TWI605091B - Liquid crystal alignment agent, liquid crystal alignment film and liquid crystal display element - Google Patents

Description

Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element

The present invention relates to a liquid crystal alignment agent, a liquid crystal alignment film, and a liquid crystal display element containing a polymer obtained by using a diamine compound having a specific structure.

The liquid crystal alignment film is a constituent member used for controlling the alignment state of the liquid crystal in the liquid crystal display element.

In the formation of the liquid crystal alignment film in the liquid crystal display device, for example, a polymer obtained by dissolving a polymer such as a polyimide or a polymerizable polyimide precursor such as polyacrylamide or a soluble polyimine in a solvent is used. Orientation treatment agent (also referred to as liquid crystal alignment agent). Next, it is applied onto a TFT (thin film transistor) substrate, a glass substrate to which ITO (tin-doped indium oxide) is attached, or the like, and is fired to form a film of a polymer. At present, a so-called polyimine-based liquid crystal alignment film is mainly used as a liquid crystal alignment film.

In recent years, with the high precision of liquid crystal display elements, it is required to suppress the contrast of the liquid crystal display elements from being lowered or to reduce the afterimage phenomenon. Therefore, the liquid crystal alignment film used requires various performances in addition to the image control of the liquid crystal. Such as increasing the voltage holding ratio or reducing the application of DC voltage The residual charge accelerates the relaxation of the accumulated residual charge due to the DC voltage, and is considered to be quite important.

In the polyimine-based liquid crystal alignment film, as a problem of improving the residual charge due to the application of the DC voltage, and shortening the time until the afterimage of the liquid crystal display element due to the DC voltage disappears, In addition to an amino acid or a ruthenium group containing a quinone imine group, a liquid crystal alignment agent containing a tertiary amine having a specific structure is known (see, for example, Patent Document 1), and a specific pyridine or imidazole skeleton is used in the raw material. A liquid crystal alignment agent of a soluble polyimine of a diamine compound (see, for example, Patent Document 2).

Usually, N-methylpyrrolidone is used as a solvent in the liquid crystal alignment agents. However, N-methylpyrrolidone is excellent in solubility and can dissolve the polymer well. On the other hand, when the liquid crystal alignment agent is ink-jet-coated, the protruding portion is often dissolved. Therefore, a liquid crystal alignment agent which does not use N-methylpyrrolidone as a solvent is required.

[Previous Technical Literature]

Patent Document 1: Japanese Patent Laid-Open No. Hei 9-316200

Patent Document 2: Japanese Patent Laid-Open No. Hei 10-104633

However, polyamic acid and/or polyimine using a specific diamine compound having an aromatic heterocyclic ring such as the above pyridine or imidazole skeleton or the like (hereinafter sometimes referred to simply as a polymer) is often poor in solubility in a solvent other than N-pyrrolidone.

Therefore, in the polymer used for the formation of the liquid crystal alignment film, it is required to achieve excellent solubility in a manner other than a solvent other than N-methylpyrrolidone.

An object of the present invention is to provide a liquid crystal alignment agent containing a polymer obtained by forming a compound for use in a polymer having excellent solubility, a liquid crystal alignment film formed using the liquid crystal alignment agent, and a voltage retention property and a residual charge derived therefrom. A liquid crystal display element having excellent afterimage characteristics.

The present inventors conducted active research to achieve the above object, and found a specific diamine compound of the present invention having a novel structure, and found that a liquid crystal alignment agent containing a polymer obtained by using the diamine compound as a component can achieve the above object.

That is, the present invention has the following gist.

A liquid crystal alignment agent characterized by comprising at least one polymer selected from the group consisting of a polyimide precursor and a polyimine obtained by subjecting the polyimide precursor to ruthenium imidization. The polyimine precursor is obtained by using one or more kinds of diamine components selected from the group consisting of diamine compounds represented by the following formulas (1) and (2). (Boc represents tert-butoxy carbonyl group, R ¹ is a single bond, -CH ₂ - or -CH ^₂ CH ₂ -, R ₂ is a -O -, - COO -, - OCO -, - NHCO -, - CONH- , -NH-, -N(CH ₃ )-, -CON(CH ₃ )-, -N(CH ₃ )CO- or -N(COMe)- (here, Me represents a methyl group), R ³ is a single a bond or a divalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, wherein any hydrogen atom of the aliphatic hydrocarbon group may be substituted with a carboxyl group, an ester group or a mercaptoamine group, and R ⁴ is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. , R ⁵ is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms), ^{(Boc, R 1, R 2} , Boc R 3, R 4 and R ⁵ in the formula (1) ^{of, R 1, R 2, R} 3, and R is defined the same as R ⁴ of ^5).

2. The liquid crystal alignment agent according to the above-mentioned item 1, wherein the polyimine precursor is one or more selected from the group consisting of diamine compounds represented by the formulas (1) and (2). The polyamine acid obtained by reacting the diamine component with tetracarboxylic dianhydride.

3. The liquid crystal alignment agent according to the above 1 or 2, wherein the diamine compound is one or more selected from the group consisting of the following formulas (3) and (4). (Boc represents a third butoxycarbonyl group, and Me represents a methyl group).

4. The liquid crystal alignment agent according to any one of the above 1 to 3, wherein the content of the polymer is 1 to 20% by weight in the liquid crystal alignment agent.

A liquid crystal alignment film obtained by coating the liquid crystal alignment agent according to any one of the above 1 to 4, which is dried and sintered.

6. The liquid crystal alignment film according to the above 5, wherein the sintering temperature is 50 to 300 °C.

7. The liquid crystal alignment film according to the above 5 or 6, wherein the film thickness after sintering is 5 to 300 nm.

A liquid crystal display element comprising the liquid crystal alignment film according to any one of the above 5 to 7.

A diamine compound represented by any one of the following formulas (1) and (2), (Boc represents a third butoxycarbonyl group, R ¹ is a single bond, -CH ₂ - or -CH ₂ CH ₂ -, and R ² is -O-, -COO-, -OCO-, -NHCO-, -CONH- , -NH-, -N(CH ₃ )-, -CON(CH ₃ )-, -N(CH ₃ )CO- or -N(COMe)- (here, Me represents a methyl group), R ³ is a single a bond or a divalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, wherein any hydrogen atom of the aliphatic hydrocarbon group may be substituted with a carboxyl group, an ester group or a mercaptoamine group, and R ⁴ is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. , R ⁵ is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms), ^{(Boc, R 1, R 2} , Boc R 3, R 4 and R ⁵ in the formula (1) ^{of, R 1, R 2, R} 3, and R is defined the same as R ⁴ of ^5).

10. The diamine compound according to the above 9, wherein R ⁵ in the formula (1) and the formula (2) is hydrogen.

11. The diamine compound according to the above 9 or 10, wherein R ⁴ in the formula (1) and the formula (2) is a methyl group.

A diamine compound represented by any one of the following formulas (3) and (4), (Boc represents a third butoxycarbonyl group, and Me represents a methyl group).

A polymer obtained by using one or more selected from the group consisting of the diamine compounds described in any one of the above 9 to 12.

By using the diamine compound of the present invention, a polymer excellent in solubility is obtained, and has a shape of a liquid crystal alignment agent containing the polymer. The liquid crystal display element of the liquid crystal alignment film has excellent voltage retention characteristics and after-image characteristics derived from residual electric charge, and can be utilized as a display device which is lightweight, thin, and low in power consumption.

Fig. 1 is an X-ray structural analysis image of a compound (DA-A-2) of a precursor of a diamine compound.

A polyamine compound (also referred to as a specific diamine compound) using the compound of the present invention, and a polyimide precursor formed as a polymer and/or a polyamidene precursor thereof The quinone imine has excellent solubility and can also be dissolved in a solvent other than N-methylpyrrolidone. That is, at least a portion of a liquid crystal alignment agent using a solvent other than N-methylpyrrolidone can be provided.

Further, a polyamine compound using a diamine compound of the present invention and containing a polyimine precursor formed as a polymer and/or a polyimide which is imidized by a polyimide precursor thereof The liquid crystal alignment film obtained by the liquid crystal alignment agent can promote the charge movement in the liquid crystal alignment film.

Further, it has a high voltage holding ratio and can accelerate the relaxation of the accumulated residual charge due to the DC voltage even after exposure for a long time at a high temperature.

Therefore, it has a diamine compound containing the use of the present invention. A liquid crystal display element of a liquid crystal alignment film obtained by using a polyimine precursor and/or a polyimine as a liquid crystal alignment treatment agent of a polymer is excellent in reliability, and can be preferably used in a high-definition liquid crystal television or the like for a large screen. in.

Hereinafter, the compound of the present invention, that is, a specific diamine compound, a polymer obtained by using the specific diamine compound, a liquid crystal alignment agent containing the polymer as a component, a liquid crystal alignment film formed using the same, and the liquid crystal alignment film The liquid crystal display element will be described.

<Specific diamine compound>

The specific diamine compound of the present invention is a compound represented by any one of the following formulas (1) and (2).

Further, in the following formulas (1) and (2), Boc represents a third butoxycarbonyl group, and the same applies to the following formulae.

(R ¹ is a single bond, -CH ₂ - or -CH ₂ CH ₂ -, R ² is -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, -N(CH ₃ ) -, -CON(CH ₃ )-, -N(CH ₃ )CO- or -N(COMe)- (here, Me represents a methyl group), R ³ is a single bond or a carbon number of 1 to 20 a valent aliphatic hydrocarbon group, wherein any hydrogen atom of the aliphatic hydrocarbon group may be substituted with a carboxyl group, an ester group or a mercaptoamine group, R ⁴ is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and R ⁵ is a hydrogen atom or carbon Number 1 to 20 alkyl).

