KR101310543B1 - Liquid Crystal Aligning Agent and Liquid Crystal Display Device - Google Patents

Abstract

The present invention provides liquid crystal wettability while providing a desired liquid crystal pretilt angle of 1 to 90 ° containing at least one of a polyamic acid which is a reaction product of diamine and tetracarboxylic dianhydride and an imidized polymer which is a dehydration ring closure product thereof. This excellent liquid crystal aligning agent is provided. Moreover, the liquid crystal display element which has a liquid crystal aligning film manufactured using the said liquid crystal aligning agent is provided.

Liquid crystal aligning agent, liquid crystal display element, polyamic acid, imidation polymer, diamine

Description

Liquid crystal aligning agent and liquid crystal display device {Liquid Crystal Aligning Agent and Liquid Crystal Display Device}

[Document 1] Japanese Unexamined Patent Publication No. 5-323327

[Document 2] Japanese Unexamined Patent Publication No. 2003-279996

[Document 3] Japanese Unexamined Patent Publication No. 2004-272112

[Patent 4] Japanese Unexamined Patent Publication No. 6-136122

[Document 5] Japanese Patent No. 2893671

[Document 6] Japanese Unexamined Patent Publication No. 2004-331937

[Document 7] Japanese Unexamined Patent Publication No. 2004-262921

The present invention relates to a novel liquid crystal aligning agent and a liquid crystal display element. More specifically, a liquid crystal comprising a novel liquid crystal aligning agent and a beautiful image having a novel pretilt angle expression component and providing a desired pretilt angle of 1 to 90 °, in which defects due to liquid crystal injection do not occur. It relates to a display element.

Liquid crystal display devices, which are represented by liquid crystal displays in terms of space saving and low power consumption, have been produced for the first time since liquid crystal calculators have been mass-produced, such as clocks, portable games, word processors, laptop computers, car navigation, camcorders, PDAs, and digital cameras. Applications in various fields such as mobile phones, various monitors, and liquid crystal televisions have been advanced, and active development has continued. Until now, TN (Twisted Nematic) or STN (Super Twisted Nematic) methods for driving liquid crystal molecules from parallel to vertical directions with respect to the substrate surface by voltage application using liquid crystals having positive dielectric anisotropy have been widely used. come. In addition, in recent years, in order to further improve the display quality of a liquid crystal display, an optical compensation vent (OCB) type liquid crystal display element having a small viewing angle dependency and excellent high-speed response required for moving picture display or a liquid crystal having a dielectric anisotropy is negative. In the Vertical Alignment (VA) method, liquid crystal molecules are arranged in parallel from perpendicular to the substrate surface. In the VA method, when the voltage is not applied, black display is performed, and thus the light transmittance can be easily reduced as compared with the TN method or the STN method, and it is possible to obtain a high contrast contrast without increasing the brightness of the backlight. Since the processing is also considered unnecessary, the use of the display for high display quality (especially a cellular phone or a liquid crystal television, etc.) is being advanced. In addition, a vertically oriented liquid crystal display device called MVA (Multi domain Vertical Alignment) method or PVA (Patterned Vertical Alignment) method with improved high viewing angle characteristics has been proposed, and VA method has further expanded its use. .

In the liquid crystal display device, the alignment of the liquid crystal is usually controlled by a liquid crystal alignment film formed by a liquid crystal aligning agent containing a polymer such as polyamic acid or polyimide. As described in Japanese Patent Application Laid-Open No. 5-323327, in the case of TN type and STN type liquid crystal display elements, the liquid crystal alignment film has a high freeness of liquid crystal in terms of preventing display unevenness caused by reverse tilt. It is desired to express the tilt angle. In addition, as described in Japanese Patent Laid-Open No. 2003-279996, in the case of the OCB type liquid crystal display device, the liquid crystal has a high level of liquid crystal in terms of preventing a decrease in brightness of the screen due to a reverse transition from the vent-type orientation to the spray orientation. It is desired to express the pretilt angle. On the other hand, in the case of the 0CB type liquid crystal display element described in Japanese Patent Laid-Open No. 2004-272112, the TN type is similar to the alignment film SE7492 manufactured by Nissan Chemical Industries, Ltd., which is usually used as an alignment film for TN type liquid crystal display elements. The liquid crystal aligning film used for a liquid crystal display element can also be used as an oriented film for OCB type liquid crystal display elements.

In the material design of a liquid crystal aligning film, in order to express the high pretilt angle of a liquid crystal, the chemical structure of the component (henceforth a pretilt angle expression component) which has a bulky hydrocarbon substituent in a side chain is selected suitably in a polymer, and Introduction techniques have been used. For example, the vertically oriented liquid crystal alignment film used in the VA method is disclosed in Japanese Patent Laid-Open No. 6-136122, Japanese Patent for aligning liquid crystal molecules perpendicularly to a substrate (to provide a 90 degree pretilt angle). As disclosed in Japanese Patent No. 2893671, Japanese Patent Laid-Open No. 2004-331937, and Japanese Patent Laid-Open No. 2004-262921, a pretilt angle expression component including a bulky hydrocarbon substituent is introduced into the polymer. However, these bulky hydrocarbon substituents provide a stable high frit angle, while lowering affinity with the liquid crystal, thereby degrading the wet expandability of the liquid crystal on the alignment film. Specifically, when the liquid crystal injection is carried out by the vacuum injection method, since the injection speed of the liquid crystal is remarkably lowered, the productivity of the cell manufacturing is very poor, and when the liquid crystal injection is carried out by the ODF method, the liquid crystal dropping portion or the fusion unit between the liquid crystals is used. There existed a problem that orientation nonuniformity generate | occur | produced etc. and the display defect of a liquid crystal display element arises. Therefore, in order to improve the said problem, development of the liquid crystal aligning agent excellent in the wettability by a liquid crystal is expressly required, expressing the high pretilt angle of a liquid crystal.

This invention is made | formed based on the above circumstances, The objective of this invention was made using the liquid crystal aligning agent excellent in liquid crystal wettability, and the said liquid crystal aligning agent, providing the desired liquid crystal pretilt angle of 1-90 degrees. It is providing the liquid crystal display element which has a liquid crystal aligning film.

According to the present invention, the above object of the present invention is, firstly, the first diamine represented by the following formula (1) and the second diamine represented by the following formula (2) and tetracarboxylic acid represented by the following formula (3) It is achieved by the liquid crystal aligning agent containing at least any one of the polyamic acid obtained by making a dianhydride react, and the imidation polymer produced | generated by dehydrating and ring-closing the said polyamic acid.

(Wherein R ₁ and R ₂ are each independently a hydrogen atom; a halogen atom; a substituted or unsubstituted carbon atom having 1 to 30 carbon atoms which may have a linking group including an oxygen atom, a nitrogen atom, a sulfur atom or a silicon atom); Hydrocarbon group or polar group, provided that 5 R ₂ may be the same or different, and at least one of R ₁ and 5 R ₂ is a substituent including a fluorine atom)

H ₂ NR ₃ -NH ₂

(Wherein R ₃ is a divalent organic group)

(Wherein R ₄ is a tetravalent organic group)

Moreover, according to this invention, the said objective of this invention is achieved by the liquid crystal display element provided with the liquid crystal aligning film formed from the said liquid crystal aligning agent.

Hereinafter, the present invention will be described in detail.

[Polyamic acid and imidized polymer]

The polyamic acid used in the present invention is obtained by carrying out the polyaddition reaction of the diamine represented by the formula (1) and the formula (2) and the tetracarboxylic dianhydride represented by the formula (3). In addition, the imidation polymer used by this invention is obtained by dehydrating and ring-closing the said polyamic acid.

[Diamine]

The liquid crystal aligning agent of this invention expresses the desired pretilt angle by copolymerizing the diamine represented by the said Formula (1) as a diamine, and also expresses the performance excellent in the wettability of a liquid crystal.

When using the liquid crystal aligning agent of this invention in TN mode, STN mode, and OCB mode in this invention, the ratio of the 1st diamine compound represented by the said Formula (1) is represented by the diamine represented by the said Formula (1), and the said Formula (2). The total amount of diamine is preferably 1 to 10 mol%, more preferably 1 to 8 mol%, particularly preferably 1 to 5 mol%. If the ratio of the first diamine compound represented by the formula (1) is less than 1 mol%, sufficient pretilt angle and liquid crystal wettability are not obtained. If the ratio is more than 10 mol%, the pretilt angle is used as the TN mode, STN mode, or OCB mode. Can be too high.

