TWI386435B - Vertical alignment mode liquid crystal alignment agent and vertical alignment mode liquid crystal display device - Google Patents

Description

Vertical alignment type liquid crystal alignment agent and vertical alignment type liquid crystal display element

The present invention relates to a novel vertical alignment type liquid crystal alignment agent and a vertical alignment type liquid crystal display element. More specifically, it relates to a novel vertical alignment type liquid crystal alignment agent having a structure derived from a specific tetracarboxylic acid dianhydride having an aromatic ketone structure, excellent in image resistance, and a vertical alignment type liquid crystal display element having a beautiful image.

From the perspective of space saving, low power consumption, etc., liquid crystal display elements represented by liquid crystal displays have been applied to watches, portable game consoles, word processors, notebook computers, etc. since mass production of liquid crystal calculators. Automobile navigators, cameras, PDAs, digital cameras, mobile phones, various monitors, LCD TVs, etc. are still in active development. As a display method of the prior art, a TN (Twisted Nematic) type and an STN (Super Twisted Nematic) type have been widely used. In recent years, in order to improve the display quality of a liquid crystal display, a liquid crystal using negative dielectric anisotropy has been developed. When a voltage is applied, the liquid crystal molecules are vertically aligned parallel to the substrate surface by a VA (Vertical Alignment) type. Compared with the TN type and the STN type, the VA type does not increase the brightness of the backlight, and thus can obtain a high contrast ratio, and generally does not require a rubbing process, and therefore is used for applications requiring a display having high display quality. (especially mobile phones and LCD TVs, etc.). In addition, a vertical alignment type liquid crystal display element, which is an MVA (Multi Domain Vertical Alignment) type and a PVA (Patterned Vertical Alignment) type, which has improved high viewing angle characteristics, has been proposed, and the use of the VA type has been further expanded. However, since the VA type liquid crystal display element is used for applications requiring high-quality display performance, it is required to have a higher level of resistance (reliability) of the display panel afterimage caused by charge accumulation during long-term continuous driving. Now, there is an urgent need to establish techniques for strategies to further reduce image loss.

In the vertical alignment type liquid crystal display element, the alignment of the liquid crystal is generally as described in Patent Documents 1 to 3 by polymerization of at least one polymer containing a polyamic acid selected from a substituent having a bulky side chain and a ruthenium-imidized polymer. The vertical alignment type liquid crystal alignment film formed by the liquid crystal alignment agent of the object is controlled. Since the liquid crystal alignment film is a member that directly contacts the liquid crystal molecules, it is known that it has a very large influence on the afterimage (charge accumulation) and voltage holding ratio of the liquid crystal display element, and thus it is urgent to develop a vertical alignment type liquid crystal by improvement. A means for aligning the film to improve the image sticking resistance of the liquid crystal display element. For example, Patent Document 4 and Patent Document 5 disclose an example of optimizing the composition of the vertical alignment type liquid crystal alignment film from the viewpoint of easily diffusing the accumulated electric charge and shortening the afterimage erasing time. With the demand for greatly improving the image resistance of the vertical alignment type liquid crystal display element as described above, it is urgent to develop the same liquid crystal alignment agent capable of producing a vertical alignment type liquid crystal alignment film which is more difficult to generate charge.

[Patent Document 1] Japanese Patent Laid-Open No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. 2003-295194. [Patent Document 5] Japanese Patent Laid-Open Publication No. 2004-94179

The present invention has been made based on the above circumstances. Accordingly, an object of the present invention is to provide a vertical alignment type liquid crystal alignment agent which exhibits excellent vertical alignment and which can produce a vertical alignment type liquid crystal alignment film excellent in image retention.

According to the present invention, the above object of the present invention is achieved by a vertical alignment type liquid crystal alignment agent characterized by containing an aromatic ketone represented by the following formula (1-1) and formula (1-2). At least one first tetracarboxylic acid dianhydride (wherein, a and b are independently an integer of 0 to 3, and R ₁ to R ₁₂ independently represent a hydrogen atom; a halogen atom; optionally a linking group having an oxygen atom, a sulfur atom, a nitrogen atom or a halogen atom; a substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms; or a polar group, wherein a group of two adjacent groups selected from R ₁ to R ₆ and R ₇ to R ₁₂ are respectively linked to each other Forming a carboxylic anhydride group) (wherein X represents a single bond, a sulfur atom, an oxygen atom, a methyl group having 1 to 3 carbon atoms, a carbonyl group (-CO-), a sulfonyl group (-SO ₂ -), an imido group (-NH) Any of -), c and d are independently an integer of 0 to 3, and R ₁₃ to R ₂₄ independently represent a hydrogen atom; a halogen atom; optionally having a connection with an oxygen atom, a sulfur atom, a nitrogen atom or a halogen atom; a substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms; or a polar group, wherein a group of 2 adjacent groups selected from R ₁₃ to R ₁₈ and R ₁₉ to R ₂₄ respectively a second tetracarboxylic acid dianhydride which is different from the first tetracarboxylic acid dianhydride represented by the following formula (2), each of which is bonded to each other to form a carboxylic anhydride group) (wherein R ₂₅ is a tetravalent organic group) the first diamine represented by the following formula (3) (wherein, e is 0 or 1, and R ₂₆ is a divalent organic compound selected from the group consisting of -O-, -CO-, -COO-, -OCO-, -NHCO-, -CONH-, -S-, and methyl. a group, R ₂₇ is a divalent organic group different from R ₂₆ , and R ₂₈ is a group selected from a group having a steroid skeleton, a group having a fluorine atom or a linear alkyl group having 1 to 22 carbon atoms. a group of a group) and a second diamine H ₂ N-R ₂₉ -NH ₂ (4) different from the first diamine represented by the following formula (4) (wherein R ₂₉ is 2 Valence organic group)

The polylysine obtained by the reaction and/or the ruthenium-imided polymer obtained by dehydrating the polyamic acid is closed.

Further, according to the present invention, the above object of the present invention is achieved by a vertical alignment type liquid crystal display element having a vertical alignment type liquid crystal alignment film formed of the above-described vertical alignment type liquid crystal alignment agent.

According to the vertical alignment type liquid crystal alignment agent of the present invention, a vertical alignment type liquid crystal alignment film excellent in vertical alignment and image resilience can be obtained, and a vertical alignment type liquid crystal display element capable of producing a beautiful image can be obtained from the liquid crystal alignment film. .

[Polyuric acid and ruthenium iodide polymer]

Hereinafter, the present invention will be specifically described. The polyamic acid to be used in the present invention can be obtained by subjecting the tetracarboxylic dianhydride represented by the above formula (1-1) and/or (1-2) to the above formula (2) to the above formula (3) and the above formula ( 4) The resulting diamine addition polymerization reaction is carried out. Further, the ruthenium iodide polymer used in the present invention can be obtained by dehydration ring closure of the above polyglycine.

[tetracarboxylic dianhydride]

The vertical alignment type liquid crystal alignment agent of the present invention can be (co)polymerized by using at least one selected from the group consisting of tetracarboxylic dianhydrides represented by the above formulas (1-1) and (1-2) as tetracarboxylic dianhydride. Excellent resistance to image retention.

In the present invention, the ratio of the tetracarboxylic acid dianhydride represented by each of the above formulae (1-1) and (1-2) is preferably from 5 to 90 mol% based on the total tetracarboxylic acid dianhydride, more preferably 7~75 mol%, especially good 10~60 mol%. When the ratio of the tetracarboxylic dianhydride represented by each of the above formulas (1-1) and (1-2) is too small, it is difficult to obtain sufficient resistance to image sticking, and if too large, the coloring property of the alignment agent may become problematic. Case.

