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

Abstract

The invention provides a liquid crystal aligning agent, a liquid crystal alignment film and a liquid crystal display element using the liquid crystal alignment film. The liquid crystal aligning agent can obtain a liquid crystal alignment film capable of suppressing AC residual images at a higher level than in the prior art. The liquid crystal aligning agent is characterized by containing at least one polymer (A) selected from the group consisting of polyimide precursors having a repeating unit (a1) represented by formula (1) and polyimides that are imides of the polyimide precursors. # imgabs0 # (X1 represents a tetravalent organic group); r1 and R2 each independently represent a hydrogen atom, a fluorine atom, or a monovalent organic group having 1 carbon atoms, and at least one of R1 represents a fluorine atom or a monovalent organic group having 1 carbon atoms. And L represents an alkylene group having 1-2 carbon atoms. R and Z each independently represent a hydrogen atom or a monovalent organic group. And a plurality of R1, R, and Z are each independently defined above.)

Description

Technical Field

[0001] The present invention relates to a liquid crystal aligning agent, a liquid crystal alignment film, and a liquid crystal display element. Background Art

[0002] Liquid crystal display devices are widely used as display units for personal computers, smartphones, mobile phones, televisions, and the like. A liquid crystal display device generally includes: a liquid crystal layer sandwiched between a display element substrate and a color filter substrate; pixel electrodes and a common electrode for applying an electric field to the liquid crystal layer; an alignment film for controlling the alignment of liquid crystal molecules in the liquid crystal layer; a thin film transistor (TFT: Thin Film Transistor) for switching an electric signal supplied to the pixel electrode; and the like. As driving methods for liquid crystal molecules, known are longitudinal electric field methods such as TN (Twisted Nematic) method and VA (Vertical Alignment) method; an IPS (In Plane Switching) driving method; and transverse electric field methods such as FFS (Fringe Field Switching) driving method.

[0003] The most widely used liquid crystal alignment film in industry is produced by performing a so-called rubbing treatment, which is a unidirectional rubbing of the surface of a film formed on an electrode substrate and made of polyamic acid and / or polyimide obtained by imidizing the polyamic acid, using a cloth such as cotton, nylon, or polyester. The rubbing treatment is a simple and industrially useful method with excellent productivity. As an alignment treatment method alternative to the rubbing treatment, a photo-alignment method of imparting liquid crystal alignment ability by irradiating polarized radiation is known. Regarding the photo-alignment method, methods using a photoisomerization reaction, a photocrosslinking reaction, a photodecomposition reaction, etc. have been proposed (for example, refer to Non-Patent Document 1, Patent Documents 1, 2, and 3).

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent Laid-Open No. 9-297313

[0007] Patent Document 2: Japanese Patent Laid-Open No. 2004-206091

[0008] Patent Document 3: WO2017 / 047596

[0009] Non-Patent Documents

[0010] Non-Patent Document 1: "Functional Materials", November 1997 issue, Vol. 17, No. 11, pages 13 to 22 Summary of the Invention

[0011] Problems to be Solved by the Invention

[0012] In recent years, large-screen and high-definition liquid crystal display elements have become the mainstay. In addition, the popularization of small display terminals such as smartphones, tablet PCs, and car navigation systems is being promoted, and the requirement for higher quality of liquid crystal display elements has been further increased compared to the past. In particular, in the liquid crystal alignment films used in liquid crystal display elements typified by the IPS method and the FFS method, a high alignment restraining force is required to suppress afterimages (hereinafter, also referred to as AC afterimages) generated by long-term AC driving.

[0013] Therefore, in view of the above, an object of the present invention is to provide a liquid crystal aligning agent, the following liquid crystal alignment film, and a liquid crystal display element using the following liquid crystal alignment film, wherein the liquid crystal aligning agent can obtain a liquid crystal alignment film that suppresses AC afterimages at a higher level than in the past.

[0014] Solutions to the Problems

[0015] The present inventors conducted intensive studies and found that the above technical problems can be solved by using a liquid crystal aligning agent containing a specific component, thereby completing the present invention.

[0016] Specifically, the present invention has the following solutions.

[0017] One aspect of the present invention is a liquid crystal aligning agent, characterized by containing at least one polymer (A) selected from the group consisting of a polyimide precursor having a repeating unit (a1) represented by the following formula (1) and a polyimide which is an imidized product of the polyimide precursor.

[0018]

[0019] (X1 represents a tetravalent organic group. R1 and R2 each independently represent a hydrogen atom, a fluorine atom, or a monovalent organic group having 1 carbon atom, and at least one of R1 represents a fluorine atom or a monovalent organic group having 1 carbon atom. L represents an alkylene group having 1 to 2 carbon atoms. R and Z each independently represent a hydrogen atom or a monovalent organic group. A plurality of R1, R, and Z each independently have the above definitions.)

[0020] Another aspect of the present invention is a liquid crystal aligning agent, characterized by containing at least one polymer (A') selected from the group consisting of a polyimide precursor having a repeating unit (a1') represented by the following formula (1') and a polyimide which is an imidized product of the polyimide precursor.

[0021]

[0022] (X 1’ represents a tetravalent organic group selected from the following formulas (X-1) to (X-9). R 1’ and R 2’ each independently represent a hydrogen atom, a fluorine atom or a monovalent organic group having 1 carbon atom, and at least one of R 1’ represents a fluorine atom or a monovalent organic group having 1 carbon atom. L’ represents an alkylene group having 1 to 12 carbon atoms, a cyclohexylene group, a phenylene group, a biphenyl structure or a naphthylene group. R’ and Z’ each independently represent a hydrogen atom or a monovalent organic group. A plurality of R 1’ , R 2’ , R’ and Z’ each independently have the above definitions.)

[0023]

[0024] (R1 to R4 each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, a monovalent organic group having 1 to 6 carbon atoms containing a fluorine atom or a phenyl group, and at least one of R1 to R4 represents a group other than a hydrogen atom in the above definition. * represents a bonding bond.)

[0025] It should be noted that in the whole of this specification, the meanings of the following terms and abbreviations are as described below. A halogen atom is a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc.

[0026] * represents a bonding bond in any case. In addition, Boc represents tert-butoxycarbonyl and Fmoc represents 9-fluorenylmethoxycarbonyl.

[0027] Advantages of the Invention

[0028] According to the present invention, a liquid crystal aligning agent, the following liquid crystal alignment film, and a liquid crystal display element using the following liquid crystal alignment film can be provided, and the liquid crystal aligning agent can obtain a liquid crystal alignment film that suppresses AC afterimages at a higher level than before.

[0029] The mechanism by which the present invention achieves the above effects is not necessarily clear, but the following is considered to be one of the reasons. It is considered that due to the steric hindrance of R1 in formula (1) and R 1’ in formula (1’), the imidization reaction is hindered when the resin film of polymer (A) or polymer (A’) is fired, and a polymer having a carboxyl group remaining therein is formed respectively. Therefore, it is considered that hydrogen bonds can be formed between the polymer chains to obtain the above effects.

[0030] In addition, it is considered that the polymer having a carboxyl group remaining after the above firing can moderately control a photoreaction represented by a photodecomposition reaction, and can suppress a decrease in the molecular weight of the resin film after the photoalignment treatment, and thus the above effects are obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 FIG. 1 is a schematic cross-sectional view showing an example of a lateral electric field liquid crystal display element having a liquid crystal alignment film obtained from the liquid crystal aligning agent of the present invention.

[0032] Figure 2 FIG. 2 is a schematic cross-sectional view showing another example of a lateral electric field liquid crystal display element having a liquid crystal alignment film obtained from the liquid crystal aligning agent of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0033] <Polymer (A)>

[0034] One embodiment of the liquid crystal aligning agent of the present invention contains at least one polymer (A) selected from the group consisting of a polyimide precursor having a repeating unit (a1) represented by the above formula (1) and a polyimide which is an imidized product of the polyimide precursor. It should be noted that the polymer (A) may be composed of one or two or more polymers. In addition, the repeating units constituting the polymer (A) may be one repeating unit or two or more different repeating units.

[0035] In the above formula (1), L represents an alkylene group having 1 to 2 carbon atoms, preferably an alkylene group having 2 carbon atoms.

[0036] Examples of the monovalent organic group for R and Z in the above formula (1) include: a monovalent hydrocarbon group having 1 to 20 carbon atoms, a group in which one or more non-adjacent methylene groups in the hydrocarbon group are replaced by -O-, -S-, -CO-, -COO-, -COS-, -NR 3 -, -CO-NR 3 -, -Si(R 3 )2-, -SO2-, etc. (wherein R 3 is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, and when there are a plurality of R 3 , each R 3 may be the same or different); a monovalent group in which at least one of the hydrogen atoms bonded to the carbon atom of the monovalent hydrocarbon group or the monovalent group A is replaced by a halogen atom, a hydroxyl group, an alkoxy group, a nitro group, an amino group, a mercapto group, a nitroso group, an alkylsilyl group, an alkoxysilyl group, a silanol group, a sulfino group, a phosphino group, a carboxyl group, a cyano group, a sulfo group, an acyl group, etc.; a monovalent group having a heterocycle; etc. As the monovalent organic group for R and Z in the above formula (1), an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, Boc or Fmoc are preferred, and an alkyl group having 1 to 3 carbon atoms is more preferred, and methyl is even more preferred.

[0037] From the viewpoint of suitably achieving the effects of the present invention, R and Z each independently preferably represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, more preferably a hydrogen atom or a methyl group.

[0038] In the benzene ring to which R1 in the above formula (1) is bonded, it is bonded adjacent to the bonding position of -N(Z)-. At least one fluorine atom or a monovalent organic group having 1 carbon atom (R1) is bonded adjacent to the bonding position of -N(Z)-. Therefore, compared with the case where it is bonded to the meta-position or para-position, the desired effect of the present invention of being able to suppress the AC afterimage at a higher level than before can be obtained.

