TWI679221B - Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element - Google Patents

Abstract

The present invention provides a liquid crystal display element capable of appropriately exhibiting various characteristics in a well-balanced manner. In the present invention, a polymer (P) having a partial structure represented by the following formula (1) is contained in a liquid crystal alignment agent. (In formula (1), R ¹ is a tetravalent organic group, and R ² is a divalent organic group; X ¹ and X ² are each independently a hydroxyl group or a monovalent organic group having 1 to 40 carbon atoms; wherein X ¹ and At least one of X ² is a monovalent organic group having an aromatic amine structure, a heterocyclic group, and a polymerizable group selected from two or more aromatic rings directly bonded to a nitrogen atom. And light rearranged groups)

Description

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

The invention relates to a liquid crystal alignment agent, a liquid crystal alignment film and a liquid crystal display element.

In the past, liquid crystal display elements have developed various driving methods such as electrode structures or the physical properties and manufacturing steps of liquid crystal molecules used, such as known twisted nematic (TN) type or super twisted nematic (Super Twisted Nematic, STN), Vertical Alignment (VA), In-Plane Switching (IPS), fringe field switching (FFS) and other liquid crystal display elements. These liquid crystal display elements have a liquid crystal alignment film for aligning liquid crystal molecules. In terms of various characteristics such as heat resistance, mechanical strength, and affinity with liquid crystals, polyamic acid or polyimide is generally used as a material of the liquid crystal alignment film.

In addition, in recent years, a liquid crystal alignment agent using polyamidate for at least a part of a polymer component has been proposed (for example, refer to Patent Document 1). Patent Document 1 discloses that polyamidate and polyamidate are contained in a liquid crystal alignment agent as polymer components, and that the polyamidate has a weight-average molecular weight smaller than that of polyamidate. According to the liquid crystal alignment agent described in Patent Document 1, Patent Document 1 describes that the fine irregularities generated on the film surface of the liquid crystal alignment film are reduced, and the liquid crystal alignment properties and electrical characteristics of the liquid crystal display element are improved.

[Prior Art Literature] [Patent Literature] [Patent Literature 1] International Publication No. 2011/115078

[Problems to be Solved by the Invention]

In recent years, large-screen and high-definition liquid crystal televisions have become the main body. In addition, the popularization of small display terminals such as smart phones and tablet PCs has further increased the demand for high-definition liquid crystal panels. In addition, with the recent multi-purpose use of liquid crystal display elements, liquid crystal display elements are expected to be used in more severe conditions. Therefore, it is desirable that the liquid crystal display element appropriately exhibits various characteristics required in a well-balanced manner.

An object of the present invention is to provide a liquid crystal alignment agent capable of obtaining a liquid crystal display element capable of appropriately exhibiting various characteristics in a well-balanced manner. [Technical means to solve the problem]

The present inventors have actively studied in order to achieve the problems of the prior art as described above, and have found that the problems can be solved by introducing a functional functional group into the carboxyl portion of the amidine structure. Specifically, the following liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element are provided.

An aspect of the present disclosure is to provide a liquid crystal alignment agent containing a polymer (P) having a partial structure represented by the following formula (1).

[Chemical 1] (In formula (1), R ¹ is a tetravalent organic group, and R ² is a divalent organic group; X ¹ and X ² are each independently a hydroxyl group or a monovalent organic group having 1 to 40 carbon atoms; wherein X ¹ and At least one of X ² is a monovalent organic group having an aromatic amine structure, a heterocyclic group, and a polymerizable group selected from two or more aromatic rings directly bonded to a nitrogen atom. And light rearranged groups)

In addition, another aspect is to provide a liquid crystal alignment film formed using the liquid crystal alignment agent. In addition, a liquid crystal display element including the liquid crystal alignment film is provided. [Effect of the invention]

When at least a part of the polymer component of the liquid crystal alignment agent contains a polymer (P) having a specific partial structure, a liquid crystal display element capable of expressing various characteristics in a well-balanced manner can be obtained.

Hereinafter, the components blended in the liquid crystal alignment agent of the present disclosure, and other components arbitrarily blended as necessary will be described.

<Polymer (P)> The liquid crystal alignment agent of the present disclosure contains a polymer (P) having a partial structure represented by the following formula (1). [Chemical 2] (In formula (1), R ¹ is a tetravalent organic group, and R ² is a divalent organic group; X ¹ and X ² are each independently a hydroxyl group or a monovalent organic group having 1 to 40 carbon atoms; wherein X ¹ and At least one of X ² is a monovalent organic group having an aromatic amine structure selected from two or more aromatic rings directly bonded to a nitrogen atom, a heterocyclic group, a polymerizable group, and a light rearrangement group. One of the groups)

Examples of the monovalent organic group having 1 to 40 carbon atoms in X ¹ and X ² in the formula (1) include a monovalent hydrocarbon group having 1 to 40 carbon atoms; S-, -CO-, -COO-, -COS-, -NR3-, -CO-NR ^3- , -Si (R ³ ) _2- (wherein R ³ is a hydrogen atom or a carbon number of 1 to 12 Monovalent radicals substituted with -N = N-, -SO _2- , etc .; at least one of the hydrogen atoms of the monovalent radical and the hydrocarbon group bonded to the carbon atom is a halogen atom (fluorine atom , Chlorine, bromine, iodine, etc.), hydroxyl, alkoxy, nitro, amino, mercapto, nitroso, alkylsilyl, alkoxysilyl, silanol, sulfino group), a monovalent group substituted with a phosphine group, a carboxyl group, a cyano group, a sulfo group, a fluorenyl group, and the like; a monovalent group having a heterocyclic ring, and the like. Among them, at least one of X ¹ and X ² is a monovalent organic group having an aromatic amine structure selected from two or more aromatic rings directly bonded to a nitrogen atom (hereinafter also referred to as It is a functional functional group in a group consisting of a "specific aromatic amine structure"), a heterocyclic group, a polymerizable group, and a light rearrangeable group.

Herein, the "hydrocarbon group" in the present specification means a meaning including a chain hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. The "chain hydrocarbon group" refers to a straight-chain hydrocarbon group and a branched hydrocarbon group which are not composed of a cyclic structure in the main chain but are composed of only a chain structure. Among them, it may be saturated or unsaturated. The "alicyclic hydrocarbon group" refers to a hydrocarbon group containing only an alicyclic hydrocarbon structure as a ring structure and not containing an aromatic ring structure. However, it does not necessarily need to consist only of the structure of an alicyclic hydrocarbon, and also includes the hydrocarbon group which has a chain structure in a part. The "aromatic hydrocarbon group" means a hydrocarbon group containing an aromatic ring structure as a ring structure. However, it does not necessarily need to consist only of an aromatic ring structure, and may include a chain structure or an alicyclic hydrocarbon structure in part.

The polymer (P) can be synthesized by appropriately combining ordinary methods of organic chemistry. As an example of the synthesis method, for example, a method can be mentioned in which a tetracarboxylic dianhydride is reacted with the compound (E) having the functional functional group to synthesize a tetracarboxylic diester having the functional functional group. Then, the obtained tetracarboxylic acid diester is reacted with a diamine. In addition, the "tetracarboxylic acid diester" in this specification means the compound which esterified two of the four carboxyl groups which a tetracarboxylic acid has. The "tetracarboxylic acid diester dihalide" refers to a compound in which two of the four carboxyl groups of a tetracarboxylic acid are esterified, and the remaining two are halogenated.

[Tetracarboxylic dianhydride] Examples of the tetracarboxylic dianhydride used in the synthesis of the polymer (P) include aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, and aromatic tetracarboxylic dianhydride. . As specific examples of these tetracarboxylic dianhydrides, examples of the aliphatic tetracarboxylic dianhydride include butanetetracarboxylic dianhydride, and the like; and examples of the alicyclic tetracarboxylic dianhydride include 1,2,3,4. -Cyclobutane tetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 5- (2,5-dioxotetrahydrofuran-3-yl) -3a, 4,5,9b- Tetrahydronaphtho [1,2-c] furan-1,3-dione, 5- (2,5-dioxotetrahydrofuran-3-yl) -8-methyl-3a, 4,5,9b- Tetrahydronaphtho [1,2-c] furan-1,3-dione, 3-oxabicyclo [3.2.1] octane-2,4-dione-6-spiro-3 '-(tetrahydrofuran -2 ', 5'-dione), 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 3 , 5,6-tricarboxy-2-carboxymethylnorbornane-2: 3,5: 6-dianhydride, bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic acid 2: 4,6: 8-dianhydride, bicyclo [2.2.1] heptane-2,3,5,6-tetracarboxylic acid 2: 3,5: 6-dianhydride, 4,9-dioxatricyclo [ 5.3.1.02,6] Undecane-3,5,8,10-tetraketone, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, bicyclo [2.2.2] oct-7-ene- 2,3,5,6-tetracarboxylic dianhydride, ethylenediaminetetraacetic dianhydride, cyclopentanetetracarboxylic dianhydride, etc .;

Examples of the aromatic tetracarboxylic dianhydride include pyromellitic dianhydride, ethylene glycol bis (trimellitic anhydride ester), 1,3-propanediol bis (trimellitic anhydride), and the like; Tetracarboxylic dianhydride described in Japanese Patent Laid-Open No. 2010-97188 was used. The tetracarboxylic dianhydride used in the synthesis of the polymer (P) may be used alone or in combination of two or more kinds. In addition, R ¹ in the formula (1) is a tetravalent group derived from a tetracarboxylic dianhydride, that is, a residue obtained by removing two acid anhydride groups from the tetracarboxylic dianhydride.

Among these compounds, the tetracarboxylic dianhydride preferably contains a compound selected from the group consisting of bicyclic [2.2.1] heptane-2,3,5,6-tetracarboxylic acid 2: 3,5: 6-dianhydride, 1,2,3 , 4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 5- (2,5-dioxotetrahydrofuran-3-yl) -3a, 4,5, 9b-tetrahydronaphtho [1,2-c] furan-1,3-dione, 5- (2,5-dioxotetrahydrofuran-3-yl) -8-methyl-3a, 4,5, 9b-tetrahydronaphtho [1,2-c] furan-1,3-dione, bicyclo [3.3.0] octane-2,4,6,8-tetracarboxylic acid 2: 4,6: 8- At least one compound in the group consisting of dianhydride, cyclohexanetetracarboxylic dianhydride, and pyromellitic dianhydride. The amount of these preferred compounds (the total amount when two or more are used) is preferably 5 mol% or more with respect to the total amount of the tetracarboxylic dianhydride used in the synthesis of the polymer (P). It is more preferably 10 mol% or more, and even more preferably 20 mol% or more.

[Compound (E)] (Compound having specific aromatic amine structure) When compound (E) is a compound having specific aromatic amine structure (hereinafter also referred to as "compound (E-1)"), specific aromatic Examples of the aromatic ring directly bonded to a nitrogen atom in the family amine structure include a benzene ring, a naphthalene ring, and an anthracene ring. A benzene ring is preferred. Preferred specific examples of the specific aromatic amine structure include, for example, a group represented by the following formula (2-1), and a group represented by the following formula (2-2). [Chemical 3] (In formulas (2-1) and (2-2), R ⁵ is a hydrogen atom or a monovalent hydrocarbon group; R ⁶ and R ⁷ are each independently a monovalent substituent; d is an integer of 0 to 4, e and f are each independently an integer of 0 to 5; "*" represents a bonding bond)

Examples of the monovalent hydrocarbon group of R ⁵ in the formula (2-1) include a linear or branched alkyl group such as methyl, ethyl, propyl, butyl, pentyl, and hexyl, cyclohexyl, Phenyl, methylphenyl, etc. It is preferable that R ⁵ is hydrogen in terms of a high improvement effect of the afterimage characteristic of the liquid crystal display element (especially the afterimage characteristic called “DC afterimage” caused by the residual charge accumulated by the application of a DC voltage). Atom, methyl or phenyl, more preferably a hydrogen atom. Examples of the monovalent substituents of R ⁶ and R ⁷ include a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom, etc.), an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, Cycloalkyl with 3 to 20 carbons, aryl (phenyl, tolyl, etc.) with 5 to 20 carbons, nitro, hydroxyl, amino, mercapto, nitroso, alkylsilyl, alkoxysilyl , Silanol, sulfinate, phosphine, carboxyl, cyano, sulfo, fluorenyl and the like. d, e, and f are preferably 0 or 1.

