TWI433870B - 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.

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 known, which forms a liquid crystal alignment made of polyimide or the like on the surface of a substrate on which a transparent conductive film is provided. The film is provided as a substrate for a liquid crystal display element, and a pair of (two pieces) are opposed to each other, and a nematic liquid crystal layer having positive dielectric anisotropy is filled in the gap to form a cell of a sandwich structure, and the liquid crystal molecule The long axis is continuously twisted 90 degrees from one substrate to the other. Further, an STN (Super Twisted Nematic) type liquid crystal display element having a higher load ratio than a TN type liquid crystal display element has recently been developed. Such an STN type liquid crystal display device uses a substance which is a chiral agent which is an optically active substance in a nematic liquid crystal, and is used as a liquid crystal by a continuous twist of 180 degrees or more between substrates by the long axis of the liquid crystal molecule. The birefringence effect produced by the state. The alignment of the liquid crystals in these TN type liquid crystal display elements and STN type liquid crystal display elements is usually produced by a liquid crystal alignment film which has been subjected to a rubbing treatment.

Further, as a liquid crystal display element of a different type from these, a VA (Vertical Alignment) type liquid crystal display element in which liquid crystal molecules having negative dielectric anisotropy are vertically aligned on a substrate is also known. In the VA liquid crystal display device, when a voltage is applied between the substrates to tilt the liquid crystal molecules in a direction parallel to the substrate, it is necessary to tilt the liquid crystal molecules from the substrate normal direction in one direction in the substrate surface. As a means for this purpose, for example, an MVA method in which protrusions are formed on ITO to control the alignment direction of liquid crystals (Patent Document 1 and Non-Patent Document 1), and an EVA method in which an electrode structure is designed to control an alignment direction has been proposed (Non-Patent Document 2) In the light alignment method in which the alignment film is modified by light irradiation to control the alignment direction (see Non-Patent Document 3).

On the other hand, polyimine which is obtained by polycondensation of tetracarboxylic dianhydride and diamine is known to have excellent heat resistance and chemical resistance. Therefore, polyimine is used in various applications, particularly in the fields of electricity and electronic materials, and has been widely used as a protective material, an insulating material, and the like. In particular, in the use of an alignment film of a liquid crystal display element, from the viewpoint of durability of a coating film, polyiphthalimide has hitherto been mainly used. However, in order to improve the performance of the liquid crystal display element and increase the density of the display, the surface properties of the polyimide have been particularly emphasized, and the prior polyimine alignment film has also been required to have excellent performance. For example, liquid crystal alignment control force, pretilt performance, afterimage performance, and the like are required to exhibit higher performance.

A liquid crystal alignment film made of polyimine, usually, a liquid crystal solution of a soluble sulfonium imidized polymer which is a polyaminic acid precursor which is a polyimine precursor or a dehydration ring-closing thereof The alignment agent is applied to the substrate and heated to imidize the oxime. According to Patent Document 2, by using the formula (III) or (IV)

(in the formulae (III) and (IV), n2 is 4 or 6 each)

The liquid crystal alignment agent of the polyamine synthesized polyamine or the quinone imidized polymer of the structure represented by the structure can form a liquid crystal alignment film capable of producing a stable pretilt angle. This technique achieves stabilization of the pretilt angle by introducing a liquid crystal-like skeleton derived from the diamine represented by the above formula (III) or (IV) onto the liquid crystal alignment film. It is said that a liquid crystal alignment film for a VA liquid crystal display element (hereinafter also referred to as "vertical alignment type liquid crystal alignment film") having excellent vertical alignment properties can be formed by using a polymer having such a structure. However, in Patent Document 2, the voltage holding ratio and the afterimage performance are not improved.

Further, in Patent Document 3, it is reported that it is synthesized by using a 3,5,6-tricarboxy-2-carboxymethylnorbornane-2:3,5:6-dianhydride as a tetracarboxylic dianhydride. The liquid crystal alignment agent of the polymer can achieve high voltage retention in the high temperature field. However, this technique still does not achieve an improvement in afterimage performance.

Here, in recent years, attention has been paid to the development of liquid crystal display elements. For example, as a method of filling a liquid crystal material into a gap between a pair of substrates, a pair of substrates are previously disposed to face each other through a gap, and a method of collecting liquid crystal into the gap is employed. In recent years, as a new method of replacing it, a one-drop filling (ODF) method has been proposed (Patent Document 4). The ODF method is a method in which droplets of a liquid crystal material are dropped on a liquid crystal alignment film of a substrate, and the liquid crystal droplets are extruded and expanded with respect to the opposite substrate, and the substrate is bonded under vacuum. According to this method, there is an advantage that the time required for the liquid crystal filling step can be greatly shortened, but dripping marks are generated in the liquid crystal dropping portion, and when it is made into a liquid crystal display element, it can be pointed out that the liquid crystal display element can be visually observed. The problem of uneven alignment. This liquid crystal is unevenly distributed, and it is considered that the alignment of the liquid crystal alignment film is partially disturbed by the impact when the liquid crystal material is dropped onto the liquid crystal alignment film. In order to solve this problem, an attempt has been made to solve the problem by the liquid crystal alignment film material (Patent Document 5), but it is still not satisfactory. In particular, when the VA liquid crystal display element is manufactured by the ODF method, it is required to suppress the above-described liquid crystal alignment unevenness.

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

[Patent Document 2] Japanese Patent Laid-Open No. 09-278724

[Patent Document 3] Japanese Patent Laid-Open No. Hei 11-84391

[Patent Document 4] Japanese Patent Laid-Open Publication No. 6-3635

[Patent Document 5] Japanese Patent Laid-Open Publication No. 2007-183564

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

[Patent Document 7] Japanese Patent Laid-Open No. Hei 6-281937

[Patent Document 8] Japanese Patent Laid-Open No. Hei 5-170044

[Patent Document 9] Japanese Patent Laid-Open No. Hei 4-281427

[Non-Patent Document 1] "Liquid Crystal", Vol. 3, No. 2, 117 (1999)

[Non-Patent Document 2] "Liquid Crystal", Vol. 3, No. 4, 272 (1999)

[Non-Patent Document 3] "Jpn J. Appl. phys." Vol 36, L428 (1997)

A first object of the present invention is to provide a liquid crystal alignment agent capable of forming a liquid crystal alignment film excellent in voltage holding ratio and afterimage performance. A second object of the present invention is to provide a liquid crystal alignment agent which can form a liquid crystal alignment film which does not cause liquid crystal alignment unevenness due to liquid crystal dropping even when the ODF method is employed in the liquid crystal filling step. Such a liquid crystal alignment agent of the present invention can be particularly preferably used for the formation of a liquid crystal alignment film of a vertical alignment type liquid crystal display element.

Another object of the present invention is to provide a liquid crystal display element excellent in display quality.

Other objects and advantages of the invention will be apparent from the description which follows.

The present inventors have conducted intensive studies in view of the above circumstances, and as a result, it has been found that a liquid crystal alignment film excellent in voltage holding ratio and afterimage performance can be formed by using a liquid crystal alignment agent containing a specific polymer synthesized using a diamine having a specific structure. Thus, the present invention has been achieved.

That is, the above objects and advantages of the present invention, first, achieved by a liquid crystal alignment agent comprising at least one polymer selected from the group consisting of polylysine and its quinone imidized polymer, the polyfluorene The amine acid is obtained by reacting a tetracarboxylic dianhydride with a diamine containing at least one selected from the group consisting of compounds represented by the following formulas (I) and (II),

(In the above formula, n1 is each independently an integer of 1 to 8).

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

The above objects and advantages of the present invention, and third, are achieved by the compound represented by the above formula (I) or (II).

The liquid crystal alignment agent of the present invention can form a liquid crystal alignment film excellent in voltage holding ratio and afterimage performance. Further, in the liquid crystal alignment agent of the present invention, even when the ODF method is employed in the liquid crystal filling step, a liquid crystal alignment film which does not cause liquid crystal alignment unevenness due to liquid crystal dropping can be formed. The liquid crystal alignment agent of the present invention can be used for a TN type and STN type liquid crystal display element, etc., and is particularly suitable for a VA type liquid crystal display element.

The liquid crystal display element of the present invention can be effectively used for various devices, for example, a display device which can be applied to a calculator, a watch, a desk clock, a counter display screen, a word processor, a personal computer, a liquid crystal television, or the like.