^{(R 1, R 2, R} R 3, R 4 and R ⁵ in the formula (1) of ^1, R ^2, R ^3, and R is defined the same as R ⁴ of ^5).

Among the specific diamine compounds represented by the above formulas (1) and (2), the diamine compounds represented by the following formulas (3) and (4) are preferred. Further, in the following formulas (3) and (4), Me represents a methyl group, and the same applies to the following various formulae.

<Synthesis method and raw material compound of specific diamine compound>

The method for producing the specific diamine compound represented by any one of the above formulas (1) and (2) of the present invention is not particularly limited.

For example, the dinitro compound represented by the following formula (5) and formula (6) is prepared by converting the nitro group to an amine group.

(R ¹ is a single bond, -CH ₂ - or -CH ₂ CH ₂ -, R ² is -O-, -COO-, -OCO-, -NHCO-, -CONH-, -NH-, -N(CH ₃ ) -, -CON(CH ₃ )-, -N(CH ₃ )CO- or -N(COMe)- (here, Me represents a methyl group), R ³ is a single bond or a carbon number of 1 to 20 a valent aliphatic hydrocarbon group, wherein any hydrogen atom of the aliphatic hydrocarbon group may be substituted with a carboxyl group, an ester group or a mercaptoamine group, R ⁴ is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and R ⁵ is a hydrogen atom or carbon Number 1 to 20 alkyl).

In the dinitro compound represented by the above formula (5) and formula (6), the synthesis of the diamine compound represented by the above formula (3) and formula (4) is represented by the following formula (7) and The dinitro compound represented by the formula (8) is preferred.

Reduction of the dinitro compound represented by the above formula (7) and formula (8), for example, by the dinitro compound of the formula (5) and the above formula (6) The method is not particularly limited, and generally, palladium-carbon, platinum oxide, Raney nickel, iron, tin chloride, platinum black, lanthanum-alumina, platinum sulfide carbon or the like can be used as a catalyst, in acetic acid B. In a solvent such as an ester, toluene, tetrahydrofuran, dioxane or an alcohol, a reaction using hydrogen, hydrazine, hydrogen chloride, ammonium chloride or the like is carried out.

<polyglycine>

The polymer of the present invention is composed of a polyimine precursor obtained by using a diamine component containing the above specific diamine compound, and a polyimine obtained by imidating the polyimine precursor quinone. Selecting at least one polymer, in particular, a polylysine obtained by reacting a diamine component containing the above specific diamine compound with a tetracarboxylic dianhydride, and a polycondensation obtained by subjecting the polyamic acid to dehydration ring closure Yttrium.

These polyimine precursors and polyimine are contained in a liquid crystal alignment agent, and can be effectively used as a polymer for obtaining a liquid crystal alignment film.

In the liquid crystal alignment film obtained by using the polymer of the present invention, the more the content ratio of the specific diamine compound in the diamine component for forming the liquid crystal alignment film, the higher the voltage holding ratio and the long-time exposure even at a high temperature. After that, the relaxation of the accumulated residual charge due to the DC voltage can still be accelerated.

In order to improve the above electrical characteristics, it is preferred that 5 mol% or more of the diamine component contained in the liquid crystal alignment agent is a specific diamine compound. More preferably, 10 mol% or more of the diamine component is a specific diamine compound, and more preferably 15 mol% or more.

Further, 100 mol% of the diamine component may be a specific diamine compound, but the specific diamine compound is preferably 80 mol% of the diamine component from the viewpoint of uniform coatability when the liquid crystal alignment agent is applied. Hereinafter, it is preferably 70 mol% or less.

[Other diamine compounds]

In the present invention, in addition to the specific diamine compound, other diamine compounds may be used in combination as the diamine component for forming the polymer, within the range not impairing the effects of the present invention. Specific examples of other diamine compounds are listed below.

p-Benzyldiamine, 2,3,5,6-tetramethyl-p-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, m-phenylenediamine, 2,4-dimethyl Base-m-phenylenediamine, 2,5-diaminotoluene, 2,6-diaminotoluene, 2,5-diaminophenol, 2,4-diaminophenol, 3,5-diamine Phenolic, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6-diaminoisoxoxyl, 4,4'-diaminobiphenyl, 3 , 3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dihydroxy-4, 4'-Diaminobiphenyl, 3,3'-difluoro-4,4'-biphenyl, 3,3'-trifluoromethyl-4,4'-diaminobiphenyl, 3,4' -diaminobiphenyl, 3,3'-diaminobiphenyl, 2,2'-diaminobiphenyl, 2,3'-diaminobiphenyl, 4,4'-diaminodiphenyl Methane, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 2,2'-diaminodiphenylmethane, 2,3'-diamino Diphenylmethane, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 2,2'-di Aminodiphenyl ether, 2,3'-diaminodiphenyl ether, 4,4'-sulfonyldiphenylamine, 3,3'-sulfonate Mercaptodiphenylamine, bis(4-aminophenyl)decane, bis(3-aminophenyl)decane, dimethyl-bis(4-aminobenzene) Base) decane, dimethyl-bis(3-aminophenyl)decane, 4,4'-thiodiphenylamine, 3,3'-thiodiphenylamine, 4,4'-diaminodiphenyl Amine, 3,3'-diaminodiphenylamine, 3,4'-diaminodiphenylamine, 2,2'-diaminodiphenylamine, 2,3'-diaminodi Phenylamine, N-methyl(4,4'-diaminodiphenyl)amine, N-methyl(3,3'-diaminodiphenyl)amine, N-methyl (3,4 '-Diaminodiphenyl)amine, N-methyl(2,2'-diaminodiphenyl)amine, N-methyl(2,3'-diaminodiphenyl)amine, 4 , 4'-diaminobenzophenone, 3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone, 1,4-diaminonaphthalene, 2,2 '-Diaminobenzophenone, 2,3'-diaminobenzophenone, 1,5-diaminonaphthalene, 1,6-diaminonaphthalene, 1,7-diaminonaphthalene, 1,8-Diaminonaphthalene, 2,5-diaminonaphthalene, 2,6-diaminonaphthalene, 2,7-diaminonaphthalene, 2,8-diaminonaphthalene, 1,2-double (4-Aminophenyl)ethane, 1,2-bis(3-aminophenyl)ethane, 1,3-bis(4-aminophenyl)propane, 1,3-bis(3- Aminophenyl)propane, 1,4-bis(4-aminophenyl)butane, 1,4-bis(3-aminophenyl)butane, bis(3,5-diethyl-4) - Phenyl)methane, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenyl) Benzene, 1,3-bis(4-aminophenyl)benzene, 1,4-bis(4-aminobenzyl)benzene, 1,3-bis(4-aminophenoxy)benzene, 4 , 4'-[1,4-phenylenebis(methylene)]diphenylamine, 4,4'-[1,3-phenylenebis(methylene)]diphenylamine, 3,4'- [1,4-phenylphenylbis(methylene)]diphenylamine, 3,4'-[1,3-phenylenebis(methylene)]diphenylamine, 3,3'-[1,4 -phenylphenylbis(methylene)]diphenylamine, 3,3'-[1,3-phenylenebis(methylene)]diphenylamine, 1,4-phenylene bis[(4-amine) Phenyl)methanom, 1,4-phenylene bis[(3-aminophenyl) bridged methylene], 1,3-phenylene bis[(4-amino) benzene (methylene), 1,3-phenylene bis[(3-aminophenyl) bridged methylene], 1,4-phenylene bis(4-aminobenzoate), 1,4-phenylphenylbis(3-aminobenzoate), 1,3-phenylene bis(4-aminobenzoate), 1,3-phenylene bis(3-amine Benzoate), bis(4-aminophenyl)terephthalate, bis(3-aminophenyl)terephthalate, bis(4-aminophenyl)isophthalate Dicarboxylate, bis(3-aminophenyl)isophthalate, N,N'-(1,4-phenylene)bis(4-aminobenzamide), N,N '-(1,3-Extended phenyl)bis(4-aminobenzamide), N,N'-(1,4-phenylene)bis(3-aminobenzamide), N , N'-(1,3-phenylene) bis(3-aminobenzamide), N,N'-bis(4-aminophenyl)terephthalamide, N,N' - bis(3-aminophenyl)terephthalamide, N,N'-bis(4-aminophenyl)m-xylyleneamine, N,N'-bis(3-aminobenzene) Benzyl decylamine, 9,10-bis(4-aminophenyl)anthracene, 4,4'-bis(4-aminophenoxy)diphenylanthracene, 2,2'-double [4-(4-Aminophenoxy)phenyl]propane, 2,2'-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2'-bis (4 -aminophenyl)hexafluoropropane, 2, 2'-bis(3-aminophenyl)hexafluoropropane, 2,2'-bis(3-amino-4-methylphenyl)hexafluoropropane, 2,2'-bis(4-amino group Phenyl)propane, 2,2'-bis(3-aminophenyl)propane, 2,2'-bis(3-amino-4-methylphenyl)propane, 1,3-bis(4- Aminophenoxy)propane, 1,3-bis(3-aminophenoxy)propane, 1,4-bis(4-aminophenoxy)butane, 1,4-bis(3-amine Phenoxy)butane, 1,5-bis(4-aminophenoxy)pentane, 1,5-bis(3-aminophenoxy)pentane, 1,6-bis (4- Aminophenoxy)hexane, 1,6-bis(3-aminophenoxy)hexane, 1,7-bis(4-aminophenoxy)heptane, 1,7-(3- Aminophenoxy)heptane, 1,8-bis(4-aminophenoxy)octane, 1,8-bis(3-aminophenoxy)octane, 1,9-bis(4-aminophenoxy)decane 1,9-bis(3-aminophenoxy)decane, 1,10-(4-aminophenoxy)decane, 1,10-(3-aminophenoxy)decane, 1,11-(4-Aminophenoxy)undecane, 1,11-(3-aminophenoxy)undecane, 1,12-(4-aminophenoxy) Dioxane, 1,12-(3-aminophenoxy)dodecane, bis(4-aminocyclohexyl)methane, bis(4-amino-3-methylcyclohexyl)methane, 1 , 3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1, 8-Diaminooctane, 1,9-diaminodecane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododeca Alkane, etc.

