KR101455418B1 - Agent for alignment treatment of liquid crystal and liquid crystal display element using the same - Google Patents

Abstract

Provided is a liquid crystal alignment treatment agent excellent in stability of the pretilt angle, and a liquid crystal display element having less change in the pretilt angle and excellent display reliability. At least one kind of polymer selected from the group consisting of polyamide acid and polyimide, and a crosslinkable compound having at least two oxetane groups represented by the following formula {I} in the molecule.

Description

TECHNICAL FIELD [0001] The present invention relates to a liquid crystal alignment treatment agent and a liquid crystal display device using the same. BACKGROUND ART < RTI ID = 0.0 >

The present invention relates to a liquid crystal alignment treatment agent used for production of a liquid crystal alignment film, and a liquid crystal display device using the same.

In a liquid crystal display element, a liquid crystal alignment film serves to align the liquid crystal in a certain direction. Presently, the main liquid crystal alignment film which is industrially used is produced by applying a polyimide-based liquid crystal alignment treatment agent composed of a solution of polyamic acid or polyimide which is a polyimide precursor to a substrate to form a film, Is subjected to a surface stretching treatment by rubbing after the film is formed. A method of using an anisotropic photochemical reaction by polarized ultraviolet irradiation or the like has been proposed as an alternative to the rubbing treatment, and studies for industrialization have been conducted recently.

The liquid crystal alignment film is also used for controlling the angle of the liquid crystal with respect to the substrate, that is, the control of the pretilt angle of the liquid crystal. However, while the liquid crystal display device has high performance and its use range is expanding year by year, Not only is the stability of the pretilt angle becoming increasingly important.

In view of the stability of the pretilt angle, a compound having two or more epoxy groups in the molecule is contained in the liquid crystal alignment treatment agent of polyimide for the purpose of obtaining a constant pretilt angle in accordance with the rubbing condition in the production process of the liquid crystal alignment film (See, for example, Patent Document 1).

In the manufacturing process of a liquid crystal display element, in order to enhance the alignment uniformity of the liquid crystal, there is a case where the liquid crystal is enclosed and then heat-treated to make the liquid crystal isotropic once. However, when the stability of the pretilt angle is low, there arises a problem that the pretilt angle of the desired size is not obtained after this isotropic process, or a deviation occurs in the pretilt angle. Particularly, in a liquid crystal display element using a backlight having a large heating value to obtain a high luminance or a liquid crystal display element used in a vehicle application, for example, a car navigation system or a meter panel, have. When the pretilt angle is gradually changed under such a severe condition, the initial display characteristic can not be obtained, or the display becomes uneven.

Patent Document 1: JP-A-7-234410

DISCLOSURE OF INVENTION

Problems to be solved by the invention

It is an object of the present invention to provide a liquid crystal alignment treatment agent having an excellent stability of a pretilt angle even under a high temperature environment for a long time and to provide a liquid crystal alignment treatment agent having a small change in the pretilt angle, And to provide a display device.

In addition, as the densification of pixels in a recent liquid crystal display element and the increase in the solidification of the surface structure of the substrate (large unevenness of the surface) increase the variation in the rubbing strength in the liquid crystal display surface compared to the conventional one, , The alignment restraining force of the liquid crystal is weakened, and a partial display defect occurs. Therefore, in the present invention, in addition to improving the stability of the pretilt angle, it is also an object to provide a liquid crystal alignment treatment agent which does not deteriorate the orientation of the liquid crystal even under weak rubbing conditions, that is, not depending on the rubbing condition.

Means for solving the problem

That is, the present invention has the following points.

(1) A liquid crystal alignment treatment agent comprising the following components (A) and (B).

(A) at least one kind of polymer (B) selected from the group consisting of polyamic acid and polyimide;

[Chemical Formula 1]

(2) The liquid crystal alignment treating agent according to (1), wherein the component (B) is a compound represented by the following formula [2].

(2)

(Wherein X ₁ represents N, NH, CO, O, S, SO ₂ , Si, silsesquioxane, polysiloxane or an organic group having 1 to 20 carbon atoms, O, S, SO ₂ , or an organic group having 1 to 20 carbon atoms, and X ₂ and X ₃ each independently represent a single bond, NH, CO, O, S, (N, O, S, Si) may be contained, and Y ₁ and Y ₂ each independently represent an organic group having 1 to 20 carbon atoms. M and n each independently represent an integer of 0 to 20, and m + n represents an integer of 2 to 20,

(3) The liquid crystal alignment treating agent according to (1), wherein component (B) is a compound represented by the following formula [3].

(3)

X ₂ and X ₃ each independently represent a single bond, NH, CO, O, S, SO ₂ or an organic group having 1 to 20 carbon atoms and heteroatoms (N, O , S, and Si), Y ₁ and Y ₂ each independently represent an organic group having 1 to 20 carbon atoms, and the organic group may contain hetero atoms (N, O, S, Si) ₁ is a single _{bond, NH, N (CH 3)} , NHCO, CONH, NHCONH, CO, COO, O, S, SO 2, CF 2, C (CF 3) 2, Si (CH 3) 2, OSi (CH _{3) 2, Si (CH 3} ) 2 O, OSi (CH 3) 2 O, or an alkyl group having a carbon number of 1 to 10, and m, n are each independently an integer of 0 to 10, and m + n is An integer of 2 to 10)

(4) The liquid crystal alignment treating agent according to (1), wherein component (B) is a compound represented by the following formula [4].

[Chemical Formula 4]

(Formula [4] of, X ₁ is _{NH, N (CH 3),} NHCO, CONH, NHCONH, CO, COO, OCO, O, S, SO 2, CF 2, C (CF 3) 2, Si (CH ₃ ) ₂ , OSi (CH ₃ ) ₂ , Si (CH ₃ ) ₂ O, or OSi (CH ₃ ) ₂ O and Y ₁ and Y ₂ each independently represent an alkyl group having 1 to 10 carbon atoms.

(5) The liquid crystal alignment treating agent according to (1), wherein component (B) is a compound represented by the following formula [5].

[Chemical Formula 5]

(In the formula [5], X ₁ is N, an aliphatic ring having 1 to 20 carbon atoms, an aromatic ring having 1 to 20 carbon atoms, or an alkylene having 1 to 20 carbon atoms, Y ₁ and Y ₂ each represent an alkyl group having 1 to 10 carbon atoms M, n is an integer of 0 to 20, and m + n is an integer of 2 to 20)

(6) The liquid crystal alignment treatment agent according to any one of (1) to (5), wherein the content of the component (B) is 0.1 to 150 parts by mass based on 100 parts by mass of the component (A).

(7) The liquid crystal alignment treatment agent according to any one of (1) to (6), further comprising an organic solvent.

(8) The liquid crystal alignment treating agent according to (7), wherein the organic solvent contains 5 to 80 mass% of a solvent having a low surface tension in the total organic solvent.

(9) A liquid crystal alignment film obtained by the liquid crystal alignment treatment agent according to any one of (1) to (8).

(10) A liquid crystal display element having the liquid crystal alignment film according to (9) above.

Effects of the Invention

By using the liquid crystal alignment treatment agent of the present invention, a liquid crystal alignment film excellent in the stability of the pretilt angle can be obtained even under a high temperature environment for a long time, and the liquid crystal display device having this liquid crystal alignment film has excellent reliability. Further, the liquid crystal alignment treatment agent of the present invention is particularly effective in applications requiring rubbing treatment because the stretching property of the polymer by rubbing is hardly inhibited and the orientation of the liquid crystal is not deteriorated even under a weak rubbing condition.

BEST MODE FOR CARRYING OUT THE INVENTION

≪ Component (A): polyamic acid and polyimide >

The liquid crystal alignment treatment agent of the present invention contains at least one polymer selected from the group consisting of polyamic acid and polyimide. The specific structure of the polyamic acid and the polyimide is not particularly limited and may be, for example, a polyamic acid or a polyimide contained in a known liquid crystal alignment treatment agent.

The polyamic acid can be easily obtained by reacting a tetracarboxylic acid or a derivative of a tetracarboxylic acid with a diamine.

The method for producing the polyamic acid and the polyimide as the component (A) used in the present invention is not particularly limited. Generally, a polyamic acid is obtained by reacting a tetracarboxylic acid component composed of one or more tetracarboxylic acids and derivatives thereof with a diamine component composed of one or more kinds of diamine compounds, A method of imidizing a polyamic acid to form a polyimide is used.

At this time, the polyamic acid to be obtained can be a homopolymer (homopolymer) or a copolymer (copolymer) by appropriately selecting the tetracarboxylic acid component and the diamine component as raw materials.

Here, the tetracarboxylic acid and derivatives thereof are tetracarboxylic acid, tetracarboxylic acid dihalide and tetracarboxylic dianhydride. Among them, the tetracarboxylic dianhydride is preferred because of its high reactivity with the diamine compound.

Specific examples include pyromellitic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, 2,3,6,7-anthracene tetracarboxylic acid, 1,2,5,6-anthracene tetracarboxylic acid, 3,3 ', 4,4'-biphenyltetracarboxylic acid, 2,3,3 (3,4-dicarboxyphenyl) ether, 3,3 ', 4,4'-benzophenonetetracarboxylic acid, bis (3,4-dicarboxyphenyl) Bis (3,4-dicarboxyphenyl) propane, 1,1,1,3,3,3-hexafluoro-2,2 (3,4-dicarboxyphenyl) propane, bis (3,4-dicarboxyphenyl) dimethylsilane, bis (3,4-dicarboxyphenyl) diphenylsilane, 2,3,4,5- (3,4-dicarboxyphenoxy) phenyl] propane, 3,3 ', 4,4'-tetramethylpiperidine, 2,2- '-Diphenylsulfone tetracarboxylic acid, 3,4,9,10-perylene tetracarboxylic acid 1,3-diphenyl-1,2,3,4-cyclobutane tetracarboxylic acid, oxydipetetracarboxylic acid, 1,2,3,4-cyclobutanetetracarboxylic acid, 1,2- , 3,4-cyclopentanetetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracar 1,2-dimethyl-1,2,3,4-cyclobutane tetracarboxylic acid, 1,3-dimethyl-1,2,3,4-cyclobutane tetracarboxylic acid, 1,2,3 , 4-cycloheptane tetracarboxylic acid, 2,3,4,5-tetrahydrofuran tetracarboxylic acid, 3,4-dicarboxy-1-cyclohexyl succinic acid, 2,3,5-tricarboxycyclopentyl acetic acid , 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalenesuccinic acid, bicyclo [3,3,0] octane-2,4,6,8-tetracarboxylic acid, [4,3,0] nonane-2,4,7,9-tetracarboxylic acid, bicyclo [4,4,0] decane-2,4,7,9-tetracarboxylic acid, bicyclo [ , 4,0] decane-2,4,8,10-tetracarboxylic acid, tricyclo [6.3.0 2,2,2] oct-7 < 2,6 >] undecane-3,5,9,11-tetracarboxylic acid, 1,2,3,4-butanetetracarboxylic acid, bicyclo [ -En-2,3,5,6-tetracarboxylic acid, tetracyclo [6,2,1,1,0,2,7] dodeca-4,5,9,10-tetracarboxylic acid and the like And tetracarboxylic acid. Further, dihalides of these tetracarboxylic acids and dianhydrides of tetracarboxylic acids and the like can be given.

