienylenediamine, hexahydro-4,7-methanoindanylenemethylenediamine, tricyclo [6.2.1.0 ^2,7 ] undecylene Dimethyldia Emissions, 4,4'-methylenebis aliphatic or cycloaliphatic diamine compounds such as (cyclohexylamine); and di-amino organosiloxane represented by the following formula (13).

[0018]

[Chemical 4]

[In the formula, R ¹ is a hydrocarbon group having 1 to 12 carbon atoms such as an alkyl group such as a methyl group, an ethyl group, a propyl group, a cycloalkyl group such as a cyclohexyl group, or an aryl group such as a phenyl group. Show. p is an integer of 1 to 3, q is an integer of 1 to 20, and r is an integer of 1 to 3. ]

The preferred aromatic diamine compound having _two amino groups (—NH ₂ ) bonded to the aromatic ring and a hetero atom other than the nitrogen atom of the amino group is represented by the following formula (14). And the compound represented by the formula (15).

[0021]

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[In the formula, R ² is a trivalent organic group having a benzene ring, R ³ is —O—, —C (═O) O—, —OC (=
O) -, - C (= O) NH -, - NHC (= O) - organic group, R ⁴ is selected from represents a steroid radical. Specific examples of the diamine compound represented by the formula (14) include cholesteryl 3,5-diaminobenzoate (the structural formula thereof is shown below as compound A01) and the like.

[0023]

[Chemical 6]

[Wherein, R ² is a trivalent organic group having a benzene ring, R ³ is —O—, —C (═O) O—, —OC (=
O) -, - C (= O) NH -, - NHC (= O) - organic group selected from, R ⁵ is a straight and / or branched hydrocarbon group having 1 to 20 carbon atoms. ] Specific examples of the diamine compound represented by the formula (15) include n-dodecyl 3,5-diaminobenzoate.

Further, as the preferred specific examples of the aromatic diamine compound having a hetero atom, including the compounds represented by the formula (14) or the formula (15), those shown below as the compound A01 to the compound A13 are shown. Can be mentioned.

[0026]

[Chemical 7]

[0027]

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[0028]

[Chemical 9]

[0029]

[Chemical 10]

These diamine compounds can be used alone or in combination of two or more kinds. Also,
As these diamine compounds, commercially available products may be used as they are, or commercially available products may be re-reduced before use.

Among these, p-phenylenediamine, 4,4'-diaminodiphenylmethane, 1,5-diaminonaphthalene, 2,7-diaminofluorene, 4,
4'-diaminodiphenyl ether, 4,4 '-(m-
Phenylenediisopropylidene) bisaniline, 4,
4 '-(p-phenylenediisopropylidene) bisaniline, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 9,9-bis (4-aminophenyl) propane, 4,4'-diamino Benzanilide,
2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 2,2-bis [4- (4-amino-2-) Trifluoromethylphenoxy) phenyl] hexafluoropropane, 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl, 4,4′-bis [(4-amino-2-trifluoromethyl) phenoxy ] -Octafluorobiphenyl,
3,5-Diamino-4′-trifluoromethylbenzanilide, as well as compound A01, compound A06 (each of amino groups bound to the para position of the aromatic ring), compound A0
8 (of para-substitution product in which b is 1 or 2), 3, 5
-N-dodecyl diaminobenzoate and compound A13
(A compound in which a trifluoromethyl group is bonded to the para position of the aromatic ring) is used because the liquid crystal alignment film formed by the liquid crystal alignment agent obtained using these will have good liquid crystal alignment properties for a long period of time. ,preferable. In particular, p-
Phenylenediamine, 4,4′-diaminodiphenylmethane, compound A01, compound A06, compound A08,
N-Dodecyl 3,5-diaminobenzoate, 4,4'-diaminobenzanilide, 4,4 '-(p-phenylenediisopropylidene) bisaniline and compound A13
(A trifluoromethyl group bonded to the para position of the aromatic ring) is particularly preferable.

<Proportion of Compound (I) and Compound (II) Used> The proportion of compound (I) and compound (II) used in the synthetic reaction for obtaining polymer A and polymer C is The acid anhydride group contained in the tetracarboxylic dianhydride is 0.2 to 2 relative to 1 equivalent of the amino group contained in the compound.
The ratio is preferably an equivalent ratio, more preferably 0.3 to 1.4 equivalents. When the ratio of the acid anhydride group contained in the tetracarboxylic dianhydride is less than 0.2 equivalents or exceeds 2 equivalents, both are
The resulting polymer A or polymer C does not have a sufficiently large molecular weight, so that the liquid crystal aligning agent obtained has poor coatability.

<Synthesis of Polymer A and Polymer C> Each of Polymer A and Polymer C constituting the liquid crystal aligning agent of the present invention comprises a compound (I) and a compound (II). It is synthesized by a reaction. This reaction is generally 0 to 150 ° C., preferably 0 to 10 in an organic solvent.
It is carried out under a temperature condition of 0 ° C. If the reaction temperature is 0 ° C. or lower, the solubility of the reaction raw material compound in the solvent will be poor, while if it exceeds 150 ° C., the resulting polymer will have a low molecular weight.

The organic solvent used in the synthesis of the polymer A or the polymer C can dissolve the tetracarboxylic dianhydride and the diamine compound which are the reaction raw materials, and the polymer A or the polymer C produced by the reaction. There is no particular limitation as long as it is one. Specifically, for example, γ-butyrolactone,
Non-proton such as N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, tetramethylurea, hexamethylphosphotriamide, 1,3-dimethyl-2-imidazolidinone Examples of polar solvents include phenolic solvents such as m-cresol, xylenol, phenol and halogenated phenols.

The amount (a) of the organic solvent used is such that the total amount (b) of the tetracarboxylic dianhydride and the diamine compound, which are reaction raw materials, is 0.1 to the total amount (a + b) of the reaction solution. The proportion is preferably 30% by weight.