Hereinafter, the present invention will be specifically described.

The liquid crystal alignment agent of the present invention comprises at least one polymer selected from the group consisting of polylysine and a ruthenium imidized polymer thereof, the polyphthalic acid and the tetracarboxylic dianhydride are selected from the above formula ( The diamine reaction of at least one of the compounds represented by I) and (II) is carried out.

<tetracarboxylic dianhydride>

As the tetracarboxylic dianhydride which can be used for the synthesis of the polyamic acid used in the present invention, for example, butane tetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1, 2-Dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1, 3-Dichloro-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutane tetracarboxylic dianhydride 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3',4,4'-dicyclohexyltetracarboxylic acid Acid dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 2,3,4,5-tetrahydrofuran tetracarboxylic 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-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- Diketone, 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]-fur --1,3-diketone, 1,3,3a,4,5,9b-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-oxa Bicyclo[3.2.1]octane-2,4-dione-6-spiro-3'-(tetrahydrofuran-2',5'-dione), 5-(2,5-dioxotetrahydro-3) -furyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 3,5,6-tricarboxy-2-carboxymethylnorbornane-2:3,5:6- Di-anhydride, 4,9-dioxatricyclo[5.3.1.0 ^2,6 ]undecane-3,5,8,10-tetraone, represented by the following formulas (TI) and (T-II) An aliphatic or alicyclic tetracarboxylic dianhydride such as a compound;

(wherein R ¹ and R ³ each represent a divalent organic group having an aromatic ring, and R ² and R ⁴ each represent a hydrogen atom or an alkyl group, and a plurality of R ² and R ^{4 present} may be the same or different. Pyromellitic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-diphenylphosphonium tetracarboxylic dianhydride, 1, 4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride, 3, 3',4,4'-dimethyldiphenylnonanetetracarboxylic dianhydride, 3,3',4,4'-tetraphenylnonanetetracarboxylic dianhydride, 1,2,3,4-furan Tetracarboxylic dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenyl sulfide dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenyl Ruthenic anhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenylpropane dianhydride, 3,3',4,4'-perfluoroisopropylidene diphthalic acid Dihydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, bis(phthalic acid) phenylphosphine oxide Dihydride, p-phenylene-bis(triphenylphthalic acid) dianhydride, m-phenylene-bis(triphenylphthalic acid) dianhydride, bis(triphenylphthalic acid)- 4,4'-diphenyl ether dianhydride, bis(triphenyl) Phthalic acid)-4,4'-diphenylmethane dianhydride, ethylene glycol-bis(hydroper trimellitate), propylene glycol-bis(hydroper trimellitate), 1,4-butane Alcohol-bis(hydrogen trimellitate), 1,6-hexanediol-bis(anhydrotrimellitic acid ester), 1,8-octanediol-bis(anhydrotrimellitic acid ester), 2, An aromatic tetracarboxylic dianhydride such as 2-bis(4-hydroxyphenyl)propane-bis(hydrogen trimellitate) or a compound represented by the following formulas (T-1) to (T-4). They may be used alone or in combination of two or more.

In the above, the tetracarboxylic dianhydride used in the synthesis of the polyamic acid used in the present invention preferably contains a butane tetracarboxylic dianhydride from the viewpoint of being able to exhibit good liquid crystal alignment properties. 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4- Cyclopentane tetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 3,5,6-tricarboxy-2-carboxymethylnorbornane-2:3,5:6- Dihydride, 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-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-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 acid Anhydride, 3-oxabicyclo[3.2.1]octane-2,4-dione-6-spiro-3'-(tetrahydrofuran-2',5'-dione), 5-(2,5-di Oxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 3,5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5:6-dianhydride, 4,9-dioxatricyclo[5.3.1.0 ^2,6 ]undecane -3,5,8,10-tetraketone, pyromellitic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-diphenyl Based on tetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, a compound represented by the above formula (TI) At least a compound of the following formula (T-5) to (T-7) and at least one of the compounds represented by the following formula (T-8) in the compound represented by the above formula (T-II); A tetracarboxylic dianhydride (hereinafter referred to as "specific tetracarboxylic dianhydride").

As the specific tetracarboxylic dianhydride, it is preferably selected from 1,2,3,4-cyclobutanetetracarboxylic 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-hexahydro-8-methyl-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphthalene[1,2-c]-furan-1, 3-diketone, 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-carboxymethylnorbornane -2:3,5:6-dianhydride, 4,9-dioxatricyclo[5.3.1.0 ^2,6 ]undecane-3,5,8,10-tetraketone, pyromellitic dianhydride And at least one selected from the group consisting of the compounds represented by the above formula (T-1), particularly preferably 3,5,6-tricarboxy-2-carboxymethylnorbornane-2:3, 5:6-di anhydride.

The tetracarboxylic dianhydride used in the synthesis of the polyamic acid used in the present invention preferably contains 80 mol% or more of the specific tetracarboxylic dianhydride as described above with respect to all the tetracarboxylic dianhydride, more preferably It is contained in an amount of 90 mol% or more, and particularly preferably contains 95 mol% or more.

<Diamine>

The diamine used in the synthesis of the polyamic acid used in the present invention contains at least one selected from the group consisting of the compounds represented by the above formulas (I) and (II).

In the above formulae (I) and (II), n1 is preferably each an integer of from 3 to 6. The two amino groups bonded to the benzene ring are preferably located at the 2, 4 or 3, 5 position relative to the other substituents.

The compound represented by the above formula (I) can be obtained by, for example, dehydrohalogenating a corresponding 4-(4-(4-n-alkylcyclohexyl)cyclohexyl)phenol with a halogenated dinitrobenzene. The dinitro compound is reduced and synthesized. The compound represented by the above formula (II) can be obtained, for example, by subjecting the corresponding 4-(4-(4-n-alkylcyclohexyl)cyclohexyl)phenol to dinitrobenzoguanidine chloride for esterification reaction. The dinitro compound is reduced and synthesized.

The compound represented by each of the above formulas (I) and (II) may have a benzene ring optionally substituted by one or two alkyl groups having 1 to 4 carbon atoms (preferably a methyl group).

The diamine used in the synthesis of the polyamic acid used in the present invention may be at least one selected from the group consisting of the compounds represented by the above formulas (I) and (II), or may be selected from the above formula ( At least one of the compounds represented by each of I) and (II) is used in combination with other diamines.

Examples of the other diamine which can be used in combination herein include 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, R ⁶ represents an alkyl group having 1 to 4 carbon atoms, a1 represents an integer of 0 to 3, and a compound represented by the following formula (D-II).

(In the formula (D-II), X ² each represents a divalent organic group selected from the group consisting of -O-, -COO-, -OCO-, -NHCO-, -CONH-, and -CO-, and R ⁷ represents a ruthenium a divalent organic group having a bulk skeleton; each of R ⁸ each represents an alkyl group having 1 to 4 carbon atoms; and a2 each represents an integer of 0 to 3;

P-phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylethane, 4,4'-diaminodiphenyl sulfide, 4, 4'-Diaminodiphenylanthracene, 4,4'-diaminobenzamide, 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'-diamino linkage Benzene, 3,3'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 5-amino-1-(4'-aminophenyl)-1,3,3-trimethylhydrazine Full, 6-amino-1-(4'-aminophenyl)-1,3,3-trimethylindan, 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl Ketone, 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, bis[4-(4-aminophenoxy)phenyl]indole , 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 9,9- Bis(4-aminophenyl)-10-hydroquinone, 2,7-diaminopurine, 9,9-dimethyl-2,7-diaminopurine, 9,9-bis(4-aminophenyl)芴, 4, 4'-methylene-bis(2-chloroaniline), 2,2',5,5'-tetrachloro-4,4'-diaminobiphenyl, 2,2'-dichloro-4,4'-diamino-5,5'-dimethoxybiphenyl,3,3'-dimethoxy-4,4'-diaminobiphenyl,4,4'-(p-phenylene diisopropylene Diphenylamine, 4,4'-(m-phenylene diisopropylidene) bisaniline, 2,2'-bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl Hexafluoropropane, 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl, 4,4'-bis[(4-amino-2-trifluoromethyl)phenoxy An aromatic diamine such as octafluorobiphenyl or 4,4'-bis(4-aminophenoxy)biphenyl; 1,1-m-xylylenediamine, 1,3-propanediamine, butanediamine , pentanediamine, hexamethylenediamine, heptanediamine, octanediamine, decanediamine, 1,4-diaminocyclohexane, isophoronediamine, tetrahydrodicyclopentadienediamine, hexahydrogen -4,7-Methylene dimethylene diamine, tricyclo[6.2.1.0 ^2,7 ]undecene dimethyldiamine, 4,4'-methylenebis(cyclohexylamine), 1 , an aliphatic diamine such as 3-bis(aminomethyl)cyclohexane or 1,4-bis(aminomethyl)cyclohexane; and an alicyclic diamine; 2,3-diaminopyridine, 2,6- Diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 5,6-diamino-2,3- Cyano pyridine ,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-ethoxy acridine lactate, 3,8-diamino-6-phenylphenanthridine, 1,4-diaminopiper , 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, N,N'-bis(4-aminobenzene -N,N'-dimethylbenzidine, a compound represented by the following formula (D-III),

