TWI428370B - Liquid crystal aligning agent and liquid crystal display element - Google Patents

Description

Liquid crystal alignment agent and liquid crystal display element

The present invention relates to a liquid crystal alignment agent and a liquid crystal display element. More specifically, it relates to a liquid crystal alignment agent capable of forming a liquid crystal alignment film excellent in voltage holding ratio and afterimage performance, and a liquid crystal display element excellent in afterimage performance.

At present, as a liquid crystal display element, a TN type liquid crystal display element having a so-called TN type (twisted nematic) liquid crystal cell is widely known, and liquid crystal is formed on a surface of a substrate on which a transparent conductive film such as an ITO (indium-tin oxide) film is provided. An alignment film is used as a substrate for a liquid crystal display element, and two substrates are arranged to face each other, and a nematic liquid crystal layer having positive dielectric anisotropy is formed in the gap to form a unit cell of a sandwich structure, and a long axis of liquid crystal molecules The substrate is continuously twisted 90 degrees from one substrate to another. In addition, an STN (Super Twisted Nematic) liquid crystal display element capable of achieving higher contrast than a TN type liquid crystal display element has been developed. The alignment of the liquid crystal molecules in the above-described TN type and STN type liquid crystal display elements is usually controlled by a liquid crystal alignment film which has been subjected to a rubbing treatment.

In contrast, an MVA (Multi-Domain Vertical Alignment) type liquid crystal display element having improved viewing angle performance by providing protrusions on a transparent conductive film and controlling alignment of liquid crystal molecules is also developed (see Patent Document 1 and Non-Patent Document 1). Vertical alignment of an EVA (Reinforced Vertical Alignment) type liquid crystal display element (see Non-Patent Document 2) and a vertical alignment type liquid crystal display element (see Non-Patent Document 3) using a photo-alignment method, which are controlled by a special electrode structure Type liquid crystal display element. These vertical alignment type liquid crystal display elements are excellent in viewing angle performance, contrast, and the like, and are not required to be subjected to a rubbing treatment or the like in the process of forming a liquid crystal alignment film, and are therefore excellent in a manufacturing process. However, compared with the above-described TN type and STN type liquid crystal display elements, the performance is not very good, and in particular, it is required to improve the properties of vertical alignment and residual image performance of a liquid crystal display element.

In order to solve the above problems, attempts have been made to focus on the relationship between voltage holding ratio and afterimage performance, and a polyamidimide synthesized from a diamine compound having an allyl group or a quinone imidized polymer thereof is used for a liquid crystal alignment film to The voltage holding ratio is increased, and thereby the residual performance is improved (see Patent Document 2), but even with this technique, the improvement in afterimage performance is still not good enough.

In addition, attempts have been made to improve the voltage by using a polyphthalic acid synthesized from a tetracarboxylic dianhydride containing 1,2,3,4-cyclobutanetetracarboxylic dianhydride and pyromellitic dianhydride as a liquid crystal alignment agent. The retention ratio, residual charge, and afterimage performance (see Patent Documents 3 to 6), but when these techniques are employed, there is a problem that a sufficient voltage holding ratio cannot be obtained.

[Patent Document 1] Japanese Patent Laid-Open No. Hei 11-258605

[Patent Document 2] International Publication No. WO2005/052028

[Patent Document 3] Japanese Patent Application No. 2001-206168

[Patent Document 4] Japanese Patent Publication No. 2001-510497

[Patent Document 5] Japanese Patent Laid-Open Publication No. 2001-296525

[Patent Document 6] Japanese Patent Laid-Open No. Hei 10-197875

[Patent Document 7] Japanese Patent Laid-Open No. Hei 6-222366

[Patent Document 8] Japanese Patent Laid-Open No. Hei 6-281939

[Patent Document 9] Japanese Patent Laid-Open No. Hei 5-170044

[Non-Patent Document 1] "Liquid Crystal", Vol. 3, No. 2, p117 (1999).

[Non-Patent Document 2] "Liquid Crystal", Vol. 3, No. 4, p272 (1999).

[Non-Patent Document 3] "Jpn Appl. phys.", Vol. 36, p428 (1997)

The present invention has been made in view of the above circumstances, and an object thereof is to provide a liquid crystal alignment property which is not only applicable to a TN type and an STN type but also to a vertical alignment type liquid crystal display element, and which exhibits good liquid crystal alignment and voltage retention. A liquid crystal alignment agent of a liquid crystal alignment film excellent in rate and afterimage performance, and a liquid crystal display element excellent in residual performance.

Other objects and advantages of the present invention will be apparent from the following description.

According to the present invention, the above object of the present invention, first, is achieved by a liquid crystal alignment agent comprising at least one polymer selected from the group consisting of polylysine and a ruthenium iodide polymer thereof. The amine acid is obtained by reacting a tetracarboxylic dianhydride containing 1,2,3,4-cyclobutanetetracarboxylic dianhydride with respect to all tetracarboxylic dianhydrides, and a diamine. ～10 mol% of pyromellitic dianhydride, which contains a compound represented by the following formula (1).

The above object of the present invention, and secondly, is achieved by a liquid crystal display element having a liquid crystal alignment film formed of the above liquid crystal alignment agent.

<polylysine>

The polyphthalic acid contained in the liquid crystal alignment agent of the present invention can be made to contain 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 1 to 10 mol% based on the total tetracarboxylic dianhydride. The tetracarboxylic dianhydride of pyromellitic dianhydride is synthesized by reacting with a diamine containing the compound represented by the above formula (1).

[tetracarboxylic dianhydride]

The tetracarboxylic dianhydride used in the synthesis of the polyamic acid contains at least 1,2,3,4-cyclobutanetetracarboxylic dianhydride and pyromellitic dianhydride. In the synthesis of the above polyamic acid, a tetracarboxylic dianhydride other than 1,2,3,4-cyclobutanetetracarboxylic dianhydride and pyromellitic dianhydride may be used in combination.