Examples of the above-mentioned organic solvent include alcohols, ketones, esters, ethers, halogenated hydrocarbons, hydrocarbons, etc., which are poor solvents for the polymer A or polymer C produced. It can be added within a range in which the polymer A or the polymer C to be formed does not precipitate.

Specific examples of the poor solvent include methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, ethylene glycol monomethyl ether, acetone and methyl ethyl ketone. , Methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, diethyl oxalate, diethyl malonate, diethyl ether, ethylene glycol ethyl 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 monobutyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, ethylene glycol methyl ether acetate, 4-hydroxy-4-methyl-2-pentanone, ethyl 2-hydroxypropionate, 2-hydroxy-2- Ethyl methylpropionate, methyl 2-hydroxy-2-methylpropionate,
Ethyl ethoxy acetate, ethyl hydroxy acetate, methyl 2-hydroxy-3-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, 3
-Ethyl ethoxypropionate, methyl 3-ethoxypropionate, tetrahydrofuran, dichloromethane,
1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene, hexane, heptane, octane, benzene, toluene, xylene, ethylene glycol monophenyl ether, diethylene glycol monophenyl ether, ethylene glycol methyl Phenyl ether, ethylene glycol ethyl phenyl ether, diethylene glycol methyl phenyl ether, diethylene glycol ethyl phenyl ether, 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-
Methoxybutanol, 2-ethyl-2-ethoxybutanol and the like can be mentioned.

By the above synthetic reaction, a solution in which the polymer A or the polymer C is dissolved can be obtained. Therefore,
The target polymer A or polymer C is obtained by pouring the solution of this polymer into a large amount of a poor solvent to obtain a precipitate, and drying the precipitate under reduced pressure. The polymer A or the polymer C can be purified by dissolving it in an appropriate organic solvent and then performing the step of precipitating with a poor solvent once or several times.

<Polymer B and Polymer D> Polymer B and polymer D constituting the liquid crystal aligning agent of the present invention can be prepared by the following methods (1) to (3), respectively, and usually, Polyimide or polyisoimide.

Method (1): A method of heating polymer A or polymer C for dehydration ring closure (hereinafter also referred to as "imidization"). The reaction temperature in this method is usually 60 to 250.
C, preferably 100 to 170C. Temperature is 60 ℃
When the temperature is less than the above range, imidization does not proceed sufficiently, and when the temperature exceeds 200 ° C., the obtained polymer B or polymer D may have a small molecular weight.

Method (2): A method in which the polymer A or the polymer C is dissolved in an organic solvent, a dehydrating agent and an imidization catalyst are added to this solution, and heating is carried out if necessary. In this method, as the dehydrating agent, acid anhydrides such as acetic anhydride, 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 polymer A or the polymer C. Further, as the imidization catalyst, for example, tertiary amines such as pyridine, collidine, lutidine, and triethylamine can be used, but the imidization catalyst is not limited thereto. The use ratio of the imidization catalyst is preferably 0.5 to 10 moles based on 1 mole of the dehydrating agent used. Examples of the organic solvent used for imidization include the organic solvents exemplified as those used for synthesizing the polymer A or the polymer C. The imidization temperature is usually 0 to 180 ° C, preferably 60 to 150 ° C.

Method (3): A method in which the compound (I) and a diisocyanate compound are mixed and heated if necessary to cause condensation. Specific examples of the diisocyanate compound used in this method include aliphatic diisocyanate compounds such as hexamethylene diisocyanate; alicyclic diisocyanate compounds such as cyclohexane diisocyanate; diphenylmethane-4,4'-diisocyanate and diphenylether-4,4'-. Diisocyanate, diphenylsulfone-4,4'-diisocyanate, diphenylsulfide-4,4'-diisocyanate, 1,2-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-4,4'-
Diisocyanate, N-phenylbenzoic acid amide-4,
Mention may be made of aromatic diisocyanate compounds such as 4'-diisocyanate, which alone or
A combination of two or more species can be used. A catalyst is not particularly required for this method, and the reaction temperature is usually 50
-200 degreeC, Preferably it is 100-160 degreeC. The solution of the polymer B or the polymer D obtained by the above methods (1) to (3) is subjected to the same operation as in the purification method of the polymer A or the polymer C to give the polymer B or the polymer D. Can be purified.

<End Modified Polymer> The polymer A, the polymer B, the polymer C and the polymer D which constitute the liquid crystal aligning agent of the present invention may each be a terminal modified polymer. . Since this terminal-modified polymer has a controlled molecular weight, a liquid crystal aligning agent having better coating properties can be obtained. The terminal-modified polymer can be obtained by adding an acid anhydride, a monoamine compound and a monoisocyanate compound to the reaction system in the synthesis reaction of the polymer A or the polymer C.

Examples of the acid anhydride for terminal modification include maleic anhydride, phthalic anhydride, itaconic anhydride, n-decylsuccinic anhydride, n-dodecylsuccinic anhydride, and n-tetradecylsuccinic anhydride. Acid anhydride, n
-Hexadecyl succinic anhydride and the like can be mentioned. Examples of the monoamine compound for terminal modification include 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 and the like can be mentioned. . Further, examples of the monoisocyanate compound for terminal modification include phenyl isocyanate and naphthyl isocyanate.

<Logarithmic Viscosity of Polymer> The polymer A, the polymer B, the polymer C and the polymer D used in the present invention have a logarithmic viscosity η _ln of preferably 0.05 to 10 dl /
g, more preferably 0.05 to 5 dl / g. Here, the value of the logarithmic viscosity η _ln of each polymer is 30 for a solution in which N-methyl-2-pyrrolidone is used as a solvent and the concentration of the polymer is 0.5 g / 100 ml.
The viscosity is measured at ° C and is calculated by the following mathematical formula.

[0046]

[Equation 1]

<Liquid Crystal Aligning Agent> The liquid crystal aligning agent of the present invention comprises a first polymer comprising polymer A and / or polymer B and a second polymer comprising polymer C and / or polymer D. And are dissolved in an organic solvent. The first polymer gives a thin film having a high surface free energy, and specifically, it is preferably a polymer giving a thin film having a surface free energy of 42 dyn / cm or more. The second polymer gives a thin film having a lower surface free energy than the first polymer, and more specifically, a polymer giving a thin film having a surface free energy of 40 dyn / cm or less. Is preferred.