A hydrogen atom represented by R ₁ to R ₂₄ in the above formulas (1-1) and (1-2); a halogen atom; a substituent optionally having a linking group containing an oxygen atom, a sulfur atom, a nitrogen atom or a halogen atom; Or an unsubstituted monovalent hydrocarbon group having 1 to 30 carbon atoms; and a monovalent polar group.

The halogen atom may, for example, be a fluorine atom, a chlorine atom or a bromine atom. Examples of the monovalent hydrocarbon group having 1 to 30 carbon atoms include an alkyl group such as a methyl group, an ethyl group, and a propyl group; a cycloalkyl group such as a cyclopentyl group or a cyclohexyl group; and an alkenyl group such as a vinyl group or an allyl group; An alkylene group such as an ethylene group or a propylene group; an aromatic group such as a phenyl group, a naphthyl group, an anthracenyl group, a biphenyl group or a fluorenyl group; and the like. The hydrogen atom bonded to the carbon atom in these groups may be optionally substituted by a halogen atom such as fluorine, chlorine or bromine, a cyano group or the like.

Further, the above substituted or unsubstituted monovalent hydrocarbon group may be directly bonded or attached to the benzene ring structure represented by the formula (1-1) and/or the formula (1-2) via a linking group. The above linking group may, for example, be a linking group containing an oxygen atom, a nitrogen atom, a sulfur atom or a halogen atom (for example, a carbonyl group (-CO-), a carbonyloxy group (-COO-), or an oxycarbonyl group (-OCO-). ), sulfonyl (-SO ₂ -), sulfonyloxy (-SO ₂ -O-), oxysulfonyl (-O-SO ₂ -), ether linkage (-O-), thioether bond (-S-), an imido group (-NH-), a guanamine bond (-NHCO-), a decane bond (-Si(R) ₂ O-) (wherein R is a methyl group, an ethyl group, etc.) a group in which two or more of them are bonded in combination. When the above substituted or unsubstituted monovalent hydrocarbon group is a cycloalkyl group or an aromatic group, the above linking group may also have a carbon number. It is a divalent hydrocarbon group of 1 to 10 (for example, -(CH ₂ ) _m - (wherein m is an alkyl group represented by an integer of 1 to 10)).

The monovalent polar group may, for example, be a hydroxyl group, a cyano group, a nitro group, a decylamino group, an imido group (=NH), a triorganomethoxy group, a triorganoalkyl group, an amine group, a decyl group or an alkoxy group. Based on an alkyl group, a sulfonic acid group (-SO ₃ H), a sulfinyl group (-SO ₂ H), a carboxyl group, and the like.

More specifically, examples of the triorganomethoxy group include a trimethylphosphonium group and a triethylphosphonium group. Examples of the triorganoalkylene group include a trimethylsulfanyl group and a triethylsulfanyl group; and examples of the amine group include a secondary amino group and a tertiary amino group, and examples of the alkoxyalkylene group include, for example, an alkoxyalkylene group. Trimethoxydecyl, triethoxydecyl, and the like.

Wherein, in the above formula (1-1), a and b are independently an integer of 0 to 3, and a group of two adjacent groups selected from R ₁ to R ₆ and R ₇ to R ₁₂ are respectively connected to each other. A carboxylic anhydride group is formed. Here, a and b are preferably in the range of 0 ≦ a + b ≦ 3, and more preferably a = b =0.

Further, in the above (1-2), X represents a single bond, a sulfur atom, an oxygen atom, an alkylene group having 1 to 3 carbon atoms, a carbonyl group (-CO-), a sulfonyl group (-SO ₂ -), Any one of the imido groups (-NH-), c and d are independently an integer of 0 to 3, and a group of two adjacent groups selected from R ₁₃ to R ₁₈ and R ₁₉ to R ₂₄ respectively Interconnected to form a carboxylic anhydride group. Here, c and d are preferably in the range of 0 ≦ c + d ≦ 3, and more preferably c = d = 0.

Specific examples of the tetracarboxylic dianhydride which are each represented by the above formulas (1-1) and (1-2) include the following compounds.

3,3',4,4'-benzophenonetetracarboxylic acid dianhydride represented by the following formula (A-1), 2,3,3',4'-benzophenonetetracarboxylic acid dianhydride represented by the following formula (A-2), 2,2',3,3'-benzophenonetetracarboxylic acid dianhydride represented by the following formula (A-3), 2,3,6,7-(9-fluorenone)tetracarboxylic acid dianhydride represented by the following formula (A-4), 2,3,6,7-(9-thioxanthone)tetracarboxylic acid dianhydride represented by the following formula (A-5),

As described above, the first tetracarboxylic dianhydride may be used singly or in combination of two or more kinds.

Examples of the second tetracarboxylic acid dianhydride different from the first tetracarboxylic acid dianhydride represented by the above formulas (1-1) and (1-2) include butane tetracarboxylic acid dianhydride and 1, 2 , 3,4-cyclobutane tetracarboxylic acid 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-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-tetramethyl- 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride, 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride , 3,3',4,4'-dicyclohexyltetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 3,5,6-tricarboxynorbornane-2-acetic acid Diacid anhydride, 2,3,4,5-tetrahydrofuran tetracarboxylic acid dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furan -Naphthalene [1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-5-methyl-5-(tetrahydro-2,5 -dioxo-3-furanyl)-naphthalene[1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-5-ethyl-5 -(tetrahydro-2,5-dioxo-3- Furyl)-naphthalene [1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-7-methyl-5-(tetrahydro-2, 5-dioxo-3-furanyl)-naphthalene[1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-7-ethyl- 5-(tetrahydro-2,5-dioxo-3-furanyl)-naphthalene[1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b- Hexahydro-8-methyl-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphthalene[1,2-c]-furan-1,3-dione, 1,3, 3a,4,5,9b-hexahydro-8-ethyl-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphthalene[1,2-c]-furan-1,3 -dione, 1,3,3a,4,5,9b-hexahydro-5,8-dimethyl-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphthalene [1 ,2-c]-furan-1,3-dione, 5-(2,5-dioxotetrahydrofuranmethylene)-3-methyl-3-cyclohexene-1,2-dicarboxylic acid Anhydride, bicyclo[2,2,2]-oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 3-oxabicyclo[3.2.1]octane-2,4-dione -6-spiro-3'-(tetrahydrofuran-2',5'-dione), 3,5,6-tricarboxy-2-carboxynorbornane-2:3,5 6-dianhydride, bicyclo[3.3.0]octane-2,4,6,8-tetracarboxylic acid dianhydride, compounds represented by the following formulas (7) and (8), etc., aliphatic and alicyclic four Carboxylic acid dianhydride; (wherein R ₃₀ and R ₃₂ represent a divalent organic group having an aromatic ring, R ₃₁ and R ₃₃ represent a hydrogen atom or an alkyl group, and a plurality of R ₃₁ and R _{33 present} may be the same or different); Pyromellitic dianhydride, 3,3',4,4'-diphenylphosphonium tetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7- Naphthalene tetracarboxylic acid dianhydride, 3,3',4,4'-diphenyl ether tetracarboxylic acid dianhydride, 3,3',4,4'-dimethyldiphenylnonane tetracarboxylic acid dianhydride, 3,3',4,4'-tetraphenylnonanetetracarboxylic acid dianhydride, 1,2,3,4-furan tetracarboxylic acid dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy Diphenyl sulfide dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenylsebacic anhydride, 4,4'-bis(3,4-dicarboxyphenoxy Diphenylpropane dianhydride, 3,3',4,4'-perfluoroisopropylidene di phthalic acid dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, two (phthalic acid) phenylphosphine oxide dianhydride, p-phenylene-bis(triphenylphthalic acid) dianhydride, m-phenylene-bis(triphenylphthalic acid) dianhydride, di Triphenylphthalic acid)-4,4'-diphenyl ether dianhydride, di(triphenylene) Tetraphthalic acid)-4,4'-diphenylmethane dianhydride, ethylene glycol-di(hydrogen trimellitate), propylene glycol-di(hydrogen trimellitate), 1,4-butane Alcohol-di(hydrogen trimellitate), 1,6-hexanediol-di(anhydrotrimellitic acid ester), 1,8-octanediol-di(hydrogen trimellitate), 2, An aromatic tetracarboxylic dianhydride such as a compound represented by 2-(4-hydroxyphenyl)propane-di(hydrogen trimellitate) or a compound represented by the following formulas (9) to (11).