[0039] Examples of the monovalent organic group having 1 carbon atom in R1 of the above formula (1) include: methyl group, methoxy group, trifluoromethyl group, cyano group, etc.

[0040] At least one of R1 in the above formula (1) is preferably a methyl group or a methoxy group. At least two of R1 in the above formula (1) can be a fluorine atom or a monovalent organic group having 1 carbon atom.

[0041] In the benzene ring to which R2 in the above formula (1) is bonded, it is bonded meta to the bonding position of -N(Z)-. R2 each independently represents a hydrogen atom, a fluorine atom or a monovalent organic group having 1 carbon atom. From the viewpoint of suitably achieving the effects of the present invention, it is preferred that all R2 be hydrogen atoms. The formula (1) in the case where all R2 are hydrogen atoms is represented by the following formula (1-1).

[0042]

[0043] (X1 represents a tetravalent organic group.

[0044] R1 each independently represents a hydrogen atom, a fluorine atom or a monovalent organic group having 1 carbon atom, and at least one of R1 represents a fluorine atom or a monovalent organic group having 1 carbon atom.

[0045] L represents an alkylene group having 1 to 2 carbon atoms.

[0046] (R and Z each independently represent a hydrogen atom or a monovalent organic group. A plurality of R1, R, and Z each independently have the above definitions.)

[0047] As preferred specific examples of the divalent organic group *-(benzene ring substituted by two R1 and two R2)-O-L-O-(benzene ring substituted by two R1 and two R2)-*(hereinafter, also referred to as divalent organic group (Y1)) possessed by the above formula (1), structures of the following formulas (Y1-1) to (Y1-4) can be cited.

[0048]

[0049] In the above formula (1), X1 represents a tetravalent organic group, preferably a tetravalent tetracarboxylic acid residue. Among them, as the tetravalent tetracarboxylic acid residue, for example, a tetravalent organic group existing between four carbonyl groups of a tetracarboxylic dianhydride or its derivative (for example, tetracarboxylic acid, tetracarboxylic dihalide, tetraalkyl ester of tetracarboxylic acid or tetraalkyl ester dihalide of tetracarboxylic acid, etc.) can be cited.

[0050] From the viewpoint of appropriately obtaining the effects of the present invention, among the above X1, a tetravalent tetracarboxylic acid residue derived from an acyclic aliphatic tetracarboxylic dianhydride, an alicyclic tetracarboxylic dianhydride, an aromatic tetracarboxylic dianhydride or a derivative thereof is preferred.

[0051] Among the tetracarboxylic dianhydrides or their derivatives providing the above X1, a tetracarboxylic dianhydride or its derivative having at least one partial structure selected from the group consisting of a benzene ring, a cyclobutane ring, a cyclopentane ring and a cyclohexane ring is more preferred, and a tetracarboxylic dianhydride or its derivative having at least one partial structure selected from the group consisting of a cyclobutane ring, a cyclopentane ring and a cyclohexane ring is further preferred.

[0052] Among them, the acyclic aliphatic tetracarboxylic dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxyl groups bonded to a chain hydrocarbon structure. Among them, it does not need to be composed only of a chain hydrocarbon structure, and an alicyclic structure or an aromatic ring structure may be present in a part thereof.

[0053] The alicyclic tetracarboxylic dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxyl groups including at least one carboxyl group bonded to an alicyclic structure. Among them, none of these four carboxyl groups is bonded to an aromatic ring. In addition, it does not need to be composed only of an alicyclic structure, and a chain hydrocarbon structure or an aromatic ring structure may be present in a part thereof.

[0054] The aromatic tetracarboxylic dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxyl groups including at least one carboxyl group bonded to an aromatic ring. Among them, it does not need to be composed only of an aromatic ring structure, and a chain hydrocarbon structure or an alicyclic structure may be present in a part thereof.

[0055] From the viewpoint of appropriately obtaining the effects of the present invention, X1 in the above formula (1) is preferably a tetravalent organic group represented by any of the following formulas (X-1) to (X-27), the following formulas (Xa-1) to (Xa-2) or the following formulas (Xr-1) to (Xr-7), and more preferably a tetravalent organic group represented by any of the following formulas (X-1) to (X-9).

[0056]

[0057] (Each of R1 to R4 independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, a monovalent organic group having 1 to 6 carbon atoms containing a fluorine atom, or a phenyl group, and at least one of R1 to R4 represents a group other than a hydrogen atom in the above definition.)

[0058]

[0059] (In the formulas (Xa-1) and (Xa-2), x and y are each independently a single bond, -O-, -C(=O)-, -C(=O)-O-, -O-C(=O)-, an alkanediyl group having 1 to 10 carbon atoms, 1,4-phenylene, -S(=O)2-, or -C(=O)-NR- (R is a hydrogen atom or a methyl group). J and k are 0 or 1. When there are a plurality of y's, they may be the same or different from each other.)

[0060]

[0061] Specific examples of the alkyl group having 1 to 6 carbon atoms among R1 to R4 in the above formula (X-1) include: methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, and the like.)

[0062] Specific examples of the alkenyl group having 2 to 6 carbon atoms among R1 to R4 include: vinyl, propenyl, butenyl, etc., and these groups may be linear or branched.)

[0063] Specific examples of the alkynyl group having 2 to 6 carbon atoms among R1 to R4 include: ethynyl, 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, 3-butynyl, and the like.)

[0064] Specific examples of the monovalent organic group having 1 to 6 carbon atoms containing a fluorine atom among R1 to R4 include: fluoromethyl, trifluoromethyl, trifluoromethoxy, 2,2,2-trifluoroethyl, 2,2,2-trifluoroethoxy, pentafluoroethyl, pentafluoropropyl, and the like.)

[0065] In the above formula (x-1), a structure selected from the group consisting of the following formulas (x1-1) to (x1-5) is preferably used.)

[0066]

[0067] The tetravalent organic group represented by the above formula (Xa-1) or (Xa-2) may be a structure represented by any of the following formulas (Xa-3) to (Xa-19).)

[0068]

[0069]

[0070] From the viewpoint of appropriately obtaining the effects of the present invention, the above polymer (A) may be at least one polymer selected from the group consisting of a polyimide precursor having a repeating unit (a1) represented by the above formula (1) and further having a repeating unit (a2) represented by the following formula (2), and a polyimide which is an imidized product of the polyimide precursor. It should be noted that the repeating unit (a2) may be composed of one or more than two repeating units.

[0071]

[0072] In the above formula (2), R and Z have the same meanings as in the above formula (1).

[0073] X2 represents a tetravalent organic group. Y2 represents a divalent organic group other than the above divalent organic group (Y1).

[0074] Specific examples of the divalent organic group other than the above divalent organic group (Y1) include divalent organic groups derived from other diamines (2) than a diamine having a structure of -N(Z)-(divalent organic group (Y1))-N(Z)- (the definitions of the divalent organic group (Y1) and Z are the same as above) (hereinafter, also referred to as specific diamine (1)).

[0075] It should be noted that the divalent organic group derived from other diamines (2) means an organic group existing between two amino groups of the diamine.

[0076] Specific examples of the above other diamines (2) include, for example, diamine H-N(Z)-Y2-N(Z)-H (Y2 and Z each represent the above definitions).

[0077] As the other diamines (2) providing Y2 in the above formula (2), the following preferred specific examples are listed, but are not limited thereto.

