TWI461460B - Liquid aligning agent liquid crystal aligning film and liquid crystal display element - Google Patents

Description

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

The present invention relates to a liquid crystal alignment agent, a liquid crystal alignment film, and a liquid crystal display element. More specifically, it relates to a liquid crystal alignment agent capable of forming a liquid crystal alignment film having good liquid crystal alignment, exhibiting high voltage holding ratio, afterimage performance, and burn-in performance, and display performance of the liquid crystal alignment film. Excellent 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 widely known, and a liquid crystal alignment film is formed on a surface of a substrate on which a transparent conductive film is provided, as a substrate for a liquid crystal display element. Two substrates are disposed opposite to each other, and a nematic liquid crystal layer having positive dielectric anisotropy is formed in the gap to form a unit cell of the sandwich structure, and the long axis of the liquid crystal molecules is continuous from one substrate to the other substrate Twisted 90 degrees. In addition, STN (Super Twisted Nematic) liquid crystal display elements and IPS (in-plane switching) type liquid crystal display elements with higher contrast ratio than TN liquid crystal display elements have been developed, and viewing angle dependence has been developed. An OCB (Optically Compensatory Bend) type liquid crystal display element which is excellent in high-speed response of a video picture, and a VA (Vertical Alignment) type liquid crystal display element which uses a nematic liquid crystal having negative dielectric anisotropy.

Among these liquid crystal display elements, a liquid crystal alignment film made of an organic film such as polyimine, polyamine or polyester which aligns liquid crystal molecules is used. In particular, polyimine is used in many liquid crystal display elements because of its excellent heat resistance, affinity with liquid crystals, mechanical strength, and the like. A liquid crystal alignment film made of polyimine, which can be applied to a substrate by a solution of a polyimine precursor precursor polyamine or a soluble polyimine dissolved in an organic solvent. A coating film is formed and formed by grinding as needed.

Heretofore, as one of the problems of the liquid crystal display element, it is exemplified that an afterimage (so-called burn-in) can be observed when the cumulative driving time is long. In order to improve this afterimage phenomenon, some experiments have been carried out before. Almost all of them focus on the relationship between the uneven distribution and the accumulation (residual DC voltage) of the DC voltage component applied when "burning the screen" and driving the liquid crystal display element, and the "burning screen" is improved by reducing the residual DC voltage. For example, in Patent Document 1, it is considered that A liquid crystal alignment film made of a specific polyamine synthesized by a specific diamine structure of a chrome structure can effectively reduce the residual DC voltage, and attempts to improve burn-in thereby. However, in the liquid crystal alignment film of Patent Document 1, in the embodiment, the effect of improving the afterimage is not sufficiently verified, and display defects other than the occurrence of afterimage in the liquid crystal display element are not obtained, for example, based on the heterogeneity of the liquid crystal alignment. The resulting display unevenness is considered.

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2001-97969

[Patent Document 2] Japanese Patent Laid-Open No. Hei 6-222366

[Patent Document 3] Japanese Patent Laid-Open No. Hei 6-281937

[Patent Document 4] Japanese Patent Laid-Open No. Hei 5-170044

The present invention has been made in view of the above circumstances, and an object thereof is to provide a liquid crystal alignment agent capable of forming a liquid crystal alignment film having excellent liquid crystal alignment properties and exhibiting high voltage holding ratio and excellent afterimage performance.

Another object of the present invention is to provide a liquid crystal display element excellent in afterimage performance and burn-in performance.

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

According to the present invention, the above objects and advantages of the present invention, first, achieved by a liquid crystal alignment agent comprising at least one selected from the group consisting of polylysine and a ruthenium iodide polymer thereof The amine acid is obtained by reacting a tetracarboxylic dianhydride with a diamine containing a compound represented by the following formula (1).

(In the formula (1), X is a divalent organic group containing an aromatic ring or -O-*, -S-*, -SO ₂ -*, -NH-*, -COO-*, -OCO-*, -NHCO-*, -CONH-*, -CO-*, -CH ₂ O-* (where the above connection key with "*" is located One side of the fluorene structure), a methylene group or an alkyl group having 2 to 8 carbon atoms, and each Y is -O-*, -S-*, -SO ₂ -*, -NH-*, -COO-* , -OCO-*, -NHCO-*, -CONH-*, -CO-*, (wherein the above linkage with "*" is bonded to the amine phenyl group), methylene or carbon number is 2 The alkyl group of ~8, the two Ys may be the same or different, and each of R ^I , R ^II and R ^III is a hydrogen atom or a monovalent organic group).

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

The liquid crystal alignment agent of the present invention comprises at least one selected from the group consisting of polylysine and a quinone imidized polymer thereof, wherein the polycarboxylic acid is represented by the above formula (1) The compound is obtained by reacting a diamine.

<polylysine>

The above polylysine can be obtained by reacting a tetracarboxylic dianhydride with a diamine containing the compound represented by the above formula (1).

[tetracarboxylic dianhydride]

Examples of the tetracarboxylic dianhydride used in the synthesis of the polyamic acid include butane tetracarboxylic dianhydride, 1,2,3,4-cyclobutane tetracarboxylic dianhydride, and 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-cyclobutanetetracarboxylic dianhydride, 1 , 2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3',4,4'-dicyclohexyltetracarboxylic acid Anhydride, 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-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-two 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-cyclo Hexene-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), 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, the following formula (TI) and (T-II An aliphatic tetracarboxylic dianhydride and an alicyclic tetracarboxylic dianhydride, each of which is represented by a compound;

(In the formulae (TI) and (T-II), R ¹ and R ³ are each a divalent organic group having an aromatic ring, and each of R ² and R ⁴ is a hydrogen atom or an alkyl group, and a plurality of R ² and R ⁴ may each 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 acid Acid dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenyl sulfide dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenylanthracene Dihydride, 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 dianhydride, bis(triphenylphthalic acid)-4,4'-diphenylmethane dianhydride, ethylene glycol-bis(hydroper trimellitate), propylene glycol-double ( Dehydrated trimellitate), 1,4-butanediol - bis (hydrogen trimellitate), 1,6-hexanediol-bis (anhydrotrimellitic acid ester), 1,8-octanediol-bis(anhydrotrimellitic acid ester), 2,2 - An aromatic tetracarboxylic dianhydride such as a compound represented by each of the following formulas (T-1) to (T-4), bis(4-hydroxyphenyl)propane-bis(hydrogen trimellitate).