Further, examples of the other diamine compound include a diamine compound having an alkyl group, a fluorine-containing alkyl group, an aromatic ring, an aliphatic ring, a hetero ring, and a cyclic substituent formed therefrom as a diamine side chain. Specific examples of the diamine compound include diamine compounds represented by the following formulas [DA1] to [DA26].

In the above formula [DA1] to [DA5], R ¹¹ is an alkyl group having 1 to 22 carbon atoms or a fluorine-containing alkyl group.

In the above formula [DA6]~[DA9], R ¹² is -COO-, -OCO-, -CONH-, -NHCO-, -CH ₂ -, -O-, -CO- or -NH-, and R ¹³ is An alkyl group having 1 to 22 carbon atoms or a fluorine-containing alkyl group.

In the above formula [DA10] and formula [DA11], R ¹⁴ is -O-, -OCH ₂ -, -CH ₂ O-, -COOCH ₂ -, or -CH ₂ OCO-.

R ¹⁵ is an alkyl group having 1 to 22 carbon atoms, an alkoxy group, a fluorine-containing alkyl group or a fluorine-containing alkoxy group.

In the above formula [DA12]~[DA14], R ¹⁶ is -COO-, -OCO-, -CONH-, -NHCO-, -COOCH ₂ -, -CH ₂ OCO-, -CH ₂ O-, -OCH ₂ -or-CH ₂ -.

R ¹⁷ is an alkyl group having 1 to 22 carbon atoms, an alkoxy group, a fluorine-containing alkyl group or a fluorine-containing alkoxy group.

In the above formula [DA15] and formula [DA16], R ¹⁸ is -COO-, -OCO-, -CONH-, -NHCO-, -COOCH ₂ -, -CH ₂ OCO-, -CH ₂ O-, -OCH ₂ -, -CH ₂ -, -O-, or -NH-.

R ¹⁹ is a fluorine group, a cyano group, a trifluoromethyl group, a nitro group, an azo group, a decyl group, an ethyl group, an ethoxy group, or a hydroxyl group.

Further, the other diamine compound is exemplified by a diamine sulfoxane represented by the following formula [DA27].

In the above formula [DA27], m is an integer of 1 to 10.

The other diamine compound may be used in combination with one or two or more kinds of the liquid crystal alignment film, the voltage retention, and the charge accumulation when the liquid crystal alignment film is formed by using a liquid crystal alignment agent containing a polymer.

[tetracarboxylic dianhydride]

The polylysine of the polymer of the present invention can be synthesized by reacting a diamine component containing the above specific diamine compound with a tetracarboxylic dianhydride.

The tetracarboxylic dianhydride for reacting the polyamine acid of the present invention with the diamine component is not particularly limited. Preferred specific examples are as follows.

Listed as pyromellitic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic acid Acid dianhydride, 2,3,6,7-nonanedicarboxylic dianhydride, 1,2,5,6-fluorene tetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2, 3,3',4-biphenyltetracarboxylic dianhydride, bis(3,4-dicarboxyphenyl)ether, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, double 3,4-dicarboxyphenyl)anthracene, bis(3,4-dicarboxyphenyl)methane, 2,2-bis(3,4-dicarboxyphenyl)propane, 1,1,1,3,3 ,3-hexafluoro-2,2-bis(3,4-dicarboxyphenyl)propane, bis(3,4-dicarboxyphenyl)dimethylnonane, bis(3,4-dicarboxyphenyl) Diphenyldecane, 2,3,4,5-pyridinetetracarboxylic dianhydride, 2,6-bis(3,4-dicarboxyphenyl)pyridine, 3,3',4,4'-diphenyl Terpene tetracarboxylic dianhydride, 3,4,9,10-insene naphthalene tetracarboxylic dianhydride, 1,3-diphenyl-1,2,3,4-cyclobutane tetracarboxylic dianhydride, oxygen Di-indenyltetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4, 5-cyclohexanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1, 2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclobutane Alkane tetracarboxylic dianhydride, 2,3,4,5-tetrahydrofuran tetracarboxylic acid , 3,4-dicarboxy-1-cyclohexyl succinic dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro- 1-naphthalene succinic dianhydride, bicyclo[3,3,0]octane-2,4,6,8-tetracarboxylic dianhydride, bicyclo[4,3,0]nonane-2,4,7, 9-tetracarboxylic dianhydride, bicyclo[4,4,0]nonane-2,4,7,9-tetracarboxylic dianhydride, bicyclo[4,4,0]nonane-2,4,8, 10-tetracarboxylic dianhydride, tricyclo[6.3.0.0<2,6>]undecane-3,5,9,11-tetracarboxylic dianhydride, 1,2,3,4-butane IV Carboxylic dianhydride, 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic dianhydride, bicyclo[2,2, 2] oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 5-(2,5-dioxotetrahydrofuranyl)-3-methyl-3-cyclohexane-1,2 -Dicarboxylic dianhydride, tetracyclic [6,2,1,1,0,2,7]dodecane-4,5,9,10-tetracarboxylic dianhydride, 3,5,6-tricarboxynorbornane-2:3,5 : 6 dicarboxylic dianhydride, 1,2,4,5-cyclohexane tetracarboxylic dianhydride, and the like.

The tetracarboxylic dianhydride may be one or more selected from the group consisting of a liquid crystal alignment film containing a polymer and a liquid crystal alignment property, a voltage holding property, and an accumulated electric charge.

A conventional synthesis method can be obtained by reacting a tetracarboxylic dianhydride with a diamine component to obtain the polyproline of the present invention.

For example, a method of reacting a tetracarboxylic dianhydride with a diamine component in an organic solvent. The reaction of the tetracarboxylic dianhydride with the diamine component is advantageously carried out in an organic solvent based on the ease of carrying out and the absence of by-products.

The organic solvent used for the reaction of the tetracarboxylic dianhydride and the diamine component is not particularly limited as long as the polyamic acid produced is dissolved. Specific examples thereof are as follows.

N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, dimethyl hydrazine, tetramethylurea , pyridine, dimethyl hydrazine, hexamethylarylene, γ-butyrolactone, isopropanol, methoxymethylpentanol, dipentene, ethyl amyl ketone, methyl decyl ketone, methyl Ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, butyl Carbitol, ethyl carbitol, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl Ether, propylene glycol, tert-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoacetate, 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 monoacetic acid Ester monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, diisopropyl ether, ethyl Butyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexanone, propyl ether, dihexyl ether, dioxane, n-hexane, n-pentane , n-octane, diethyl ether, cyclohexanone, ethylene carbonate, propylene carbonate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether, Methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, diglyme, 4-hydroxy-4-methyl-2-pentyl Ketones, etc. These may be used singly or in combination. Further, even if the solvent which does not dissolve the poly-proline is used, it may be mixed and used in the solvent in the range in which the produced polyamine is not precipitated.

Further, since the water in the organic solvent hinders the polymerization reaction and further causes hydrolysis of the produced polylysine, the organic solvent is preferably used by dehydration.

When the tetracarboxylic dianhydride and the diamine component are reacted in an organic solvent, the following method may be mentioned: a solution obtained by dispersing or dissolving a diamine component in an organic solvent, directly adding a tetracarboxylic dianhydride, or dispersing or dissolving a method of post-addition in an organic solvent; conversely, adding a diamine component to a solution obtained by dispersing or dissolving a tetracarboxylic dianhydride in an organic solvent The method of alternately adding a tetracarboxylic dianhydride and a diamine component, and the like can be used. Further, when the tetracarboxylic dianhydride or the diamine component is composed of a plurality of compounds, it may be reacted in a state of being mixed in advance, or may be reacted individually or sequentially, or the low-molecular weight of the individual reaction may be mixed and reacted into a high molecular weight body. The polymer was obtained.

The polymerization temperature in the reaction of the tetracarboxylic dianhydride with the diamine component may be selected from any temperature of from -20 to 150 ° C, preferably from -5 to 100 ° C.

Further, the reaction can be carried out at any concentration. However, when the concentration is too low, it is difficult to obtain a copolymer having a high molecular weight. When the concentration is too high, the viscosity of the reaction liquid is too high to be uniformly stirred, so that the tetracarboxylic dianhydride and the diamine component are reacted. The total concentration in the solution is preferably from 1 to 50% by mass, more preferably from 5 to 30% by mass. The initial stage of the reaction is carried out at a high concentration, and then an organic solvent can be added.

In the polymerization reaction for obtaining polyglycine, the ratio of the total number of moles of the tetracarboxylic dianhydride to the total number of moles of the diamine component is preferably from 0.8 to 1.2. As with the general polycondensation reaction, the closer the molar ratio is to 1.0, the larger the molecular weight of the polylysine produced.