Even when two kinds of polymers giving thin films having different surface free energies are used, when a combination of polymers is used so that the surface free energy of a thin film having a higher surface free energy is less than 42 dyn / cm. However, the obtained liquid crystal aligning agent is likely to foam, and it may be difficult to form a thin film having a highly uniform film thickness. On the other hand, it gives thin films with different surface free energy. 2
Even in the case of a polymer of a kind, when a combination of polymers having a surface free energy of 40 dyn / cm or more of a thin film having a lower surface free energy is used, for example, a thin film having high uniformity is formed by a printing method. It may be difficult to form.

The liquid crystal aligning agent of the present invention containing the above-mentioned first polymer and second polymer has a surface free energy of more than 38 dyn / cm and 60 dyn / cm.
The following thin film is given, preferably 40 dyn
/ Cm or more and 58 dyn / cm or less. When the liquid crystal aligning agent provides a thin film having a surface free energy of 38 dyn / cm or less, it easily foams, which may make it difficult to form a thin film having a high film thickness uniformity. On the other hand, the liquid crystal aligning agent
When a thin film having a surface free energy of more than 60 dyn / cm is provided, it may be difficult to form a thin film having high uniformity by, for example, a printing method.

In the liquid crystal aligning agent of the present invention, the amount of the second polymer used is, for example, 0.01 to 5 parts by weight based on 100 parts by weight of the first polymer. If the amount of the second polymer used is less than 0.01 part by weight, the thin film to be formed will have insufficient thickness uniformity, while if it exceeds 5 parts by weight, the liquid crystal aligning agent will be insufficient. Since the liquid crystal aligning agent is likely to foam in a printing machine or the like for applying the method, it may be difficult to form a thin film having a high film thickness uniformity in this case as well. Then, by adjusting the ratio of the second polymer to the first polymer, the magnitude of the surface free energy of the thin film formed by the liquid crystal aligning agent can be adjusted within a certain range.

As the organic solvent for dissolving the first polymer and the second polymer, aprotic polar solvents, phenolic solvents, etc. exemplified as those used in the synthesis reaction of the polymer A or the polymer C, etc. Can be mentioned.
Further, the poor solvent exemplified as the one that can be used together in the reaction of synthesizing the polymer A or the polymer C can also be appropriately selected and used together. The concentration of the liquid crystal aligning agent of the present invention is preferably 0.1 to 20% by weight in terms of the solid content of the first polymer and the second polymer.

The liquid crystal aligning agent of the present invention contains the first polymer and the second polymer, and in order to improve the properties of itself or the properties of the liquid crystal alignment film formed therefrom. Can contain various additives. As such an additive, for example, a functional silane-containing compound can be contained for the purpose of improving the adhesiveness of the liquid crystal alignment film to the surface of the substrate constituting the liquid crystal display element.

Examples of such a functional silane-containing compound include 3-aminopropyltrimethoxysilane and 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 like can be mentioned. Furthermore, a reaction product of a tetracarboxylic dianhydride and an amino group-containing silane compound described in JP-A-63-291922 may be contained.

An epoxy compound may be added to improve the peeling property during rubbing when forming the liquid crystal alignment film. Examples of the epoxy compound include bisphenol A type epoxy compound, bisphenol F type epoxy compound, bisphenol AD type epoxy compound, phenol novolac type epoxy compound, cresol novolac type epoxy compound, cyclic aliphatic epoxy compound, aliphatic epoxy compound, glycidyl ester. Examples thereof include epoxy compounds, glycidylamine epoxy compounds, and heterocyclic epoxy compounds. Examples of commercially available bisphenol A type epoxy compounds include Epicoat 1001, 1002, 1003 and 10
04, same 1007, same 1009, same 1010, same 828
(Yukaka Shell Epoxy Co., Ltd.); Examples of commercially available bisphenol F-type epoxy compounds include Epicoat 8
07 (produced by Yuka Shell Epoxy Co., Ltd.); commercially available phenol novolac type epoxy compounds include, for example, Epicoat 152 and 154 (Okaka Shell Epoxy Co., Ltd.).
Manufactured), EPPN-201, 202 (Nippon Kayaku Co., Ltd.)
Commercially available products of cresol novolac type epoxy compounds include, for example, EOCN-102S, 103S, 104S, 1020, 1025, 1027 (manufactured by Nippon Kayaku Co., Ltd.); Epicoat 180S75 (Okaka Shell) Epoxy Co., Ltd.); as commercial products of cycloaliphatic epoxy compounds, for example, CY-175, 177, and 17
9 (manufactured by CIBA-GEIGY), ERL-4234,
No. 4299, No. 4221, No. 4206 (manufactured by U.C.C.), Epolite 4000 (manufactured by Kyoeisha Chemical Co., Ltd.), Epolide GT403 (manufactured by Daicel Chemical Industries, Ltd.); as commercial products of aliphatic epoxy compounds Is, for example, Epolite 40E, 400E, 1600 (Kyoeisha Chemical Co., Ltd.)
Examples of commercially available glycidyl ester-based epoxy compounds include Shodyne 508 (Showa Denko KK).
Manufactured), Araldite CY-182, 192, 184
(Manufactured by CIBA-GEIGY), Epicron 200, and 400 (manufactured by Dainippon Ink and Chemicals, Inc.), Epicoat 871,
872 (produced by Yuka Shell Epoxy Co., Ltd.), ED-56
61, 5662 (Ceraneze Coating Co., Ltd.)
As a glycidyl amine epoxy compound, for example, tetraglycidyl diaminodiphenylmethane, triglycidyl-para-aminophenol, triglycidyl-meta-aminophenol, diglycidyl aniline, diglycidyl toluidine, tetraglycidyl metaxylylenediamine, diglycidyl. Examples of commercial products of tribromoaniline, tetraglycidylbisaminomethylcyclohexane; heterocyclic epoxy compounds include Araldite PT810 (manufactured by CIBA-GEIGY), Epicoat RXE-15 (manufactured by Yuka Shell Epoxy Co., Ltd.), EPI.
TEC (manufactured by Nissan Kagaku Co., Ltd.) and the like.