The benzene ring of the aromatic tetracarboxylic dianhydride may be substituted by one or two or more alkyl groups (preferably methyl groups) having 1 to 4 carbon atoms. They may be used alone or in combination of two or more.

In the synthesis of the poly-proline which is contained in the liquid crystal alignment agent of the present invention, it is preferable to use a selected from the group consisting of butane tetracarboxylic dianhydride and 1, from the viewpoint of the liquid crystal alignment property which can exhibit excellent performance. 2,3,4-cyclobutane tetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentane Alkane tetracarboxylic 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-(tetrahydrogen -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-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, 3,3',4,4'-benzophenone IV Acid dianhydride, 3,3',4,4'-diphenylphosphonium tetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 1,4,5,8- And a compound represented by the following formula (T-5) to (T-7) and a compound represented by the above formula (T-II) in the compound represented by the above formula (TI); A tetracarboxylic dianhydride of at least one of the groups consisting of the compounds represented by the formula (T-8) (hereinafter referred to as "specific tetracarboxylic dianhydride").

More preferably, the specific tetracarboxylic dianhydride is selected from the group consisting of 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-dione, 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-carboxymethylnorborn Alkane-2:3,5:6-dianhydride, 4,9-dioxatricyclo[5.3.1.0 ^2,6 ]undecane-3,5,8,10-tetraketone, pyromellitic acid The anhydride and at least one of the compounds represented by the above formula (T-7) are particularly preferably 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 20 mol% or more based on the total amount of the tetracarboxylic dianhydride used. The specific tetracarboxylic dianhydride preferably contains 40 mol% or more, and more preferably contains 50 mol% or more.

By using a tetracarboxylic dianhydride containing the above respective compounds in the above range, it is possible to synthesize a polylysine having excellent electrical properties or a quinone imidized polymer thereof, and thus it is possible to obtain an excellent display for a liquid crystal alignment agent containing them. The advantages of performance are therefore preferred.

[diamine]

The diamine used in the synthesis of the polyamic acid contained in the liquid crystal alignment agent of the present invention contains the compound represented by the above formula (1).

X in the above formula (1) is preferably -O-*, -COO-* or -OCO-* (wherein the above connection key with "*" is located Y on the side of the ruthenium structure, Y is preferably each -O-*, -COO-*, -OCO-*, -NH-* or -NHCO-* (wherein the above linkage bond with "*" and the amine group) Phenyl bond), R ^I , R ^II and R ^III are each preferably a hydrogen atom or a methyl group.

More specifically, the compound represented by the above formula (1), for example, a compound represented by each of the following formulas (1-1) to (1-14).

In the above formula (1), the position of the two groups Y is preferably 3,5-position with respect to the group X. Further, the position of the amine group, preferably relative to the group Y, is each a para position.

The diamine used in the synthesis of the polyamic acid contained in the liquid crystal alignment agent of the present invention may be a compound represented by the above formula (1), or a compound represented by the above formula (1) or the other two. A combination of amines.

Examples of such other diamines include p-phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylethane, and 4 , 4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl fluorene, 4,4'-diaminobenzimidamide, 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(trifluoromethyl)-4,4'-diaminobiphenyl, 5- Amino-1-(4'-aminophenyl)-1,3,3-trimethylindan, 6-amino-1-(4'-aminophenyl)-1,3,3- Trimethylindan, 3,4'-diaminodiphenyl ether, 3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone, 4,4'-diamine Dibenzophenone, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane , 2,2-bis(4-aminophenyl)hexafluoropropane, bis[4-(4-aminophenoxy)phenyl]anthracene, 1,4-bis(4-aminophenoxy) Benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 9,9-bis(4-aminophenyl)-10- hydrogen , 2,7-diaminopurine, 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, 4,4'-(p-phenylene isopropylidene)diphenylamine 4,4'-(m-phenylene isopropylidene)diphenylamine, 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;

1,1-m-xylylenediamine, 1,3-propanediamine, butanediamine, pentanediamine, hexamethylenediamine, heptanediamine, octanediamine, decanediamine, 1,4-diamino ring Hexane, isophorone diamine, tetrahydrodicyclopentadiene diamine, hexahydro-4,7-methylene dimethylene diamine, tricyclo[6.2.1.0 ^2,7 ] eleven carbon Dimethyldiamine, 4,4'-methylenebis(cyclohexylamine), 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane And other aliphatic diamines and alicyclic diamines;

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 ( Compound represented by DI)

(In the formula (DI), R ⁵ is selected from the group consisting of pyridine, pyrimidine, and tri Piperidine and piperazine a compound represented by the following formula (D-II) having a monovalent organic group having a cyclic structure of a nitrogen atom, X ¹ being a divalent organic group;

(wherein R ⁶ is selected from the group consisting of pyridine, pyrimidine, and tri Piperidine and piperazine A divalent organic group having a nitrogen atom constituting the cyclic structure of the group, each X ² is a divalent organic group, each of the plurality of X ² may be present in the same or different) a molecule having two or a monosubstituted phenylenediamine such as a diamine of a nitrogen atom other than the primary amino group or a compound represented by the following formula (D-III)