Examples of the compound (E-1) include compounds represented by the following formula (3-1). [Chemical 4] (In formula (3-1), A ¹ is a group represented by the formula (2-1) or a group represented by the formula (2-2), and R ¹¹ is a single bond or a divalent hydrocarbon group)

Examples of the divalent hydrocarbon group of R ¹¹ in the formula (3-1) include a chain hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. Specific examples of these hydrocarbon groups include, for example, divalent chain hydrocarbon groups: methylene, ethylidene, propanediyl, butanediyl, glutaryl, hexamethylenediyl, heptylyl, octyldiyl, nonyl Radicals, decanediyl radicals, etc., these hydrocarbon radicals may be linear or branched. Examples of the divalent alicyclic hydrocarbon group of R ¹¹ include cyclohexyl, -R ^c- (CH ₂ ) _n- (where R ^c is cyclohexyl, and n is an integer of 1 to 5). Examples of the aromatic hydrocarbon group include phenylene, phenylene, -Ph- (CH ₂ ) _n- (where Ph is phenylene and n is an integer of 1 to 5).

Specific examples of the compound represented by the formula (3-1) include compounds represented by the following formulae (3-1-1) to (3-1-5), respectively. The compound (E-1) may be used alone or in combination of two or more. [Chemical 5] When the compound (E-1) is used, a polymer (P) having a specific aromatic amine structure in at least one of X1 and X2 in the formula (1) can be obtained. A liquid crystal alignment agent containing such a polymer (P) is preferable in terms of obtaining a liquid crystal display element having a small amount of residual DC and excellent electrical characteristics and reliability.

(Compound having a heterocyclic group) When the compound (E) is a compound having a heterocyclic group (hereinafter also referred to as "compound (E-2)"), the effect of improving the reliability of the liquid crystal display element is high. In this respect, the heterocyclic group is preferably a nitrogen-containing heterocyclic group, and examples thereof include: pyrrole, imidazole, pyrazole, triazole, pyridine, pyrimidine, pyridazine, pyrazine, indole, benzimidazole, purine, Quinoline, isoquinoline, naphthyridine, quinoxaline, phthalazine, triazine, thiazole, isothiazole, benzothiazole, 5,6,7,8-tetrahydroquinoline, pyridine, pyrazine, pyrrolidine N-valent group obtained by removing n hydrogen atoms from a nitrogen-containing heterocyclic ring such as hexamethyleneimine, decahydroquinoline, and the like. Among these, the heterocyclic ring having a heterocyclic group is preferably pyrrole, imidazole, pyrazole, pyridine, pyrimidine, pyridazine, triazine, triazole, pyrazine, or benzimidazole. The heterocyclic group may be a group having a substituent introduced into a ring portion. Examples of the substituent include halogen atoms such as fluorine atom, chlorine atom, and iodine atom; alkyl groups such as methyl, ethyl, and propyl; alkoxy groups such as methoxy, ethoxy, and propoxy; cyclohexyl and the like Cycloalkyl; aryl such as phenyl, tolyl, etc.

Examples of the compound (E-2) include compounds represented by the following formula (3-2). [Chemical 6] (In formula (3-2), A ² is a nitrogen-containing heterocyclic group, and R ¹² is a single bond or a divalent hydrocarbon group)

In the formula (3-2), the description of the divalent hydrocarbon group of R ¹² can be applied to the description of R ¹¹ of the formula (3-1). Specific examples of the compound represented by the formula (3-2) include compounds represented by the following formulae (3-2-1) to (3-2-22). The compound (E-2) may be used alone or in combination of two or more.

[Chemical 7] [Chemical 8] When the compound (E-2) is used, a polymer (P) having a heterocyclic group in at least one of X ¹ and X ² in the formula (1) can be obtained. A liquid crystal alignment agent containing such a polymer (P) is preferable in terms of obtaining a liquid crystal display element having good reliability and electrical characteristics.

(Compound Having a Polymerizable Group) When the compound (E) is a compound having a polymerizable group (hereinafter also referred to as a "compound (E-3)"), examples of the polymerizable group include polymerization initiated by light or heat. Group. Examples of the polymerizable group include a group having a polymerizable unsaturated bond. Specific examples of these groups include (meth) acrylfluorenyloxy, styryl, (meth) acrylfluorenylamino, and ethylene. An oxy group (CH ₂ = CH-O-), the following formula (p-1) and formula (p-2) (In the formula (p-1), X ⁵ is an oxygen atom or -NH-; "*" represents a bonding bond)

Represented groups, etc. The (meth) acrylfluorenyloxy group has a meaning including "acrylfluorenyloxy" and "methacrylfluorenyloxy". The (meth) acrylamido group has a meaning including "acrylamido" and "methacrylamido". Among these, in terms of high reactivity to light or heat, the polymerizable group is preferably a (meth) acrylfluorenyloxy group.

Examples of the compound (E-3) include compounds represented by the following formula (3-3). [Chemical 10] (In formula (3-3), A ³ is a polymerizable group, and R ¹³ is a single bond or a divalent hydrocarbon group)

In the formula (3-3), the description of the divalent hydrocarbon group of R ¹³ can be applied to the description of R ¹¹ in the formula (3-1). Specific examples of the compound represented by the formula (3-3) include, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 2-hydroxypropyl (meth) acrylate. Hydroxybutyl ester, hydroxyethyl (meth) acrylamide, 2-vinyloxyethanol, 2- (4-vinylbenzyloxy) ethanol, N- (hydroxymethyl) cis-butenedifluorene Amines, N-hydroxycis-butene diamidine, and the like. The compound (E-3) may be used alone or in combination of two or more. When the compound (E-3) is used, a polymer (P) having a polymerizable group in at least one of X ¹ and X ² in the formula (1) can be obtained. With the liquid crystal alignment agent containing such a polymer (P), it is possible to obtain a liquid crystal display element having a good pretilt angle characteristic when the alignment property is imparted by light irradiation, and a liquid crystal display element having good electrical characteristics and reliability. Words are preferred.

(Compound Having Light Rearrangement Group) Examples of the compound (E) include compounds having a light rearrangement group (hereinafter also referred to as "compound (E-4)"). The photorearrangement group possessed by the compound (E-4) is a functional group having a structure that causes a rearrangement reaction by light irradiation, and examples thereof include a structure represented by the following formula (p-3) (hereinafter also referred to as Are "aromatic ester-containing structures"). [Chemical 11] (In formula (p-3), X ³ is a sulfur atom, an oxygen atom, or -NH-; "*" represents a bonding bond; wherein at least one of the two "*" is bonded to an aromatic ring)

Examples of the aromatic ring bonded by "*" in the formula (p-3) include a benzene ring, a naphthalene ring, and an anthracene ring. At least one of the two "*" may be bonded to the aromatic ring, but from the viewpoint of photoresponse, it is preferable that the two "*" are respectively bonded to the aromatic ring.

The compound (E-4) having a photorearrangement group is represented by the following formula (3-4), for example. [Chemical 12] (In formula (3-4), A ⁴ is a light rearrangement group, and R ¹⁴ is a single bond or a divalent hydrocarbon group)

In the formula (3-4), the description of the divalent hydrocarbon group of R ¹⁴ can be applied to the description of R ¹¹ in the formula (3-1). Specific examples of the compound represented by the formula (3-4) include compounds represented by the following formulae (3-4-1) to (3-4-13). The compound (E-4) may be used alone or in combination of two or more. [Chemical 13] When the compound (E-4) is used, a polymer (P) having a photorearrangeable group on at least one of X ¹ and X ² in the formula (1) can be obtained. A liquid crystal alignment agent containing such a polymer (P) is preferable in terms of obtaining a liquid crystal display element with few AC afterimages, good electrical characteristics, and reliability.

(Reaction of tetracarboxylic dianhydride with compound (E)) The reaction of tetracarboxylic dianhydride with compound (E) may be performed in an organic solvent, if necessary. The organic solvent used is not particularly limited as long as it is inert to tetracarboxylic dianhydride and compound (E), and examples thereof include ketones such as acetone and methyl ethyl ketone; hydrocarbons such as hexane, heptane, and toluene; Halogen-based hydrocarbons such as chloroform and 1,2-dichloroethane; ethers such as tetrahydrofuran, diethyl ether and 1,4-dioxane; and nitrile compounds such as acetonitrile and propionitrile. These organic solvents may be used singly or in combination of two or more. The ratio of the compound (E) to 1 mol of the tetracarboxylic dianhydride is usually 2 to 100 mol, and preferably 2 to 40 mol. The reaction temperature at this time can be appropriately set depending on the kind of the compound (E) to be used, and is preferably -20 ° C to 150 ° C, and more preferably 0 ° C to 100 ° C. The reaction time is preferably from 0.1 to 24 hours, and more preferably from 0.5 to 12 hours. After the reaction, reprecipitation may be performed as necessary. Then, the obtained precipitate is washed and dried as necessary, thereby obtaining a target tetracarboxylic acid diester.

(Diamine) Examples of the diamine used in the reaction (polycondensation) with a tetracarboxylic acid diester include an aliphatic diamine, an alicyclic diamine, an aromatic diamine, and a diaminoorganosiloxane. As specific examples of these diamines, examples of the aliphatic diamine include m-xylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, and hexamethylenediamine. , 1,3-bis (aminomethyl) cyclohexane, etc .; Examples of the alicyclic diamine include: 1,4-diaminocyclohexane, 4,4'-methylenebis (cyclohexylamine), etc. ;

Examples of the aromatic diamine include dodecyloxydiaminobenzene, tetradecyloxydiaminobenzene, pentadecyloxydiaminobenzene, cetyloxydiaminobenzene, and octadecyloxydiamine. Aminobenzene, cholesteroxydiaminobenzene, cholestoxydiaminobenzene, cholesteryl diaminobenzoate, cholesteryl diaminobenzoate, lanosteryl diaminobenzoate , 3,6-bis (4-aminobenzyloxy) cholestane, 3,6-bis (4-aminophenoxy) cholestane, 1,1-bis (4-((aminobenzene (Methyl) methyl) phenyl) -4-butylcyclohexane, 1,1-bis (4-((aminophenyl) methyl) phenyl) -4-heptylcyclohexane, 1,1- Bis (4-((aminophenoxy) methyl) phenyl) -4-heptylcyclohexane, 1,1-bis (4-((aminophenyl) methyl) phenyl) -4- ( 4-heptylcyclohexyl) cyclohexane, N- (2,4-diaminophenyl) -4- (4-heptylcyclohexyl) benzamide, the following formula (D-1) [Chem. 14 ] (In formula (D-1), X ^I and X ^II are each independently a single bond, -O-, -COO-, or -OCO-, R ^I is an alkanediyl group having 1 to 3 carbon atoms, and R ^II is a single Bond or alkanediyl having 1 to 3 carbon atoms, a is 0 or 1, b is an integer of 0 to 2, c is an integer of 1 to 20, and d is 0 or 1, wherein a and b do not become 0 at the same time )

Compounds such as diamines containing alignment groups; 4,4'-diaminodiphenylamine, N, N-bis (4-aminophenyl) methylamine, N- (3,5-diamino Phenyl) aniline, N, N'-bis (4-aminophenyl) -benzidine, N, N'-bis (4-aminophenyl) -N, N'-dimethylbenzidine, the following formula (D-1)

Diamines having specific aromatic amine structures such as the compounds represented; 2,6-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminoacridine, 3,6-diaminooxazole, N -Methyl-3,6-diaminooxazole, 1,4-bis- (4-aminophenyl) -pyrazine, and the following formulae (d-2) to (d-5) Heterocyclic group-containing diamines such as the compounds represented by each; and the following formula (d-6) (In formula (d-6), R ⁸ is a hydrogen atom or a methyl group) a polymerizable group-containing diamine such as a compound represented by 4-aminophenyl-4'-aminobenzoate, 3,3 '-Dimethyl-4-aminophenyl-4'-aminobenzoate,3-methyl-4-aminophenyl-4'-aminobenzoate, and the following formulae (d-7) to ( d-14)

Photoreorderable diamines such as the compounds shown respectively; p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylamine, 4,4'- Diaminodiphenyl sulfide, 4,4'-diaminoazobenzene, 1,5-bis (4-aminophenoxy) pentane, 1,7-bis (4-aminophenoxy) heptane , Bis [2- (4-aminophenyl) ethyl] adipic acid, 1,5-diaminonaphthalene, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2 ' -Bis (trifluoromethyl) -4,4'-diaminobiphenyl, 4,4'-diaminodiphenyl ether, 2,2-bis [4- (4-aminophenoxy) phenyl] Propane, 9,9-bis (4-aminophenyl) fluorene, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl ) Hexafluoropropane, 4,4 '-(p-phenylene diisopropylidene) bisaniline, 1,4-bis (4-aminophenoxy) benzene, 4,4'-bis (4-aminobenzene (Oxy) biphenyl, 3,5-diaminobenzoic acid, and other diamines; examples of diaminoorganosiloxanes include 1,3-bis (3-aminopropyl) -tetramethyldisilazane Other than that, diamines described in Japanese Patent Laid-Open No. 2010-97188 can be used.