Examples of these other tetracarboxylic dianhydrides include butane tetracarboxylic dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutane tetracarboxylic dianhydride, and 1,3-two. Methyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dichloro-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3, 4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexane Alkane tetracarboxylic dianhydride, 3,3',4,4'-dicyclohexyltetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 3,5,6-tricarboxyl Norbornane-2-acetic acid dianhydride, 2,3,4,5-tetrahydrofuran tetracarboxylic dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-di Oxo-3-furanyl)-naphthalene [1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-5-methyl-5-( Tetrahydro-2,5-dioxo-3-furanyl)-naphthalene[1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro- 5-ethyl-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphthalene[1,2-c]-furan-1,3-dione, 1,3,3a,4 ,5,9b-hexahydro-7-methyl-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphthalene[1,2-c]-furan-1,3-dione 1,3,3a,4,5,9b-hexahydro-7-ethyl-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphthalene [1,2-c]- Furan-1,3-diketone, 1,3,3a,4,5,9 B-Hexahydro-8-methyl-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphthalene[1,2-c]-furan-1,3-dione, 1, 3,3a,4,5,9b-hexahydro-8-ethyl-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphthalene[1,2-c]-furan-1 ,3-dione, 1,3,3a,4,5,9b-hexahydro-5,8-dimethyl-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphthalene [1,2-c]-furan-1,3-dione, 5-(2,5-dioxotetrahydrofuranyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, Bicyclo[2.2.2]-oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 3-oxabicyclo[3.2.1]octane-2,4-dione-6-spiro -3'-(tetrahydrofuran-2',5'-dione), 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2 -dicarboxylic anhydride, 3,5,6-tricarboxy-2-carboxynorbornane-2:3,5:6-dianhydride, 4,9-dioxatricyclo[5.3.1.0 ^2,6 ] An aliphatic or alicyclic tetracarboxylic dianhydride such as a compound represented by the following formula (TI) or (T-II); or alkane-3,5,8,10-tetraketone;

(In the formulae (TI) and (T-II), R ¹ and R ³ represent a divalent organic group having an aromatic ring, R ² and R ⁴ represent a hydrogen atom or an alkyl group, and a plurality of R ² and R ^{4 are present.} Each can be the same or different).

3,3',4,4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-diphenylphosphonium tetracarboxylic dianhydride, 1,4,5,8-naphthalene tetracarboxylate Acid dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride, 3,3',4,4'-di Methyldiphenylnonanetetracarboxylic dianhydride, 3,3',4,4'-tetraphenylnonanetetracarboxylic dianhydride, 1,2,3,4-furantetracarboxylic dianhydride, 4,4 '-Bis(3,4-dicarboxyphenoxy)diphenyl sulfide dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenyl phthalic anhydride, 4,4' - bis(3,4-dicarboxyphenoxy)diphenylpropane dianhydride, 3,3',4,4'-perfluoroisopropylidene diphthalic dianhydride, 3,3',4 , 4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, bis(phthalic acid)phenylphosphine oxide dianhydride, p-phenylene-bis (triphenylphthalic acid) dianhydride, m-phenylene-bis(triphenylphthalic acid) dianhydride, bis(triphenylphthalic acid)-4,4'-diphenyl ether Anhydride, bis(triphenylphthalic acid)-4,4'-diphenylmethane dianhydride, ethylene glycol-bis(hydroper trimellitate), propylene glycol-bis(anhydrotrimellitic acid ester) 1,4-butanediol-double (dehydrated benzene) Acid ester), 1,6-hexanediol-bis(hydrogen trimellitate), 1,8-octanediol-bis(hydroper trimellitate), 2,2-bis(4-hydroxybenzene) An aromatic tetracarboxylic dianhydride such as a compound represented by the following formulas (T-1) to (T-4); a propane-bis(hydrogen trimellitate). They may be used alone or in combination of two or more.

Among them, from the viewpoint of enabling liquid crystal alignment which is excellent in performance, butane tetracarboxylic dianhydride and 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid are preferred. Anhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 1,3,3a,4,5,9b-hexahydro-5 -(tetrahydro-2,5-dioxo-3-furanyl)-naphthalene[1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-six Hydrogen-8-methyl-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphthalene[1,2-c]-furan-1,3-dione, 1,3,3a ,4,5,9b-hexahydro-5,8-dimethyl-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphthalene[1,2-c]-furan-1 ,3-dione, bicyclo[2.2.2]-oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 3-oxabicyclo[3.2.1]octane-2,4- Diketo-6-spiro-3'-(tetrahydrofuran-2',5'-dione), 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclo Hexene-1,2-dicarboxylic anhydride, 3,5,6-tricarboxy-2-carboxynorbornane-2:3,5:6-dianhydride, 4,9-dioxatricyclo[5.3. 1.0 ^2,6 ]undecane-3,5,8,10-tetraketone, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-di Phenylhydrazine tetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, represented by the above formula (TI) Composition in the following formula (T-5) ~ (T-7) and a compound represented by the above formula (T-II) compound (T-8) represented by the compound represented by the following formula. A particularly preferred other tetracarboxylic dianhydride is 2,3,5-tricarboxycyclopentyl acetic acid dianhydride.

The tetracarboxylic dianhydride used in the synthesis of the polyamic acid contained in the liquid crystal alignment agent of the present invention preferably contains 60 to 99 mol% of 1,2,3,4-ring relative to all tetracarboxylic dianhydride. The butane tetracarboxylic dianhydride preferably contains 65 to 97 mol%. Further, it contains 1 to 10 mol% of pyromellitic dianhydride with respect to all of the tetracarboxylic dianhydride, and the value is preferably 2 to 10 mol%.

The tetracarboxylic dianhydride used for the synthesis of the polyamic acid contained in the liquid crystal alignment agent of the present invention preferably further contains 50 mol% or less as the other tetracarboxylic dianhydride with respect to all the tetracarboxylic dianhydride. 2,3,5-tricarboxycyclopentyl acetic acid dianhydride. More preferably, it contains 10 to 40 mol%, and further preferably contains 15 to 35 mol%.

By using a tetracarboxylic dianhydride containing each tetracarboxylic dianhydride in the above ratio, a polymer exhibiting good solubility with respect to the following solvent can be obtained, and the liquid crystal alignment film formed of the liquid crystal alignment agent containing the same is excellent in the alignment property. From this point of view, it is better.

[diamine]

The diamine used in the synthesis of the polyamic acid contains the compound represented by the above formula (1). In the synthesis of the above polylysine, it is also possible to use a diamine other than the other.

Examples of these other diamines include diamines having a steroid skeleton and other diamines.

The diamine having a steroid skeleton may, for example, be a compound represented by the following formula (D-I).

(In the formula (DI), X ¹ represents a divalent organic group selected from the group consisting of -O-, -COO-, -OCO-, -NHCO-, -CONH-, and -CO-, and R ⁵ represents a steroid skeleton. a monovalent organic group), a compound represented by the following formula (D-II),

(In the formula (D-II), X ² represents a divalent organic group selected from the group consisting of -O-, -COO-, -OCO-, -NHCO-, -CONH-, and -CO-, and R ⁶ represents a steroid a divalent organic group of the skeleton). As a specific example of the compound represented by the above formula (DI), for example, a compound represented by the following formulas (D-1) to (D-6);

The compound represented by the above formula (D-II) may, for example, be a compound represented by the following formulas (D-7) to (D-9).