<polyamidate>

The polyglycolate of one of the polyimine precursors of the present invention can be synthesized by the methods (1) to (3) shown below.

(1) Synthesis by polyaminic acid

Polyammonium ester can be synthesized by esterifying the above polyamic acid.

Specifically, the polyglycine can be esterified with an organic solvent in the presence of an organic solvent. The agent is synthesized at -20 ° C to 150 ° C, preferably at 0 ° C to 50 ° C for 30 minutes to 24 hours, preferably 1 to 4 hours.

The esterifying agent is preferably one which can be easily removed by purification, and is exemplified by N,N-dimethylformamide dimethyl acetal and N,N-dimethylformamide diethyl condensate. Aldehyde, N,N-dimethylformamide dipropyl acetal, N,N-dimethylformamide dinepentylbutyl acetal, N,N-dimethylformamide Third butyl acetal, 1-methyl-3-p-tolyltriazene, 1-ethyl-3-p-tolyltriazene, 1 -propyl-3-p-tolyltriazene, 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride, etc. . The amount of the esterifying agent to be added is 1 mol, more preferably 2 to 6 mol equivalent, based on the repeating unit of the polyamic acid.

The solvent used in the above reaction is preferably N,N-dimethylformamide, N-methyl-2-pyrrolidone or γ-butyrolactone in terms of solubility of the polymer, and one type of these may be used or Mix two or more types. The concentration at the time of the synthesis is less likely to cause precipitation of the polymer, and is preferably from 1 to 30% by mass, more preferably from 5 to 20% by mass, from the viewpoint of easily obtaining a high molecular weight body.

(2) Synthesis by reaction of tetracarboxylic acid diester dichloride with diamine

The polyglycolate can be synthesized from a tetracarboxylic acid diester dichloride and a diamine containing the above specific diamine.

Specifically, the tetracarboxylic acid diester dichloride and the diamine may be reacted in the presence of a base and an organic solvent at -20 ° C to 150 ° C, preferably at 0 ° C to 50 ° C for 30 minutes to 24 hours, preferably. It is synthesized in 1~4 hours.

As the base, pyridine, triethylamine, 4-dimethylaminopyridine or the like can be used, but in order to stably carry out the reaction, pyridine is preferred. The amount of the base to be added is an amount which is easily removed, and from the viewpoint of easily obtaining a high molecular weight body, it is preferably from 2 to 4 moles per mole of the tetracarboxylic acid diester dichloride.

The solvent to be used in the above-mentioned reaction is preferably N-methyl-2-pyrrolidone or γ-butyrolactone in terms of the solubility of the monomer and the polymer. These may be used alone or in combination of two or more. The polymer concentration at the time of synthesis is less likely to cause precipitation of the polymer, and is preferably from 1 to 30% by mass, more preferably from 5 to 20% by mass, from the viewpoint of easily obtaining a high molecular weight body.

Further, in order to prevent hydrolysis of the tetracarboxylic acid diester dichloride, the solvent used in the synthesis of the polyglycolate is preferably dehydrated as much as possible, and the reaction is preferably carried out in a nitrogen atmosphere to prevent incorporation of outside air.

(3) Synthesis of the above polylysine by tetracarboxylic acid diester and diamine

The polyperurethane can be synthesized by polycondensing a tetracarboxylic acid diester with a diamine containing the above specific diamine.

Specifically, the tetracarboxylic acid diester and the diamine can be reacted in the presence of a condensing agent, a base and an organic solvent at 0 ° C to 150 ° C, preferably at 0 ° C to 100 ° C for 30 minutes to 24 hours, preferably 3~. Synthesized in 15 hours.

As the condensing agent, triphenyl phosphite, dicyclohexylcarbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, N, N' can be used. -carbonyldiimidazole, dimethoxy-1,3,5-triazinylmethylmorpholinium, O-(benzotriazol-1-yl)-N,N,N',N'-tetra Urea urea tetrafluoroborate, O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium Fluorated phosphite, diphenyl (2,3-dihydro-2-thio-3-benzoxazolyl)sulfonate, and the like. The amount of the condensing agent added is preferably from 2 to 3 moles per mole of the tetracarboxylic acid diester.

As the base, a tertiary amine such as pyridine or triethylamine can be used. The amount of the base to be added is an amount which is easily removed, and from the viewpoint of easily obtaining a high molecular weight body, it is preferably 2 to 4 times moles relative to the diamine component.

Further, in the above reaction, the reaction is efficiently carried out by adding a Lewis acid as an additive. The Lewis acid is preferably a lithium halide such as lithium chloride or lithium bromide. The amount of the Lewis acid added is preferably from 0 to 1.0 times the molar amount of the diamine component.

In the method for synthesizing the above three polyglycolates, in order to obtain a high molecular weight polyphthalate, the synthesis method of the above (1) or (2) is preferred.

The solution of the polyphthalate obtained as described above can be precipitated by injecting into a weak solvent while stirring well. The precipitated powder is washed several times, washed with a weak solvent, and dried at room temperature or under heating to obtain a purified polyphthalate powder. The weak solvent is not particularly limited and is exemplified by water, methanol, ethanol, hexane, butyl cellosolve, acetone, toluene, and the like.

The polyamine has a weight average molecular weight of preferably from 5,000 to 300,000, more preferably from 10,000 to 200,000. Further, the number average molecular weight is preferably from 2,500 to 150,000, more preferably from 5,000 to 100,000.

(polyimine)

The polymer of the present invention may also be composed of a polyimine which is ruthenium imidized with the above polyimide precursor. In the polyimine of the present invention, a proline group The dehydration ring closure ratio (醯 imidization ratio) is not necessarily 100% and can be arbitrarily adjusted depending on the purpose or purpose.

When the polyimine of the present invention is obtained, the method of imidating the polyimine precursor ruthenium is exemplified by direct heating of a solution of a polyamidene precursor such as polyaminic acid, which is a thermochemical imidization. The catalyst oxime added to the solution of the polyimide precursor is imidized.

The temperature of the polyamidene precursor such as polylysine in the solution is imidized in a solution at a temperature of 100 to 400 ° C, preferably 120 to 250 ° C, and preferably formed by the imidization reaction. The method of removing water outside the system.

The ruthenium imidization of a polyimide precursor such as polyaminic acid can add a basic catalyst and an acid anhydride to a solution of polyamic acid at -20 to 250 ° C, preferably 0 to 0. This was carried out by stirring at 180 °C.

The amount of the alkaline catalyst is 0.5 to 30 moles of the prolyl group, preferably 2 to 20 moles, and the amount of the anhydride is 1 to 50 moles of the amidate group, preferably 3~. 30 moles.

The basic catalyst may, for example, be pyridine, triethylamine, trimethylamine, tributylamine or trioctylamine. Among them, pyridine is preferred because it has a suitable basicity for the reaction.

The acid anhydride may, for example, be acetic anhydride, trimellitic anhydride or pyromellitic anhydride. When acetic anhydride is used, purification after completion of the reaction is preferred, which is preferred.

The imidization ratio of the imidization by the catalyst oxime can be controlled by adjusting the amount of the catalyst, the reaction temperature, and the reaction time.

When the resulting polyimine is recovered from the reaction solution, the reaction solution is preferably poured into a weak solvent to precipitate. The weak solvent used in the precipitation may, for example, be methanol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, water or the like.

The polymer precipitated by pouring into a weak solvent is recovered by filtration, and dried at normal temperature or under heat at normal pressure or reduced pressure. Further, when the precipitate-recovered polymer is redissolved in an organic solvent, and the reprecipitation recovery operation is repeated 2 to 10 times, impurities in the polymer can be reduced. The weak solvent at this time is, for example, an alcohol, a ketone, a hydrocarbon or the like. When three or more kinds of weak solvents selected from the above are used, the purification efficiency can be further improved, which is preferable.

The molecular weight of the polyimine precursor and the polyimine contained in the liquid crystal alignment agent of the present invention is considered by using the strength of the coating film obtained therefrom, the workability at the time of formation of the coating film, and the uniformity of the coating film. The weight average molecular weight measured by the GPC (gel permeation chromatography) method is preferably from 5,000 to 1,000,000, more preferably from 10,000 to 150,000.

<Liquid alignment agent>

The liquid crystal alignment agent of the present invention is a solution for forming a coating liquid for a liquid crystal alignment film and dissolving a polymer component for forming a polymer film in a solvent. Here, the polymer component contains at least one of the above-described polymers of the present invention.

The content of the polymer component is preferably from 1 to 20% by mass, more preferably from 3 to 15% by mass, most preferably from 3 to 10% by mass, based on the liquid crystal alignment agent.

In the present invention, all of the polymer components may be the above The polymer of the present invention may contain other polymers within the range not impairing the effects of the present invention. When the polymer component contains another polymer, the content thereof is preferably 0.05 to 4 parts by mass, more preferably 0.1 to 3 parts by mass, per part by mass of the polymer of the present invention.

The above other polymer is exemplified by, for example, a polyamine compound obtained by using a diamine compound other than the above specific diamine compound, a polyaminic acid obtained by reacting a tetracarboxylic dianhydride component, or a polyamidimide obtained by imidating a polyamic acid. Wait.

The solvent used in the liquid crystal alignment agent of the present invention is preferably an organic solvent in which a polymer component is dissolved, and specific examples thereof are as follows.