When using the liquid crystal aligning agent of this invention in VA mode in this invention, the ratio of the 1st diamine compound represented by the said General formula (1) becomes like this. Preferably it is 10-99 mol%, More preferably, it is 12-13 50 mol%, Especially preferably, it is 15-40 mol%. If the ratio of the first diamine compound represented by the general formula (1) is too small, sufficient vertical alignment is hardly obtained, and if too large, poor coating properties such as pinhole generation may occur when forming the alignment layer.

A halogen atom represented by R ₁ and R ₂ in Formula 1; A substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms which may have a linking group containing an oxygen atom, a nitrogen atom, a sulfur atom or a silicon atom; And a polar group.

As a halogen atom, a fluorine atom, a chlorine atom, and a bromine atom are mentioned, for example.

As a hydrocarbon group of 1-30 carbon atoms, For example, Alkyl groups, such as a methyl group, an ethyl group, and a propyl group; A cycloalkyl group such as a cyclopentyl group and a cyclohexyl group; Alkenyl groups such as a vinyl group and an allyl group; An alkylidene group such as an ethylidene group and a propylidene group; And aromatic groups such as a phenyl group, a naphthyl group, an anthracenyl group, a biphenyl group, and a fluorenyl group. Among these groups, hydrogen atoms bonded to carbon atoms may be substituted with halogen atoms such as fluorine, chlorine, bromine and cyano groups.

In addition, the substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms may be directly bonded to the benzene ring structure represented by Formula 1 (for R ₂ ) and carbon atom (for R ₁ ), or a linking group. It can also be combined through. Examples of the linking group include an alkylene group represented by, for example, a divalent hydrocarbon group having 1 to 10 carbon atoms, for example,-(CH ₂ ) _m- (wherein m is an integer of 1 to 10); A linking group containing an oxygen atom, a nitrogen atom, a sulfur atom or a silicon atom (for example, a carbonyl group (-CO-), a carbonyloxy group (-CO0-), a sulfonyl group (-SO _2- ), a sulfonyloxy group ( -SO ₂ -O-), ether bond (-O-), thioether bond (-S-), imino group (-NH-), amide bond (-NHCO-), siloxane bond (-Si (R) ₂ O-) (wherein R is an alkyl group such as a methyl group or an ethyl group); or two or more thereof are combined and connected.

As the polar group, for example, a hydroxyl group, an alkoxy group having 1 to 10 carbon atoms, an alkylcarbonyloxy group, an arylcarbonyloxy group, an alkoxycarbonyl group, an aryloxycarbonyl group, a cyano group, a nitro group, an amide group, an imino group (= there may be mentioned NH), tri organo-siloxy group, tri-organo-silyl group, an amino group, an acyl group, an alkoxysilyl group, a sulfonic acid group (-SO ₃ H), pinot alcohol group (-SO ₂ H), and a carboxyl group, etc. .

More specifically, as said alkoxy group, a methoxy group, an ethoxy group, etc. are mentioned, for example; As an alkyl carbonyloxy group, an acetoxy group, a propionyloxy group, etc. are mentioned, for example; As an arylcarbonyloxy group, a benzoyloxy group etc. are mentioned, for example; As an alkoxycarbonyl group, a methoxycarbonyl group, an ethoxycarbonyl group, etc. are mentioned, for example; Examples of the aryloxycarbonyl group include phenoxycarbonyl group, naphthyloxycarbonyl group, fluorenyloxycarbonyl group, biphenylyloxycarbonyl group, and the like; Examples of the triorganosiloxy group include trimethylsiloxy group, triethylsiloxy group, and the like; Examples of the triorganosilyl group include trimethylsilyl group and triethylsilyl group; As an amino group, a secondary amino group, a tertiary amino group, etc. are mentioned, for example, As an alkoxy silyl group, a trimethoxy silyl group, a triethoxy silyl group, etc. are mentioned, for example.

In Formula 1, at least one of R ₁ and five R ₂ is a substituent containing a fluorine atom, and preferably at least one of the substituents represented by five R ₂ is a substituent including a fluorine atom. As such a group containing a fluorine atom in R ₁ and R ₂ , an alkyl fluoride group is preferable, and in that case, the carbon number of the alkyl fluoride group is preferably 1 to 40, more preferably 2 to 25, and particularly preferably 5 to 15. When the number of carbon atoms in the group (fluorinated alkyl group) containing fluorine atoms in R ₁ and R ₂ is small, sufficient pretilt angle cannot be expressed, and when the number of carbon atoms is 40 or more, pinholes are generated during formation of the alignment film. Poor applicability of may occur. In addition, although the substituent (alkyl fluoride group) containing the fluorine atom in R <_1> and R <_2> may be either linear, branched, or cyclic structure, it is preferable that it is linear in the point which is excellent in liquid crystal pretilt angle expressability. Do.

Specific examples of the diamine represented by the general formula (1) include the compounds described below:

4,4'-diamino-4 ''-fluorotriphenylmethane represented by the following formula (1-1)

(1-1)

(1-1)

4,4'-diamino-4 ''-trifluoromethyltriphenylmethane represented by the following formula (1-2)

(1-2)

(1-2)

4,4'-diamino-4 ''-trifluoromethoxytriphenylmethane represented by the following formula (1-3)

(1-3)

(1-3)

4,4'-diamino-3 '', 5 ''-bistrifluoromethyltriphenylmethane represented by the following formula (1-4)

(1-4)

(1-4)

4,4'-diamino-4 ''-pentafluoroethyltriphenylmethane represented by the following formula (1-5)

(1-5)

(1-5)

4,4'-diamino-4 ''-heptafluoropropyltriphenylmethane represented by the following formula (1-6)

(1-6)

(1-6)

4,4'-diamino-4 ''-nonafluorobutyltriphenylmethane represented by the following formula (1-7)

(1-7)

(1-7)

4,4'-diamino-4 ''-undecafluoropentyltriphenylmethane represented by the following formula (1-8)

(1-8)

(1-8)

4,4'-diamino-4 ''-tridecafluorohexyltriphenylmethane represented by the following formula (1-9)

(1-9)

(1-9)

4,4'-diamino-4 ''-pentadecafluoroheptyltriphenylmethane represented by the following formula (1-10)

(1-10)

(1-10)

4,4'-diamino-4 ''-heptadecafluorooctyltriphenylmethane represented by the following formula (1-11)

(1-11)

(1-11)

4,4'-diamino-4 ''-nonadecafluorononyltriphenylmethane represented by the following formula (1-12)

(1-12)

(1-12)

4,4'-diamino-4 ''-henicosafluorodecyltriphenylmethane represented by the following formula (1-13)

(1-13)

(1-13)

The first amines represented by Formula 1 may be used alone or in combination of two or more thereof.

Especially, as a 1st diamine, 4,4'- diamino-4 "-undechafluoropentyl triphenylmethane represented by the said General formula (1-8), and 4 represented by the said General formula (1-9) , 4'-diamino-4 ''-tridecafluorohexyltriphenylmethane, 4,4'-diamino-4 ''-pentadecafluoroheptyltriphenyl represented by the formula (1-10) Methane, 4,4'-diamino-4 ''-heptadecafluorooctyltriphenylmethane represented by the formula (1-11), 4,4'-dia represented by the formula (1-12) Mino-4 ''-nonadecafluorononyltriphenylmethane, 4,4'-diamino-4 ''-henicosafluorodecyltriphenylmethane represented by the general formula (1-13) is preferable, and in particular, 4,4'-diamino-4 ''-heptadecafluorooctyltriphenylmethane represented by the formula (1-11) forms an alignment agent excellent in liquid crystal pretilt angle expression and applicability in forming an alignment film It is preferable at the point.