The divalent group represented by "-X ^I- (R ^I -X ^II ) _d- " in the formula (D-1) is preferably an alkyldiyl group having 1 to 3 carbon atoms, * -O-, *- COO- or * -OC ₂ H ₄ -O- (where the bond with "*" is bonded to diaminophenyl). Examples of the group "-C _c H _{2c + 1} " include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, deca Trialkyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, and the like are preferably linear. The two amino groups in the diaminophenyl group are preferably located at the 2,4-position or the 3,5-position with respect to the other groups.

Specific examples of the compound represented by the formula (D-1) include compounds represented by the following formulae (D-1-1) to (D-1-4). [Chemical 19] The diamine used in the reaction may be used alone or in combination of two or more of them.

When applied to a liquid crystal alignment agent for a TN-type, STN-type, or vertical alignment type liquid crystal display element, it is preferable to use a diamine containing an alignment group as at least the diamine used in the synthesis of the polymer (P). portion. Examples of the alignment group possessed by the alignment group-containing diamine include an alkyl group having 4 to 20 carbon atoms, a fluoroalkyl group having 4 to 20 carbon atoms, an alkoxy group having 4 to 20 carbon atoms, and 17 to 17 carbon atoms. 51 has a steroid skeleton, a group having a polycyclic structure, and the like. When a diamine containing an alignment group is used, it is preferable that the use ratio of the diamine containing an alignment group to the total diamine used in the synthesis is set to 3 mol% or more, more preferably 5 mol% to 70 mol%.

R ² in the formula (1) is a divalent group derived from a diamine, that is, a residue obtained by removing two primary amino groups from the diamine. When a diamine having the functional functional group is used for at least a part of the diamine used in the synthesis of the polymer (P), X ¹ and X ² in the formula (1) may be used. The functional functional group is introduced into at least one of R ² and R ² . In this case, it is preferable that the number of the functional functional groups per one polymer can be increased, and various characteristics of the functional functional groups can be sufficiently expressed. When using the diamine which has the said functional functional group, it is preferable that the usage ratio of the said diamine which has the said functional functional group is 5 mol% or more with respect to all the diamine used for synthesis. It is more preferably 10 mol% or more.

When a liquid crystal alignment ability is imparted to a coating film formed of a liquid crystal alignment agent by a photo-alignment method, at least a part of the tetracarboxylic dianhydride and diamine used in the reaction may be a compound having a photo-alignment structure. As the photo-alignment structure, a group that exhibits photo-alignment by photoisomerization, photodimerization, photodecomposition, or the like can be used. Specific examples include azo-containing groups containing an azo compound or a derivative thereof as a basic skeleton, cinnamic acid-containing groups containing cinnamic acid or a derivative thereof as a basic skeleton, and chalcone or a derivative thereof. Chalcone-containing group as a basic skeleton, benzophenone-containing group as a basic skeleton, coumarin-containing group as a basic skeleton Group, a cyclobutane-containing structure containing cyclobutane or a derivative thereof as a basic skeleton, and a bicyclic [2.2.2] octene containing bicyclic [2.2.2] octene or a derivative thereof as a basic skeleton Structure, aromatic ester-containing structure containing a partial structure represented by the formula (p-3) as a basic skeleton, and the like. In the case of using a monomer having a photo-alignment structure, from the viewpoint of photoreactivity, the use ratio of the monomer is preferably set to 20 moles relative to the total amount of monomers used in polymer synthesis. The ear% is more than or equal to 30 mole% and more preferably 80 mole%.

(Reaction of Tetracarboxylic Diester and Diamine) The reaction of the tetracarboxylic diester and diamine is preferably performed in an organic solvent in the presence of a dehydration catalyst and a base. The use ratio of the tetracarboxylic acid diester and diamine supplied to the reaction is preferably 1 equivalent to the amino group of the diamine, and the carboxyl group of the tetracarboxylic diester is a ratio of 0.2 to 2 equivalents, and more preferably 0.3 to 1.2 Equivalent ratio. In the reaction of a tetracarboxylic acid diester and a diamine, at least one compound selected from the group consisting of a tetracarboxylic acid dianhydride and a tetracarboxylic acid diester having no functional functional group may be used in combination. In this case, with respect to the total of the tetracarboxylic diester and the tetracarboxylic dianhydride used in the synthesis of the polymer (P), the use of the tetracarboxylic dianhydride and the tetracarboxylic diester having no functional functional group is used. The ratio (the total amount when two or more are used) is preferably 50 mol% or less, more preferably 40 mol% or less, and particularly preferably 30 mol% or less.

Examples of the organic solvent used in the reaction include aprotic polar solvents, phenol-based solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons, and hydrocarbons. Among these organic solvents, one or more selected from the group consisting of an aprotic polar solvent and a phenol-based solvent (organic solvent of the first group), or an organic solvent selected from the first group is preferably used. A mixture of one or more compounds selected from the group consisting of alcohols, ketones, esters, ethers, halogenated hydrocarbons, and hydrocarbons (organic solvents of the second group). In the latter case, the use ratio of the organic solvent in the second group is preferably 50% by weight or less, and more preferably 40% by weight, with respect to the total amount of the organic solvent in the first group and the organic solvent in the second group. Hereinafter, it is particularly preferably 30% by weight or less.

Particularly preferred organic solvents are preferably those selected from the group consisting of N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethylsulfinium, and γ-butane. One or more of the group consisting of lactone, tetramethylurea, hexamethylphosphonium triamine, m-cresol, xylenol and halogenated phenol are used as a solvent, or these organic solvents are used within the range of the ratio A mixture of more than one with other organic solvents. It is preferable that the usage-amount (a) of an organic solvent is an amount which becomes 0.1 weight%-50 weight% with respect to the total amount (a + b) of a reaction solution, and the total amount (b) of the monomer used for a reaction.

Examples of the dehydration catalyst used in the reaction include 4- (4,6-dimethoxy-1,3,5-triazin-2-yl) -4-methylmorpholinium halide, carbonylimidazole, and diamine. Cyclohexylcarbodiimide, phosphorus-based condensing agents, and the like. The use ratio of these dehydration catalysts is preferably 2 mol to 3 mol, and more preferably 2 mol to 2.5 mol relative to 1 mol of the tetracarboxylic acid diester. As the base, for example, a tertiary amine such as pyridine or triethylamine can be preferably used. The use ratio of the base with respect to 1 mole of the diamine is preferably 2 to 4 moles, and more preferably 2 to 3 moles. Further, for the purpose of promoting the reaction, the reaction may be performed in the presence of a Lewis acid. Examples of the Lewis acid include lithium halides such as lithium chloride. The reaction temperature is preferably -20 ° C to 150 ° C, and more preferably 0 ° C to 100 ° C. The reaction time is preferably from 0.1 to 24 hours, and more preferably from 0.5 to 12 hours.

In the manner described above, a reaction solution obtained by dissolving the polymer (P) was obtained. The reaction solution can be directly provided to the preparation of the liquid crystal alignment agent, or the polymer (P) contained in the reaction solution can be separated and then provided to the preparation of the liquid crystal alignment agent, or the separated polymer (P) can be purified. It is then provided to the preparation of the liquid crystal alignment agent. Isolation and purification of the polymer (P) can be performed according to a known method.

In addition, in addition to a method of reacting a tetracarboxylic acid diester with a diamine, the polymer (P) can also be obtained by the following method, for example: [A] a method of reacting a polyamic acid with a compound (E) [B] A method of reacting a tetracarboxylic diester dihalide having the functional functional group with a diamine, and the like. The polymer (P) may have only a sulfonate structure, or may be a partially esterified product in which a glutamic acid structure and a glutamic acid ester structure coexist.

Here, in the case of the method [A], the compound (E) used in the reaction with polyamic acid is not particularly limited as long as it has the functional functional group, and examples thereof include the compound (E -1) to the compound (E-4), or an epoxy compound, a thiol compound, an amine compound, and the like having the functional functional group. When the polyamic acid is reacted with the compound (E), other esterifying agents having no functional functional group may be used together with the compound (E) as necessary. Examples of other esterifying agents include: alcohols such as methanol and ethanol; phenols such as phenol and cresol; N, N-dimethylformamide diethyl acetal, N, N-diethylformamide Acetal compounds such as ethyl acetal and the like. In the case of using other esterifying agents, the use ratio of the other esterifying agents is preferably 30 mol% or less, and more preferably 20 mol relative to the total amount of the esterifying agents used in the reaction. %the following.

The reaction between the polyamic acid and the compound (E) is preferably performed in the presence of an organic solvent. At this time, the use ratio of the compound (E) is preferably 0.002 to 10 mol, and more preferably 0.02 to 6 mol with respect to 1 mol of the repeating unit of the polyamic acid. As the organic solvent to be used, the description of the organic solvent used in the reaction between the tetracarboxylic acid diester and the diamine can be applied. The amount of the organic solvent used is preferably an amount of 0.1 to 50% by weight of the polyamic acid relative to the total amount of the reaction solution. The reaction temperature is preferably -20 ° C to 200 ° C, and more preferably 0 ° C to 120 ° C. The reaction time is preferably from 0.1 to 24 hours, and more preferably from 0.5 to 12 hours.

The tetracarboxylic acid diester dihalide used in the method [B] can be obtained by reacting the tetracarboxylic acid diester obtained in the manner described above with an appropriate chlorinating agent such as thionyl chloride. The acid derivative used in the reaction with the diamine may be only a tetracarboxylic diester dihalide, or a tetracarboxylic dianhydride may be used in combination. Examples of the diamine used in the reaction include compounds exemplified as the diamine used in the reaction with a tetracarboxylic acid diester. The use ratio of the tetracarboxylic diester dihalide to the diamine provided for the polymer (P) synthesis reaction is preferably 1 equivalent to the amino group of the diamine, and the group of the tetracarboxylic diester dihalide "-COX (X is a halogen atom) is a ratio of 0.2 to 2 equivalents, and more preferably a ratio of 0.3 to 1.2 equivalents.

The reaction of the tetracarboxylic diester dihalide with the diamine is preferably performed in an organic solvent in the presence of a base. The reaction temperature at this time is preferably -30 ° C to 150 ° C, and more preferably -10 ° C to 100 ° C. The reaction time is preferably from 0.1 to 24 hours, and more preferably from 0.5 to 12 hours. As the organic solvent used in the reaction, a description of an organic solvent that can be used in the reaction between a tetracarboxylic acid diester and a diamine can be applied. The used amount of the organic solvent is preferably an amount in which the total amount of the tetracarboxylic diester dihalide and the diamine is 0.1 to 50% by weight based on the total amount of the reaction solution. Examples of the base used in the reaction include tertiary amines such as pyridine and triethylamine; alkali metals such as sodium hydride, potassium hydride, sodium hydroxide, potassium hydroxide, sodium, and potassium; and the like. The use amount of the base is preferably 2 to 4 mol, and more preferably 2 to 3 mol, relative to 1 mol of the diamine.

The polymer (P) obtained as described above is preferably one having a solution viscosity of 20 mPa · s to 1,800 mPa · s when it is made into a solution having a concentration of 15% by weight, and more preferably 50 mPa · Solution viscosity from s to 1,500 mPa · s. In addition, the solution viscosity (mPa · s) of the polymer (P) is 15 when the polymer (P) is used as a good solvent (eg, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.). A weight% polymer solution was measured at 25 ° C. using an E-type viscometer.

The polymer (P) has a polystyrene-equivalent weight average molecular weight (Mw) measured by Gel Permeation Chromatography (GPC), preferably 1,000 to 500,000, and more preferably 2,000 to 300,000. The molecular weight distribution (Mw / Mn) represented by the ratio of Mw to the polystyrene-equivalent number average molecular weight (Mn) measured by GPC is preferably 7 or less, and more preferably 5 or less. By being in the said molecular weight range, favorable orientation and stability of a liquid crystal display element can be ensured.

<Polymer (Q)> The liquid crystal alignment agent of the present disclosure may contain only the polymer (P) as a polymer component, or may contain the polymer (P) selected from the group consisting of polyamic acid and polyimide At least one polymer (Q) in the group. In addition, when a liquid crystal alignment agent containing a polymer (P) and a polymer (Q) is used to form a coating film on a substrate, the polymer (P) may be biased toward the coating film depending on the difference in surface energy. The outer layer, from which it is presumed to obtain the effect.