[0078] p-Phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, m-phenylenediamine, 2,4-dimethyl-m-phenylenediamine, 2,5-diaminotoluene, 2,6-diaminotoluene, and other phenylenediamines and their derivatives; 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dihydroxy-4,4'-diaminobiphenyl, 2,2'-difluoro-4,4'-diaminobiphenyl, 3,3'-difluoro-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 3,3'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 3,4'-diaminobiphenyl, 4,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 2,2'-diaminobiphenyl, or 2,3'-diaminobiphenyl, and other diaminobiphenyls and their derivatives; diamines represented by the following formula (d AL ), (preferably those represented by the following formula (d AL ) to (d AL-12), 1,7-bis(4-aminophenoxy)heptane, 1,7-bis(3-aminophenoxy)heptane, 1,8-bis(4-aminophenoxy)octane, 1,8-bis(3-aminophenoxy)octane, 1,9-bis(4-aminophenoxy)nonane, 1,9-bis(3-aminophenoxy)nonane, 1,10-bis(4-aminophenoxy)decane, 1,10-bis(3-aminophenoxy)decane, 1,11-bis(4-aminophenoxy)undecane, 1,11-bis(3-aminophenoxy)undecane, 1,12-bis(4-aminophenoxy)dodecane, 1,12-bis(3-aminophenoxy)dodecane, 1,2-bis(6-amino-2-naphthyloxy)ethane, 1,2-bis(6-amino-2-naphthyl)ethane, or 6-[2-(4-aminophenoxy)ethoxy]-2-naphthylamine. (Excluding the above specific diamines (1) and specific diamines (1')), 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-bis(4-aminophenoxy)diphenyl ether, 1,4-bis[4-(4-aminophenoxy)phenoxy]benzene; diamines having a pyromellitic diimide structure such as N,N'-bis(4-aminophenyl)-cyclobutane-(1,2,3,4)-tetracarboxylic diimide, N,N'-bis(4-aminophenyl)-1,3-dimethylcyclobutane-(1,2,3,4)-tetracarboxylic diimide, N,N'-bis(2,2'-bis(trifluoromethyl)-4'-amino-1,1'-biphenyl-4-yl)-cyclobutane-(1,2,3,4)-tetracarboxylic diimide; diamines having a photo-orienting group such as diamines represented by the following formulas (g-1) to (g-9); diamines having a photopolymerizable group at the terminal such as 2-(2,4-diaminophenoxy)ethyl methacrylate or 2,4-diamino-N,N-diallylaniline; diamines having a radical polymerization initiator function such as 1-(4-(2-(2,4-diaminophenoxy)ethoxy)phenyl)-2-hydroxy-2-methylpropanone, 2-(4-(2-hydroxy-2-methylpropanoyl)phenoxy)ethyl 3,5-diaminobenzoate; diamines having a urea bond such as diamines represented by the following formulas (u-1) to (u-3) (wherein the diamine does not have a carbamate-based protecting group in the molecule); diamines having an amide bond such as diamines represented by the following formulas (u-4) to (u-7) (wherein the diamine does not have a carbamate-based protecting group in the molecule);4,4'-Diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2-bis(4-aminophenyl)hexafluoropropane, 2,2-bis(3-aminophenyl)hexafluoropropane, 2,2-bis(3-amino-4-methylphenyl)hexafluoropropane, 2,2-bis(4-aminophenyl)propane, 2,2-bis(3-aminophenyl)propane, 2,2-bis(3-amino-4-methylphenyl)propane, 4,4'-diaminobenzophenone, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 1,4-bis(4-aminobenzyl)benzene; 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, 1,4-bis(4-aminophenyl)-piperazine, 3,6-diaminoacridine, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N-[3-(1H-imidazol-1-yl)propyl]-3,5-diaminobenzamide, 4-[4-[(4-aminophenoxy)methyl]-4,5-dihydro-4-methyl-2-oxazolyl]-aniline or a heterocyclic diamine such as a diamine represented by the following formula (z-1) to formula (z-13) or a diamine having a diphenylamine structure such as 4,4'-diaminodiphenylamine, 4,4'-diaminodiphenyl-N-methylamine, N,N'-bis(4-aminophenyl)-benzidine, N,N'-bis(4-aminophenyl)-N,N'-dimethylbenzidine or N,N'-bis(4-aminophenyl)-N,N'-dimethyl-1,4-benzenediamine, which has at least one nitrogen atom-containing structure selected from the group consisting of a nitrogen atom-containing heterocycle, a secondary amino group and a tertiary amino group (hereinafter, also referred to as a specific nitrogen atom-containing structure. In this case, the specific nitrogen atom-containing structure is a functional group other than the two amino groups participating in the polycondensation reaction); 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6-diaminoresorcinol, 4,4'-diamino-3,3'-dihydroxybiphenyl;Diamines having a carboxyl group such as 2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, 3,5-diaminobenzoic acid, 4,4'-diaminobiphenyl-3-carboxylic acid, 4,4'-diaminodiphenylmethane-3-carboxylic acid, 1,2-bis(4-aminophenyl)ethane-3-carboxylic acid, 4,4'-diaminobiphenyl-3,3'-dicarboxylic acid, 4,4'-diaminobiphenyl-2,2'-dicarboxylic acid, 3,3'-diaminobiphenyl-4,4'-dicarboxylic acid, 3,3'-diaminobiphenyl-2,4'-dicarboxylic acid, 4,4'-diaminodiphenylmethane-3,3'-dicarboxylic acid, 1,2-bis(4-aminophenyl)ethane-3,3'-dicarboxylic acid, or 4,4'-diaminodiphenyl ether-3,3'-dicarboxylic acid; semi-aromatic diamines having a primary amino group and a secondary amino group (preferably 4-(2-(methylamino)ethyl)aniline) (wherein, the semi-aromatic diamine refers to a diamine in which one amino group is bonded to an aromatic ring and the other amino group is not bonded to an aromatic ring); semi-aromatic diamines having two primary amino groups (preferably 4-(2-aminoethyl)aniline, or 2-(6-amino-2-naphthyl)ethylamine); 1-(4-aminophenyl)-1,3,3-trimethyl-1H-indan-5-amine, 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-indene-6-amine; diamines having a group "-N(D)-" (D represents a protecting group that is removed by heating and replaced with a hydrogen atom, preferably a carbamate-based protecting group, more preferably Boc) such as the following formulas (5-1) to (5-6), cholesteryloxy-3,5-diaminobenzene, cholestenyloxy-3,5-diaminobenzene, cholesteryloxy-2,4-diaminobenzene, cholesteryl 3,5-diaminobenzoate, cholestenyl 3,5-diaminobenzoate, lanosteryl 3,5-diaminobenzoate, and 3,6-bis(4-aminobenzoyloxy)cholestane and other diamines having a steroid skeleton, diamines represented by the following formulas (V-1) to (V-2); diamines having a siloxane bond such as 1,3-bis(3-aminopropyl)-tetramethyldisiloxane; m-xylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 1,3-bis(aminomethyl)cyclohexane, 1,4-diaminocyclohexane, 4,4'-methylenebis(cyclohexylamine), diamines formed by bonding two amino groups to a group represented by any one of the formulas (Y-1) to (Y-167) described in WO2018 / 117239, etc.;

[0079]

[0080] (Ar1 and Ar 1’ each represent a benzene ring, a biphenyl structure, or a naphthalene ring, and one or more hydrogen atoms on the benzene ring, the biphenyl structure, or the naphthalene ring are optionally substituted with a monovalent group. L1 and L 1’Each represents a single bond, -O-, -C(=O)- or -O-C(=O)-. A represents -CH2-, an alkylene group having 2 to 12 carbon atoms, or a divalent organic group in which at least any one of -O-, -C(=O)-O- and -O-C(=O)- is inserted between the carbon-carbon bonds of the alkylene group. Any hydrogen atom of A is optionally substituted with a halogen atom.

[0081] One or more hydrogen atoms on the above-mentioned benzene ring, biphenyl structure or naphthalene ring are optionally substituted with a monovalent group. Examples of the monovalent group include: halogen atom, alkyl group having 1 to 3 carbon atoms, alkenyl group having 2 to 3 carbon atoms, alkoxy group having 1 to 3 carbon atoms, fluoroalkyl group having 1 to 3 carbon atoms, fluoroalkenyl group having 2 to 3 carbon atoms, fluoroalkoxy group having 1 to 3 carbon atoms, alkyloxycarbonyl group having 2 to 3 carbon atoms, cyano group, nitro group, etc.)

[0082]

[0083] (In formula (d AL -4), when the bonding positions of the amino group and the oxygen atom on each benzene ring are at the 1,4-positions, one or two methyl groups are each bonded meta to one or two amino groups.

[0084] In formula (d AL -5), when the bonding positions of the amino group and the oxygen atom on each benzene ring are at the 1,4-positions, one or two fluorine atoms are each bonded meta to one or two amino groups.

[0085] In formula (d AL -6), the sum of m1, m2 and n is 1 to 12. In formula (d AL -8), the sum of m1, m2 and n is 3 to 12.

[0086] In formula (d AL -11) and (d AL -12), the sum of m1, m2 and n is 3 to 12.)

[0087]

[0088]

[0089]

[0090] (In the above formula (V-1), m and n are integers from 0 to 3, satisfying 1 ≤ m + n ≤ 4. j is an integer of 0 or 1. X 1 represents -(CH2) a-(where a is an integer from 1 to 15), -CONH-, -NHCO-, -CO-N(CH3)-, -NH-, -O-, -CH2O-, -CH2-OCO-, -COO- or -OCO-.

[0091] R 1 represents a monovalent group such as a fluorine atom, a fluorine atom-containing alkyl group having 1 to 10 carbon atoms, a fluorine atom-containing alkoxy group having 1 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, and an alkoxyalkyl group having 2 to 10 carbon atoms.

[0092] In the above formula (V-2), X 2 represents -O-, -CH2O-, -CH2-OCO-, -COO- or -OCO-. In the case where there are two m, n, X 1 , R 1 , they each independently have the above definitions.)

[0093] From the viewpoint of appropriately obtaining the effects of the present invention, the polymer (A) is preferably at least one polymer selected from the group consisting of a polyimide precursor and a polyimide which is an imidized product of the polyimide precursor, the polyimide precursor containing a repeating unit in which Y2 is a divalent organic group derived from a diamine, and the diamine being: phenylenediamine and its derivatives, biphenylenediamine and its derivatives, the diamine represented by the above formula (d AL ), the diamine having a tetracarboxylic diimide structure, the diamine having a photo-orienting group, the diamine having a urea bond, the diamine having an amide bond, the diamine having a nitrogen atom-containing structure, the semi-aromatic diamine having a primary amino group and a secondary amino group, the semi-aromatic diamine having two primary amino groups, or the diamine having the group "-N(D)-".

[0094] From the viewpoint of appropriately obtaining the effects of the present invention, for the polymer (A), the total of the repeating unit (a1) and the imidized structural unit of the repeating unit (a1) is preferably 5 to 100 mol%, more preferably 10 to 100 mol%, of all the repeating units possessed by the polymer (A).

[0095] It should be noted that in the total here, the case where either the repeating unit (a1) or the imidized structural unit of the repeating unit (a1) is 0 mol% is also included. In the following cases where it is also referred to as the total, the case where one or more of the constituent elements is 0 mol% is also included.

[0096] In the case where the polymer (A) contains repeating units other than the repeating unit (a1) and / or the imidized structural unit of the repeating unit (a1), it is preferable that the total of the repeating unit (a1) and the imidized structural unit of the repeating unit (a1) is 95 mol% or less, more preferably 90 mol% or less, of all the repeating units possessed by the polymer (A).

[0097] Regarding the polymer (A), the total of the repeating unit (a1) and the imidized structural unit of the repeating unit (a1) is preferably 95 mol% or less, more preferably 90 mol%, and further preferably 80 mol% or less, of all the repeating units possessed by the polymer (A).