(In the formula (D-III), R ⁹ represents a compound selected from the group consisting of pyridine, pyrimidine, and tri Piperidine and piperazine a monovalent organic group having a cyclic structure of a nitrogen atom, X ³ represents a divalent organic group, R ¹⁰ represents an alkyl group having 1 to 4 carbon atoms, and a3 represents an integer of 0 to 3, and the following formula a compound represented by (D-IV),

(In the formula (D-IV), R ¹¹ represents a compound selected from the group consisting of pyridine, pyrimidine, and tri Piperidine and piperazine a divalent organic group having a cyclic structure of a nitrogen atom, each of X ⁴ represents a divalent organic group, and each of the plurality of X ⁴ present may be the same or different, and R ¹² each represents a carbon number of 1 to 4 a diamine having two primary amino groups and a nitrogen atom other than the primary amino group in the molecule such as an alkyl group, a4 each represents an integer of 0 to 3; a monosubstituted phenylenediamine such as a compound represented by the following formula (DV),

(In the formula (DV), X ⁵ represents a divalent organic group selected from the group consisting of -O-, -COO-, -OCO-, -NHCO-, -CONH-, and -CO-, and R ¹³ represents a group selected from trifluoro a monovalent organic group of a group in a methylphenyl group, a trifluoromethoxyphenyl group, and a fluorophenyl group; or an alkyl group having 6 to 30 carbon atoms; and R ¹⁴ represents a carbon number of 1 to 4; An alkyl group, a5 represents an integer of 0 to 3); a diaminoorganosiloxane such as a compound represented by the following formula (D-VI),

(In the formula (D-VI), R ¹⁵ each represents a hydrocarbon group having 1 to 12 carbon atoms, and a plurality of R ¹⁵ groups may be the same or different, each p is an integer of 1 to 3, and q is 1 to 2; An integer of 20); a compound represented by each of the following formulas (D-1) to (D-2),

(y in the formula (D-1) is an integer of 2 to 12, and z in the formula (D-2) is an integer of 1 to 5). The benzene ring of the above aromatic diamine and the compound represented by each of the above formulas (D-1) and (D-2) may be optionally one or two alkyl groups having 1 to 4 carbon atoms (preferably A). Base) replaced.

These diamines may be used alone or in combination of two or more.

R ⁶ , R ⁸ , R ¹⁰ , R ¹² and R ^{14 in the} above formulae (DI), (D-II), (D-III), (D-IV) and (DV) are each preferably a methyl group. Each of a1, a2, a3, a4 and a5 is preferably 0 or 1, more preferably 0.

The steroid skeleton in R ⁵ and R ⁶ of the above formulae (DI) and (D-II) means one or more of a skeleton composed of a cyclopentane-perhydrophenanthrene nucleus or a carbon-carbon bond thereof. Change to the skeleton of the double bond. The monovalent organic group of R ⁵ having such a steroid skeleton and the divalent organic group of R ⁶ each preferably have a group having from 17 to 40 carbon atoms, more preferably from 17 to 30 carbon atoms. Group.

Specific examples of R ⁵ include, for example, cholestyr-3-yl, cholest-5-en-3-yl, cholest-24-en-3-yl, cholester-5,24-diene- 3-yl, lanostan-3-yl, lanolin-5-en-3-yl, lanthene-24-en-3-yl, lanolin-5,24-dien-3-yl, etc.; Specific examples of R ⁶ include, for example, cholestane-3,6-diyl, cholest-5-ene-3,6-diyl, cholest-24-ene-3,6-diyl, cholesteric Alkane-3,3-diyl, lanostane-3,6-diyl, lanostane-3,3-diyl and the like.

Specific examples of the compound represented by the above formula (D-I) include compounds represented by the following formulas (D-3) to (D-7), respectively.

Specific examples of the compound represented by the above formula (D-II) include compounds represented by the following formulas (D-9) to (D-11), for example.

In the above-mentioned other diamine, at least one selected from the group consisting of a compound represented by the above formula (DI) and a compound represented by the above formula (D-II) (hereinafter referred to as "other specific two" is preferable. Amine (1)") and selected from the group consisting of p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfide, 1,5-diaminonaphthalene, 2,2'- Dimethyl-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 2,7-diaminopurine, 4,4'- Diaminodiphenyl ether, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 9,9-bis(4-aminophenyl)anthracene, 2,2-bis[4- (4-Aminophenoxy)phenyl]hexafluoropropane, 2,2-bis(4-aminophenyl)hexafluoropropane, 4,4'-(p-phenylene diisopropylidene) bisaniline, 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(aminomethyl)cyclohexane, 2,6-diaminopyridine, 3, 4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminoacridine, 3,6-diaminocarbazole, N-methyl-3,6-diamine Carbazole, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N,N'-bis(4-aminophenyl)benzidine, the above formula ( a compound represented by the following formula (D-12) and a compound represented by the following formula (D-13) in the compound represented by the above formula (D-IV),

Dodecyloxy-2,4-diaminobenzene, pentadecyloxy-2,4-diaminobenzene, hexadecyloxy-2,4-diamino in the compound represented by the above formula (DV) Benzene, octadecyloxy-2,4-diaminobenzene, dodecyloxy-2,5-diaminobenzene, pentadecyloxy-2,5-diaminobenzene, hexadecyloxy- 2,5-diaminobenzene, octadecyloxy-2,5-diaminobenzene, a compound represented by each of the following formulas (D-14) to (D-16), and a compound represented by the above formula (D-VI) At least one of the group consisting of 1,3-bis(3-aminopropyl)-tetramethyldioxane in the compound (hereinafter referred to as "other specific diamine (2)").

The diamine used in the synthesis of the polyamic acid used in the present invention preferably contains at least 5 mol% or more of at least one selected from the compounds represented by the above formulas (I) and (II) with respect to all diamines. More preferably, it contains 10 to 90 mol%, further preferably 20 to 80 mol%, and particularly preferably 30 to 50 mol%.

The diamine used in the synthesis of the polylysine used in the present invention preferably contains at least one selected from the group consisting of the compounds represented by the above formulas (I) and (II), and preferably further selected from the others described above. At least one of the group consisting of the specific diamine (1) and the specific diamine (2) preferably contains 10 to 90 mol% of these diamines, more preferably 20 to 80 mol%, based on the entire diamine. Further preferably, it contains 50 to 70 mol%.

The diamine used in the synthesis of the polyamic acid used in the present invention is particularly preferably any one of the following (1) or (2).

(1) at least one selected from the group consisting of the compounds represented by the above formulas (I) and (II) in the above ratio, and preferably contains 10 to 90 mol% of other specific diamines relative to all diamines (2) More preferably, it contains 20 to 80 mol%, and further preferably contains 50 to 70 mol%.

(2) at least one selected from the group consisting of the compounds represented by the above formulas (I) and (II) in the above ratio, and preferably containing 1 to 20 mol% of other specific diamines relative to all diamines (1) More preferably, it contains 5 to 10 mol%.

In the case of the above formula (2), it is preferred to contain at least one selected from the group consisting of the compounds represented by the above formulas (I) and (II), and other specific diamines (1) and other specific diamines (2). amine. As a content ratio thereof, at least one selected from the group consisting of the compounds represented by the above formulas (I) and (II) and the other specific diamines (1) each have the above ratio, and for the specific diamine (2), It is preferably 10 to 80 mol%, more preferably 20 to 70 mol%, based on the entire diamine.

<Synthesis of polylysine>

The polyamic acid used in the present invention can be synthesized by reacting a tetracarboxylic dianhydride as described above with a diamine.