(Polyamidoacid) The polyamidoacid as the polymer (Q) can be obtained, for example, by reacting a tetracarboxylic dianhydride with a diamine. Examples of the tetracarboxylic dianhydride and diamine used in the reaction are examples of the tetracarboxylic dianhydride and diamine used in the synthesis of the polymer (P). The use ratio of the tetracarboxylic dianhydride and the diamine provided for the synthesis reaction of the polyamic acid is preferably 1 equivalent to the amino group of the diamine, and the acid anhydride group of the tetracarboxylic dianhydride becomes a ratio of 0.2 to 2 equivalents. The ratio is preferably 0.3 to 1.2 equivalents.

The synthesis reaction of the polyamic acid is preferably performed in an organic solvent. The reaction temperature at this time is preferably -20 ° C to 150 ° C, and more preferably 0 ° C to 100 ° C. The reaction time is preferably from 0.1 to 24 hours, and more preferably from 0.5 to 12 hours. Examples of the organic solvent used in the reaction include an organic solvent used in the reaction of a tetracarboxylic acid diester and a diamine. The reaction temperature is preferably -20 ° C to 150 ° C, and more preferably 0 ° C to 100 ° C. The reaction time is preferably from 0.1 to 24 hours, and more preferably from 0.5 to 12 hours.

In the manner as described above, a reaction solution obtained by dissolving polyamic acid was obtained. The reaction solution may be directly provided to the preparation of the liquid crystal alignment agent, or the polyamidic acid contained in the reaction solution may be separated and then provided to the preparation of the liquid crystal alignment agent, or the separated polyamidic acid may be purified and then Provided for preparation of liquid crystal alignment agent. In the case where the polyamidic acid is subjected to dehydration and ring closure to form a polyimide, the reaction solution may be directly provided to the dehydration ring-closure reaction, or the polyamidic acid contained in the reaction solution may be separated and then supplied to the The dehydration ring-closing reaction, or the isolated polyamidic acid may be purified and then provided to the dehydration ring-closing reaction. Isolation and purification of polyamic acid can be performed according to a known method. When a polyamic acid is contained as a polymer (Q), it is preferable from the point which can not only obtain the effect by compounding a polymer (P), but also can further improve printability.

(Polyimide) The polyimide as the polymer (Q) can be obtained, for example, by dehydrating and ring-closing the polyamidoacid synthesized in the manner described above, and then imidating.

The polyamidoimide may be a complete phosphonium imide obtained by dehydrating and ring-closing all the phosphoamidate structures of the polyphosphonic acid as a precursor thereof, or may be dehydrating and cyclizing only a part of the phosphoamidate structure. In addition, a part of the sulfonium imide compound in which the sulfonium acid structure and the sulfonium ring structure coexist. The polyimide used in the reaction is preferably 20% or more, more preferably 30% to 99%, and particularly preferably 40% to 99%. This fluorene imidization ratio is a total of the number of fluorene imine structures and the number of fluorene imine rings with respect to the total number of fluorene imine rings and the number of fluorene imine rings. Here, a part of the fluorene imine ring may be an isofluorene ring.

The dehydration ring closure of the polyamic acid is preferably performed by a method of heating the polyamic acid; or the polyamic acid is dissolved in an organic solvent, and a dehydrating agent and a dehydration ring closure catalyst are added to the solution. A method of heating is required. Among these, the method using the latter is preferable.

In the method of adding a dehydrating agent and a dehydration ring-closing catalyst to a solution of a polyamic acid, acid anhydrides, such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride, can be used as a dehydrating agent. The amount of the dehydrating agent to be used is preferably 0.01 to 20 mol relative to 1 mol of the fluoric acid structure of the polyamic acid. Examples of the dehydration ring-closing catalyst include tertiary amines such as pyridine, trimethylpyridine, dimethylpyridine, and triethylamine. The amount of the dehydration ring-closing catalyst used is preferably 0.01 mol to 10 mol relative to 1 mol of the dehydrating agent used. Examples of the organic solvent used in the dehydration ring-closing reaction include organic solvents exemplified as a compound used in the reaction of a tetracarboxylic acid diester and a diamine. The reaction temperature of the dehydration ring-closing reaction is preferably 0 ° C to 180 ° C, and more preferably 10 ° C to 150 ° C. The reaction time is preferably 1.0 to 120 hours, and more preferably 2.0 to 30 hours.

In this way, a reaction solution containing polyfluoreneimine was obtained. The reaction solution can be directly provided to the preparation of the liquid crystal alignment agent, or the dehydrating agent and the dehydration ring-closed catalyst can be removed from the reaction solution and then provided to the preparation of the liquid crystal alignment agent, or the polyfluorene imide can be separated and then provided to the liquid crystal alignment agent. Preparation of the agent, or the isolated polyfluorene imide may be purified and then provided to the preparation of the liquid crystal alignment agent. These purification operations can be performed according to a known method. When a polyfluorene imide is contained as a polymer (Q), it is preferable from the point which can not only obtain the effect by compounding a polymer (P), but also can improve electrical characteristics.

The polymer (Q) is preferably one having a solution viscosity of 20 mPa · s to 1,800 mPa · s when it is made into a solution having a concentration of 15% by weight, and more preferably 50 mPa · s to 1,500 mPa · s. Solution viscosity. In addition, the solution viscosity (mPa · s) of the polymer (Q) is 15 when the polymer (Q) is used as a good solvent (eg, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.). A weight% polymer solution was measured at 25 ° C. using an E-type viscometer.

The polystyrene-equivalent weight average molecular weight (Mw) of the polymer (Q) measured by GPC is preferably 1,000 to 500,000, and more preferably 2,000 to 300,000. The molecular weight distribution (Mw / Mn) represented by the ratio of Mw to the polystyrene-equivalent number average molecular weight (Mn) measured by GPC is preferably 7 or less, and more preferably 5 or less.

When the liquid crystal alignment agent of the present disclosure contains the polymer (Q), the content ratio of the polymer (P) is preferably appropriately set depending on the type of the functional functional group that the polymer (P) has. Specifically, when the polymer (P) has a specific aromatic amine structure or a heterocyclic group in at least one of X ¹ and X ² in the formula (1), the polymer (P) is preferred to the polymer The total of (P) and the polymer (Q) is 100 parts by weight, and the content ratio of the polymer (P) is set to 40 parts by weight or more. When the content ratio of the polymer (P) is less than 40 parts by weight, the reliability of the liquid crystal display element tends to deteriorate. It is more preferably 45 to 99 parts by weight, particularly preferably 50 to 97 parts by weight, and particularly preferably 60 to 95 parts by weight. When the polymer (P) has a polymerizable group in at least one of X ¹ and X ² in the formula (1), it is preferable from the viewpoint of imparting a moderately high pretilt angle to the coating film. The content ratio of the polymer (P) is 3 parts by weight or more with respect to 100 parts by weight of the total of the polymer (P) and the polymer (Q), and more preferably 5 to 95 parts by weight, especially It is preferably 10 to 90 parts by weight, and particularly preferably 15 to 85 parts by weight. When the polymer (P) has a light rearranging group in at least one of X ¹ and X ² in the formula (1), the afterimage characteristics of the liquid crystal display element (especially by From the viewpoint of the effect of improving afterimage characteristics called "AC afterimage" caused by AC voltage, it is preferred that the polymer (P) is added to the polymer (P) and the polymer (Q) in a total amount of 100 parts by weight. The content ratio of) is 3 parts by weight or more, more preferably 5 to 95 parts by weight, particularly preferably 10 to 90 parts by weight, and particularly preferably 15 to 85 parts by weight.

<Other Components> The liquid crystal alignment agent of the present disclosure may contain components (other components) other than the polymer (P) and the polymer (Q) as necessary. Examples of other components include polymers other than polymers (P) and (Q), compounds having at least one epoxy group in the molecule (hereinafter referred to as "epoxy-containing compounds"), and functional silane compounds Wait.

[Other polymers] The other polymers may be used for improving solution characteristics or electrical characteristics. Examples of the other polymers include polyamidates, polyorganosiloxanes, polyesters, polyamides, and fibers having a main skeleton that does not have the functional functional group in the carboxyl portion of the amino acid structure. Polymers, such as polyvinyl derivatives, polyacetals, polystyrene derivatives, poly (styrene-phenylcis butylene diimide) derivatives, poly (meth) acrylates, and the like. When other polymers are blended in the liquid crystal alignment agent, the blending ratio of the other polymers is preferably 50 parts by weight or less with respect to 100 parts by weight of the total polymer contained in the liquid crystal alignment agent. It is preferably 0.1 to 40 parts by weight, and particularly preferably 0.1 to 30 parts by weight.

[Epoxy-containing compound] The epoxy-containing compound can be used to improve the adhesiveness or electrical characteristics of the liquid crystal alignment film to the substrate surface. Examples of such epoxy group-containing compounds include the following compounds: ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl Ether, N, N, N ', N'-tetraglycidyl-m-xylylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ', N'-tetraglycidyl-4,4'-diaminodiphenylmethane, N, N-diglycidyl-aminomethylcyclohexane, ethyl glycidyl ether and the like. Other examples of the epoxy group-containing compound include an epoxy group-containing polyorganosiloxane described in International Publication No. 2009/096598. When an epoxy group-containing compound is blended in a liquid crystal alignment agent, the blending ratio of the epoxy group-containing compound is preferably set to 100 parts by weight based on a total of 100 parts by weight of a polymer contained in the liquid crystal alignment agent. 40 parts by weight or less, more preferably 0.1 to 30 parts by weight.

[Functional Silane Compound] The functional silane compound can be used for the purpose of improving the printability of a liquid crystal alignment agent. Examples of such a functional silane compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and N- (2-aminoethyl) -3-aminopropyltrimethoxysilane , N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxy Silane, 10-trimethoxysilyl-1,4,7-triazadecane, N-benzyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxy Silane, 3-glycidoxypropyltrimethoxysilane, etc. When the other functional silane compound is formulated in a liquid crystal alignment agent, the ratio of the other functional silane compound to the total weight of the polymer contained in the liquid crystal alignment agent is preferably 2 weight. Parts or less, more preferably 0.02 to 0.2 parts by weight.

In addition to the above-mentioned compounds, other components may include a compound or an antioxidant having at least one oxetanyl group in the molecule, a metal chelate compound, a hardening accelerator, a surfactant, a filler, a dispersant, Sensitizer and so on.

<Solvent> The liquid crystal alignment agent of the present disclosure is prepared as a liquid composition in which the polymer (P) and other components used as necessary are dispersed or dissolved in a suitable solvent.

Examples of the organic solvent used include N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N, N-dimethylformamide, and N, N-dimethylethyl Amine, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, Ethylene glycol methyl ether, ethylene glycol ether, ethylene glycol-n-propyl ether, ethylene glycol-isopropyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol Diethyl 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, diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, diisoamyl ether, ethylene carbonate, propylene carbonate, and the like. These organic solvents may be used alone or in combination of two or more.

The solid content concentration in the liquid crystal alignment agent (the ratio of the total weight of components other than the solvent of the liquid crystal alignment agent to the total weight of the liquid crystal alignment agent) may be appropriately selected in consideration of viscosity and volatility, and is preferably 1% by weight -10% by weight. That is, the liquid crystal alignment agent is applied to the surface of the substrate by a method described later, and it is preferable to perform heating to form a coating film as a liquid crystal alignment film or a coating film that becomes a liquid crystal alignment film. At this time, when the solid content concentration is less than 1% by weight, the film thickness of the coating film becomes too small, and it is difficult to obtain a good liquid crystal alignment film. On the other hand, when the solid content concentration exceeds 10% by weight, the film thickness of the coating film becomes too large, and it is difficult to obtain a good liquid crystal alignment film. In addition, the viscosity of the liquid crystal alignment agent tends to increase and the coatability tends to decrease.

A particularly preferred range of the solid content concentration varies depending on the method used when the liquid crystal alignment agent is applied to the substrate. For example, when the substrate is applied by a spinner method, the solid content concentration (the ratio of the total weight of all components other than the solvent in the liquid crystal alignment agent to the total weight of the liquid crystal alignment agent) is particularly preferably 1.5 weight. % To 4.5% by weight. When the printing method is used, it is particularly preferable to set the solid content concentration to a range of 3% to 9% by weight, and thereby set the solution viscosity to a range of 12 mPa · s to 50 mPa · s. In the case of using the inkjet method, it is particularly preferable to set the solid content concentration to a range of 1% to 5% by weight, and thereby set the solution viscosity to a range of 3 mPa · s to 15 mPa · s. The temperature when preparing the liquid crystal alignment agent is preferably 10 ° C to 50 ° C, and more preferably 20 ° C to 30 ° C.