Particularly, in the use of a liquid crystal alignment film, alicyclic tetracarboxylic acids and their dianhydrides and their dicarboxylic acid dihalides are preferred from the viewpoint of transparency of the coating film (coating film), and 1,2,3,4-cyclobutane Tetracarboxylic acid, 2,3,5-tricarboxycyclopentylacetic acid, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalenesuccinic acid, bicyclo [3,3,0] -2,4,6,8-tetracarboxylic acid, and dihalides of these tetracarboxylic acids, and dianhydrides of tetracarboxylic acids are preferred.

The tetracarboxylic acid and derivatives thereof exemplified above can be used singly or in combination of two or more thereof depending on the properties such as liquid crystal aligning property, voltage holding property, and accumulated charge when the liquid crystal alignment film is used.

The diamine used in the synthesis reaction of the polyamic acid is not particularly limited.

Specific examples include p-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, m- -m-phenylenediamine, 2,5-diaminotoluene, 2,6-diaminotoluene, 2,5-diaminophenol, 2,4-diaminophenol, 3,5-diaminophenol, 3,5 -Diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6-diaminoresorcinol, 4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'- Phenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dihydroxy-4,4'-diaminobiphenyl, 3,3'-dicarboxy-4,4 '-Diaminobiphenyl, 3,3'-difluoro-4,4'-biphenyl, 3,3'-trifluoromethyl-4,4'-diaminobiphenyl, 3,4'- Aminobiphenyl, 3,3'-diaminobiphenyl, 2,2'-diaminobiphenyl, 2,3'-diaminobiphenyl, 4,4'-diaminodiphenylmethane, 3,3'- Diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 2,2'-diaminodiphenylmethane, 2,3'-diaminodiphenylmethane, 4'-diaminodiphenylmethane, , 4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 2,2'-diaminodiphenyl ether, 2,3'-diamino Bis (4-aminophenyl) silane, dimethyl-bis (4-aminophenyl) silane, diphenyl ether, 4,4'-sulfonyl dianiline, 3,3'-sulfonyl dianiline, bis , Dimethyl-bis (3-aminophenyl) silane, 4,4'-thiodianiline, 3,3'-thiodianiline, 4,4'-diaminodiphenylamine, 3,3'-diaminodiphenyl Amine, 3,4'-diaminodiphenylamine, 2,2'-diaminodiphenylamine, 2,3'-diaminodiphenylamine, N-methyl (4,4'-diaminodiphenyl) amine (3,3'-diaminodiphenyl) amine, N-methyl (3,4'-diaminodiphenyl) amine, N-methyl -Methyl (2,3'-diaminodiphenyl) amine, 4,4'-diaminobenzophenone, 3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone, 1,4-di Minonaphthalene, 2,2'-diaminobenzophenone, 2,3'-diamine Diaminonaphthalene, 1,6-diaminonaphthalene, 1,5-diaminonaphthalene, 1,5-diaminonaphthalene, 1,6-diaminonaphthalene, 1,6- Naphthalene, 2,7-diaminonaphthalene, 2,8-diaminonaphthalene, 1,2-bis (4-aminophenyl) Bis (3-aminophenyl) propane, 1,3-bis (3-aminophenyl) propane, 1,4- Bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, ) Benzene, 1,3-bis (4-aminophenyl) benzene, 1,4-bis (4-aminobenzyl) benzene, Phenylenebis (methylene)] dianiline, 4,4 '- [1,3-phenylenebis (methylene)] dianiline, 3,4' - [ Dianiline, 3,4 '- [1,3-phenylenebis (methylene)] dianiline, 3,3' - [1,4-phenylenebis )]] Dianiline, 3,3 '- [1,3-phenylenebis (methylene)] dianiline, 1,4-phenylenebis [ [(3-aminophenyl) methanone], 1,3-phenylenebis [(4-aminophenyl) methanone] Phenylenebis (4-aminobenzoate), 1,3-phenylenebis (3-aminobenzoate), 1,3-phenylenebis Aminophenyl) isophthalate, bis (3-aminophenyl) isophthalate, N, N (3-aminophenyl) terephthalate, bis N, N '- (1,4-phenylene) bis (4-aminobenzamide) (Phenylene) bis (3-aminobenzamide), N, N '- (1,3-phenylene) N, N'-bis (3-aminophenyl) terephthalamide, N, N'- (4-aminophenyl) isophthalamide, N, N'-bis (3-aminophenyl) isophthalamide, 9,10- Bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2'-bis [4- , 2'-bis (4-aminophenyl) hexafluoropropane, 2,2'-bis (3-aminophenyl) hexafluoropropane, 2,2'- Aminophenyl) propane, 2,2'-bis (3-amino-4-methylphenyl) propane, 1,3-bis (4-aminophenoxy) propane, 1,4-bis (4-aminophenoxy) Bis (3-aminophenoxy) pentane, 1,5-bis (3-aminophenoxy) pentane, 6-bis (4-aminophenoxy) hexane, 1,6-bis (4-aminophenoxy) heptane, 1,8-bis (4-aminophenoxy) octane, 1,8-bis (3-aminophenoxy) octane, 1,9-bis (4-aminophenoxy) nonane, 1,9- 1,10- (3-aminophenoxy) undecane, 1,11- (4-aminophenoxy) undecane, 1,11- Octadecane, and 1,12- (3-aminophenoxy) dodecane; Alicyclic diamines such as bis (4-aminocyclohexyl) methane and bis (4-amino-3-methylcyclohexyl) methane; 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1, And aliphatic diamines such as 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, and 1,12-diaminododecane.

Examples of the diamine side chain include an alkyl group, a fluorine-containing alkyl group, an aromatic ring, an aliphatic ring, a heterocyclic ring, and diamines having a large-scission substituent formed therefrom. Specifically, diamines represented by the following formulas [A1] to [A20] can be exemplified.

[Chemical Formula 6]

(In the formulas [A1] to [A5], R ₁ represents an alkyl group having 1 to 22 carbon atoms or a fluorine-containing alkyl group)

(7)

(Wherein R ₂ represents COO, OCO, CONH, NHCO, CH ₂ , O, CO or NH and R ₃ represents a hydrogen atom, an alkyl group having 1 to 22 carbon atoms or a fluorine- Alkyl group)

[Chemical Formula 8]

(Wherein R ₄ represents O, OCH ₂ , CH ₂ O, COOCH ₂ or CH ₂ OCO, and R ₅ represents an alkyl group, an alkoxy group, a fluorine-containing alkyl group having 1 to 22 carbon atoms Or a fluorine-containing alkoxy group)

[Chemical Formula 9]

(Wherein R ₆ represents COO, OCO, CONH, NHCO, COOCH ₂ , CH ₂ OCO, CH ₂ O, OCH ₂ or CH ₂ , and R ₇ represents a C 1 to C 22 An alkyl group, an alkoxy group, a fluorine-containing alkyl group or a fluorine-containing alkoxy group)

[Chemical formula 10]

(Wherein R ₈ represents COO, OCO, CONH, NHCO, COOCH ₂ , CH ₂ OCO, CH ₂ O, OCH ₂ , CH ₂ , O or NH and R ₉ represents fluorine A cyano group, a trifluoromethyl group, a nitro group, an azo group, a formyl group, an acetyl group, an acetoxy group, a hydroxyl group, or a carboxyl group)

(11)

Also, a diaminosiloxane represented by the following formula [A21] can be exemplified.

[Chemical Formula 12]

(In the formula [A21], m represents an integer of 1 to 10)

The above-mentioned diamine may be used alone or in combination of two or more thereof, depending on the properties such as liquid crystal aligning property, voltage holding property, and accumulated charge when the liquid crystal alignment film is used.

Use of a raw material having a hydroxyl group or a carboxyl group in the above-mentioned starting materials for synthesizing a polyamic acid can increase the reaction efficiency of the polyamic acid or the polyimide and the later-described crosslinkable compound. Specific examples of such raw materials include 2,5-diaminophenol, 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol , 3,3'-dihydroxy-4,4'-diaminobiphenyl, 3,3'-dicarboxy-4,4'-diaminobiphenyl, 3,5-diaminobenzoic acid, 2,5- Diaminobenzoic acid, diamines represented by the formulas [A22] to [A25], and the like.

[Chemical Formula 13]

(Formula [A22] ~ [A25] of, R ₁₀ represents a COO, OCO, CONH, NHCO, CH 2, O, CO, or NH)

[Chemical Formula 14]

(Wherein R ₁₁ represents COO, OCO, CONH, NHCO, COOCH ₂ , CH ₂ OCO, CH ₂ O, OCH ₂ , CH ₂ , O or NH, and R ₁₂ represents a hydroxyl group , Or a carboxyl group)

The organic solvent used for synthesizing the polyamic acid is not particularly limited as long as it dissolves the produced polyamic acid. Specific examples thereof include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, dimethylsulfoxide, tetramethylurea, pyridine, , Hexamethyl sulfoxide,? -Butyrolactone, isopropyl alcohol, methoxymethyl pentanol, dipentene, ethyl amyl ketone, methyl nonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, Ethyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol monobutyl ether, Glycol, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol-tert-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol mono Diethylene glycol dimethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene Glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl isobutyl ether, diisobutylene, An organic solvent such as methanol, ethanol, propanol, isopropanol, butanol, isopropanol, butanol, isobutanol, isobutanol, isobutanol, , Propylene carbonate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, Propylene glycol monomethyl ether, propylene glycol monoethyl ether, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3- Propyl propionate, butyl 3-methoxypropionate, diglyme, 4-hydroxy-4-methyl-2-heptanone, and the like. These may be used alone or in combination. Further, even a solvent in which the polyamic acid is not dissolved, it may be mixed with the above solvent in a range in which the produced polyamic acid is not precipitated. Furthermore, water in the organic solvent inhibits the polymerization reaction and causes hydrolysis of the produced polyamic acid. Therefore, it is preferable to use an organic solvent which is dehydrated and dried as much as possible.

As a method for reacting a tetracarboxylic acid and a derivative thereof in the synthesis of a polyamic acid and a diamine in an organic solvent, a method in which a solution in which a diamine is dispersed or dissolved in an organic solvent is stirred and the tetracarboxylic acid and its derivative A method of adding a tetracarboxylic acid or its derivative to a solution dispersed or dissolved in an organic solvent, or a method of adding a tetracarboxylic acid and its derivative and a diamine in an alternating manner And the like. These may be any method. When the tetracarboxylic acid and its derivative or diamine is composed of a plurality of compounds, they may be reacted in a preliminarily mixed state, or they may be reacted individually or sequentially, and the low molecular weight compounds reacted individually are mixed and reacted, .