Examples of the other diamine include p-phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylethane, and 4,4. '-Diaminodiphenyl sulfide, 4,4'-diaminodiphenylanthracene, 3,3'-dimethyl-4,4'-diaminobiphenyl, 4,4'-di Aminobenzamide, 4,4'-diaminodiphenyl ether, 1,5-diaminonaphthalene, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3, 3'-Dimethyl-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 3,3'-bis (three Fluoromethyl)-4,4'-diaminobiphenyl, 5-amino-1-(4'-aminophenyl)-1,3,3-trimethylindan, 6-amino group- 1-(4'-Aminophenyl)-1,3,3-trimethylindan, 3,4'-diaminodiphenyl ether, 3,3'-diaminobenzophenone, 3 , 4'-diaminobenzophenone, 4,4'-diaminobenzophenone, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-double [4-(4-Aminophenoxy)phenyl]hexafluoropropane, 2,2-bis(4-aminophenyl)hexafluoropropane, 2,2-bis[4-(4-aminobenzene) Oxy)phenyl]anthracene, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-amino Oxy)benzene, 9,9-bis(4-aminophenyl)-10-hydroquinone, 2,7-diaminoguanidine, 9,9-dimethyl-2,7-diaminoguanidine, 9,9-bis(4-aminophenyl)anthracene, 4,4'-methylene-bis(2-chloroaniline), 2,2',5,5'-tetrachloro-4,4'- Diaminobiphenyl, 2,2'-dichloro-4,4'-diamino-5,5'-dimethoxybiphenyl, 3,3'-dimethoxy-4,4'- Diaminobiphenyl, 1,4,4'-(p-phenylene isopropylidene)diphenylamine, 4,4'-(m-phenyleneisopropylene)diphenylamine, 2,2'-double [4-(4-Amino-2-trifluoromethylphenoxy)phenyl]hexafluoropropane, 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl, An aromatic diamine such as 4,4'-bis[(4-amino-2-trifluoromethyl)phenoxy]-octafluorobiphenyl;

1,1-m-xylylenediamine, 1,3-propanediamine, butanediamine, pentamethylenediamine, hexamethylenediamine, heptanediamine, octanediamine, decanediamine, 4,4-diaminoglycol Diamine, 1,4-diaminocyclohexane, isophoronediamine, tetrahydrodicyclopentadiene diamine, hexahydro-4,7-methylene dimethylene diamine, tricyclic [6.2.1.0 ^2,7 ] undecene dimethyl diamine, 4,4′-methylene bis(cyclohexylamine), 1,3-bis(aminomethyl)cyclohexane, 1, An aliphatic or alicyclic diamine such as 4-bis(aminomethyl)cyclohexane;

2,3-diaminopyridine, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 5,6-diamino-2,3-dicyanide Kiti ,5,6-diamino-2,4-dihydroxypyrimidine, 2,4-diamino-6-dimethylamino-1,3,5-three 1,4-bis(3-aminopropyl)per 2,4-Diamino-6-isopropoxy-1,3,5-three 2,4-diamino-6-methoxy-1,3,5-three 2,4-diamino-6-phenyl-1,3,5-three 2,4-diamino-6-methyl-s-three 2,4-diamino-1,3,5-three 4,6-Diamino-2-vinyl-s-three , 2,4-Diamino-5-phenylthiazole, 2,6-diaminopurine, 5,6-diamino-1,3-dimethyluracil, 3,5-diamino- 1,2,4-triazole, 6,9-diamino-2-ethoxyacridine lactate, 3,8-diamino-6-phenylphenanthridine, 1,4-diamine Piper , 3,6-diaminoacridine, bis(4-aminophenyl)phenylamine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, N -ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N,N-bis(4-aminophenyl)benzidine, the following formula (D a compound represented by -III),

(In the formula (D-III), R ⁷ represents a compound selected from the group consisting of pyridine, pyrimidine, and Piperidine and piperazine a monovalent organic group having a cyclic structure containing a nitrogen atom, X ³ represents a divalent organic group), a compound represented by the following formula (D-IV),

(In the formula (D-IV), R ⁸ represents a compound selected from the group consisting of pyridine, pyrimidine, and Piperidine and piperazine a divalent organic group having a cyclic structure containing a nitrogen atom, X ⁴ represents a divalent organic group, and a plurality of X ⁴ groups present may be the same or different) and have two primary amine groups in the molecule and a diamine of a nitrogen atom other than the primary amine group;

a compound represented by the following formula (D-V),

(In the formula (DV), X ⁵ represents a divalent organic group selected from -O-, -COO-, -OCO-, -NHCO-, -CONH-, and -CO-, and R ⁹ represents a fluorine atom; a valence organic group or an alkyl group having 6 to 30 carbon atoms; a compound represented by the following formula (D-VI),

(In the formula (D-VI), R ¹⁰ represents a hydrocarbon group having 1 to 12 carbon atoms, and a plurality of R ¹⁰ groups may be the same or different, p is an integer of 1 to 3, and q is 1 to 20. Integer); a compound represented by the following formula (D-10) or (D-11),

(y in the formula (D-10) is an integer of 2 to 12, and z in the formula (D-11) is an integer of 1 to 5). These diamines may be used alone or in combination of two or more.

Among them, preferred are diamines having a steroid skeleton, p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfide, 1,5-diamino group. Naphthalene, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 2,7- Diamino hydrazine, 4,4'-diaminodiphenyl ether, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 9,9-bis(4-amino group Phenyl) guanidine, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2-bis(4-aminophenyl)hexafluoropropane, 4,4' -(p-phenylene diisopropylidene)diphenylamine, 4,4'-(m-phenylene diisopropylidene)diphenylamine, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 1,4-cyclohexanediamine, 4,4'-methylenebis(cyclohexylamine), 1,3-bis(amine Methyl)cyclohexane, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminoacridine, 3,6-di Amino carbazole, N-methyl-3,6-diaminocarbazole, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N,N'-bis(4-aminophenyl)benzidine, the following formula (D-12) in the compound represented by the above formula (D-III) Compounds illustrated, the compound represented by the above formula (D-IV) of the compound represented by the following formula (D-13),

Dodecyloxy-2,4-diaminobenzene, pentadecyloxy-2,4-diaminobenzene, hexadecyloxy-2,4- in the compound represented by the above formula (DV) Diaminobenzene, octadecyloxy-2,4-diaminobenzene, dodecyloxy-2,5-diaminobenzene, pentadecyloxy-2,5-diaminobenzene, Hexadecyloxy-2,5-diaminobenzene, octadecyloxy-2,5-diaminobenzene, a compound represented by the following formula (D-14) to (D-16) or the above formula 1,3-bis(3-aminopropyl)-tetramethyldioxane in the compound represented by (D-VI).

Particularly preferred other diamines are diamines having a steroid skeleton, and among them, preferred are compounds represented by the above formula (D-I) or (D-II).

The diamine used for the synthesis of the polyamic acid contained in the liquid crystal alignment agent of the present invention preferably contains 30 mol% or more of the compound represented by the above formula (1), more preferably 40 to 80 mol, based on the entire diamine. %, further preferably contains 50 to 75 mol%. The diamine used in the synthesis of the polyamic acid preferably contains 50 mol% or less of a diamine having a steroid skeleton with respect to all diamines, more preferably 10 to 30 mol%.