(In the formula (D-III), R ⁷ is -O-*, -COO-*, -OCO-*, -NHCO-*, -CONH-* or -CO-* (wherein the above has "*" The linking bond is bonded to R ⁸ ), and R ⁸ is a skeleton or group having a skeleton selected from the group consisting of a steroid skeleton, a trifluoromethylphenyl group, a trifluoromethoxyphenyl group, and a fluorophenyl group. a divalent organic oxoxane such as a compound represented by the following formula (D-IV), a valence organic group or an alkyl group having 6 to 30 carbon atoms or a fluoroalkyl group;

(In the formula (D-IV), R ^{9 is} each a hydrocarbon group having 1 to 12 carbon atoms, and a plurality of R ⁹ groups may be the same or different, each p is an integer of 1 to 3, and q is 1 to An integer of 20); a compound represented by each of the following formulas (D-1) to (D-5)

(y in the formula (D-4) is an integer of 2 to 12, and z in the formula (D-5) is an integer of 1 to 5). The aromatic diamine, the monosubstituted phenyl diamine, a diamine having two primary amino groups in the molecule and a nitrogen atom other than the primary amino group, and a compound represented by each of the above formulas (D-1) to (D to 5) The benzene rings may be substituted by one or two or more alkyl groups (preferably methyl groups) having 1 to 4 carbon atoms, respectively. These diamines may be used alone or in combination of two or more.

R ⁷ in the above formula (D-III) is preferably -O-*, -COO-* or -OCO-* (wherein the above-mentioned "*" linkage is bonded to R ⁸ ), and R ^{8 is} preferably. a straight carbon or a branched alkyl group having a carbon atom number of 8 to 30 or a linear or branched alkyl group having 8 to 30 carbon atoms or a halogen atom substituted by a fluorine atom and having a carbon number of 8 to 30 Chain or branched fluoroalkyl. Specific examples of the compound represented by the above formula (D-III) include compounds represented by the following formulas (D-6) to (D-14), and the like.

The other diamine used in the synthesis of the polylysine of the present invention preferably contains p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4-diaminodiphenylsulfide selected from the above. Ether, 1,5-diaminonaphthalene, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-4,4'-di Aminobiphenyl, 2,7-diaminostilbene, 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)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(aminomethyl)cyclohexane, a compound represented by each of the above formulas (D-1) to (D-5), 2,6-diaminopyridine, 3,4-diamine Pyridine, 2,4-diaminopyrimidine, 3,6-diaminoacridine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, N-B Base-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N,N'- (4-Aminophenyl)benzidine, a compound represented by the following formula (D-15) in the compound represented by the above formula (DI), and a compound represented by the above formula (D-II): -16) the indicated compound,

In the group consisting of the compound represented by the above formula (D-III) and the 1,3-bis(3-aminopropyl)-tetramethyldioxane in the compound represented by the above formula (D-IV) At least one, more preferably at least one selected from the group consisting of p-phenylenediamine and a compound represented by the above formula (D-III).

The diamine used in the synthesis of the polyamic acid of the present invention preferably contains 5 mol% or more of the diamine represented by the above formula (1), more preferably 5 to 50 mol%, further based on the total amount of the diamine. It preferably contains 8 to 40 mol%.

The diamine used in the synthesis of the polyamic acid of the present invention preferably further contains at least one selected from the group consisting of p-phenylenediamine and a compound represented by the above formula (D-III). When the diamine contains p-phenylenediamine, the p-phenylenediamine is preferably 95 mol% or less, more preferably 50 to 80 mol%, based on the total amount of the diamine. Further, when the diamine contains the compound represented by the above formula (D-III), the compound represented by the above formula (D-III) is preferably 40 mol% or less, more preferably 1 to 1% based on the total amount of the diamine. 30% by mole, more preferably 1 to 20% by mole. Here, when the diamine contains the compound represented by the above formula (D-III), the total use ratio of the compound represented by the above formula (1) and the compound represented by the above formula (D-III) is relative to the total amount of the diamine. It is preferably more than 5 mol% and is 50 mol% or less, more preferably 8 to 40 mol%.

By using a diamine containing each compound in the range described above, it is possible to synthesize a polyaminic acid or a quinone imidized polymer capable of exhibiting a stable liquid crystal alignment property, and thus it is possible to obtain a liquid crystal alignment agent containing them. It is preferable to produce an advantage that the alignment unevenness is poorly displayed.

[Synthesis of polyglycine]

The use ratio of the tetracarboxylic dianhydride to the diamine supplied to the polyaminic acid synthesis reaction is preferably 0.2 to 2 equivalents based on 1 equivalent of the amine group contained in the diamine. The ratio is more preferably a ratio of 0.3 to 1.2 equivalents.

The synthesis reaction of poly-proline is preferably carried out in an organic solvent, preferably at a temperature of from -20 to 150 ° C, more preferably from 0 to 100 ° C, preferably from 0.1 to 99 hours, more preferably 0.5. ~48 hours. Here, the organic solvent is not particularly limited as long as it can dissolve the synthesized polyamic acid, and examples thereof include N-methyl-2-pyrrolidone, N,N-dimethylacetamide, and N. Aprotic polar solvents such as N-dimethylformamide, dimethyl hydrazine, γ-butyrolactone, tetramethylurea, hexamethylphosphonium triamine; m-methylphenol, xylenol, phenol, A phenolic solvent such as a 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 the above organic solvent is used in combination with the poor solvent described below, the amount (a) of the above organic solvent means the total amount of the organic solvent and the poor solvent.

