JP5013105B2 - Liquid crystal aligning agent and liquid crystal display element - Google Patents

Description

  The present invention relates to a liquid crystal aligning agent and a liquid crystal display element used for forming a liquid crystal alignment film of a liquid crystal display element. More specifically, the present invention relates to a liquid crystal aligning agent that provides a liquid crystal aligning film having good electrical characteristics and good printability, and a liquid crystal display element including a liquid crystal aligning film obtained from the liquid crystal aligning agent.

Currently, as a liquid crystal display element, a liquid crystal alignment film made of polyamic acid, polyimide, or the like is formed on the surface of a substrate provided with a transparent conductive film such as ITO (indium oxide-tin oxide) to form a substrate for a liquid crystal display element. Two of them are placed facing each other and a nematic liquid crystal layer having a positive dielectric anisotropy is formed in the gap to form a sandwich cell, where the major axis of the liquid crystal molecules is directed from one substrate to the other. There is known a TN liquid crystal display element having a so-called TN (twisted nematic) liquid crystal cell that is continuously twisted by 90 °. Further, STN (Super Twisted Nematic) type liquid crystal display elements have been developed that have higher contrast than TN type liquid crystal display elements and have less viewing angle dependency. This STN type liquid crystal display element uses nematic liquid crystal blended with a chiral agent which is an optically active substance as liquid crystal, and the major axis of liquid crystal molecules is continuously twisted over 180 ° between substrates. The birefringence effect generated by the above is utilized.
In addition to these, a vertical alignment type liquid crystal display element called an MVA (Multi-Domain Vertical Alignment) method in which protrusions are formed on a transparent conductive film to control the alignment direction of the liquid crystal has been proposed (Patent Document 1 and Non-Patent Document 1). (See Patent Document 1). The MVA liquid crystal display element is excellent in terms of manufacturing process, such as excellent viewing angle, contrast, and the like, and does not need to be rubbed in forming the liquid crystal alignment film.
The liquid crystal alignment film suitable for the TN, STN, and MVA methods is required to have electrical characteristics such as a short afterimage erasing time of the liquid crystal display element. Furthermore, the alignment agent used for forming these liquid crystal alignment films is required to have excellent printability in offset printing.
Japanese Patent Laid-Open No. 11-258605 JP-A-6-222366 JP-A-6-281937 JP-A-5-107544 “Liquid Crystal”, Vol. 3 (No. 2), p117 (1999)

  The present invention has been made based on the above circumstances, and an object of the present invention is to provide a liquid crystal alignment film having a reduced accumulated charge while maintaining a high voltage holding ratio in a polyimide-based liquid crystal alignment film. It is an object of the present invention to provide a liquid crystal aligning agent that can be manufactured and has excellent printability, and a liquid crystal display element that is excellent in display quality and image sticking characteristics.

According to the present invention, the object of the present invention is firstly
The following formulas (1) and (2)

A tetracarboxylic dianhydride containing at least one selected from the group consisting of compounds represented by each of the following formulas (3) to (6):

Wherein R ^{1 to} R ⁴ are each independently a linear, branched or cyclic alkyl group having 1 to 40 carbon atoms, or a linear, branched or cyclic alkenyl group having 4 to 40 carbon atoms. And ¹ to 15 hydrogen atoms of R ^{1 to} R ⁴ may be substituted with fluorine atoms, and A ¹ and A ² are each independently a hydrogen atom or a methyl group.)
A polyamic acid and / or imidized polymer thereof obtained by a reaction with a diamine containing at least one selected from the compounds represented by:
Following formula (7)

(Where X ¹ represents the following formula (7-1) or (7-2)

(Here, R ⁵ is each independently a methylene group or polymethylene group, R ⁶ is an alkyl group, and a and b are each independently an integer of 1 to 20.)
And m and n are each independently an integer of 1 to 20. )
And a liquid crystal aligning agent containing a solvent.
According to the present invention, the above object of the present invention is secondly achieved by a liquid crystal display device comprising a liquid crystal alignment film obtained from the above liquid crystal aligning agent.

  The liquid crystal aligning agent of this invention is tetracarboxylic dianhydride containing at least 1 sort (s) selected from the group which consists of a compound represented by each of said formula (1) and (2), and said formula (3)- (6) a polyamic acid (hereinafter referred to as “specific polyamic acid”) and / or an imidized polymer thereof obtained by a reaction with a diamine containing at least one selected from the group consisting of the compounds represented by each of (6) Containing. Hereinafter, the tetracarboxylic dianhydride and diamine used for synthesizing the specific polyamic acid and / or the imidized polymer thereof contained in the liquid crystal aligning agent of the present invention will be described.

<Tetracarboxylic dianhydride>
The tetracarboxylic dianhydride used for the synthesis of the specific polyamic acid and / or imidized polymer thereof is 2,3,5-tricarboxycyclopentylacetic dianhydride represented by the above formula (1) and the above formula ( 2) at least one selected from the group consisting of 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride And “specific tetracarboxylic dianhydride”).
As the tetracarboxylic dianhydride used in the synthesis of the specific polyamic acid and / or imidized polymer thereof, only the specific tetracarboxylic dianhydride may be used, or the specific tetracarboxylic dianhydride may be used. And other tetracarboxylic dianhydrides may be used in combination. Examples of other tetracarboxylic dianhydrides that can be used here include alicyclic tetracarboxylic dianhydrides (excluding specific tetracarboxylic dianhydrides), aliphatic tetracarboxylic dianhydrides, and the like. Products, aromatic tetracarboxylic dianhydrides and the like.

Examples of the alicyclic tetracarboxylic dianhydride include 1,2,3,4-cyclobutanetetracarboxylic 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-cyclohexanetetra Carboxylic dianhydride, 3,3 ′, 4,4′-dicyclohexyltetracarboxylic dianhydride, cis-3,7-dibutylcycloocta-1,5-diene-1,2,5,6-tetracarboxylic Acid dianhydride 3,5,6-tricarbonyl-2-carboxynorbornane-2: 3,5: 6-dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 1,2,4-tri Carboxycyclopentyl acetic acid dianhydride, tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodecane-3,4,8,9-tetracarboxylic dianhydride, 1,3,3a, 4,5,9b-hexahydro-5 (tetrahydro-2,5-dioxo-3-furanyl) -Naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5-methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -Naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5-ethyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -Naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-7-methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) Naphtho [1,2-c] -furan-1,3-dione, 1, , 3a, 4,5,9b-Hexahydro-7-ethyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3 , 3a, 4,5,9b-Hexahydro-8-methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3 , 3a, 4,5,9b-Hexahydro-8-ethyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3 , 3a, 4,5,9b-Hexahydro-5,8-dimethyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [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), 3, 5, 6 -Tricarboxy-2-carboxynorbornane-2: 3,5: 6-dianhydride, 4,9-dioxatricyclo [5.3.1.0 ^2,6 ] undecane-3,5,8,10 -Tetraone, the following formula (I) or (II)

(Here, R ⁷ and R ⁹ each represent a divalent organic group having an aromatic ring, R ⁸ and R ¹⁰ each represent a hydrogen atom or an alkyl group, and a plurality of R ⁸ and R ^{10 are present.} May be the same or different.)
The compound etc. which are represented by these can be mentioned.
Examples of the aliphatic tetracarboxylic dianhydride include butanetetracarboxylic dianhydride.
Examples of the aromatic tetracarboxylic dianhydride include pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, and 3,3 ′, 4,4′-biphenylsulfone. Tetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyl Ether tetracarboxylic dianhydride, 3,3 ′, 4,4′-dimethyldiphenylsilane tetracarboxylic dianhydride, 3,3 ′, 4,4′-tetraphenylsilane tetracarboxylic dianhydride, 1, 2,3,4-furantetracarboxylic dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) Zife Rusulfone dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenylpropane dianhydride, 3,3 ′, 4,4′-perfluoroisopropylidenediphthalic dianhydride, 2,2 ', 3,3'-biphenyltetracarboxylic dianhydride, 3,3', 4,4'-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 (anhydro trimellitate), propylene glycol bis (anhydro trimellitate) ), 1,4-butanediol-bis (anhydrotrimellitate), 1,6-hexanediol-bis (anhydrotrimellitate), 1,8-octanediol-bis (anhydrotrimellitate), 2,2-bis (4-hydroxyphenyl) propane-bis (anhydrotrimellitate), the following formulas (8) to (11)