Other epoxy compounds include, for example, glycidyl acrylate, glycidyl methacrylate, α-
Glycidyl ethyl acrylate, glycidyl α-n-propyl acrylate, glycidyl α-n-butyl acrylate, 3,4-epoxybutyl acrylate, 3,4-epoxybutyl methacrylate, -6,7-acrylic acid Epoxyheptyl, methacrylic acid-6,7-epoxyheptyl, α-ethylacrylic acid-6,7-epoxyheptyl, N- [4- (2,3-epoxypropoxy) -3,
5-dimethylbenzyl] acrylamide, N- [4-
Examples thereof include (co) polymers of an epoxy group-containing radically polymerizable compound such as (2,3-epoxypropoxy) -3,5-dimethylphenylpropyl] acrylamide. These may be used alone or in combination of two or more.

Further, a co-catalyst which enhances the effect of the epoxy compound may be added. Examples of the promoter include pyrrole, imidazole, pyrazole, pyridine, pyrazine, pyrimidine, indole, indazole, benzimidazole and isocyanuric acid. Among these, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-heptadecylimidazole, 4-methyl-2-phenylimidazole, 1
-Benzyl-2-methylimidazole, 2-ethyl-4
-Methyl-1- (2'-cyanoethyl) imidazole,
2-ethyl-4-methyl-1- [2 '-(3 ", 5"-
Imidazole derivatives such as diaminotriazinyl) ethyl] imidazole and benzimidazole are preferred.
These cocatalysts can be used alone or in combination of two or more.

<Production of Liquid Crystal Display Device> According to the liquid crystal aligning agent of the present invention, a liquid crystal alignment film is formed by the following method, for example, and a liquid crystal display device is produced.

(1) A liquid crystal aligning agent is applied to one surface of a substrate for a liquid crystal display element provided with a transparent conductive film, and the applied surface is heated to form a thin film which is a material for the liquid crystal aligning film. . Here, as the substrate, for example, a glass such as float glass or soda glass; a transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone or polycarbonate can be used.

As the transparent conductive film provided on one surface of the substrate, a NESA film made of tin oxide (SnO ₂ ) (US P
PG registered trademark), indium oxide-tin oxide (In ₂
An ITO film made of O ₃ —SnO ₂ ) or the like can be used, and a photoetching method or a method using a mask in advance is used for patterning these transparent conductive films. As a method for applying the liquid crystal aligning agent, a method such as a roll coater method, a spinner method, a curtain coating method, etc. can be used in addition to the printing method.

In applying the liquid crystal aligning agent, a functional silane-containing compound, a functional titanium compound, etc. are provided on one surface of the substrate and the transparent conductive film in order to further improve the adhesion to the substrate surface and the transparent conductive film. It can also be applied in advance. Further, the drying or heating temperature of the coated surface is 80 to
The temperature is set to 200 ° C, preferably 120 to 200 ° C. The dry film thickness of the formed thin film is usually 0.00
1 to 1 μm, preferably 0.005 to 0.5 μm
Is.

(2) The formed thin film is subjected to orientation treatment. This orientation treatment includes rubbing treatment in which the surface of the thin film is rubbed in a certain direction with a roll wound with a cloth made of nylon, rayon, cotton, etc., irradiation with radiation such as ultraviolet rays, uniaxial stretching, Langmuir-Blodgett It is carried out by a method of obtaining a thin film by a method. By this alignment treatment, the thin film is provided with alignment ability for liquid crystal molecules to form a liquid crystal alignment film. Further, the thin film or the liquid crystal alignment film formed by the liquid crystal aligning agent of the present invention may be irradiated with ultraviolet rays as disclosed in, for example, JP-A-6-222366 or JP-A-6-281937. A treatment for changing the pretilt angle, or a method for partially changing the rubbing direction of the liquid crystal alignment film by partially applying a resist on the liquid crystal alignment film, as shown in JP-A-5-107544. By performing various kinds of processing, it is possible to improve the visual characteristics of the liquid crystal display element.

(3) Two substrates having the liquid crystal alignment film formed as described above are prepared, and the two substrates are so arranged that the rubbing directions of the respective liquid crystal alignment films are orthogonal, parallel or antiparallel. , Facing each other with a gap (cell gap) in between, the peripheral portions of the two substrates are bonded together with a sealant, and liquid crystal is injected and filled into the cell gap defined by the substrate surface and the sealant. 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 of the substrates constituting the liquid crystal cell so that the polarization direction thereof is the same as or orthogonal to the rubbing direction of the liquid crystal alignment film formed on the one surface of the substrate. A liquid crystal display device can be obtained by bonding to. Here, as the sealant, for example, a curing agent and an epoxy resin containing aluminum oxide spheres as a spacer can be used.

Examples of the liquid crystal material include nematic type liquid crystals and smectic type liquid crystals. Among them, nematic type liquid crystals are preferable, for example, Schiff base type liquid crystals, azoxy type liquid crystals, biphenyl type liquid crystals, phenylcyclohexane type liquid crystals, ester type liquid crystals. A terphenyl liquid crystal, a biphenyl cyclohexane liquid crystal, a pyrimidine liquid crystal, a dioxane liquid crystal, a bicyclo octane liquid crystal, a cubane liquid crystal, or the like can be used. Further, a ferroelectric liquid crystal such as p-decyloxybenzylidene-p-amino-2-methylbutyl cinnamate can also be used.