Among them, preferred butane tetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, and 1,3-dimethyl-1 are preferred from the viewpoint of exhibiting good liquid crystal alignment. , 2,3,4-cyclobutane tetracarboxylic acid dianhydride, 1,2,3,4-cyclopentane tetracarboxylic acid dianhydride, 1,2,4,5-cyclohexane tetracarboxylic acid dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 5-(2,5-dioxotetrahydrofuranmethylene)-3-methyl-3-cyclohexene-1,2-dicarboxylic acid Anhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphthalene[1,2-c]-furan-1, 3-diketone, 1,3,3a,4,5,9b-hexahydro-8-methyl-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphthalene [1,2 -c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-5,8-dimethyl-5-(tetrahydro-2,5-dioxo- 3-furyl)-naphthalene[1,2-c]-furan-1,3-dione, bicyclo[2,2,2]-oct-7-ene-2,3,5,6-tetracarboxylic acid Diacid anhydride, 3-oxabicyclo[3.2.1]octane-2,4-dione-6-spiro-3'-(tetrahydrofuran-2',5'-dione), 3,5,6-three Carboxy-2-carboxynorbornane 2:3,5:6-dianhydride, bicyclo[3.3.0]octane-2,4,6,8-tetracarboxylic dianhydride, pyromellitic dianhydride, 3,3',4,4 '-diphenylphosphonium tetracarboxylic acid dianhydride, 1,4,5,8-naphthalenetetracarboxylic acid dianhydride, and each of the following formulas (12) to (14) in the compound represented by the above formula (7) A compound represented by the following formula (15) in the compound and the compound represented by the above formula (8). Particularly preferred examples thereof include 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride and 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride. 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 1,3,3a,4,5,9b-hexahydro-5-( Tetrahydro-2,5-dioxo-3-furanyl)-naphthalene[1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro- 8-methyl-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphthalene[1,2-c]-furan-1,3-dione, 3-oxabicyclo[3.2 .1] Octane-2,4-dione-6-spiro-3'-(tetrahydrofuran-2',5'-dione), 3,5,6-tricarboxy-2-carboxynorbornane-2 : 3,5:6-dianhydride, bicyclo[3.3.0]octane-2,4,6,8-tetracarboxylic dianhydride, pyromellitic dianhydride, and a compound represented by the following formula (12) .

The above-mentioned second tetracarboxylic dianhydride may be used singly or in combination of two or more kinds.

[diamine compound]

The liquid crystal alignment agent of the present invention can exhibit excellent vertical alignment by copolymerizing an appropriate amount of the diamine represented by the above formula (3). The ratio of the diamine represented by the above formula (3) is preferably from 8 to 60 mol%, more preferably from 9 to 50 mol%, particularly preferably from 10 to 25 mol%, based on the total of the diamine. When the ratio of the diamine represented by the above formula (3) is too small, it is difficult to obtain sufficient vertical alignment property, and if it is too large, coating of pinholes or the like may occur when the alignment film is formed.

In the above formula (3), e is 0 or 1, and R ₂₆ is selected from an ether bond (-O-), a carbonyl group (-CO-), a carbonyloxy group (-COO-), an oxycarbonyl group (-OCO-). ), a guanamine bond (-NHCO-, -CONH-), a thioether bond (-S-), and a divalent organic group of a methyl group. Among them, an ether bond (-O-) or a carbonyloxy group (-COO-) is particularly preferred. R ₂₇ is a divalent organic group different from R ₂₆ , and preferably a divalent linking group having an aromatic group or a cyclohexyl group. Further, R ₂₈ is a group selected from the group consisting of a group having a steroid skeleton, a group having a fluorine atom, or a group having a linear alkyl group having 1 to 22 carbon atoms.

Specific examples of the diamine represented by the above formula (3) include the compounds listed below.

Among them, from the viewpoint of exhibiting excellent vertical alignment, it is particularly preferable to be (C-1) and (C-2). Further, the first diamine may be used singly or in combination of two or more kinds.

The second diamine compound represented by the above formula (4) is a diamine other than the first diamine, and specific examples thereof include p-phenylenediamine, m-phenylenediamine, and 4,4'-diamino group. Diphenylmethane, 4,4'-diaminodiphenylethane, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenylanthracene, 2,2'-dimethyl Base-4,4'-diaminobiphenyl, 4,4'-diaminobenzimidamide, 4,4'-diaminodiphenyl ether, 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'-diaminodiphenyl ether, 3,3'-diaminobenzophenone, 3,4' -diaminobenzophenone, 4,4'-diaminobenzophenone, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2-di ( 4-aminophenyl)hexafluoropropane, 2,2-bis[4-(4-aminophenoxy)phenyl]anthracene, 2,2-bis[4-(4-aminophenoxy) Phenyl]propane, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy) ) Benzene, 9,9 Bis(4-aminophenyl)-10-hydroquinone, 2,7-diaminopurine, 9,9-bis(4-aminophenyl)anthracene, 4,4'-methyl-di-( 2-chloroaniline), 2,2',5,5'-tetrachloro-4,4'-diaminobiphenyl, 2,2'-dichloro-4,4'-diamino-5,5 '-Dimethoxybiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 1,4,4'-(p-phenylene isopropylidene)diphenylamine, 4,4'-(m-phenylene isopropylidene)diphenylamine, 2,2'-bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]hexafluoropropane , 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl, 4,4'-diamino-2,2'-dimethylbiphenyl, 4,4'- Di[(4-amino-2-trifluoromethyl)phenoxy]-octafluorobiphenyl, 1,3-bis(4-aminophenoxy)-2,2-dimethylpropane, 4 , 4'-bis(4-aminophenoxy)biphenyl, 1,3-bis(4-aminophenoxy)-2,2-dimethylpropane, 4,4'-di(4- Aromatic diamines such as 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)pyridazine, 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-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-ethoxyacridinyl lactate, 3,8-diamine Benzyl-6-phenylphenanthridine, 1,4-diaminopyridazine, 3,6-diaminoacridine, bis(4-aminophenyl)phenylamine, and the following formula (16), 17) a diamine having two primary amine groups and a nitrogen atom other than the primary amine group in a molecule such as a compound represented by each; (wherein R ₃₄ represents a monovalent organic group having a cyclic structure containing a nitrogen atom selected from the group consisting of pyridine, pyrimidine, triazine, acridine and pyridazine, and X represents a divalent organic group) (wherein R ₃₅ represents a divalent organic group having a cyclic structure containing a nitrogen atom selected from the group consisting of pyridine, pyrimidine, triazine, acridine and pyridazine); 1,3-bis(aminomethyl)cyclohexane , 1,3-propanediamine, butanediamine, pentanediamine, hexamethylenediamine, heptanediamine, octanediamine, decanediamine, 4,4-diaminoheptanediamine, 1,4-diamine Cyclohexane, isophoronediamine, tetrahydrodicyclopentadienyldiamine, hexahydro-4,7-methylene quinone dimethylenediamine, tricyclo[6.2.1.0 ^2,7 ]- An aliphatic and alicyclic diamine such as undecylene dimethyl diamine, 4,4′-methyl bis(cyclohexylamine); a diamine organic oxirane represented by the following formula (18); (wherein R ₃₆ represents a hydrocarbon group having 1 to 12 carbon atoms, and a plurality of R ₃₆ present may be the same or different, p is an integer of 1 to 3, and q is an integer of 1 to 20). These 2nd diamines can be used individually or in combination of 2 or more types.