The compound etc. which are represented by these can be mentioned.
These other tetracarboxylic dianhydrides can be used alone or in combination of two or more.
Among the other tetracarboxylic dianhydrides, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3 are used as alicyclic tetracarboxylic dianhydrides. , 4-Cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic Acid dianhydride, 1,2,4-tricarboxycyclopentyl acetic acid dianhydride, cis-3,7-dibutylcycloocta-1,5-diene-1,2,5,6-tetracarboxylic dianhydride, 3,5,6-tricarbonyl-2-carboxynorbornane-2: 3,5: 6-dianhydride, 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo -3-furanyl Naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) Naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5,8-dimethyl-5- (tetrahydro-2,5-dioxo-3- Furanyl) -naphtho [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), among the compounds represented by the above formula (I), Formula (12)-(14)

Or a compound represented by the above formula (II):

Are preferable from the viewpoint of exhibiting good liquid crystal orientation, and particularly preferable are 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 1,3-dimethyl-1. , 2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2 -C] furan-1,3-dione, cis-3,7-dibutylcycloocta-1,5-diene-1,2,5,6-tetracarboxylic dianhydride, 1,2,4-tricarboxy Cyclopentyl acetic acid dianhydride, 3,5,6-tricarbonyl-2-carboxynorbornane-2: 3,5: 6-dianhydride, 1,3,3a, 4,5,9b-hexahydro-8-methyl- 5- (Tetrahi B-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 3-oxabicyclo [3.2.1] octane-2,4-dione-6 Examples include spiro-3 ′-(tetrahydrofuran-2 ′, 5′-dione) or a compound represented by the above formula (12).
Among other tetracarboxylic dianhydrides, preferred aliphatic tetracarboxylic dianhydrides or aromatic tetracarboxylic dianhydrides include butanetetracarboxylic dianhydride, pyromellitic dianhydride, 3, 3 ', 4,4'-benzophenone tetracarboxylic dianhydride, 2,2', 3,3'-biphenylsulfone tetracarboxylic dianhydride, 3,3 ', 4,4'-biphenylsulfone tetracarboxylic dianhydride An anhydride or 1,4,5,8-naphthalenetetracarboxylic dianhydride may be mentioned.
As other tetracarboxylic dianhydrides, it is preferable to use alicyclic tetracarboxylic dianhydrides.
When a specific tetracarboxylic dianhydride and another tetracarboxylic dianhydride are used in combination in the synthesis of the specific polyamic acid, the use ratio of the specific tetracarboxylic dianhydride is 50 with respect to the total tetracarboxylic dianhydrides. It is preferably at least mol%.

<Diamine>
The diamine used for the synthesis of the specific polyamic acid and / or its imidized polymer is at least one selected from the group consisting of the compounds represented by the above formulas (3) to (6) (hereinafter referred to as “specific diamine”). Is included.)
In the above formulas (3) to (6), examples of the linear alkyl group having 1 to 40 carbon atoms represented by R ^{1 to} R ⁴ include an n-hexyl group, an n-octyl group, an n-decyl group, n-dodecyl group, n-pentadecyl group, n-hexadecyl group, n-octadecyl group, n-eicosyl group and the like;
Examples of the branched alkyl group include 1-methylhexyl group, 1-ethylhexyl group, 2-methylhexyl group, 2-ethylhexyl group, 1-ethyloctyl group, 2-ethyloctyl group, 3-ethyloctyl group, 1 , 2-dimethylhexyl group, 1,2-diethylhexyl group, 1,2-dimethyloctyl group, 1,2-diethyloctyl group, 1-methyldecyl group, 1-ethyldecyl group, 2-methyldecyl group, 2-ethyldecyl group Such;
Examples of the cyclic alkyl group include a group obtained by removing one hydrogen atom from a cyclic alkane such as cyclobutane, cyclopentane, cyclohexane, cyclodecane, norbornene, bicyclooctane, bicycloundecane, and adamantane, and a cyclic alkyl group having a steroid skeleton. Can be mentioned respectively. Examples of the cyclic alkyl group having a steroid skeleton include a group obtained by removing a hydroxyl group from a steroid compound such as cholestanol.
As the linear, branched or cyclic alkenyl group having 4 to 40 carbon atoms represented by R ^{1 to} R ⁴ , one or more of the carbon-carbon bonds of the alkyl group exemplified above are doubled. The group which became a coupling | bonding can be mentioned. Among these, examples of the cyclic alkenyl group having a steroid skeleton include groups obtained by removing hydroxyl groups from steroid compounds such as cholesterol, lanosterol, and desmosterol.
As the specific diamine, a diamine in which the groups R ^{1 to} R ⁴ in the above formulas (3) to (6) are a cyclic alkyl group or a cyclic alkenyl group having a steroid skeleton, or
R ¹ is a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, or a linear, branched or cyclic alkenyl group having 4 to 20 carbon atoms, represented by the above formula (3). Diamine is preferred.
As the diamine used in the synthesis of the specific polyamic acid and / or its imidized polymer, only the specific diamine may be used, or the specific diamine and another diamine may be used in combination. Examples of other diamines that can be used here include aromatic diamines, aliphatic or alicyclic diamines, diamines having two primary amino groups in the molecule and nitrogen atoms other than the primary amino groups, and diaminoorganosiloxanes. Can be mentioned.

  Examples of the aromatic diamine include p-phenylenediamine, 2-methyl-1,4-phenylenediamine, 2-ethyl-1,4-phenylenediamine, 2,5-dimethyl-1,4-phenylenediamine, 2, 5-diethyl-1,4-phenylenediamine, 2,3,5,6-tetramethyl-1,4-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylethane 4,4′-diaminodiphenyl sulfide, 4,4′-diaminodiphenyl sulfone, 2,2′-dimethyl-4,4′-diaminobiphenyl, 3,3′-dimethyl-4,4′-diaminobiphenyl, 4, , 4′-diaminobenzanilide, 4,4′-diaminodiphenyl ether, 1,5-diaminonaphthalene, 3, -Dimethyl-4,4'-diaminobiphenyl, 5-amino-1- (4'-aminophenyl) -1,3,3-trimethylindane, 6-amino-1- (4'-aminophenyl) -1, 3,3-trimethylindane, 3,4'-diaminodiphenyl ether, 3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone, 4,4'-diaminobenzophenone, 2,2-bis [4- (4- Aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 2,2-bis [4- (4-Aminophenoxy) phenyl] sulfone, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminopheno) Ii) benzene, 1,3-bis (3-aminophenoxy) benzene, 9,9-bis (4-aminophenyl) -10-hydroanthracene, 2,7-diaminofluorene, 9,9-dimethyl-2,7 -Diaminofluorene, 9,9-bis (4-aminophenyl) fluorene, 4,4'-methylene-bis (2-chloroaniline), 2,2 ', 5,5'-tetrachloro-4,4'- Diaminobiphenyl, 2,2′-dichloro-4,4′-diamino-5,5′-dimethoxybiphenyl, 3,3′-dimethoxy-4,4′-diaminobiphenyl, 1,4,4 ′-(p- Phenyleneisopropylidene) bisaniline, 4,4 ′-(m-phenyleneisopropylidene) 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] -octafluorobiphenyl 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole and the like;

Examples of the aliphatic or alicyclic diamine include 1,1-metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, and nonamethylene. Diamine, 4,4-diaminoheptamethylenediamine, 1,4-diaminocyclohexane, isophoronediamine, tetrahydrodicyclopentadienylenediamine, hexahydro-4,7-methanoindanylenediethylenediamine, tricyclo [6.2.1 .0 ^2,7] - undecylenate range methyl diamine, 4,4'-methylenebis (cyclohexylamine) and the like;