In addition to these liquid crystals, cholesteric liquid crystals such as cholesteryl chloride, cholesteryl nonaate, cholesteryl carbonate, etc.
-15 "and" CB-15 "(manufactured by Merck & Co., Inc.) can also be used by adding a chiral agent and the like. As a polarizing plate to be attached to the outer surface of a liquid crystal cell, a polarizing film in which a polarizing film called an H film that absorbs iodine while sandwiching and aligning polyvinyl alcohol is sandwiched between cellulose acetate protective films or the H film itself is used. A polarizing plate can be mentioned.

The alignment film forming agent of the present invention can be used not only for liquid crystal alignment films for TN type liquid crystal display elements but also for STN (Super).
It can also be particularly suitably used for forming a liquid crystal alignment film for an STN liquid crystal display device having a Twisted Nematic liquid crystal cell. Further, the liquid crystal display device provided with the liquid crystal alignment film formed of the liquid crystal aligning agent of the present invention can be selected by selecting the type of the liquid crystal material to be injected and filled between the substrates so that the SH (Super Homeotrope)
ic) type liquid crystal display device, ferroelectric liquid crystal display device, antiferroelectric liquid crystal display device and the like can be suitably used. Furthermore, the liquid crystal display device provided with the liquid crystal alignment film formed of the liquid crystal aligning agent of the present invention has excellent liquid crystal alignment and reliability, and can be effectively used in various devices. For example, desktop calculators and wrist watches. It is preferably used as a display device for a table clock, a counting display board, a word processor, a personal computer, a liquid crystal television, and the like.

The preferred embodiments of the present invention are as follows. (1) The first polymer has a surface free energy of 42 dy.
The liquid crystal aligning agent according to claim 1, which is a polymer that gives a thin film of n / cm or more, and the second polymer is a polymer that gives a thin film having a surface free energy of 40 dyn / cm or less. (2) Surface free energy is 40 dyn / cm or more, 5
The liquid crystal aligning agent according to claim 1, wherein a thin film having a thickness of 8 dyn / cm or less is formed. (3) The ratio of the second polymer with respect to 100 parts by weight of the first polymer is 0.01 to 5 parts by weight, and the method according to claim 1 or the above aspect (1) or (2). Liquid crystal aligning agent. (4) The ratio of the second polymer to 100 parts by weight of the first polymer is 0.1 to 5 parts by weight, and the method according to claim 1 or the above aspect (1) or (2). Liquid crystal aligning agent.

[0067]

EXAMPLES Examples of the present invention will be described in more detail below, but the present invention is not limited thereto. Further, the state of the film thickness and the surface free energy of the thin film formed by the liquid crystal aligning agent according to the examples and comparative examples, and the liquid crystal alignment of the liquid crystal display device including the liquid crystal aligning film formed by the liquid crystal aligning agent. The method of measuring or evaluating the property and the voltage holding ratio is as follows.

[Uniformity of Thin Film Thickness] Using a stylus type film thickness meter, the average film thickness value of the thin film and the difference between the maximum film thickness value and the minimum film thickness value "Difference".) Was measured. [Liquid Crystal Alignment] The presence or absence of an abnormal domain in the liquid crystal cell when the voltage was turned on and off was observed with a polarizing microscope, and when there was no abnormal domain, it was judged as “good” and when there was it as “poor”.

[Voltage Holding Rate] The liquid crystal display element was left for 1 month in a constant temperature bath at 60 ° C., and the voltage holding rate of the liquid crystal display element after standing was “VHR-1” (manufactured by Toyo Technica),
The voltage holding ratio at a frame period of 16.7 msec was measured.

[Surface Free Energy] Reference "JOURN
AL OF APPLIED POLYMER SCI
ENCE VOL. 13, PP. 1741-1747
(1969) ”, D. K. OWENS
According to these methods, it was determined as follows from the contact angle of pure water and the contact angle of methylene iodide on the thin film.

In a system in which a liquid is in contact with the surface of a solid, the relationship between the surface free energy (also called surface tension) of the liquid, the surface free energy of the solid, and the contact angle is expressed by the following equation (1). It is represented by.

[Equation 2]

Here, γ _L ; surface free energy of liquid γ _L ^d ; dispersion component of surface free energy of liquid γ _L ^p ; polar component of surface free energy of liquid γ _S ^d ; dispersion component of surface free energy of solid γ _S ^p ; Polar component of solid surface free energy θ; Contact angle

Thus, at 20 ° C., for pure water, γ _L = 72.8, γ _L ^d = 21.8 and γ _L ^p =
51.0 (in dyn / cm) and for methylene iodide, γ _L = 50.8, γ _L ^d = 49.5 and γ _L ^p = 1.3. By substituting these values into the formula (1), the following formula (2) is obtained in the case of pure water, and the formula (3) is obtained in the case of methylene iodide. Here, θ ₁ and θ ₂ are the contact angles of pure water and methylene iodide, respectively.

[0074]

(Equation 3)

Therefore, the measured values of the contact angle are substituted into the equations (2) and (3), γ _S ^d and γ _S ^p are obtained from this simultaneous equation, and the surface freeness of the thin film is calculated by the following equation (4). The energy γ _S was calculated.

[Equation 4]

The contact angle is measured by the contact angle measuring device "CA-
4 microliters of water or methylene iodide was dropped onto the thin film using "A type" (manufactured by Kyowa Interface Science Co., Ltd.), and 1
It was determined by measuring the contact angle after a lapse of minutes.

[Synthesis Example 1] 44.8 g of 2,3,5-tricarboxycyclopentylacetic acid dianhydride and 21.6 g of p-phenylenediamine were dissolved in 988 g of N-methyl-2-pyrrolidone and reacted at room temperature for 6 hours. Let The resulting reaction product solution was poured into a large excess of methyl alcohol to precipitate the reaction product. After that, the precipitate is separated and washed with methyl alcohol, and the mixture is dried under reduced pressure at 40 ° C. for 1 hour.
By drying for 5 hours, the logarithmic viscosity is 1.44 dl /
60.2 g of Polymer (A-1) was obtained. 1 g of this polymer (A-1) was dissolved in 19 g of N-methyl-2-pyrrolidone, and this solution was placed on the surface of the glass substrate for IT.
18 is applied by a printing method on a transparent conductive film made of O.
A thin film was formed by drying at 0 ° C. for 1 hour.
The surface free energy of this thin film was 58 dyn / cm.