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 1 equivalent of the amino group contained in the diamine and the acid anhydride group of the tetracarboxylic dianhydride. More 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 0.5 to 120 hours, more preferably 2 to 2 The reaction time was 10 hours.

Here, the organic solvent is not particularly limited as long as it is a solvent capable of dissolving the synthesized polylysine, and examples thereof include N-methyl-2-pyrrolidone and N,N-dimethylacetamide. Aprotic polar solvents such as N,N-dimethylformamide, dimethylhydrazine, γ-butyrolactone, tetramethylurea, hexamethylphosphonium triamine; m-methylphenol, xylenol , phenolic solvents such as phenol and halogenated phenol. The amount (a) of the organic solvent is preferably 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. Further, when an organic solvent is used in combination with the following poor solvent, the amount of the organic solvent is understood to mean the total amount of the organic solvent and the poor solvent.

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, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, ethylene glycol monomethyl ether, and lactic acid. Ethyl ester, butyl lactate, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, methyl methoxypropionate, ethoxy propyl Ethyl acetate, diethyl oxalate, diethyl malonate, diethyl ether, ethylene glycol methyl ether, ethylene glycol ether, ethylene glycol n-propyl ether, ethylene glycol isopropyl ether, ethylene glycol n-butyl ether, ethylene Alcohol 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 acetate, tetrahydrofuran, dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene, hexane, g Alkane, octane, benzene, toluene, xylene, isoamyl propionate, isoamyl isobutyrate, isoamyl ether, and the like.

In the synthesis of poly-proline, when the organic solvent is used in combination with a poor solvent, the use ratio of the poor solvent is preferably 20% by weight or less, more preferably 10% by weight based on the total amount of the organic solvent and the poor solvent. %the following.

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 may be obtained by separating the polyamic acid contained in the reaction solution and then supplying the liquid crystal alignment agent, or may be further purified by supplying the separated polyamic acid. Preparation of liquid crystal alignment agent. The separation of the polyamic acid can be carried out by adding the above 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 using an evaporator. Further, the poly-proline can be purified by performing the method of dissolving the polyamine 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 used in the present invention can be obtained by dehydrating a guanidine structure of polylysine as described above by dehydration ring closure. Here, it may be a fully ruthenium imide compound in which the proline structure of the polyamic acid has a dehydration ring closure, or a ruthenium iodide polymer in which a guanidine structure and a quinone ring may coexist. The ruthenium iodide ratio of the ruthenium iodide polymer used in the present invention is preferably 50% or more, more preferably 55 to 95%, particularly preferably 60 to 90%. Here, the "rhodium imidization ratio" means the total amount of the proline structure in the ruthenium iodide and the number of the quinone ring, and the ratio of the number of the quinone ring is expressed as a percentage. . At this time, a part of the quinone ring may also be an isoindole ring.

a dehydration ring closure of polylysine, which may be (i) by 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. 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. The reaction time is preferably from 1 to 120 hours, more preferably from 2 to 30 hours.

In the method of adding a dehydrating agent and a 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 preferably from 0.01 to 20 moles per 1 mole of the repeating unit of the polyglycolic acid. Further, as the dehydration ring-closure catalyst, a tertiary amine such as pyridine, trimethylpyridine, dimethylpyridine 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. In addition, examples of the organic solvent used in the dehydration ring-closure reaction include an organic solvent exemplified as a solvent used in the synthesis of polylysine. The reaction temperature of the dehydration ring closure reaction is preferably 0 to 180 ° C, more preferably 10 to 150 ° C, and the reaction time is preferably 0.5 to 30 hours, more preferably 2 to 10 hours.

The quinone imidized polymer obtained in the above method (i) may be directly supplied to a liquid crystal alignment agent, or may be obtained by refining the obtained quinone imidized polymer and then supplying the liquid crystal alignment agent. Further, in the above method (ii), a reaction solution containing a ruthenium iodide polymer is obtained. The reaction solution may be directly supplied to the liquid crystal alignment agent, or may be supplied from the reaction solution to remove the dehydrating agent and the dehydration ring-closing catalyst, and then supplied to the liquid crystal alignment agent. The ruthenium iodide polymer may be separated and supplied to the liquid crystal. The formulation of the alignment agent or the separation of the separated ruthenium-imiding polymer may be supplied to the 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 described above for the separation and purification method of polyglycine.

<End modified polymer>

Each of the polyamic acid and the ruthenium iodide polymer may be a terminal modified polymer having a molecular weight adjusted. Such a terminal-modified polymer can be synthesized by adding a suitable molecular weight modifier such as a monoanhydride, a monoamine compound or a monoisocyanate compound to the reaction system during the synthesis of the polyamic acid. Here, examples of the monoanhydride include maleic anhydride, phthalic anhydride, itaconic anhydride, n-decyl succinic anhydride, n-dodecyl succinic anhydride, n-tetradecyl succinic anhydride, n-hexadecyl group. Succinic anhydride and the like. Examples of the monoamine compound include aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-decylamine, n-decylamine, n-undecylamine, and n-xylylene. Alkylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecaneamine, n-octadecylamine, n-icosylamine, and the like. Examples of the monoisocyanate compound include phenyl isocyanate and 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.

<Solid viscosity of polymer>

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

The solution viscosity (mPa‧s) of the above polymer is a 10% by weight polymer solution formulated with a good solvent (for example, N-methyl-2-pyrrolidone, γ-butyrolactone, etc.) of the polymer. The value measured at 25 ° C using an E-type rotational viscometer.

<Other ingredients>

The liquid crystal alignment agent of the present invention contains at least one polymer selected from the group consisting of polylysine as described above and its ruthenium iodide polymer as an essential component, and otherwise, does not impair the effects of the present invention. Under the premise of the advantages, it may further contain other ingredients. Examples of such other components include other polymers, compounds having at least one epoxy group in the molecule (hereinafter referred to as "epoxy compounds"), and functional decane compounds.

The other polymer may, for example, be a polyfluorene obtained by reacting a polyorganosiloxane or a tetracarboxylic dianhydride with a diamine which does not contain any of the compounds represented by the above formulas (I) and (II). Aminic acid (hereinafter referred to as "other polyamic acid") and its quinone imidized polymer (hereinafter referred to as "other quinone imidized polymer"), polyglycolate, polyester, polyamine, A cellulose derivative, a polyacetal, a polystyrene derivative, a poly(styrene-phenylmaleimide) derivative, a poly(meth)acrylate, or the like. Among them, from the viewpoint of excellent varnish properties and electrical properties, other polyaminic acid or other quinone imidized polymers are preferred.

The tetracarboxylic dianhydride used for synthesizing other polyamines and other quinone imidized polymers is the same as exemplified as the tetracarboxylic dianhydride used for the synthesis of the above polyamic acid. The diamine used in the synthesis of other polyaminic acid and other quinone imidized polymers is the same as exemplified as other diamines which can be used in the synthesis of the above polyamic acid. In this case, it is preferable to contain 70 mol% or more of a diamine selected from at least one of the other specific diamines (1) and (2) with respect to all the diamines, and particularly preferably contain 90 mol% or more of a diamine. Other poly-proline and other ruthenium-based polymers, as the diamine, may be used as a poly-diamine in addition to the diamine which does not contain any of the compounds represented by the above formulas (I) and (II). The method described for the synthesis of proline and ruthenium iodide polymers is synthesized in the same manner. Among other polyaminic acids and other quinone imidized polymers, other polylysines are preferred.

The use ratio of the other polymer in the liquid crystal alignment agent of the present invention is a total amount of the polymer (refers to a reaction of a tetracarboxylic dianhydride with a diamine containing the compound represented by the above formula (I) or (II). The total amount of the polyaminic acid and its quinone imidized polymer and optionally other polymers, the same as below, is preferably 80% by weight or less, more preferably 60% by weight or less, still more preferably 40% by weight. %the following.

The epoxy group compound may be used from the viewpoint of further improving the adhesion of the liquid crystal alignment film formed of the liquid crystal alignment agent of the present invention to the surface of the substrate, and examples thereof include ethylene glycol diglycidyl ether and polyethylene glycol. Alcohol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, trishydroxyl Propane triglycidyl ether, glycerol diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, N,N,N',N'-tetraglycidyl-m-xylylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, N , N-diglycidyl-benzylamine, N,N-diglycidyl-aminomethylcyclohexane, and the like. The mixing ratio of these epoxy compounds is preferably 40 parts by weight or less, more preferably 0.1 to 30 parts by weight, based on 100 parts by total of the total amount of the polymer.