Among them, preferred p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfide, 1,5-diaminonaphthalene, 2,7-diamine Base, 4,4'-diaminodiphenyl ether, 9,9-bis(4-aminophenyl)anthracene, 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, a compound represented by the following formula (19) and a compound represented by the following formula (20) in the compound represented by the above formula (17), and a compound represented by the following formula (16); 3-di(aminomethyl)cyclohexane, 1,4-cyclohexanediamine, 4,4'-methyl-di(cyclohexylamine), the following formula in the compound represented by the above formula (18) 3,3'-(Tetramethyldioxane-1,3-diyl)bis(propylamine) represented by (21).

Particularly preferred are p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diamino-2,2'-dimethylbiphenyl, 4,4'. -diaminodiphenyl ether, 3,3'-(tetramethyldioxane-1,3-diyl)di(propylamine), 2,2-bis[4-(4-aminophenoxyl) Phenyl]propane, 1,3-bis(aminomethyl)cyclohexane, 2,2-bis(4-aminophenyl)hexafluoropropane, 4,4'-diamino-2, 2'-bis(trifluoromethyl)biphenyl, 2,7-diaminoguanidine.

<Synthesis of polylysine>

The use ratio of the tetracarboxylic acid dianhydride and the diamine compound used in the polyproline acid synthesis reaction of the present invention is preferably such that the acid anhydride group of the tetracarboxylic acid dianhydride is based on the amino group contained in one equivalent of the diamine compound. The ratio of 0.2 to 2 equivalents is more preferably a ratio of 0.3 to 1.2 equivalents.

The synthesis reaction of polylysine is carried out in an organic solvent preferably at a temperature of from -20 to 150 ° C, more preferably from 0 to 100 ° C. Here, the organic solvent is not particularly limited as long as it can dissolve the synthesized polyaminic acid, and examples thereof include N-methyl-2-pyrrolidone, N,N-dimethylacetamide, and N,N. - aprotic polar solvents such as dimethylformamide, dimethyl hydrazine, γ-butyrolactone, tetramethylurea, hexamethylphosphonium triamine; m-methylphenol, xylenol, phenol, halogen A phenolic solvent such as phenol may be used, and these solvents may be used alone or in combination of two or more. Further, the amount (a) of the organic solvent is preferably such that the total amount (b) of the tetracarboxylic acid dianhydride and the diamine compound is from 0.1 to 30% by weight based on the total amount (a+b) of the reaction solution.

Further, in the range in which the produced polyamine acid is not precipitated, a poor solvent alcohol, a ketone, an ester, an ether, a halogenated hydrocarbon, and a hydrocarbon of polyglycine may be used in combination in the above organic solvent. Wait. Specific examples of such a poor solvent include methanol, ethanol, isopropanol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, diacetone alcohol, and ethylene glycol. Methyl ether, ethyl lactate, butyl lactate, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, methyl methoxypropionate, Ethyl ethoxypropionate, propylene carbonate, diethyl oxalate, diethyl malonate, diethyl ether, ethylene glycol methyl ether, ethylene glycol ether, ethylene glycol n-propyl ether, ethylene glycol isopropyl ether Ethylene glycol monobutyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diglyme, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, two Glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, tetrahydrofuran, dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloro Ethane, chlorobenzene, o-dichlorobenzene, hexane, heptane, octane, benzene, toluene, xylene, and the like. These poor solvents may be used singly or in combination of two or more kinds.

As described above, a reaction solution in which polylysine was dissolved was obtained. Then, the reaction solution is poured into a large amount of a poor solvent and/or water to obtain a precipitate, and then the precipitate is dried under reduced pressure to obtain a polyamic acid. Further, the poly-proline is redissolved in an organic solvent, and then precipitated with a poor solvent and/or water, and the poly-proline can be purified by performing one or several processes.

<醯iminated polymer>

The quinone imidized polymer used in the liquid crystal alignment agent of the present invention can be synthesized by dehydrating and ring-closing the above polyamic acid. (The so-called quinone imidized polymer herein includes a partially yttrium-imidized polymer partially yt-imidized with the above polyamic acid and a 100% quinned imidized polymer, hereinafter, collectively referred to as "醯亚Aminated polymer").

The oxime imidization ratio of the ruthenium iodide polymer used in the liquid crystal alignment agent of the present invention is preferably from 10 to 100%, more preferably from 20 to 80%, particularly preferably from 25 to 60%. Here, the "rhodium imidization ratio" means a value expressed by % with respect to the ratio of the number of repeating units forming a quinone ring to the total number of repeating units in the polymer. At this time, a part of the quinone ring may also be an isoindole ring.

As a method for synthesizing the ruthenium-imidized polymer, (I) a method of synthesizing by dehydration ring closure by heating the above polyamic acid, and (II) dissolving the polylysine in an organic solvent, A method in which a dehydrating agent and a dehydration ring-closure catalyst are added to the solution and heated to carry out dehydration ring closure as needed is carried out, and by appropriately controlling the above reaction conditions, a polymer having a desired quinone imidization ratio can be obtained.

The reaction temperature of the above method (I) for heating poly-proline is preferably from 50 to 300 ° C, more preferably from 100 to 250 ° C. When the reaction temperature is less than 50 ° C, the dehydration ring-closure reaction cannot be completed. If the reaction temperature exceeds 300 ° C, the molecular weight of the obtained ruthenium-imided polymer may be lowered.

On the other hand, in the method of adding a dehydrating agent and a dehydration ring-closure catalyst to the polyamic acid solution of the above (II), an acid anhydride such as acetic anhydride, propionic anhydride or trifluoroacetic anhydride can be used as the dehydrating agent. The amount of the dehydrating agent is preferably 0.01 to 20 moles per 1 mole of the polyamido acid repeating unit. Further, as the dehydration ring-closure catalyst, a tertiary amine such as pyridine, trimethylpyridine, lutidine or triethylamine can be used. However, the dehydrating agent and the dehydration ring-closing catalyst are not limited to these examples. The amount of the dehydration ring-closing catalyst is preferably from 0.01 to 10 mols per mol of the dehydrating agent used. In addition, examples of the organic solvent used in the dehydration ring-closure reaction include the same organic solvents as those exemplified as the solvent used in the synthesis of polylysine. Further, the reaction temperature of the dehydration ring closure reaction is preferably from 0 to 180 ° C, more preferably from 60 to 150 ° C. Further, the ruthenium iodide polymer can be purified by performing the same operation as the polyamic acid purification method on the reaction solution thus obtained.