In the above organic solvent, alcohols, ketones, esters, ethers, halogenated hydrocarbons which are generally considered to be poor solvents of polyaminic acid may be used in combination in a range in which the produced polyaminic acid is not precipitated. , hydrocarbons, etc. Specific examples of such a poor solvent include methanol, ethanol, isopropanol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, and ethylene glycol monomethyl ether. Ethyl lactate, butyl lactate, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, methyl methoxypropionate, ethoxylate Ethyl propionate, 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, B 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, tetrahydrofuran, dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, 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 above-mentioned poor solvent, the use ratio of the poor solvent is preferably 80% by weight or less, more preferably 60% by weight or less, and still more preferably 50% based on the total amount of the organic solvent and the poor 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 using an evaporator. Further, the polylysine can be purified by repeating the step 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 quinone imidized polymer contained in the liquid crystal alignment agent of the present invention can be obtained by dehydrating and ring-closing the polylysine obtained as described above.

The tetracarboxylic dianhydride used in the synthesis of the quinone imidized polymer contained in the liquid crystal alignment agent of the present invention is the same as the tetracarboxylic dianhydride used in the synthesis of the above polyamic acid. In the case where the tetracarboxylic dianhydride preferably contains the above specific tetracarboxylic dianhydride, the specific use ratio of the specific tetracarboxylic dianhydride is also the same as that of the polyamic acid. Among them, among the specific tetracarboxylic dianhydrides used in the synthesis of the ruthenium iodide polymer, it is preferably selected from the group consisting of 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 : at least one of the group consisting of 3,5:6-dianhydride and 4,9-dioxatricyclo[5.3.1.0 ^2,6 ]undecane-3,5,8,10-tetraketone, Particularly preferred is 2,3,5-tricarboxycyclopentyl acetic acid dianhydride.

[diamine]

The diamine used in the synthesis of the above quinone imidized polymer may be the same diamine as the diamine used in the synthesis of the above polyamic acid.

[Synthesis of ruthenium iodide polymer]

The ruthenium iodide polymer contained in the liquid crystal alignment agent of the present invention may be a complete ruthenium imide of the guanylate structural unit of the precursor polyamic acid, which may be dehydrated and closed, or may be a guanine unit. A portion of the quinone imide that coexists with the dehydrated closed-loop quinone ring. The ruthenium imidization ratio of the ruthenium iodide polymer is preferably 30% or more, more preferably 40% or more. Here, the "rhodium imidization ratio" means a value which is a percentage of the ratio of the number of guanidine groups in the polymer to the number of quinone rings, and the ratio of the number of iridium rings. 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, obtained 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 derived 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 ( One NH matrix in poly-proline), the ratio of the number of other protons).

The quinone imidized polymer constituting the liquid crystal alignment agent of the present invention can be obtained by dehydration ring closure of the above polyglycolic acid. The dehydration ring closure of polylysine may be (i) by heating the poly-proline, or (ii) by dissolving the poly-proline in an organic solvent, adding a dehydrating agent and a dehydration ring-closing catalyst to the solution, as needed The heating method is carried out.

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 0.1 to 99 hours, more preferably from 0.5 to 72 hours.

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 use ratio of the dehydrating agent is preferably from 0.01 to 20 mols per 1 mol of the repeating unit of the polyglycolic acid. Further, as the dehydration ring-closure catalyst, a tertiary amine such as pyridine, trimethylpyridine, lutidine or triethylamine can be used. However, it is not limited to these. The use ratio of the dehydration ring-closure catalyst is preferably 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. Further, 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 0.1 to 48 hours, more preferably 0.5 to 24 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 the separation and purification method of polyglycine.

- terminal modified polymer -

The above polylysine and its quinone imidized polymer may also be a terminal modified polymer having a molecular weight adjusted. Such a terminal-modified polymer can be synthesized by adding a molecular weight modifier to a reaction system during the synthesis of poly-proline. Examples of the molecular weight modifier include a monoanhydride, a monoamine compound, and a monoisocyanate compound.

Here, examples of the monoanhydride include maleic anhydride, phthalic anhydride, itaconic anhydride, n-decyl succinic anhydride, n-dodecyl succinic anhydride, n-tetradecyl succinic anhydride, and n-hexadecane. 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 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 molecular weight modifier is preferably 10 parts by weight or less, more preferably 5 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 polylysine and the quinone imidized polymer obtained as above have a solution viscosity of 20 to 800 mPa·s, preferably 30 to 500 mPa·s, when formulated into a solution having a concentration of 10% by weight, respectively. Viscosity.

The solution viscosity (mPa‧s) of the above polymer is a good solvent (for example, N-methyl-2-pyrrolidone, etc.) using the polymer to prepare a 10% by weight polymer solution, and the E-type rotational viscosity is used. The value measured at 25 ° C was counted.

<Other ingredients>

The liquid crystal alignment agent of the present invention contains at least one selected from the group consisting of polylysine as described above and its quinone imidized polymer.

The liquid crystal alignment agent of the present invention may further contain other components in addition to at least one selected from the group consisting of the above polylysine and its quinone imidized polymer, without impairing the effect of the present invention. Examples of such other components include polymers other than the above-mentioned polyaminic acid and its quinone imidized polymer (hereinafter referred to as "other polymers"), and compounds having at least two epoxy groups in the molecule (hereinafter referred to as It is called an "epoxy compound", a functional decane compound, etc.