<Liquid crystal display element> The liquid crystal display element of the present disclosure includes a liquid crystal alignment film formed using the liquid crystal alignment agent described above. The operation mode of the liquid crystal display element is not particularly limited. For example, it can be applied to TN type, STN type, and VA type (including Vertical Alignment-Multi-domain Vertical Alignment (VA-MVA)) type, vertical alignment. -Various alignment modes (Vertical Alignment-Patterned Vertical Alignment (VA-PVA) type, etc.), IPS type, FFS type, Optically Compensated Bend (OCB) type and other operating modes.

The liquid crystal display element can be manufactured, for example, by the following steps (1) to (3). Step (1) uses different substrates according to the required operation mode. Steps (2) and (3) are shared in each operation mode.

[Step (1): Formation of Coating Film] First, a liquid crystal alignment agent is coated on a substrate, and then the coating surface is heated to form a coating film on the substrate. (1-1) In the case of manufacturing, for example, a TN-type, STN-type, or VA-type liquid crystal display element, first, two substrates provided with a patterned transparent conductive film are used as a pair, preferably by an offset printing method, In a spin coating method, a roll coater method, or an inkjet printing method, a liquid crystal alignment agent is coated on each transparent conductive film forming surface of the substrate. For the substrate, for example, glass such as float glass and soda glass; plastics such as polyethylene terephthalate, polybutylene terephthalate, polyether, polycarbonate, and poly (alicyclic olefin) can be used. Transparent substrate. The transparent conductive film provided on one side of the substrate may be a NESA film (registered trademark of the American PPG Corporation) containing tin oxide (SnO ₂ ), or an indium oxide-tin oxide (In ₂ O ₃ -SnO ₂ ) Indium tin oxide (ITO) film, etc. In order to obtain a patterned transparent conductive film, for example, the following methods can be used: a method of forming a pattern by forming a transparent conductive film without a pattern, and then forming a pattern by photoetching; a method of forming a transparent conductive film using a mask having a desired pattern, etc. . When the liquid crystal alignment agent is applied, in order to improve the adhesion between the substrate surface and the transparent conductive film and the coating film, the surface on which the coating film is formed may be coated with a functional silane compound or a functional titanium compound in advance. Pre-processing.

After the liquid crystal alignment agent is applied, it is preferable to perform preheating (prebaking) for the purpose of preventing the applied liquid crystal alignment agent from sagging or the like. The pre-baking temperature is preferably 30 ° C to 200 ° C, more preferably 40 ° C to 150 ° C, and particularly preferably 40 ° C to 100 ° C. The pre-baking time is preferably 0.25 minutes to 10 minutes, and more preferably 0.5 minutes to 5 minutes. Then, in order to completely remove the solvent, and if necessary, perform a thermal sulfonimidization of the sulfamic acid structure present in the polymer, a sintering (post-baking) step is performed. The calcination temperature (post-baking temperature) at this time is preferably 80 ° C to 300 ° C, and more preferably 120 ° C to 250 ° C. The post-baking time is preferably 5 minutes to 200 minutes, and more preferably 10 minutes to 100 minutes. The film thickness of the film formed in this way is preferably 0.001 μm to 1 μm, and more preferably 0.005 μm to 0.5 μm.

(1-2) In the case of manufacturing an IPS-type or FFS-type liquid crystal display element, an electrode-forming surface of a substrate including an electrode patterned with a comb-shaped transparent conductive film or a metal film, and an electrode not provided A liquid crystal alignment agent is coated on one side of the opposite substrate, and then each coated surface is heated to form a coating film. The material, coating method, heating conditions after coating, the patterning method of the transparent conductive film or metal film, the substrate pretreatment, and the preferred film thickness and thickness of the coating film to be used. The description (1-1) is the same. As the metal film, for example, a film containing a metal such as chromium can be used.

In any of the cases (1-1) and (1-2), after the liquid crystal alignment agent is coated on the substrate, the organic solvent is removed to form a liquid crystal alignment film or a coating film that becomes a liquid crystal alignment film. At this time, by further heating after the formation of the coating film, the polyamidic acid, polyamidate, and polyimide prepared in the liquid crystal alignment agent may be subjected to a dehydration and ring-closing reaction to form a further perylene imine. Coating.

[Step (2): Alignment Capability Provisioning Process] When manufacturing a TN-type, STN-type, IPS-type, or FFS-type liquid crystal display element, a process of imparting liquid crystal alignment capability to the coating film formed in the step (1) is performed . As a result, the alignment ability of the liquid crystal molecules is imparted to the coating film to become a liquid crystal alignment film. Examples of the alignment ability imparting process include a rubbing process and a photo-alignment process. The rubbing process uses a roller wound with a cloth containing fibers such as nylon, rayon, and cotton to wipe the coating film in a certain direction; the photo-alignment. Processes radiation that irradiates the coating film with polarized or unpolarized light. On the other hand, in the case of manufacturing a VA-type liquid crystal display element, the coating film formed in the step (1) may be directly used as a liquid crystal alignment film, or an alignment ability imparting process may be performed on the coating film.

In the photo-alignment treatment, for example, ultraviolet rays and visible rays including light having a wavelength of 150 to 800 nm can be used as the radiation to be applied to the coating film. When the radiation is polarized light, it may be linearly polarized light or partially polarized light. In addition, when the radiation used is linearly polarized or partially polarized, the substrate surface may be irradiated from a vertical direction, or may be irradiated from an oblique direction, or these irradiations may be performed in combination. In the case where non-polarized radiation is irradiated, the direction of irradiation is set to an oblique direction. The light source used can be, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, an excimer laser, and the like. Ultraviolet rays in a preferred wavelength region can be obtained by a method in which a light source is used in combination with, for example, a filter, a diffraction grating, and the like. The radiation dose is preferably 100 J / m ² to 50,000 J / m ² , and more preferably 300 J / m ² to 20,000 J / m ² . In addition, in order to improve the reactivity, the coating film may be irradiated with light while being heated. The temperature during heating is usually 30 ° C to 250 ° C, preferably 40 ° C to 200 ° C, and more preferably 50 ° C to 150 ° C.

In addition, the following treatment may also be performed on the liquid crystal alignment film after the rubbing treatment, so that the liquid crystal alignment film has different liquid crystal alignment capabilities in each region: a part of the liquid crystal alignment film is irradiated with ultraviolet rays to make a part of the liquid crystal alignment film A process of changing the pretilt angle of the region; or a process of forming a resist film on a part of the surface of the liquid crystal alignment film, then performing a rubbing treatment in a direction different from the rubbing treatment just before, and then removing the resist film. In this case, the visual field characteristics of the obtained liquid crystal display element can be improved.

In the case of manufacturing a polymer sustained alignment (PSA) type liquid crystal display device, the following step (3) can be directly performed using the coating film formed in the step (1), but for the purpose of controlling the liquid crystal molecules The collapsing can be performed by a simple method for the purpose of alignment division, and can also be subjected to alignment processing such as weak friction processing. A liquid crystal alignment film suitable for a VA type liquid crystal display element can also be suitably used for a PSA type liquid crystal display element. When a coating film is formed using a liquid crystal alignment agent containing a polymerizable group-containing component, the following step (3) is directly performed using the coating film formed in (1).

[Step (3): Construction of liquid crystal cell] (3-1) Two substrates having the liquid crystal alignment film formed as described above are prepared, and liquid crystal is disposed between the two substrates disposed opposite to each other, thereby manufacturing a liquid crystal cell. In order to manufacture a liquid crystal cell, the following two methods are mentioned, for example. First, the first method is a conventionally known method. In this method, firstly, two substrates are arranged to face each other through a gap (cell gap) so that the liquid crystal alignment films face each other, and the peripheral portions of the two substrates are bonded together with a sealant. After filling the divided cell gap with liquid crystal, the injection hole is sealed to manufacture a liquid crystal cell. The second method is a method called a One Drop Fill (ODF) method. In this method, a predetermined portion of one of the two substrates on which the liquid crystal alignment film is formed is coated with a UV-curable sealant, for example, and liquid crystals are added dropwise to predetermined positions on the liquid crystal alignment film surface. Then, another substrate is bonded in a manner that the liquid crystal alignment film faces each other. Next, the liquid crystal is spread on the entire surface of the substrate, and then the entire surface of the substrate is irradiated with ultraviolet light to harden the sealant, thereby manufacturing a liquid crystal cell. In any case, it is desirable to eliminate the liquid crystal by heating the liquid crystal cell manufactured as described above and further heating the liquid crystal to a temperature at which the isotropic phase is obtained, and then slowly cooling to room temperature. Flow alignment during filling.

As the sealant, for example, an epoxy resin containing a hardener and alumina balls as a spacer can be used. Examples of the liquid crystal include nematic liquid crystals and dish liquid crystals. Among them, nematic liquid crystals are preferred. For example, Schiff base liquid crystals, azoxy liquid crystals, biphenyl liquid crystals, Phenylcyclohexane-based liquid crystal, ester-based liquid crystal, terphenyl-based liquid crystal, biphenylcyclohexane-based liquid crystal, pyrimidine-based liquid crystal, dioxane-based liquid crystal, bicyclooctane-based liquid crystal, cubane-based liquid crystal, etc. . In addition, these liquid crystals can also be used by adding the following substances: for example, cholesteric liquid crystals such as cholesteryl chloride, cholesteryl nonanoate, and cholesteryl carbonate ); Chiral agents sold under the trade names "C-15" and "CB-15" (Merck); p-decoxybenzylidene-p-amino-2-methylbutyl Ferroelectric liquid crystals such as cinnamate.

(3-2) In the case of manufacturing a PSA type liquid crystal display element, a liquid crystal cell is constructed in the same manner as in (3-1) above except that a photopolymerizable compound is injected or dropped together with the liquid crystal. Then, the liquid crystal cell is irradiated with light while a voltage is applied between the conductive films included in the pair of substrates. The voltage applied here may be, for example, 5 V to 50 V DC or AC. As the light to be irradiated, ultraviolet rays and visible rays including, for example, light having a wavelength of 150 to 800 nm can be used, and ultraviolet rays including light having a wavelength of 300 to 400 nm can be used. As a light source for irradiating light, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, an excimer laser, or the like can be used. The ultraviolet rays in the preferable wavelength region can be obtained by a method in which a light source is used in combination with, for example, a filter, a diffraction grating, and the like. The irradiation amount of light is preferably 1,000 J / m ² or more and less than 200,000 J / m ² , and more preferably 1,000 J / m ² to 100,000 J / m ² .

(3-3) In the case where a coating film is formed on a substrate using a liquid crystal alignment agent containing a polymer having a photopolymerizable group as the polymer (P), it may be passed through a pair of substrates by conducting electricity. A step of irradiating the liquid crystal cell with light under a voltage applied between the films to produce a liquid crystal display element. The conditions of the applied voltage or the applied light can be applied to the description of (3-2).

Next, a liquid crystal display element can be obtained by bonding a polarizing plate on the outer surface of a liquid crystal cell. Examples of the polarizing plate attached to the outer surface of the liquid crystal cell include a polarizing plate formed by sandwiching a polarizing film called an “H film” with a protective cellulose acetate film or a polarizing plate including the H film itself. The "H film" is a film formed by absorbing iodine while extending the orientation of polyvinyl alcohol.

The liquid crystal display element of the present disclosure can be effectively applied to a variety of devices, such as: clocks, portable game consoles, word processors, notebook personal computers, car navigation systems, camcorders, and personal digital assistants. PDA), digital cameras, mobile phones, smart phones, various monitors, LCD TVs, information displays and other display devices. [Example]

Hereinafter, the present invention will be described in more detail through examples, but the present invention is not limited to these examples.

In the following examples, the weight average molecular weight Mw of the polymer and the solution viscosity of the polymer solution were measured by the following methods. In addition, the compound represented by Formula X may be abbreviated as "compound X" below. [Polymer average molecular weight Mw] Mw is a polystyrene conversion value measured by GPC under the following conditions. Column: manufactured by Tosoh Co., Ltd., TSKgelGRCXLII Solvent: tetrahydrofuran Temperature: 40 ° C Pressure: 68 kgf / cm ² [Solution viscosity of polymer solution] The polymer was measured at 25 ° C using an E-type viscometer Solution viscosity (mPa · s) of the solution.