Examples of the diamine having two primary amino groups in the molecule and a nitrogen atom other than the primary amino group include 2,3-diaminopyridine, 2,6-diaminopyridine, 3,4-diaminopyridine, 2, 4-diaminopyrimidine, 5,6-diamino-2,3-dicyanopyrazine, 5,6-diamino-2,4-dihydroxypyrimidine, 2,4-diamino-6-dimethylamino-1,3,5-triazine, 1,4-bis (3-aminopropyl) piperazine, 2,4-diamino-6-isopropoxy-1,3,5-triazine, 2,4-diamino-6-methoxy-1,3,5-triazine, 2,4-diamino-6-phenyl-1,3,5-triazine, 2,4-diamino-6-methyl-s-triazine, 2,4-diamino-1,3,5-triazine, , 6-Diamino-2-vinyl-s-triazine, 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-diaminopiperazine, 3,6-diaminoacridine, bis (4 -Aminophenyl) phenylamine and the like;
Examples of the diaminoorganosiloxane include the following formula (16):

(Here, R ¹¹ represents a hydrocarbon group having 1 to 12 carbon atoms, and a plurality of R ¹¹ may be the same or different, p is an integer of 1 to 3, and q is 1 to 20) Is an integer.)
And the like can be mentioned respectively.
These other diamines can be used alone or in combination of two or more.

  Among these other diamines, p-phenylenediamine, 2-methyl-1,4-phenylenediamine, 2-ethyl-1,4-phenylenediamine, 2,5-dimethyl-1,4-phenylenediamine, 2,5 -Diethyl-1,4-phenylenediamine, 2,3,5,6-tetramethyl-1,4-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfide, 2,2'- Dimethyl-4,4′-diaminobiphenyl, 1,5-diaminonaphthalene, 2,7-diaminofluorene, 9,9-dimethyl-2,7-diaminofluorene, 4,4′-diaminodiphenyl ether, 2,2-bis [4- (4-Aminophenoxy) phenyl] propane, 9,9-bis (4-aminophenyl) fluorene, 2,2-bis 4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4 ′-(p-phenylenediisopropylidene) bisaniline, 4,4 ′-( m-phenylenediisopropylidene) bisaniline, 1,4-cyclohexanediamine, 4,4′-methylenebis (cyclohexylamine), 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-amino) Phenoxy) biphenyl, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminoacridine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, N-ethyl-3,6-diaminocarbazole or N-phenyl-3,6- Aminocarbazole is preferred, more preferably p-phenylenediamine, 2-methyl-1,4-phenylenediamine, 2-ethyl-1,4-phenylenediamine, 2,5-dimethyl-1,4-phenylenediamine, 2, 5-diethyl-1,4-phenylenediamine or 2,3,5,6-tetramethyl-1,4-phenylenediamine.

  In order to further improve the pretilt angle developability of the liquid crystal aligning agent of the present invention, in addition to the specific diamine, instead of the other diamine that is optionally used, or together with the other diamine, the following formula ( Q-1)

(Wherein X ² is a single bond, —O—, —CO—, —COO—, —OCO—, —NHCO—, —CONH—, —S—, or an arylene group, and R ¹² has 10 to 10 carbon atoms. 20 alkyl groups, monovalent organic groups having an alicyclic skeleton having 4 to 40 carbon atoms, or monovalent organic groups having a fluorine atom having 6 to 20 carbon atoms.)
And a compound represented by the following formula (Q-2)

(Wherein X ³ is a single bond, —O—, —CO—, —COO—, —OCO—, —NHCO—, —CONH—, —S— or an arylene group, and R ¹³ has 4 to 4 carbon atoms. It is a divalent organic group having 40 alicyclic skeletons.)
You may use at least 1 sort (s) selected from the group which consists of a compound represented by these. These can be used alone or in combination of two or more.

In the formula (Q-1), examples of the alkyl group having 10 to 20 carbon atoms represented by R ¹² include an n-decyl group, an n-dodecyl group, an n-pentadecyl group, an n-hexadecyl group, and an n-octadecyl group. Group, n-eicosyl group and the like.
Examples of the monovalent or divalent organic group having an alicyclic skeleton having 4 to 40 carbon atoms represented by R ¹² in the formula (Q-1) and R ¹³ in the formula (Q-2) include, for example, cyclobutane. , Cyclopentane, cyclohexane, cyclodecane and other cycloalkane-derived alicyclic skeleton groups; cholesterol, cholestanol and other steroid skeleton groups; norbornene, adamantane and other bridged alicyclic skeleton groups It is done. Among these, a group having a steroid skeleton is particularly preferable. In the organic group having the alicyclic skeleton, some or all of the hydrogen atoms may be substituted with a halogen atom, preferably a fluorine atom, a fluoroalkyl group, preferably a trifluoromethyl group.
Examples of the group having 6 to 20 carbon atoms represented by R ¹² in the formula (Q-1) include 6 to 20 carbon atoms such as an n-hexyl group, an n-octyl group, and an n-decyl group. 20 linear alkyl groups; alicyclic hydrocarbon groups having 6 to 20 carbon atoms such as cyclohexyl group and cyclooctyl group; organics such as aromatic hydrocarbon groups having 6 to 20 carbon atoms such as phenyl group and biphenyl group Examples include a group in which part or all of the hydrogen atoms in the group are substituted with a fluoroalkyl group such as a fluorine atom or a trifluoromethyl group.
X ² in the above formula (Q-1) and X ³ in the above formula (Q-2) are a single bond, —O—, —CO—, —COO—, —OCO—, —NHCO—, —CONH, respectively. Although it is-, -S- or an arylene group, examples of the arylene group include a phenylene group, a tolylene group, a biphenylene group, and a naphthylene group. X ² and X ³ are each particularly preferably a group represented by —O—, —COO— or —OCO—.

  Preferable specific examples of the diamine having the group represented by the formula (Q-1) include dodecanoxy-2,4-diaminobenzene, pentadecanoxy-2,4-diaminobenzene, hexadecanoxy-2,4-diaminobenzene, octadecanoxy. -2,4-diaminobenzene or the following formulas (17) to (26)

The compound represented by these can be mentioned. Preferable specific examples of the diamine having a group represented by the above formula (Q-2) include the following formulas (27) to (29).

Among these, particularly preferred are compounds represented by the above formula (17), (18), (23), (24) or (27).
When the specific diamine and other diamine and / or the diamine represented by the above formula (Q-1) or (Q-2) are used in combination in the synthesis of the specific polyamic acid, the use ratio of the specific diamine is based on the total diamine. It is preferably 1 mol% or more, more preferably 5 mol%.

<Synthesis of specific polyamic acid>
Next, a method for synthesizing a specific polyamic acid that can be contained in the liquid crystal aligning agent of the present invention will be described.
The specific polyamic acid comprises the above-mentioned specific tetracarboxylic dianhydride and optionally other tetracarboxylic dianhydride, the specific diamine and optionally other diamine, preferably in an organic solvent, preferably from −20 ° C. to It can be synthesized by reacting at a temperature of 150 ° C., more preferably 0 to 100 ° C., and preferably 0.5 to 72 hours.
The proportion of tetracarboxylic dianhydride and diamine used in the synthesis reaction of the specific polyamic acid is such that the acid anhydride group of tetracarboxylic dianhydride is 0.5 to 2 with respect to 1 equivalent of amino group of diamine. The ratio which becomes an equivalent is preferable, More preferably, it is a ratio which becomes 0.7-1.2 equivalent.
Here, the organic solvent is not particularly limited as long as it can dissolve the specific polyamic acid to be synthesized. For example, 1-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, 3 Amido solvents such as -butoxy-N, N-dimethylpropanamide, 3-methoxy-N, N-dimethylpropanamide, 3-hexyloxy-N, N-dimethylpropanamide, dimethyl sulfoxide, γ-butyrolactone, tetramethyl Examples include aprotic polar solvents such as urea and hexamethylphosphortriamide; and phenolic solvents such as m-cresol, xylenol, phenol and halogenated phenol. Further, the amount (α) of the organic solvent used is such that the ratio (monomer concentration) of the total amount (β) of tetracarboxylic dianhydride and diamine compound to the total amount (α + β) of the reaction solution is 0.1 to 30% by weight. Such an amount is preferred.