The temperature at which the polyamic acid is synthesized can be selected arbitrarily from -20 deg. C to 150 deg. C, preferably from -5 deg. C to 100 deg. The reaction can be carried out at an arbitrary concentration. However, if the concentration is too low, it becomes difficult to obtain a polymer having a high molecular weight. If the concentration is too high, the viscosity of the reaction solution becomes excessively high and uniform stirring becomes difficult. To 50% by mass, and more preferably 5 to 30% by mass. The reaction may be carried out at a high concentration in the initial stage, and then an organic solvent may be added.

In the synthesis of the polyamic acid, the ratio of the number of moles of the diamine component to the moles of the tetracarboxylic acid and the derivative thereof is preferably 0.8 to 1.2, more preferably 0.9 to 1.1. As in the case of a typical polycondensation reaction, the closer the molar ratio is to 1.0, the larger the molecular weight of the resulting polyamic acid.

Examples of a method for imidizing polyamic acid include heat imidization by heating and catalyst imidization using a catalyst. However, the catalyst imidization in which the imidization reaction proceeds at a relatively low temperature, the molecular weight reduction of the obtained polyimide Is difficult to occur.

The catalyst imidization can be carried out by stirring the polyamic acid in an organic solvent in the presence of a basic catalyst and an acid anhydride. The reaction temperature in this case is -20 to 250 ° C, preferably 0 to 180 ° C. When the reaction temperature is high, the imidization proceeds quickly, but when the reaction temperature is too high, the molecular weight of the polyimide may be lowered. The amount of the basic catalyst is 0.5 to 30 moles, preferably 2 to 20 moles, of the amide group, and the amount of the acid anhydride is 1 to 50 moles, preferably 3 to 30 moles, of the amide group. When the amount of the basic catalyst or the acid anhydride is small, the reaction does not proceed sufficiently. If the amount is too large, it is difficult to completely remove the catalyst after the completion of the reaction.

Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine, etc. Among them, pyridine is preferred because it has a basicity suitable for proceeding the reaction. As the acid anhydride, acetic anhydride, trimellitic anhydride, pyromellitic anhydride and the like can be mentioned. Among them, acetic anhydride is preferable because purification is facilitated after completion of the reaction.

The organic solvent is not limited as long as it dissolves polyamic acid. Specific examples thereof include N, N'-dimethylformamide, N, N'-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, dimethylsulfoxide, tetramethylurea, dimethylsulfone , Hexamethyl sulfoxide, gamma -butyrolactone, and the like. The imidization rate by the catalyst imidization can be controlled by adjusting the catalyst amount, the reaction temperature, and the reaction time.

The resulting polyimide is obtained by introducing the reaction solution into a poor solvent and recovering the resulting precipitate. The poor solvent to be used is not particularly limited, and examples thereof include methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, have. The polyimide precipitated by charging into a poor solvent can be filtered and then converted into a powder at room temperature or under reduced pressure or by heating and drying. The polyimide may be purified by dissolving the polyimide powder again in an organic solvent and repeating the procedure of reprecipitation 2 to 10 times. When the impurities are not completely removed by one settling recovery operation, it is preferable to carry out this purification step.

The molecular weight of the specific polyimide used in the present invention is not particularly limited, but is preferably from 2,000 to 200,000, more preferably from 4,000 to 50,000, in terms of weight average molecular weight, from the viewpoints of ease of handling and stability of characteristics at the time of film formation . The molecular weight was determined by GPC (Gel Permeation Chromatography).

≪ Component (B): Specific crosslinking compound >

The liquid crystal alignment treatment agent of the present invention contains, in addition to the polymer component, a crosslinkable compound (hereinafter referred to as a specific crosslinkable compound) having at least two oxetane groups represented by the following formula [1] in the molecule.

[Chemical Formula 15]

The oxetane group is known to react with a carboxyl group or a hydroxyl group in the presence of heat or an acid catalyst. Therefore, a specific crosslinking compound reacts with a carboxyl group or a hydroxyl group contained in a polyamic acid or a polyimide, thereby becoming a crosslinked film between the polymers. Further, the oxetane group causes a self-polymerization reaction in addition to a reaction with a carboxyl group or a hydroxyl group. Particularly, because oxetane groups are more nucleophilic than epoxy groups, a polymer having a high final conversion ratio and a high degree of polymerization can be obtained. That is, the liquid crystal alignment film obtained by using the liquid crystal alignment treatment agent of the present invention is a film having high heat resistance due to the polymer produced by crosslinking between polymers and autocopolymerization of oxetane group.

Since the oxetane group has a four-atom cyclic structure, it contains one methylene group at a bonding site in comparison with an epoxy group having a three-atom cyclic structure at the time of reacting with a carboxyl group or a hydroxyl group and at the time of self-polymerization. Therefore, the film obtained from the liquid crystal alignment treatment agent of the present invention has a higher elongation and toughness as compared with a film using an epoxy-based crosslinkable compound, so that the stretching property of the polymer due to rubbing is hardly inhibited.

Therefore, the liquid crystal alignment film obtained from the liquid crystal alignment treatment agent of the present invention has improved stability against heat at the pretilt angle, as compared with a liquid crystal alignment film containing no crosslinkable compound or a liquid crystal alignment film containing an epoxy crosslinkable compound, The orientation of the liquid crystal is not deteriorated even under a weak rubbing condition.

In the liquid crystal alignment treatment agent of the present invention, the oxetane group contained in the specific crosslinkable compound is not particularly limited as long as it is two or more, but is preferably 2 to 50, more preferably 2 to 20.

The specific structure of the specific crosslinkable compound is not particularly limited, and for example, a compound represented by the following formula [2] can be exemplified.

[Chemical Formula 16]

In the formula [2], X ₁ represents an organic group of N, NH, CO, O, S, SO ₂ , Si, silsesquioxane, polysiloxane or a carbon number of 1 to 20, , S, Si) may be contained. The organic group having 1 to 20 carbon atoms represented by X ₁ may contain an organic group having a cyclic structure. Specific examples thereof include a cyclopropane ring, a cyclopentane ring, a cyclopentane ring, a cyclohexane ring, a cycloheptane ring, a cyclooctane ring, a cyclononane ring, a cyclodecane ring, a cyclododecane ring, a cyclododecane ring, , A cyclotetradecane ring, a cyclopentadecane ring, a cyclohexadecane ring, a cycloheptadecane ring, a cyclooctadecane ring, a cyclooctadecane ring, a cyclononadecane ring, a cyclooic acid ring, a tricycloicoic acid ring, a tricyclodecanoic acid ring, A heterocyclic ring, a phenanthrene ring, a phenanthrene ring, a benzene ring, a naphthalene ring, a tetrahydronaphthalene ring, an azulene ring, an indene ring, a fluorene ring, an anthracene ring, a phenanthrene ring, , Pyrrole ring, imidazole ring, oxazole ring, thiazole ring, pyrazole ring, pyridine ring, pyrimidine A pyrimidine ring, a pyrazoline ring, a pyrazoline ring, an isoquinoline ring, a carbazole ring, a purine ring, a thiadiazole ring, a pyridazine ring, a triazine ring, a pyrazolidine ring, A benzothiazole ring, a phenothiazine ring, an oxadiazole ring, an acridine ring, an oxazole ring, a piperazine ring, a pyrimidine ring, a pyrimidine ring, a pyrimidine ring, A pyridine ring, a dioxane ring, a morpholine ring, an azepine ring, a diazepine ring, a naphthyridine ring, a phenazine ring, a phthalazine ring, and the like. X ₂ and X ₃ each independently represent a single bond, NH, CO, O, S, SO ₂ or an organic group having 1 to 20 carbon atoms, and heteroatoms (N, O, S, Si) .

Y ₁ and Y ₂ each independently represent an organic group having 1 to 20 carbon atoms, preferably 1 to 15 carbon atoms, and hetero atoms (N, O, S, Si) may be contained in the organic group.

m and n each independently represent an integer of 0 to 20, preferably an integer of 0 to 15, and m + n represents an integer of 2 to 20, preferably an integer of 2 to 15.

In the specific crosslinkable compound represented by the formula [2], it is preferable that X ₁ represents N, NH, CO, O, silsesquioxane, polysiloxane or an organic group having 1 to 10 carbon atoms, N, O). The organic group of X ₁ having 1 to 10 carbon atoms may contain a cyclohexane ring, a benzene ring, a naphthalene ring, a fluorene ring, a pyrrole ring, an imidazole ring, a pyrazole ring, , An organic group having a cyclic structure of a pyrimidine ring, a carbazole ring, a pyridazine ring, a triazine ring, a triazole ring, a pyrazine ring, a benzimidazole ring, or a quinoxaline ring may be contained. Y ₁ and Y ₂ are each independently an alkyl group having 1 to 10 carbon atoms, and m and n are each independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and X ₂ and X ₃ are each independently NH, CO, COO, OCO, O, CONH or NHCO, Represents an integer of 0 to 20, and m + n is an integer of 2 to 20.

In the formula [2], when X ₁ is silsesquioxane, examples thereof include structures selected from the general formulas [S1] to [S4].

[Chemical Formula 17]

In the formula [2], when X ₂ is a polysiloxane, examples of the polysiloxane include at least one structure selected from the group consisting of the general formulas [P1], [P2], [P3], and [P4] ≪ / RTI >

[Chemical Formula 18]

R ₁ , R ₂ , R ₃ , R ₄ and R ₅ in formulas [P1] to [P4] each independently represent a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 10 carbon atoms, an alkoxy group, Group.

Specific preferred examples of the formula [2] include structures represented by the following formulas [3] to [8].

[Chemical Formula 19]

In the formula [3], X ₂ and X ₃ each independently represent a single bond, NH, CO, O, S, SO ₂ or an organic group having 1 to 20 carbon atoms, S, and Si), Y ₁ and Y ₂ each independently represent an organic group having 1 to 20 carbon atoms, preferably 1 to 15 carbon atoms, and heteroatoms (N, O, S, Si ) May be contained. Z ₁ is a single _{bond, NH, N (CH 3)} , NHCO, CONH, NHCONH, CO, COO, O, S, SO 2, CF 2, C (CF 3) 2, Si (CH 3) 2, OSi ( (CH ₃ ) ₂ , Si (CH ₃ ) ₂ O, OSi (CH ₃ ) ₂ O, or an alkyl group having 1 to 10 carbon atoms. m and n each independently represent an integer of 0 to 5, preferably 0 to 3, and m + n represents an integer of 2 to 10, preferably an integer of 2 to 6.

In certain crosslinking compound represented by the formula [3], preferably, X ₂ and R X ₃ are each independently NH, CO, COO, OCO, O, CONH, or NHCO, Z ₁ is a single bond, CH _{2, C (CH 3) 2, NH} , N (CH 3), NHCO, CONH, CO, COO, O, SO 2, C (CF 3) 2, Si (CH 3) 2, OSi (CH 3) 2, Si (CH ₃ ) ₂ O, OSi (CH ₃ ) ₂ O, or an alkyl group having 1 to 5 carbon atoms, Y ₁ and Y ₂ are each independently an alkyl group having 1 to 10 carbon atoms, m and n, Preferably an integer of 0 to 3, and m + n is an integer of 2 to 10, preferably an integer of 2 to 6.