By using a diamine containing various diamines in the above ratio, a liquid crystal alignment agent capable of forming a liquid crystal alignment film excellent in voltage holding ratio and afterimage performance can be obtained, which is preferable.

[Synthesis of polyglycine]

The polyphthalic acid which may be contained in the liquid crystal alignment agent of the present invention may be 1 to 10 mol% by containing 1,2,3,4-cyclobutanetetracarboxylic dianhydride and relative to all tetracarboxylic dianhydride. The tetracarboxylic dianhydride of pyromellitic dianhydride is obtained by reacting a diamine containing the compound represented by the above formula (1).

The ratio of use of the tetracarboxylic dianhydride to the diamine to be supplied to the polyaminic acid synthesis reaction is preferably 0.5 to 2 equivalents based on the amine group of the equivalent of the diamine, and the acid anhydride group of the tetracarboxylic dianhydride is 0.5 to 2 equivalents. Preferably, it is a ratio of 0.7 to 1.2 equivalents.

The synthesis reaction of polylysine is preferably carried out in an organic solvent, preferably at a temperature of -20 to 150 ° C, more preferably 0 to 100 ° C, preferably 1 to 48 hours, more preferably 2 to 12 hour. Here, the organic solvent is not particularly limited as long as it can dissolve the produced polyamic acid, and examples thereof include 1-methyl-2-pyrrolidone, N,N-dimethylacetamide, and N,N. - dimethylformamide, 3-butoxy-N,N-dimethylpropanamide, 3-methoxy-N,N-dimethylpropanamide, 3-hexyloxy-N, An aprotic compound such as guanamine such as N-dimethylpropionamide, dimethyl hydrazine, γ-butyrolactone, tetramethyl urea or hexamethylphosphonium triamine; m-methylphenol, two A phenolic compound such as cresol, phenol or halogenated phenol. The amount (a) of the organic solvent is usually preferably an amount such that the total amount (b) of the tetracarboxylic dianhydride and the diamine compound is from 0.1 to 30% by weight based on the total amount (a+b) of the reaction solution.

In the organic solvent, a solvent alcohol, a ketone, an ester, an ether, a halogenated hydrocarbon, a hydrocarbon, or the like may be used in combination with the polyglycine which is not precipitated. . Specific examples of such a poor solvent include methanol, ethanol, isopropanol, cyclohexanol, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol, propylene glycol, and 1,4-butane. Alcohol, triethylene glycol, ethylene glycol monomethyl ether, ethyl lactate, butyl lactate, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, acetic acid Ester, methyl methoxypropionate, ethyl ethoxypropionate, diethyl oxalate, diethyl malonate, diethyl ether, ethylene glycol methyl ether, ethylene glycol ether, ethylene glycol n-propyl ether, B Glycol isopropyl ether, ethylene glycol n-butyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diglyme, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, digan Alcohol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, tetrahydrofuran, dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane Alkane, chlorobenzene, o-dichlorobenzene, hexane, heptane, octane, benzene, toluene, xylene, diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, isoamyl ether, and the like.

When the organic solvent is used in combination with the poor solvent, the amount of the poor solvent to be used can be appropriately set within a range in which the produced polyaminic acid is not precipitated, and is preferably 30% by weight or less, and more preferably 20% based on the total amount of the solvent. Below weight%.

As described above, a reaction solution in which polylysine was dissolved was obtained. The reaction solution may be directly supplied to the liquid crystal alignment agent, or the polyamic acid contained in the reaction solution may be separated and supplied to the liquid crystal alignment agent, or the separated polyamic acid may be refined. The preparation of the liquid crystal alignment agent is supplied. The separation of the polyamic acid can be carried out by adding the above-mentioned reaction solution to a large amount of a poor solvent to obtain a precipitate, and drying the precipitate under reduced pressure, or by subjecting the reaction solution to distillation under reduced pressure by an evaporator. Further, the polyaminic acid can be purified by performing the method of dissolving the polyamic acid in an organic solvent once or several times, and then precipitating it with a poor solvent or by vacuum distillation using an evaporator.

<醯iminated polymer>

The ruthenium iodide polymer which can be contained in the liquid crystal alignment agent of the present invention can be obtained by subjecting the above polyglycine to dehydration ring closure to carry out hydrazine imidization.

The tetracarboxylic dianhydride used for the synthesis of the above quinone imidized polymer may, for example, be the same compound as the tetracarboxylic dianhydride used in the synthesis of the above polyamic acid. In addition, examples of the diamine used in the synthesis of the ruthenium iodide polymer contained in the liquid crystal alignment agent of the present invention include the same diamines as those used in the synthesis of the polyamic acid.

The ruthenium iodide polymer contained in the liquid crystal alignment agent of the present invention may be a complete ruthenium imide of a lysine structure in which the lysine structure contained in the poly phthalic acid raw material is dehydrated and closed, or may be dehydrated only by a part of the proline structure. Closed-loop, a partial ruthenium imide of a proline structure with a quinone ring structure.

The ruthenium iodide polymer contained in the liquid crystal alignment agent of the present invention preferably has a ruthenium iodide ratio of 60% or more, more preferably 70% or more, further preferably 80% or more. By using a ruthenium iodide polymer having a ruthenium iodide ratio of 60% or more, a liquid crystal alignment agent capable of forming a liquid crystal alignment film excellent in afterimage performance can be obtained.

The above ruthenium amination ratio means a value expressed as a percentage of the ratio of the number of the quinone imine ring structure to the total amount of the guanidine structure and the quinone ring structure in the ruthenium iodide polymer. At this time, a part of the quinone ring may also be an isoindole ring. The hydrazine imidization rate can be determined by dissolving the ruthenium iodide polymer in a suitable deuterated solvent (for example, deuterated dimethyl hydrazine), using tetramethyl decane as a reference substance, and measuring ¹ H- at room temperature. NMR was determined from the measurement results according to the following formula (i).

醯 imidization rate (%) = (1-A ¹ /A ² ×α)×100 (i)

(In formula (i), A ¹ is the peak area originating from the NH proton present near the chemical shift of 10 ppm, A ² is the peak area derived from other protons, and α is relative to the ruthenium polymer precursor (poly One NH proton in proline), the ratio of the number of other protons).

The dehydration ring closure of polylysine is preferably (i) a method of heating poly-proline, or (ii) by dissolving poly-proline in an organic solvent, adding a dehydrating agent and a dehydration ring-closing catalyst to the solution according to It needs to be carried out by heating.