As the organic solvent, alcohols, ketones, esters, ethers, halogenated hydrocarbons, hydrocarbons, and the like, which are poor solvents for the specific polyamic acid, can be used in combination as long as the generated specific polyamic acid does not precipitate. Specific examples of the poor solvent include, for example, methanol, ethanol, isopropanol, cyclohexanol, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, ethylene glycol. Monomethyl ether, ethyl lactate, butyl lactate, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, diethyl oxalate, diethyl malonate, Diethyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether Ethylene glycol-n-butyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, 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, Examples include 2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene, hexane, heptane, octane, benzene, toluene, xylene, isoamylpropionate, isoamylisobutyrate, and diisopentyl ether. Can.
When the organic solvent and the poor solvent are used in combination, the use ratio of the poor solvent is preferably 50% by weight or less, more preferably 20% by weight or less, and further 10% by weight with respect to the total amount of the organic solvent and the poor solvent. % Or less is preferable.
As described above, a reaction solution obtained by dissolving the specific polyamic acid is obtained. This reaction solution may be used as it is for the preparation of the liquid crystal aligning agent, may be used for the preparation of the liquid crystal aligning agent after isolating the specific polyamic acid contained in the reaction solution, or the isolated specific polyamic acid may be used. You may use for preparation of a liquid crystal aligning agent, after refine | purifying. The specific polyamic acid is isolated by pouring the reaction solution into a large amount of poor solvent to obtain a precipitate, and drying the precipitate under reduced pressure, or by distilling the reaction solution under reduced pressure with an evaporator. Can do. In addition, the specific polyamic acid can be purified by a method in which the specific polyamic acid is dissolved again in an organic solvent and then precipitated in a poor solvent, or a method in which the step of distilling off with an evaporator under reduced pressure is performed once or several times. .

<Method for synthesizing imidized polymer of specific polyamic acid>
Next, the synthesis | combining method of the imidation polymer of the specific polyamic acid which the liquid crystal aligning agent of this invention can contain is demonstrated.
The imidized polymer of the specific polyamic acid can be synthesized by dehydrating and ring-closing part or all of the amic acid structure of the specific polyamic acid. The imidized polymer that can be used in the present invention may be a completely imidized product in which all of the amic acid structure of the specific polyamic acid is dehydrated and closed, or the number of amic acid structures and the number of imide rings. The ratio of the number of imide rings to the total (hereinafter also referred to as “imidation rate”) may be less than 100% and partially dehydrated and closed. The imidation ratio of the imidized polymer of the specific polyamic acid is preferably 40 mol% or more, more preferably 50 mol% or more. By using an imidized polymer having an imidization ratio of 40 mol% or more, it is possible to further shorten the afterimage erasing time of the obtained liquid crystal alignment film. The imidization ratio can be calculated by the following equation (1) from ^{1 H-NMR} of the imidized polymer.

Imidation ratio (%) = (1−A1 / A2 × α) × 100 (1)

(In the formula (1), A1 is a peak area in the vicinity of 10 ppm chemical shift derived from the proton of the NH group, A2 is a peak area in the vicinity of 7-8 ppm chemical shift derived from the aromatic proton, and α is imidization. (This is the ratio of the number of aromatic protons to one proton of the NH group in the polyamic acid before the reaction.)

The dehydration cyclization reaction of the specific polyamic acid can be carried out by (i) a method of heating the specific polyamic acid or (ii) dissolving the specific polyamic acid in an organic solvent, adding a dehydrating agent and a dehydration ring closure catalyst to this solution, and heating as necessary. It is done by the method to do.
The reaction temperature in the method (i) of heating the specific polyamic acid is preferably 50 to 200 ° C, more preferably 60 to 170 ° C. When the reaction temperature is less than 50 ° C., the dehydration ring-closing reaction does not proceed sufficiently, and when the reaction temperature exceeds 200 ° C., the molecular weight of the imidized polymer obtained may decrease. The reaction time is preferably 1 to 120 hours, more preferably 2 to 30 hours.
On the other hand, in the method (ii) of adding a dehydrating agent and a dehydrating ring-closing catalyst to the solution of the specific polyamic acid, as the dehydrating agent, for example, an acid anhydride such as acetic anhydride, propionic anhydride, or trifluoroacetic anhydride is used. be able to. Although the usage-amount of a dehydrating agent is based on the desired imidation rate, it is preferable to set it as 0.01-20 mol with respect to 1 mol of repeating units of a specific polyamic acid. As the dehydration ring closure catalyst, for example, tertiary amines such as pyridine, collidine, lutidine, and triethylamine can be used. However, it is not limited to these. The amount of the dehydration ring-closing catalyst used is preferably 0.01 to 10 mol with respect to 1 mol of the dehydrating agent used. The imidation rate can be increased as the amount of the above dehydrating agent and dehydrating ring-closing agent increases. Examples of the organic solvent used for the dehydration ring closure reaction include the organic solvents exemplified as those used for the synthesis of the specific polyamic acid. The reaction temperature of the dehydration ring closure reaction is preferably 0 to 180 ° C, more preferably 10 to 150 ° C. The reaction time is preferably 0.5 to 30 hours, more preferably 2 to 10 hours.

  The imidized polymer obtained in the above method (i) may be used for the preparation of a liquid crystal aligning agent as it is, or may be used for the preparation of a liquid crystal aligning agent after purifying the obtained imidized polymer. . On the other hand, in the method (ii), a reaction solution containing an imidized polymer is obtained. This reaction solution may be directly used for the preparation of the liquid crystal aligning agent, or may be used for the preparation of the liquid crystal aligning agent after removing the dehydrating agent and the dehydrating ring-closing catalyst from the reaction solution. After separating, it may be used for preparing a liquid crystal aligning agent, or the isolated imidized polymer may be purified and then used for preparing a liquid crystal aligning agent. In order to remove the dehydrating agent and the dehydrating ring-closing catalyst from the reaction solution, for example, a method such as solvent replacement can be applied. Isolation and purification of the imidized polymer can be performed by carrying out operations similar to those described above as methods for isolating and purifying the specific polyamic acid, respectively.

<End-modified polymer>
The specific polyamic acid or imidized polymer thereof used in the present invention may be a terminal-modified polymer having a controlled molecular weight. By using a terminal-modified polymer, the coating properties of the liquid crystal aligning agent can be improved without impairing the effects of the present invention. Such a terminal-modified polymer can be synthesized by adding an acid monoanhydride, a monoamine compound, a monoisocyanate compound or the like to the reaction system when synthesizing a specific polyamic acid. Here, as the acid monoanhydride, for example, maleic anhydride, phthalic anhydride, itaconic anhydride, n-decyl succinic anhydride, n-dodecyl succinic anhydride, n-tetradecyl succinic anhydride , N-hexadecyl succinic anhydride and the like. Examples of the monoamine compound include aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, n-undecylamine, n -Dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecylamine, n-octadecylamine, n-eicosylamine . Examples of the monoisocyanate compound include phenyl isocyanate and naphthyl isocyanate.
The molecular weight regulator is preferably used in an amount of 20 parts by weight or less, more preferably 10 parts by weight or less, based on 100 parts by weight of the total of tetracarboxylic dianhydride and diamine used in the synthesis of the specific polyamic acid. .

<Solution viscosity of polymer>
The specific polyamic acid or its imidized polymer obtained as described above preferably has a solution viscosity of 20 to 800 mPa · s, when it is made into a solution having a concentration of 10% by weight, and preferably 30 to 500 mPa · s. More preferably, it has a solution viscosity of s.
The solution viscosity (mPa · s) of the above polymer is E for a polymer solution having a concentration of 10% by weight prepared using a good solvent for the polymer (for example, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.). It is a value measured at 25 ° C. using a mold rotational viscometer.