[Chemical Formula 20]

In the formula [4], X ₁ is _{NH, N (CH 3),} NHCO, CONH, NHCONH, CO, COO, OCO, O, S, SO 2, CF 2, C (CF 3) 2, Si (CH 3 ) ₂ , OSi (CH ₃ ) ₂ , Si (CH ₃ ) ₂ O, or OSi (CH ₃ ) ₂ O, Y ₁ and Y ₂ each independently represent an alkyl group having 1 to 10 carbon atoms, ≪ / RTI >

In certain crosslinking compound represented by the formula [4], preferably, X ₁ is NH, N (CH _3), NHCO, CONH, CO, COO, OCO, O, SO _2, C (CF _{3) 2,} Si _{(CH 3) 2, OSi (} CH 3) 2, Si (CH 3) 2 O, or an OSi _{(CH 3) 2 O, Y} 1 and Y ₂ is an alkyl group having 1 to 10 carbon atoms independently.

[Chemical Formula 21]

X ₁ in the formula [5] represents N, an aliphatic ring having 1 to 20 carbon atoms, an aromatic ring having 1 to 20 carbon atoms or an alkylene having 1 to 20 carbon atoms, preferably N, an aliphatic ring having 1 to 15 carbon atoms, An aromatic ring of 1 to 15 carbon atoms or an alkylene of 1 to 15 carbon atoms. More preferably, X ₁ is N, an aliphatic ring having 1 to 10 carbon atoms, an aromatic ring having 1 to 10 carbon atoms, or an alkylene having 1 to 10 carbon atoms.

Y ₁ and Y ₂ in the formula [5] each represent an alkyl group having 1 to 10 carbon atoms, preferably an alkyl group having 1 to 5 carbon atoms.

M and n in the formula [5] represent an integer of 0 to 20, and m + n is an integer of 2 to 20. Preferably, m and n are integers of 0 to 15, and m + n is an integer of 2 to 15. More preferably, m and n each represent an integer of 0 to 10, and m + n is an integer of 2 to 10.

Thus, preferable combinations of X ₁ , Y ₁ , Y ₂ , m and n are as follows.

Wherein X ₁ in Formula [5] is N, an aliphatic ring having 1 to 20 carbon atoms, an aromatic ring having 1 to 20 carbon atoms, or an alkylene having 1 to 20 carbon atoms, Y ₁ and Y ₂ are each an alkyl group having 1 to 10 carbon atoms, m and n are integers of 0 to 20, and m + n is an integer of 2 to 20.

Preferably, X ₁ is N, an aliphatic ring having 1 to 15 carbon atoms, an aromatic ring having 1 to 15 carbon atoms or an alkylene having 1 to 15 carbon atoms, Y ₁ and Y ₂ are each an alkyl group having 1 to 5 carbon atoms, m, n is an integer of 0 to 15, and m + n is an integer of 2 to 15.

More preferably, X ₁ is N, an aliphatic ring having 1 to 10 carbon atoms, an aromatic ring having 1 to 10 carbon atoms or an alkylene having 1 to 10 carbon atoms, Y ₁ and Y ₂ are each an alkyl group having 1 to 5 carbon atoms, m , n is an integer of 0 to 10, and m + n is an integer of 2 to 10.

Specific examples of the aliphatic ring having 1 to 20 carbon atoms and the aromatic ring having 1 to 20 carbon atoms in X ₁ are shown below.

Examples of the aliphatic ring include cyclopropane ring, cyclobutane ring, cyclopentane ring, cyclohexane ring, cycloheptane ring, cyclooctane ring, cyclononane ring, cyclodecane ring, cyclododecane ring, cyclododecane ring, And examples thereof include a ring, a cyclotetradecane ring, a cyclopentadecane ring, a cyclohexadecane ring, a cycloheptadecane ring, a cyclooctadecane ring, a cyclononadecane ring, a cyclooic acid ring, a tricycloicoic acid ring, a tricyclodecanoic acid ring, A cycloheptane ring, a norbornene ring, and an adamantane ring.

Examples of the aromatic ring include an aromatic ring such as a decahydronaphthalene ring, a benzene ring, a naphthalene ring, a tetrahydronaphthalene ring, an azulene ring, an indene ring, a fluorene ring, an anthracene ring, a phenanthrene ring, a phenalene ring, A pyrimidine ring, a pyrimidine ring, a pyrazoline ring, an isoquinoline ring, a carbazole ring, a purine ring, a thiadiazole ring, a pyridazine ring, a triazine ring, a thiadiazole ring, A pyrazolidine ring, a triazole ring, a pyrazine ring, a benzimidazole ring, a benzimidazole ring, a chinoline ring, a phenanthroline ring, an indole ring, a quinoxaline ring, a benzothiazole ring, a phenothiazine ring, A heterocyclic ring, a heterocyclic ring, an azepine ring, a diazepine ring, a naphthyridine ring, a phenanthrene ring, an acridine ring, an oxazole ring, a piperazine ring, a piperidine ring, There may be mentioned a ring, phthalazine ring.

Among them, preferable examples include a cyclopentane ring, a cyclohexane ring, a norbornene ring, an adamantane ring, a benzene ring, a naphthalene ring, a tetrahydronaphthalene ring, a fluorene ring, an anthracene ring, a pyrrole ring, A pyrimidine ring, a pyrimidine ring, a pyrazoline ring, a carbazole ring, a pyridazine ring, a triazine ring, a triazole ring, a pyrazine ring, a benzimidazole ring, a piperazine ring, A pyridine ring and a piperidine ring. More preferably a cyclohexane ring, a norbornene ring, an adamantane ring, a benzene ring, a naphthalene ring, a tetrahydronaphthalene ring, a pyrrole ring, an imidazole ring, a pyridine ring, a pyrimidine ring, a carbazole ring, , Triazine ring, triazole ring, pyrazine ring, benzimidazole ring, piperazine ring, and piperidine ring.

[Chemical Formula 22]

In formula [6], Y ₁ and Y ₂ each independently represent an alkyl group having 1 to 10 carbon atoms, preferably an alkyl group having 1 to 5 carbon atoms, and n is an integer of 1 to 10, preferably an integer of 1 to 5 .

(23)

In formula [7], Y ₁ and Y ₂ each independently represent an alkyl group having 1 to 10 carbon atoms, preferably an alkyl group having 1 to 5 carbon atoms, and n is an integer of 1 to 10, preferably an integer of 1 to 5 .

≪ EMI ID =

In formula [8], Y ₁ and Y ₂ each independently represent an alkyl group having 1 to 10 carbon atoms, preferably an alkyl group having 1 to 5 carbon atoms, and n is an integer of 1 to 10, preferably an integer of 1 to 5 .

Specific examples of the specific crosslinking compound include the compounds of the formulas [9] to [19].

(25)

(26)

(27)

The compound is not limited to the specific examples of the specific crosslinking compound. The specific crosslinkable compound contained in the liquid crystal alignment treatment agent of the present invention may be a single type or a combination of two or more types.

(Liquid crystal alignment treatment agent)

The content of the component (B) (the specific crosslinkable compound) in the liquid crystal alignment treatment agent of the present invention is preferably from 0.1 to 150 parts by mass per 100 parts by mass of the component (A) (polymer component) comprising a polyamic acid and / More preferably from 0.1 to 100 parts by mass, and particularly preferably from 1 to 50 parts by mass, in order that the crosslinking reaction proceeds to exhibit desired film curability and does not lower the alignment property of the liquid crystal.

The liquid crystal alignment treatment agent of the present invention is not particularly limited, but it is usually necessary to form a homogeneous thin film of 0.01 to 1.0 탆 on the substrate at the time of producing the liquid crystal alignment film. Therefore, the component (A) Is preferably a coating liquid containing an organic solvent for dissolving these components. When the liquid crystal alignment treating agent of the present invention contains the organic solvent, the content of the organic solvent is preferably 90 to 99% by mass, more preferably 92 to 99% by mass, and more preferably 90 to 99% by mass, from the viewpoint of forming a uniform thin film by coating. By mass to 97% by mass. On the other hand, the content of the component (A) is preferably 0.4 to 9.9 mass%, particularly preferably 0.5 to 9.9 mass%, the content of the component (B) is preferably 0.1 to 9.6 mass% Is 0.1 to 9.5 mass%. These contents can be appropriately changed depending on the film thickness of the intended liquid crystal alignment film.

Specific examples of the organic solvent to be contained in the liquid crystal alignment treatment agent of the present invention include organic solvents used in the synthesis reaction of the aforementioned polyamic acid. Particularly preferred are N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, dimethylsulfoxide and gamma -butyrolactone. These organic solvents may be used alone or in combination of two or more.

In the organic solvent, for the purpose of improving the uniformity of the coating film, ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, diethylene glycol diethyl ether, diethylene glycol monoethyl ether, diethylene Methoxy-2-propanol, 1-ethoxy-2-propanol, 1-butoxy-2-propanol, 1-phenoxy Propanol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether-2-acetate, dipropylene glycol, dipropylene glycol monomethyl Propanol, lactic acid methyl ester, lactic acid ethyl ester, n-propyl lactate (1-ethylhexyl) Le, et acid n- butyl ester, lactic acid isoamyl ester, preferably contains a solvent having a low surface tension. These solvents are usually used alone or in combination of two or more. These solvents generally have a low ability to dissolve the polyamic acid or the polyimide, and therefore are preferably 80 mass% or less, and more preferably 60 mass% or less, in the organic solvent. If it is expected that the uniformity of the coating film is improved, it is preferably 5% by mass or more, more preferably 20% by mass or more, in the organic solvent.

The liquid crystal alignment treatment agent of the present invention may contain an additive component in addition to the component (A), the component (B), and the organic solvent as long as the effect of the present invention is not impaired. Examples of the additive component include a compound for improving the adhesion between the liquid crystal alignment film and the substrate, and a surfactant for improving the planarization property of the coating film.

Specific examples of the compound that improves the adhesion between the coating film and the substrate include those shown below. For example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl) -3 3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxy (2-aminoethyl) Aminopropyltriethoxysilane, N-trimethoxysilylpropyltriethoxysilane, N-trimethoxysilylpropyltriethoxysilane, N-trimethoxysilylpropyltriethoxysilane, N-trimethoxysilylpropyltriethoxysilane, Amine, 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- Bis (oxyethylene) -3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N- Aminopropyltriethoxysilane, and the like.

When these compounds are added, the amount is preferably from 0.1 to 30 parts by mass, more preferably from 1 to 30 parts by mass, per 100 parts by mass of the component (A) from the viewpoint of obtaining an effect of improving the adhesiveness and not lowering the orientation property of the liquid crystal. Particularly preferably 1 to 10 parts by mass.