<Other polymers>

Examples of the other polymer include polylysine other than the above (hereinafter referred to as "other polyphthalic acid"), and a ruthenium iodide polymer (hereinafter referred to as "other quinone imidized polymer"). , polyglycolate, polyester, polyamine, cellulose derivative, polyacetal, polystyrene derivative, poly(styrene-phenylmaleimide) derivative, poly(methyl) Acrylate and the like. Among them, as the other polymer, at least one selected from the group consisting of other polyaminic acid and other quinone-imidized polymers is preferably used. These other polylysines and their ruthenium iodide polymers may be used in addition to the above-mentioned polyamines and their oxime, in addition to the tetracarboxylic dianhydride and the diamine not containing the compound represented by the above formula (1). Synthesis of aminated polymers by synthetic methods. The tetracarboxylic dianhydride used as the raw material at this time preferably contains at least one selected from the group consisting of alicyclic tetracarboxylic dianhydride and pyromellitic dianhydride, and particularly preferably contains 1, 2, At least one of the group consisting of 3,4-cyclobutanetetracarboxylic dianhydride and pyromellitic dianhydride. As the diamine, a diamine containing an aromatic diamine, particularly preferably a 4,4'-diaminodiphenylmethane and a 2,2'-dimethyl-4,4'-diamine group are preferably used. A diamine of at least one of the group consisting of benzene. As other polymers, it is more preferred to use other polylysines.

When the liquid crystal alignment agent of the present invention contains other polymers, the content ratio of the other polymers is preferably 75% by weight or less based on the total amount of the polyamic acid and its ruthenium iodide polymer and other polymers. More preferably, it is 65% by weight or less, further preferably 60% by weight or less.

The liquid crystal alignment agent of the present invention may contain an epoxy compound from the viewpoint of improving the adhesion to the surface of the substrate. Preferred examples of such an epoxy compound include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, and polypropylene glycol diglycidyl glycol. Ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerol diglycidyl ether, trimethylolpropane triglycidyl ether, 2,2-dibromo neopentyl glycol Glycidyl 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-aminol Cyclohexane, N,N-diglycidyl-cyclohexylamine, and the like. The mixing ratio of these epoxy compounds is preferably a total amount of 100 parts by weight of the polymer (refers to the total amount of the above polylysine and its ruthenium iodide polymer and other polymers. The same applies hereinafter). 40 parts by weight or less, more preferably 0.1 to 30 parts by weight.

The functional decane compound may, for example, be 3-aminopropyltrimethoxydecane, 3-aminopropyltriethoxydecane, 2-aminopropyltrimethoxydecane or 2-aminopropylamine. Triethoxy decane, N-(2-aminoethyl)-3-aminopropyltrimethoxydecane, N-(2-aminoethyl)-3-aminopropylmethyl dimethyl Oxydecane, 3-ureidopropyltrimethoxydecane, 3-ureidopropyltriethoxydecane, N-ethoxycarbonyl-3-aminopropyltrimethoxydecane, N-ethoxycarbonyl- 3-aminopropyltriethoxydecane, N-triethoxydecylpropyltriethylenetriamine, N-trimethoxydecylpropyltriethylenetriamine, 10-trimethoxydecylalkyl -1,4,7-triazadecane, 10-triethoxydecyl-1,4,7-triazadecane, 9-trimethoxydecyl-3,6-diazaindole Acetate, 9-triethoxydecyl-3,6-diazadecyl acetate, methyl 9-trimethoxydecyl-3,6-diazadecanoate, 9-three Methyl ethoxyalkylalkyl-3,6-diazepine, N-benzyl-3-aminopropyltrimethoxydecane, N-benzyl-3-aminopropyltriethoxydecane N-phenyl-3-amino group Trimethoxy decane, N-phenyl-3-aminopropyl triethoxy decane, glycidoxymethyl trimethoxy decane, glycidoxymethyl triethoxy decane, 2- Glycidoxyethyltrimethoxydecane, 2-glycidoxyethyltriethoxydecane, 3-glycidoxypropyltrimethoxydecane, 3-glycidoxypropyl Triethoxy decane and the like.

The mixing ratio of the functional decane compound is preferably 40 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 selected from the group consisting of polylysine as described above and its quinone imidized polymer, and other components optionally blended as needed are preferably dissolved in an organic solvent. Composed of

Examples of the organic solvent which can be 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, ethoxy Ethyl propyl propionate, 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, B Glycol diethyl 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 Ester, diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, isoamyl ether, ethylene carbonate, propylene carbonate, and the like. They 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. 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, the particularly preferable solid content concentration is 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.

<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 (4).

(1) Applying the liquid crystal alignment agent of the present invention to the substrate provided with the patterned transparent conductive film by an appropriate coating method such as an offset printing method, a spin coating method, or an inkjet printing method, and then passing The coated surface is heated to form a coating film. 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. . The pattern of these transparent conductive films may be formed by photolithography or a method of using a mask 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 liquid crystal alignment agent is applied, in order to prevent the coating agent liquid from sagging, etc., it is preferred to perform preheating (prebaking) first. 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 0.1 to 60 minutes, more preferably from 0.5 to 30 minutes. Then, after the solvent is completely removed, it is preferred to further carry out a 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 0.5 to 180 minutes, more preferably from 1 to 120 minutes. The liquid crystal alignment agent of the present invention forms a coating film as an alignment film by coating the organic solvent as described above, and when the phthalic acid structure remains in the polymer contained in the liquid crystal alignment agent of the present invention, it is also possible to form a coating film. The film is subjected to a dehydration ring-closure reaction by further heating to form a further ruthenium-coated film.

The thickness of the formed coating film 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 subjected to a polishing treatment as described below. Further, when the liquid crystal alignment agent of the present invention is applied to a level-aligned liquid crystal alignment film such as a TN type or an STN type, it is necessary to polish the coating film formed as described above.

In the above-mentioned polishing treatment, the coating film surface may be rubbed in a certain direction by a roll wrapped with a cloth made of a suitable fiber such as nylon, rayon or cotton, and used as a liquid crystal alignment film. In addition, a part of the liquid crystal alignment film shown in the patent document 2 (JP-A-H06-222366) or the patent document 3 (JP-A-6-281937) is applied to the coating film. a process of changing the pretilt angle of a part of the liquid crystal alignment film by irradiating the ultraviolet ray, or forming a protective film on a part of the surface of the liquid crystal alignment film as shown in Patent Document 4 (Japanese Laid-Open Patent Publication No. Hei No. 5-105044) The treatment for removing the protective film after the sanding treatment is performed in the different direction of 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 performance of the obtained liquid crystal display element.