The reaction temperature in the method of heating poly-proline in the above (i) is preferably from 50 to 200 ° C, more preferably from 60 to 170 ° C. The reaction time is preferably from 1 to 120 hours, more preferably from 2 to 48 hours. When the reaction temperature is less than 50 ° C, the dehydration ring closure reaction cannot be sufficiently carried out. When the reaction temperature exceeds 200 ° C, the molecular weight of the obtained quinone imidized polymer may decrease.

On the other hand, in the method of adding the dehydrating agent and the dehydration ring-closure catalyst to the polyamic acid solution of the above (ii), as the dehydrating agent, an acid anhydride such as acetic anhydride, propionic anhydride or trifluoroacetic anhydride can be used. The amount of the dehydrating agent is determined depending on the desired hydrazine imidization ratio, and is preferably 0.01 to 20 moles per mole of the proline structure of 1 mole of polyamic acid. Further, as the dehydration ring-closure catalyst, for example, a tertiary amine such as pyridine, trimethylpyridine, lutidine or triethylamine can be used. However, it is not limited to these. The amount of the dehydration ring-closure catalyst is preferably from 0.01 to 10 mols per mol of the dehydrating agent used. The higher the amount of the above dehydrating agent and the dehydration ring-closure catalyst, the higher the yield of ruthenium. The organic solvent used in the dehydration ring-closure reaction may, for example, be an organic solvent exemplified as a solvent used in the synthesis of polylysine. The reaction temperature of the dehydration ring closure reaction is preferably from 0 to 180 ° C, more preferably from 10 to 150 ° C. The reaction time is preferably from 1 to 24 hours, more preferably from 2 to 8 hours.

In the above method (ii), a reaction solution containing the ruthenium iodide polymer as described above is obtained. The reaction solution may be directly supplied to the liquid crystal alignment agent, or may be supplied to the liquid crystal alignment agent after removing the dehydrating agent and the dehydration ring-closing catalyst from the reaction solution, and may also be separated from the sulfiminated polymer and then supplied to the liquid crystal alignment agent. The preparation may be carried out, or the separated quinone imidized polymer may be purified and then supplied to a liquid crystal alignment agent. The dehydrating agent and the dehydration ring-closure catalyst are removed from the reaction solution, and a method such as solvent replacement can be employed. The separation and purification of the ruthenium iodide polymer can be carried out in the same manner as the above-described separation and purification method as polyglycine.

- terminal modified polymer -

The poly-proline or quinone imidized polymer contained in the liquid crystal alignment agent of the present invention may also be a terminal-modified polymer having a molecular weight adjusted. By using such a terminal-modified polymer, the coating characteristics and the like of the liquid crystal alignment agent can be further improved without impairing the effects of the present invention. Such a terminal-modified polymer can be produced by adding a molecular weight modifier to a reaction system during the synthesis of poly-proline. Examples of the molecular weight modifier include a monobasic acid anhydride, a monoamine compound, and a monoisocyanate compound.

As the above monobasic acid anhydride, for example, maleic anhydride, phthalic anhydride, itaconic anhydride, n-decyl succinic anhydride, n-dodecyl succinic anhydride, n-tetradecyl succinic anhydride, n-hexadecyl amber may be mentioned. Anhydride, etc. Examples of the above monoamine compound include aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-decylamine, n-decylamine, n-undecylamine, and positive ten. Dialkylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecaneamine, n-octadecylamine, n-icosylamine, and the like. The monoisocyanate compound may, for example, be phenyl isocyanate or naphthyl isocyanate.

The use ratio of the molecular weight modifier is preferably 20 parts by weight or less, more preferably 10 parts by weight or less based on the total amount of the tetracarboxylic dianhydride and the diamine used in the synthesis of the polyglycolic acid.

- solution viscosity -

The polyaminic acid or quinone imidized polymer obtained as above preferably has a solution viscosity of 20 to 800 mPa·s when formulated into a solution having a concentration of 10% by weight, more preferably a solution viscosity of 30 to 500 mPa·s. .

The solution viscosity (mPa ‧ s) of the above polymer is prepared by using a good solvent (for example, γ-butyrolactone) of the polymer to prepare a polymer solution having a concentration of 10% by weight, and using an E-type rotational viscometer at 25 ° C Measured value.

<Other additives>

The liquid crystal alignment film of the present invention contains at least one polymer selected from the group consisting of polylysine as described above and its ruthenium iodide polymer. The polymer contained in the liquid crystal alignment agent of the present invention is preferably a ruthenium iodide polymer.

The liquid crystal alignment film of the present invention contains the polymer as described above as an essential component, and may further contain other components as needed. Examples of such other components include a compound having two or more epoxy groups in the molecule (hereinafter referred to as "epoxy compound"), a functional decane compound, and the like.

Examples of the epoxy group compound include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, and neopentyl Alcohol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerol diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl Base-2,4-hexanediol, N,N,N',N'-tetraglycidyl-m-xylylenediamine, 1,3-bis(N,N-diglycidylaminomethyl) Cyclohexane, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, 3-(N-allyl-N-glycidyl)aminopropyl Trimethoxy decane, 3-(N,N-diglycidyl)aminopropyltrimethoxydecane, and the like.

The use ratio of the above epoxy group compound is preferably 40 with respect to 100 parts by weight of the total amount of the polymer (refer to the total amount of the above polylysine and its ruthenium iodide polymer contained in the liquid crystal alignment agent). It is more preferably 0.1 to 30 parts by weight, based on the parts by weight.

The functional decane compound may, for example, be 3-aminopropyltrimethoxydecane, 3-aminopropyltriethoxydecane, 2-aminopropyltrimethoxydecane or 2-aminopropyl. Triethoxy decane, N-(2-aminoethyl)-3-aminopropyltrimethoxydecane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxy Baseline, 3-ureidopropyltrimethoxydecane, 3-ureidopropyltriethoxydecane, N-ethoxycarbonyl-3-aminopropyltrimethoxydecane, N-ethoxycarbonyl-3 -Aminopropyltriethoxydecane, N-triethoxydecylpropyltriethylenetriamine, N-trimethoxydecylpropyltriethylenetriamine, 10-trimethoxydecane-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(oxyethylene)- 3-aminopropyl three Silane group, N- bis (oxyethylene) -3-aminopropyl triethoxy silane-like.

The use ratio of the above functional decane compound is preferably 2 parts by weight or less, more preferably 0.2 parts by weight or less based on 100 parts by weight of the total amount of the polymer.

<Liquid alignment agent>

The liquid crystal alignment agent of the present invention is preferably obtained by dissolving at least one selected from the group consisting of the above polyamic acid and its quinone imidized polymer, and optionally further mixing, if necessary, in an organic solvent.

The solvent exemplified as the solvent used in the polyamido acid synthesis reaction can be mentioned as the organic solvent. Further, it is also possible to appropriately select a poor solvent which can be used in combination as a synthetic reaction of polylysine.