<End modified polymer>

The polyamic acid and the quinone imidized polymer constituting the liquid crystal alignment agent of the present invention may also be a terminal modified polymer having a molecular weight adjusted. By using the terminal-modified polymer, the coating properties and the like of the liquid crystal alignment agent can be improved without impairing the effects of the present invention. Such a terminal-modified polymer can be synthesized by adding a monobasic acid anhydride, a monoamine compound, a monoisocyanate compound or the like to the reaction system in the synthesis of polyamic acid. Here, examples of the monobasic acid anhydride include a dicarboxylic acid monobasic acid anhydride, and examples thereof include maleic anhydride, phthalic anhydride, itaconic anhydride, n-decyl succinic anhydride, n-dodecyl succinic anhydride, and n-tetradecyl group. Succinic anhydride, n-hexadecyl succinic anhydride, and the like. Further, examples of the monoamine compound include aniline, cyclohexylamine, p-ethylaniline, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-decylamine, n-decylamine, and n- Monoalkylamine, n-dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecaneamine, n-octadecylamine, n-icosane Amines, etc. Further, examples of the monoisocyanate compound include phenyl isocyanate and naphthyl isocyanate.

<Logarithmic Viscosity of Polymer>

The logarithmic viscosity (η ln ) value of the polylysine and the quinone imidized polymer obtained as above is preferably from 0.05 to 10 dl/g, more preferably from 0.05 to 5 dl/g.

The logarithmic viscosity (η ln) value in the present invention is obtained by measuring the viscosity of a solution having a concentration of 0.5 g/100 ml at 30 ° C by using N-methyl-2-pyrrolidone as a solvent, and obtaining the viscosity of the following formula (a). value.

<Liquid alignment agent>

The liquid crystal alignment agent of the present invention is preferably constituted by dissolving a composition of a polyamic acid and a ruthenium iodide polymer in an organic solvent. In order to improve the electrical properties of residual DC and the coating film property at the time of formation of an alignment film, the liquid crystal alignment agent of the present invention may further contain no respective derived from the above formulas (1-1) and (1-2) when the alignment agent is adjusted. The structure of the tetracarboxylic acid dianhydride represented by the above and the polyaminic acid and/or quinone imidized polymer derived from the structure of the first diamine represented by the above formula (3). The structure containing no tetracarboxylic dianhydride represented by each of the above formulas (1-1) and (1-2) and the polyamine derivative derived from the structure of the first diamine represented by the above formula (3) and/or Or a hydrazine imidized polymer, which may be one type or plural kinds, preferably poly-proline, depending on the purpose, particularly preferably selected from 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1 , 3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 2,3,5-tricarboxyl ring Amyl acetal dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphthalene [1,2-c]- Furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-8-methyl-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphthalene [1,2-c]-furan-1,3-dione, 3-oxabicyclo[3.2.1]octane-2,4-dione-6-spiro-3'-(tetrahydrofuran-2', 5'-dione), 3,5,6-tricarboxy-2-carboxynorbornane-2:3,5:6-dianhydride, bicyclo[3.3.0]octane-2,4,6, More than one acid dianhydride of 8-tetracarboxylic dianhydride or pyromellitic dianhydride and selected from p-phenylenediamine, 4, 4'- Aminodiphenylmethane, 4,4'-diaminodiphenyl sulfide, 1,5-diaminonaphthalene, 2,7-diaminopurine, 4,4'-diaminodiphenyl ether, 9 ,9-bis(4-aminophenyl)anthracene, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-di[4-(4-aminobenzene) Oxy)phenyl]hexafluoropropane, 2,2-bis(4-aminophenyl)hexafluoropropane, 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl More than one diamine of 4,4'-diamino-2,2'-dimethylbiphenyl, 3,3-(tetramethyldioxane-1,3-diyl)di(propylamine) The resulting polylysine is reacted. a polyglycine containing a structure derived from a tetracarboxylic dianhydride represented by each of the above formulas (1-1) and/or (1-2) and a structure derived from the first diamine represented by the above formula (3) And/or a ruthenium imidized polymer (which is referred to as a polymer "X"), and a structure containing no tetracarboxylic dianhydride derived from each of the above formulas (1-1) and (1-2) and derived from the above The mixing ratio of the above polyamic acid and/or quinone imidized polymer (which is a polymer "Y") of the structure of the first diamine represented by the formula (3), preferably X/Y by weight Range of =10/90~90/10, better range of X/Y=15/85~60/40, especially good range of X/Y=20/80~50/50.

The temperature at which the liquid crystal alignment agent of the present invention is prepared is preferably from 0 ° C to 200 ° C, more preferably from 10 ° C to 100 ° C, particularly preferably from 20 ° C to 60 ° C.

The organic solvent constituting the liquid crystal alignment agent of the present invention may be the same solvent as exemplified as the solvent used in the synthesis reaction of polylysine. Among them, a solvent having a boiling point of 160 ° C or higher is preferable from the viewpoint of printability, and examples thereof include N-methyl-2-pyrrolidone, N,N-dimethylacetamide, dimethyl hydrazine, and γ-. Butyrolactone, tetramethylurea, trimethylamine hexamethylphosphite, m-methylphenol, 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), two Glyme, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, 1,4-dichloro Butane, o-dichlorobenzene, etc. Among them, preferred are N-methyl-2-pyrrolidone, γ-butyrolactone, diacetone alcohol, ethylene glycol monobutyl ether (butyl cellosolve), propylene carbonate, and diethylene glycol diethyl ether. A particularly preferable solvent composition is a composition obtained by combining the above solvents, and is a composition in which the polymer in the alignment agent is not precipitated and the surface tension of the alignment agent is in the range of 25 to 40 mN/m.

The solid content concentration in the liquid crystal alignment agent of the present invention is selected in consideration of viscosity, volatility, etc., and is preferably in the range of 1 to 10% by weight. That is, the liquid crystal alignment agent of the present invention is applied to the surface of the substrate to form a coating film as a liquid crystal alignment film. When the solid content concentration is less than 1% by weight, the thickness of the coating film is too small, so that a good liquid crystal alignment cannot be obtained. When the solid content concentration exceeds 10% by weight, the thickness of the coating film is too thick, so that a good liquid crystal alignment film cannot be obtained, and the viscosity of the liquid crystal alignment agent is increased, and the coating property is deteriorated.

The viscosity of the liquid crystal alignment agent of the present invention (the viscosity obtained by measuring the liquid crystal alignment agent at 25 ° C by a rotary viscometer) needs to be appropriately adjusted according to the method of applying the alignment agent, preferably 3 to 100 mPa. s, more preferably 3~50mPa. s, especially good for 3~35mPa. The scope of s.

Further, a particularly preferable solid content concentration range differs depending on the method used when the liquid crystal alignment agent is applied to the substrate. For example, when the spin coating method is employed, it is particularly preferably in the range of 1.5 to 4.5% by weight. When using the printing method, it is particularly preferable to make the concentration of the solid component in the range of 3 to 9 wt%, so that the viscosity of the solution falls within 12 to 50 mPa. The scope of s. When using the inkjet method, it is particularly preferable to make the concentration of the solid component in the range of 1 to 5% by weight, so that the viscosity of the solution falls between 3 and 15 mPa. The scope of s.

The liquid crystal alignment agent of the present invention may further contain a functional decane-containing compound or an epoxy group-containing compound from the viewpoint of improving adhesion to the surface of the substrate. As such a functional decane-containing compound, for example, 3-aminopropyltrimethoxydecane, 3-aminopropyltriethoxydecane, 2-aminopropyltrimethoxydecane, and 2-amine can be mentioned. Propyltriethoxydecane, N-(2-aminoethyl)-3-aminopropyltrimethoxydecane, N-(2-aminoethyl)-3-aminopropylmethyl Dimethoxydecane, 3-ureidopropyltrimethoxydecane, 3-ureidopropyltriethoxydecane, N-ethoxycarbonyl-3-aminopropyltrimethoxydecane, N-ethoxy Carbonyl-3-aminopropyltriethoxydecane, N-triethoxydecylpropyltriethylamine, N-trimethoxydecylpropyltriethylamine, 10-trimethyl Oxidylalkyl-1,4,7-triazadecane, 10-triethoxydecyl-1,4,7-triazadecane, 9-trimethoxydecyl-3,6- Diazepine acetate, 9-triethoxydecyl-3,6-diazaindolyl acetate, N-benzyl-3-aminopropyltrimethoxydecane, N-benzyl 3-aminopropyltriethoxydecane, N-phenyl-3-aminopropyltrimethoxy Decane, N-phenyl-3-aminopropyltriethoxydecane, 3-glycidoxypropyltrimethoxydecane, N-bis(oxyethylene)-3-aminopropyltrimethoxy Decane, N-bis(oxyethylene)-3-aminopropyltriethoxydecane, and the like.