[0098] From the viewpoint of appropriately obtaining the effects of the present invention, regarding the polymer (A), the total of the repeating unit (a2) and the imidized structural unit of the repeating unit (a2) is preferably 5 mol% or more, more preferably 10 mol% or more, of all the repeating units possessed by the polymer (A).

[0099] In addition, regarding the polymer (A), the total of the repeating unit (a2) and the imidized structural unit of the repeating unit (a2) is preferably 95 mol% or less, more preferably 90 mol% or less, of all the repeating units possessed by the polymer (A).

[0100] <Polymer (A’)>

[0101] One aspect of the liquid crystal aligning agent of the present invention contains at least one polymer (A’) selected from the group consisting of a polyimide precursor having a repeating unit (a1’) represented by the following formula (1’) and a polyimide which is an imidized product of the polyimide precursor. It should be noted that the polymer (A’) may be composed of one kind or two or more kinds of polymers. In addition, the repeating units constituting the polymer (A’) may be one kind of repeating unit or two or more different repeating units.

[0102]

[0103] (X 1’ represents a tetravalent organic group selected from the above formulas (X-1) to (X-9).

[0104] R 1’ and R 2’ each independently represent a hydrogen atom, a fluorine atom or a monovalent organic group having 1 carbon atom, and at least one R 1’ represents a fluorine atom or a monovalent organic group having 1 carbon atom.

[0105] L’ represents an alkylene group having 1 to 12 carbon atoms, a cyclohexylene group, a phenylene group, a biphenyl structure or a naphthylene group.

[0106] R’ and Z’ each independently represent a hydrogen atom or a monovalent organic group.

[0107] Multiple Rs 1’ , R 2’ , R’, and Z’ each independently have the above definitions.

[0108] X in the above formula (1’) 1’ represents a tetravalent organic group selected from the above formulas (X-1) to (X-9), and at this time, they are tetravalent tetracarboxylic acid residues of specific tetracarboxylic dianhydrides or derivatives derived from these specific tetracarboxylic dianhydrides (they can also be collectively referred to as specific tetracarboxylic acids (1’)).

[0109] As specific examples of the monovalent organic groups in R’ and Z’ in the above formula (1’), the structures exemplified by the monovalent organic groups in R and Z in the above formula (1) can be cited.

[0110] The preferred embodiments of R’ and Z’ in the above formula (1’) are the same as the preferred embodiments of R and Z in the above formula (1).

[0111] R in the above formula (1’) 1’ In the benzene ring to which R 1’ is bonded, it is bonded adjacent to the bonding position of -N(Z’)-. At least one fluorine atom or a monovalent organic group having 1 carbon atom (R 1’ ) is bonded adjacent to the bonding position of -N(Z’)-. Therefore, compared with the case of bonding to the meta-position or para-position, the desired effect of the present invention of being able to suppress AC afterimages at a higher level than before can be obtained.

[0112] As the monovalent organic group having 1 carbon atom in R 1’ in the above formula (1’), examples include: methyl, methoxy, trifluoromethyl, cyano, etc.

[0113] At least one of R 1’ in the above formula (1’) is preferably methyl or methoxy.

[0114] At least two of R 1’ in the above formula (1’) can be fluorine atoms or monovalent organic groups having 1 carbon atom.

[0115] L’ in the above formula (1’) is preferably an alkylene group having 1 to 12 carbon atoms, can be an alkylene group having 2 carbon atoms, can be an alkylene group having 1 to 2 carbon atoms, or can be an alkylene group having 3 to 12 carbon atoms.

[0116] R in the above formula (1) 2’ In the benzene ring to which R 2’ is bonded, it is bonded meta to the bonding position of -N(Z’)-. R2’ each independently represents a hydrogen atom, a fluorine atom or a monovalent organic group having 1 carbon atom, R 1’ at least one of which represents a fluorine atom or a monovalent organic group having 1 carbon atom. From the viewpoint of appropriately obtaining the effects of the present invention, it is preferable that all R 2’ are hydrogen atoms. When all R 2’ are hydrogen atoms, the formula (1') is represented by the following formula (1'-1).

[0117]

[0118] (In the above formula (1'-1), R 1’ , R', L' and Z' have the same definitions as in the above formula (1').

[0119] As a preferred specific example of the divalent organic group *-(benzene ring substituted by two R 1’ and two R 2’ )-O-L'-O-(benzene ring substituted by two R 1’ and two R 2’ )-*(hereinafter, also referred to as divalent organic group (Y 1’ )) in the above formula (1'), the structures of the following formulas (Y1'-1) to (Y1'-3) can be cited.

[0120]

[0121] From the viewpoint of appropriately obtaining the effects of the present invention, the above polymer (A') can be at least one polymer selected from the group consisting of a polyimide precursor having a repeating unit (a1') represented by the above formula (1') and further having a repeating unit (a2') represented by the following formula (2') and a polyimide which is an imidized product of the polyimide precursor. It should be noted that the repeating unit (a2') can be composed of one or two or more repeating units.

[0122]

[0123] In the above formula (2'), R' has the same meaning as R' in the above formula (1'), and Z' has the same meaning as Z' in the above formula (1').

[0124] X 2’ represents a tetravalent organic group, Y 2’ represents a divalent organic group, and satisfies any one of the following conditions (i) or (ii).

[0125] (i) When Y 2’ represents the above divalent organic group (Y 1’ ), X 2’represents a tetravalent organic group selected from the tetravalent organic groups represented by the above formulas (X-10) to (X-27), or a tetravalent tetracarboxylic acid residue derived from an aromatic tetracarboxylic dianhydride or a derivative thereof (preferably the tetravalent organic group of any one of the above formulas (Xa-1) to (Xa-2) or the above formulas (Xr-1) to (Xr-7)).

[0126] (ii) In Y 2’ represents a divalent organic group other than the above divalent organic group (Y 1’ ), X 2’ represents a tetravalent organic group.

[0127] As the tetravalent organic group of X in the above (ii) 2’ , specific examples of the tetravalent organic group include the tetravalent organic group exemplified by X1 in the above formula (1).

[0128] As the divalent organic group other than the divalent organic group (Y 1’ ) in the above (ii), for example, there can be mentioned a divalent organic group derived from a diamine other than a diamine having a structure of -N(Z')-(divalent organic group (Y 1’ ))-N(Z')- (the definitions of the divalent organic group (Y 1’ ) and Z' are the same as those defined above) (hereinafter, also referred to as a specific diamine (1')).

[0129] It should be noted that the divalent organic group derived from the other diamine (2') refers to the organic group existing between the two amino groups of the diamine.

[0130] Regarding the other diamine (2'), for example, the diamine can be represented by H-N(Z')-Y 2’ -N(Z')-H (Z' each represents the above definition, and Y 2’ represents a divalent organic group other than the divalent organic group (Y 1’ )).

[0131] As a preferred specific example of the above other diamine (2'), for example, there can be mentioned a compound exemplified by the specific example of the above other diamine (2).

[0132] From the viewpoint of appropriately obtaining the effects of the present invention, the polymer (A') is preferably at least one polymer selected from the group consisting of a polyimide precursor and a polyimide which is an imidized product of the polyimide precursor, and the polyimide precursor contains a repeating unit in which the above Y 2’ is a divalent organic group derived from a diamine, and the diamine is: phenylenediamine and its derivatives, biphenylenediamine and its derivatives, and the above formula (d ALThe diamines represented, the diamines having a tetracarboxylic diimide structure, the diamines having a photo-orienting group, the diamines having a urea bond, the diamines having an amide bond, the diamines having a nitrogen atom-containing structure, the semi-aromatic diamines having a primary amino group and a secondary amino group, the semi-aromatic diamines having two primary amino groups, or the diamines having the group “-N(D)-”.

[0133] From the viewpoint of appropriately obtaining the effects of the present invention, for the polymer (A'), the total of the repeating unit (a1') and the imidized structural unit of the repeating unit (a1') is preferably 5 to 100 mol% of all the repeating units possessed by the polymer (A'), more preferably 10 to 100 mol%.

[0134] It should be noted that in the total here, the case where either the repeating unit (a1') or the imidized structural unit of the repeating unit (a1') is 0 mol% is also included. In the following cases where it is also referred to as the total, the case where one or more of the constituent elements is 0 mol% is also included.

[0135] When the polymer (A') contains repeating units other than the repeating unit (a1') and / or the imidized structural unit of the repeating unit (a1'), it is preferable that the total of the repeating unit (a1') and the imidized structural unit of the repeating unit (a1') is 95 mol% or less, more preferably 90 mol% or less, of all the repeating units possessed by the polymer (A').

[0136] For the polymer (A'), the total of the repeating unit (a1') and the imidized structural unit of the repeating unit (a1') is preferably 95 mol% or less, more preferably 90 mol%, further preferably 80 mol% or less, of all the repeating units possessed by the polymer (A').

[0137] From the viewpoint of appropriately obtaining the effects of the present invention, for the polymer (A'), the total of the repeating unit (a2') and the imidized structural unit of the repeating unit (a2') is preferably 5 mol% or more, more preferably 10 mol% or more, of all the repeating units possessed by the polymer (A').

[0138] In addition, for the polymer (A'), the total of the repeating unit (a2') and the imidized structural unit of the repeating unit (a2') is preferably 95 mol% or less, more preferably 90 mol% or less, of all the repeating units possessed by the polymer (A').

[0139] <Polymer (B)>

[0140] The liquid crystal aligning agent of the present invention may have at least one polymer (B) selected from the group consisting of a polyimide precursor and a polyimide which is an imidized product of the polyimide precursor, different from the above-mentioned polymer (A) or polymer (A').