Examples of the surfactant for improving the planarizing property of the coating film include a fluorine surfactant, a silicone surfactant, and a nonionic surfactant. More specifically, for example, EF301, EF303 and EF352 (manufactured by TOKEM PRODUCTS CO., LTD.), Megafac F171, F173 and R-30 (manufactured by Dainippon Ink and Chemicals Inc.), FLORAD FC430 and FC431 SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by Asahi Glass Co., Ltd.)), and the like. The proportion of these surfactants to be used is preferably 0.01 to 2 parts by mass, more preferably 0.01 to 1 part by mass based on 100 parts by mass of the polymer component.

<Liquid Crystal Alignment Film / Liquid Crystal Display Device>

The liquid crystal alignment treatment agent of the present invention can be used as a liquid crystal alignment film without rubbing treatment, light irradiation or the like, or without alignment treatment in a vertical alignment application, after coating and baking on a substrate.

At this time, the substrate to be used is not particularly limited as long as it is a substrate having high transparency. A plastic substrate such as an acrylic substrate or a polycarbonate substrate; Etc. may be used. It is also preferable to use a substrate on which an ITO electrode or the like for liquid crystal driving is formed from the viewpoint of simplifying the process. In a reflection type liquid crystal display element, an opaque substrate such as a silicon wafer may be used if only one side of the substrate is used. In this case, a material that reflects light such as aluminum can also be used as the electrode in this case.

The method of applying the liquid crystal alignment treatment agent is not particularly limited, but industrially, methods such as screen printing, offset printing, flexographic printing, and inkjet are generally used. As other coating methods, there are dip, roll coater, slit coater, spinner and the like, and they may be used depending on the purpose.

The baking after applying the liquid crystal alignment treatment agent can be carried out at any temperature of 100 to 350 ° C, preferably 120 to 300 ° C, and more preferably 150 to 250 ° C. This firing can be carried out in a hot plate, a hot air circulation furnace, an infrared furnace or the like.

The thickness of the coated film after firing is disadvantageous from the viewpoint of power consumption of the liquid crystal display element if it is excessively large and from 5 to 300 nm, 100 nm. When the liquid crystal is horizontally oriented or tilted, the film after baking is treated by rubbing, polarized ultraviolet irradiation, or the like.

In the liquid crystal display element of the present invention, a substrate on which a liquid crystal alignment film is formed from the liquid crystal alignment treatment agent of the present invention is obtained by the above-mentioned technique, and then a liquid crystal cell is produced by a known method to form a liquid crystal display element.

For example, a pair of substrates on which a liquid crystal alignment film is formed is prepared. Spacers are dispersed on the liquid crystal alignment film of the substrate of the single chamber to make the liquid crystal alignment film face inward, and another substrate is attached A method of sealing the liquid crystal by injection at a reduced pressure or a method of dropping a liquid crystal on the liquid crystal alignment film surface on which the spacer is dispersed and then sealing the substrate by attaching the substrate. The thickness of the spacer at this time is preferably 1 to 30 占 퐉, more preferably 2 to 10 占 퐉.

Thus, the liquid crystal display device manufactured using the liquid crystal alignment treatment agent of the present invention can be used as a liquid crystal display device having excellent stability of the pretilt angle, and can be used as a TN device, an STN device, a TFT liquid crystal device, Liquid crystal display elements and the like.

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

The abbreviations of the compounds used in this embodiment are as follows.

(Tetracarboxylic dianhydride)

CBDA: 1,2,3,4-Cyclobutane tetracarboxylic acid dianhydride

BODA: bicyclo [3,3,0] octane-2,4,6,8-tetracarboxylic acid dianhydride

(28)

(Diamine)

p-PDA: p-phenylenediamine

DBA: 3,5-diaminobenzoic acid

DADPA: 4,4'-diaminodiphenylamine

AP18: 4- (octadecyloxy) -1,3-phenylenediamine

PCH: 1,3-diamino-4- [4- (4-heptylcyclohexyl) phenoxy] benzene

[Chemical Formula 29]

(Oxetane-based crosslinking compound)

Oxetane (A): OXT-221 (manufactured by Toagosei Co., Ltd.)

Oxetane (B): OX-SQ-H (manufactured by Toagosei Co., Ltd.)

Oxetane (C): 0X-SC (manufactured by Toagosei Co., Ltd.)

(30)

(Epoxy-based crosslinking compound)

Epoxy A: YH-434L (manufactured by Toto Chemical Industry Co., Ltd.)

Epoxy B: EPOLED GT-401 (tetrafunctional alicyclic epoxy resin) (manufactured by Daicel Chemical Industries, Ltd.); Epoxidized butanetetracarboxylic acid tetrakis- (3-cyclohexenylmethyl) -methylcaprolactone

(31)

(Organic solvent)

NMP: N-methyl-2-pyrrolidone

BCS: butyl cellosolve

&Lt; Measurement of molecular weight of polyimide &

The molecular weight of the polyimide in Synthesis Example was measured using a room temperature gel permeation chromatography (GPC) apparatus (SSC-7200) manufactured by Senshu Scientific Co., Ltd., a column (KD-803, KD-805) Respectively.

Column temperature: 50 ° C

Eluent: 30 mmol / l of lithium bromide-hydrate (LiBr.H ₂ O), 30 mmol / l of phosphoric acid-anhydrous crystal (o-phosphoric acid), 30 ml of tetrahydrofuran THF) of 10 ml / l)

Flow rate: 1.0 ml / min

Standard sample for preparing a calibration curve: TSK standard polyethylene oxide (molecular weight about 900,000, 150,000, 100,000, 30,000) manufactured by Tosoh Corporation and polyethyleneglycol (molecular weight about 12,000, 4,000, 1,000) manufactured by Polymer Laboratories.

&Lt; Measurement of imidization rate &

The imidization rate of the polyimide in the synthesis example was measured as follows. 20 mg of polyimide powder was placed in an NMR sample tube (NMR sampling tube standard φ5 mm manufactured by Kusano Scientific Co., Ltd.), 0.53 ml of deuterated dimethyl sulfoxide (DMSO-d ₆ , 0.05% TMS mixture) was added, . The solution in the tube was measured for proton NMR at 500 MHz with a Nippon Electronics Daytome NMR analyzer (JNW-ECA500). The imidization rate is determined by using a proton derived from a structure that is not changed before and after imidization as a reference proton, and the peak integrated value of the proton and the proton peak integration derived from the NH group of the amic acid appearing in the vicinity of 9.5 to 10.0 ppm Value was obtained by the following equation.

Imidization ratio (%) = (1 -? X / y) x 100

X is the proton peak integrated value derived from the NH group of the amic acid, y is the peak integrated value of the reference proton, and? Is the NH group proton 1 of the amic acid when the polyamic acid (imidization ratio is 0%) Is the ratio of the number of reference protons to the number of protons.

(Synthesis Example 1)

(5.1 g, 26.0 mmol), p-PDA (2.53 g, 23.4 mmol) and AP18 (0.98 g, 2.6 mmol) were mixed in 81.5 g of NMP and reacted at 25 ° C for 6 hours to obtain polyamic acid To obtain a solution (A). This polyamic acid solution (A) had a number average molecular weight of 22,000 and a weight average molecular weight of 78,900.

(Synthesis Example 2)

The mixture of CBDA (3.04 g, 15.5 mmol), p-PDA (1.56 g, 14.4 mmol) and PCH (0.61 g, 1.6 mmol) were mixed in NMP (22.0 g) and reacted at 25 ° C for 5 hours, To obtain a solution (B). This polyamic acid solution (B) had a number average molecular weight of 25,000 and a weight average molecular weight of 94,000.

(Synthesis Example 3)

BODA (16.9 g, 68 mmol), p-PDA (8.74 g, 81 mmol) and PCH (3.43 g, 9 mmol) were mixed in NMP (100.1 g) and reacted at 40 ° C for 3 hours. , 21 mmol) and NMP (52.2 g) were added and reacted at 40 占 폚 for 3 hours to obtain a polyamic acid solution (C). This polyamic acid (C) had a number average molecular weight of 20500 and a weight average molecular weight of 76,500.

(Synthesis Example 4)

BODA (150.1 g, 600 mmol), DBA (60.9 g, 400 mmol) and PCH (152.2 g, 400 mmol) were mixed in NMP (1290 g) and reacted at 80 ° C for 5 hours. ) And NMP (320 g) were added and reacted at 40 ° C for 3 hours to obtain a polyamic acid solution (D). This polyamic acid (D) had a number average molecular weight of 24,400 and a weight average molecular weight of 98,500.

(Synthesis Example 5)

NMP was added to the polyamic acid solution (C) (130.3 g) obtained in Synthesis Example 3 to dilute it to 6 mass%, acetic anhydride (15.6 g) and pyridine (12.1 g) were added as an imidation catalyst, And reacted for 3 hours. This reaction solution was poured into methanol (1600 ml), and the resulting precipitate was separated by filtration. The precipitate was washed with methanol, and dried at 100 ° C under reduced pressure to obtain a polyimide powder (E). The imidization ratio of the polyimide was 54%, the number average molecular weight was 18,300, and the weight average molecular weight was 45,300.

(Synthesis Example 6)

NMP was added to the polyamic acid solution (D) (600.2 g) obtained in Synthesis Example 4 to dilute it to 6 mass%, acetic anhydride (63.9 g) and pyridine (49.6 g) were added as an imidation catalyst, And reacted for 3 hours. The reaction solution was poured into methanol (7700 ml), and the obtained precipitate was separated by filtration. The precipitate was washed with methanol, and dried at 100 ° C under reduced pressure to obtain a polyimide powder (F). The imidization ratio of the polyimide was 57%, the number average molecular weight was 23,000, and the weight average molecular weight was 80,200.

(Synthesis Example 7)

NMP was added to the polyamic acid solution (D) (101.2 g) obtained in Synthesis Example 4 to dilute it to 6 mass%, then acetic anhydride (21.3 g) and pyridine (16.5 g) And reacted for 3 hours. This reaction solution was poured into methanol (1300 ml), and the resulting precipitate was separated by filtration. The precipitate was washed with methanol, and dried at 100 ° C under reduced pressure to obtain a polyimide powder (G). The imide ratio of the polyimide was 81%, the number average molecular weight was 20400, and the weight average molecular weight was 63000.

(Example 1)

Oxetane (A) (0.11 g), NMP (4.76 g) and BCS (2.53 g) were added to the polyamic acid solution (A) (6.00 g) obtained in Synthesis Example 1 and stirred to prepare a liquid crystal alignment treatment agent [ .

The liquid crystal alignment treatment agent [1] obtained above was spin-coated on the ITO surface of a substrate with a 3 cm x 4 cm ITO electrode and subjected to a heat treatment at 80 캜 for 5 minutes and at 230 캜 for 30 minutes to obtain a polyimide coating film &Lt; / RTI &gt; The coated surface was rubbed under the conditions of a roll diameter of 120 mm, a rubbing device of a Ray-Onsen, a rotation speed of 700 rpm, a moving speed of 40 mm / sec, and an indentation amount of 0.3 mm to obtain a substrate on which a liquid crystal alignment film was formed. Two substrates each having the liquid crystal alignment film formed thereon were prepared, and the liquid crystal alignment film surface was set in the inner side so that spacers of 50 mu m were interposed therebetween, and the rubbing directions were reversed. Liquid crystal ZLI-2293 (manufactured by Merck Japan Co., Ltd.) was injected into this empty cell by a vacuum injection method, and the injection port was sealed to obtain a nematic liquid crystal cell of anti-parallel alignment.