Further, as the epoxy group-containing compound, preferred are, for example, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, and polypropylene glycol dihydrate. Glycerol ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerol 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-bi-dihydrate Glycerylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, and the like. The mixing ratio of the functional decane-containing compound and the epoxy group-containing compound is preferably 60 parts by weight or less based on 100 parts by weight of the total amount of the polyamic acid and/or the ruthenium-based polymer. It is preferably 50 parts by weight 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 alignment agent of the present invention is applied onto one surface of a substrate provided with a patterned transparent conductive film by a method such as a roll coater method, a spin coating method, a printing method, or an inkjet method, and then passed through The coated surface is heated to form a coating film. Here, as a method of applying a liquid crystal alignment agent to a substrate, a spin coating method is preferred for a small substrate, a printing method is preferred for a medium substrate, and an inkjet method is preferred for a large substrate. As the substrate, for example, glass such as float glass or soda lime glass; plastic such as polyethylene terephthalate, polybutylene terephthalate, polyether oxime, polycarbonate, or cyclic polyolefin can be used. A transparent substrate is produced. As the transparent conductive film provided on one side of the substrate, a NESA film made of tin oxide (SnO ₂ ) (registered trademark of PPG, USA), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ -SnO ₂ ), or the like can be used. . The patterning of these transparent conductive films is performed by photolithography and a method of using a mask in advance. As the reflective electrode, a metal such as Al or Ag, an alloy containing these metals, or the like can be used. However, as long as it has sufficient reflectance, it is not limited to these. In the coating of the liquid crystal alignment agent, in order to further improve the adhesion between the substrate surface and the transparent conductive film or the reflective electrode and the coating film, a functional decane-containing compound or a functional titanium-containing compound may be previously coated on the surface of the substrate. Compounds, etc. After the liquid crystal alignment agent is applied, preheating (prebaking) is usually performed for the purpose of preventing the coating agent liquid from sagging or the like. The prebaking temperature is preferably from 30 to 300 ° C, more preferably from 40 to 200 ° C, and particularly preferably from 50 to 150 ° C. Then, the solvent is completely removed, and a aging (post-baking) process is carried out in order to heat-imidize the polyglycolic acid into a polyimine. The curing temperature is preferably from 80 to 300 ° C, more preferably from 120 to 250 ° C. As described above, the liquid crystal alignment agent of the present invention containing polyglycine is removed by applying an organic solvent to form a coating film as an alignment film, and by further heating to perform dehydration ring closure, a coating film which is further imidized can be formed. The thickness of the formed coating film is preferably 0.001 to 1 μm, more preferably 0.005 to 0.5 μm.

(2) The rubbing treatment can be performed by rubbing a surface of the formed coating film with a cloth wrapped with a cloth made of a fiber such as nylon, rayon, cotton or the like in a certain direction, and the alignment angle of the liquid crystal molecules can also be controlled. Further, in addition to the method of polishing, it is also possible to employ a method of irradiating the surface of the coating film with polarized ultraviolet light to control the alignment energy. Further, in order to remove the fine powder (foreign matter) generated during the polishing treatment or the like, and to clean the surface of the coating film, it is preferred to wash the formed liquid crystal alignment film with isopropyl alcohol and/or pure water. In addition, as for the liquid crystal alignment film which is formed by the liquid crystal alignment agent of the present invention, a process of partially irradiating ultraviolet rays to change the pretilt angle, as shown in Japanese Laid-Open Patent Publication No. Hei. 6-222366, No. Hei 6-281937, Alternatively, a protective film is partially formed on the liquid crystal alignment film subjected to the rubbing treatment as shown in JP-A-5-107544, and the protective film is removed in a direction different from the previous polishing treatment to remove the protective film. The treatment of the alignment of the alignment film can be changed, which can improve the visual field characteristics of the liquid crystal display element.

(3) Two substrates in which the liquid crystal alignment film is formed as described above are formed, and two substrates are placed opposite each other through a gap (cell gap), and the peripheral portions of the two substrates are bonded together with a sealant to the surface of the substrate and the sealant. The divided cell gap is filled with liquid crystal, and the injection hole is closed to form a liquid crystal cell. Then, a polarizing plate is provided on the outer surface of the liquid crystal cell, that is, on the outer surface of each of the substrates constituting the liquid crystal cell, to obtain a liquid crystal display element.

Here, as the sealant, for example, an alumina ball-containing epoxy resin or the like as a curing agent and a separator can be used.

Examples of the liquid crystal include nematic liquid crystal and disc liquid crystal. Among them, a nematic liquid crystal is preferable, and for example, a Schiff base liquid crystal, an azo azo liquid crystal, a biphenyl liquid crystal, a phenylcyclohexane liquid crystal, an ester liquid crystal, a terphenyl liquid crystal, or a biphenyl group can be used. A cyclohexane liquid crystal, a pyrimidine liquid crystal, a dioxane liquid crystal, a bicyclooctane liquid crystal, a cubic liquid crystal, or the like. Further, in these liquid crystals, cholesteric liquid crystal such as cholesteryl cholesteryl, cholesteryl phthalate or cholesteryl carbonate may be added, and the trade names "C-15" and "CB-15" (manufactured by Merck & Co., Inc.) may be added. It is used by selling chiral agents and the like. Further, a ferroelectric liquid crystal such as p-methoxybenzylidene-p-amino-2-methylbutylcinnamate may also be used.

In addition, as a polarizing plate to be bonded to the outer surface of the liquid crystal cell, a polarizing plate or H which is obtained by sandwiching a polarizing film called an H film obtained by stretching a polyvinyl alcohol and absorbing iodine at the same time may be used. A polarizing plate made of the film itself.

Example

Hereinafter, the present invention will be more specifically described by way of examples, but the invention is not limited to the examples. In the examples and comparative examples, the vertical alignment property, the image retention resistance, and the printability were evaluated by the following methods.

[Vertical alignment] is on. When the voltage is cut off, the presence or absence of an abnormal region of the liquid crystal display element is observed by a crossed Nicol prism, and the abnormal region is "good", and the abnormal region is "not good".

[Resistance resistance] After applying a DC voltage of 17 V to the liquid crystal display element for 20 hours in an environment of 100 ° C, the application of the voltage was released, and after attenuating for 15 minutes in a room temperature environment, the inside of the liquid crystal cell was determined by a scintillation elimination method. Residual voltage (residual DC voltage). When the residual DC voltage value is smaller, it is determined that the liquid crystal display element having the anti-image resistance is determined, and if the residual liquid crystal display element having a DC voltage value of 600 mV or less is judged to have "resistance", the residual DC voltage value is higher than 600 mV. It is judged that the anti-image resistance is "not good".