The functional decane compound may, for example, be 3-aminopropyltrimethoxydecane, 3-aminopropyltriethoxydecane, 2-aminopropyltrimethoxydecane or 2-aminopropyltriethoxy. Decane, N-(2-aminoethyl)-3-aminopropyltrimethoxydecane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxydecane, 3-ureidopropyl Trimethoxy decane, 3-ureidopropyltriethoxy decane, 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-diazadecyl acetate, 9-triethoxydecane Methyl-3,6-diazaindolyl acetate, methyl 9-trimethoxydecyl-3,6-diazadecanoate, 9-triethoxydecyl-3,6-diaza Methyl sulfonate, N-benzyl-3-aminopropyltrimethoxydecane, N-benzyl-3-aminopropyltriethoxydecane, N-phenyl-3-aminopropane Trimethoxydecane, N-phenyl-3-aminopropyltriethoxydecane, glycidoxymethyltrimethoxydecane, glycidoxymethyltriethoxydecane, 2-epoxy Propoxyethyltrimethoxydecane, 2-glycidoxyethyltriethoxydecane, 3-glycidoxypropyltrimethoxydecane, 3-glycidoxypropyltriethyl Oxydecane, etc.

The mixing ratio of these functional decane compounds 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 at least one polymer selected from the group consisting of polylysine as described above and its quinone imidized polymer, and other components optionally added as needed, preferably dissolved. Contained in an organic solvent.

As the above polymer, only polyacrylic acid may be used, or only a ruthenium iodide polymer may be used, or both a polyamic acid and a ruthenium iodide polymer may be used together. The polymer contained in the liquid crystal alignment agent of the present invention is preferably a ruthenium iodide polymer or a combination of a polyamic acid and a ruthenium iodide polymer. Here, the amount of the proline structure of the polyamic acid contained in the liquid crystal alignment agent and the total amount of the proline structure and the number of the quinone ring of the ruthenium iodide polymer, The ratio of the number of quinone rings possessed by the aminated polymer (hereinafter referred to as "average oxime imidization ratio". When the liquid crystal alignment agent of the present invention contains other polyamido acids and other quinone imidized polymers, the average The ruthenium imidization ratio is understood to be a value calculated by including them, and is preferably 40% or more, more preferably 45 to 90%, particularly preferably 50 to 80%.

The organic solvent which can be used for the liquid crystal alignment agent of the present invention may, for example, be a solvent exemplified above as a solvent used in the synthesis reaction of polyglycine. Further, a solvent exemplified as a poor solvent which can be used in combination in the synthesis reaction of polyglycine can be appropriately selected.

Specific examples of the organic solvent which may be contained in the liquid crystal alignment agent of the present invention include N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactone, and N,N-dimethylformamidine. Amine, N,N-dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, Ethyl ethoxypropionate, ethylene glycol methyl ether, ethylene glycol 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 Acetate, isoamyl propionate, isoamyl isobutyrate, diisobutyl ketone, isoamyl ether, ethylene carbonate, propylene carbonate, and the like. They may be used singly or in combination of two or more. A particularly preferable solvent composition is a composition obtained by combining the above solvents, and is a composition in which the polymer does not precipitate from the alignment agent and the surface tension of the alignment agent falls within a range of 25 to 40 mN/m.

The solid content concentration of the liquid crystal alignment agent of the present invention (the ratio of the total weight of the components other than the solvent contained in the liquid crystal alignment agent to the total weight of the liquid crystal alignment agent) is selected in consideration of viscosity, volatility, etc., preferably 1 to 10 parts by weight. %. That is, the liquid crystal alignment agent of the present invention forms a coating film as a liquid crystal alignment film by being applied to the surface of the substrate and removing the solvent, and when the solid content concentration is less than 1% by weight, the thickness of the coating film is too small. When it is difficult to obtain a good liquid crystal alignment film, when the solid content concentration exceeds 10% by weight, the thickness of the coating film is too thick and it is difficult to obtain a good liquid crystal alignment film, and the viscosity of the liquid crystal alignment agent increases, resulting in an increase in viscosity. The coating performance is deteriorated.

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 alignment film formed by the liquid crystal alignment agent of the present invention can exhibit a high voltage holding ratio and good afterimage performance as much as possible when used as a vertical alignment type liquid crystal alignment film.

The liquid crystal display element of the present invention can be produced, for example, by the following method.

(1) The liquid crystal alignment agent of the present invention is applied onto one surface of a substrate provided with a patterned transparent conductive film by an appropriate coating method such as a roll coating method, a spin coating method, a printing method, or an inkjet method, and then The coating film is formed by heating the coated surface. Here, as the substrate, for example, glass such as float glass or soda lime glass; polyethylene terephthalate, polybutylene terephthalate, polyether oxime, polycarbonate, alicyclic poly A transparent substrate made of plastic such as olefin. As the transparent conductive film provided on one surface of the substrate, for example, 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. . These transparent conductive film patterns may be formed by photolithography or a method of using a photomask in advance when forming a transparent conductive film. 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, a functional decane compound, a functional titanium compound or the like may be applied to the surface of the substrate in advance. After the application of the liquid crystal alignment agent, in order to prevent the coating agent liquid from sagging or the like, it is preferred to perform preheating (prebaking). The prebaking temperature is preferably from 30 to 200 ° C, more preferably from 40 to 150 ° C, and particularly preferably from 40 to 100 ° C. The prebaking time is preferably from 0.25 to 10 minutes, more preferably from 0.5 to 5 minutes. After the solvent is completely removed, it is preferred to further carry out the heating (post-baking) step. The post-baking temperature is preferably from 80 to 300 ° C, more preferably from 120 to 250 ° C. The post-baking time is preferably from 5 to 200 minutes, more preferably from 10 to 100 minutes. The liquid crystal alignment agent of the present invention forms a coating film as an alignment film by coating after removing the organic solvent as described above, and when the polymer contained in the liquid crystal alignment agent of the present invention is a polyamic acid or a quinone imine In the case of a quinone imidized polymer having a ring structure and a proline structure, it is also possible to carry out a dehydration ring-closure reaction by further heating after forming a coating film to form a further yttrium-imided coating film.

The thickness of the coating film formed here is preferably 0.001 to 1 μm, more preferably 0.005 to 0.5 μm.

(2) The coating film formed as described above may be used as a vertical alignment type liquid crystal alignment film as it is, or may be optionally coated with a roll of a suitable fiber such as nylon, rayon, cotton or the like. After the rubbing treatment in a certain direction, it is used as a liquid crystal alignment film. Furthermore, the coating film for the liquid crystal alignment film shown in the patent document 6 (JP-A-H06-222366) or the patent document 7 (JP-A-6-281937) is applied to the liquid crystal alignment film. When a part of the surface of the liquid crystal alignment film is formed on the surface of the liquid crystal alignment film, a part of the surface of the liquid crystal alignment film is formed by a method of irradiating the ultraviolet ray to change the pretilt angle of a part of the liquid crystal alignment film, and the method of forming a protective film on the surface of the liquid crystal alignment film as shown in Japanese Laid-Open Patent Publication No. Hei No. 5-105044 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, and the field of view performance of the obtained liquid crystal display element can be improved. When the coating film surface is polished, it can be washed as needed.

(3) Two substrates on which the liquid crystal alignment film was formed as described above were prefabricated, and liquid crystal cells were produced by arranging liquid crystal between the two substrates. For the production of the liquid crystal cell, for example, the following two methods can be mentioned.

The first method is a previously known method. First, the two substrates are opposed to each other through a gap (cell gap), and the respective liquid crystal alignment films are opposed to each other, and the peripheral portions of the two substrates are bonded together with a sealant to the interstitial space surrounded by the substrate surface and the sealant. After filling the liquid crystal, the liquid crystal cell can be obtained by closing the injection hole.