As a 2nd diamine compound represented by the said Formula (2), it is p-phenylenediamine, m-phenylenediamine, 4,4'- diamino diphenylmethane, 4,4'- diamino diphenylethane, 4, for example. , 4'-diaminodiphenylsulfide, 4,4'-diaminodiphenylsulfone, 2,2'-dimethyl-4,4'-diaminobiphenyl, 4,4'-diaminobenzanilide, 4 , 4'-diaminodiphenylether, 1,5-diaminonaphthalene, 3,3'-dimethyl-4,4'-diaminobiphenyl, 5-amino-1- (4'-aminophenyl) -1 , 3,3-trimethylindan, 6-amino-1- (4'-aminophenyl) -1,3,3-trimethylindan, 3,4'-diaminodiphenylether, 3,3'-dia Minobenzophenone, 3,4'-diaminobenzophenone, 4,4'-diaminobenzophenone, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2- Bis (4-aminophenyl) hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] sulfone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-a Nophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 9,9-bis (4-aminophenyl) -10-hydroanthracene, 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 Aromatic diamines such as c]]-octafluorobiphenyl, 1,3-bis (4-aminophenoxy) -2,2-dimethylpropane, and 4,4'-bis (4-aminophenoxy) biphenyl;

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, 4,6-dia Mino-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-phenylphenanthtridine, 1,4-diaminopiperazine, Molecules, such as 3,6-diaminoacridine, bis (4-aminophenyl) phenylamine and compounds represented by the following formulas (4) and (5) The two primary amino groups and a diamine having a nitrogen atom other than the primary amino groups

(Wherein R ₅ represents a monovalent organic group having a ring structure including a nitrogen atom selected from pyridine, pyrimidine, triazine, piperidine and piperazine, and X represents a divalent organic group)

(Wherein R ₆ represents a divalent organic group having a ring structure containing a nitrogen atom selected from pyridine, pyrimidine, triazine, piperidine and piperazine;

Mono substituted phenylenediamine represented by the following formula (6)

(Wherein R ₇ represents a divalent organic group selected from -O-, -COO-, -OCO-, -NHCO-, -CONH- and -CO-, R ₈ represents a steroid skeleton, a trifluoromethyl group, A monovalent organic group or an alkyl group having 6 to 30 carbon atoms having at least one group selected from trifluoromethoxy group and fluoro group;

1,3-bis (aminomethyl) cyclohexane, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, 4,4-diaminohepta Methylenediamine, 1,4-diaminocyclohexane, isophoronediamine, tetrahydrodicyclopentadienylenediamine, tricyclo [6.2.1.0 ^2,7 ] -undecylenedimethyldiamine, 4,4'-methylenebis (cyclo Aliphatic and alicyclic diamines such as hexylamine);

Diaminoorganosiloxane represented by the following formula (7)

(In formula, R <_9> represents a C1-C12 hydrocarbon group, two or more R <_9> may be same or different, p is an integer of 1-3, q is an integer of 1-20. have. These second amines are used alone or in combination of two or more thereof.

Among them, p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfide, 1,5-diaminonaphthalene, 2,7-diaminofluorene, 4 , 4'-diaminodiphenylether, 9,9-bis (4-aminophenyl) fluorene, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4 -(4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 1,4-bis (4-aminophenoxy) benzene, 4,4'- Bis (4-aminophenoxy) biphenyl, 4,4'-diamino-2,2'-bis (trifluoromethyl) biphenyl, 4,4'-diamino-2,2'-dimethylbiphenyl , 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminoacridine, among the compounds represented by the formula (4) Among the compounds represented by the above, the compound represented by the formula (5-1) of the compound represented by the formula (5), and the compound represented by the formula (6) Compounds represented by the formulas (6-1), (6-2), (6-3) and (6-4), respectively, 1,3-bis (aminomethyl) cyclohexane, 1,4-cyclohexanediamine , 4,4'-methylenebis (cyclohexylamine), among the compounds represented by the formula (7), 3,3 '-(tetramethyldisiloxane-1,3-diyl) represented by the following formula (7-1) Bis (propylamine) is preferred:

Especially preferred are p-phenylenediamine, 4,4'-diaminodiphenylmethane, 2,2'-dimethyl-4,4'-diaminobiphenyl, 1,3'-bis (4-aminophenoxy ) -2,2-dimethylpropane, 2,7-diaminofluorene, 4,4'-diaminodiphenylether, 3,3 '-(tetramethyldisiloxane-1,3-diyl) bis (propylamine ), 1,3-bis (aminomethyl) cyclohexane, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4'-diamino-2,2'-bis (trifluoromethyl) Biphenyl is mentioned.

[Tetracarboxylic acid dianhydride]

Examples of the tetracarboxylic dianhydride include butane tetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2,3,4- Cyclobutane tetracarboxylic acid dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutane tetracarboxylic acid dianhydride, 1,3-dichloro-1,2,3,4-cyclobutanetetracar Tetramethyl-1,2,3,4-cyclobutane tetracarboxylic acid dianhydride, 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride, 1,2,3,4- 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride, 3,3 ', 4,4'-dicyclohexyltetracarboxylic acid dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride , 3,5,6-tricarboxy norbornane-2-acetic acid dianhydride, 2,3,4,5-tetrahydrofuran tetracarboxylic acid dianhydride, 1,3,3a, 4,5,9b-hexa (Tetrahydro-2,5-dioxo-3-furanyl) -naphtho [l, 2-c] 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, 1,3,3a, 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, 5- (2,5-di Oxotet lahydrofural) -3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, bicyclo [2,2,2]- Tetra-7-en-2,3,5,6-tetracarboxylic dianhydride, 3-oxabicyclo [3.2.1] octane-2,4-dione-6-spiro-3 '-(tetrahydrofuran -2 ', 5'-dione), aliphatic and alicyclic tetracarboxylic dianhydrides such as compounds represented by the following formulas (8) and (9)

(Wherein R ₁₀ and R ₁₂ represent a divalent organic group having an aromatic ring, R ₁₁ and R ₁₃ represent a hydrogen atom or an alkyl group, and a plurality of R ₁₁ and R ₁₃ may be the same or different, respectively) ;

Pyromellitic dianhydride, 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 3,3', 4,4'-biphenylsulfontetracarboxylic dianhydride, 1,4,5 , 8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3 ', 4,4'-biphenylethertetracarboxylic dianhydride, 3,3 ', 4,4'-dimethyldiphenylsilanetetracarboxylic dianhydride, 3,3', 4,4'-tetraphenylsilanetetracarboxylic dianhydride, 1,2,3,4-furantetracarboxylic Acid dianhydrides, 4,4'-bis (3,4-dicarboxyphenoxy) diphenylsulfide dianhydrides, 4,4'-bis (3,4-dicarboxyphenoxy) diphenylsulfone dianhydrides, 4 , 4'-bis (3,4-dicarboxyphenoxy) diphenylpropane dianhydride, 3,3 ', 4,4'-perfluoroisopropylidenediphthalic dianhydride, 3,3', 4,4 '-Biphenyltetracarboxylic dianhydride, bis (phthalic acid) phenylphosphineoxide 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 (anhydrotrimelitate), propylene glycol -bis (anhydrotrimelitate), 1,4-butanediol-bis (anhydrotrimelitate), 1,6-hexanediol-bis (an Hydrotrimellitate), 1,8-octanediol-bis (anhydrotrimellitate), 2,2-bis (4-hydroxyphenyl) propane-bis (anhydrotrimelitate), the following formulas 10 to 13 Aromatic tetracarboxylic dianhydrides, such as a compound represented by these, are mentioned.

These may be used singly or in combination of two or more.

Among them, butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride , 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 5 -(2,5-dioxotetrahydrofural) -3-methyl-3-cyclohexene-1,2-dicarboxylic 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), pyromellitic dianhydride, 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 3,3', 4,4 '-Biphenylsulfontetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, among the compounds represented by the formula (8) to the formulas (8-1) to (8-3) The compound represented by following General formula (9-1) among the compound shown and the compound represented by the said Formula (9-1) is preferable at the point which can express favorable liquid-crystal orientation. As particularly preferred, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,4, 5-cyclohexanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic 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, 3-oxabicyclo [3.2.1] octane-2,4-dione-6 -Spiro-3 '-(tetrahydrofuran-2', 5'-dione), pyromellitic dianhydride, 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride and the following formula (8- The compound represented by 1) is mentioned:

These tetracarboxylic dianhydrides are used individually by 1 type or in combination of 2 or more types.