[0141] As the polymer (B), for example, at least one polymer selected from the group consisting of a polyimide precursor that does not have the above-mentioned repeating unit (a1) or the above-mentioned repeating unit (a1') in the molecule and a polyimide which is an imidized product of the polyimide precursor can be cited. It should be noted that the polymer (B) may be composed of one or two or more polymers.

[0142] From the viewpoint of appropriately obtaining the effects of the present invention, as the polymer (B), a polymer having at least one repeating unit selected from the group consisting of a repeating unit (b1) represented by the following formula (3) and an imidized structural unit of the repeating unit (b1) can be cited, and a polyamic acid having a repeating unit (b1) represented by the following formula (3) can be more preferably used. In addition, the repeating units constituting the polymer (B) may be one or two or more.

[0143]

[0144] In the above formula (3), X3 is a tetravalent organic group, and Y3 is a divalent organic group. R has the same meaning as R in the above formula (1), and Z has the same meaning as Z in the above formula (1). However, the above formula (3) is different from the above formula (1) and the above formula (1').

[0145] As the tetravalent organic group in the above X3, a tetravalent organic group derived from an aliphatic tetracarboxylic dianhydride, a tetravalent organic group derived from an alicyclic tetracarboxylic dianhydride, or a tetravalent organic group derived from an aromatic tetracarboxylic dianhydride can be cited.

[0146] Specific examples of the tetravalent organic group in X3 are the tetravalent organic groups exemplified by the above X1. From the viewpoint of appropriately obtaining the effects of the present invention, for the above-mentioned aliphatic or alicyclic tetracarboxylic dianhydride, from the viewpoint of improving the liquid crystal alignment property, a tetracarboxylic dianhydride having at least one partial structure selected from the group consisting of a cyclobutane ring structure, a cyclopentane ring structure, and a cyclohexane ring structure is preferred.

[0147] More preferably, X3 is a tetravalent organic group represented by any one of the above formulas (X-1) to (X-27), a tetravalent organic group represented by the above formulas (Xa-1) to (Xa-2), or a tetravalent organic group represented by the above formulas (Xr-1) to (Xr-7) (they are also collectively referred to as specific tetravalent organic groups).

[0148] From the viewpoint of appropriately achieving the effects of the present invention, with respect to the polymer (B), it is preferable to contain, in an amount of 5 mol% or more of all the repeating units contained in the polymer (B), a repeating unit in which X3 is the specific tetravalent organic group described above, and more preferably to contain the repeating unit in an amount of 10 mol% or more of all the repeating units contained in the polymer (B).

[0149] Examples of the divalent organic group in Y3 include divalent organic groups derived from the other diamine (2') described above. From the viewpoint of having less residual DC ghosting, the polymer (B) is preferably at least one polymer selected from the group consisting of a polyimide precursor and a polyimide which is an imidized product of the polyimide precursor, the polyimide precursor containing a repeating unit in which Y3 is a divalent organic group derived from a diamine (collectively also referred to as a specific divalent organic group (b)), the diamine being: phenylenediamine and its derivatives, biphenylenediamine and its derivatives, the diamine represented by the above formula (d AL )), the above diamine having a urea bond, the above diamine having an amide bond, the above diamine having a nitrogen atom-containing structure, 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6-diaminoresorcinol, the above diamine having a carboxyl group, the above semi-aromatic diamine having a primary amino group and a secondary amino group or a semi-aromatic diamine having two primary amino groups.

[0150] From the viewpoint of improving the transmittance, the polymer (B) preferably has two or more repeating units represented by the above formula (3). Further, from the viewpoint of improving the transmittance, the polymer (B) more preferably contains a repeating unit having a divalent organic group in which Y3 is derived from the above diamine having a urea bond, the above diamine having an amide bond, or the above diamine having a nitrogen atom-containing structure, and a repeating unit having a divalent organic group in which Y3 is derived from a diamine other than these.

[0151] From the viewpoint of having less residual DC ghosting, with respect to the polymer (B), it contains, in an amount of 1 mol% or more of all the repeating units contained in the polymer (B), a repeating unit in which Y3 is the specific divalent organic group (b) described above, preferably contains the repeating unit in an amount of 5 mol% or more of all the repeating units contained in the polymer (B), more preferably contains the repeating unit in an amount of 10 mol% or more of all the repeating units contained in the polymer (B), and still more preferably contains the repeating unit in an amount of 20 mol% or more of all the repeating units contained in the polymer (B).

[0152] From the viewpoint of having less residual DC ghosting, the mass ratio of the content of the polymer (A) to the content of the polymer (B) (content of the polymer (A) / content of the polymer (B)) is preferably 10 / 90 to 90 / 10, more preferably 20 / 80 to 90 / 10, and still more preferably 20 / 80 to 80 / 20.

[0153] From the viewpoint of less afterimage derived from residual DC, the mass ratio of the content of polymer (A') to the content of polymer (B) (content of polymer (A') / content of polymer (B)) is preferably 10 / 90 to 90 / 10, more preferably 20 / 80 to 90 / 10, and further preferably 20 / 80 to 80 / 20.

[0154] <Manufacturing methods of polymer (A), polymer (A'), and polymer (B)>

[0155] In the present invention, polyimide precursors (such as polyamide acid esters and polyamic acids) in polymer (A), polymer (A'), and polymer (B), and polyimides which are imidized products of these polyimide precursors can be synthesized, for example, by known methods described in WO2013 / 157586.

[0156] Specifically, it is synthesized by reacting a diamine component and a tetracarboxylic acid derivative component in a solvent (polycondensation). Examples of the above-mentioned tetracarboxylic acid derivative component include tetracarboxylic dianhydrides or their derivatives (tetracarboxylic dihalides, tetracarboxylic diesters, or tetracarboxylic diester dihalides). When an amic acid structure is included in a part of polymer (A), polymer (A'), or polymer (B), for example, by reacting a tetracarboxylic dianhydride component and a diamine component, a polymer having an amic acid structure (polyamic acid) can be obtained. The solvent is not particularly limited as long as the generated polymer is soluble in it.

[0157] Specific examples are listed. The diamine component and the tetracarboxylic acid derivative component for obtaining the polyimide precursor of polymer (A) are each selected and used in such a way as to obtain the structure of the repeating unit represented by the above formulas (1) and (2) possessed by polymer (A).

[0158] For example, when having the repeating unit represented by formula (1) possessed by polymer (A), as the diamine component, a specific diamine (1) is used, and in addition, as the tetracarboxylic acid derivative component, a tetracarboxylic acid derivative having the above structure of X1 is used.

[0159] Specific examples of the above solvent when reacting the diamine component and the tetracarboxylic acid derivative component include: N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, 1,3-dimethyl-2-imidazolidinone. In addition, when the solvent solubility of the polymer is high, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, and H3C-CH(OH)-CH2-O-D 1 (D1 (wherein the alkyl group has 1 to 3 carbon atoms), HO-CH2-CH2-O-D 2 (D 2 (wherein the alkyl group has 1 to 3 carbon atoms) or HO-CH2-CH2-O-CH2-CH2-O-D 3 (D 3 (wherein the alkyl group has 1 to 4 carbon atoms).

[0160] As the solvents represented by H3C-CH(OH)-CH2-O-D 1 , HO-CH2-CH2-O-D 2 , HO-CH2-CH2-O-CH2-CH2-O-D 3 Specific examples include: propylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, etc.

[0161] These solvents can be used alone or in combination. Moreover, even solvents that do not dissolve the polymer can be used in combination with the above solvents within the range where the formed polymer does not precipitate.

[0162] When reacting the diamine component and the tetracarboxylic acid derivative component in a solvent, the reaction can be carried out at any concentration. The solvent is preferably 1 to 50% by mass, more preferably 5 to 30% by mass. Alternatively, the reaction can be carried out at a high concentration initially and then additional solvent can be added.

[0163] In the reaction, the ratio of the total molar amount of the diamine component to the total molar amount of the tetracarboxylic acid derivative component (total molar amount of tetracarboxylic acid derivative component / total molar amount of diamine component) is preferably 0.8 to 1.2. Similar to a typical polycondensation reaction, the closer this molar ratio is to 1.0, the larger the molecular weight of the resulting polymers (A), (A'), and (B).

[0164] Polyamide acid esters can be obtained, for example, by the following known methods:

[0165] [I] A method of reacting the polyamic acid obtained by the above method with an esterifying agent.

[0166] [II] A method of reacting a tetracarboxylic acid diester with a diamine.

[0167] [III] A method of reacting a tetracarboxylic acid diester dihalide with a diamine, etc.

[0168] As methods for obtaining polyimide, examples include: thermal imidization by heating a solution containing polyimide precursors such as the polyamic acid and polyamide acid ester obtained in the above reaction, or catalytic imidization by adding a catalyst to the above solution.

[0169] In the polyimide of the polymer (A), polymer (A'), and polymer (B) of the present invention, part or all of the repeating units of the polyimide precursor are cyclized. In the above polyimide, the imidization rate is preferably 20 to 95%, more preferably 30 to 95%, and still more preferably 50 to 95%.

[0170] <Solution viscosity and molecular weight of polymer>

[0171] When a solution of the polyimide precursor and polyimide in the polymer (A), polymer (A'), and polymer (B) of the present invention is prepared at a concentration of 10 to 15% by mass, for example, from the viewpoint of workability, it is preferably maintained at a solution viscosity of 10 to 1000 mPa·s, but there is no particular limitation. It should be noted that the solution viscosity (mPa·s) of the above polymer is the value measured at 25°C using an E-type rotational viscometer for a polymer solution prepared at a concentration of 10 to 15% by mass using a good solvent for the polymer (for example, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.).