[Synthesis Example 2] 30.0 g of the polymer (A-1) obtained in Synthesis Example 1 was dissolved in 570 g of γ-butyrolactone, and 21.6 g of pyridine and 1% of acetic anhydride were added to this solution.
The imidization was performed by adding 6.74 g and reacting at 120 ° C. for 3 hours. Then, precipitation, separation, washing and drying of the reaction product are carried out in the same manner as in Synthesis Example 1,
Polymer (B-1) 24.0 having an inherent viscosity of 1.35 dl / g
g was obtained. The surface free energy of the thin film formed of this polymer (B-1) was 57 dyn / cm.

Synthesis Example 3 Synthesis Example 1 was repeated except that 10.8 g of p-phenylenediamine and 33.4 g of 2,2-bis (4-aminophenyl) hexafluoropropane were used as the diamine compounds. A polymer (A-2) was obtained in the same manner as in Example 1, and this polymer (A-
By imidizing 2) in the same manner as in Synthesis Example 2, a polymer (B-2) having a logarithmic viscosity of 1.06 dl / g.
22.2 g was obtained. The surface free energy of the thin film formed by this polymer (B-2) was 45 dyn / cm.

[Synthesis Example 4] A logarithmic viscosity of 1. was obtained in the same manner as in Synthesis Example 3 except that 39.2 g of cyclobutanetetracarboxylic dianhydride was used as the tetracarboxylic dianhydride. 16 dl / g polymer (A-
3) 79.5 g was obtained. The surface free energy of the thin film formed from this polymer (A-3) was 42 dyn / cm.

Synthesis Example 5 Synthesis Example 1 was repeated except that 20.5 g of p-phenylenediamine and 5.2 g of cholesteryl 3,5-diaminobenzoate were used as the diamine compound. Polymer (A-4)
And further imidizing the polymer (A-4) in the same manner as in Synthesis Example 2 to obtain a logarithmic viscosity of 1.2.
22.2 g of a 2 dl / g polymer (B-4) was obtained. The surface free energy of the thin film formed by this polymer (B-4) is 4
It was 6 dyn / cm.

Synthesis Example 6 Synthesis Example 1 was repeated except that 19.7 g of p-phenylenediamine and 10.4 g of cholesteryl 3,5-diaminobenzoate were used as the diamine compound. Polymer (A-
5) and further imidizing the polymer (A-5) in the same manner as in Synthesis Example 2 to obtain 22.4 g of the polymer (B-5) having a logarithmic viscosity of 1.02 dl / g. Obtained. The surface free energy of the thin film formed by this polymer (B-5) was 42 dyn / cm.

[Synthesis Example 7] In Synthesis Example 5, the tetracarboxylic dianhydride was 1,3,3a, 4,5,9b.
-Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-
Synthesis Example 5 except that 60.0 g of 1,3-dione was used
A polymer (A-6) was obtained in the same manner as above, and the polymer (A-6) was imidized in the same manner as in Synthesis Example 2 to give a polymer having a logarithmic viscosity of 1.06 dl / g. (B
-6) 22.2 g was obtained. The surface free energy of the thin film formed of this polymer (B-6) was 42 dyn / cm.

[Synthesis Example 8] Synthesis Example 1 except that 19.7 g of p-phenylenediamine and 6.5 g of 3,5-diaminobenzoic acid-n-dodecyl were used as the diamine compound in Synthesis Example 1. Similarly, the polymer (A-
7) and further imidizing the polymer (A-7) in the same manner as in Synthesis Example 2 to obtain 24.4 g of a polymer (B-7) having a logarithmic viscosity of 1.01 dl / g. Obtained. The surface free energy of the thin film formed of this polymer (B-7) was 44 dyn / cm.

[Synthesis Example 9] Logarithm was obtained in the same manner as in Synthesis Example 1 except that 17.3 g of p-phenylenediamine and 20.8 g of cholesteryl 3,5-diaminobenzoate were used as the diamine compound. Viscosity 0.98
79.9 g of polymer (C-1) of dl / g was obtained. The surface free energy of the thin film formed by this polymer (C-1) is 39.
It was dyn / cm.

[Synthesis Example 10] The polymer (C-1) obtained in Synthesis Example 9 was imidized in the same manner as in Synthesis Example 2 to give a polymer having a logarithmic viscosity of 0.97 dl / g. 23.2 g of (D-1) was obtained. The surface free energy of the thin film formed by this polymer (D-1) was 38 dyn / cm.

[Synthesis Example 11] A logarithmic viscosity of 1.02 dl / in the same manner as in Synthesis Example 9 except that 39.2 g of cyclobutanetetracarboxylic acid dianhydride was used as the tetracarboxylic acid dianhydride. g of polymer (C-
2) 74.5 g was obtained. The surface free energy of the thin film formed of this polymer (C-2) was 37 dyn / cm.

[Synthesis Example 12] In Synthesis Example 9, the tetracarboxylic dianhydride was 1,3,3a, 4,5,9.
b-Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-
Synthesis Example 9 except that 60.0 g of 1,3-dione was used
A polymer (C-3) was obtained in the same manner as described above, and the polymer (C-3) was imidized in the same manner as in Synthesis Example 2 to give a polymer having a logarithmic viscosity of 0.89 dl / g. (D
-3) 23.2g was obtained. The surface free energy of the thin film formed by this polymer (D-3) was 36 dyn / cm.

[Synthesis Example 13] In Synthesis Example 1, as the diamine compound, 17.3 g of p-phenylenediamine and a diamine compound represented by Compound A05 (each amino group bonded to the para position of the aromatic ring) 25. Polymer (C-in the same manner as in Synthesis Example 1 except that 7 g was used.
4) was obtained, and the polymer (C-4) was further imidized in the same manner as in Synthesis Example 2 to obtain 24.2 g of the polymer (D-4) having a logarithmic viscosity of 0.79 dl / g. Obtained. The surface free energy of the thin film formed from this polymer (D-4) was 33 dyn / cm.