Preferred examples of the organic solvent used in the liquid crystal alignment agent of the present invention include N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactone, and N,N-dimethylformamide. , N,N-dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, B Ethyl oxypropionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol n-propyl ether, ethylene glycol isopropyl ether, ethylene glycol n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, Ethylene glycol ethyl ether acetate, diglyme, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether An acid ester, isoamyl propionate, isoamyl isobutyrate, isoamyl ether, and the like. These solvents may be used singly or in combination of two or more.

In the liquid crystal alignment agent of the present invention, the solid content concentration (the ratio of the total weight of the liquid crystal alignment agent other than the solvent to the total weight of the liquid crystal alignment agent) is appropriately selected in consideration of viscosity, volatility, etc., preferably 1 to 10 parts by weight. The range of %. That is, the liquid crystal alignment agent of the present invention is applied to the surface of the substrate as described below, preferably by heating to form a coating film as a liquid crystal alignment film, and when the solid content concentration is less than 1% by weight, the thickness of the coating film is too small. However, a good liquid crystal alignment film cannot be obtained; on the other hand, when the solid content concentration exceeds 10% by weight, the thickness of the coating film is too thick to obtain a good liquid crystal alignment film, and the viscosity of the liquid crystal alignment agent increases. This leads to poor coating properties.

The particularly preferable solid content concentration range differs depending on the method used to apply the liquid crystal alignment agent to the substrate. For example, when the spin coating method is employed, it is particularly preferably in the range of 1.5 to 4.5% by weight. When the printing method is employed, it is particularly preferable that the solid content concentration is in the range of 3 to 9% by weight, so that the solution viscosity can be made to fall within the range of 12 to 50 mPa·s. When the ink jet method is employed, it is particularly preferable that the solid content concentration is in the range of 1 to 5% by weight, so that the solution viscosity can be made to fall within the range of 3 to 15 mPa·s.

The temperature at which the liquid crystal alignment agent of the present invention is prepared is preferably from 0 ° C to 200 ° C, more preferably from 20 ° C to 60 ° C.

<Liquid crystal display element>

The liquid crystal display element of the present invention has a liquid crystal alignment film formed of the liquid crystal alignment agent of the present invention as described above.

The liquid crystal display element of the present invention can be produced, for example, by the following steps (1) to (3).

(1) First, two substrates each having a patterned transparent conductive film are provided as a pair, and on each surface on which the transparent conductive film is formed, for example, a roll coating method, a spin coating method, an offset printing method, or an inkjet printing method The liquid crystal alignment agent of the present invention is applied by an appropriate coating method such as a method, and then a coating film is formed by heating each of the coated surfaces. Here, as the substrate, for example, glass such as float glass or soda lime glass; polyethylene terephthalate, polybutylene terephthalate, polyether oxime, polycarbonate, poly (aliphatic ring) can be used. Plastic transparent substrate such as olefin). As the transparent conductive film provided on one surface of the substrate, a NESA film made of tin oxide (SnO ₂ ) (registered trademark of PPG, USA), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ -SnO ₂ ), or the like can be used. The pattern-forming transparent conductive film can be obtained, for example, by a method of forming a pattern by photolithography after forming a transparent conductive film without a pattern, or a method of using a mask having a desired pattern when a transparent conductive film is formed, or the like. In the application of the liquid crystal alignment agent, in order to further improve the adhesion between the surface of the substrate and the transparent conductive film and the coating film, it is also possible to apply a functional decane compound or a functional member on the surface of the substrate surface on which the coating film is to be formed. Pretreatment of a titanium compound or the like.

The heating temperature after application of the liquid crystal alignment agent is preferably from 30 to 300 ° C, more preferably from 40 to 250 ° C, and the heating time is preferably from 1 to 30 minutes, more preferably from 5 to 20 minutes. The thickness of the formed coating film is preferably 0.001 to 1 μm, more preferably 0.005 to 0.5 μm.

(2) Then, the coating film surface formed as described above is subjected to a rubbing treatment in a certain direction by a roll wound with a cloth made of a fiber such as nylon, rayon, or cotton. Thus, the alignment energy of the liquid crystal molecules is generated on the coating film to form a liquid crystal alignment film. Further, the vertical alignment type liquid crystal display element is also not subjected to the rubbing treatment. In this case, the above coating film can be directly used as a liquid crystal alignment film.

In the liquid crystal alignment film which is formed by the liquid crystal alignment agent of the present invention, the liquid crystal is shown in, for example, the patent document 7 (JP-A-6-222366) or the patent document 8 (JP-A-6-281939). A process in which a part of the alignment film is irradiated with ultraviolet rays to change a pretilt angle of a partial region of the liquid crystal alignment film, or a protective film is formed on the surface of the liquid crystal alignment film portion as shown in Patent Document 9 (JP-A-5-107544). The treatment for removing the protective film after the sanding treatment is performed in a direction different from the previous polishing treatment, so that each region of the liquid crystal alignment film has a different liquid crystal alignment energy, which can improve the field of view characteristics of the obtained liquid crystal display element.

(3) A pair of substrates on which the liquid crystal alignment film is formed as described above are placed opposite to each other through a gap (cell gap), so that the polishing direction of the liquid crystal alignment film of the two substrates is perpendicular or anti-parallel, and the peripheral portions of the two substrates are bonded with a sealant. The liquid crystal is filled into the cell gap separated by the surface of the substrate and the sealant, and the injection hole is closed to form a liquid crystal cell. Then, a polarizing plate is attached to the outer surface of the liquid crystal cell so that the polarization direction thereof coincides with or is perpendicular to the rubbing direction of the liquid crystal alignment film formed on each of the substrates, whereby a liquid crystal display element can be obtained. Here, as the sealant, for example, an epoxy resin containing an alumina ball as a curing agent and a separator, or the like can be used. Examples of the liquid crystal include nematic liquid crystal and dish-shaped liquid crystal. Among them, a nematic liquid crystal is preferable, and for example, a Schiff's subtractive liquid crystal, an oxidized azo liquid crystal, a biphenyl liquid crystal, or a phenylcyclohexane can be used. Liquid crystal, ester liquid crystal, terphenyl liquid crystal, biphenyl cyclohexane liquid crystal, pyrimidine liquid crystal, dioxane liquid crystal, bicyclooctane liquid crystal, cubic liquid crystal liquid crystal, etc. Further, cholesteric liquid crystals such as cholesteryl cholesteryl, cholesteryl phthalate, and cholesteryl carbonate may be further added to these liquid crystals; and the trade names "C-15" and "CB-15" (manufactured by MERCK Co., Ltd.) may be further added. A chiral agent sold; used for ferroelectric liquid crystals such as decyloxybenzylidene-p-amino-2-methylbutyl cinnamate.

The polarizing plate to be bonded to the outer surface of the liquid crystal cell may be a polarizing plate or an H film which is obtained by sandwiching a polarizing film called "H film" obtained by stretching a polyvinyl alcohol and simultaneously absorbing iodine, in a protective film of acetate. A polarizing plate made by itself.