[0172] The polystyrene-reduced weight-average molecular weight (Mw) of the above polyimide precursor and polyimide measured by gel permeation chromatography (GPC) is preferably 1000 to 500000, more preferably 2000 to 300000. In addition, the molecular weight distribution (Mw / Mn) represented by the ratio of Mw to the polystyrene-reduced number-average molecular weight (Mn) measured by GPC is preferably 15 or less, more preferably 10 or less. By being within this molecular weight range, good alignment and stability of the liquid crystal display element can be ensured.

[0173] <End-capping agent>

[0174] When synthesizing the polymer (A), polymer (A'), and polymer (B) in the present invention, an appropriate end-capping agent can also be used together with the above-mentioned tetracarboxylic acid derivative component and diamine component to synthesize a capped polymer. The capped polymer has the effects of improving the film hardness of the liquid crystal alignment film obtained from the coating film and improving the adhesion characteristics between the sealant and the liquid crystal alignment film.

[0175] Examples of the ends of the polymer (A), polymer (A'), and polymer (B) in the present invention include: amino group, carboxyl group, acid anhydride group, or their derivatives. The amino group, carboxyl group, acid anhydride group, and isocyanate group can be obtained by ordinary condensation reactions or by end-capping using the following end-capping agents. For example, they can be obtained in the same way by using the following end-capping agents.

[0176] Examples of the capping agent include acid anhydrides such as acetic anhydride, maleic anhydride, nadic anhydride, phthalic anhydride, itaconic anhydride, cyclohexanedicarboxylic anhydride, 3-hydroxyphthalic anhydride, trimellitic anhydride, 3-(3-trimethoxysilyl)propyl-3,4-dihydrofuran-2,5-dione, 4,5,6,7-tetrafluoroisobenzofuran-1,3-dione, 4-ethynylphthalic anhydride; dicarbonate diester compounds such as di-tert-butyl dicarbonate, diallyl dicarbonate; chlorocarbonyl compounds such as acryloyl chloride, methacryloyl chloride, nicotinoyl chloride; monoamine compounds such as aniline, 2-aminophenol, 3-aminophenol, 4-aminosalicylic acid, 5-aminosalicylic acid, 6-aminosalicylic acid, 2-aminobenzoic acid, 3-aminobenzoic acid, 4-aminobenzoic acid, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine; monoisocyanate compounds such as isocyanates having an unsaturated bond such as ethyl isocyanate, phenyl isocyanate, naphthyl isocyanate, 2-acryloyloxyethyl isocyanate, 2-methacryloyloxyethyl isocyanate; isothiocyanate compounds such as ethyl isothiocyanate, allyl isothiocyanate, etc.

[0177] The usage ratio of the capping agent is preferably 0.01 to 20 mol parts, more preferably 0.01 to 10 mol parts, relative to 100 mol parts in total of the diamine components used.

[0178] <Liquid crystal aligning agent>

[0179] The liquid crystal aligning agent of the present invention contains polymer (A), polymer (A') and, if necessary, polymer (B). In addition to containing polymer (A), polymer (A') and polymer (B), the liquid crystal aligning agent of the present invention may also contain other polymers. Specific examples of other polymers include polymers selected from the group consisting of polysiloxane, polyester, polyamide, polyurea, polyurethane, polyorganosiloxane, cellulose derivative, polyacetal, polystyrene derivative, poly(styrene-maleic anhydride) copolymer, poly(isobutylene-maleic anhydride) copolymer, poly(vinyl ether-maleic anhydride) copolymer, poly(styrene-phenylmaleimide) derivative, poly(meth)acrylate.

[0180] As specific examples of the poly(styrene - maleic anhydride) copolymer, the following can be cited: SMA1000, 2000, 3000 (manufactured by Cray Valley), GSM301 (manufactured by Gifu Shellac Manufacturing), etc. As specific examples of the poly(isobutylene - maleic anhydride) copolymer, ISOBAM - 600 (manufactured by Kuraray) can be cited. As specific examples of the poly(vinyl ether - maleic anhydride) copolymer, Gantrez AN - 139 (methyl vinyl ether maleic anhydride resin, manufactured by Ashland) can be cited. Other polymers can be used alone or two or more thereof can be used in combination.

[0181] The content ratio of other polymers is preferably 90 parts by mass or less, more preferably 80 parts by mass or less, and still more preferably 50 parts by mass or less, relative to 100 parts by mass in total of the polymers contained in the liquid crystal aligning agent. In addition, it is preferably 0.1 part by mass or more, and more preferably 1 part by mass or more.

[0182] The liquid crystal aligning agent is used to form a liquid crystal alignment film, and in view of forming a uniform thin film, it is in the form of a coating solution. In the liquid crystal aligning agent of the present invention, a coating solution containing the above polymer component and an organic solvent is also preferred. At this time, the concentration of the polymer in the liquid crystal aligning agent can be appropriately changed according to the setting of the thickness of the coating film to be formed. In view of forming a uniform and defect - free coating film, the concentration of the polymer is preferably 1% by mass or more, and in view of the storage stability of the solution, the concentration of the polymer is preferably 10% by mass or less. A particularly preferred polymer concentration is 2 - 8% by mass.

[0183] From the viewpoint of appropriately obtaining the effects of the present invention, the content of each of the polymer (A), polymer (A'), and polymer (B) added as needed in the liquid crystal aligning agent is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, and still more preferably 50 parts by mass or more, relative to 100 parts by mass in total of the polymer components contained in the liquid crystal aligning agent.

[0184] When the liquid crystal aligning agent contains the above - mentioned other polymers, the content of each of the polymer (A), polymer (A'), and polymer (B) added as needed is preferably 99.9 parts by mass or less, and more preferably 99 parts by mass or less, relative to 100 parts by mass in total of the polymers contained in the liquid crystal aligning agent.

[0185] The organic solvents contained in the liquid crystal aligning agent are not particularly limited as long as they can uniformly dissolve the polymer components. Specific examples thereof include: N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethyl lactamide, N,N-dimethylpropionamide, tetramethylurea, N,N-diethylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethyl sulfoxide, γ-butyrolactone, γ-valerolactone, 1,3-dimethyl-2-imidazolidinone, methyl ethyl ketone, cyclohexanone, cyclopentanone, 3-methoxy-N,N-dimethylpropionamide, 3-butoxy-N,N-dimethylpropionamide, N-n-propyl-2-pyrrolidone, N-isopropyl-2-pyrrolidone, N-n-butyl-2-pyrrolidone, N-tert-butyl-2-pyrrolidone, N-n-pentyl-2-pyrrolidone, N-methoxypropyl-2-pyrrolidone, N-ethoxyethyl-2-pyrrolidone, N-methoxybutyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone (collectively referred to as "good solvents"). Among them, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 3-methoxy-N,N-dimethylpropionamide, 3-butoxy-N,N-dimethylpropionamide or γ-butyrolactone is preferred. The content of the good solvent is preferably 20 to 99% by mass, more preferably 20 to 90% by mass, and particularly preferably 30 to 80% by mass of the total solvents contained in the liquid crystal aligning agent.

[0186] In addition, the organic solvents contained in the liquid crystal aligning agent preferably use a mixed solvent in which, in addition to the above solvents, a solvent (also referred to as a poor solvent) that improves the coatability and the surface smoothness of the coating film when coating the liquid crystal aligning agent is used in combination. The content of the poor solvent is preferably 1 to 80% by mass, more preferably 10 to 80% by mass, and particularly preferably 20 to 70% by mass of the total solvents contained in the liquid crystal aligning agent. The type and content of the poor solvent are appropriately selected according to the coating device, coating conditions, coating environment, etc. of the liquid crystal aligning agent.

[0187] Specific examples of the above poor solvents are described below, but are not limited to these poor solvents.

[0188] Examples include: diisopropyl ether, diisobutyl ether, diisobutyl carbinol (2,6-dimethyl-4-heptanol), ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 1,2-dibutoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, 4-hydroxy-4-methyl-2-pentanone, diethylene glycol methyl ethyl ether, diethylene glycol dibutyl ether, 3-ethoxybutyl acetate, 1-methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, ethylene glycol monoacetate, ethylene glycol diacetate, propylene carbonate, ethylene carbonate, ethylene glycol monobutyl ether, ethylene glycol monoisoamyl ether, ethylene glycol monohexyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, 1-(2-butoxyethoxy)-2-propanol, 2-(2-butoxyethoxy)-1-propanol, propylene glycol monomethyl ether acetate, propylene glycol diacetate, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, ethylene glycol monobutyl ether acetate, diethylene glycol monopropyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, 2-(2-ethoxyethoxy)ethyl acetate, diethylene glycol diacetate, propylene glycol diacetate, n-butyl acetate, propylene glycol monoethyl ether acetate, cyclohexyl acetate, 4-methyl-2-pentyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, butyl 3-methoxypropionate, n-butyl lactate, isoamyl lactate, diethylene glycol monoethyl ether, diisobutyl ketone (2,6-dimethyl-4-heptanone), etc.

[0189] As a poor solvent, preferably, diisobutyl carbinol, propylene glycol monobutyl ether, propylene glycol diacetate, diethylene glycol diethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monobutyl ether, ethylene glycol monobutyl ether acetate or diisobutyl ketone.