<Synthesis of polyamic acid>

The use ratio of the tetracarboxylic dianhydride and the diamine compound provided in the synthesis reaction of the polyamic acid of the present invention is such that the acid anhydride group of the tetracarboxylic dianhydride is 0.2 to 2 equivalents to 1 equivalent of the amino group contained in the diamine compound. This is preferable and it is the ratio which becomes like this. More preferably, it is 0.3-1.2 equivalent.

The synthesis reaction of the polyamic acid is carried out in an organic solvent at a temperature of preferably -20 to 150 ° C, more preferably 0 to 100 ° C. The organic solvent is not particularly limited as long as it can dissolve the polyamic acid synthesized. For example, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl Aprotic polar solvents such as sulfoxide, γ-butyrolactone, tetramethylurea and hexamethylphosphortriamide; Phenol solvents, such as m-cresol, xylenol, a phenol, and a halogenated phenol, can be illustrated. Moreover, it is preferable that the usage-amount (a) of an organic solvent is an amount which will be 0.1-30 weight% with respect to the total amount (a + b) of the total amount (b) of tetracarboxylic dianhydride and a diamine compound.

<Poor solvent>

In the organic solvent, alcohol, ketone, ester, ether, halogenated hydrocarbon, hydrocarbons, and the like, which are poor solvents of polyamic acid, may be used in combination without causing precipitation of the resulting polyamic acid. As a specific example of such a poor solvent, for example, methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, diacetone alcohol, ethylene glycol monomethyl ether, Ethyl lactate, butyl lactate, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, methyl methoxy propionate, ethyl ethoxy propionate, propylene carbonate, oxalic acid Diethyl, diethyl malonate, diethyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol monobutyl 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, tetrahydrofuran, dichloromethane, 1,2-dichloroethane, 1,4 -Dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene, hexane, heptane, octane, benzene, toluene, xylene and the like. These poor solvents may be used alone or in combination of two or more.

In this way, a reaction solution obtained by dissolving polyamic acid is obtained. Then, the reaction solution is poured into a large amount of poor solvent to obtain a precipitate, and then the precipitate is dried under reduced pressure to obtain a polyamic acid. Subsequently, the polyamic acid can be purified by dissolving the polyamic acid again in an organic solvent and then precipitating with a poor solvent once or several times.

<Imidized Polymer>

The imidized polymer of this invention can be synthesize | combined by dehydrating and ring-closing the said polyamic acid. The imidation polymer here includes the partial imide polymer which partially imidated the said polyamic acid, and the polymer which imidated 100%, and these are collectively described as "imidization polymer."

The imidation ratio in the imidation polymer used for this invention becomes like this. Preferably it is 10 to 100%, More preferably, it is 30 to 98%, Especially preferably, it is 40 to 97%. Here, the "imidization rate" is defined as the ratio of the number of repeating units formed by forming an imide ring to the total number of repeating units in the polymer in%. In this case, a part of the imide ring may be an isomeric ring.

As a method of synthesizing the imidized polymer, (i) a method of dehydrating and ring-closing by heating the polyamic acid, and (ii) dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydrating ring-closure catalyst to the solution, and The method of dehydrating the ring-closure by heating according to the present invention, and (iii) the method of mixing tetracarboxylic dianhydride, a diamine compound, and a diisocyanate compound, and condensing and synthesizing by heating as needed, the said reaction conditions suitably It is adjusted and the polymer which has a desired imidation ratio is obtained.

In the method of said (i), reaction temperature becomes like this. Preferably it is 300 degrees C or less, More preferably, it is 100-250 degreeC. When reaction temperature exceeds 300 degreeC, the molecular weight of the imidation polymer obtained may fall.

On the other hand, as a dehydrating agent used by the method of said (ii), acid anhydrides, such as acetic anhydride, a propionic anhydride, and trifluoroacetic anhydride, can be used, for example. It is preferable that the usage-amount of a dehydrating agent shall be 0.2-20 mol with respect to 1 mol of repeating units of a polyamic acid. As the dehydration cyclization catalyst, for example, tertiary amines such as pyridine, collidine, lutidine and triethylamine can be used. However, the dehydrating agent and the dehydration ring-closing catalyst are not limited to these examples. In addition, it is preferable that the usage-amount of an imidation catalyst shall be 0.1-10 mol with respect to 1 mol of dehydrating agents to be used. On the other hand, as an organic solvent used for reaction of dehydration ring closure, the thing similar to the organic solvent illustrated as what is used for the synthesis | combination of a polyamic acid is mentioned. The reaction temperature of the dehydration ring closure is preferably 0 to 180 ° C, more preferably 60 to 150 ° C. Moreover, the imidation polymer can be refine | purified by performing the same operation as the purification method of a polyamic acid with respect to the reaction solution obtained in this way.

As a specific example of the diisocyanate compound used by reaction of said (iii), Aliphatic diisocyanate, such as hexamethylene diisocyanate; Cyclohexane-1,2-diisocyanate, 1-methylcyclohexane-2,4-diisocyanate, 1,2-dimethylcyclohexane-ω, ω'-diisocyanate, 1,4-dimethylcyclohexane-ω, ω Alicyclic diisocyanates such as' -isocyanate, isophorone diisocyanate, 1,3,5-trimethyl-2-propylcyclohexane-1ω, 2ω'-diisocyanate, dicyclohexylmethane-4,4'-diisocyanate ; Diphenylmethane-4,4'-diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 1-methyl-2,6-phenylene diisocyanate, represented by the following formulas 14 to 17 Aromatic diisocyanate, such as diisocyanate which is mentioned, is mentioned.

Among them, dicyclohexylmethane-4,4'-diisocyanate, diphenylmethane-4,4'-diisocyanate, 1-methyl-2,4-phenylene diisocyanate, 1-methyl-2,6-phenyl Lene diisocyanate is mentioned as a preferable thing. These may be used alone or in combination of two or more. On the other hand, the catalyst of (iii) does not require a catalyst in particular, and reaction temperature becomes like this. Preferably it is 50-200 degreeC, More preferably, it is 100-160 degreeC.

&Lt; End Modified Polymer &

The polyamic acid and the imidation polymer which comprise the liquid crystal aligning agent of this invention may be a terminal modified type with a molecular weight adjusted. By using this polymer of terminal modification, the effect of this invention can be improved, and the coating characteristic of a liquid crystal aligning agent can be improved. Such a terminal modification type can be synthesized by adding an acid anhydride, a monoamine compound, a monoisocyanate compound or the like to the reaction system in the synthesis of the polyamic acid. Here, examples of the acid anhydride include maleic anhydride, phthalic anhydride, itaconic anhydride, n-decylsuccinic anhydride, n-dodecylsuccinic anhydride, n-tetradecylsuccinic anhydride, n-hexadecylsuccinic anhydride, and the like. have. As the monoamine compound, for example, aniline, cyclohexylamine, p-ethylaniline, 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, etc. are mentioned. Examples of the monoisocyanate compound include phenyl isocyanate and naphthyl isocyanate.

Logarithmic viscosity of the polymer

The value of the logarithmic viscosity (η _ln ) of the polyamic acid and imidized polymer obtained as mentioned above becomes like this. Preferably it is 0.05-10 dl / g, More preferably, it is 0.05-5 dl / g.