The second method is called the ODF (One Drop Fill) method. For example, an ultraviolet curable sealant material is applied to a predetermined portion of one of the two substrates on which the liquid crystal alignment film is formed, and the liquid crystal is dropped on the liquid crystal alignment film surface, and then the other substrate is bonded to the liquid crystal alignment film. Opposite, and then the entire surface of the substrate is irradiated with ultraviolet rays to cure the sealant to obtain a liquid crystal cell. The liquid crystal alignment agent of the present invention has an advantage that a liquid crystal display element which does not cause liquid crystal alignment unevenness due to liquid crystal drop marks can be obtained even when a VA type liquid crystal display element is produced by the ODF method. This advantage is particularly remarkable when the liquid crystal alignment agent of the present invention comprises a diamine-synthesized polymer containing a specific diamine (1) in addition to at least one of the compounds represented by the above formulas (I) and (II). .

In the case of using any of the above first and second methods, it is necessary to subsequently heat the liquid crystal cell to a temperature at which the liquid crystal used is in an isotropic phase, and then slowly cool to room temperature to remove the liquid alignment during liquid crystal filling. .

Then, the liquid crystal display element of the present invention can be obtained by laminating a polarizing plate on the outer surface of the liquid crystal cell.

Here, as the sealant, for example, an epoxy resin containing an alumina ball as a curing agent and a spacer, 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 base liquid crystal, an azo 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 or the like. Further, in these liquid crystals, cholesteric liquid crystal such as cholesteryl cholesteryl, cholesteryl phthalate or cholesteryl carbonate may be further added; and the trade names "C-15" and "CB-15" (manufactured by MERCK Co., Ltd.) may be further added. Used as a chiral agent for sale.

The polarizing plate to be bonded to the outer surface of the liquid crystal may be a polarizing plate 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, or H. A polarizing plate made of the film itself.

[Examples]

Hereinafter, the present invention will be more specifically described by way of examples, but the invention is not limited to the examples. The solution viscosity of the polymer and the ruthenium imidization ratio of the ruthenium iodide polymer in the following synthesis examples were evaluated by the following methods.

[Solid viscosity of polymer]

The solution viscosity of the polymer is a value measured at 25 ° C for the polymer solution indicated in each synthesis example using an E-type viscometer.

[醯imine ratio of ruthenium iodide polymer]

The ruthenium iodide polymer was dried under reduced pressure at room temperature, and then dissolved in deuterated dimethyl hydrazine, and ¹ H-NMR was measured at room temperature using tetramethyl decane as a reference. The formula shown in the formula (i) is obtained.

Yttrium imidation rate (%) = (1-A1/A2 × α) × 100 (i)

A1: peak area originating from the NH matrix near 10 ppm

A2: Peak area derived from other protons

α: ratio of the number of other protons relative to one NH matrix in the polymer precursor (polyglycolic acid).

<Synthesis of a diamine represented by the above formula (I) or (II)>

In each of the following synthesis examples, the following synthesis scale was repeated as needed to secure a necessary amount of the product in the subsequent synthesis examples.

Synthesis Example 1 (Synthesis of 1-(2,4-diaminophenoxy)-4-(4-(4-n-pentylcyclohexyl)cyclohexyl)benzene)

Synthesis of 1-(2,4-diaminophenoxy)-4-(4-(4-n-pentylcyclohexyl)cyclohexyl)benzene according to the following Scheme 1 (hereinafter, also referred to as "diamine A" ).

20.3 g (0.1 mol) of 1-chloro-2,4-dinitrobenzene and 32.9 g of 4-(4-(4-n-pentylcyclohexyl)cyclohexyl)phenol (0.1 mol) under nitrogen atmosphere 41.4 g (0.3 mol) of potassium carbonate was dissolved in 500 ml of dimethylformamide and allowed to react at room temperature for 6 hours. After adding 500 ml of distilled water to the reaction solution and thoroughly stirring, it was extracted with 500 ml of chloroform, and the obtained organic layer was extracted and washed with distilled water. After the washed organic layer was dehydrated with magnesium sulfate, the solvent was removed using a rotary evaporator to give 47.0 g of 1-(2,4-dinitrophenoxy)-4-(4-(4-n-pentylcyclohexyl) Cyclohexyl) benzene.

Then, under a nitrogen atmosphere, to the above 1-(2,4-dinitrophenoxy)-4-(4-(4-n-pentylcyclohexyl)cyclohexyl)benzene 24.8 g (0.05 mol) Palladium/carbon (Pd/C) 18.2 g and 300 ml of tetrahydrofuran were added, and the mixture was stirred at 70 ° C for 1 hour. To the mixture was added 30 ml of hydrazine monohydrate, and the mixture was stirred at 80 ° C for 3 hours under nitrogen to carry out a reaction. After completion of the reaction, the catalyst was filtered off, and the filtrate was concentrated, and then dissolved in 300 ml of chloroform, and the organic solvent layer was extracted and washed with distilled water. The organic solvent layer was dehydrated with magnesium sulfate and concentrated on a rotary evaporator to give a crude product of diamine A. The crude product was purified by column chromatography, and then solvent was removed to give 18.1 g of diamine A.

Synthesis Example 2 (Synthesis of 4-(4-(4-n-pentylcyclohexyl)cyclohexyl)phenyl 3,5-diaminobenzoate)

4-(4-(4-n-pentylcyclohexyl)cyclohexyl)phenyl 3,5-diaminobenzoate (hereinafter also referred to as "diamine B") was synthesized according to the following Scheme 2.

Mixing 42.9 g (0.1 mol) of 4-(4-(4-n-pentylcyclohexyl)cyclohexyl)phenol, 10.6 g (0.105 mol) of triethylamine and 300 ml of tetrahydrofuran under a nitrogen atmosphere, at 0 Dissolve and dissolve at °C. To the solution, a mixed solution of 21.8 g (0.105 mol) of 3,5-dinitrobenzimid chloride and 100 ml of tetrahydrofuran was added dropwise thereto over 30 minutes, and the mixture was stirred at room temperature for 3 hours to carry out a reaction. After the precipitated salt was filtered off, the filtrate was concentrated, and then dissolved in 300 ml of chloroform, and extracted with distilled water. The organic layer was dried over magnesium sulfate and concentrated using a rotary evaporator. The crude product thus obtained was purified by column chromatography, and then solvent was evaporated to give 51.2 g of 4-(4-(4-n-pentylcyclohexyl)cyclohexyl)phenyl 3,5-dinitrobenzoate.

Then, to the above-mentioned 3,5-dinitrobenzoic acid 4-(4-(4-n-pentylcyclohexyl)cyclohexyl)phenyl ester 26.1 g (0.05 mol), tin chloride was added under a nitrogen atmosphere. 112.8 g (0.5 mol) of dihydrate and 400 ml of ethyl acetate were heated under reflux for 3 hours to carry out a reaction. After completion of the reaction, the reaction solution was mixed with 400 ml of a saturated potassium fluoride aqueous solution, stirred well, and then separated, and the obtained organic layer was extracted and washed with distilled water. Then, the organic layer was dried over magnesium sulfate, concentrated on a rotary evaporator, and purified by column chromatography, and then solvent was evaporated to afford 17.4 g of diamine B.

Synthesis Example 3

The diamine C represented by the following formula is synthesized by the method described in the patent document 2 (JP-A-H09-278724).

Synthesis Example 4

The compound represented by the above formula (D-5) (hereinafter referred to as "compound (D-5)") is synthesized by the method described in JP-A-4-281427.

<Synthesis of ruthenium iodide polymer> Synthesis Example 5

3,5,6-tricarboxy-2-carboxymethylnorbornane-2:3,5:6-dianhydride 12.5 g (0.05 mol) as tetracarboxylic dianhydride and p-benzene as diamine 3.2 g (0.03 mol) of diamine and 8.7 g (0.02 mol) of diamine A synthesized in the above Synthesis Example 1 were dissolved in 98 g of N-methyl-2-pyrrolidone (NMP), and reacted at 60 ° C for 6 hours. . A small amount of the obtained polyaminic acid solution was taken, and NMP was added to prepare a solution having a polyglycine concentration of 10% by weight, and the measured solution viscosity was 51 mPa·s.

Then, 120 g of NMP was added to the obtained polyamic acid solution, and 20 g of pyridine and 20 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 (by the solvent replacement operation, the pyridine and acetic anhydride used in the dehydration ring closure reaction are removed to the outside of the system. The same applies hereinafter). About 170 g of a solution containing a ruthenium iodide polymer (A-1) having a ruthenium iodide ratio of about 90%. This solution was prepared into a γ-butyrolactone solution having a polymer concentration of 10% by weight, and the measured solution viscosity was 62 mPa·s.