(3) A liquid crystal alignment film obtained as described in the above (1) to (2), which may then be washed as needed. As the washing solvent, for example, water, acetone, methanol, ethanol, isopropanol, cyclohexanol, ethylene glycol, propylene glycol, methyl ethyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate can be used. , tetrahydrofuran, hexane, heptane, octane, and the like. In order to improve the cleaning efficiency, it may be carried out by at least one selected from the group consisting of a method of adding a surfactant to a cleaning solvent, a method of washing with a heating solvent, a method of combining with a brushing, and a method of using ultrasonic waves. Use together. After washing, it may be used as a liquid crystal alignment film as it is, or may be further washed with a suitable solvent, and then, if necessary, removed by heating, and then used.

(4) Two substrates on which the liquid crystal alignment film is formed are formed, and the two substrates are placed opposite each other through a gap (cell gap), and in the case of being polished, the polishing directions of the respective liquid crystal alignment films are perpendicular or antiparallel to each other. The peripheral portions of the two substrates are bonded together with a sealant, and liquid crystal is injected into the gap between the substrate and the sealant, and the injection holes are closed to form a liquid crystal cell. Then, a 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, that is, the other side surface of each of the substrates constituting the liquid crystal cell.

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 preferred, and for example, a Schiff base liquid crystal, an azo-based liquid crystal, a biphenyl liquid crystal, or a phenyl ring may be used. An alkane liquid crystal, an ester liquid crystal, a terphenyl liquid crystal, a biphenyl cyclohexane liquid crystal, a pyrimidine liquid crystal, a dioxane liquid crystal, a bicyclooctane liquid crystal, a 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 added, and the trade names "C-15" and "CB-15" (manufactured by Merck & Co., Inc.) may be added. A chiral agent is sold, and a ferroelectric liquid crystal such as decyloxybenzylidene-p-amino-2-methylbutyl cinnamate is used.

The polarizing plate to which the outer surface of the liquid crystal cell is bonded is a polarizing plate or H which is obtained by sandwiching a polarizing film called "H film" which is obtained by absorbing iodine while absorbing iodine, and sandwiching it on a cellulose acetate protective film. A polarizing plate made of the film itself.

<Surface free energy of liquid crystal alignment film>

The liquid crystal alignment film formed of the liquid crystal alignment agent of the present invention has a characteristic that the surface free energy is small as compared with the conventionally known liquid crystal alignment film. It is presumed that due to such characteristics, the liquid crystal display element having the same can exhibit uniform liquid crystal alignment and is excellent in afterimage performance. The liquid crystal alignment film formed by the liquid crystal alignment agent of the present invention has a surface free energy of 38 mN/m or less, 37 mN/m or less, or even 36 mN/m or less.

The liquid crystal alignment film formed of the liquid crystal alignment agent of the present invention can be suitably used as a liquid crystal alignment film for a vertical alignment type liquid crystal display element.

[Examples]

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

In the following examples, the ruthenium imidization ratio of the ruthenium iodide polymer is obtained by dissolving the ruthenium iodide polymer under sufficient reduced pressure at room temperature and then dissolving it in deuterated dimethyl hydrazine. Tetramethyl decane was used as a reference material, and ¹ H-NMR was measured at room temperature, and the measured ¹ H-NMR spectrum was calculated according to the above formula (i).

The solution viscosity of the polymer solution was measured at 25 ° C using an E-type rotational viscometer.

Synthesis Example 1 (Synthesis Example of Compound represented by the above formula (1))

Under a nitrogen atmosphere, 21.5 g (0.05 mol) of DL-α-tocopherol, 5.3 g (0.0525 mol) of triethylamine and 150 ml of tetrahydrofuran were added to a 500 ml three-necked flask, and stirred at 0 °C. A solution consisting of 10.9 g (0.0525 mol) of 3,5-dichlorobenzamide chloride and 50 ml of tetrahydrofuran was added dropwise thereto over 30 minutes. The solution was then stirred at room temperature for 3 hours to carry out the reaction. Then, after the salt precipitated from the reaction system was filtered off, tetrahydrofuran was distilled off from the solution. To the solid obtained as a result, 200 ml of chloroform was added to dissolve them all, and the organic layer was washed with distilled water. The organic layer was dehydrated with magnesium sulfate, and then concentrated on a rotary evaporator. The obtained crude product was purified by silica gel column chromatography (developing solvent: chloroform), and then recrystallized from ethanol to obtain 29.5 g of dichloro intermediate.

Then, the above synthesized intermediates were 15.1 g (0.025 mol), 4-nitrophenol 7.3 g (0.0525 mol), and potassium carbonate 20.7 g (0.15 mol) in a 1000 ml three-necked flask under a nitrogen atmosphere. The mixture was mixed, and 300 ml of dimethylformamide was added thereto, followed by further stirring. The solution was stirred under nitrogen at room temperature for 6 hours to carry out a reaction. After completion of the reaction, 300 ml of distilled water was added to the reaction solution, and the mixture was thoroughly stirred, and then extracted with 300 ml of chloroform, and the obtained organic layer was washed with distilled water. The organic layer was then dehydrated with magnesium sulfate, and concentrated using a rotary evaporator. The obtained crude product was recrystallized from ethanol to give 17.2 g of the compound of the formula (1-5-1a) below. 1a)).