[Synthesis Example 14] In Synthesis Example 1, as the tetracarboxylic acid dianhydride, 3,3 ′, 4,4′-perfluoroisopropylidene diphthalic acid dianhydride 88.8 was used.
g and 2,2-bis (4-aminophenyl) hexafluoropropane (66.8 g) were used, but in the same manner as in Synthesis Example 1, a polymer (C-5) having a logarithmic viscosity of 1.26 dl / g.
140.3 g was obtained. The surface free energy of the thin film formed of this polymer (C-5) was 37 dyn / cm.

[Synthesis Example 15] In Synthesis Example 1, 4,4'-diaminobenzanilide 4 was used as the diamine compound.
86.2 g of a polymer (A-8) having a logarithmic viscosity of 1.22 dl / g was obtained in the same manner as in Synthesis Example 1 except that 5.5 g was used. The surface free energy of the thin film formed of this polymer (A-8) was 60.5 dyn / cm.

[Synthesis Example 16] Synthesis Example 1 was repeated except that 18.1 g of p-phenylenediamine and 14.5 g of cholesteryl 3,5-diaminobenzoate were used as diamine compounds. A polymer (X) was obtained, and the polymer (X) was imidized in the same manner as in Synthesis Example 2 to give a logarithmic viscosity of 0.99 dl.
23.2 g of a polymer (Y) of 1 g / g was obtained. The surface free energy of the thin film formed by this polymer (Y) is 41 dyn /
It was cm.

[Synthesis Example 17] In Synthesis Example 1, the tetracarboxylic dianhydride was 1,3,3a, 4,5,9.
b-hexahydro-8-methyl-5- (tetrahydro-
2,5-Dioxo-3-furanyl) -naphtho [1,2-
c] Furan-1,3-dione (62.9 g) was used as a diamine compound, and 4,4′-diaminophenylmethane 3
A polymer (A-9) was obtained in the same manner as in Synthesis Example 1 except that 9.7 g was used, and the imidization temperature was 80 ° C. with respect to the polymer (A-9). By performing imidization in the same manner as in Synthesis Example 2, a logarithmic viscosity of 0.8
23.5 g of 7 dl / g of polymer (B-9) was obtained. The surface free energy of the thin film formed by this polymer (B-9) is 5
It was 4 dyn / cm.

[Synthesis Example 18] In Synthesis Example 1, as tetracarboxylic dianhydride, 1,3-dimethyl-1,
2,3,4-Cyclobutanetetracarboxylic acid dianhydride 4
Polymer (A-10) 59.6 having a logarithmic viscosity of 0.96 dl / g was prepared in the same manner as in Synthesis Example 1 except that 4.8 g was used.
g was obtained. The surface free energy of the thin film formed by the polymer (A-10) was 57 dyn / cm.

[Synthesis Example 19] In Synthesis Example 9, 3, 5
Instead of cholesteryl diaminobenzoate, compound A1
Polymer (C-6) 7 having a logarithmic viscosity of 0.98 dl / g in the same manner as in Synthesis Example 9 except that 16.9 g of 2 (a trifluoromethyl group bonded to the para position of an aromatic ring) was used.
5.4 g was obtained. The surface free energy of the thin film formed by this polymer (C-6) was 37 dyn / cm.

<Example 1> (1) Preparation of liquid crystal aligning agent: 10.0 g of the polymer (A-1) obtained in Synthesis Example 1 and the polymer (C-1) 0 obtained in Synthesis Example 9 A liquid crystal aligning agent was prepared by dissolving 0.1 g of N-methyl-2-pyrrolidone into a solution having a solid content concentration of 4% by weight, and filtering this solution with a filter having a pore size of 1 μm.

(2) Formation of thin film: This liquid crystal aligning agent was applied on a transparent conductive film made of an ITO film provided on one surface of a glass substrate using a printing device, and dried at 180 ° C. for 1 hour. , A thin film was formed. Regarding the state of the film thickness of this thin film, the average film thickness was 500Å and the maximum difference was 15Å. The surface free energy of this thin film is 56 dyn.
Was / cm.

(3) 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 liquid crystal molecules can be improved. It was applied to a thin film to form a liquid crystal alignment film. Here, the rubbing treatment conditions are: roll rotation speed: 500 rpm, stage movement speed: 1 cm /
The indentation length was 0.4 mm.

(4) Fabrication of liquid crystal display device: Two substrates having a liquid crystal alignment film formed as described above were fabricated, and an epoxy resin containing aluminum oxide spheres with a diameter of 17 μm was formed on the outer edge of each substrate. After being applied by screen printing, two substrates are arranged facing each other with a gap so that the rubbing directions in the respective liquid crystal alignment films are orthogonal to each other, and the outer edges are brought into contact with each other and pressure-bonded to form an adhesive. Was cured. Then, a nematic liquid crystal "MLC-2001" (manufactured by Merck Japan Co., Ltd.) is injected and filled into the cell gap defined by the adhesive on the surface and the outer edge of the substrate, and then the injection hole is filled with an epoxy adhesive. A liquid crystal cell was constructed by sealing. 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 so that the polarization direction matches the rubbing direction of the liquid crystal alignment film formed on the one surface of the substrate. Thus, a liquid crystal display element was produced.

(5) Evaluation of liquid crystal display device: When the liquid crystal display device manufactured as described above was examined for liquid crystal orientation, abnormal domains were observed in the liquid crystal cell when the voltage was turned on and off. However, it was confirmed that it had excellent orientation. In addition, this liquid crystal display device is
The liquid crystal display device was allowed to stand in a constant temperature bath of 0 ° C. for 1 month, and the voltage holding ratio of the liquid crystal display device after the standing was measured to find a high value of 98.3%.