Synthesis Example 6

3,5,6-tricarboxy-2-carboxymethylnorbornane-2:3,5:6-dianhydride 12.5 g (0.05 mol) as tetracarboxylic dianhydride and p-benzene as diamine Diamine 3.2 g (0.03 mol) and diamine B 9.2 g (0.02 mol) were dissolved in 98 g of NMP and reacted at 60 ° C for 6 hours. A small amount of the obtained polyaminic acid solution was taken, and NMP was added to prepare a solution having a polyglycine concentration of 10% by weight, and the measured solution viscosity was 61 mPa·s.

Then, 120 g of NMP was added to the obtained polyamic acid solution, and 20 g of pyridine and 20 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, a solvent of the system is replaced with a new γ-butyrolactone to obtain about 160 g of a solution containing a ruthenium iodide polymer (A-2) having a ruthenium iodide ratio of about 90%. . This solution was prepared into a γ-butyrolactone solution having a polymer concentration of 10% by weight, and the measured solution viscosity was 71 mPa·s.

Synthesis Example 7

11 g (0.05 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as tetracarboxylic dianhydride, and 3.2 g (0.03 mol) of p-phenylenediamine as diamine and 8.7 g of diamine A (0.02 mol) was dissolved in 93 g of NMP and reacted at 60 ° C for 6 hours. A small amount of the obtained polyaminic acid solution was taken, and NMP was added to prepare a solution having a polyglycine concentration of 10% by weight, and the measured solution viscosity was 48 mPa·s.

Then, 120 g of N-methyl-2-pyrrolidone was added to the obtained polyamic acid solution, and 20 g of pyridine and 20 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, a solvent of the system is replaced with a new γ-butyrolactone to obtain about 160 g of a solution containing a ruthenium iodide polymer (A-3) having a ruthenium iodide ratio of about 90%. . This solution was prepared into a γ-butyrolactone solution having a polymer concentration of 10% by weight, and the measured solution viscosity was 58 mPa·s.

Synthesis Example 8

3,5,6-tricarboxy-2-carboxymethylnorbornane-2:3,5:6-dianhydride as tetracarboxylic dianhydride 12.5 g (0.05 mol), and as a diamine Phenyldiamine 3.2 g (0.03 mol), diamine A 6.5 g (0.015 mol) and compound (D-5) 2.6 g (0.005 mol) were dissolved in 100 g of NMP and reacted at 60 ° C for 6 hours. A small amount of the obtained polyaminic acid solution was taken, and NMP was added to prepare a solution having a polyglycine concentration of 10% by weight, and the measured solution viscosity was 47 mPa·s.

Then, 124 g of NMP was added to the obtained polyamic acid solution, and 20 g of pyridine and 20 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, a solvent of the system is replaced with a new γ-butyrolactone to obtain about 180 g of a solution containing a ruthenium iodide polymer (A-4) having a ruthenium iodide ratio of about 90%. . This solution was prepared into a γ-butyrolactone solution having a polymer concentration of 10% by weight, and the measured solution viscosity was 57 mPa·s.

Synthesis Example 9

12.5 g (0.05 mol) of 3,5,6-tricarboxy-2-carboxymethylnorbornane-2:3,5:6-dianhydride as tetracarboxylic dianhydride as p-diphenylbenzene Diamine 3.2 g (0.03 mol), diamine B 6.9 g (0.015 mol) and compound (D-5) 2.6 g (0.005 mol) were dissolved in 101 g of NMP and reacted at 60 ° C for 6 hours. A small amount of the obtained polyaminic acid solution was taken, and NMP was added to prepare a solution having a polyglycine concentration of 10% by weight, and the measured solution viscosity was 46 mPa·s.

Then, 126 g of NMP was added to the obtained polyamic acid solution, and 20 g of pyridine and 20 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, a solvent of the system was replaced with a new γ-butyrolactone to obtain about 185 g of a solution containing a ruthenium iodide polymer (A-5) having a ruthenium iodide ratio of about 90%. . This solution was prepared into a γ-butyrolactone solution having a polymer concentration of 10% by weight, and the measured solution viscosity was 56 mPa·s.

Synthesis Example 10

11.2 g (0.05 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as tetracarboxylic dianhydride, 3.2 g (0.03 mol) of p-phenylenediamine as diamine, and diamine A 6.5 g (0.015 mol) and compound (D-5) 2.6 g (0.005 mol) were dissolved in 94 g of NMP and reacted at 60 ° C for 6 hours. A small amount of the obtained polyaminic acid solution was taken, and NMP was added to prepare a solution having a polyglycine concentration of 10% by weight, and the measured solution viscosity was 45 mPa·s.

Then, 118 g of NMP was added to the obtained polyaminic acid solution, and 20 g of pyridine and 20 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, a solvent of the system is replaced with a new γ-butyrolactone to obtain about 180 g of a solution containing a ruthenium iodide polymer (A-6) having a ruthenium iodide ratio of about 90%. . This solution was prepared into a γ-butyrolactone solution having a polymer concentration of 10% by weight, and the measured solution viscosity was 58 mPa·s.

Synthesis Example 11

3,5,6-tricarboxy-2-carboxymethylnorbornane-2:3,5:6-dianhydride as tetracarboxylic dianhydride 12.5 g (0.05 mol), and as a diamine Phenyldiamine 3.2 g (0.03 mol), diamine A 6.5 g (0.015 mol) and compound (D-5) 2.6 g (0.005 mol) were dissolved in 100 g of NMP and reacted at 60 ° C for 6 hours. A small amount of the obtained polyaminic acid solution was taken, and NMP was added to prepare a solution having a polyglycine concentration of 10% by weight, and the measured solution viscosity was 47 mPa·s.

Then, 1243 g of NMP was added to the obtained polyamic acid solution, and 4 g of pyridine and 5.1 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, a solvent of the system was replaced with a new γ-butyrolactone to obtain about 170 g of a solution containing a ruthenium iodide polymer (A-7) having a ruthenium iodide ratio of about 45%. . This solution was prepared into a γ-butyrolactone solution having a polymer concentration of 10% by weight, and the measured solution viscosity was 63 mPa·s.

<Synthesis of other polymers> (Synthesis of other quinone imidized polymers) Synthesis Example 12

3,5,6-tricarboxy-2-carboxymethylnorbornane-2:3,5:6-dianhydride 125 g (0.5 mol) as tetracarboxylic dianhydride, p-phenylene as diamine Amine 32 g (0.3 mol) and diamine C 70 g (0.2 mol) were dissolved in 910 g of NMP and reacted at 60 ° C for 6 hours. A small amount of the obtained polyaminic acid solution was taken, and NMP was added to prepare a solution having a polyglycine concentration of 10% by weight, and the solution viscosity was determined to be 55 mPa·s.

Then, 1100 g of NMP was added to the obtained polyamic acid solution, and 200 g of pyridine and 200 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, a solvent of the system is replaced with a new γ-butyrolactone to obtain about 1600 g of a solution containing a ruthenium iodide polymer (A-8) having a ruthenium iodide ratio of about 90%. . This solution was prepared into a γ-butyrolactone solution having a polymer concentration of 10% by weight, and the measured solution viscosity was 65 mPa·s.

Synthesis Example 13

12.5 g (0.05 mol) of 3,5,6-tricarboxy-2-carboxymethylnorbornane-2:3,5:6-dianhydride as tetracarboxylic dianhydride, and as a diamine 4.3 g (0.04 mol) of phenylenediamine and 5.2 g (0.01 mol) of compound (D-5) were dissolved in 88 g of NMP and reacted at 60 ° C for 6 hours. A small amount of the obtained polyaminic acid solution was taken, and NMP was added to prepare a solution having a polyglycine concentration of 10% by weight, and the measured solution viscosity was 45 mPa·s.

Then, 110 g of NMP was added to the obtained polyamic acid solution, and 20 g of pyridine and 20 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, a solvent of the system is replaced with a new γ-butyrolactone to obtain about 170 g of a solution containing a ruthenium iodide polymer (A-9) having a ruthenium iodide ratio of about 90%. . This solution was prepared into a γ-butyrolactone solution having a polymer concentration of 10% by weight, and the measured solution viscosity was 55 mPa·s.