The value of the logarithmic viscosity (η _ln ) in the present invention uses N-methyl-2-pyrrolidone as a solvent, and the viscosity is measured at 30 ° C for a solution having a concentration of 0.5 g / 100 milliliter, Obtained by

<Liquid Crystal Aligner>

The polyamic acid and imidation polymer which comprise the liquid crystal aligning agent of this invention, Preferably, it melts and contains in an organic solvent, and is comprised. In order to improve the characteristics, such as voltage retention and baking resistance (residual DC), and coating-film property, the liquid crystal aligning agent of this invention does not contain the diamine structure represented by the said General formula (1) at the time of aligning agent adjustment, and / or Other imidized polymers can also be added. The other polyamic acid and / or other imidation polymer to be added may be one kind or plural kinds, depending on the purpose, and usually other polyamic acid is preferred, in particular 1,2,3,4-cyclobutanetetracarboxylic acid Dianhydrides, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 2,3,5-tri Carboxycyclopentylacetic 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, 3-oxabicyclo [3.2.1] octane-2,4-dione-6-spiro-3 '-(tetrahydrofuran-2', 5'-dione ), At least one acid dianhydride selected from pyromellitic dianhydride, p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfide, 1,5-diaminonaphthalene, 2,7-diaminofluorene, 4,4'-diaminodiphenylether, 9,9-bis (4-aminophenyl) fluorene, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4'-diamino-2,2'-bis (trifluoromethyl ) At least one diamine selected from biphenyl, 4,4'-diamino-2,2'-dimethylbiphenyl, 3,3- (tetramethyldisiloxane-1,3-diyl) bis (propylamine) Other polyamic acid obtained by making it react is preferable. Polyamic acid and / or imidization polymer containing a diamine structure represented by the formula (1) (these are referred to as polymer "X") and other polyamic acid and / or other imidizations not containing the diamine structure represented by the formula (1) The mixing ratio of the polymers (they are referred to as polymer "Y") is preferably in the range of X: Y = 10: 90 to 90:10 by weight ratio, more preferably X: Y = 15: 85 to 60:40 Especially preferably, it is the range which becomes X: Y = 20: 80-50: 50.

The temperature at which the liquid crystal aligning agent of the present invention is produced is preferably 0 to 200 캜, more preferably 20 to 60 캜.

As an organic solvent which comprises the liquid crystal aligning agent of this invention, the thing similar to the solvent illustrated as what is used for the synthesis reaction of polyamic acid is mentioned. Among them, solvents having a boiling point of 160 ° C. or higher are preferable in terms of printability, and for example, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, dimethyl sulfoxide, γ-butyrolactone, tetramethylurea, Hexamethylphosphortriamide, m-cresol, xylenol, phenol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, diacetone alcohol, butyl lactate, butyl acetate, ethyl ethoxy Propionate, propylene carbonate, diethyl oxalate, diethyl malonate, ethylene glycol monobutyl ether (butyl cellosolve), diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, di Ethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, 1,4-dichlorobutane, o-dichlorobenzene, and the like. Methyl-2-pyrrolidone, γ-butyrolactone, diacetone alcohol, ethylene glycol monobutyl ether (butyl cellosolve), propylene carbonate and diethylene glycol diethyl ether are particularly preferable.

The solid concentration in the liquid crystal aligning agent of the present invention is selected in consideration of viscosity, volatility, etc., but is preferably in the range of 1 to 10% by weight. Although the liquid crystal aligning agent is apply | coated to the surface of a board | substrate, and the coating film used as a liquid crystal aligning film is formed, when solid content concentration is less than 1 weight%, the film thickness of this coating film becomes too small and a favorable liquid crystal aligning film cannot be obtained, and solid content concentration is 10 weight% When exceeding, the film thickness of a coating film becomes too large and a favorable liquid crystal aligning film cannot be obtained, and also the viscosity of a liquid crystal aligning agent increases and application | coating characteristics fall.

The viscosity of the liquid crystal aligning agent of the present invention (viscosity measured at 25 ° C. using a rotary viscometer) needs to be appropriately adjusted according to the method of applying the aligning agent. The viscosity of a liquid crystal aligning agent is 3-100 mPa * s normally, Preferably it is 4-50 mPa * s, Especially preferably, it is the range which becomes 5-35 mPa * s.

In the aspect which improves the adhesiveness to the surface of a board | substrate, the liquid crystal aligning agent of this invention may contain a functional silane containing compound or an epoxy group containing compound. As such a functional silane containing compound, 3-aminopropyl trimethoxysilane, 3-aminopropyl triethoxysilane, 2-aminopropyl trimethoxysilane, 2-aminopropyl triethoxysilane, N- ( 2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltrier Methoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-tri Methoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecan, 10-triethoxysilyl-1,4,7-triazadecan, 9-trimethoxysilyl- 3,6-diazanyl acetate, 9-triethoxysilyl-3,6-diazanyl acetate, N-benzyl-3-aminopropyltrimethoxysilane, N- Jyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3-aminopropyltri Methoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, etc. are mentioned.

As the epoxy group-containing compound, 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-dibromoneopentyl glycol diglycidyl ether, 1,3, 5,6-tetraglycidyl-2,4-hexanediol, N, N, N ', N'-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidyl Aminomethyl) cyclohexane, N, N, N ', N'- tetraglycidyl-4,4'- diamino diphenylmethane, etc. are mentioned as a preferable thing. The blending ratio of these functional silane-containing compounds and epoxy group-containing compounds is preferably 60 to 100 parts by weight of the polyamic acid and / or the imidized polymer (when other polyamic acids and other imidized polymers are also used in combination), The weight part or less, More preferably, it is 50 weight part or less.

<Liquid crystal display element>

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

(1) The liquid crystal aligning agent of this invention is apply | coated to one surface of the board | substrate with which the patterned transparent conductive film is provided by methods, such as a roll coater method, a spinner method, the printing method, the inkjet method, and then, a coating surface is heated. This forms a coating film. Here, as a board | substrate, For example, glass, such as float glass and a soda glass; A transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, polycarbonate, and alicyclic polyolefin can be used. Examples of the transparent conductive film provided on one surface of the substrate include an NESA film (registered trademark of PPG Co., Ltd.) containing tin oxide (SnO ₂ ), an ITO film containing indium tin oxide (In ₂ O ₃ -SnO ₂ ), and the like. Can be used. For the patterning of these transparent conductive films, a method using a photo-etching method or a preliminary mask is used. As the reflective electrode, a metal such as Al or Ag, or an alloy containing these metals can be used, but the reflective electrode is not limited thereto as long as it has a sufficient reflectance. A functional silane-containing compound, a functional titanium-containing compound, or the like may be applied in advance to the surface of the substrate in order to further improve the adhesion between the substrate surface and the transparent conductive film or the reflective electrode and the coating film when the liquid crystal aligning agent is applied. have. After application of the liquid crystal aligning agent, preheating (prebaking) is usually performed for the purpose of preventing the sagging of the applied alignment agent. Prebaking temperature becomes like this. Preferably it is 30-300 degreeC, More preferably, it is 40-200 degreeC, Especially preferably, it is 50-150 degreeC. Thereafter, the solvent is completely removed and a firing (postbaking) step is performed for the purpose of thermally imidizing the polyamic acid with the polyimide. The firing (post-baking) temperature is preferably 80 to 300 占 폚, and more preferably 120 to 250 占 폚. In this way, the liquid crystal aligning agent of this invention containing a polyamic acid forms the coating film used as an oriented film by removing an organic solvent after application | coating, and it can further be made into the imidized coating film by advancing dehydration ring closure by further heating. The film thickness of the coating film formed becomes like this. Preferably it is 0.001-1 micrometer, More preferably, it is 0.005-0.5 micrometer.

(2) If necessary, a rubbing treatment is performed in which the formed coating film surface is rubbed in a predetermined direction with a roll wound with a cloth made of fibers such as nylon, rayon, or cotton. Accordingly, the alignment ability of the liquid crystal molecules is imparted to the coating film to form a liquid crystal alignment film. On the other hand, in addition to the method by a rubbing process, the method of irradiating polarized ultraviolet light to the coating film surface and controlling an orientation capability can also be applied. On the other hand, it is preferable to clean the formed liquid crystal alignment film with isopropyl alcohol and / or pure water in order to remove the fine powder (foreign matter) generated in rubbing treatment or the like and to make the surface of the coated film clean. Further, the liquid crystal alignment film formed by the liquid crystal aligning agent of the present invention partially irradiates ultraviolet rays as disclosed in, for example, Japanese Patent Application Laid-Open No. 6-222366 or Japanese Patent Application Laid-Open No. 6-281937. Thereby forming a resist film partially on the rubbed liquid crystal alignment film as disclosed in Japanese Patent Laid-Open No. Hei 5-107544, or in a direction different from the rubbing treatment previously performed. After performing a rubbing process, it is possible to improve the viewing characteristic of a liquid crystal display element by performing the process of removing the said resist film and changing the orientation capability of a liquid crystal aligning film.