[Examples]

Hereinafter, the present invention will be more specifically described by way of examples, but the invention is not limited to the examples.

Further, in the following synthesis examples, the ruthenium imidization ratio in the ruthenium iodide polymer is dissolved in deuterated dimethyl sulfoxide by drying the ruthenium iodide polymer under reduced pressure at room temperature. ¹ H-NMR was measured at room temperature using tetramethyl decane as a reference material, and the measurement results were obtained according to the above formula (i).

Synthesis Example 1

93 g (0.48 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride as tetracarboxylic dianhydride and 5 g (0.03 mol) of pyromellitic dianhydride, and as a diamine compound 2,4-diamino-N,N-diallylaniline (compound represented by the above formula (1)) 81 g (0.4 mol) and 52 g (0.1 mol) of the compound represented by the above formula (D-3) The solution was dissolved in 928 g of N-methyl-2-pyrrolidone and reacted at 60 ° C for 6 hours to obtain a solution containing polylysine. A small amount of the obtained polyaminic acid solution was taken, and N-methyl-2-pyrrolidone was added to prepare a solution having a polyglycine concentration of 10% by weight, and the solution viscosity was measured to be 53 mPa·s.

Then, 1160 g of N-methyl-2-pyrrolidone was added to the obtained polyaminic acid solution, and 198 g of pyridine and 204 g of acetic anhydride were further added, and a dehydration ring-closure reaction was carried out at 110 ° C for 4 hours. After the dehydration ring-closure reaction, the solvent in the system is replaced with a new γ-butyrolactone solvent (in this operation, the pyridine and acetic anhydride used in the dehydration ring-closing oxime imidization reaction are removed to the outside of the system) to obtain about 1300 g of a solution containing a ruthenium iodide polymer (A-1) having a ruthenium iodide ratio of about 93%. A small amount of the ruthenium iodide polymer solution was added, and γ-butyrolactone was added to prepare a solution having a ruthenium iodide polymer concentration of 10% by weight, and the solution viscosity was measured to be 65 mPa·s.

Synthesis Example 2

93 g (0.48 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride as tetracarboxylic dianhydride and 5 g (0.03 mol) of pyromellitic dianhydride, and as a diamine compound 2,4-Diamino-N,N-diallylaniline 61g (0.3 mol) and 4-[4-(4-trans-n-heptylcyclohexyl)phenoxy]-1,3-di Aminobenzene 76 g (0.2 mol) was dissolved in 944 g of N-methyl-2-pyrrolidone, and reacted at 60 ° C for 6 hours to obtain a solution containing polylysine. A small amount of the obtained polyaminic acid solution was taken, and N-methyl-2-pyrrolidone was added to prepare a solution having a polyglycine concentration of 10% by weight, and the solution viscosity was measured to be 56 mPa·s.

Then, 1180 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, and 198 g of pyridine and 204 g of acetic anhydride were further added, and the dehydration ring-closure reaction was carried out at 110 ° C for 4 hours. After the dehydration ring closure reaction, the solvent in the system is replaced with a new γ-butyrolactone solvent (in this operation, the pyridine and acetic anhydride used in the dehydration ring-closure reaction are removed to the outside of the system) to obtain about 1300 g of yttrium. A solution of the ruthenium iodide polymer (A-2) having an amination rate of about 94%. A small amount of the ruthenium iodide polymer solution was added, and γ-butyrolactone was added to prepare a solution having a ruthenium iodide polymer concentration of 10% by weight, and the solution viscosity was measured to be 67 mPa·s.

Synthesis Example 3

1,2,3,4-cyclobutanetetracarboxylic dianhydride of tetracarboxylic dianhydride 64 g (0.33 mol), 2,3,5-tricarboxycyclopentyl acetic acid dianhydride 34 g (0.15 mol) And pyromellitic dianhydride 5g (0.03 mole), and 2,4-diamino-N,N-diallylaniline as a diamine compound 81g (0.4 mole) and the above formula (D- 3) The indicated compound 52 g (0.1 mol) was dissolved in 956 g of N-methyl-2-pyrrolidone, and reacted at 60 ° C for 6 hours to obtain a solution containing polylysine. A small amount of the obtained polyaminic acid solution was taken, and N-methyl-2-pyrrolidone was added to prepare a solution having a polyglycine concentration of 10% by weight, and the solution viscosity was measured to be 52 mPa·s.

Then, 1195 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, and 198 g of pyridine and 204 g of acetic anhydride were further added, and the dehydration ring-closure reaction was carried out at 110 ° C for 4 hours. After the dehydration ring closure reaction, the solvent in the system is replaced with a new γ-butyrolactone solvent (in this operation, the pyridine and acetic anhydride used in the dehydration ring closure reaction are removed to the outside of the system) to obtain about 1300 g of the solvent. A solution of the ruthenium iodide polymer (A-3) having a ruthenium iodide ratio of about 93%. A small amount of the ruthenium iodide polymer solution was added, and γ-butyrolactone was added to prepare a solution having a ruthenium polymer concentration of 10% by weight, and the solution viscosity was measured to be 63 mPa·s.

Comparative Synthesis Example 1

98 g (0.5 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride as tetracarboxylic dianhydride, and 2,4-diamino-N,N-di as a diamine compound 81 g (0.4 mol) of allylaniline and 52 g (0.1 mol) of the compound represented by the above formula (D-3) were dissolved in 926 g of N-methyl-2-pyrrolidone, and reacted at 60 ° C for 6 hours to obtain a poly-containing poly A solution of proline. A small amount of the obtained polyaminic acid solution was taken, and N-methyl-2-pyrrolidone was added to prepare a solution having a polyglycine concentration of 10% by weight, and the solution viscosity was measured to be 52 mPa·s.

Then, 1158 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, and 198 g of pyridine and 204 g of acetic anhydride were further added, and the dehydration ring-closure reaction was carried out at 110 ° C for 4 hours. After the dehydration ring closure reaction, the solvent in the system is replaced with a new γ-butyrolactone solvent (in this operation, the pyridine and acetic anhydride used in the dehydration ring closure reaction are removed to the outside of the system) to obtain about 1300 g of the solvent. A solution of a ruthenium iodide polymer (B-1) having a ruthenium iodide ratio of about 93%. A small amount of the ruthenium iodide polymer solution was added, and γ-butyrolactone was added to prepare a solution having a ruthenium iodide polymer concentration of 10% by weight, and the solution viscosity was measured to be 62 mPa·s.