<Synthesis of Polymer [1]> [Synthesis Example 1-1: Synthesis of Polymer (A-1-1)] 100 mol parts of 1,2,3,4-ring as tetracarboxylic dianhydride Butane tetracarboxylic dianhydride and 200 mol parts of 4-hydroxydiphenylamine (the compound represented by the formula (3-1-1)) as compounds (E) were added to tetrahydrofuran and stirred. . The obtained precipitate was separated by filtration, washed with acetone, and then dried under reduced pressure, whereby the compound (AE-1-1) was obtained as a tetracarboxylic acid diester in powder form. Next, 100 mol parts of the compound (AE-1-1) was dissolved in N-methyl-2-pyrrolidone (NMP), and then 100 mol was added as a diamine. Parts of 4,4'-diaminodiphenylamine were dissolved. To this solution was added 300 mol parts of 4- (4,6-dimethoxy-1,3,5-triazin-2-yl) -4-methylmorpholinium chloride (DMT-MM, 15 ± 2% by weight of hydrate), and reacted at room temperature for 4 hours to obtain a solution containing the polymer (A-1-1) as a polyamidate. The weight average molecular weight Mw of the obtained polymer (A-1-1) was 91,000, and the polymer viscosity was 400 mPa · s. The polymer solution was left to stand at 20 ° C for 3 days, and as a result, it did not gel, and the storage stability was good.

[Synthesis Example 1-2 to Synthesis Example 1-4] Except changing the types and amounts of the tetracarboxylic acid diesters and diamines used in the reaction as described in Table 1 below, the same procedures were used as in Synthesis Example 1-1. Way to synthesize polyamidate. In addition, except that the types of the tetracarboxylic dianhydride and the compound (E) used were changed, a ring-opening reaction using the tetracarboxylic dianhydride of the compound (E) was performed in the same manner as in Synthesis Example 1-1. . Each of the polymer solutions obtained in Synthesis Examples 1-2 to 1-4 was left to stand at 20 ° C for 3 days. As a result, they did not gel, and the storage stability was good.

[Table 1]

Regarding the tetracarboxylic dianhydride, the numerical value in Table 1 represents the use ratio (mole%) with respect to the total amount of the tetracarboxylic dianhydride used in the reaction. For the diamine, the numerical value in Table 1 represents the relative The usage ratio (mole%) of the total amount of diamine used in the reaction (the same applies to the following Table 4, Table 7 and Table 10).

The abbreviations of the acid derivatives and diamines in Table 1 are as follows. (Acid derivative) AE-1-1: 1,2,3,4-cyclobutane tetracarboxylic dianhydride and 4-hydroxydiphenylamine (the compound represented by the formula (3-1-1) ) Reaction product AE-1-2: reaction product AE-1-3: 1 of pyromellitic dianhydride and 4-hydroxydiphenylamine (the compound represented by the formula (3-1-1)) , 2,3,4-cyclobutane tetracarboxylic acid diethyl ester (the reaction product of 1,2,3,4-cyclobutane tetracarboxylic dianhydride and ethanol) AN-1: 1,2,3,4 -Cyclobutane tetracarboxylic dianhydride (diamine) DA-1: 4,4'-diaminodiphenylamine DA-2: 4,4'-diaminodiphenyl ether

[Synthesis Example 1-5: Synthesis of Polymer (B-1-1)] 20 g of 1,2,3,4-cyclobutanetetracarboxylic dianhydride as a tetracarboxylic dianhydride was added to 200 mL Of ethanol. The obtained precipitate was separated by filtration, washed with ethanol, and dried under reduced pressure, whereby the compound (AE-1-3) was obtained as a tetracarboxylic acid diester in powder form. Then, 100 mol parts of the compound (AE-1-3) was dissolved in NMP, and then 100 mol parts of 4,4′-diaminodiphenylamine as a diamine were added thereto to dissolve them. To this solution was added 300 mol parts of 4- (4,6-dimethoxy-1,3,5-triazin-2-yl) -4-methylmorpholinium chloride (DMT-MM, 15 ± 2% by weight of hydrate), and reacted at room temperature for 4 hours to obtain a solution containing the polymer (B-1-1) as a polyamidate. The weight average molecular weight Mw of the obtained polymer (B-1-1) was 118,000, and the polymer viscosity was 520 mPa · s.

[Synthesis Example 1-6: Synthesis of Polymer (B-1-2)] 100 mol parts of 1,2,3,4-cyclobutane tetracarboxylic dianhydride as tetracarboxylic dianhydride, and 100 mols of 4,4'-diaminodiphenylamine as a diamine was dissolved in NMP, and a reaction was performed at 30 ° C for 6 hours to obtain a polymer (B-1-2) containing polyamic acid The solution. The obtained polymer solution was prepared to 15% by weight using NMP, and the polymer viscosity of the solution was measured to be 420 mPa · s.

[Synthesis Example 1-7: Synthesis of polymer (B-1-3)] 100 mol parts of pyromellitic dianhydride as a tetracarboxylic dianhydride and 100 mol parts of 1 as a diamine 5,5-bis (aminophenoxy) pentane was dissolved in NMP and reacted at 30 ° C. for 6 hours to obtain a solution containing the polymer (B-1-3) as a polyamic acid. The obtained polymer solution was prepared to 15% by weight using NMP, and the polymer viscosity of the solution was measured to be 380 mPa · s.

<Preparation and evaluation of liquid crystal alignment agent [1]> [Example 1-1] (1) Preparation of liquid crystal alignment agent The polymer (A-1-1) obtained in Synthesis Example 1-1 as a polymer was dissolved In a mixed solvent (NMP: BC = 50: 50 (weight ratio)) containing N-methyl-2-pyrrolidone (NMP) and butyl cellosolve (BC), a solution having a solid content concentration of 3.5% by weight was prepared. This solution was filtered through a filter having a pore size of 0.2 μm, thereby preparing a liquid crystal alignment agent (R1-1).

(2) Evaluation of the unevenness of the surface of the coating film Using the rotator, the prepared liquid crystal alignment agent (R1-1) was coated on a glass substrate, and pre-baked on a hot plate at 80 ° C. for one minute. A coating film having an average film thickness of 0.1 μm was formed by heating (post-baking) in an oven at 200 ° C. under nitrogen replacement for 1 hour. The surface of the obtained coating film was observed with an atomic force microscope (Atomic Force Microscope, AFM), and the center average roughness (Ra) was measured. The evaluation was performed as follows: the case where Ra was less than 5 nm was evaluated as "good", the case where 5 nm or more and less than 10 nm was evaluated as "good", and the case where 10 nm or more was evaluated as "bad". In this embodiment, Ra = 7 nm, and the surface unevenness is “OK”.

(3) Manufacturing of FFS-type liquid crystal display element by rubbing treatment The FFS-type liquid crystal display element 10 shown in Fig. 1 was manufactured. First, a pair of a glass substrate 11a having an electrode pair on one side and a counter glass substrate 11b not provided with an electrode are formed as a pair, and the electrode pair is sequentially formed with a bottom electrode 15 without a pattern and nitrogen as an insulating layer 14 The siliconized film and the top electrode 13 patterned into a comb-tooth shape are prepared by applying a spinner on the surface of the glass substrate 11a having a transparent electrode and the surface facing the glass substrate 11b using a spinner, respectively. Liquid crystal alignment agent (R1-1) to form a coating film. Next, the coating film was pre-baked on a hot plate at 80 ° C. for 1 minute, and then heated (post-baked) at 230 ° C. for 15 minutes in an oven in which nitrogen was replaced in the warehouse to form an average film thickness of 0.1. μm coating film. A schematic plan view of the top electrode 13 used therein is shown in FIGS. 2 (a) and 2 (b). 2A is a plan view of the top electrode 13, and FIG. 2B is an enlarged view of a portion C1 surrounded by a dotted line in FIG. 2A. In this embodiment, the line width d1 of the electrodes is set to 4 μm, and the distance d2 between the electrodes is set to 6 μm. In addition, the top electrode 13 is a driving electrode of four systems using an electrode A, an electrode B, an electrode C, and an electrode D. The structure of the driving electrode used is shown in FIG. In this case, the bottom electrode 15 functions as a common electrode that functions for all the drive electrodes of the four systems, and the areas of the drive electrodes of the four systems become pixel regions, respectively.

Next, each surface of the coating film formed on the glass substrates 11 a and 11 b was subjected to a rubbing treatment using cotton to prepare a liquid crystal alignment film 12. In FIG. 2 (b), the rubbing direction with respect to the coating film formed on the glass substrate 11 a is indicated by arrows. Next, one of the pair of substrates was coated with a sealant on the outer edge of the surface having the liquid crystal alignment film, and then these substrates were made antiparallel so that the rubbing directions of the substrates 11a and 11b were antiparallel, and the diameter was 3.5 μm The spacers come together to harden the sealant. Then, a liquid crystal MLC-6221 (manufactured by Merck) is injected between the pair of substrates from the liquid crystal injection port to form a liquid crystal layer 16. Furthermore, polarizing plates (not shown) are bonded to the outer surfaces of the substrates 11 a and 11 b so that the polarization directions of the two polarizing plates are orthogonal to each other, thereby producing a liquid crystal display element 10.

(4) Evaluation of DC afterimage characteristics (harsh conditions) For the FFS liquid crystal display device manufactured as described above, a voltage of 20 VDC was applied at an ambient temperature of 100 ° C for 500 hours, and a flicker elimination method was used to The voltage (residual DC voltage) remaining in the liquid crystal cell immediately after the DC voltage was cut off was determined. The evaluation was performed as follows: a case where the value of the residual DC voltage was less than 300 mV was evaluated as "good", a case where the value of 300 mV or more and less than 500 mV was evaluated as "good", and a case where the value was 500 mV or more was evaluated as "bad". . As a result, the value of the residual DC voltage of the liquid crystal display element in Example 1-1 was 50 mV, which was a "good" evaluation.

(5) Evaluation of DC afterimage characteristics (normal conditions) For the FFS liquid crystal display device manufactured as described above, a voltage of 10 V DC was applied at an ambient temperature of 25 ° C for 20 hours, and the flicker elimination method was used to determine the just cut off. The voltage remaining in the liquid crystal cell after the DC voltage (residual DC voltage). The evaluation was performed as follows: a case where the value of the residual DC voltage was less than 300 mV was evaluated as "good", a case where the value of 300 mV or more and less than 500 mV was evaluated as "good", and a case where the value was 500 mV or more was evaluated as "bad". . As a result, in Example 1-1, the value of the residual DC voltage of the liquid crystal display element was 10 mV, which was a "good" evaluation.

(6) Measurement of voltage holding ratio For the manufactured FFS-type liquid crystal display device, a voltage of 1 V was applied at 23 ° C for 0.5 microsecond application time and a span of 2000 milliseconds, and then measured after 2000 milliseconds after the application was cancelled. Voltage holding rate (VHR). The measurement device used was VHR-1 manufactured by Toyo Technica. The evaluation was performed as follows: a case where the voltage retention was 95% or more was evaluated as “good”, a case where 90% or more and less than 95% was evaluated as “yes”, and a case less than 90% was evaluated as “bad”. As a result, in Example 1-1, the voltage retention was 98%, which was a "good" result.

(7) Evaluation of reliability About the manufactured FFS-type liquid crystal display element, the voltage holding ratio was measured in the same manner as in (6) above, and the value was taken as the initial VHR (VHR _BF ). Next, the liquid crystal display element after the initial VHR measurement was left to stand in a 60 ° C. oven for 1,000 hours under light emitting diode (LED) light. Then, after the liquid crystal display element was left to stand at room temperature and was naturally cooled to room temperature, the voltage holding ratio (VHR _AF ) was measured in the same manner as in (6) above. In addition, the change rate (ΔVHR (%)) of the voltage holding rate before and after the stress was applied was determined using the following formula (EX-1). ΔVHR = ((VHR _BF -VHR _AF ) ÷ VHR _BF ) × 100… (EX-1) The reliability is evaluated as follows: The case where the rate of change ΔVHR is less than 10% is evaluated as “good”, and the value is more than 10% and less than 20 % Cases were evaluated as "OK", and 20% or more cases were evaluated as "Bad". As a result, in the liquid crystal display element of this example, ΔVHR = 4%, and the reliability was “good”.

[Example 1-2 to Example 1-6 and Comparative Example 1-1 to Comparative Example 1-2] Except changing the type and amount of the polymer to be used as described in Table 2 below, it was implemented in accordance with A liquid crystal alignment agent was prepared in the same manner as in Example 1-1. In addition, using the prepared liquid crystal alignment agent, a coating film and a liquid crystal display element were produced in the same manner as in Example 1-1, and various evaluations were performed. The evaluation results are shown in Table 3 below.

[Table 2]

[table 3]

As shown in Table 3, in Examples 1-1 to 1-6, the surface unevenness of the coating film, and the voltage retention ratio, DC afterimage characteristics, and reliability of the liquid crystal display element were all "good" or The result of "yes" is a balance of various characteristics. On the other hand, in the comparative example, the afterimage characteristics of DC are inferior to those of the embodiment.