(3) Two board | substrates with a liquid crystal aligning film were manufactured as mentioned above, and two board | substrates were opposingly arranged through a clearance gap (cell spacing) so that the rubbing direction in each liquid crystal aligning film may become orthogonal or antiparallel, The periphery of the substrate is bonded with a sealant, the liquid crystal is injected and filled into the cell surface partitioned by the substrate surface and the sealant, and the injection hole is sealed to form a liquid crystal cell. And a liquid crystal display element is obtained by arrange | positioning a polarizing plate in the outer surface of the liquid crystal cell, ie, the outer surface side of each board | substrate which comprises a liquid crystal cell.

As the sealant, for example, an epoxy resin containing aluminum oxide spheres as a curing agent and a spacer can be used.

Examples of the liquid crystal include a nematic liquid crystal and a smectic liquid crystal. Especially, a nematic type liquid crystal is preferable, for example, a Schiff base type liquid crystal, a subfamily clock liquid crystal, a biphenyl type liquid crystal, a phenyl cyclohexane type liquid crystal, an ester type liquid crystal, a terphenyl type liquid crystal, a biphenyl cyclohexane type liquid crystal, a pyrimi Din type liquid crystal, a dioxane type liquid crystal, a bicyclo octane type liquid crystal, a cuban type liquid crystal, etc. can be used. In addition, these liquid crystals are sold, for example, as cholesteric liquid crystals such as cholesteryl chloride, cholesteryl nonate, and cholesteryl carbonate, or trade names "C-15" and "CB-15" (manufactured by Merck). It is also possible to add and use a chiral agent. In addition, ferroelectric liquid crystals such as p-decyloxybenzylidene-p-amino-2-methylbutyl cinnamate can also be used.

Moreover, as a polarizing plate bonded to the outer surface of a liquid crystal cell, the polarizing plate containing the polarizing plate called H film which absorbed iodine, and extending | stretching polyvinyl alcohol between the cellulose acetate protective films, or the polarizing plate containing the H film itself is mentioned.

[Example]

Hereinafter, the present invention will be described more specifically by way of examples, but the present invention is not limited to these examples. The pretilt angle, voltage retention, liquid crystal wettability, printability, imidation ratio, and vertical alignment property in Examples and Comparative Examples were evaluated by the following method.

[Pre-tilt angle]

T. J. Scheffer, et. al., J. Appl. Phys., Vol. 19, 2013 (1980)] was measured by the crystal rotation method using a He-Ne laser light. Here, the pretilt angle is defined as an angle at which the alignment direction of the liquid crystal molecules is inclined at the substrate surface.

[Voltage retention rate]

After applying a voltage of 5 V to the liquid crystal display element at an application time of 60 microseconds and a span of 167 milliseconds, the voltage retention after 167 milliseconds from the release of the application was measured. The measurement apparatus used VHR-1 by Toyo Technica. It was judged that the case where the voltage retention was 98.5% or more was good, and the other cases were defective.

[Liquid crystal wettability]

Each liquid crystal aligning agent of this invention adjusted by the following Example and the comparative example was apply | coated using the spinner on the transparent conductive film which consists of an ITO film | membrane provided in one surface of the glass substrate, and it preliminarily for 1 minute at 80 degreeC on a hotplate. It dried and then baked at 210 degreeC for 10 minutes on the hotplate, and produced the liquid crystal aligning film of 60 nm in thickness. When the liquid crystal (MLC-6221 by Merck Co., Ltd.) was dripped on each alignment film, and the contact angle of the liquid crystal and the alignment film measured after 30 second after dripping becomes 14 degrees or less, wettability is favorable, and wettability is when the contact angle becomes larger than 14 degrees. It was judged to be defective.

Printability Test

200 nm of film thicknesses were carried out using the liquid crystal aligning film printer (made by Nippon Shashin Insatsugi Co., Ltd.) for each liquid crystal aligning agent (adjusted total solid content concentration to 6.9%) of this invention adjusted by the following example and the comparative example. A 20 µm wide ITO film was applied to a transparent electrode surface of a glass substrate with a transparent electrode formed in a stripe shape at intervals of 100 µm, preliminarily dried at 80 ° C on a hot plate for 1 minute, and then 210 ° C on a hot plate. After baking for 10 minutes to form a liquid crystal aligning film, the peripheral part and center part of this liquid crystal aligning film were observed with the microscope of 20 times the magnification, and the case where there was no application | coating nonuniformity was judged "good" and the case where application | coating nonuniformity was "defective". .

[Imidization rate]

After drying the polymer under reduced pressure at room temperature, tetramethylsilane was deuterated in deuterated dimethyl sulfoxide (DMSO-d ₆ ) using a superconducting nuclear magnetic resonance absorbing device (NMR, manufactured by Nippon Denshi Co., Ltd., trade name: EX-90A). ¹ H-NMR was measured as a reference substance. In the obtained data, the imidation ratio was calculated from the ratio of the peak area (proximate to 10 ppm) derived from the proton of NH group in a polymer, and the peak area derived from another proton.

[Vertical orientation]

The abnormal domain at the time of turning on / off the voltage under cross nicol to the liquid crystal display element was observed, and it was "good" and that there was no abnormal domain was made into "bad".

① horizontal For mode  Of liquid crystal aligning agent Example

Synthesis Example 1 (Synthesis of Polyimide A-1)

As tetracarboxylic dianhydride 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1, 2-c] furan-1,3-dione 11.7069 g (0.0372 mol), 8.3168 g (0.0371 mol) of 2,3,5-tricarboxycyclopentylacetic dianhydride, 7.0010 g p-phenylenediamine as a diamine compound (0.0647 Mole), 1.0275 g (0.0015 mole) of 4,4'-diamino-4 ''-heptadecafluorooctyltriphenylmethane represented by the formula (1-11), 3,3 '-(tetramethyldi 1.8440 g (0.0074 mol) of siloxane-1,3-diyl) bis (propylamine) and 0.1037 g (0.0011 mol) of aniline as a monoamine for terminal modification are dissolved in 70 g of N-methyl-2-pyrrolidone, 60 It was made to react at 6 degreeC. The reaction solution was then poured into a large excess of methyl alcohol to precipitate the reaction product. Thereafter, the resultant was washed with methyl alcohol and dried at 40 ° C. for 24 hours under reduced pressure to obtain 27.3 g of a polyamic acid having a logarithmic viscosity of 0.60 dl / g. 25 g of the obtained polyamic acid was dissolved in 225 g of N-methyl-2-pyrrolidone, and 24.5 g of pyridine and 25.3 g of acetic anhydride were added thereto, followed by dehydration and ring closure at 110 ° C. for 4 hours. Decompression was carried out to obtain 21.5 g of a polyimide having a logarithmic viscosity of 0.58 dl / g (this was referred to as "polyimide A-1").

Synthesis Example 2 (Synthesis of Polyimide A-2)

As tetracarboxylic dianhydride 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1, 2-c] furan-1,3-dione 11.3781 g (0.0362 mol), 2,3,5-tricarboxycyclopentylacetic dianhydride 8.0832 g (0.0361 mol), 6.6484 g p-phenylenediamine as a diamine compound (0.0615) Mole), 1.9974 g (0.0029 mole) of 4,4'-diamino-4 ''-heptadecafluorooctyltriphenylmethane represented by the formula (1-11), 3,3 '-(tetramethyldi 1.7922 g (0.0072 mole) of siloxane-1,3-diyl) bis (propylamine) and 0.1007 g (0.0011 mole) of aniline as a monoamine for terminal modification are dissolved in 70 g of N-methyl-2-pyrrolidone, 60 It was made to react at 6 degreeC. The reaction solution was then poured into a large excess of methyl alcohol to precipitate the reaction product. Thereafter, the resultant was washed with methyl alcohol and dried at 40 ° C. for 24 hours under reduced pressure to obtain 27.0 g of a polyamic acid having a logarithmic viscosity of 0.59 dl / g. 25 g of the obtained polyamic acid was dissolved in 225 g of N-methyl-2-pyrrolidone, 23.8 g of pyridine and 24.6 g of acetic anhydride were added to dehydrate and close the ring for 4 hours at 110 ° C. The decompression was performed to obtain 20.8 g of a polyimide having a logarithmic viscosity of 0.57 dl / g (this is referred to as "polyimide A-2").