[Printability Experiment] A liquid crystal alignment film (manufactured by Nippon Photo Printing Co., Ltd.) was used, and the liquid crystal alignment agent of the present invention (the liquid crystal alignment agent having a total solid concentration of 6.5%) was applied thereto. The transparent electrode surface of a glass substrate of a strip-shaped transparent electrode formed of an ITO film having a thickness of 200 nm and a width of 20 μm at intervals of 100 μm was pre-dried on a hot plate at 80 ° C for 1 minute, and then The film was aged in a clean oven (under a nitrogen atmosphere) at 200 ° C for 1 hour to form a liquid crystal alignment film. The peripheral portion and the central portion of the liquid crystal alignment film were observed with a microscope at a magnification of 20, and it was judged as "good" when there was no coating unevenness, and "not good" when there was uneven coating. The evaluation results of the printability of each of the alignment agents are shown in Table 2.

Synthesis Example 1 3,289,289 g (0.1025 mol) of 3,3',4,4'-benzophenonetetracarboxylic acid dianhydride as tetracarboxylic acid dianhydride and 2,3,5-tricarboxycyclopentylacetic acid 22.9777 g (0.1025 mol) of an acid anhydride, 17.1477 g (0.0519 mol) of diamine represented by the above formula (C-1) as a diamine compound, and 16.8457 g (0.1558 mol) of p-phenylenediamine dissolved in 400 g of N- The reaction was carried out at 60 ° C for 4 hours in methyl-2-pyrrolidone. Next, the reaction solution was poured into a large excess of methanol to precipitate a reaction product. Then, it was washed with methanol, and dried at 40 ° C for 24 hours under reduced pressure to obtain 87 g of polyamic acid having a logarithmic viscosity of 0.62 dl / g. This polyamic acid is referred to as "P-1".

Synthesis Example 2 47.1326 g (0.1463 mol) of 2,3',4,4'-benzophenonetetracarboxylic acid dianhydride as tetracarboxylic acid dianhydride and 2,3,5-tricarboxycyclopentyl acetic acid 10.9298 g (0.0488 mol) of an acid anhydride, 25.8791 g (0.0495 mol) of diamine represented by the above formula (C-1) as a diamine compound, and 16.0585 g (0.1485 mol) of p-phenylenediamine dissolved in 400 g of N- The reaction was carried out at 60 ° C for 4 hours in methyl-2-pyrrolidone. Next, the reaction solution was poured into a large excess of methanol to precipitate a reaction product. Then, it was washed with methanol, and dried at 40 ° C for 24 hours under reduced pressure to obtain 91 g of polylysine having a logarithmic viscosity of 0.65 dl / g. This polyamic acid is referred to as "P-2".

Synthesis Example 3 1,0.6586 g (0.0331 mol) of 3,3',4,4'-benzophenonetetracarboxylic acid dianhydride as tetracarboxylic acid dianhydride, and 2,3,5-tricarboxycyclopentylacetic acid 42.0184 g (0.1874 mol) of an acid anhydride, 29.2024 g (0.0559 mol) of diamine represented by the above formula (C-1) as a diamine compound, and 18.1206 g (0.1676 mol) of p-phenylenediamine dissolved in 400 g of N- The reaction was carried out at 60 ° C for 4 hours in methyl-2-pyrrolidone. Next, the reaction solution was poured into a large excess of methanol to precipitate a reaction product. Then, it was washed with methanol, and dried at 40 ° C for 24 hours under reduced pressure to obtain 85 g of polylysine having a logarithmic viscosity of 0.58 dl / g. This polyamic acid is referred to as "P-3".

Synthesis Examples 4 to 7, Comparative Synthesis Examples 1 to 3 were obtained in the same manner as in Synthesis Examples 1 to 3 except that the tetracarboxylic acid dianhydride and the diamine compound were replaced with those described in Table 1, and the polyfluorene shown in Table 1 was obtained. Amino acids and polyimines (these are referred to as "P-4" to "P-10"). Further, in Table 1, the acid dianhydrides A to D and the diamines E to G represent the following compounds, respectively.

Acid dianhydride A: 3,3',4,4'-benzophenonetetracarboxylic acid dianhydride dianhydride B: 2,2',3,3'-benzophenonetetracarboxylic acid dianhydride dianhydride C : 2,3,5-tricarboxycyclopentyl acetic acid dianhydride acid dianhydride D: pyromellitic acid dianhydride diamine E: diamine compound diamine F represented by the above formula (C-1): the above formula (C -2) Deamine compound represented by diamine G: p-phenylenediamine

Comparative Synthesis Example 4: 18.7189 g (0.0835 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride as a tetracarboxylic acid dianhydride, and a diamine represented by the above formula (C-1) as a diamine compound 8.9096 g (0.0170 mol) and p-phenylenediamine 7.3715 g (0.0682 mol) were dissolved in 140 g of N-methyl-2-pyrrolidone and reacted at 60 ° C for 4 hours. Next, the reaction solution was poured into a large excess of methanol to precipitate a reaction product. Then, it was washed with methanol, and dried at 40 ° C for 24 hours under reduced pressure to obtain 32 g of polylysine having a logarithmic viscosity of 0.65 dl / g. 30.0 g of the polyproline was dissolved in 400 g of N-methyl-2-pyrrolidone, and 5.67 g of pyridine and 7.30 g of acetic anhydride (pyridine, acetic anhydride and 1 unit of repeating unit of polyglycolic acid) were added. Dehydration closed at 110 ° C for 4 hours. This was precipitated, washed, and reduced in pressure in the same manner as above to obtain 24.4 g of a ruthenium iodide polymer having a logarithmic viscosity of 0.62 dl/g and a ruthenium iodide ratio of 51% (this is referred to as "P-11"). .

Example 1 Addition of N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether to poly-proline (P-1) prepared in Synthesis Example 1 to make N-methyl-2-pyrrolidone/B The weight ratio of diol monobutyl ether is 40/60, and 20% by weight of N,N,N',N'-tetraglycidyl-4,4 is added relative to polyglycine (P-1). '-Diaminodiphenylmethane, a liquid crystal alignment agent having a total solid concentration of 3.5% by weight was prepared (however, when a printability test was carried out, a liquid crystal alignment agent having a total solid concentration of 6.5% by weight) was prepared. After thoroughly stirring the mixture, it was filtered through a filter having a pore size of 0.2 μm, coated on a transparent conductive film made of an ITO film provided on one surface of a glass substrate by a spin coater, and pre-dried at 80 ° C for 1 minute on a hot plate. Subsequently, it was aged in a clean oven (under a nitrogen atmosphere) at 200 ° C for 1 hour to prepare a transparent electrode substrate having a liquid crystal alignment film having a film thickness of 60 nm. Then, on each of the outer edges of the pair of transparent electrode/transparent electrode substrates on which the liquid crystal alignment film is coated, a liquid crystal alignment film is coated with an epoxy resin adhesive to which alumina balls having a diameter of 5.5 μm are applied. Then, the liquid crystal alignment film surface is relatively recombined and pressed to cure the adhesive. Next, a negative liquid crystal (MLC-2038, manufactured by Merck & Co., Inc.) was filled between the substrates through a liquid crystal injection port, and then the liquid crystal injection port was sealed with an acrylic photocurable adhesive to prepare a liquid crystal display element. The results of evaluation of the vertical alignment property and the image sticking resistance of the obtained liquid crystal display element are shown in Table 2.

Example 2 An alignment agent and a liquid crystal display element of the present invention were obtained in the same manner as in Example 1 except that the polyamic acid (P-2) obtained in Synthesis Example 2 was used instead of polyglycine (P-1). . The results of evaluation of the vertical alignment property and the image sticking resistance of the obtained liquid crystal display element are shown in Table 2.

Example 3 An alignment agent and a liquid crystal display element of the present invention were obtained in the same manner as in Example 1 except that polylysine (P-3) obtained in Synthesis Example 3 was used instead of polyglycine (P-1). . The results of evaluation of the vertical alignment property and the image sticking resistance of the obtained liquid crystal display element are shown in Table 2.