Comparative Synthesis Example 2

98 g (0.5 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride as tetracarboxylic dianhydride, and 2,4-diamino-N,N-di as a diamine compound Allyl aniline 61 g (0.3 mol) and 4-[4-(4-trans-n-heptylcyclohexyl)phenoxy]-1,3-diaminobenzene 76 g (0.2 mol) were dissolved in 941 g of N- The reaction was carried out at 60 ° C for 6 hours in methyl-2-pyrrolidone to obtain a solution containing polyglycine. A small amount of the obtained polyaminic acid solution was taken, and N-methyl-2-pyrrolidone was added to prepare a solution having a polyglycine concentration of 10% by weight, and the solution viscosity was measured to be 48 mPa·s.

Then, 1177 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, and 198 g of pyridine and 204 g of acetic anhydride were further added thereto, and the dehydration ring-closure reaction was carried out at 110 ° C for 4 hours. After the dehydration ring closure reaction, the solvent in the system is replaced with a new γ-butyrolactone solvent (in this operation, the pyridine and acetic anhydride used in the dehydration ring closure reaction are removed to the outside of the system) to obtain about 1300 g of the solvent. A solution of a ruthenium iodide polymer (B-2) having a ruthenium iodide ratio of about 95%. A small amount of the ruthenium iodide polymer solution was added, and γ-butyrolactone was added to prepare a solution having a ruthenium polymer concentration of 10% by weight, and the solution viscosity was determined to be 55 mPa. s.

Comparative Synthesis Example 3

93 g (0.5 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 5 g (0.03 mol) of pyromellitic dianhydride as tetracarboxylic dianhydride, and as a diamine compound 4,4'-diaminodiphenyl ether 80 g (0.4 mol) and 52 g (0.1 mol) of the compound represented by the above formula (D-3) are dissolved in 944 g of N-methyl-2-pyrrolidone at 60 ° C The reaction was carried out for 6 hours to obtain a solution containing polylysine. A small amount of the obtained polyaminic acid solution was added, N-methyl-2-pyrrolidone was added, and a solution having a polyglycine concentration of 10% by weight was prepared, and the viscosity of the solution was measured to be 52 mPa. s.

Then, 924 g of N-methyl-2-pyrrolidone was added to the obtained polyaminic acid solution, and 198 g of pyridine and 204 g of acetic anhydride were further added thereto, and when the dehydration ring-closure reaction was carried out at 110 ° C for 4 hours, a gel-like polymer was precipitated. Since the gel polymer was insoluble in both N-methyl-2-pyrrolidone and γ-butyrolactone solvents, the subsequent analysis and evaluation were not performed.

Example 1

<Preparation of liquid crystal alignment agent>

To the solution containing the ruthenium iodide polymer (A-1) prepared in the above Synthesis Example 1, γ-butyrolactone (BL), N-methyl-2-pyrrolidone (NMP) and butyl cellosolve were added. (BC), a solution having a solvent composition of BL:NMP:BC=71:17:12 (weight ratio) and a solid content concentration of 4% by weight, and filtering the solution with a filter having a pore size of 1 μm to prepare a liquid crystal alignment Agent.

<Evaluation of Voltage Retention Rate>

The liquid crystal alignment agent prepared above was applied onto the transparent electrode surface of the glass substrate with the transparent electrode made of an ITO film on a hot plate at 80 ° C by using a liquid crystal alignment film printer (manufactured by Nippon Photo Printing Co., Ltd.). Heat for 1 minute, then heat on a 200 ° C hot plate for 10 minutes to form an average film thickness of 600 Coating film. This operation was repeated to produce two (a pair of) substrates having a coating film. When the coating film on these substrates was observed under a microscope with a magnification of 20 times, unevenness in printing and pinholes were not observed, and the coating property was good.

On the outer edges of the pair of substrates with the coating film having the liquid crystal alignment film, an epoxy resin adhesive having an alumina ball having a diameter of 5.5 μm is applied, and the liquid crystal alignment film faces are relatively overlapped. Press to cure the adhesive. Next, a negative liquid crystal (MLC-2038, manufactured by MERCK Co., Ltd.) was filled between the pair of substrates through a liquid crystal injection port, and then the liquid crystal injection port was sealed with an acrylic photocurable adhesive to obtain a liquid crystal cell for evaluating the voltage holding ratio.

A voltage of 5 V was applied to the liquid crystal cell at a temperature of 60 ° C for a time span of 167 msec, and the voltage application time was 60 μsec, and then the voltage holding ratio from the voltage release to 167 msec was measured. As the measuring device, VHR-1 manufactured by TOYO Corporation was used. When the voltage holding ratio was 95% or more, the voltage holding ratio was rated as "good", and in other cases, the voltage holding ratio was rated as "poor".

<Evaluation of afterimage performance>

A liquid crystal cell for evaluation of afterimage performance was produced in accordance with the method described in <Evaluation of Voltage Retention Rate> except that the substrate with the ITO electrode shown in Fig. 1 was used as the substrate. A DC voltage of 6.0 V was applied to the electrode A at room temperature, and a DC voltage of 0.5 V was applied to the electrode B for 24 hours. After the voltage was released, the difference in luminance between the electrodes A and B in the respective regions when the electrodes A and B were applied with a DC voltage of 0.1 to 5.0 V in a gradient of 0.1 V was evaluated. When the luminance difference is small, the afterimage performance is evaluated as "good", and when the luminance difference is large, the afterimage performance is evaluated as "poor".

Examples 2 and 3 and Comparative Examples 1 and 2

A liquid crystal alignment agent was prepared and evaluated in the same manner as in Example 1 except that a solution containing the polymer listed in Table 1 was used instead of the solution containing the ruthenium iodide polymer (A-1). The evaluation results are shown in Table 1.

Fig. 1 is a schematic view showing a liquid crystal cell manufactured by evaluation of afterimage performance.

Claims (5)

A liquid crystal alignment agent characterized by comprising at least one polymer selected from the group consisting of polylysine and a ruthenium iodide polymer thereof, and a liquid crystal alignment film for forming a vertical alignment type liquid crystal display element; Polylysine is prepared by reacting a tetracarboxylic dianhydride with a diamine containing 1,2,3,4-cyclobutanetetracarboxylic dianhydride and relative to all tetracarboxylic dianhydride It is 1 to 10 mol% of pyromellitic dianhydride, and the diamine contains a compound represented by the following formula (1) and a diamine having a steroid skeleton of 10 to 50 mol% based on the entire diamine. The liquid crystal alignment agent according to claim 1, wherein the tetracarboxylic dianhydride further contains 2,3,5-tricarboxycyclopentyl acetic acid dianhydride. The liquid crystal alignment agent according to claim 1 or 2, further comprising a compound having two or more epoxy groups in the molecule. A method for forming a liquid crystal alignment film of a vertical alignment type liquid crystal display device, which comprises applying a liquid crystal alignment agent according to any one of claims 1 to 3 to form a coating film, and then heating the coating film. It is characterized in that the method does not polish the coating film. A liquid crystal alignment film which is formed by a liquid crystal alignment agent according to any one of claims 1 to 3, which is formed without any polishing treatment.