<Other polymers>
In the liquid crystal aligning agent of the present invention, as long as the effects of the present invention are not impaired, at least a part of the specific polyamic acid or imidized polymer thereof is selected from the group consisting of other polyamic acids and imidized polymers thereof. It can be replaced with one kind (hereinafter referred to as “other polymer”).
The other polymer is not particularly limited as long as it is a polyamic acid other than the specific polyamic acid or an imidized polymer thereof, but by reaction of the other tetracarboxylic dianhydride with another diamine. It is preferable that it is the polyamic acid obtained or its imidized polymer. As other tetracarboxylic dianhydrides used here, alicyclic tetracarboxylic dianhydrides or aromatic tetracarboxylic dianhydrides are preferable, in particular 1,2,3,4-cyclobutanetetracarboxylic acid. A dianhydride or pyromellitic dianhydride is preferred. As other diamines used here, aromatic diamines are preferable, and 4,4-diaminodiphenylmethane is particularly preferable.
The synthesis of such other polymer is carried out by synthesizing a specific polyamic acid and its imidized polymer by using other tetracarboxylic dianhydride and other diamine in place of the specific tetracarboxylic dianhydride and the specific diamine. The same can be done.
When the liquid crystal aligning agent of the present invention contains another polymer, the use ratio of the other polymer is preferably relative to the total amount of the specific polyamic acid and its imidized polymer and the other polymer. Is 80% by weight or less, more preferably 60% by weight or less.

<Organic silicon compound>
The liquid crystal aligning agent of the present invention further contains a compound represented by the above formula (7) (hereinafter referred to as “organosilicon compound”).
Specific examples of the methylene group or polymethylene group of R ⁵ of the group X ¹ in the above formula (7) include, for example, —CH ₂ —, — (CH ₂ ) ₂ —, — (CH ₂ ) ₃ —, — ( CH ₂ ) ₄ — and the like can be mentioned. As the alkyl group for R ⁶ , an alkyl group having 1 to 10 carbon atoms is preferable.
The use ratio of the organosilicon compound in the liquid crystal aligning agent of the present invention is the total amount of the specific polyamic acid and its imidized polymer (hereinafter referred to as “total amount of polymer”. In this case, the “total amount of polymer” refers to the total amount of the specific polyamic acid, its imidized polymer and other polymers. The amount is preferably 0.01 to 3 parts by weight, more preferably 0.1 to 2 parts by weight. By setting the use ratio within this range, a liquid crystal aligning agent that can form a liquid crystal aligning film having excellent printability and excellent electrical characteristics can be obtained.

<Other additives>
The liquid crystal aligning agent of the present invention contains at least one selected from the group consisting of the above specific polyamic acid and its imidized polymer, an organic silicon compound, and a solvent described later as essential components, but the effects of the present invention are impaired. Other additives may be contained within the range. Examples of such other additives include compounds having two or more epoxy groups in the molecule, and functional silane compounds.
The compound having two or more epoxy groups in the molecule (hereinafter referred to as “epoxy compound”) may be added in order to further improve the printability of the liquid crystal alignment film obtained from the liquid crystal aligning agent of the present invention. it can. Specific examples of such epoxy compounds include, for example, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1, 6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentylglycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, N, N, N ′, N′-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ′, N′-tetraglycidyl-4,4 '-Diaminodiphenylmethane, 3- (N-allyl-N-glycidyl) aminopropyltrimethoxysilane, 3- (N, N-diglycidyl) aminopropyltrimethoxysilane, N, N, -diglycidyl-benzylamine, N, N- Diglycidyl-aminomethylcyclohexane and the like can be mentioned as preferable ones. The proportion of the epoxy compound used in the liquid crystal aligning agent of the present invention is preferably 50 parts by weight or less, more preferably 0.1 to 40 parts by weight with respect to 100 parts by weight of the total amount of the polymer. It is preferable that it is 1-30 weight part.

  The said functional silane compound can be added from a viewpoint which improves the adhesiveness with respect to the board | substrate of the liquid crystal aligning film obtained from the liquid crystal aligning agent of this invention. Specific examples of such functional silane compounds include, for example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-amino Ethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3 -Aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl -1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diaza Nonyl acetate, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane N-bis (oxyethylene) -3-aminopropyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, and the like. The blending ratio of these functional silane compounds is preferably 10 parts by weight or less, more preferably 0.01 to 5 parts by weight with respect to 100 parts by weight of the total amount of the polymer.

<Solvent>
As a solvent which the liquid crystal aligning agent of this invention contains, an organic solvent is preferable and can mention the solvent illustrated as what is used for the synthesis reaction of a specific polyamic acid. Moreover, the poor solvent illustrated as what can be used together in the case of the synthesis reaction of specific polyamic acid can also be selected suitably, and can be used together.
Particularly preferable organic solvents used in the liquid crystal aligning agent of the present invention include, for example, 1-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N, N-dimethylformamide, 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 ethyl ether, ethylene glycol-n- Propyl ether, ethylene glycol-i-propyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol Dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, 3-butoxy-N, N-dimethylpropanamide, 3-methoxy-N, N-dimethylpropane Examples thereof include amide, 3-hexyloxy-N, N-dimethylpropanamide, diethyl carbitol, ethyl carbitol acetate, butyl carbitol, triethylene glycol dimethyl ether, isoamyl isobutyrate, and diisopentyl ether. These can be used alone or in admixture of two or more. A particularly preferable solvent composition is a composition obtained by combining the above-mentioned solvents, wherein no polymer is precipitated in the aligning agent, and the surface tension of the aligning agent is in the range of 25 to 40 mN / m. It is.

<Liquid crystal aligning agent>
Although the liquid crystal aligning agent of this invention has at least 1 sort (s) selected from the group which consists of the said specific polyamic acid and its imidated polymer, an organic silicon compound, and a solvent as an essential component, it optionally contains another additive. Preferably, the liquid crystal aligning agent is prepared as a solution state in which components other than the solvent are dissolved in the solvent.
The solid content concentration (the value obtained by dividing the total weight of components other than the solvent in the liquid crystal aligning agent by the total weight of the liquid crystal aligning agent) in the liquid crystal aligning agent of the present invention is selected in consideration of viscosity, volatility, and the like. The range is preferably 1 to 10% by weight. That is, the liquid crystal aligning agent of the present invention is applied to the substrate surface to form a coating film that becomes a liquid crystal alignment film. When the solid content concentration is less than 1% by weight, the coating film thickness is On the other hand, if the solid content concentration exceeds 10% by weight, the film thickness of the coating film becomes excessive and a good liquid crystal alignment film can be obtained. In addition, the viscosity of the liquid crystal aligning agent may increase, resulting in poor coating characteristics.
The particularly preferable solid content concentration range varies depending on the method used when the liquid crystal aligning agent is applied to the substrate. For example, when the spinner method is used, the range of 1.5 to 4.5% by weight is particularly preferable. In the case of the printing method, it is particularly preferable that the solid content concentration is in the range of 3 to 9% by weight, and thereby the solution viscosity is in the range of 12 to 50 mPa · s. In the case of the inkjet method, it is particularly preferable that the solid content concentration is in the range of 1 to 5% by weight, and thereby the solution viscosity is in the range of 3 to 15 mPa · s.
The temperature at the time of preparing the liquid crystal aligning agent of this invention becomes like this. Preferably it is 0 to 200 degreeC, More preferably, it is 20 to 60 degreeC.