[0190] Preferred combinations of solvents as good solvents and poor solvents include: N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether; N-methyl-2-pyrrolidone, γ-butyrolactone, and ethylene glycol monobutyl ether; N-methyl-2-pyrrolidone, γ-butyrolactone, and propylene glycol monobutyl ether; N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether; N-ethyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone; N-ethyl-2-pyrrolidone and propylene glycol diacetate; N,N-dimethyl lactamide and diisobutyl ketone; N-methyl-2-pyrrolidone and ethyl 3-ethoxypropionate; N-ethyl-2-pyrrolidone and ethyl 3-ethoxypropionate; N-methyl-2-pyrrolidone, ethyl 3-ethoxypropionate, and dipropylene glycol monomethyl ether; N-ethyl-2-pyrrolidone, ethyl 3-ethoxypropionate, and propylene glycol monobutyl ether; N-methyl-2-pyrrolidone, ethyl 3-ethoxypropionate, and diethylene glycol monopropyl ether; N-ethyl-2-pyrrolidone, ethyl 3-ethoxypropionate, and diethylene glycol monopropyl ether; N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether acetate; N-ethyl-2-pyrrolidone and dipropylene glycol dimethyl ether; N,N-dimethyl lactamide and ethylene glycol monobutyl ether; N,N-dimethyl lactamide and propylene glycol diacetate; N-ethyl-2-pyrrolidone and diethylene glycol diethyl ether; N-ethyl-2-pyrrolidone, diethylene glycol monoethyl ether, and butyl cellosolve acetate; N-methyl-2-pyrrolidone, diethylene glycol monomethyl ether, and butyl cellosolve acetate; N,N-dimethyl lactamide and diethylene glycol diethyl ether; N-methyl-2-pyrrolidone, γ-butyrolactone, 4-hydroxy-4-methyl-2-pentanone, and diethylene glycol diethyl ether; N-ethyl-2-pyrrolidone, N-methyl-2-pyrrolidone, and 4-hydroxy-4-methyl-2-pentanone; N-ethyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone, and propylene glycol monobutyl ether; N-methyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone, and diisobutyl ketone; N-methyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone, and dipropylene glycol monomethyl ether; N-methyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone, and propylene glycol monobutyl ether; N-methyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone, and propylene glycol diacetate; N-ethyl-2-pyrrolidone, 4-hydroxy-4-methyl-2-pentanone, and dipropylene glycol dimethyl ether; γ-butyrolactone, 4-hydroxy-4-methyl-2-pentanone, and diisobutyl ketone; γ-butyrolactone, 4-hydroxy-4-methyl-2-pentanone, and propylene glycol diacetate; N-methyl-2-pyrrolidone, γ-butyrolactone, propylene glycol monobutyl ether, and diisobutyl ketone; N-methyl-2-pyrrolidone, γ-butyrolactone, propylene glycol monobutyl ether, and diisopropyl ether; N-methyl-2-pyrrolidone, γ-butyrolactone, propylene glycol monobutyl ether, and diisobutyl carbinol;N-methyl-2-pyrrolidone, γ-butyrolactone and dipropylene glycol dimethyl ether; N-methyl-2-pyrrolidone, propylene glycol monobutyl ether and dipropylene glycol dimethyl ether; N-ethyl-2-pyrrolidone, propylene glycol monobutyl ether and dipropylene glycol monomethyl ether; N-ethyl-2-pyrrolidone, diethylene glycol diethyl ether and dipropylene glycol monomethyl ether; N-ethyl-2-pyrrolidone, propylene glycol monobutyl ether and propylene glycol diacetate; N-ethyl-2-pyrrolidone, propylene glycol monobutyl ether and diisobutyl ketone; N-ethyl-2-pyrrolidone, γ-butyrolactone and diisobutyl ketone; N-ethyl-2-pyrrolidone, N,N-dimethyl lactamide and diisobutyl ketone; N-methyl-2-pyrrolidone, ethylene glycol monobutyl ether and ethylene glycol monobutyl ether acetate; γ-butyrolactone, ethylene glycol monobutyl ether acetate and dipropylene glycol dimethyl ether; N-ethyl-2-pyrrolidone, ethylene glycol monobutyl ether acetate and propylene glycol dimethyl ether; N-methyl-2-pyrrolidone, 4-methyl-2-pentyl acetate and ethylene glycol monobutyl ether; N-ethyl-2-pyrrolidone, cyclohexyl acetate, diacetone alcohol cyclohexanone and propylene glycol monomethyl ether; cyclopentanone and propylene glycol monomethyl ether; N-methyl-2-pyrrolidone, cyclohexanone and propylene glycol monomethyl ether, etc.;

[0191] The liquid crystal aligning agent of the present invention may also additionally contain components other than the polymer component and the organic solvent (hereinafter, also referred to as additive components). Examples of such additive components include: adhesion aids for improving the adhesion between the liquid crystal alignment film and the substrate and between the liquid crystal alignment film and the sealant; compounds for improving the strength of the liquid crystal alignment film (hereinafter, also referred to as crosslinkable compounds); compounds for promoting imidization; dielectrics or conductive substances for adjusting the dielectric constant and resistance of the liquid crystal alignment film, etc.

[0192] As the above-mentioned adhesion aids, for example, the following can be cited: 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldiethoxymethylsilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, tris[3-(trimethoxysilyl)propyl]isocyanurate, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane and other silane coupling agents.

[0193] From the viewpoint of appropriately obtaining the effects of the present invention, when a silane coupling agent is used, it is preferably 0.1 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, based on 100 parts by mass of the polymer component contained in the liquid crystal aligning agent.

[0194] From the viewpoint of appropriately obtaining the effects of the present invention, as the above-mentioned crosslinkable compound, at least one compound selected from the group consisting of a crosslinkable compound having a substituent and a crosslinkable compound having a polymerizable unsaturated group can be cited, wherein the substituent is selected from at least one of an epoxy group, an isocyanate group, an oxetanyl group, a blocked isocyanate group, an oxazolinyl group, a cyclic carbonate group, a mesityl oxide structure, a hydroxyl group, and an alkoxy group.

[0195] As preferred specific examples of the above crosslinkable compounds, the following can be cited: ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6 - hexanediol diglycidyl ether, glycerol diglycidyl ether, dibromoneopentyl glycol diglycidyl ether, 1,3,5,6 - tetraglycidyl - 2,4 - hexanediol, bisphenol A type epoxy resins such as EPIKOTE 828 (manufactured by Mitsubishi Chemical Corporation), bisphenol F type epoxy resins such as EPIKOTE 807 (manufactured by Mitsubishi Chemical Corporation), hydrogenated bisphenol A type epoxy resins such as YX - 8000 (manufactured by Mitsubishi Chemical Corporation), epoxy resins containing a biphenyl skeleton such as YX6954BH30 (manufactured by Mitsubishi Chemical Corporation), phenol novolac type epoxy resins such as EPPN - 201 (manufactured by Nippon Kayaku Co., Ltd.), (ortho, meta, para -) cresol novolac type epoxy resins such as EOCN - 102S (manufactured by Nippon Kayaku Co., Ltd.), isocyanuric acid triglycidyl ester such as TEPIC (manufactured by Nissan Chemical Industries, Ltd.), alicyclic epoxy resins such as CELLOXIDE2021P (manufactured by DAICEL Corporation), compounds containing a tertiary nitrogen atom represented by N,N,N',N' - tetraglycidyl - m - xylylenediamine, 1,3 - bis(N,N - diglycidylaminomethyl)cyclohexane or N,N,N',N' - tetraglycidyl - 4,4' - diaminodiphenylmethane; compounds having two or more oxetanyl groups described in paragraphs 0170 to 0175 of WO2011 / 132751; compounds having two or more blocked isocyanate groups described in paragraphs 0046 to 0047 of JP - A - 2014 - 224978; compounds having three or more blocked isocyanate groups described in paragraphs 0119 to 0120 of WO2015 / 141598 (preferably CORONATE AP stable M, CORONATE2503, 2515, 2507, 2513, 2555, MILLIONATE MS - 50 (the above, manufactured by TOSOH Corporation), TAKENATE B - 830, B - 815N, B - 820NSU, B - 842N, B - 846N, B - 870N, B - 874N, B - 882N (the above, manufactured by Mitsui Chemicals, Inc.)) and other compounds having a blocked isocyanate group;The compounds containing two or more oxazoline groups (preferably 2,2'-bis(2-oxazoline), 2,2'-bis(4-methyl-2-oxazoline), 2,2'-bis(5-methyl-2-oxazoline), 1,2,4-tris(2-oxazolinyl)-benzene, EPOCROS (manufactured by Nippon Shokubai Co., Ltd.), etc.) having an oxazoline group as described in paragraph 0115 of JP-A-2007-286597; the compounds having a cyclic carbonate group as described in paragraphs 0025 to 0030 and 0032 of WO2011 / 155577; the compounds having two or more Meldrum's acid structures as described in WO2012 / 091088; the compounds having a hydroxyl group and an alkoxy group such as N,N,N',N'-tetrakis(2-hydroxyethyl)adipamide, 2,2-bis(4-hydroxy-3,5-dihydroxymethylphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethoxyphenyl)propane, 2,2-bis(4-hydroxy-3,5-dihydroxymethylphenyl)-1,1,1,3,3,3-hexafluoropropane; the compounds represented by glycerol mono(meth)acrylate, glycerol di(meth)acrylate (1,2-, 1,3-type mixture), glycerol tri(meth)acrylate, glycerol 1,3-diglycerolate di(meth)acrylate, pentaerythritol tri(meth)acrylate, diethylene glycol mono(meth)acrylate, triethylene glycol mono(meth)acrylate, tetraethylene glycol mono(meth)acrylate, pentaethylene glycol mono(meth)acrylate, hexaethylene glycol mono(meth)acrylate.;

[0196] The content of the above crosslinkable compound is preferably 0.1 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, relative to 100 parts by mass of the polymer component contained in the liquid crystal aligning agent.