The organic solvent is exemplified by N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 2-pyrrolidone, N- Ethylpyrrolidone, N-vinylpyrrolidone, dimethyl hydrazine, tetramethylurea, pyridine, dimethyl hydrazine, hexamethylarylene, γ-butyrolactone, 1,3-dimethyl-imidazole Ketone, ethyl amyl ketone, methyl decyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, cyclohexanone, ethyl carbonate, propyl carbonate, digan Alcohol dimethyl ether, 4-hydroxy-4-methyl-2-pentanone, and the like. These may be used singly or in combination.

The liquid crystal alignment agent of the present invention may have a component other than the above polymer component. Examples thereof include a solvent or a compound which improves uniformity of film thickness or surface smoothness when a liquid crystal alignment agent is applied, a compound which improves adhesion between a liquid crystal alignment film and a substrate, and the like.

The solvent which improves the uniformity of the film thickness or the surface smoothness is a weak solvent which is small in solubility in the polymer component in the liquid crystal alignment treatment agent. Specific examples of the weak solvent are listed below.

For example, isopropanol, methoxymethylpentanol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, butyl card Alcohol, ethyl carbitol, ethyl carbitol acetate, ethylene glycol, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol, propylene glycol Monoacetate, propylene glycol monomethyl ether, propylene glycol tert-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol, diethylene glycol monoacetate, 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, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexane, propyl ether, dihexyl ether, 1-hexanol, n-hexane, n-pentane, n-octyl Alkane, diethyl ether, lactic acid Ester, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, 3-ethoxy Methyl ethyl propyl propionate, ethyl 3-methoxypropionate, 3-ethoxypropionic acid, 3-methoxypropionic acid, propyl 3-methoxypropionate, 3-methoxypropane Butyl acrylate, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-butoxy-2-propanol, 1-phenoxy-2-propanol, propylene glycol Acetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether-2-acetate, dipropylene glycol, 2-(2-ethoxyl) A solvent having a low surface tension such as propyloxy)propanol, methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate or isoamyl lactate.

These weak solvents may be used singly or in combination of plural kinds. When a weak solvent as described above is used, the weak solvent is preferably from 5 to 80% by mass, more preferably from 20 to 60% by mass, based on the total amount of the solvent contained in the liquid crystal alignment agent.

The compound which improves the film thickness uniformity or the surface smoothness at the time of apply|coating a liquid-crystal aligning agent is a fluorine-type surfactant, a polysiloxane surfactant, and a nonionic surfactant.

More specifically, for example, EF TOP (registered trademark) EF301, EF303, EF352 (above, manufactured by Tokemu Products Co., Ltd.), MAGAFAC (registered trademark) F171, F173, R-30 (above, manufactured by Dainippon Ink Co., Ltd.), FLORARD FC430, FC431 (above is Sumitomo 3M), Asahi Guard (registered trademark) AG710 (above is manufactured by Asahi Glass Co., Ltd.), SURFLON (registered trademark) S-382, SC101, SC102, SC103, SC104, SC105, SC106 (above) It is manufactured by AGC Semi Chemical Co., Ltd.). The use ratio of the surfactant is preferably 0.01 to 2 parts by mass, more preferably 0.01 to 1 part by mass, per 100 parts by mass of the polymer component contained in the liquid crystal alignment agent.

Specific examples of the compound which improves the adhesion between the liquid crystal alignment film and the substrate are the following compounds containing a functional decane or a compound containing an epoxy group.

For example, 3-aminopropyltrimethoxydecane, 3-aminopropyltriethoxydecane, 2-aminopropyltrimethoxydecane, 2-aminopropyltriethoxydecane, N- (2-Aminoethyl)-3-aminopropyltrimethoxydecane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxydecane, 3- Ureapropyl propyl trimethoxy decane, 3-ureidopropyl triethoxy decane, N-ethoxycarbonyl-3-aminopropyl trimethoxy decane, N-ethoxycarbonyl-3-amino group Propyltriethoxydecane, N-triethoxydecylpropyltriethylamine, N-trimethoxydecylpropyltriethylamine, 10-trimethoxydecyl-1 ,4,7-triazadecane, 10-triethoxydecyl-1,4,7-triazadecane, 9-trimethoxydecyl-3,6-diazaindole Acid ester, 9-triethoxydecyl-3,6-diazadecyl acetate, N-benzyl-3-aminopropyltrimethoxydecane, N-benzyl-3-amino Propyltriethoxydecane, N-phenyl-3-aminopropyltrimethoxydecane, N-phenyl-3-aminopropyltriethoxydecane, N-bis(oxyethyl) 3-aminopropyltrimethoxydecane, N-bis(oxyethyl)-3-aminopropyltriethoxydecane, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether , propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, Glycerol diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, N,N,N',N '-tetraglycidyl-m-xylylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl Base-4,4'-diaminodiphenylmethane and the like.

When the compound is used to improve the adhesion to the substrate, the amount thereof is preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass, per 100 parts by mass of the polymer component contained in the liquid crystal alignment agent. When the amount used is less than 0.1 part by mass, the effect of improving the adhesion cannot be expected, and when it is more than 30 parts by mass, the liquid crystal alignment property may be deteriorated.

In addition to the above components, the liquid crystal alignment agent of the present invention may be added with a dielectric or a conductive material for changing the electrical properties such as the dielectric constant or the conductivity of the liquid crystal alignment film as long as the effects of the present invention are not impaired. Further, a cross-linking compound or the like which is intended to increase the hardness or density of the film when the liquid crystal alignment film is formed may be added.

<Liquid crystal alignment film and liquid crystal display element>

The liquid crystal alignment agent of the present invention can be applied onto a substrate, dried, and fired to form a coating film, and then subjected to alignment treatment by rubbing treatment or light irradiation, and used as a liquid crystal alignment film. Further, it can be used as a liquid crystal alignment film in an unaligned treatment in a vertical alignment use or the like.

The substrate to be used is not particularly limited as long as it is a substrate having high transparency, and a glass substrate or a plastic substrate such as an acrylic substrate or a polycarbonate substrate can be used. Further, it is preferable from the viewpoint of simplifying the process using a substrate on which an ITO electrode for liquid crystal driving or the like is formed. Further, as the reflective liquid crystal display element, an opaque object such as a single-sided substrate-based wafer may be used. In this case, a material such as aluminum or the like may be used as the electrode.

The coating method of the liquid crystal alignment agent is not particularly limited, but industrially, it is generally carried out by screen printing, lithography, flexographic printing, inkjet printing or the like. As for other coating methods, there are a dipping method, a roll coating method, a slit coating method, and a spin coating method, and these can be used depending on the purpose.

In particular, the liquid crystal alignment agent of the present invention can be prepared by various solvents which are excellent in solubility of the polymer (polymer) component contained therein, and can be suitably used, for example, in an inkjet method or the like.

After the liquid crystal alignment agent is applied onto the substrate, the drying is performed by heating means such as a hot plate at 40 to 130 ° C, preferably 50 to 110 ° C for 20 to 600 seconds, preferably 40 to 300 seconds, to evaporate the solvent. Coating film.

The liquid crystal alignment agent is coated on the substrate and dried, and then fired by heating means, oven, IR oven, etc., at 50 to 300 ° C, preferably 80 to 250 ° C for 5 to 120 minutes, preferably 8 ~60 minutes, the polyimine precursor was polyimidized to form a ruthenium-imided polymer coating film.

When the thickness of the coating film formed after firing is too thick, it is disadvantageous in terms of power consumption of the liquid crystal display element, and if it is too thin, the reliability of the liquid crystal display element may be lowered, so it is preferably 5 to 300 nm, more preferably 10 to 10. 100nm. When the liquid crystal is aligned horizontally or obliquely, the film after the firing is treated by alignment such as rubbing or polarized ultraviolet irradiation.

In the liquid crystal display device of the present invention, a liquid crystal alignment film is formed on a substrate from the liquid crystal alignment agent of the present invention, and a substrate having a liquid crystal alignment film is obtained, and a liquid crystal cell is produced by a known method to obtain a liquid crystal display element.

Examples of the liquid crystal cell formation include a substrate on which a liquid crystal alignment film is formed, and a spacer is disposed on a liquid crystal alignment film of one substrate so that the liquid crystal alignment film surface becomes inside. In combination with another substrate, a liquid crystal is injected under reduced pressure and sealed, or a liquid crystal is dropped on a liquid crystal alignment film surface on which a spacer is dispersed, and the substrate is bonded and sealed. The thickness of the separator at this time is a liquid crystal thickness between the substrates in the liquid crystal display element, and is preferably from 1 to 30 μm, more preferably from 2 to 10 μm.

As described above, the liquid crystal display element produced by forming the liquid crystal alignment film using the liquid crystal alignment agent of the present invention is excellent in reliability, and can be preferably used in a large-screen, high-precision liquid crystal television or the like.

Example

The invention is illustrated in more detail below by way of examples and comparative examples, but the invention is not construed as being limited to the examples.

The abbreviations and structures of the compounds used in the synthesis examples, examples and comparative examples of the present invention are listed below.

(Organic solvents)

DMF: N,N-dimethylformamide

THF: tetrahydrofuran

NMP: N-methyl-2-pyrrolidone

GBL: γ-butyrolactone

BCS: ethylene glycol monobutyl ether

(tetracarboxylic dianhydride)

BDA: 1,2,3,4-butane tetracarboxylic dianhydride

PMDA: pyromellitic dianhydride

CBDA: 1,2,3,4-cyclobutane tetracarboxylic dianhydride

BODA: bicyclo[3.3.0]octane-2,4,6,8-tetracarboxylic dianhydride

(diamine compound)

ODA: 4,4'-oxydiphenylamine

DDM: 4,4'-diaminodiphenylmethane

DA-B: diamine of the following formula DA-B

The method of measuring ¹ H-NMR, molecular weight, and single crystal X-ray structure analysis is shown below.