<Liquid crystal display element>
The liquid crystal display element of the present invention comprises a liquid crystal alignment film obtained from the liquid crystal aligning agent of the present invention obtained as described above.
The liquid crystal display element of the present invention can be produced, for example, by the following steps (1) to (3).
(1) The liquid crystal aligning agent of the present invention is applied to one surface of a substrate provided with a patterned transparent conductive film by an appropriate application method such as an offset printing method, a spin coating method, or an ink jet printing method, and then applied. A coating film is formed by heating the surface. Here, as the substrate, for example, a glass such as float glass or soda glass; a transparent substrate made of a plastic such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, or polycarbonate can be used. As a transparent conductive film provided on one surface of the substrate, an NESA film (registered trademark of PPG, USA) made of tin oxide (SnO ₂ ), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ), etc. For patterning these transparent conductive films, a method by photo-etching or a method using a mask in advance when forming the transparent conductive film is used. When applying the liquid crystal aligning agent, in order to further improve the adhesion between the substrate surface and the transparent conductive film and the coating film, a functional silane compound, a functional titanium compound or the like is applied in advance to the surface of the substrate. It may be left. The heating temperature after application of the liquid crystal aligning agent is preferably 80 to 300 ° C, more preferably 120 to 250 ° C. The heating time is preferably 5 to 200 minutes, more preferably 10 to 100 minutes. In addition, although the liquid crystal aligning agent of this invention forms the coating film used as an alignment film by removing an organic solvent after application | coating, when the liquid crystal aligning agent of this invention contains the polymer which has an amic acid structure, By further heating after the formation of the coating film, dehydration and ring closure of the amic acid structure can be advanced to obtain a more imidized coating film.
The film thickness of the formed coating film is preferably 0.001-1 μm, more preferably 0.005-0.5 μm.

(2) Next, the coating surface formed as described above is usually rubbed in a fixed direction with a roll wound with a cloth made of fibers such as nylon, rayon, and cotton. Thereby, the orientation ability of liquid crystal molecules is imparted to the coating film to form a liquid crystal orientation film. Further, the liquid crystal alignment film formed by the liquid crystal aligning agent of the present invention is disclosed in, for example, Patent Document 2 (Japanese Patent Laid-Open No. 6-222366) and Patent Document 3 (Japanese Patent Laid-Open No. 6-281937). A resist film is formed on the surface of the liquid crystal alignment film that has been subjected to a treatment that changes the pretilt angle by partially irradiating ultraviolet rays, or a rubbing treatment as disclosed in Patent Document 4 (JP-A-5-107544). Is partially formed, and after the rubbing treatment is performed in a direction different from the previous rubbing treatment, the resist film is removed, and a treatment for changing the liquid crystal orientation ability of the liquid crystal orientation film is performed. It is possible to improve the visibility characteristics.

(3) Two substrates on which a liquid crystal alignment film is formed as described in the above (1) or (2) are produced, and two sheets are rubbed so that the rubbing directions in the respective liquid crystal alignment films are orthogonal or antiparallel. The substrates are arranged facing each other through a gap (cell gap), the peripheral portions of the two substrates are bonded together using a sealant, and liquid crystal is injected and filled in the cell gap defined by the substrate surface and the sealant, The injection hole is sealed to constitute a liquid crystal cell. A polarizing plate is disposed on the outer surface of the liquid crystal cell, that is, on the other surface side of each substrate constituting the liquid crystal cell, and the polarization direction thereof coincides with or is orthogonal to the rubbing direction of the liquid crystal alignment film formed on one surface of the substrate. A liquid crystal display element is obtained by pasting together. Here, as the sealing agent, for example, an epoxy resin containing a curing agent and aluminum oxide spheres as a spacer can be used. Examples of the liquid crystal include nematic liquid crystal and smectic liquid crystal. Among them, nematic liquid crystal is preferable. For example, Schiff base liquid crystal, azoxy liquid crystal, biphenyl liquid crystal, phenyl cyclohexane liquid crystal, ester liquid crystal, terphenyl liquid crystal. Liquid crystals, biphenylcyclohexane liquid crystals, pyrimidine liquid crystals, dioxane liquid crystals, bicyclooctane liquid crystals, cubane liquid crystals, and the like can be used. In addition, cholesteric liquid crystals such as cholestyl chloride, cholesteryl nonate, and cholesteryl carbonate; chiral agents such as those sold under the trade names “C-15” and “CB-15” (manufactured by Merck) : Ferroelectric liquid crystal such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate may be added and used.
As a polarizing plate bonded to the outer surface of the liquid crystal cell, a polarizing film or an H film in which a polarizing film called an “H film” that absorbs iodine while stretching and aligning polyvinyl alcohol is sandwiched between protective films of cellulose acetate The polarizing plate which consists of itself can be mentioned.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.
The liquid crystal aligning agents prepared in the following examples and comparative examples were evaluated according to the following methods.
[Printability evaluation]
A 127 mm (D) × 127 mm (W) × 1.1 mm (H) glass substrate having an ITO film formed as a transparent electrode on the entire surface of one side was prepared, and a printing machine for applying a liquid crystal alignment film (Japanese photograph) The liquid crystal aligning agent having a solid content concentration of 5% by weight obtained in each Example or Comparative Example was filtered through a microfilter having a pore size of 0.2 μm using a printing Co., Ltd. type name “Angstromer S-40L”. Then, it was applied to the transparent electrode surface. After the coating, the solvent was removed by a hot plate close-contact type pre-dryer set at 80 ° C., and then heated at 200 ° C. for 10 minutes, so that a coating with a film thickness of about 0.06 μm was formed on the glass substrate with the ITO film. A film was formed. This film is observed visually and under a microscope. When there is no pinhole or coating unevenness, “excellent”, when pinhole or coating unevenness (film thickness unevenness, etc.) is slightly observed, “good”, pinhole or When coating unevenness was observed remarkably, it was judged as “bad”.

[Evaluation of voltage holding ratio]
Using a glass substrate on which a patterned ITO electrode having a thickness of about 1 mm is formed on one side, and the liquid crystal aligning agent having a solid content concentration of 3.5% by weight obtained in each example or comparative example as the liquid crystal aligning agent. Except for the use, a pair (two) of glass substrates having a coating film with a film thickness of about 0.06 μm was prepared in the same manner as in the above [evaluation of printability].
Next, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm was applied to the outer edges of the pair of transparent electrodes / transparent substrate having the liquid crystal alignment film of the liquid crystal alignment film coated substrate, leaving a liquid crystal injection port. After that, the liquid crystal alignment film surfaces were overlapped so as to face each other and pressed to cure the adhesive. Next, a nematic liquid crystal (negative type, MLC-6608, MLC-6608) is filled between the substrates through the liquid crystal injection port, and then the liquid crystal injection port is sealed with an acrylic photo-curing adhesive, and both sides outside the substrate are sealed. A liquid crystal display element was produced by laminating a polarizing plate on the substrate.
A voltage of 5 V was applied to the liquid crystal display element at room temperature for 60 microseconds in application time of 16.7 milliseconds, and the voltage holding ratio after 16.7 milliseconds from release of application was measured. The measuring apparatus used was VHR-1 manufactured by Toyo Corporation.

[Evaluation of burn-in]
A liquid crystal display device was produced in the same manner as in [Evaluation of voltage holding ratio] except that a glass substrate having an ITO film having a pattern as shown in FIG. 1 was used on one side.
In this liquid crystal display element, a DC voltage of 6.0 V was applied to the electrode A and a DC voltage of 0.5 V was applied to the electrode B at room temperature for 24 hours. After removing the voltage, a DC voltage of 0.1 to 5.0 V was applied to each of the electrodes A and B in increments of 0.1 V, and the burn-in characteristics were determined based on the luminance difference between the electrodes A and B at each voltage. That is, it was determined that the burn-in characteristic was bad when the luminance difference was large. “O” indicates that no burn-in is observed (no difference in luminance between the two electrodes is observed), and “B” indicates that the image is weakly burned (the luminance difference between the two electrodes is moderate). Δ.