<Synthesis of Polymer [2]> [Synthesis Example 2-1 to Synthesis Example 2-4] Except changing the types and amounts of the tetracarboxylic acid diester and diamine used in the reaction as described in Table 4 below, Polyamidate was synthesized in the same manner as in Synthesis Example 1-1. In addition, except that the types of the tetracarboxylic dianhydride and the compound (E) used were changed, a ring-opening reaction using the tetracarboxylic dianhydride of the compound (E) was performed in the same manner as in Synthesis Example 1-1. . Each polymer solution obtained in Synthesis Example 2-1 to Synthesis Example 2-4 was left to stand at 20 ° C for 3 days. As a result, it did not gel, and the storage stability was good.

[Table 4]

The abbreviations of the acid derivatives and diamines in Table 4 are as follows. (Acid derivative) AE-2-1: Reaction of 1,2,3,4-cyclobutanetetracarboxylic dianhydride with 4-hydroxypyridine (the compound represented by the formula (3-2-1)) Product AE-2-2: reaction product of pyromellitic dianhydride and 4-hydroxypyridine (the compound represented by the formula (3-2-1)) AE-2-3: 1, 2, 3, 4 -Diethyl cyclobutanetetracarboxylic acid (the reaction product of 1,2,3,4-cyclobutanetetracarboxylic dianhydride and ethanol) AN-1: 1,2,3,4-cyclobutanetetracarboxylic acid Acid dianhydride (diamine) DA-2: 4,4'-diaminodiphenyl ether DA-3: 2- (4-aminophenyl) -5-aminopyridine (wherein the formula (d-5) Represented compound)

[Synthesis Example 2-5: Synthesis of Polymer (B-2-1)] Diethyl 1,2,3,4-cyclobutanetetracarboxylate (compound was synthesized by the same operation as in Synthesis Example 1-5 (AE-2-3)). Next, 100 mol parts of the compound (AE-2-3) was dissolved in NMP, and then 100 mol parts of 2- (4-aminophenyl) -5-aminopyridine as a diamine were added thereto to make Its dissolved. To this solution was added 300 mol parts of 4- (4,6-dimethoxy-1,3,5-triazin-2-yl) -4-methylmorpholinium chloride (DMT-MM, 15 ± 2% by weight of hydrate), and reacted at room temperature for 4 hours to obtain a solution containing polymer (B-2-1) as a polyamidate. The weight average molecular weight Mw of the obtained polymer (B-2-1) was 80,000, and the polymer viscosity was 320 mPa · s.

[Synthesis Example 2-6: Synthesis of polymer (B-2-2)] 100 mol parts of 1,2,3,4-cyclobutanetetracarboxylic dianhydride as tetracarboxylic dianhydride, and 100 mol parts of 2- (4-aminophenyl) -5-aminopyridine as a diamine was dissolved in NMP, and a reaction was performed at 30 ° C for 6 hours to obtain a polymer (B-2-2) containing a polymer Amidine solution. The obtained polymer solution was prepared to 15% by weight using NMP, and the polymer viscosity of the solution was measured to be 300 mPa · s.

[Synthesis Example 2-7: Synthesis of Polymer (B-2-3)] By performing the same operation as in Synthesis Example 1-7, a polymer (B-2-3) was obtained as a tetramethylenebenzene A solution of formic acid dianhydride and 1,5-bis (aminophenoxy) pentane as a raw material.

<Preparation and evaluation of liquid crystal alignment agent [2]> [Example 2-1] (1) Preparation of liquid crystal alignment agent The polymer (A-2-1) obtained in Synthesis Example 2-1 as a polymer was dissolved In a mixed solvent (NMP: BC = 50: 50 (weight ratio)) containing NMP and butyl cellosolve (BC), a solution having a solid content concentration of 3.5% by weight was prepared. This solution was filtered through a filter having a pore size of 0.2 μm, thereby preparing a liquid crystal alignment agent (R2-1).

(2) The evaluation of the unevenness of the surface of the coating film was performed in the same manner as in Example 1-1 except that the liquid crystal alignment agent used was changed to the liquid crystal alignment agent (R2-1) obtained in (1). 2) The same operation was performed to evaluate the surface unevenness of the coating film. As a result, in this example, Ra = 9 nm, and the surface unevenness was “OK”. (3) The manufacturing of the FFS liquid crystal display element was performed in the same manner as in (1) of Example 1-1 except that the liquid crystal alignment agent used was changed to the liquid crystal alignment agent (R2-1) obtained in (1). ) The same operation is performed, thereby manufacturing an FFS-type liquid crystal display element. (4) Measurement of voltage holding ratio The voltage holding ratio (VHR) of the FFS liquid crystal display element manufactured in the above (3) was measured in the same manner as in (6) of the above-mentioned Example 1-1. As a result, the VHR was 99%, which was a "good" result. (5) Evaluation of reliability Regarding the FFS-type liquid crystal display element manufactured in the above (3), the voltage retention ratios (VHR _BF and VHR _AF ) were measured in the same manner as in the above (7) of Example 1-1. In addition, the reliability of the liquid crystal display element was evaluated based on the change rate ΔVHR of the voltage holding rate before and after the stress application. As a result, ΔVHR was 6%, and it was determined that the reliability was “good”.

[Example 2-2 to Example 2-6, and Comparative Example 2-1 to Comparative Example 2-2] Except changing the type and amount of the polymer as described in Table 5 below, it was the same as in Example 2 1 A liquid crystal alignment agent was prepared in the same manner. In addition, using the prepared liquid crystal alignment agent, a coating film and a liquid crystal display element were produced in the same manner as in Example 2-1, and various evaluations were performed. The evaluation results are shown in Table 6 below.

[table 5]

[TABLE 6]

As shown in Table 6, in Examples 2-1 to 2-6, the results of the surface roughness of the coating film, and the voltage holding ratio and reliability of the liquid crystal display element were all "good" or "possible" results. To achieve a balance of various characteristics. On the other hand, in the comparative example, the reliability evaluation was inferior to the example.

<Synthesis of Polymer [3]> [Synthesis Example 3-1 to Synthesis Example 3-5] Except changing the types and amounts of the tetracarboxylic acid diester and diamine used in the reaction as described in Table 7 below, Polyamidate was synthesized in the same manner as in Synthesis Example 1-1. In addition, except that the types of the tetracarboxylic dianhydride and the compound (E) used were changed, a ring-opening reaction using the tetracarboxylic dianhydride of the compound (E) was performed in the same manner as in Synthesis Example 1-1. . Each of the polymer solutions obtained in Synthesis Examples 3-1 to 3-5 was left to stand at 20 ° C. for 3 days. As a result, they did not gel, and the storage stability was good.

[TABLE 7]

The abbreviations of the acid derivatives and diamines in Table 7 are as follows. (Acid derivative) AE-3-1: reaction product of 2,3,5-tricarboxycyclopentylacetic dianhydride and 2-hydroxyethyl methacrylate AE-3-2: bicyclic [3.3.0] octyl Reaction product of alkane-2,4,6,8-tetracarboxylic dianhydride and 2-hydroxyethyl methacrylate AE-3-3: reaction of pyromellitic dianhydride with 2-hydroxyethyl methacrylate Product AE-3-4: Reaction of 2,3,5-tricarboxycyclopentylacetic dianhydride with ethanol AN-2: 2,3,5-tricarboxycyclopentylacetic dianhydride (diamine) DA- 4: Compound in which R ⁸ is a methyl group in the formula (d-6) DA-5: Cholesteryloxy-2,4-diaminobenzene DA-6: p-phenylenediamine

[Synthesis Example 3-6: Synthesis of Polymer (B-3-1)] 20 g of 2,3,5-tricarboxycyclopentylacetic dianhydride as tetracarboxylic dianhydride was added to 200 mL of ethanol in. The obtained precipitate was separated by filtration, washed with ethanol, and then dried under reduced pressure to obtain a compound (AE-3-4) as a tetracarboxylic acid diester in powder form. Next, 100 mol parts of the compound (AE-3-4) was dissolved in NMP, and then 100 mol parts of the compound (DA-4) was added as a diamine to dissolve them. To this solution was added 300 mol parts of 4- (4,6-dimethoxy-1,3,5-triazin-2-yl) -4-methylmorpholinium chloride (DMT-MM, 15 ± 2% by weight of hydrate), and reacted at room temperature for 4 hours to obtain a solution containing polymer (B-3-1) as a polyamidate. The weight average molecular weight Mw of the obtained polymer (B-3-1) was 103,000, and the polymer viscosity was 450 mPa · s.

[Synthesis Example 3-7: Synthesis of polymer (B-3-2)] 100 mol parts of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride, and A 100 mole portion of the compound (DA-4) of amine was dissolved in NMP, and a reaction was performed at 30 ° C for 6 hours to obtain a solution containing the polymer (B-3-2) as a polyamic acid. The obtained polymer solution was prepared to 15% by weight using NMP, and the polymer viscosity of the solution was measured to be 280 mPa · s.

[Synthesis Example 3-8: Synthesis of Polymer (B-3-3)] In addition to using 1,2,3,4-cyclobutanetetracarboxylic dianhydride as a tetracarboxylic dianhydride, Except for the aspect of phenylenediamine, the same operation as in Synthesis Example 1-7 was performed to obtain a solution containing the polymer (B-3-3) as a polyamic acid. The obtained polymer solution was prepared to 15% by weight using NMP, and the polymer viscosity of the solution was measured to be 320 mPa · s.

<Preparation and evaluation of liquid crystal alignment agent [3]> [Example 3-1] (1) Preparation of liquid crystal alignment agent The polymer (A-3-1) obtained in Synthesis Example 3-1 as a polymer was dissolved In a mixed solvent (NMP: BC = 50: 50 (weight ratio)) containing NMP and butyl cellosolve (BC), a solution having a solid content concentration of 3.5% by weight was prepared. This solution was filtered through a filter having a pore size of 0.2 μm, thereby preparing a liquid crystal alignment agent (R3-1).

(2) Evaluation of the unevenness of the surface of the coating film was performed in the same manner as in Example 1-1 except that the liquid crystal alignment agent used was changed to the liquid crystal alignment agent (R3-1) obtained in (1). 2) The same operation was performed to evaluate the surface unevenness of the coating film. As a result, in this example, Ra = 8 nm, and the surface unevenness was “OK”. (3) Production of VA-type liquid crystal cell A liquid crystal alignment film printer (manufactured by Japan Photo Printing Co., Ltd.) was used, and the liquid crystal alignment agent (R3-1) prepared in the above (1) was coated with a patterned Each electrode surface of the two glass substrates of the slit-shaped ITO electrode divided into a plurality of regions was heated (pre-baked) on a heating plate at 80 ° C for 1 minute to remove the solvent, and then heated at 150 ° C. The plate is heated (post-baked) for 10 minutes to form a coating film with an average film thickness of 600 Å. This coating film was subjected to ultrasonic washing in ultrapure water for 1 minute, and then dried in a 100 ° C. clean oven for 10 minutes, thereby obtaining a substrate having a coating film to be a liquid crystal alignment film. This operation was repeated to obtain a pair (two pieces) of substrates having a coating film. The pattern of the electrode used is the same pattern as the electrode pattern in the PSA mode. Next, the outer edges of the pair of substrates having the coating film were coated with an epoxy resin adhesive with alumina balls having a diameter of 5.5 μm, and the coating surfaces were overlapped and crimped so as to make the adhesive The adhesive is hardened. Next, a nematic liquid crystal (Merck, MLC-6608, manufactured by Merck) was filled between the pair of substrates from the liquid crystal injection port, and then the liquid crystal injection port was sealed with an acrylic light-curing adhesive. Then, an AC 10 V having a frequency of 60 Hz was applied between the electrodes of the obtained liquid crystal cell, and the liquid crystal was driven with an ultraviolet irradiation device using a metal halide lamp using a light source at an irradiation amount of 100,000 J / m ² . The outside of the liquid crystal cell is irradiated with ultraviolet rays. It should be noted that the exposure amount is a value measured using a light meter that measures at a wavelength of 365 nm.

(4) Measurement of pretilt angle The liquid crystal cell manufactured as described above was used to measure the pretilt angle. Here, according to the non-patent literature (TJ Scheffer et al., "Journal of Applied Physics (J. Appl. Phys.)" Vol. 19, 2013 (1980)) As a method, a value of an inclination angle of a liquid crystal molecule from a substrate surface measured by a crystal rotation method using He-Ne laser light was used as a pretilt angle. The evaluation was performed as follows: a case where the measured value of the pretilt angle was less than 88.0 ° was evaluated as “good”, a case where 88.0 ° or more and less than 89.0 ° was evaluated as “yes”, and a case where 89.0% or more was evaluated as “bad”. . As a result, it was 87.0 ° in this example, which was an evaluation of "good" pretilt angle characteristics. (5) Measurement of voltage holding ratio For the liquid crystal cell manufactured in the above (3), the voltage holding ratio (VHR) was measured in the same manner as in (6) of Example 1-1. As a result, the VHR was 97%, which was a "good" result. (6) Evaluation of Reliability For the liquid crystal cell manufactured in the above (3), the voltage holding ratios (VHR _BF and VHR _AF ) were measured in the same manner as in the above (7) of Example 1-1. In addition, the reliability of the liquid crystal display element was evaluated based on the change rate ΔVHR of the voltage holding rate before and after the stress application. As a result, the ΔVHR was 5%, and the reliability was judged to be “good”.