[ ¹ H-NMR]

Device: Fourier transform type superconducting nuclear magnetic resonance apparatus (FT-NMR) INOVA-400 (manufactured by Varian) 400 MHz

Solvent: deuterated dimethyl sulfoxide (DMSO-d ₆₎ or deuterated chloroform (CDCl ₃₎

Reference material: tetramethyl decane (TMS)

Accumulated times: 8 or 32

[Single crystal X-ray structure analysis]

Device: APEX2 (manufactured by Bruker)

Measuring temperature: 298.0K

X-ray: Cu

[Molecular weight determination]

The molecular weight of the polymer was measured using a room temperature gel permeation chromatography (GPC) apparatus (GPC-101) manufactured by Showa Denko Co., Ltd., and a column (KD-803, KD-805) manufactured by Shodex Co., Ltd., as follows.

Column temperature: 50 ° C

Dissolution: N,N'-dimethylformamide (as an additive, lithium bromide monohydrate (LiBr‧H ₂ O) system 30 mmol/L (liter), phosphoric acid ‧ anhydrous crystal (o-phosphoric acid) 30 mmol / L, tetrahydrofuran (THF) system 10ml / L)

Flow rate: 1.0ml/min

Standard sample for calibration line preparation: TSK standard polyethylene oxide (molecular weights of about 900,000, 150,000, 100,000, and 30,000) manufactured by TOSOH Corporation and polyethylene glycol (molecular weights of about 12,000, 4000, and 1000) manufactured by Polymer Library.

Synthesis of Aromatic Diamine Compound (1N-Boc-4-(3,5-Diaminobenzyloxymethyl)-5-Methylimidazole) (DA-A)

The aromatic diamine compound (DA-A) was synthesized by the three-step route shown below. Further, the aromatic diamine compound (DA-A) corresponds to a specific diamine compound of the above formula (3).

First step: synthesis of 1N-Boc-4-hydroxymethyl-5-methylimidazole (DA-A-1)

4-Hydroxymethyl-5-methylimidazolium hydrochloride (25.4 g, 171 mmol) was suspended in DMF (102 g), and triethylamine (34.6 g, 342 mmol). Next, a solution obtained by dissolving dibutyl succinate (41.1 g, 188 mmol) in DMF (25 g) was added dropwise over 15 minutes. Subsequently, the reaction mixture was stirred for 18 hours, and the disappearance of the starting material was confirmed by HPLC (thin layer chromatography). Next, the precipitated solid was removed by filtration, and the filtrate was concentrated and dried. Toluene (127 g) was added to the obtained oil, and the precipitated white solid was removed by filtration. Subsequently, the filtrate was concentrated and dried to give 1N-Boc-4-hydroxymethyl-5-methylimidazole (DA-A-1) and 3N-Boc-4-hydroxymethyl-5-methylimidazole as a yellow oil. A mixture of (DA-C-1) (yield 36.19 g, yield 100%). The isomer ratio of the two species was found to be 60:40 from ¹ H-NMR.

(DA-A-1) ¹ H-NMR (CDCl ₃ , δ ppm): 8.05 (s, 1H, -N=C(H)-N-), 4.74 (t, J = 5.4 Hz, 1H, OH), 4.56 (d, J = 5.4 Hz, 2H, CH ₂ ), 2.11 (s, 3H, -C=C(N)CH ₃ ), 1.56 (s, 9H, t-Bu).

^{(DA-C-1) 1} H-NMR (CDCl 3, δppm): 8.03 (s, 1H, -N = C (H) -N -), 4.83 (t, J = 5.4Hz, 1H, OH), 4.29 (d, J = 5.4 Hz, 2H, CH ₂ ), 2.36 (s, 3H, -C=C(N)CH ₃ ), 1.55 (s, 9H, t-Bu).

Step 2: Synthesis of 1N-Boc-4-(3,5-dinitrobenzylideneoxymethyl)-5-methylimidazole (DA-A-2)

a mixture of 1N-Boc-4-hydroxymethyl-5-methylimidazole (DA-A-1) and 3N-Boc-4-hydroxymethyl-5-methylimidazole (DA-C-1) (35.8 g, 168.5 mmol) dissolved in DMF (175 g), added triethylamine (40.9 g, 404 mmol), cooled to 3 ° C, and added 3,5-dinitrobenzoguanidine chloride (50.5 g) over 25 minutes , 219 mmol) a solution dissolved in DMF (51 g). Subsequently, the reaction mixture was stirred at 20 ° C for 3 hours, and after HPLC was measured, 3,5-dinitrobenzimid chloride (11.7 g, 50.6 mmol) was further added and stirred for 16 hours due to 5% of the residual amount of the raw materials. It was confirmed by HPLC that the starting material had disappeared. Next, a mixed solution (680 mL) of ethyl acetate/hexane (2/1 (volume ratio)) was added to the reaction liquid, and the organic phase was washed three times with water (220 g). Subsequently, the precipitate was filtered, and the solid was washed twice with ethyl acetate (50 g) and dried to obtain 1N-Boc-4-(3,5-dinitrobenzyloxymethyl)-5-methylimidazole. (DA-A-2) (revenue 27.4 g, yield 40%).

The obtained compound was a single isomer (DA-A-2 (1N-Boc)) from ¹ H-NMR. The structure of the isomer was determined by ¹ H-NMR, ¹³ C-NMR and X-ray crystal structure analysis.

Fig. 1 is an X-ray structural analysis image of a compound (DA-A-2) which is a precursor of a diamine compound used in the examples.

The measurement data of ¹ H-NMR and ¹³ C-NMR of the obtained compound (DA-A-2 (1N-Boc)) and the analysis data of the X-ray crystal structure analysis are shown below.

(DA-A-2) ¹ H-NMR (CDCl ₃ , δ ppm): 9.21 (d, J = 2.0 Hz, 1H, C ₆ H ₃ (NO ₂ ) ₂ ), 9.16 (d, J = 2.0 Hz, 1H) , C ₆ H ₃ (NO ₂ ) ₂ ), 8.07 (s, 1H, -N=C(H)-N-), 5.39 (s, 2H, CH ₂ ), 2.53 (s, 3H, -C=C (N) CH ₃ ), 1.64 (s, 9H, t-Bu).

(DA-A-2) ¹³ C-NMR (CDCl ₃ , δ ppm): 162.5, 148.5, 147.5, 137.4, 133.8, 133.6, 129.6, 128.7, 122.4, 85.9, 70.0, 27.9, 11.0 (each s).

(DA-A-2) X-ray crystal structure analysis data

Construction formula: C ₁₇ H ₁₈ N ₄ O ₈

Crystalline system: monoclinic system (Monoclinic)

Space group: P2 ₁ /c

Lattice number: a=8.5079(5) angb=19.6087(12) ang c=11.3540(8) angstrom β=92.852(4)°

Z value: 4

R/WR: 0.33/0.11

The organic layer filtrate in the synthesis of 1N-Boc-4-(3,5-dinitrobenzylideneoxymethyl)-5-methylimidazole (DA-A-2) in the above second step is concentrated. A mixed solution of ethyl acetate/hexane (volume ratio: 2/1) (889 g) was added to the residue, and water (363 g) was added thereto, and the mixture was stirred for 1 hour, and the obtained solid was filtered. The filtrate was separated, and a mixed solution of ethyl acetate/hexane (2/1) (889 g) and water (363 g) were added to the organic layer and stirred, and the obtained solid was filtered. The filtrate was concentrated, and a mixed solution of ethyl acetate/hexane (1/2) (889 g) was added to the residue, and the mixture was cooled to 0 ° C, and stirred to obtain a precipitate. The solid was washed twice with ethyl acetate (50 g) and dried to give 3N-Boc-4-(3,5-dinitrobenzyloxymethyl)-5-methylimidazole (DA-C- 2) (received 4.3 g, yield 2%).

The obtained compound was a single isomer (DA-C-2 (3N-Boc)) by ¹ H-NMR. The structure of the isomer was determined by ¹ H-NMR and ¹³ C-NMR.

The measurement data of ¹ H-NMR and ¹³ C-NMR of the obtained compound (DA-C-2 (3N-Boc)) are shown below.

(DA-C-2) ¹ H-NMR (CDCl ₃ , δ ppm): 9.22 (t, J = 2.4 Hz, 1H, C ₆ H ₃ (NO ₂ ) ₂ ), 9.13 (d, J = 2.4 Hz, 2H , C ₆ H ₃ (NO ₂ ) ₂ ), 8.11 (s, 1H, -N=C(H)-N-), 5.64 (s, 2H, CH ₂ ), 2.34 (s, 3H, -C=C (N) CH ₃ ), 1.64 (s, 9H, t-Bu).

(DA-C-2) ¹³ C-NMR (CDCl ₃ , δ ppm) 162.2, 148.6, 147.0, 142.5, 138.7, 133.8, 129.5, 122.4, 120.2, 86.1, 57.5, 27.9, 12.7 (each s).