Synthesis example <Synthesis example of specific diamine>
Synthesis Example A-1 (Synthesis of 1- (3,5-diaminophenyl) -3-octadecylsuccinimide)
In a 300 mL three-necked flask replaced with nitrogen gas, 12.81 g (0.07 mol) of 3,5-dinitroaniline and 70 mL of acetic acid were added, and the solid was dissolved by stirring while circulating nitrogen gas. To this, 24.64 g (0.07 mol) of octadecyl succinic anhydride was added and reacted under reflux for 20 h under nitrogen. After cooling the reaction solution to room temperature, 70 mL of methanol was added and allowed to stand overnight. The precipitated solid was separated by filtration, washed with methanol and dried to obtain 30 g (yield 83%) of 1- (3,5-dinitrophenyl) -3-octadecylsuccinimide.
Next, in a 500 mL flask substituted with nitrogen gas, 30 g (0.058 mol) of 1- (3,5-dinitrophenyl) -3-octadecylsuccinimide synthesized above, 100 mL of ethanol, 100 mL of tetrahydrofuran (THF), and palladium for the reduction catalyst Carbon (Pd / C) 25g was added and it stirred at 70 degreeC for 1 hour. To this was added 42.5 mL (43.75 g) of hydrazine monohydrate, and the mixture was heated to reflux for 6 hours for reaction. Pd / C was filtered off, and the filtrate was concentrated on a rotary evaporator. The obtained crude product was dissolved by heating in N-methyl-2-pyrrolidone, then cooled and recrystallized, and 14.6 g of 1- (3,5-diaminophenyl) -3-octadecylsuccinimide which was the target product. (0.032 mol, yield 55%) was obtained.

Synthesis Example A-2 (Synthesis of 1- (3,5-diaminophenyl) -3-dodecylsuccinimide)
1- (3) In the same manner as in Synthesis Example A-1, except that 18.76 g (0.07 mol) of dodecyl succinic anhydride was used instead of 24.64 g (0.07 mol) of octadecyl succinic anhydride. , 5-diaminophenyl) -3-dodecylsuccinimide (11 g, 0.030 mol, yield 51%) was obtained.

Synthesis Example A-3 (Synthesis of 1- (3,5-diaminophenyl) -3-heptadecyl-4-methylmaleimide)
In a nitrogen-substituted 2,000 mL three-necked flask, 31.5 g (0.25 mol) of dimethylmaleic anhydride, 89.0 g (0.5 mol) of N-bromosuccinimide, 1.0 g (4.15 mmol) of benzoyl peroxide and tetrachloride 1,500 mL of carbon was added and heated to reflux for 5 h. The reaction solution was cooled to room temperature, allowed to stand at room temperature overnight, and then filtered. After the filtrate was washed with water, the organic layer was concentrated on a rotary evaporator. The obtained crude oily product was distilled under high vacuum (120 to 125 ° C./2 mmHg), and 20.0 g (0.1 mol, yield 39) of 3-bromomethyl-4-methylmaleic anhydride as an intermediate was obtained. %).
Next, in a 2,000 mL three-necked flask replaced with argon gas, 16.4 g (80 mmol) of 3-bromomethyl-4-methylmaleic anhydride obtained above, 1.52 g (8.0 mmol) of copper iodide, After adding 400 mL of diethyl ether and 160 mL of HMPA (hexamethylphosphoric triamide), the mixture was cooled to −5 to 0 ° C. under argon gas flow. While stirring this mixed solution, a solution prepared by dissolving 400 mmol of hexadecylmagnesium bromide separately prepared in 400 mL of diethyl ether was added dropwise over about 20 minutes. The mixture was returned to room temperature and further stirred for 8 h. Next, after diluting with 600 mL of diethyl ether, 600 mL of 4N-sulfuric acid was added to make the solution acidic. The separated aqueous layer was further washed with 600 mL of diethyl ether, and the organic layers were combined. The organic layer was washed with water and dehydrated with sodium sulfate, and then the solution was concentrated on a rotary evaporator to obtain an oily crude product. This crude product was purified on a silica gel column using petroleum ether / ethyl acetate (19: 1) mixed solution as a developing solvent, and 14.0 g of 3-heptadecyl-4-methylmaleic anhydride (0.04 mol yield). 50%).

Next, 6.4 g (0.035 mol) of 3,5-dinitroaniline and 35 mL of acetic acid were added to a 200 mL three-neck flask purged with nitrogen gas. Stirring while flowing nitrogen gas, the solid matter was dissolved. To this was added 12.3 g (0.035 mol) of 3-heptadecyl-4-methylmaleic anhydride obtained above, and the mixture was refluxed for 20 hours under nitrogen. After cooling the reaction solution to room temperature, 35 mL of methanol was added and allowed to stand overnight. The solid was separated by filtration, washed with methanol, and dried to obtain 14.6 g (0.029 mol yield 81%) of 1- (3,5-dinitrophenyl) -3-heptadecyl-4-methylmaleimide.
Next, 13.4 g (0.026 mol) of 1- (3,5-dinitrophenyl) -3-heptadecyl-4-methylmaleimide, ethanol 50 mL, THF 50 mL, and reduction catalyst Pd / C 12 were placed in a 300 mL flask purged with nitrogen gas. 0.5 g was added and stirred at 70 ° C. for 1 hour. Next, 19 mL (19.6 g) of hydrazine monohydrate was added, and the mixture was heated to reflux for 6 hours for reaction. Pd / C was filtered off, and the filtrate was concentrated on a rotary evaporator. The obtained crude product was recrystallized by heating and dissolving with N-methyl-2-pyrrolidone and cooling to give 1- (3,5-diaminophenyl) -3-heptadecyl-4-methyl which is the target product. 6.6 g of maleimide (0.015 mol yield 56%) was obtained.

Synthesis Example A-4 (Synthesis of 1- (3,5-diaminophenyl) -3-hexadecanoxymethyl-4-methylmaleimide)
After adding 3.81 g (0.07 mol) of 3,5-dinitroaniline and 70 mL of acetic acid to a 300 mL three-necked flask purged with nitrogen, the solid was dissolved by stirring while circulating nitrogen gas. To this was added 14.35 g (0.07 mol) of 3- (bromomethyl) -4-methylmaleic anhydride synthesized in the same manner as the intermediate of Synthesis Example A-3, and the mixture was refluxed for 20 hours under nitrogen. After cooling the reaction solution to room temperature, 70 mL of methanol was added and allowed to stand overnight. The solid content was separated by filtration, washed with methanol, and dried to obtain 18.9 g (0.051 mol yield 73%) of 1- (3,5-dinitrophenyl) -3-bromomethyl-4-methylmaleimide.
Next, 18.1 g (0.049 mol) of 1- (3,5-dinitrophenyl) -3-bromomethyl-4-methylmaleimide and 12.9 g of 1-hexadecanol sodium salt were added to a nitrogen-substituted 500 mL three-necked flask. 0.049 mol) and 100 mL of dimethyl sulfoxide were added, and the mixture was stirred and reacted at 100 ° C. for 10 hours. After cooling the reaction solution to room temperature, 70 mL of methanol was added and allowed to stand overnight. The solid content was filtered off, washed with methanol and dried, and 20.8 g of 1- (3,5-dinitrophenyl) -3-hexadecanoxymethyl-4-methylmaleimide (0.039 mol yield 80%) Got.
Next, 13.8 g (0.026 mol) of 1- (3,5-dinitrophenyl) -3-hexadecanoxymethyl-4-methylmaleimide, 50 mL of ethanol, 50 mL of THF, and reduction catalyst Pd were added to a 300 mL flask purged with nitrogen gas. / C 12.5g was added and it stirred at 70 degreeC for 1 hour. Thereafter, 19 mL (19.6 g) of hydrazine monohydrate was added, and the mixture was heated to reflux for 6 hours for reaction. Pd / C was filtered off, and the filtrate was concentrated on a rotary evaporator. The resulting crude product was recrystallized by heating and dissolving with N-methyl-2-pyrrolidone and cooling to give 1- (3,5-diaminophenyl) -3-hexadecanoxymethyl which is the target product. Obtained 8.2 g (0.018 mol yield 67%) of -4-methylmaleimide.