[Example 3-2 to Example 3-7, and Comparative Example 3-1 to Comparative Example 3-2] Except changing the type and amount of the polymer as described in Table 8 below, it was the same as that of Example 3 1 A liquid crystal alignment agent was prepared in the same manner. In addition, using the prepared liquid crystal alignment agent, a coating film and a liquid crystal cell were prepared in the same manner as in Example 3-1, and various evaluations were performed. The evaluation results are shown in Table 9 below.

[TABLE 8]

[TABLE 9]

As shown in Table 9, in Examples 3-1 to 3-7, the surface roughness of the coating film, and the pretilt characteristics, voltage retention, and reliability of the liquid crystal display element were all "good" or " May "result. In contrast, in the comparative example, it is difficult to provide a pretilt angle.

<Synthesis of Polymer [4]> [Synthesis Example 4-1 to Synthesis Example 4-4] Except changing the types and amounts of the tetracarboxylic acid diester and diamine used in the reaction as described in Table 10 below, Polyamidate was synthesized in the same manner as in Synthesis Example 1-1. In addition, except that the types of the tetracarboxylic dianhydride and the compound (E) used were changed, a ring-opening reaction using the tetracarboxylic dianhydride of the compound (E) was performed in the same manner as in Synthesis Example 1-1. . Each polymer solution obtained in Synthesis Example 4-1 to Synthesis Example 4-4 was left to stand at 20 ° C for 3 days. As a result, it did not gel, and the storage stability was good.

[TABLE 10]

The abbreviations of the acid derivatives and diamines in Table 10 are as follows. (Acid derivative) AE-4-1: Reaction product AE-4-2 of pyromellitic dianhydride and 4-hydroxyphenyl benzoate (the compound represented by the formula (3-4-1)) : Reaction product AE-4-3 of 2,3,5-tricarboxycyclopentylacetic dianhydride and 4-hydroxyphenyl benzoate (the compound represented by the formula (3-4-1)): both Reaction product of pyromellitic dianhydride and ethanol AN-3: pyromellitic dianhydride (diamine) DA-6: p-phenylenediamine DA-7: 4-aminophenyl-4'-aminobenzoate

[Synthesis Example 4-5: Synthesis of Polymer (B-4-1)] 20 g of pyromellitic dianhydride as tetracarboxylic dianhydride was added to 200 mL of ethanol. The obtained precipitate was separated by filtration, washed with ethanol, and dried under reduced pressure to obtain a compound (AE-4-3) as a tetracarboxylic acid diester in powder form. Next, 100 mol parts of the compound (AE-4-3) was dissolved in NMP, and then 100 mol parts of 4-aminophenyl-4'-aminobenzoate as a diamine was added thereto to make Its dissolved. To this solution was added 300 mol parts of 4- (4,6-dimethoxy-1,3,5-triazin-2-yl) -4-methylmorpholinium chloride (DMT-MM, 15 ± 2% by weight of hydrate), and reacted at room temperature for 4 hours to obtain a solution containing polymer (B-4-1) as a polyamidate. The weight average molecular weight Mw of the obtained polymer (B-4-1) was 97,000, and the polymer viscosity was 420 mPa · s.

[Synthesis Example 4-6: Synthesis of Polymer (B-4-2)] 100 mol parts of pyromellitic dianhydride as a tetracarboxylic dianhydride and 4 mol parts of 100 mol as a diamine -Aminophenyl-4'-aminobenzoate was dissolved in NMP and reacted at 30 ° C for 6 hours to obtain a solution containing polymer (B-4-2) as a polyamic acid. The obtained polymer solution was prepared to 15% by weight using NMP, and the polymer viscosity of the solution was measured to be 350 mPa · s.

[Synthesis Example 4-7: Synthesis of Polymer (B-4-3)] Except the use of 1,2,3,4-cyclobutane tetracarboxylic dianhydride as a tetracarboxylic dianhydride, and Except for the aspect of phenylenediamine, the same operation as in Synthesis Example 1-7 was performed to obtain a solution containing the polymer (B-4-3) as a polyamic acid.

<Preparation and evaluation of liquid crystal alignment agent [4]> [Example 4-1] (1) Preparation of liquid crystal alignment agent The polymer (A-4-1) obtained in Synthesis Example 4-1 as a polymer was dissolved In a mixed solvent (NMP: BC = 50: 50 (weight ratio)) containing NMP and butyl cellosolve (BC), a solution having a solid content concentration of 3.5% by weight was prepared. This solution was filtered through a filter having a pore size of 0.2 μm, thereby preparing a liquid crystal alignment agent (R4-1). (2) Evaluation of the unevenness of the surface of the coating film was performed in the same manner as in Example 1-1 except that the liquid crystal alignment agent used was changed to the liquid crystal alignment agent (R4-1) obtained in (1). 2) The same operation was performed to evaluate the surface unevenness of the coating film. As a result, Ra = 9 nm and the surface unevenness was “OK” in this example.

(3) Manufacturing of the FFS liquid crystal display element using the photo-alignment method Using a spinner, each surface of a pair of glass substrates 11a, 11b same as (3) of Example 1-1 was coated with the above ( 1) The liquid crystal alignment agent (R4-1) prepared in 1) to form a coating film. Next, the coating film was pre-baked on a hot plate at 80 ° C for 1 minute, and then heated (post-baked) at 230 ° C for 15 minutes in an oven replaced with nitrogen in the warehouse to form an average film thickness of 1,000. Å coating film. A schematic plan view of the top electrode 13 used therein is shown in FIGS. 4 (a) and 4 (b). In addition, FIG. 4 (a) is a plan view of the top electrode 13, and FIG. 4 (b) is an enlarged view of a portion C1 surrounded by a dotted line in FIG. 4 (a). In this embodiment, a substrate having a top electrode with a line width d1 of the electrodes of 4 μm and a distance d2 between the electrodes of 6 μm is used. In addition, as the top electrode 13, the driving electrodes of the four systems of the electrode A, the electrode B, the electrode C, and the electrode D are used (see FIG. 3) in the same manner as in (3) of the embodiment 1-1. Next, for each surface of these coating films, Hg-Xe lamps and Glan Taylor prisms were used to irradiate 300 J / m ² of polarized ultraviolet light including 313 nm bright lines from the substrate normal direction to obtain a liquid crystal alignment film. A pair of substrates. At this time, the irradiation direction of the polarized ultraviolet rays is set from the normal direction of the substrate, and the direction of the line segment projecting the polarized surface of the polarized ultraviolet rays on the substrate is set to the direction of the double-headed arrow in FIG. 4, and then Light irradiation treatment.

Next, one of the substrates was coated with an epoxy resin adhesive having alumina balls having a diameter of 5.5 μm by screen printing on the outer periphery of a surface having a liquid crystal alignment film on the substrate, and then a pair of substrates was applied. The liquid crystal alignment film is face-to-face, superimposed and crimped so that the direction in which the polarized surface of polarized ultraviolet rays is projected onto the substrate becomes parallel, and the adhesive is thermally cured at 150 ° C for 1 hour. Then, the liquid crystal injection port was filled with a liquid crystal "MLC-6221" manufactured by Merck, and then the liquid crystal injection port was sealed with an epoxy resin adhesive. Then, in order to eliminate the flow alignment during the liquid crystal injection, it was heated to 150 ° C. and then slowly cooled to room temperature. Furthermore, polarizing plates are bonded to both outer surfaces of the substrates 11a and 11b, thereby producing a liquid crystal display element. At this time, one of the polarizing plates is attached in such a manner that the polarization direction becomes parallel to the projection direction of the polarized surface of the polarized ultraviolet rays of the liquid crystal alignment film on the substrate surface, and the other is based on the polarization direction and The polarizing plates are attached in such a manner that the polarization directions are orthogonal.

(4) Evaluation of AC afterimage characteristics The FFS-type liquid crystal display element manufactured in (3) was placed in an environment of 25 ° C and 1 atmosphere. The bottom electrode was used as a common electrode for all the driving electrodes of the four systems, and the potential of the bottom electrode was set to a potential of 0 V (ground potential). While the electrodes B and D and the common electrode were short-circuited to a 0 V application state, a combined voltage including an AC voltage of 5 V was applied to the electrodes A and C for 100 hours. Immediately after 100 hours, a voltage of 1.5 V AC was applied to all of the electrodes A to D. Then, from the moment when the voltage of AC 1.5 V was applied to all of the electrodes A to D, the driving stress application area (pixel area of electrode A and electrode C) and the driving stress non-application area were no longer visually confirmed. (The pixel area of the electrode B and the electrode D) is defined as the afterimage erasing time Ts. In addition, the shorter this time, the more difficult it is to generate an afterimage. The case where the afterimage erasing time Ts is less than 30 seconds is evaluated as "good", the case where 30 seconds or more and less than 120 seconds is evaluated as "OK", and the case where 120 seconds or more is evaluated as "bad". As a result, this embodiment The afterimage erasing time Ts of the liquid crystal display element was 10 seconds, and it was evaluated that the afterimage characteristics were "good".

(5) Measurement of voltage holding ratio The voltage holding ratio (VHR) of the FFS liquid crystal display element manufactured in the above (3) was measured in the same manner as in (6) of the above-mentioned Example 1-1. As a result, the VHR was 96%, which was a "good" result. (6) Evaluation of reliability Using the liquid crystal display element manufactured in the above (3), the voltage holding ratios (VHR _BF and VHR _AF ) were measured in the same manner as in the above (7) of Example 1-1. In addition, the reliability of the liquid crystal display element was evaluated based on the change rate ΔVHR of the voltage holding rate before and after the stress application. As a result, ΔVHR was 12%, and the reliability was evaluated as “OK”.

[Example 4-2 to Example 4-6, and Comparative Example 4-1 to Comparative Example 4-2] Except changing the type and amount of the polymer as described in Table 11 below, it was the same as that of Example 4- 1 A liquid crystal alignment agent was prepared in the same manner. In addition, using the prepared liquid crystal alignment agent, a coating film and a liquid crystal cell were produced in the same manner as in Example 4-1, and various evaluations were performed. The evaluation results are shown in Table 12 below.

[TABLE 11]

[TABLE 12]

As shown in Table 12, in Examples 4-1 to 4-6, the surface roughness of the coating film and the AC afterimage characteristics, voltage retention, and reliability of the liquid crystal display element were all "good" or "May" result. On the other hand, in the comparative example, the evaluation of the AC afterimage characteristics as "bad" was inferior to the examples.

10‧‧‧ Liquid crystal display element

11a, 11b‧‧‧ glass substrate

12‧‧‧LCD alignment film

13‧‧‧top electrode

14‧‧‧ Insulation

15‧‧‧ bottom electrode

16‧‧‧LCD layer

d1‧‧‧ electrode line width

d2‧‧‧Distance between electrodes

A, B, C, D, E‧‧‧ electrodes

F‧‧‧ pixel edge part

FIG. 1 is a schematic configuration diagram of an FFS-type liquid crystal cell. FIG. 2 (a) and FIG. 2 (b) are schematic plan views of a top electrode used for manufacturing a liquid crystal display element by rubbing treatment. (A) of FIG. 2 is a top view of the top electrode, and (b) of FIG. 2 is an enlarged view of a part of the top electrode. FIG. 3 is a diagram showing drive electrodes of the system. 4 (a) and 4 (b) are schematic plan views of a top electrode used when a liquid crystal display element is manufactured by a photo-alignment process. (A) of FIG. 4 is a top view of the top electrode, and (b) of FIG. 4 is an enlarged view of a part of the top electrode.

Claims (3)

A liquid crystal alignment agent comprising a polymer (P) having a partial structure represented by the following formula (1), (In formula (1), R ¹ is a tetravalent organic group and R ² is a divalent organic group; X ¹ and X ² are each independently a hydroxyl group or a monovalent organic group having 1 to 40 carbon atoms; wherein X ¹ and At least one of X ² is a heterocyclic group), and at least one polymer (Q) selected from the group consisting of polyamidic acid and polyamidoimine. A liquid crystal alignment film is formed by using the liquid crystal alignment agent according to item 1 of the scope of patent application. A liquid crystal display element, comprising the liquid crystal alignment film according to item 2 of the scope of patent application.