Step 3: Synthesis of aromatic diamine compound (DA-A)

Making 1N-Boc-4-(3,5-dinitrobenzylideneoxymethyl)- 5-methylimidazole (DA-A-2) (21.9 g, 53.8 mmol) was suspended in methanol (175 g), and after replacing the inside with nitrogen, 5% by mass of palladium-carbon (2.18 g, 55 mass% of water was added) The material was replaced with hydrogen and reacted at room temperature for 8 days. Subsequently, the disappearance of the starting material was confirmed by HPLC (High Speed Liquid Chromatography), and palladium-carbon was removed by filtration. Next, the solvent methanol (100 g) was distilled off under reduced pressure at 40 ° C and 120 mmHg, followed by the addition of 2-propanol (103 g). The solvent methanol and 2-propanol (150 g) were distilled off under reduced pressure at 40 ° C and 120 mmHg, followed by 2-propanol (50 g). Subsequently, it was allowed to stand under ice cooling for 1 hour to precipitate a diamine (DA-A), which was filtered and dried to give an aromatic diamine compound (DA-A) (12.9 g, yield 69%).

¹ H-NMR (CDCl ₃ , δ ppm): 7.98 (s, 1H, -N=C(H)-N-), 6.68 (d, J = 2.0 Hz, 1H, C ₆ H ₃ (NH ₂ ) ₂ ) , 6.06 (t, 2H, C ₆ H ₃ (NH ₂ ) ₂ ), 5.14 (s, 2H, CH ₂ ), 2.42 (s, 3H, -C=C(N)CH ₃ ), 1.55 (s, 9H) , t-Bu).

¹³ C-NMR (CDCl ₃ , δ ppm): 166.7, 147.5, 147.4, 136.9, 134.8, 131.6, 127.7, 106.7, 105.5, 85.4, 58.9, 27.7, 10.8 (each s).

3N-Boc-4-(3,5-dinitrobenzylideneoxymethyl)-5-methylimidazole (DA-C-2) (2.00 g, 4.92 mmol) was suspended in methanol (16 g) After replacing the inside with nitrogen, 5% by mass of palladium-carbon (0.201 g, 57% by mass of hydrate) was added, and the inside was replaced with hydrogen, and reacted at room temperature for 3 days. Subsequently, after confirming the disappearance of the starting material by HPLC, the palladium-carbon was removed by filtration, and the solvent was concentrated to dryness to obtain an aromatic diamine compound (DA-C) (1.43 g, yield: 84%).

¹ H-NMR (CDCl ₃ , δ ppm): 8.11 (s, 1H, -N=C(H)-N-), 6.73 (d, J = 2.0 Hz, 1H, C ₆ H ₃ (NH ₂ ) ₂ ) , 6.16 (t, J = 2.0 Hz, 2H, C ₆ H ₃ (NH ₂ ) ₂ ), 5.40 (s, 2H, CH ₂ ), 2.28 (s, 3H, -C=C(N)CH ₃ ), 1.57 (s, 9H, t-Bu).

¹³ C-NMR (CDCl ₃ , δ ppm): 166.6, 147.5, 147.3, 141.6, 138.5, 131.8, 121.1, 106.8, 105.7, 85.8, 56.0, 27.8, 12.7 (each s).

[Modulation of Liquid Crystal Aligning Agent] (Example 1)

0.47 g (3.00 mmol) of 3,5-diaminobenzoic acid was placed in a 50 mL four-necked flask equipped with a stirring device and a nitrogen introduction tube, and 3.75 g of NMP was added thereto, and the mixture was stirred and dissolved by blowing nitrogen gas. Next, 1.039 g (3.00 mmol) of DA-A, 0.801 g (4.00 mmol) of ODA, and 1.87 g of GBL were added, and the mixture was stirred and dissolved while blowing nitrogen gas. While stirring the diamine solution, 0.594 g (3.00 mmol) of BDA and 3.00 g of GBL were added, and the mixture was stirred under water cooling for 2 hours. Next, 1.505 g (6.9 mmol) of PMDA and 10.12 g of GBL were added, and the mixture was stirred under water cooling for 24 hours. The obtained polyaminic acid solution has a viscosity of 3010 mPa at a temperature of 25.0 ° C. s. Further, the molecular weight of the polyamic acid was Mn = 17015 and Mw = 42,151. Next, 4.40 g of a mixed solution having a NMP/GBL ratio of 2/8 (volume ratio, the same below) was added to the solution to be diluted to 0.3% by mass of 3-glycidoxypropylmethyldiethoxydecane. Solution to obtain a polyaminic acid solution.

5.63 g of the obtained polyaminic acid solution, 0.57 g of NMP, 9.81 g of GBL, and 4.0 g of BCS were placed in a 50 mL sample vial to which a stir bar was added to obtain a liquid crystal alignment agent (A-1). The liquid crystal alignment agent was not observed to be turbid or precipitated, and was confirmed to be a homogeneous solution.

(Example 2)

Placed in a 50 mL four-necked flask with a stirring device and a nitrogen inlet tube 2.355 g (6.80 mmol) of DA-A and 2.02 g (10.20 mmol) of DDM were added, and 6.94 g of NMP and 3.47 g of GBL were added, and the mixture was stirred and dissolved while blowing nitrogen gas. While stirring the diamine solution, 1.634 g (8.33 mmol) of CBDA and 5.55 g of GBL were added, and the mixture was stirred under water cooling for 2 hours. Next, 2.127 g (8.50 mmol) of BODA and 18.7 g of GBL were added, and the mixture was stirred under water cooling for 24 hours. The viscosity of the obtained polyaminic acid solution at a temperature of 25.0 ° C is 99.3 mPa. s. Further, the molecular weight of the poly-proline was Mn = 5245 and Mw = 9647. Next, 8.14 g of a mixed solution of NMP/GBL ratio of 2/8 was added to the solution to prepare a 0.3% by mass solution of 3-glycidoxypropylmethyldiethoxydecane to obtain polylysine. Solution.

5.63 g of the obtained polyaminic acid solution, 0.57 g of NMP, 9.81 g of GBL, and 4.0 g of BCS were placed in a 50 mL sample vial to which a stir bar was added to obtain a liquid crystal alignment agent (A-2). The liquid crystal alignment agent was not observed to be turbid or precipitated, and was confirmed to be a homogeneous solution.

(Comparative Example 1)

0.93 g (6.00 mmol) of 3,5-diaminobenzoic acid was placed in a 50 mL four-necked flask equipped with a stirring device and a nitrogen introduction tube, and 6.67 g of NMP was added thereto, and the mixture was stirred and dissolved by blowing nitrogen gas. Next, 2.803 g (14.0 mmol) of ODA and 3.34 g of GBL were added, and the mixture was dissolved while stirring with nitrogen gas. While stirring the diamine solution, 1.189 g (6.00 mmol) of BDA and 4.67 g of GBL were added, and the mixture was stirred under water cooling for 2 hours. Next, 2.923 g (13.4 mmol) of PMDA and 18.7 g were added. The GBL was stirred under water cooling for 24 hours. The viscosity of the obtained polyaminic acid solution at a temperature of 25.0 ° C is 3701 mPa. s. Further, the molecular weight of the polyproline was Mn = 11194 and Mw = 26713. Next, 7.83 g of a mixed solution of NMP/GBL ratio of 2/8 was added to the solution to a 0.3% by mass solution of 3-glycidoxypropylmethyldiethoxydecane to obtain polylysine. Solution.

5.63 g of the obtained polyaminic acid solution, 0.57 g of NMP, 9.81 g of GBL, and 4.0 g of BCS were added to a 50 mL sample vial to which a stir bar was added to obtain a liquid crystal alignment agent (B-1). The liquid crystal alignment agent was not observed to be turbid or precipitated, and was confirmed to be a homogeneous solution.

(Comparative Example 2)

0.47 g (3.00 mmol) of 3,5-diaminobenzoic acid was placed in a 50 mL four-necked flask equipped with a stirring device and a nitrogen introduction tube, and 3.53 g of NMP was added thereto, and the mixture was stirred and dissolved by blowing nitrogen gas. Next, 0.778 g (3.00 mmol) of DA-B, 0.801 g (4.00 mmol) of ODA, and 1.76 g of GBL were added, and the mixture was stirred and dissolved by blowing nitrogen gas. While stirring the diamine solution, 0.594 g (3.00 mmol) of BDA and 2.82 g of GBL were added, and the mixture was stirred under water cooling for 2 hours. Next, 1.505 g (6.9 mmol) of PMDA and 9.52 g of GBL were added, and the mixture was stirred under water cooling for 24 hours. However, the polymer was precipitated during the reaction, and the liquid crystal alignment agent could not be prepared.

(Comparative Example 3)

3.965 g (20.0 mmol) of DDM was placed in a 50 mL four-necked flask equipped with a stirring device and a nitrogen introduction tube, and 7.15 g of NMP and 3.58 g of GBL were added, and the mixture was dissolved while stirring with nitrogen gas. While stirring the diamine solution, 1.922 g (9.80 mmol) of CBDA and 5.72 g of GBL were added, and the mixture was stirred under water cooling for 2 hours. Next, 2.502 g (10.00 mmol) of BODA and 12.2 g of GBL were added, and the mixture was stirred under water cooling for 24 hours. The obtained polyaminic acid solution has a viscosity of 1534 mPa at a temperature of 25.0 ° C. s. Further, the molecular weight of the polyamic acid was Mn = 13910 and Mw = 41256. Next, 8.39 g of a mixed solution of NMP/GBL ratio of 2/8 was added to the solution to a 0.3% by mass solution of 3-glycidoxypropylmethyldiethoxysilane to obtain polylysine. Solution.

5.63 g of the obtained polyaminic acid solution, 0.57 g of NMP, 9.81 g of GBL, and 4.0 g of BCS were added to a 50 mL sample vial to which a stir bar was added to obtain a liquid crystal alignment agent (B-2). The liquid crystal alignment agent was not observed to be turbid or precipitated, and was confirmed to be a homogeneous solution.