<Synthesis of specific polyamic acid and imidized polymer thereof>
Synthesis Examples P-1 to P-8
To the N-methylpyrrolidone, a diamine and tetracarboxylic dianhydride having the composition shown in Table 1 are added in this order to obtain a solution having a monomer concentration of 20% by weight, and reacted at 60 ° C. for 4 hours to give a polyamic acid (A-1). A solution containing ~ (A-8) was obtained. To each polyamic acid solution obtained, 3.0 times mole of pyridine and 3.0 times mole of acetic anhydride were added to the total amount of amic acid units in the solution, respectively, and then heated to 110 ° C. for 4 hours. A dehydration ring closure reaction was performed. The resulting solution was reprecipitated with diethyl ether, collected, and dried under reduced pressure to obtain imidized polymers (B-1) to (B-8). Table 1 shows the imidization ratio of these imidized polymers.
Synthesis Examples P-9 and P-10
Polyamic acids (A-9) and (A-10) were obtained in the same manner as in Synthesis Examples P-1 to P-8, except that diamines and tetracarboxylic dianhydrides described in Table 1 were used. . In Synthesis Examples P-9 and P-10, the polyamic acid was not subjected to dehydration ring closure reaction.

In Table 1, for diamine and tetracarboxylic dianhydride, the numbers in parentheses indicate the content ratio (molar ratio), and the meanings of the abbreviations in the table are as follows.
<Diamine>
Specific diamine A: 1- (3,5-diaminophenyl) -3-octadecyl succinimide Specific diamine B: 1- (3,5-diaminophenyl) -3-dodecyl succinimide Specific diamine C: 1- (3,5-diamino Phenyl) -3-heptadecyl-4-methylmaleimide Specific diamine D: 1- (3,5-diaminophenyl) -3-hexadecanoxymethyl-4-methylmaleimide Diamine 1: 4,4′-diaminodiphenylmethane <tetra Carboxylic dianhydride>
T-1: 2,3,5-tricarboxycyclopentyl acetic acid dianhydride T-2: 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid Acid anhydride T-3: Pyromellitic dianhydride T-4: 1,2,3,4-cyclobutanetetracarboxylic dianhydride

Example 1
The imidized polymer B-1 obtained in Synthesis Example P-1 and the polyamic acid A-9 (weight ratio 50:50) obtained in Synthesis Example P-9 and the total amount of the polymer as an organosilicon compound were 100 parts by weight. In contrast, 0.005 parts by weight of Shin-Etsu Silicone KF-6011 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd., PEG-11 methyl ether dimethicone) was mixed with a γ-butyrolactone / N-methyl-2-pyrrolidone / butyl cellosolve mixed solution ( Two solutions having a solid content concentration of 3.5% by weight and 5% by weight were prepared by dissolving at a weight ratio of 40:30:30). Each of these solutions was filtered using a filter having a pore size of 0.2 μm to prepare liquid crystal aligning agents at two concentrations. Among these, the viscosity of the liquid crystal aligning agent with a solid content concentration of 3.5% by weight is shown in Table 2.
Using these liquid crystal aligning agents, printability, voltage holding ratio, and image sticking were evaluated according to the method described above. The results are shown in Table 5.
Examples 2-36
The liquid crystal aligning agents 2 to 36 were prepared in the same manner as in Example 1 except that the types and amounts of the polymer and the organosilicon compound were as shown in Table 2. Prepared at various concentrations. Table 2 shows the viscosity of the liquid crystal aligning agent having a solid content concentration of 3.5% by weight.
In addition, Table 5 shows the results of evaluations performed using these liquid crystal aligning agents according to the method described above.

In Table 2, the abbreviations of organosilicon compounds have the following meanings, respectively.
KF-6011: trade name “Shin-Etsu Silicone KF-6011”, manufactured by Shin-Etsu Chemical Co., Ltd., PEG-11 methyl ether dimethicone KF-6012: trade name “Shin-Etsu Silicone KF-6012”, manufactured by Shin-Etsu Chemical Co., Ltd., PEG / PPG-20 / 22 butyl ether dimethicone SH3773M: trade name, manufactured by Toray Dow Corning Silicone Co., Ltd., polyoxyethylene methylpolysiloxane copolymer SH3749: trade name, manufactured by Toray Dow Corning Silicone Co., Ltd. , Poly (oxyethylene / oxypropylene) methylpolysiloxane copolymer

Example 37
The imidized polymer B-1 obtained in Synthesis Example P-1 and the polyamic acid A-9 (weight ratio 50:50) obtained in Synthesis Example P-9 and the total amount of the polymer as an organosilicon compound were 100 parts by weight. On the other hand, 0.005 parts by weight of Shin-Etsu Silicone KF-6011 and 20 parts by weight of polyethylene glycol diglycidyl ether (molecular weight: about 400) with respect to 100 parts by weight of the total amount of the polymer as an epoxy compound were added to γ-butyrolactone / It was dissolved in a mixed solution of N-methyl-2-pyrrolidone / butyl cellosolve (weight ratio 40:30:30) to prepare two types of solutions having a solid content concentration of 3.5% by weight and 5% by weight. Each of these solutions was filtered using a filter having a pore size of 0.2 μm, and liquid crystal aligning agents were prepared at two concentrations. Among these, the viscosity of the liquid crystal aligning agent with a solid content concentration of 3.5% by weight is shown in Table 3.
In addition, Table 5 shows the results of evaluations performed using these liquid crystal aligning agents according to the above-described method.
Examples 38-42
Each liquid crystal aligning agent was prepared at two different concentrations in the same manner as in Example 37 except that the types of the organosilicon compound and the epoxy compound used were as shown in Table 3. Table 3 shows the viscosity of the liquid crystal aligning agent having a solid content concentration of 3.5% by weight.
In addition, Table 5 shows the results of evaluations performed using these liquid crystal aligning agents according to the method described above.

In Table 3, the meanings of the abbreviations for the organosilicon compounds are the same as those in Table 2. The meaning of the abbreviation of the epoxy compound is as follows.
Epoxy A: Polyethylene glycol diglycidyl ether (molecular weight about 400)
Epoxy B: 1,6-hexanediol diglycidyl ether Epoxy C: N, N, N ′, N′-tetraglycidyl-2,2′-dimethyl-4,4′-diaminobiphenyl Epoxy D: N, N, N ', N'-tetraglycidyl-4,4'-diaminodiphenylmethane epoxy E: 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane epoxy F: N, N, N', N'-tetraglycidyl- m-xylenediamine

Comparative Examples 1-8
Each liquid crystal aligning agent was prepared at two different concentrations in the same manner as in Examples 1, 5, 9, 13, 17, 21, 25, and 29, except that no organosilicon compound was used. Among these, the viscosity of the liquid crystal aligning agent with a solid content concentration of 3.5% by weight is shown in Table 4.
Table 5 shows the results of the evaluation performed according to the above-described method using these liquid crystal aligning agents.

It is a schematic diagram which shows the pattern of the ITO electrode of the liquid crystal display element produced for evaluation of image sticking in an Example and a comparative example.

Claims (3)

The following formulas (1) and (2)

A tetracarboxylic dianhydride containing at least one selected from the group consisting of compounds represented by each of the following formulas (3) to (6):

Wherein R ^{1 to} R ⁴ are each independently a linear, branched or cyclic alkyl group having 1 to 40 carbon atoms, or a linear, branched or cyclic alkenyl group having 4 to 40 carbon atoms. And ¹ to 15 hydrogen atoms of R ^{1 to} R ⁴ may be substituted with fluorine atoms, and A ¹ and A ² are each independently a hydrogen atom or a methyl group.)
A polyamic acid and / or imidized polymer thereof obtained by a reaction with a diamine containing at least one selected from the compounds represented by:
Following formula (7)

(Where X ¹ represents the following formula (7-1) or (7-2)

(Here, R ⁵ is each independently a methylene group or polymethylene group, R ⁶ is an alkyl group, and a and b are each independently an integer of 1 to 20.)
And m and n are each independently an integer of 1 to 20. )
The liquid crystal aligning agent characterized by containing the compound represented by these, and a solvent.   Furthermore, the liquid crystal aligning agent of Claim 1 containing the compound which has a 2 or more epoxy group in a molecule | numerator.   A liquid crystal display element comprising a liquid crystal alignment film obtained from the liquid crystal aligning agent according to claim 1.

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