(Synthesis of other polylysines) Synthesis Example 14

55 g (0.25 mol) of pyromellitic dianhydride as tetracarboxylic dianhydride and 49 g (0.25 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride as p-diphenyl benzene The diamine 54 g (0.5 mol) was dissolved in 630 g of NMP and reacted at 60 ° C for 6 hours. About 1200 g of a solution containing 20% by weight of polyamic acid (B-1) was obtained. A small amount of the polyaminic acid solution was taken, and NMP was added to prepare a solution having a polyglycine concentration of 10% by weight, and the measured solution viscosity was 70 mPa·s.

Example 1 <Preparation of liquid crystal alignment agent>

The solution of the ruthenium-imidized polymer (A-1) obtained in the above Synthesis Example 5 and the solution containing the poly-proline (B-1) obtained in the above Example 14 were used in each solution. The weight ratio of the polymer contained is (A-1): (B-1)=80:20, and γ-butyrolactone, NMP and butyl cellosolve are added thereto, and the solvent composition is γ-butane. Ester: NMP: butyl cellosolve = 71:17:12 (by weight), a solution having a solid content concentration of 2.5% by weight. This solution was filtered through a filter having a pore size of 1 μm to prepare a liquid crystal alignment agent (S-1). The average oxime imidization ratio of the polymer contained in the liquid crystal alignment agent is shown in Table 1.

<Manufacture of Vertical Alignment Type Liquid Crystal Cell>

The liquid crystal alignment agent (S-1) was applied onto the transparent electrode surface of a glass substrate with a transparent electrode made of an ITO film by spin coating, and prebaked on a hot plate at 80 ° C for 1 minute and then at 200 ° C. The hot plate was post-baked for 10 minutes to form a coating film (liquid crystal alignment film) having an average thickness of 60 nm. This operation was repeated to produce a pair of (two pieces) substrates having a liquid crystal alignment film on the surface of the transparent electrode.

On each of the outer edges of the pair of liquid crystal alignment films having a liquid crystal alignment film, an epoxy resin adhesive having an alumina ball of 5.5 μm is applied, and the liquid crystal alignment film faces are relatively overlapped. And press, and then the adhesive is cured. Next, a negative liquid crystal (MLC-6608, manufactured by MERCK Co., Ltd.) was filled between the pair of substrates through the liquid crystal injection port, and then the liquid crystal injection port was sealed with an acrylic photocurable adhesive to produce a vertical alignment type liquid crystal cell. The liquid crystal cell was evaluated for voltage holding ratio and afterimage performance as follows. The evaluation results are shown in Table 1.

<Evaluation of Voltage Retention Rate>

A voltage of 1 V was applied to the above-mentioned vertical alignment type liquid crystal cell at 65 ° C for a time span of 167 msec, and the application time was 60 μsec, and then the voltage holding ratio from the voltage release to 167 msec was measured. The measuring device used was VHR-1 manufactured by TOYO Corporation.

<Evaluation of afterimage performance>

A vertical alignment type liquid crystal cell was produced in the same manner as in the above-mentioned <manufacture of a vertical alignment type liquid crystal cell> except that a glass substrate having two ITO transparent electrodes having the pattern shown in Fig. 1 was used as the substrate.

In the environment of 40 to 50 ° C, while the backlight was irradiated to the liquid crystal cell, 6.0 V was applied to the electrode A, and a DC voltage of 0.5 V for 168 hours was applied to the electrode B. After the stress was released, a DC voltage of 0.1 to 5.0 V was applied to the electrodes A and B at a gradient of 0.1 V, and the afterimage performance was judged based on the difference in luminance between the electrodes A and B at each voltage. When the luminance difference is not identified, the afterimage performance is judged as "excellent", and when the luminance difference is small, the afterimage performance is judged as "good", and when the luminance difference is large, the afterimage performance is judged as "poor".

Examples 2 to 12 and Comparative Examples 1 to 3

Liquid crystal alignment agents (S-2) to (S-12) and (R-1) to (R-3) were prepared in the same manner as in Example 1 except that the polymer compositions listed in Table 1 were used to produce liquid crystals. Cell and evaluate. The evaluation results are shown in Table 1.

Further, the numerical values in parentheses after the polymer species name in Table 1 are the amounts (parts by weight) of the polymer contained in the polymer solution used, and the polyaminic acid solutions were not used in Examples 9 to 11 and Comparative Example 3. .

Example 13 <Evaluation of liquid crystal alignment unevenness performance>

The liquid crystal alignment agent (S-6) prepared in the above Example 6 was applied onto the transparent electrode surface of the glass substrate with the transparent electrode made of ITO film by spin coating, and prebaked on a hot plate at 80 ° C for 1 minute. Thereafter, it was post-baked on a hot plate at 200 ° C for 10 minutes to form a coating film (liquid crystal alignment film) having an average thickness of 60 nm. This operation was repeated to produce a pair of (two pieces) substrates having a liquid crystal alignment film on the surface of the transparent electrode.

On the liquid crystal alignment film surface of one of the substrates having the liquid crystal alignment film produced above, 5 μl of ultrapure water water droplets were dropped from a height of 5 mm by a micropipette, and naturally dried at room temperature as it was.

A vertical alignment type liquid crystal cell was produced in the same manner as in the above-described first embodiment, except that a pair of substrates including a substrate having an impact on the liquid crystal alignment film surface by droplet dropping as described above was used.

When a rectangular wave of 6.0 V (peak-to-peak) and 30 Hz was applied to the liquid crystal cell at room temperature, and observation under a crossed Nicol prism, no ultrapure water droplets were observed as uneven alignment of the liquid crystal. When the liquid crystal alignment unevenness performance was evaluated as "excellent", when fine droplet marks were observed, the liquid crystal alignment unevenness performance was evaluated as "good", and when the drip marks were clearly observed, the liquid crystal alignment unevenness performance was evaluated as " bad". The results are shown in Table 2.

Among them, the dropping of the above-mentioned ultrapure water droplets is an alternative evaluation for investigating the impact of the impact of liquid crystal dropping in the ODF step.

Examples 14 to 19 and Comparative Examples 4 and 5

A vertical alignment type liquid crystal cell was produced using a pair of substrates including a substrate having an impact on the liquid crystal alignment film surface by ultrapure water drop, in the same manner as in the above-described Example 13, except that the liquid crystal alignment agents were used as listed in Table 2, respectively. The evaluation of the liquid crystal alignment unevenness performance was performed. The results are shown in Table 2.

Fig. 1 is a schematic view showing the structure of a transparent electrode for evaluation of afterimage performance.

Claims (6)

A liquid crystal alignment agent characterized by comprising at least one polymer selected from the group consisting of polylysine and a quinone imidized polymer thereof, which reacts a tetracarboxylic dianhydride with a diamine Further, the diamine contains a compound represented by the following formula (I), and further contains 10 to 90 mol% relative to all diamines and is selected from the following formula (DI) and the following formula (D-II). At least one of the compounds represented by each, In the above formula, n1 is each independently an integer of 1-8; 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 valence organic group, R ⁶ represents an alkyl group having 1 to 4 carbon atoms, a1 represents an integer of 0 to 3, and in the formula (D-II), X ² each represents a group selected from -O-, -COO-, - a divalent organic group of OCO-, -NHCO-, -CONH-, and -CO-, R ⁷ represents a divalent organic group having a steroid skeleton, and R ⁸ each represents an alkyl group having 1 to 4 carbon atoms. A2 each represents an integer from 0 to 3. The liquid crystal alignment agent of claim 1, wherein the tetracarboxylic dianhydride Contains 3,5,6-tricarboxy-2-carboxymethylnorbornane-2:3,5:6-dianhydride. The liquid crystal alignment agent of claim 1 or 2, further comprising at least one polymer selected from the group consisting of polylysine and a quinone imidized polymer thereof, the polyamic acid system The carboxylic acid dianhydride is produced by reacting a diamine which does not contain any of the compounds represented by the above formula (I) and the following formula (II), The liquid crystal alignment agent of claim 1 or 2, wherein the polyamine acid contained in the liquid crystal alignment agent has a proline structure and the proline acid possessed by the ruthenium iodide polymer The combined amount of the number of structures and the number of the quinone ring, the amount ratio of the quinone imine ring possessed by the ruthenium iodide polymer is 40% or more. A liquid crystal alignment agent according to claim 1 or 2, which is characterized in that it is used for forming a vertical alignment type liquid crystal alignment film. A liquid crystal display element characterized by having a liquid crystal alignment film formed of the liquid crystal alignment agent according to any one of claims 1 to 5.