<Comparative Example 4>

1.76 g (6.80 mmol) of DA-B and 2.02 g (10.20 mmol) of DDM were placed in a 50 mL four-necked flask equipped with a stirring device and a nitrogen introduction tube, and 6.43 g of NMP and 3.22 g of GBL were added while blowing. The nitrogen gas was stirred to dissolve it. While stirring the diamine solution, 1.634 g (8.33 mmol) of CBDA and 5.15 g of GBL were added, and the mixture was stirred under water cooling for 2 hours. Next, 2.127 g (8.50 mmol) of BODA and 17.3 g of GBL were added, and the mixture was stirred under water cooling for 24 hours. However, caused during the reaction When the polymer was precipitated, the polyaminic acid solution could not be obtained, and the liquid crystal alignment agent could not be prepared.

[Measurement of volume resistivity] (Example 3)

Using the liquid crystal alignment agent obtained in the examples and the comparative examples, the mixture was filtered through a 0.2 μm filter and then spin-coated on a glass substrate with an ITO transparent electrode. Subsequently, it was dried on a hot plate at 80 ° C for 2 minutes and baked at 230 ° C for 20 minutes to form a coating film having a film thickness of 100 nm. Alvaporating aluminum on the surface of the coating film through a mask to form 1.0 mm The upper electrode (aluminum electrode) was used as a sample for volume resistivity measurement. A DC voltage of 1 V was applied between the ITO electrode and the aluminum electrode of the sample, and the current value after 180 seconds from the application of the voltage was measured, and the volume resistivity was calculated from the value and the electrode area and the film thickness.

The measurement results are shown in Table 1.

[Production of IPS mode liquid crystal cells] (Example 4)

The liquid crystal alignment agent obtained in the examples and the comparative examples was filtered through a 0.2 μm filter, and then spin-coated to be formed so as to have a comb-shaped tooth shape and separate and bite each other. One of the pair of ITO electrodes (electrode width: 10 μm, electrode spacing: 10 μm, electrode height: 50 nm) was switched on a glass substrate (In Plain Switching: hereinafter referred to as IPS) as an electrode. Subsequently, it was dried on a hot plate at 80 ° C for 2 minutes and baked at 230 ° C for 20 minutes to obtain a film thickness. 100 nm coating film. The polyimide film was rubbed with a crepe cloth (roller diameter: 120 mm, number of revolutions of 1000 rpm, moving speed of 20 mm/sec, press-in amount of 0.3 mm, and angle of 15 degrees with respect to the IPS comb-type tooth electrode). Subsequently, ultrasonic cleaning was performed for 1 minute in pure water, and dried at 80 ° C for 10 minutes to obtain a substrate with a liquid crystal alignment film. Further, a coating film was formed in the same manner as the glass substrate having a columnar spacer having a height of 4 μm as an electrode on the opposite substrate, and the alignment treatment was also applied.

As described above, the sealant is printed on one of the two substrates, and the sealant is bonded so that the rubbing directions of the two substrates are 180 degrees in the opposite direction, and the sealant is hardened to form a hollow cell. Liquid crystal MLC-2041 (manufactured by Merck Co., Ltd.) was injected into the hollow cell by a vacuum injection method, and the injection port was sealed to obtain an IPS mode liquid crystal cell.

[Measurement of voltage holding ratio] (Example 5)

The measurement was carried out by using the liquid crystal cell (IPS mode liquid crystal cell) produced in Example 4 using a 6254 liquid crystal physical property evaluation device manufactured by Dongyang Technology Co., Ltd. A voltage of 4 V was applied to each liquid crystal cell at a temperature of 60 ° C for 60 μsec, and the voltage holding ratio after 1667 m seconds after the application was released ((voltage after 1667 m seconds after the application was released) / voltage just applied) × 100% ).

The measurement results are shown in Table 1.

[Evaluation of residual image from residual charge due to DC voltage] (Example 6)

Each liquid crystal cell (IPS mode liquid crystal cell) produced in Example 4 was placed on a light source, and VT characteristics (voltage-transmittance characteristics) were measured, and then an alternating current voltage of 60% transmittance/60 Hz rectangular wave was applied for 10 minutes. . Next, a DC of 1 V was superimposed on a rectangular wave of 23.0% ac/60 Hz and driven for 30 minutes. Subsequently, the DC voltage was cut off, and then driven by a 23% AC voltage/60 Hz rectangular wave for 30 seconds, and then the transmittance of the liquid crystal cell was measured. The difference (ΔT (%)) between the obtained transmittance and the initial transmittance (23.0%) was evaluated as a residual image derived from the residual electric charge due to the DC voltage in the liquid crystal display element.

The summary of the evaluation results is shown in Table 1.

From the results of Table 1, it is understood that the polymer of the examples of the present invention is excellent in solubility. Further, the liquid crystal alignment film obtained from the liquid crystal alignment agent of the example had a lower volume resistivity than the liquid crystal alignment film obtained from the liquid crystal alignment agent of the comparative example. That is, the compounds of the examples can form solubility The polymer is excellent, and the liquid crystal alignment agent is easily prepared, and a liquid crystal alignment film having a low volume resistivity can be formed.

Further, it is understood that the liquid crystal cell having the liquid crystal alignment film of the example has excellent afterimage characteristics and a high voltage holding ratio, and has performance required for a liquid crystal display element.

[Industrial Applicability]

By using a liquid crystal alignment agent containing the polymer of the present invention, a liquid crystal alignment film having excellent electrical characteristics and improved display defects such as afterimages can be obtained, and the liquid crystal alignment film can be utilized for a large-sized liquid crystal television having high display quality in the past. Or in the liquid crystal display elements such as smart phones or tablet computers that are rapidly demanding display quality improvement in recent years.

The entire contents of the specification, the scope of the application, the drawings and the abstract of the Japanese Patent Application No. 2012-188874, filed on Aug.

Claims (13)

A liquid crystal alignment agent characterized by comprising at least one polymer selected from the group consisting of a polyimide precursor and a polyimine obtained by subjecting the polyimide precursor to ruthenium imidization. The polyimine precursor is obtained by using one or more kinds of diamine components selected from the group consisting of diamine compounds represented by the following formulas (1) and (2). (Boc represents a third butoxycarbonyl group, R ¹ is a single bond, -CH ₂ - or -CH ₂ CH ₂ -, and R ² is -O-, -COO-, -OCO-, -NHCO-, -CONH- , -NH-, -N(CH ₃ )-, -CON(CH ₃ )-, -N(CH ₃ )CO- or -N(COMe)- (here, Me represents a methyl group), R ³ is a single a bond or a divalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, wherein any hydrogen atom of the aliphatic hydrocarbon group may be substituted with a carboxyl group or an ester group, and R ⁴ is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and R ⁵ is hydrogen. Atom or an alkyl group having 1 to 20 carbon atoms), ^{(Boc, R 1, R 2} , Boc R 3, R 4 and R ⁵ in the formula (1) ^{of, R 1, R 2, R} 3, and R is defined the same as R ⁴ of ^5). The liquid crystal alignment agent of claim 1, wherein the polyimine precursor is obtained by combining a diamine represented by the formula (1) and the formula (2) Polylysine obtained by reacting one or more kinds of diamine components selected from the group consisting of tetracarboxylic dianhydride. The liquid crystal alignment agent of claim 1 or 2, wherein the diamine compound is one or more selected from the group consisting of the following formulas (3) and (4), (Boc represents a third butoxycarbonyl group, and Me represents a methyl group). The liquid crystal alignment agent of claim 1 or 2, wherein the content of the polymer is from 1 to 20% by mass in the liquid crystal alignment agent. A liquid crystal alignment film which is obtained by coating and drying a liquid crystal alignment agent according to any one of claims 1 to 4. The liquid crystal alignment film of claim 5, wherein the sintering temperature is 50 to 300 °C. The liquid crystal alignment film of claim 5 or 6, wherein the film thickness after sintering is 5 to 300 nm. A liquid crystal display element having the liquid crystal alignment film according to any one of claims 5 to 7. A diamine compound represented by any one of the following formulas (1) and (2), (Boc represents a third butoxycarbonyl group, R ¹ is a single bond, -CH ₂ - or -CH ₂ CH ₂ -, and R ² is -O-, -COO-, -OCO-, -NHCO-, -CONH- , -NH-, -N(CH ₃ )-, -CON(CH ₃ )-, -N(CH ₃ )CO- or -N(COMe)- (here, Me represents a methyl group), R ³ is a single a bond or a divalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, wherein any hydrogen atom of the aliphatic hydrocarbon group may be substituted with a carboxyl group or an ester group, and R ⁴ is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and R ⁵ is hydrogen. Atom or an alkyl group having 1 to 20 carbon atoms), ^{(Boc, R 1, R 2} , Boc R 3, R 4 and R ⁵ in the formula (1) ^{of, R 1, R 2, R} 3, and R is defined the same as R ⁴ of ^5). The amine compound of claim 9, wherein R ⁵ in the formula (1) and the formula (2) is hydrogen. The amine compound of claim 9 or 10, wherein R ⁴ in the formula (1) and the formula (2) is a methyl group. A diamine compound represented by any one of the following formulas (3) and (4), (Boc represents a third butoxycarbonyl group, and Me represents a methyl group). A polymer obtained by using one or more selected from the group consisting of diamine compounds according to any one of claims 9 to 12.