The pretilt angle (degrees) of the liquid crystal cell after the liquid crystal injection and at the initial stage of heat treatment at 120 DEG C for 5 hours was measured at room temperature using a pretilometer (ELSICON PAS-301) . Initial and after each heat treatment, the alignment uniformity of the liquid crystal was confirmed by observation of a polarizing microscope with respect to the liquid crystal cell. As a result, none of the liquid crystal cells had orientation defects and the liquid crystal was uniformly oriented.

The retardation angle of the liquid crystal cell prepared in the same manner as above was measured at the initial stage after the liquid crystal injection and after the heat treatment at 120 ° C for 5 hours, except that the amount of the rubbing treatment was adjusted to 0.1 mm. When the alignment uniformity of the liquid crystal was confirmed by observing a polarizing microscope with respect to these liquid crystal cells, none of the liquid crystal cells exhibited orientation defects, and the liquid crystal was uniformly oriented.

The measurement results of the pretilt angle are shown in Table 1.

(Example 2)

Oxetane (A) (0.06 g), NMP (4.05 g) and BCS (2.35 g) were added to the polyamic acid solution (A) (6.05 g) obtained in Synthesis Example 1 and stirred to prepare a liquid crystal alignment treatment agent [ .

Using the obtained liquid crystal alignment treatment agent [2], a liquid crystal cell was produced in the same manner as in Example 1, and the initial tilt angle after the liquid crystal injection at 0.3 mm in the rubbing treatment and the heat treatment at 120 ° C for 5 hours Respectively. When the alignment uniformity of the liquid crystal was confirmed by observing a polarizing microscope with respect to the liquid crystal cell at the initial stage and after each heat treatment, none of the liquid crystal cells had orientation defects and the liquid crystal was uniformly oriented.

The pretilt angle was measured at the initial stage after the injection of the liquid crystal and after the heat treatment at 120 ° C for 5 hours for the liquid crystal cell produced in the same manner as above except that the indentation amount was set to 0.1 mm. For these liquid crystal cells, alignment homogeneity of the liquid crystal was confirmed by observation with a polarizing microscope. As a result, none of the liquid crystal cells had orientation defects and the liquid crystal was uniformly oriented.

The measurement results of the pretilt angle are shown in Table 1.

(Example 3)

Oxocane (B) (0.03 g), NMP (3.61 g) and BCS (2.21 g) were added to the polyamic acid solution (A) (6.00 g) obtained in Synthesis Example 1 and stirred to prepare a liquid crystal alignment treatment agent [ .

Using the obtained liquid crystal alignment treatment agent [3], a liquid crystal cell was produced in the same manner as in Example 1, and the initial post-liquid crystal injection at 0.3 mm in rubbing treatment and the posttilt angle after heat treatment at 120 캜 for 5 hours Respectively. When the alignment uniformity of the liquid crystal was confirmed by observing a polarizing microscope with respect to the liquid crystal cell after the initial and each heat treatment, no alignment defect was found in any of the liquid crystal cells, and the liquid crystal was uniformly oriented.

The pretilt angle was measured at the initial stage after the injection of the liquid crystal and after the heat treatment at 120 ° C for 5 hours for the liquid crystal cell produced in the same manner as above except that the indentation amount was set to 0.1 mm. For these liquid crystal cells, alignment homogeneity of the liquid crystal was confirmed by observation with a polarizing microscope. As a result, none of the liquid crystal cells had orientation defects and the liquid crystal was uniformly oriented.

The measurement results of the pretilt angle are shown in Table 1.

(Example 4)

Oxetane (A) (0.12 g), NMP (3.61 g) and BCS (2.4 g) were added to the polyamic acid solution (B) (6.00 g) obtained in Synthesis Example 2 and stirred to prepare a liquid crystal alignment treatment agent [ .

Using the obtained liquid crystal alignment treatment agent [4], a liquid crystal cell was produced in the same manner as in Example 1, and after the liquid crystal injection at an indentation amount of 0.3 mm for the rubbing treatment and for 5 hours at 120 ° C, Were measured. When the alignment uniformity of the liquid crystal was confirmed by observing a polarizing microscope with respect to the liquid crystal cell after the initial and each heat treatment, no alignment defect was found in any of the liquid crystal cells, and the liquid crystal was uniformly oriented.

The measurement results of the pretilt angle are shown in Table 1.

(Example 5)

(B) (0.03 g), NMP (2.41 g) and BCS (2.10 g) were added to the polyamic acid solution (B) (6.02 g) obtained in Synthesis Example 2 and stirred to prepare a liquid crystal alignment treatment agent [ .

A liquid crystal cell was prepared in the same manner as in Example 1 using the obtained liquid crystal alignment treatment agent [5]. The liquid crystal cell was subjected to heat treatment at 120 캜 for 5 hours after injection of the liquid crystal at a press- Respectively. When the alignment uniformity of the liquid crystal was confirmed by observing a polarizing microscope with respect to the liquid crystal cell after the initial and each heat treatment, no alignment defect was found in any of the liquid crystal cells, and the liquid crystal was uniformly oriented.

The measurement results of the pretilt angle are shown in Table 1.

(Comparative Example 1)

NMP (3.06 g) and BCS (2.12 g) were added to the polyamic acid solution (A) (6.00 g) obtained in Synthesis Example 1 and stirred to obtain a liquid crystal alignment treatment agent [6].

Using the obtained liquid crystal alignment treatment agent [6], a liquid crystal cell was produced in the same manner as in Example 1. The initial post-liquid crystal injection at 0.3 mm in the rubbing treatment and the posttilt angle after heat treatment at 120 캜 for 5 hours Respectively. When the alignment uniformity of the liquid crystal was confirmed by observing a polarizing microscope with respect to the liquid crystal cell after the initial and each heat treatment, no alignment defect was found in any of the liquid crystal cells, and the liquid crystal was uniformly oriented.

The measurement results of the pretilt angle are shown in Table 1.

(Comparative Example 2)

NMP (2.01 g) and BCS (1.99 g) were added to the polyamic acid solution (B) (6.01 g) obtained in Synthesis Example 2 and stirred to obtain a liquid crystal alignment treatment agent [7].

Using the obtained liquid crystal alignment treatment agent [7], a liquid crystal cell was prepared in the same manner as in Example 1, and the pretilt angle was measured after heating treatment at 120 ° C for 5 hours at the initial stage after injecting the liquid crystal at a press- Respectively. When the alignment uniformity of the liquid crystal was confirmed by observing a polarizing microscope with respect to the liquid crystal cell at the initial stage and after each heat treatment, none of the liquid crystal cells had orientation defects and the liquid crystal was uniformly oriented.

The measurement results of the pretilt angle are shown in Table 1.

(Comparative Example 3)

Epoxy (A) (0.11 g), NMP (4.75 g) and BCS (2.52 g) were added to the polyamic acid solution (A) (6.00 g) obtained in Synthesis Example 1 and stirred to obtain a liquid crystal alignment treating agent [8] .

A liquid crystal cell was prepared in the same manner as in Example 1 using the obtained liquid crystal alignment treatment agent [8]. The liquid crystal cell was subjected to heat treatment at 120 캜 for 5 hours after injection of the liquid crystal at a press- Respectively. In the initial state of the liquid crystal cell, a so-called flow orientation in which the liquid crystal was aligned in the direction in which the liquid crystal flowed during liquid crystal injection was observed. In addition, at this stage after the heat treatment, this flow orientation was not solved, and a disclination line was generated by the heat treatment. Since such orientation defects have occurred, the pretilt angle of the liquid crystal cell can not be measured.

In addition, except that the indentation amount was set to 0.1 mm, the pretilt angle after the liquid crystal injection of the liquid crystal cell prepared as described above and the heat treatment at 120 ° C for 5 hours were measured, and the orientation of flow was observed in the initial state . After the heat treatment, the flow orientation was not solved, and a disclination line was generated. Therefore, the pretilt angle could not be measured.

The measurement results of the pretilt angle are shown in Table 1.

(Comparative Example 4)

Epoxy (A) (0.06 g), NMP (4.03 g) and BCS (2.34 g) were added to the polyamic acid solution (A) (6.05 g) obtained in Synthesis Example 1 and stirred to obtain a liquid crystal alignment treatment agent [9] .

A liquid crystal cell was prepared in the same manner as in Example 1 using the obtained liquid crystal alignment treatment agent [9], and a pretilt angle was measured after heating treatment at 120 ° C for 5 hours at the initial stage after injecting the liquid crystal at a press- Respectively. The alignment uniformity of the liquid crystal was confirmed by observation of a polarizing microscope with respect to the initial liquid crystal cell. As a result, alignment defect was not observed and the liquid crystal was uniformly oriented, but a disclination line was generated after heating at 120 deg. C for 5 hours. Therefore, it was impossible to measure the pretilt angle of the liquid crystal cell after heating at 120 ° C for 5 hours.

In addition, except that the indentation amount was set to 0.1 mm, the pretilt angle after the liquid crystal injection of the liquid crystal cell prepared as described above and the heat treatment at 120 ° C for 5 hours were measured, and the orientation of flow was observed in the initial state . After the heat treatment, the flow orientation was not solved, and a disclination line was generated. Therefore, the pretilt angle could not be measured.

The measurement results of the pretilt angle are shown in Table 1.

(Comparative Example 5)

Epoxy (B) (0.06 g), NMP (4.02 g) and BCS (2.35 g) were added to the polyamic acid solution (A) (6.00 g) obtained in Synthesis Example 1 and stirred to obtain a liquid crystal alignment treating agent [10] .

Using the obtained liquid crystal alignment treatment agent [10], a liquid crystal cell was prepared in the same manner as in Example 1, and the pretilt angle was measured after heating treatment at 120 ° C for 5 hours at the initial stage after injection of liquid crystal at a press- Respectively. The alignment uniformity of the liquid crystal was confirmed by observation of a polarizing microscope with respect to the initial liquid crystal cell. As a result, alignment defect was not observed and the liquid crystal was uniformly oriented, but a disclination line was generated after heating at 120 deg. C for 5 hours. Therefore, it was impossible to measure the pretilt angle of the liquid crystal cell after heating at 120 ° C for 5 hours.

In addition, except that the indentation amount was set to 0.1 mm, the pretilt angle after the liquid crystal injection of the liquid crystal cell prepared as described above and the heat treatment at 120 ° C for 5 hours were measured, and the orientation of flow was observed in the initial state . After the heat treatment, the flow orientation was not solved, and a disclination line was generated. Therefore, the pretilt angle could not be measured.

The measurement results of the pretilt angle are shown in Table 1.