Then, 16.2 g (0.02 mol) of the above synthesized compound (1-5-1a) and 45.1 g (0.2 mol) of tin chloride dihydrate were mixed in a 300 ml three-necked flask under a nitrogen atmosphere. , add 150ml to it Ethyl acetate was added, and the resulting solution was heated and stirred under reflux for 3 hours under nitrogen to carry out a reaction. After completion of the reaction, the reaction solution was mixed with 400 ml of a saturated aqueous potassium fluoride solution and stirred well, and the mixture was separated, and the obtained organic layer was washed with distilled water. The organic layer was dehydrated with magnesium sulfate, and concentrated by a rotary evaporator. The obtained crude product was recrystallized from ethanol to give 14.2 g of the compound of formula (1-5-1). )).

Comparative Synthesis Example 1 (comparison of comparative diamines)

The compound (compound (R-1)) represented by the following formula (R-1), which is a comparative diamine, is synthesized by the method described in Patent Document 1 (JP-A-2001-97969).

Synthesis Examples 2 to 9 and Comparative Synthesis Example 2 (Synthesis of ruthenium iodide polymer)

To N-methyl-2-pyrrolidone, the kinds and amounts of diamine and tetracarboxylic dianhydride shown in Table 1 were sequentially added to prepare a total amount of tetracarboxylic dianhydride and diamine (b) relative to the reaction. The total amount of the solution (a+b) was 20% by weight of the solution, and it was reacted at 60 ° C for 4 hours to obtain polyamine acids (A-1) to (A-8) and (a-1), respectively. The solution. A small amount of each of these solutions was added, and N-methyl-2-pyrrolidone was separately added to prepare a solution having a polyglycine concentration of 10% by weight. The measured solution viscosity is shown in Table 1.

To the polyglycine-containing solution prepared above, pyridine and acetic anhydride were added in an amount shown in Table 1 with respect to the number of methionine units per polyglycolic acid, and heated at 110 ° C. The dehydration ring closure reaction takes place in an hour After the dehydration ring closure reaction, the solvent in the system is replaced with a new N-methyl-2-pyrrolidone (in this operation, the pyridine and acetic anhydride used in the dehydration ring-closure reaction are removed to the outside of the system), respectively, to obtain A solution of 15% by weight of the quinone imidized polymers (B-1) to (B-8) and (b-1). The viscosity of the solution of the ruthenium imidization polymer and the solution viscosity value determined by adding a small amount of each solution and adding N-methyl-2-pyrrolidone to a solution having a concentration of 10% by weight of the ruthenium polymer In Table 1.

Synthesis Examples 10 and 11 (synthesis of poly-proline)

To N-methyl-2-pyrrolidone, the kinds and amounts of diamine and tetracarboxylic dianhydride shown in Table 1 were sequentially added to prepare a total amount of tetracarboxylic dianhydride and diamine (b) relative to the reaction. The total amount of the solution (a+b) was 20% by weight of the solution, and it was reacted at 60 ° C for 4 hours to obtain polyglycine (A-9), (A-10), (a-2), respectively. And the solution of (a-3). A small amount of each of these solutions was added, and N-methyl-2-pyrrolidone was separately added to prepare a solution having a polyglycine concentration of 10% by weight. The measured solution viscosity is shown in Table 1.

Comparative Synthesis Examples 3 and 4 (comparison of comparative polyamines)

To N-methyl-2-pyrrolidone, after adding the kinds and amounts of the diamines and dicarboxylic acids shown in Table 2, respectively, 2 mols and 10 were added thereto separately with respect to 1 mol of the dicarboxylic acid. The total amount of bromide phosphite and pyridine as a condensing agent, and the total amount of the diamine, dicarboxylic acid, triphenyl phosphite and pyridine (b) relative to the total amount of the reaction solution (a+b) A 20% by weight solution was allowed to react at 120 ° C for 3 hours to obtain a solution containing polyamines (a-2) and (a-3), respectively. A small amount of each of these solutions was added, and N-methyl-2-pyrrolidone was added thereto to prepare a solution having a polyglycine concentration of 10% by weight. The measured solution viscosity is shown in Table 2.

In Tables 1 and 2, the abbreviations of diamine and tetracarboxylic dianhydride have the following meanings, respectively.

[diamine]

D-1: Compound (1-5-1)

D-2: a compound represented by the above formula (D-8)

D-3: a compound represented by the above formula (D-10)

D-4: Compound (R-1)

D-5: p-phenylenediamine

D-6: 4,4'-diaminodiphenylmethane

D-7: 2,2'-dimethyl-4,4'-diaminobiphenyl

[tetracarboxylic dianhydride]

T-1: 2,3,5-tricarboxycyclopentyl acetic acid dianhydride

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

T-3: pyromellitic dianhydride

[dicarboxylic acid]

C-1: terephthalic acid

Example 1

The solution containing the quinone imidized polymer (B-1) prepared in the above Synthesis Example 2 was measured in an amount equivalent to 100 parts by weight in terms of conversion to the ruthenium iodide polymer (B-1). Add γ-butyrolactone (BL), N-methyl-2-pyrrolidone (NMP) and butyl cellosolve (BC), and add 5 parts by weight of N, N, N', N'- as an epoxy compound. Tetraglycidyl-2,2'-dimethyl-4,4'-diaminobiphenyl, formulated in a solvent composition of BL:NMP:BC=40:30:30 (weight ratio), solid content concentration A 4% by weight solution was filtered through a filter having a pore size of 0.2 μm to prepare a liquid crystal alignment agent.

The liquid crystal alignment agent was evaluated as follows. The results are shown in Table 3.

(1) Evaluation of surface free energy of liquid crystal alignment film

On the transparent conductive film made of ITO film provided on one surface of a glass substrate having a thickness of 1 mm, the liquid crystal alignment agent prepared above was applied by spin coating, and heated at 80 ° C for 1 minute (prebaking), and then at 200 After heating at ° C for 60 minutes (post-baking), a coating film (liquid crystal alignment film) having a film thickness of 0,08 μm was formed.