Synthesis Example 3 (Synthesis of Polyamic Acid B-1)

1,2,3,4-cyclobutanetetracarboxylic dianhydride 196.12 g (1.0 mole) as tetracarboxylic dianhydride, 2,2'-dimethyl-4,4'-diaminobiphenyl 212.3 as a diamine compound g (1.0 mol) was dissolved in 4500 g of N-methyl-2-pyrrolidone and reacted at 40 ° C for 3 hours. The reaction solution was then poured into a large excess of methyl alcohol to precipitate the reaction product. Thereafter, the resultant was washed with methyl alcohol and dried at 40 ° C. for 24 hours to obtain 390 g of a polyamic acid having a logarithmic viscosity of 0.91 dl / g (referred to as "polyamic acid B-1").

Comparative Synthesis Example 1 (Synthesis of Polyimide A-3)

As tetracarboxylic dianhydride 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1, 2-c] furan-1,3-dione 11.6432 g (0.0370 mol), 2,3,5-tricarboxycyclopentyl acetic dianhydride 8.2715 g (0.0369 mol), 6.9429 g (0.0642 p-phenylenediamine as a diamine compound) Mole), 0.7117 g (0.0011 mole) of 3,6-bis (4-aminobenzoyloxy) cholestane represented by the following formula (18), 3,3 '-(tetramethyldisiloxane-1,3-diyl) bis (propyl) Amine) 1.8340 g (0.0074 mole) and 0.5967 g (0.0022 mole) stearylamine as a monoamine for terminal modification were dissolved in 70 g of N-methyl-2-pyrrolidone and reacted at 60 ° C for 18 hours. The reaction solution was then poured into a large excess of methyl alcohol to precipitate the reaction product. Thereafter, the resultant was washed with methyl alcohol and dried at 40 ° C. for 24 hours under reduced pressure to obtain 25.8 g of a polyamic acid having a logarithmic viscosity of 0.57 dl / g. 25 g of the obtained polyamic acid was dissolved in 225 g of N-methyl-2-pyrrolidone, 24.4 g of pyridine and 25.2 g of acetic anhydride were added to dehydrate and ring-close at 110 DEG C for 4 hours, and precipitated, washed, Decompression was carried out to obtain 19.8 g of a polyimide having a logarithmic viscosity of 0.55 dl / g (this was referred to as "polyimide A-3").

Comparative Synthesis Example 2 (Synthesis of Polyimide A-4)

19.8674 g (0.0886 mol) of 2,3,5-tricarboxycyclopentylacetic dianhydride as tetracarboxylic dianhydride, 9.4403 g (0.0873 mol) of p-phenylenediamine as a diamine compound, 3, 0.6923 g (0.0013 mol) of 5-diaminobenzoic acid = cholest-5-en-3-yl was dissolved in 70 g of N-methyl-2-pyrrolidone, and reacted at 60 degreeC for 4 hours. The reaction solution was then poured into a large excess of methyl alcohol to precipitate the reaction product. Thereafter, the resultant was washed with methyl alcohol and dried at 40 ° C. for 24 hours under reduced pressure to obtain 26.4 g of a polyamic acid having a logarithmic viscosity of 0.65 dl / g. 25 g of the obtained polyamic acid was dissolved in 225 g of N-methyl-2-pyrrolidone, and 29.2 g of pyridine and 22.6 g of acetic anhydride were added thereto, followed by dehydration and ring closure at 110 ° C. for 4 hours. Decompression was carried out to obtain 18.8 g of a polyimide having a logarithmic viscosity of 0.62 dl / g (this was referred to as "polyimide A-4").

Example 1

The polyimide (A-1) obtained in Synthesis Example 1 and the polyamic acid (B-1) obtained in Synthesis Example 3 were each γ such that polyimide (A-1): polyamic acid (Bl) = 20:80 (weight ratio). Dissolve in a butyrolactone / N-methyl-2-pyrrolidone / ethylene glycol monobutyl ether mixed solvent (solvent weight ratio 71/17/12) and further N, N, N ', N'-tetraglyci 2 weight% of diyl-4,4'-diaminodiphenylmethane with respect to the total amount of polyimide (A-1) and polyamic acid (B-1), and 3-glycidoxypropyltrimethoxysilane as polyimide ( 1 wt% was added to the total amount of A-1) and the polyamic acid (B-1), respectively, to obtain a TN type liquid crystal aligning agent having a total solid concentration of 3.5 wt% (however, the printability test was performed as described above). At this time, the total solid content concentration was adjusted to the TN type liquid crystal aligning agent which is 6.9 weight%). After fully stirring this, it filtered using the filter of 1 micrometer of pore diameters, and adjusted the liquid crystal aligning agent of this invention. The said liquid crystal aligning agent is apply | coated using a spinner on the transparent conductive film containing the ITO film | membrane provided on one surface of the glass substrate, preliminary drying for 1 minute at 80 degreeC on a hotplate, and then at 210 degreeC on a hotplate is carried out. By baking for 10 minutes, the transparent electrode substrate which has a liquid crystal aligning film with a film thickness of 60 nm was manufactured. By the rubbing machine which has the roll which wound the cloth made from rayon on this film, the rubbing process was performed once by the roll rotation speed of 400 rpm, the movement speed of 30 mm / sec of a stage, and 0.4 mm of bristle indentation lengths. The liquid crystal aligning film coated substrate was ultrasonically cleaned in pure water for 1 minute, and then dried in a clean oven at 100 ° C for 10 minutes. Next, after apply | coating the aluminum oxide sphere containing epoxy resin adhesive of diameter 5.5micrometer to each outer edge which has a liquid crystal aligning film of the said liquid crystal aligning film coating board | substrate of a pair of transparent electrode / transparent electrode board | substrate, so that a liquid crystal aligning film surface may mutually face each other. Overlaid and pressed to cure the adhesive. Subsequently, after filling a nematic liquid crystal (MLC-6221 made by Merck Co., Ltd.) between a liquid crystal injection hole and a board | substrate, the liquid crystal injection hole is sealed with an acryl-type photocuring adhesive agent, a polarizing plate is bonded by the outer both sides of a board | substrate, and a TN type liquid crystal display element Was prepared. Table 1 shows the results of evaluating the pretilt angle and voltage retention of the obtained TN type liquid crystal display device.

Example 2

A TN type liquid crystal display device was obtained in the same manner as in Example 1 except that the polyimide (A-2) obtained in Synthesis Example 2 was used instead of the polyimide (A-1). Table 1 shows the results of evaluating the pretilt angle and voltage retention of the obtained TN type liquid crystal display device.

Comparative Example 1

A TN type liquid crystal display element was obtained in the same manner as in Example 1 except that the polyimide (A-3) obtained in Comparative Synthesis Example 1 was used instead of the polyimide (A-1). Table 1 shows the results of evaluating the pretilt angle and the voltage retention of the obtained TN type liquid crystal display device.

Comparative Example 2

TN type liquid crystal display elements were obtained in the same manner as in Example 1 except that only polyimide (A-4) obtained in Comparative Synthesis Example 1 was used instead of polyimide (A-1) and polyamic acid (B-1). Table 1 shows the results of evaluating the pretilt angle and voltage retention of the obtained TN type liquid crystal display device.

From the said Table 1, it is clear that the TN type liquid crystal aligning film obtained from the TN type liquid crystal aligning agent obtained by Example 1 and Example 2 has favorable liquid crystal wettability compared with what was obtained by the comparative example, expressing a high pretilt angle. It is clear that the pretilt angle and liquid crystal wettability of the TN type liquid crystal aligning film obtained from the TN type liquid crystal aligning agent of the present invention can be adjusted by the selection of the diamine structure containing the fluorine atom represented by the formula (1) and the copolymerization composition of the monomer. Do. As mentioned above, it is possible to provide the TN type liquid crystal display element which has a beautiful image which has the TN type liquid crystal aligning agent which was excellent in liquid crystal wettability, and the said alignment film, and expresses a desired high pretilt angle by this invention.