Example 4 An alignment agent and a liquid crystal display element of the present invention were obtained in the same manner as in Example 1 except that polylysine (P-4) obtained in Synthesis Example 4 was used instead of polyglycine (P-1). . The results of evaluation of the vertical alignment property and the image sticking resistance of the obtained liquid crystal display element are shown in Table 2.

Example 5 except that polylysine (P-5) prepared in Synthesis Example 5 was used instead of polyglycine (P-1), a mixture of N-methyl-2-pyrrolidone/ethylene glycol monobutyl ether. The alignment agent and liquid crystal display element of the present invention were obtained in the same manner as in Example 1 except that the weight ratio was 30/70. The results of evaluation of the vertical alignment property and the image sticking resistance of the obtained liquid crystal display element are shown in Table 2.

Example 6 except that polylysine (P-6) prepared in Synthesis Example 6 was used instead of polyglycine (P-1), a mixture of N-methyl-2-pyrrolidone/ethylene glycol monobutyl ether. The alignment agent and liquid crystal display element of the present invention were obtained in the same manner as in Example 1 except that the weight ratio was 30/70. The results of evaluation of the vertical alignment property and the image sticking resistance of the obtained liquid crystal display element are shown in Table 2.

Example 7 except that polylysine (P-7) prepared in Synthesis Example 7 was used instead of polylysine (P-1), and N, N, N', N'-tetraglycidyl group was not added - An alignment agent and a liquid crystal display element of the present invention were obtained in the same manner as in Example 1 except for 4,4'-diaminodiphenylmethane. The results of evaluation of the vertical alignment property and the image sticking resistance of the obtained liquid crystal display element are shown in Table 2.

Comparative Example 1 except that polylysine (P-10) prepared in Comparative Synthesis Example 3 was used instead of polylysine (P-1), N-methyl-2-pyrrolidone/ethylene glycol monobutyl ether. An alignment agent and a liquid crystal display element were produced in the same manner as in Example 1 except that the mixing weight ratio was 30/70. The results of evaluation of the vertical alignment property and the image sticking resistance of the obtained liquid crystal display element are shown in Table 2.

Comparative Example 2, except that the ruthenium imidized polymer (P-11) obtained in Comparative Synthesis Example 4 was used instead of polylysine (P-1), N-methyl-2-pyrrolidone/ethylene glycol monobutyl An alignment agent and a liquid crystal display element were produced in the same manner as in Example 1 except that the weight ratio of the ether was changed to 50/50. The results of evaluation of the vertical alignment property and the image sticking resistance of the obtained liquid crystal display element are shown in Table 2.

As is apparent from the above Table 2, the liquid crystal alignment films obtained from the liquid crystal alignment agents obtained in Examples 1 to 7 exhibited excellent vertical alignment properties, and were more resistant to image sticking than those obtained in Comparative Examples 1 and 2. it is good. It is shown that the anti-image resistance of the vertical alignment type liquid crystal alignment film obtained by the liquid crystal alignment agent of the present invention can be at least one of containing an aromatic ketone represented by the above formula (1-1) and formula (1-2). The structure of the tetracarboxylic dianhydride structure is selected and the copolymerization composition of the monomer is adjusted. As described above, according to the present invention, it is possible to provide a vertical alignment type liquid crystal alignment agent which exhibits excellent vertical alignment property and excellent in image retention resistance, and a vertical alignment type liquid crystal display element having the alignment film and having a beautiful image.

Claims (5)

A vertical alignment type liquid crystal alignment agent containing at least one first tetracarboxylic acid dianhydride selected from the aromatic ketones represented by the following formulas (1-1) and (1-2), and the following formula (2) a second tetracarboxylic acid dianhydride different from the first tetracarboxylic acid dianhydride, a first diamine represented by the following formula (3), and a first diamine represented by the following formula (4) a polyaminic acid obtained by a different second diamine reaction and/or a ruthenium-imided polymer obtained by dehydrating and ring-closing the polyamic acid, Wherein a and b are independently an integer of 0 to 3, and R ₁ to R ₁₂ independently represent a hydrogen atom; a halogen atom; a substituent optionally having a linking group containing an oxygen atom, a sulfur atom, a nitrogen atom or a ruthenium atom; Or an unsubstituted hydrocarbon group having 1 to 30 carbon atoms; or a monovalent polar group in which a group of two adjacent groups selected from R to R ₆ and R ₇ to R ₁₂ are each mutually Connecting to form a carboxylic anhydride group, In the formula, X represents a single bond, a sulfur atom, an oxygen atom, an alkylene group having 1 to 3 carbon atoms, a carbonyl group (-CO-), a sulfonyl group (-SO ₂ -), an imido group (-NH-). Any one of them, c and d are independently an integer of 0 to 3, and R ₁₃ to R ₂₄ independently represent a hydrogen atom; a halogen atom; optionally a linking group having an oxygen atom, a sulfur atom, a nitrogen atom or a halogen atom; The substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms; or a monovalent polar group. Wherein a group of two adjacent groups selected from R ₁₃ to R ₁₈ and R ₁₉ to R ₂₄ are each bonded to each other to form a carboxylic anhydride group; Wherein R ₂₅ is a tetravalent organic group; Wherein e is 0 or 1, and R ₂₆ is selected from the group consisting of an ether bond (-O-), a carbonyl group (-CO-), a carbonyloxy group (-COO-), an oxycarbonyl group (-OCO-), a guanamine bond. (-NHCO-, -CONH-), a thioether bond (-S-), a divalent organic group of a methyl group, R ₂₇ is a divalent organic group different from R ₂₆ , and R ₂₈ is selected from the group consisting of ruthenium a group of a body skeleton, a group having a fluorine atom, or a group having a group having a linear alkyl group having 1 to 22 carbon atoms; H ₂ N-R ₂₉ -NH ₂ (4) R ₂₉ is a divalent organic group. The vertical alignment type liquid crystal alignment agent of the first aspect of the invention, wherein the ratio of the first tetracarboxylic acid dianhydride to the total amount of the first tetracarboxylic dianhydride and the second tetracarboxylic dianhydride is 5~ 90% by mole. The vertical alignment type liquid crystal alignment agent of claim 1 or 2, wherein the first tetracarboxylic dianhydride is selected from the group consisting of 3,3',4,4'-benzophenonetetracarboxylic acid dianhydride, 2,3,3',4'-benzophenonetetracarboxylic acid dianhydride, 2,2',3,3'-benzophenone tetracarboxylic acid dianhydride, at least one tetracarboxylic acid dianhydride, second tetracarboxylic acid The acid dianhydride is selected from the group consisting of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 1,2,3,4-cyclobutane tetracarboxylic dianhydride, 1,3-dimethyl-1,2, 3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphthalene [ 1,2-c]-furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-8-methyl-5-(tetrahydro-2,5-dioxo- 3-furyl)-naphthalene [1,2-c]-furan-1,3-dione, 3,5,6-tricarboxy-2-carboxynorbornane-2:3,5:6-dianhydride And at least one tetracarboxylic acid dianhydride of bicyclo[3.3.0]octane-2,4,6,8-tetracarboxylic acid dianhydride. The vertical alignment type liquid crystal alignment agent of any one of the above-mentioned formula (3), wherein the first diamine represented by the above formula (3) is each of the following formula (5) or the following formula (6) At least one of the diamines having a steroid skeleton, A vertical alignment type liquid crystal display element comprising a vertical alignment type liquid crystal alignment film formed of a vertical alignment type liquid crystal alignment agent according to any one of claims 1 to 4.