(Example 6)

NMP (17.1 g) was added to the polyimide powder (E) (2.91 g) obtained in Synthesis Example 5 and dissolved by stirring at 80 占 폚 for 40 hours. To this solution, oxetane (A) (0.60 g), NMP (12.2 g) and BCS (25.7 g) were added and stirred to obtain a liquid crystal alignment treatment agent [11].

A liquid crystal cell was prepared in the same manner as in Example 1 except that the obtained liquid crystal alignment treatment agent [11] was used to make a liquid crystal MLC-6608 (manufactured by Merck Japan Co.). Subsequently, the post tilt angle was measured after the liquid crystal injection at an indentation amount of 0.3 mm for the rubbing treatment and after the heat treatment at 120 캜 for 5 hours. When the alignment uniformity of the liquid crystal was confirmed by observing a polarizing microscope with respect to the liquid crystal cell after the initial and each heat treatment, no alignment defect was found in any of the liquid crystal cells, and the liquid crystal was uniformly oriented.

The pretilt angle was measured at the initial stage after the injection of the liquid crystal and after the heat treatment at 120 ° C for 5 hours for the liquid crystal cell produced in the same manner as above except that the indentation amount was set to 0.1 mm. For these liquid crystal cells, alignment homogeneity of the liquid crystal was confirmed by observation with a polarizing microscope. As a result, none of the liquid crystal cells had orientation defects and the liquid crystal was uniformly oriented.

(Example 7)

NMP (18.0 g) was added to the polyimide powder (E) (3.05 g) obtained in Synthesis Example 5 and dissolved by stirring at 80 占 폚 for 40 hours. To this solution, oxetane (A) (0.31 g), NMP (6.65 g) and BCS (28.0 g) were added and stirred to obtain a liquid crystal alignment treatment agent [12].

A liquid crystal cell was prepared in the same manner as in Example 1 except that the obtained liquid crystal alignment treatment agent [12] was used to make a liquid crystal MLC-6608 (manufactured by Merck Japan Co.). Subsequently, the post tilt angle was measured after the liquid crystal injection at an indentation amount of 0.3 mm for the rubbing treatment and after the heat treatment at 120 캜 for 5 hours. When the alignment uniformity of the liquid crystal was confirmed by observing a polarizing microscope with respect to the liquid crystal cell after the initial and each heat treatment, no alignment defect was found in any of the liquid crystal cells, and the liquid crystal was uniformly oriented.

The pretilt angle was measured at the initial stage after the injection of the liquid crystal and after the heat treatment at 120 ° C for 5 hours for the liquid crystal cell produced in the same manner as above except that the indentation amount was set to 0.1 mm. For these liquid crystal cells, alignment homogeneity of the liquid crystal was confirmed by observation with a polarizing microscope. As a result, none of the liquid crystal cells had orientation defects and the liquid crystal was uniformly oriented.

The measurement results of the pretilt angle are shown in Table 1.

(Example 8)

NMP (17.6 g) was added to the polyimide powder (E) (3.00 g) obtained in Synthesis Example 5 and dissolved by stirring at 80 占 폚 for 40 hours. Oxetane (A) (0.15 g), NMP (5.51 g) and BCS (26.3 g) were added to this solution and stirred to obtain a liquid crystal alignment treatment agent [13].

A liquid crystal cell was prepared in the same manner as in Example 1 except that the obtained liquid crystal alignment treatment agent [13] was used to make a liquid crystal MLC-6608 (manufactured by Merck Japan Co.). Subsequently, the post tilt angle was measured after the liquid crystal injection at an indentation amount of 0.3 mm for the rubbing treatment and after the heat treatment at 120 캜 for 5 hours. When the alignment uniformity of the liquid crystal was confirmed by observing a polarizing microscope with respect to the liquid crystal cell after the initial and each heat treatment, no alignment defect was found in any of the liquid crystal cells, and the liquid crystal was uniformly oriented.

The pretilt angle was measured at the initial stage after the injection of the liquid crystal and after the heat treatment at 120 ° C for 5 hours for the liquid crystal cell produced in the same manner as above except that the indentation amount was set to 0.1 mm. For these liquid crystal cells, alignment homogeneity of the liquid crystal was confirmed by observation with a polarizing microscope. As a result, none of the liquid crystal cells had orientation defects and the liquid crystal was uniformly oriented.

The measurement results of the pretilt angle are shown in Table 1.

(Example 9)

NMP (18.4 g) was added to the polyimide powder (F) (3.12 g) obtained in Synthesis Example 6 and dissolved by stirring at 80 占 폚 for 40 hours. Oxetane (A) (0.31 g), NMP (6.80 g) and BCS (28.6 g) were added to this solution and stirred to obtain a liquid crystal alignment treatment agent [14].

A liquid crystal cell was prepared in the same manner as in Example 1 except that the obtained liquid crystal alignment treatment agent [14] was used to change the liquid crystal to MLC-6608 (manufactured by Merck Japan Co.). Subsequently, the post tilt angle was measured after the liquid crystal injection at an indentation amount of 0.3 mm for the rubbing treatment and after the heat treatment at 120 캜 for 5 hours. When the alignment uniformity of the liquid crystal was confirmed by observing a polarizing microscope with respect to the liquid crystal cell after the initial and each heat treatment, no alignment defect was found in any of the liquid crystal cells, and the liquid crystal was uniformly oriented.

The measurement results of the pretilt angle are shown in Table 1.

(Example 10)

NMP (17.9 g) was added to the polyimide powder (F) (3.04 g) obtained in Synthesis Example 6 and dissolved by stirring at 80 占 폚 for 40 hours. Oxetane (A) (0.15 g), NMP (5.51 g) and BCS (26.6 g) were added to this solution and stirred to obtain a liquid crystal alignment treatment agent [15].

A liquid crystal cell was prepared in the same manner as in Example 1 except that the obtained liquid crystal alignment treatment agent [15] was used to make a liquid crystal MLC-6608 (manufactured by Merck Japan Co.). Subsequently, the post tilt angle was measured after the liquid crystal injection at an indentation amount of 0.3 mm for the rubbing treatment and after the heat treatment at 120 캜 for 5 hours. When the alignment uniformity of the liquid crystal was confirmed by observing a polarizing microscope with respect to the liquid crystal cell after the initial and each heat treatment, no alignment defect was found in any of the liquid crystal cells, and the liquid crystal was uniformly oriented.

The measurement results of the pretilt angle are shown in Table 1.

(Example 11)

NMP (17.5 g) was added to the polyimide powder (G) (2.98 g) obtained in Synthesis Example 7 and dissolved by stirring at 80 占 폚 for 40 hours. Oxetane (A) (0.30 g), NMP (6.61 g) and BCS (27.3 g) were added to this solution and stirred to obtain a liquid crystal alignment treatment agent [16].

A liquid crystal cell was prepared in the same manner as in Example 1 except that the obtained liquid crystal alignment treatment agent [16] was used instead of the liquid crystal MLC-6608 (manufactured by Merck Japan Ltd.). Subsequently, the post tilt angle was measured after the liquid crystal injection at an indentation amount of 0.3 mm for the rubbing treatment and after the heat treatment at 120 캜 for 5 hours. When the alignment uniformity of the liquid crystal was confirmed by observing a polarizing microscope with respect to the liquid crystal cell after the initial and each heat treatment, no alignment defect was found in any of the liquid crystal cells, and the liquid crystal was uniformly oriented.

The measurement results of the pretilt angle are shown in Table 1.

(Example 12)

NMP (17.7 g) was added to the polyimide powder (G) (3.01 g) obtained in Synthesis Example 7 and dissolved by stirring at 80 占 폚 for 40 hours. Oxetane (C) (0.15 g), NMP (5.41 g) and BCS (26.3 g) were added to this solution and stirred to obtain a liquid crystal alignment treatment agent [17].

A liquid crystal cell was prepared in the same manner as in Example 1 except that the obtained liquid crystal alignment treatment agent [17] was used to make a liquid crystal MLC-6608 (manufactured by Merck Japan Co.). Subsequently, the post tilt angle was measured after the liquid crystal injection at an indentation amount of 0.3 mm for the rubbing treatment and after the heat treatment at 120 캜 for 5 hours. When the alignment uniformity of the liquid crystal was confirmed by observing a polarizing microscope with respect to the liquid crystal cell after the initial and each heat treatment, no alignment defect was found in any of the liquid crystal cells, and the liquid crystal was uniformly oriented.

The measurement results of the pretilt angle are shown in Table 1.

(Comparative Example 6)

NMP (17.1 g) was added to the polyimide powder (E) (2.91 g) obtained in Synthesis Example 5 and dissolved by stirring at 80 占 폚 for 40 hours. NMP (4.18 g) and BCS (26.3 g) were added to this solution and stirred to obtain a liquid crystal alignment treatment agent [18].

A liquid crystal cell was prepared in the same manner as in Example 1 except that the obtained liquid crystal alignment treating agent [18] was used instead of the liquid crystal MLC-6608 (manufactured by Merck Japan Co.). Subsequently, the post tilt angle was measured after the liquid crystal injection at an indentation amount of 0.3 mm for the rubbing treatment and after the heat treatment at 120 캜 for 5 hours. When the alignment uniformity of the liquid crystal was confirmed by observing a polarizing microscope with respect to the liquid crystal cell after the initial and each heat treatment, no alignment defect was found in any of the liquid crystal cells, and the liquid crystal was uniformly oriented.

The measurement results of the pretilt angle are shown in Table 1.

(Comparative Example 7)

NMP (17.9 g) was added to the polyimide powder (F) (3.05 g) obtained in Synthesis Example 6 and dissolved by stirring at 80 占 폚 for 40 hours. NMP (4.46 g) and BCS (25.4 g) were added to this solution and stirred to obtain a liquid crystal alignment treatment agent [19].

A liquid crystal cell was prepared in the same manner as in Example 1 except that the obtained liquid crystal alignment treatment agent [19] was used to change the liquid crystal to MLC-6608 (manufactured by Merck Japan Co.). Subsequently, the post tilt angle was measured after the liquid crystal injection at an indentation amount of 0.3 mm for the rubbing treatment and after the heat treatment at 120 캜 for 5 hours. When the alignment uniformity of the liquid crystal was confirmed by observing a polarizing microscope with respect to the liquid crystal cell after the initial and each heat treatment, no alignment defect was found in any of the liquid crystal cells, and the liquid crystal was uniformly oriented.

The measurement results of the pretilt angle are shown in Table 1.

(Comparative Example 8)

NMP (17.7 g) was added to the polyimide powder (G) (3.00 g) obtained in Synthesis Example 7 and dissolved by stirring at 80 占 폚 for 40 hours. NMP (4.35 g) and BCS (25.1 g) were added to this solution and stirred to obtain a liquid crystal alignment treatment agent [20].

A liquid crystal cell was prepared in the same manner as in Example 1 except that the obtained liquid crystal alignment treatment agent [20] was used to make a liquid crystal MLC-6608 (manufactured by Merck Japan Ltd.). Subsequently, the post tilt angle was measured after the liquid crystal injection at an indentation amount of 0.3 mm for the rubbing treatment and after the heat treatment at 120 캜 for 5 hours. When the alignment uniformity of the liquid crystal was confirmed by observing a polarizing microscope with respect to the liquid crystal cell after the initial and each heat treatment, no alignment defect was found in any of the liquid crystal cells, and the liquid crystal was uniformly oriented.