② VA For mode  Of liquid crystal aligning agent Example

Synthesis Example 4

5.2034 g (0.0232 mol) of 2,3,5-tricarboxycyclopentylacetic dianhydride as tetracarboxylic dianhydride, 2.0366 g (0.0188 mol) of p-phenylenediamine as a diamine compound and the above formula (1-11) 3.260 g (0.0047 mol) of the indicated 4,4'-diamino-4 ''-heptadecafluorooctyltriphenylmethane are dissolved in 42 g of N-methyl-2-pyrrolidone and 4 hours at 60 ° C. Reacted. The reaction solution was then poured into a large excess of methyl alcohol to precipitate the reaction product. Thereafter, the resultant was washed with methyl alcohol and dried at 40 ° C. for 24 hours to obtain 9.25 g of a polyamic acid having a logarithmic viscosity of 0.71 dl / g (which is referred to as "P-1").

Synthesis Example 5

9.0 g of polyamic acid synthesized in exactly the same manner as in Synthesis example 4 was dissolved in 120 g of N-methyl-2-pyrrolidone, and 1.58 g of pyridine and 2.03 g of acetic anhydride (both pyridine and acetic anhydride were added to the repeating unit of the polyamic acid). 1 equivalent) was added and dehydrated and closed for 4 hours at 110 ° C. Precipitation, washing | cleaning, and pressure_reduction | reduction were carried out similarly to the synthesis example 4, and 7.1 g of imidation polymers (it is referred to as "P-2") of logarithmic viscosity 0.68 dl / g and imidation ratio 51% were obtained.

Comparative Synthesis Examples 3 to 5

Except for changing the tetracarboxylic dianhydride and the diamine compound to those shown in Table 2, polymers of logarithmic viscosity and imidation ratio shown in Table 2 in the same manner as in Synthesis Example 3 and Synthesis Example 4 (these are "P-3" to "P-5" was obtained. On the other hand, "P-3" is a polyamic acid and was not imidized.

In addition, in Table 2, acid dianhydride A, B, and diamine A, B show the following compounds, respectively.

Acid dianhydride A: 2,3,5-tricarboxycyclopentyl acetic dianhydride

Acid dianhydride B: pyromellitic dianhydride

Diamine A: Diamine compound represented by the following general formula (20)

Diamine B: p-phenylenediamine

Example 3

N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether are mixed with the polyamic acid (P-1) obtained in Synthesis Example 4 by weight ratio of N-methyl-2-pyrrolidone / ethylene glycol monobutyl ether = 30/70. To 20% by weight of N, N, N ', N'-tetraglycidyl-4,4'-diaminodiphenylmethane based on polyamic acid (P-1). It was set as 3.5 weight% VA type liquid crystal aligning agent (However, when performing a printing test, it was set as VA type liquid crystal aligning agent whose total solid content concentration is 6.9 weight%). After sufficiently stirring this, it filtered using the filter of 1 micrometer of pore diameters, and apply | coated using a spinner on the transparent conductive film which consists of an ITO film | membrane provided in one surface of the glass substrate, and preliminarily for 1 minute at 80 degreeC on a hotplate. It dried and then baked at 200 degreeC in clean oven (in nitrogen atmosphere) for 1 hour, and the transparent electrode substrate which has a liquid crystal aligning film with a film thickness of 60 nm was manufactured. Next, after apply | coating the aluminum oxide sphere containing epoxy resin adhesive of diameter 5.5micrometer to each outer edge which has a liquid crystal aligning film of the said liquid crystal aligning film coating board | substrate of a pair of transparent electrode / transparent electrode board | substrate, so that a liquid crystal aligning film surface may oppose each other. Overlaid and pressed to cure the adhesive. Subsequently, a negative liquid crystal (MLC-2038, manufactured by Merck Co., Ltd.) was filled between the substrates from the liquid crystal inlet, and then the liquid crystal inlet was sealed with an acrylic photocuring adhesive to prepare a VA type liquid crystal display element.

Table 3 shows the results of evaluating the pretilt angle and vertical alignment property of the obtained VA type liquid crystal display device.

Example 4

N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether were replaced with N-methyl-2-pyrroly by using the imidized polymer (P-2) obtained in Synthesis Example 5 instead of the polyamic acid (P-1). A VA type liquid crystal display device was obtained in the same manner as in Example 3 except that the ton / ethylene glycol monobutyl ether mixture weight ratio was 50/50. Table 3 shows the results of evaluating the pretilt angle and vertical alignment property of the obtained VA type liquid crystal display device.

Comparative Example 3

A VA type liquid crystal display device was obtained in the same manner as in Example 3 except that the polyamic acid (P-3) obtained in Comparative Synthesis Example 3 was used instead of the polyamic acid (P-1). Table 3 shows the results of evaluating the pretilt angle and vertical alignment property of the obtained VA type liquid crystal display device.

Comparative Example 4

Instead of the polyamic acid (P-1), N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether were replaced with N-methyl-2-pi using the imidized polymer (P-4) obtained in Comparative Synthesis Example 4 A VA type liquid crystal display device was obtained in the same manner as in Example 3 except that the weight ratio of 50 to 50 of the mixture of ralidone / ethylene glycol monobutyl ether was obtained. Table 3 shows the results of evaluating the pretilt angle and vertical alignment property of the obtained VA type liquid crystal display device.

Comparative Example 5

Instead of the polyamic acid (P-1), N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether were replaced with N-methyl-2-pi using the imidized polymer (P-5) obtained in Comparative Synthesis Example 5 A VA type liquid crystal display device was obtained in the same manner as in Example 3 except that the weight ratio of ralidone / ethylene glycol monobutyl ether was set to 50/50. Table 3 shows the results of evaluating the pretilt angle and vertical alignment property of the obtained VA type liquid crystal display device.

It is clear that the VA type liquid crystal aligning film obtained from the VA type liquid crystal aligning agent obtained in Example 3 and Example 4 from the said Table 3 shows the outstanding vertical alignment property, and its liquid-crystal wettability is favorable compared with what was obtained by Comparative Examples 3-5. It is clear that the liquid crystal wettability of the VA type liquid crystal aligning film obtained from the VA type liquid crystal aligning agent of this invention can be adjusted by the selection of the diamine structure which has a substituent containing the fluorine atom represented by the said Formula (1), and the copolymerization composition of the said monomer. . As mentioned above, according to this invention, it is possible to provide the VA type liquid crystal display element which has the VA type liquid crystal aligning agent which is excellent in the wettability of a liquid crystal, and the said alignment film, and has a beautiful image.

According to the liquid crystal aligning agent of this invention, the desired pretilt angle of 1-90 degrees is provided and the liquid crystal aligning film excellent in liquid crystal wettability is obtained. Especially the liquid crystal aligning agent of this invention can be used suitably for liquid crystal display elements, such as TN mode, STN mode, OCB mode, and VA mode.

Claims (5)

Dehydration of the polyamic acid and the polyamic acid obtained by reacting the first diamine represented by the following formula (1) and the second diamine represented by the following formula (2) with the tetracarboxylic dianhydride represented by the following formula (3) A liquid crystal aligning agent containing at least one of the imidation polymer produced | generated by ring-closure. &Lt; Formula 1 >

(Wherein R ₁ and R ₂ are each independently a hydrogen atom; a halogen atom; a substituted or unsubstituted carbon atom having 1 to 30 carbon atoms which may have a linking group including an oxygen atom, a nitrogen atom, a sulfur atom or a silicon atom); Hydrocarbon group or polar group, provided that 5 R ₂ may be the same or different, and at least one of R ₁ and 5 R ₂ is a substituent including a fluorine atom) <Formula 2> H ₂ NR ₃ -NH ₂ (Wherein R ₃ is a divalent organic group) <Formula 3>

(Wherein R ₄ is a tetravalent organic group) The liquid crystal aligning agent of Claim 1 whose one or more of the groups represented by R <_2> in General formula (1) is a C2 or more fluorinated alkyl group. The tetracarboxylic dianhydride represented by the formula (3) is 2,3,5-tricarboxycyclopentylacetic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 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, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2 , 5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride or pyromelli Liquid crystal aligning agent which is dianhydride. The liquid crystal aligning agent of Claim 1 used for TN mode, STN mode, OCB mode, or VA mode. The liquid crystal aligning film formed from the liquid crystal aligning agent in any one of Claims 1-4 is provided, The liquid crystal display element characterized by the above-mentioned.