<Examples 2 to 18> According to the formulations shown in Table 1, the polymers A, B, C and D obtained in Synthesis Examples 2-14 and Synthesis Examples 17-19 were prepared. Using each of them, a liquid crystal aligning agent was prepared in the same manner as in Example 1. Then, using each of the liquid crystal aligning agents thus obtained, a liquid crystal display device was produced in the same manner as in Example 1. With respect to each of the obtained liquid crystal aligning agents, the state of the thickness of the thin film and the magnitude of the surface free energy were examined, and with respect to each of the liquid crystal display elements, the liquid crystal orientation and the voltage holding ratio were evaluated. The results are shown in Table 1 together with Example 1.

In Tables 1 and 2, the numbers in parentheses at the top of each column of the first polymer and the second polymer indicate the value of the surface free energy of the thin film formed by only the polymer ( (Unit: dyn / cm), and the numbers in the lower row indicate the usage amount (unit: g) of the polymer. Further, the substances in parentheses in the columns of the first polymer and the second polymer according to Comparative Example 3 and Comparative Example 6 correspond to the first polymer and the second polymer of the present invention. Not a thing.

Comparative Example 1 10 g of the polymer (A-1) obtained in Synthesis Example 1 was dissolved in N-methyl-2-pyrrolidone to prepare a solution having a solid content of 4% by weight. A liquid crystal aligning agent for comparison was prepared in the same manner as in Example 1. Using this liquid crystal aligning agent, a liquid crystal display element was produced in the same manner as in Example 1, and the same evaluation was performed. Table 2 shows the results. In the liquid crystal display device using this liquid crystal aligning agent,
The display unevenness was considered to be due to the non-uniformity of the film thickness of the liquid crystal alignment film.

Comparative Example 2 Only 10.0 g of the polymer (C-1) obtained in Synthesis Example 9 was dissolved in N-methyl-2-pyrrolidone to prepare a solution having a solid content concentration of 4% by weight. A liquid crystal aligning agent for comparison was prepared in the same manner as in Example 1 except for the above. Using this liquid crystal aligning agent, a liquid crystal display element was produced in the same manner as in Example 1, and the same evaluation was performed. Table 2 shows the results. In the liquid crystal display device using this liquid crystal aligning agent, unevenness in the film thickness, which is recognized as being due to foaming of the liquid crystal aligning agent at the time of printing, and display unevenness due to this occurred.

Comparative Example 3 10.0 g of the polymer (Y) obtained in Synthesis Example 16 was dissolved in N-methyl-2-pyrrolidone to prepare a solution having a solid content of 4% by weight. A liquid crystal aligning agent for comparison was prepared in the same manner as in Example 1. Using this liquid crystal aligning agent, a liquid crystal display element was produced in the same manner as in Example 1, and the same evaluation was performed. Table 2 shows the results. In the liquid crystal display device using this liquid crystal aligning agent, display unevenness that is considered to be due to the nonuniformity of the film thickness of the liquid crystal aligning film occurred.

Comparative Example 4 10.0 g of the polymer (C-1) obtained in Synthesis Example 9 and 0.7 g of the polymer (D-4) obtained in Synthesis Example 13 were mixed with N-methyl. A liquid crystal aligning agent for comparison was prepared in the same manner as in Example 1 except that it was dissolved in 2-pyrrolidone to prepare a solution having a solid content concentration of 4% by weight. Using this liquid crystal aligning agent, a liquid crystal display element was produced in the same manner as in Example 1, and the same evaluation was performed. Table 2 shows the results. In the liquid crystal display device using this liquid crystal aligning agent,
The display unevenness was considered to be due to the non-uniformity of the film thickness of the liquid crystal alignment film.

Comparative Example 5 10.0 g of the polymer (A-8) obtained in Synthesis Example 15 and 0.05 g of the polymer (D-3) obtained in Synthesis Example 12 were mixed with N-methyl. A liquid crystal aligning agent for comparison was prepared in the same manner as in Example 1 except that it was dissolved in 2-pyrrolidone to prepare a solution having a solid content concentration of 4% by weight. Using this liquid crystal aligning agent, a liquid crystal display element was produced in the same manner as in Example 1, and the same evaluation was performed. Table 2 shows the results. In the liquid crystal display device using this liquid crystal aligning agent, display unevenness that is considered to be due to the nonuniformity of the film thickness of the liquid crystal aligning film occurred.

Comparative Example 6 10.0 g of the polymer (A-1) obtained in Synthesis Example 1 and 0.1 g of the surfactant "Megafuck F-120" (manufactured by Dainippon Ink and Chemicals, Inc.) were added to N-.
In the same manner as in Example 1 except that the solution was dissolved in methyl-2-pyrrolidone to prepare a solution having a solid content concentration of 4% by weight,
A liquid crystal aligning agent for comparison was prepared. Using this liquid crystal aligning agent, a liquid crystal display element was produced in the same manner as in Example 1, and the same evaluation was performed. Table 2 shows the results. In the liquid crystal display device using this liquid crystal aligning agent, the liquid crystal alignment film had a uniform film thickness, but the voltage holding ratio of the liquid crystal display device was poor.

[0109]

[Table 1]

[0110]

[Table 2]

[0111]

According to the present invention, a liquid crystal alignment film capable of forming a thin film having a high uniformity of film thickness, having a good liquid crystal alignment property, and obtaining a liquid crystal display device having excellent electrical characteristics. It is possible to provide a liquid crystal aligning agent capable of forming.

Front Page Continuation (72) Inventor Ansei Matsuki 2-11-24 Tsukiji, Chuo-ku, Tokyo Within Nippon Synthetic Rubber Co., Ltd.

Claims (1)

[Claims] 1. A first polymer which gives a thin film having a high surface free energy, and a second polymer which gives a thin film having a lower surface free energy than the first polymer. The polymer and the second polymer are both at least one selected from a polyamic acid obtained by reacting a tetracarboxylic dianhydride and a diamine compound and a polymer having a dehydrated and ring-closed structure thereof. , The surface free energy exceeds 38 dyn / cm, 60d
A liquid crystal aligning agent, wherein a thin film of yn / cm or less is formed.