The measurement results of the pretilt angle are shown in Table 1.

(Comparative Example 9)

NMP (17.7 g) was added to the polyimide powder (F) (3.01 g) obtained in Synthesis Example 6 and dissolved by stirring at 80 占 폚 for 40 hours. To this solution, epoxy (A) (0.60 g), NMP (8.80 g) and BCS (30.0 g) were added and stirred to obtain a liquid crystal alignment treating agent [21].

A liquid crystal cell was prepared in the same manner as in Example 1 except that the obtained liquid crystal alignment treatment agent [21] was used to make a liquid crystal MLC-6608 (manufactured by Merck Japan Co.). Subsequently, the pretilt angle was measured after the heat treatment at 120 ° C for 5 hours in the initial stage after injecting the liquid crystal at the press-in amount of 0.3 mm for the rubbing treatment. In the initial state of the liquid crystal cell, a so-called flow orientation in which the liquid crystal was aligned in the direction in which the liquid crystal flowed during liquid crystal injection was observed. In addition, at this stage after the heat treatment, this flow orientation was not solved, and a disclination line was generated by the heat treatment. Since such orientation defects have occurred, the pretilt angle of the liquid crystal cell can not be measured.

In addition, except that the indentation amount was set to 0.1 mm, the pretilt angle after the liquid crystal injection of the liquid crystal cell prepared as described above and the heat treatment at 120 ° C for 5 hours were measured, and the orientation of flow was observed in the initial state . After the heat treatment, the flow orientation was not solved, and a disclination line was generated. Therefore, the pretilt angle could not be measured.

The measurement results of the pretilt angle are shown in Table 1.

(Comparative Example 10)

NMP (17.5 g) was added to the polyimide powder (F) (3.00 g) obtained in Synthesis Example 6 and dissolved by stirring at 80 占 폚 for 40 hours. To this solution, epoxy (A) (0.30 g), NMP (6.71 g) and BCS (27.5 g) were added and stirred to obtain a liquid crystal alignment treatment agent [22].

A liquid crystal cell was prepared in the same manner as in Example 1 except that the obtained liquid crystal alignment treatment agent [22] was used to change the liquid crystal to MLC-6608 (Merck Japan). Subsequently, the pretilt angle was measured after the heat treatment at 120 ° C for 5 hours in the initial stage after injecting the liquid crystal at the press-in amount of 0.3 mm for the rubbing treatment. When the alignment uniformity of the liquid crystal was confirmed by observing a polarizing microscope with respect to the liquid crystal cell after the initial and each heat treatment, no alignment defect was found in any of the liquid crystal cells, and the liquid crystal was uniformly oriented.

In addition, except that the indentation amount was set to 0.1 mm, the pretilt angle after the liquid crystal injection of the liquid crystal cell prepared as described above and the heat treatment at 120 ° C for 5 hours were measured, and the orientation of flow was observed in the initial state . After the heat treatment, the flow orientation was not solved, and a disclination line was generated. Therefore, the pretilt angle could not be measured.

The measurement results of the pretilt angle are shown in Table 1.

(Comparative Example 11)

NMP (17.8 g) was added to the polyimide powder (F) (3.03 g) obtained in Synthesis Example 6 and dissolved by stirring at 80 占 폚 for 40 hours. Epoxy (A) (0.15 g), NMP (5.60 g) and BCS (26.3 g) were added to this solution and stirred to obtain a liquid crystal alignment treatment agent [23].

A liquid crystal cell was prepared in the same manner as in Example 1 except that the obtained liquid crystal alignment treatment agent [23] was used and MLC-6608 (manufactured by Merck Japan Co., Ltd.) was used as the liquid crystal. Subsequently, the pretilt angle was measured after the heat treatment at 120 ° C for 5 hours in the initial stage after injecting the liquid crystal at the press-in amount of 0.3 mm for the rubbing treatment. When the alignment uniformity of the liquid crystal was confirmed by observing a polarizing microscope with respect to the liquid crystal cell at the initial stage and after each heat treatment, none of the liquid crystal cells had orientation defects and the liquid crystal was uniformly oriented.

In addition, except that the indentation amount was set to 0.1 mm, the pretilt angle after the liquid crystal injection of the liquid crystal cell prepared as described above and the heat treatment at 120 ° C for 5 hours were measured, and the orientation of flow was observed in the initial state . After the heat treatment, the flow orientation was not solved, and a disclination line was generated. Therefore, the pretilt angle could not be measured.

The measurement results of the pretilt angle are shown in Table 1.

(Comparative Example 12)

NMP (17.1 g) was added to the polyimide powder (F) (2.93 g) obtained in Synthesis Example 6 and dissolved by stirring at 80 占 폚 for 40 hours. To this solution, epoxy (B) (0.30 g), NMP (5.50 g) and BCS (25.7 g) were added and stirred to obtain a liquid crystal alignment treatment agent [24].

A liquid crystal cell was prepared in the same manner as in Example 1 except that the obtained liquid crystal alignment treatment agent [24] was used to change the liquid crystal to MLC-6608 (manufactured by Merck Japan Co.). Subsequently, the pretilt angle was measured after the heat treatment at 120 ° C for 5 hours in the initial stage after injecting the liquid crystal at the press-in amount of 0.3 mm for the rubbing treatment. When the alignment uniformity of the liquid crystal was confirmed by observing a polarizing microscope with respect to the liquid crystal cell at the initial stage and after each heat treatment, none of the liquid crystal cells had orientation defects and the liquid crystal was uniformly oriented.

In addition, except that the indentation amount was set to 0.1 mm, the pretilt angle after the liquid crystal injection of the liquid crystal cell prepared as described above and the heat treatment at 120 ° C for 5 hours were measured, and the orientation of flow was observed in the initial state . After the heat treatment, the flow orientation was not solved, and a disclination line was generated. Therefore, the pretilt angle could not be measured.

The measurement results of the pretilt angle are shown in Table 1.

-: Not evaluated

* 1: A polarizing microscope observation revealed a flow direction in the liquid crystal cell.

* 2: By polarization microscope observation, the liquid crystal cell showed a flow orientation and a disclination line.

* 3: Disclination line was observed in the liquid crystal cell by observation with a polarizing microscope.

(Each pretilt angle is an average value obtained by measuring the center of the liquid crystal cell and three points of 1 cm above and below)

From the above results, it was confirmed that the liquid crystal alignment film obtained from the liquid crystal alignment treatment agent of the present invention was comparable to those of Examples 1 to 12 containing a specific crosslinkable compound, Comparative Examples 1 and 2 containing no crosslinkable compound and Comparative Examples 6 to 8 The orientation of the liquid crystal did not change, and the stability of the pretilt angle was greatly improved by the change of the pretilt angle after the high temperature treatment to less than 1 degree. On the other hand, as in Comparative Examples 3 to 5 and Comparative Examples 9 to 12, when an epoxy based crosslinking compound was used in place of the specific crosslinking compound in the present invention, orientation defects were observed. Particularly, in these Comparative Examples, orientation defects occurred when the amount of indentation of the rubbing treatment was low.

By using the liquid crystal alignment treatment agent of the present invention, a liquid crystal alignment film excellent in the stability of the pretilt angle of the liquid crystal can be obtained. The liquid crystal display element having this liquid crystal alignment film is excellent in reliability, and thus is useful for a TN device, an STN device, a TFT liquid crystal device, and a vertically aligned liquid crystal display device.

The entire contents of the specification, claims, and abstract of Japanese Patent Application No. 2006-297244 filed on November 1, 2006 are hereby incorporated herein by reference as the disclosure of the present specification.

Claims (10)

A liquid crystal alignment treatment agent comprising the following components (A) and (B). (A): at least one kind of polymer selected from the group consisting of polyamic acid and polyimide Component (B): A crosslinkable compound having at least two oxetane groups represented by the following formula [1] in the molecule. [Chemical Formula 1]

The method according to claim 1, (B) is a compound represented by the following formula [2]. (2)

(Wherein X ₁ represents N, NH, CO, O, S, SO ₂ , Si, silsesquioxane, polysiloxane or an organic group having 1 to 20 carbon atoms, O, S, SO ₂ , or an organic group having 1 to 20 carbon atoms, and X ₂ and X ₃ each independently represent a single bond, NH, CO, O, S, (N, O, S, Si) may be contained, and Y ₁ and Y ₂ each independently represent an organic group having 1 to 20 carbon atoms. M and n each independently represent an integer of 0 to 20, and m + n represents an integer of 2 to 20, The method according to claim 1, (B) is a compound represented by the following formula [3]. (3)

X ₂ and X ₃ each independently represent a single bond, NH, CO, O, S, SO ₂ or an organic group having 1 to 20 carbon atoms and heteroatoms (N, O , S, and Si), Y ₁ and Y ₂ each independently represent an organic group having 1 to 20 carbon atoms, and the organic group may contain hetero atoms (N, O, S, Si) ₁ is a single _{bond, NH, N (CH 3)} , NHCO, CONH, NHCONH, CO, COO, O, S, SO 2, CF 2, C (CF 3) 2, Si (CH 3) 2, OSi (CH _{3) 2, Si (CH 3} ) 2 O, OSi (CH 3) 2 O, or an alkyl group having a carbon number of 1 to 10, and m, n are each independently an integer of 0 to 10, and m + n is An integer of 2 to 10) The method according to claim 1, (B) is a compound represented by the following formula [4]. [Chemical Formula 4]

(Formula [4] of, X ₁ is _{NH, N (CH 3),} NHCO, CONH, NHCONH, CO, COO, OCO, O, S, SO 2, CF 2, C (CF 3) 2, Si (CH ₃ ) ₂ , OSi (CH ₃ ) ₂ , Si (CH ₃ ) ₂ O, or OSi (CH ₃ ) ₂ O and Y ₁ and Y ₂ each independently represent an alkyl group having 1 to 10 carbon atoms. The method according to claim 1, (B) is a compound represented by the following formula [5]. [Chemical Formula 5]

(In the formula [5], X ₁ is N, an aliphatic ring having 1 to 20 carbon atoms, an aromatic ring having 1 to 20 carbon atoms, or an alkylene having 1 to 20 carbon atoms, Y ₁ and Y ₂ each represent an alkyl group having 1 to 10 carbon atoms M, n is an integer of 0 to 20, and m + n is an integer of 2 to 20) The method according to claim 1, Wherein the content of the component (B) is 0.1 to 150 parts by mass based on 100 parts by mass of the component (A). The method according to claim 1, A liquid crystal alignment treatment agent further comprising an organic solvent. 8. The method of claim 7, Wherein the organic solvent contains 5 to 80 mass% of a solvent having a low surface tension in the total organic solvent. A liquid crystal alignment film obtained by the liquid crystal alignment treatment agent according to any one of claims 1 to 8. A liquid crystal display element having the liquid crystal alignment film according to claim 9.