The contact angle between water and diiodomethane was measured for the liquid crystal alignment film, and the surface free energy of the liquid crystal alignment film was determined by the extended Fowkes equation using these measured values.

(2) Manufacturing of liquid crystal display elements

On the transparent conductive film made of ITO film provided on one surface of a glass substrate having a thickness of 1 mm, the liquid crystal alignment agent prepared above was applied by spin coating, and heated at 80 ° C for 1 minute (prebaking), and then at 200 After heating at ° C for 60 minutes (post-baking), a coating film (liquid crystal alignment film) having a film thickness of 0.08 μm was formed. This operation was repeated to fabricate two (a pair of) substrates having a liquid crystal alignment film.

On the outer edges of the pair of substrates having the liquid crystal alignment film, an epoxy resin adhesive having an alumina ball of 3.5 μm in diameter is applied, and the liquid crystal alignment film faces are relatively recombined and pressed, and then The adhesive cures. Next, a negative liquid crystal (MLC-6608, manufactured by Merck & Co., Inc.) was filled between the substrates through a liquid crystal injection port, and then the liquid crystal injection port was closed with an acrylic photocurable adhesive, and a polarizing plate was bonded to both sides of the substrate to manufacture a polarizing plate. A vertical alignment type liquid crystal display element is output.

(3) Evaluation of vertical alignment

For the liquid crystal display element manufactured above, when no voltage was applied and when an AC voltage of 8 V (peak-peak) was applied, the liquid crystal display element was visually observed from the vertical direction, and when no display failure such as light leakage was observed, uniform black was not applied when voltage was applied. It is shown that when the voltage is a uniform white display when applied, the vertical alignment property is evaluated as "good".

(4) Evaluation of voltage retention rate

At a temperature of 60 ° C, a voltage of 5 V was applied to the liquid crystal display element manufactured above for a time span of 167 msec, the voltage application time was 60 μsec, and then the hold voltage ratio from the voltage release to 167 msec was measured. The measuring device was manufactured by Dongyang Technology Co., Ltd. under the product name "VHR-1".

(5) Evaluation of afterimage performance

Two liquid crystal display elements fabricated in the same manner as described above were prepared, and a direct current voltage of 1 V was applied to one of them at room temperature, and a direct current voltage of 5 V was applied to the other, and each was applied for 2 hours. Then, when the applied voltage of the two liquid crystal display elements was 2.5 V, the luminance difference (gradation difference) of the luminance of the two elements when displayed at 256 gray scales was examined. When the value is below 15 gray levels, the afterimage performance can be rated as "good".

Examples 2 to 16 and Comparative Examples 1 to 5

The polymer-containing solution was prepared in the same manner as in Example 1 except that the polymer-containing solution shown in Table 3 was used, and the epoxy group compound of the kind and the use ratio shown in Table 3 was used. Liquid crystal alignment agent and evaluation. The results are shown in Table 3.

Further, in Examples 13 to 16 and Comparative Example 5, two solutions containing a polymer were used.

In Table 3, the value carried in the parentheses after the polymer name is the amount (parts by weight) of the polymer contained in the polymer solution used. The value carried in the parentheses after the epoxy compound is the use ratio (parts by weight) of each epoxy compound.

The abbreviations of the epoxy compounds are respectively the following meanings.

E-1: N, N, N', N'-tetraglycidyl-2,2'-dimethyl-4,4'-diaminobiphenyl

E-2: N, N, N', N'-tetraglycidyl-4,4'-diaminodiphenylmethane

E-3: N, N, N', N'-tetraglycidyl metaxylylenediamine.

Claims (6)

A liquid crystal alignment agent characterized by comprising at least one selected from the group consisting of polylysine and a quinone imidized polymer thereof, which comprises a tetracarboxylic dianhydride and a formula ( 1) a diamine reaction of the indicated compound, In the formula (1), X is a divalent organic group containing an aromatic ring or -O-*, -S-*, -SO ₂ -*, -NH-*, -COO-*, -OCO-*, - NHCO-*, -CONH-*, -CO-*, -CH ₂ O-*, methylene or an alkylene group having 2 to 8 carbon atoms (wherein the above linkage with "*" is located Chrom(chroman) structure side), Y are each -O-*, -S-*, -SO ₂ -*, -NH-*, -COO-*, -OCO-*, -NHCO-*, -CONH- *, -CO-*, methylene or an alkylene group having 2 to 8 carbon atoms (wherein the above-mentioned "*" linkage is bonded to an amine phenyl group), and the two Ys may be identical to each other. Alternatively, each of R ^I , R ^II and R ^{III may} be a hydrogen atom or a monovalent organic group. The liquid crystal alignment agent of claim 1, wherein the diamine further contains at least one selected from the group consisting of p-phenylenediamine and a compound represented by the following formula (D-III). In the formula (D-III), R ⁷ is -O-*, -COO-*, -OCO-*, -NHCO-*, -CONH-* or -CO-*, (wherein, the above has "*" a linkage to R ⁸ ), and R ⁸ is a skeleton or group having a group selected from the group consisting of a steroid skeleton, a trifluoromethylphenyl group, a trifluoromethoxyphenyl group, and a fluorophenyl group. A monovalent organic group or an alkyl group or a fluoroalkyl group having 6 to 30 carbon atoms. A liquid crystal alignment agent according to claim 1 or 2, wherein the tetracarboxylic dianhydride contains 2,3,5-tricarboxycyclopentyl acetic acid dianhydride. A liquid crystal alignment film formed of the liquid crystal alignment agent according to any one of claims 1 to 3. The liquid crystal alignment film of claim 4 of the patent application has a surface free energy of 38 mN/m or less. A liquid crystal display element characterized by having a liquid crystal alignment film according to item 4 or 5 of the patent application.