[0197] As the compound for promoting imidization described above, a compound having a basic site (e.g., primary amino group, aliphatic heterocycle (e.g., pyrrolidine skeleton), aromatic heterocycle (e.g., imidazole ring, indole ring), or guanidyl group, etc.) is preferred (wherein, the above crosslinkable compound and adhesion promoter are not included); or a compound that generates the above basic site during firing. A compound that generates the above basic site during firing is more preferred. If specific preferred examples are listed, amino acids in which part or all of the basic sites possessed by the amino acids are protected can be listed. As the protecting group for the basic site possessed by the above amino acids, carbamate-based protecting groups such as Boc can be listed. Specific examples of the above amino acids include: glycine, alanine, cysteine, methionine, asparagine, glutamic acid, valine, leucine, phenylalanine, tyrosine, tryptophan, proline, hydroxyproline, arginine, histidine, lysine, ornithine. If more specific preferred examples of the compound for promoting imidization are listed, N-α-(9-fluorenylmethoxycarbonyl)-N-τ-(tert-butoxycarbonyl)-L-histidine can be listed.

[0198] The content of the above compound for promoting imidization contained in the liquid crystal aligning agent of the present invention is preferably 0.1 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, and further preferably 5 to 20 parts by mass with respect to 100 parts by mass of the polymer component contained in the liquid crystal aligning agent.

[0199] The solid content concentration in the liquid crystal aligning agent of the present invention (the proportion of the total mass of the components other than the solvent in the liquid crystal aligning agent in the total mass of the liquid crystal aligning agent) is appropriately selected in consideration of viscosity, volatility, etc., and is preferably in the range of 1 to 10% by mass.

[0200] The particularly preferred range of the solid content concentration varies depending on the method used when coating the liquid crystal aligning agent on the substrate. As described in the subsequent step (1), as the method for coating the liquid crystal aligning agent on the substrate, for example, a roll coater method, a spin coating method, a printing method, an inkjet method, etc. can be listed. In the case of using the roll coater method, the solid content concentration is particularly preferably in the range of 4 to 10% by mass. In the case of using the spin coating method, the solid content concentration is particularly preferably in the range of 1.5 to 4.5% by mass. In the case of using the printing method, the solid content concentration is particularly preferably set in the range of 3 to 9% by mass, thereby setting the solution viscosity in the range of 12 to 50 mPa·s. In the case of using the inkjet method, the solid content concentration is particularly preferably set in the range of 1 to 5% by mass, thereby setting the solution viscosity in the range of 3 to 15 mPa·s. The temperature during the preparation of the liquid crystal aligning agent is preferably 10 to 50 °C, more preferably 20 to 30 °C.

[0201] <Liquid crystal alignment film>

[0202] The liquid crystal alignment film of the present invention is obtained from the above liquid crystal aligning agent. The liquid crystal alignment film of the present invention can be used for a liquid crystal alignment film in a horizontal alignment mode or a vertical alignment mode (VA mode), and the liquid crystal alignment film is a liquid crystal alignment film suitable for a liquid crystal display element in a horizontal alignment mode such as an IPS driving mode or an FFS driving mode. In addition, it is more preferably used for a liquid crystal alignment film for a photo-alignment treatment method. In addition, the liquid crystal alignment film can be effectively applied to various technical uses, for example, it can also be applied to a liquid crystal alignment film other than the above uses (a liquid crystal alignment film for a retardation film, a scanning antenna, a liquid crystal array antenna, or a liquid crystal alignment film for a transmissive scattering type liquid crystal dimming element) or other uses, such as: a protective film (e.g., a protective film for a color filter), a spacer film, an interlayer insulating film, an antireflection film, a wiring coating film, an antistatic film, a motor insulating film (a gate insulating film for a flexible display), etc.

[0203] The liquid crystal alignment film of the present invention can be manufactured, for example, by a method including the following steps (1) to (3).

[0204] <Step (1): Step of coating the liquid crystal aligning agent on a substrate>

[0205] For example, the liquid crystal aligning agent of the present invention is coated on one surface of a substrate provided with a patterned transparent conductive film by an appropriate coating method such as a roll coater method, a spin coating method, a printing method, an inkjet method, etc. Here, as the substrate, as long as it has high transparency, there is no particular limitation, and plastic substrates such as acrylic substrates and polycarbonate substrates can also be used together with glass substrates and silicon nitride substrates. In addition, in a reflective liquid crystal display element, if it is only a single-sided substrate, an opaque object such as a silicon wafer can also be used, and in this case, an electrode that reflects light such as aluminum can also be used for the electrode. In addition, in the case of manufacturing a liquid crystal display element in an IPS driving mode or an FFS driving mode, a substrate provided with an electrode composed of a transparent conductive film or a metal film patterned in a comb shape and a counter substrate without an electrode are used.

[0206] As a method of coating and forming a liquid crystal aligning agent on a substrate, there can be mentioned: screen printing, offset printing, flexographic printing, inkjet method, or spraying method, etc. Among them, a coating and forming method using the inkjet method can be preferably used.

[0207] An IPS substrate, which is a comb electrode substrate used in the IPS mode, has: a substrate; a plurality of linear electrodes formed on the substrate and arranged in a comb shape; and a liquid crystal alignment film formed on the substrate so as to cover the linear electrodes.

[0208] Note that the FFS substrate, which is a comb-shaped electrode substrate used in the FFS mode, has: a substrate; a surface electrode formed on the substrate; an insulating film formed on the surface electrode; a plurality of linear electrodes formed on the insulating film and arranged in a comb shape; and a liquid crystal alignment film formed on the insulating film so as to cover the linear electrodes.

[0209] Figure 1 It is a schematic cross-sectional view of an example of an in-plane switching (IPS) mode transverse electric field liquid crystal display element having a liquid crystal alignment film obtained from the liquid crystal aligning agent of the present invention.

[0210] In Figure 1 In the transverse electric field liquid crystal display element 1 exemplified in, a liquid crystal 3 is sandwiched between a comb-shaped electrode substrate 2 having a liquid crystal alignment film 2c and a counter substrate 4 having a liquid crystal alignment film 4a. The comb-shaped electrode substrate 2 has: a substrate 2a; a plurality of linear electrodes 2b formed on the substrate 2a and arranged in a comb shape; and a liquid crystal alignment film 2c formed on the substrate 2a so as to cover the linear electrodes 2b. The counter substrate 4 has: a substrate 4b; and a liquid crystal alignment film 4a formed on the substrate 4b. The liquid crystal alignment film 2c is the liquid crystal alignment film of the present invention. The liquid crystal alignment film 4a is also the liquid crystal alignment film of the present invention.

[0211] In Figure 1 In the transverse electric field liquid crystal display element 1 of, when a voltage is applied to the linear electrodes 2b, an electric field is generated between the linear electrodes 2b as shown by the power line L.

[0212] Figure 2 It is a schematic cross-sectional view of another example of an FFS mode transverse electric field liquid crystal display element having a liquid crystal alignment film obtained from the liquid crystal aligning agent of the present invention.

[0213] In Figure 2 In the transverse electric field liquid crystal display element 1 exemplified in, a liquid crystal 3 is sandwiched between a comb-shaped electrode substrate 2 having a liquid crystal alignment film 2h and a counter substrate 4 having a liquid crystal alignment film 4a. The comb-shaped electrode substrate 2 has: a substrate 2d; a surface electrode 2e formed on the substrate 2d; an insulating film 2f formed on the surface electrode 2e; a plurality of linear electrodes 2g formed on the insulating film 2f and arranged in a comb shape; and a liquid crystal alignment film 2h formed on the insulating film 2f so as to cover the linear electrodes 2g. The counter substrate 4 has: a substrate 4b; and a liquid crystal alignment film 4a formed on the substrate 4b. The liquid crystal alignment film 2h is the liquid crystal alignment film of the present invention. The liquid crystal alignment film 4a is also the liquid crystal alignment film of the present invention.

[0214] In Figure 2 In the transverse electric field liquid crystal display element 1 of, when a voltage is applied to the surface electrode 2e and the linear electrodes 2g, an electric field is generated between the surface electrode 2e and the linear electrodes 2g as shown by the power line L.

[0215] <Process (2): Process of baking the coated liquid crystal aligning agent>

[0216] Process (2) is a process of baking the liquid crystal aligning agent coated on a substrate to form a film. After coating the liquid crystal aligning agent on the substrate, a heating unit such as a hot plate, a hot air circulation oven, or an IR (infrared) type oven can be used to evaporate the solvent, or thermal imidization of polyamic acid or polyamic acid ester can be performed. The drying and baking processes after coating the liquid crystal aligning agent of the present invention can be performed at any temperature and time, and can also be performed multiple times. As the baking temperature, for example, it can be performed at 40 to 180°C. From the viewpoint of shortening the process, it can be performed at 40 to 150°C. As the baking time, there is no particular limitation, and examples include 1 to 10 minutes, preferably 1 to 5 minutes. In the case of performing thermal imidization of a polyimide precursor typified by polyamic acid or polyamic acid ester, in the case of applying a high-boiling solvent to the liquid crystal aligning agent, after the above baking process, for example, a baking process can be performed in a temperature range of 150 to 300°C, preferably 150 to 250°C. As the baking time, there is no particular limitation, and examples include a baking time of 5 to 40 minutes, preferably 5 to 30 minutes.

[0217] If the baked film-like material is too thin, the reliability of the liquid crystal display element may sometimes decrease, so it is preferably 5 to 300 nm, more preferably 10 to 200 nm.

[0218] <Process (3): Process of performing an alignment treatment on the film obtained in Process (2)>

[0219] Process (3) is a process of performing an alignment treatment on the film obtained in Process (2) as needed. That is, in a liquid crystal display element using a horizontal alignment method such as an IPS driving method or an FFS driving method, an alignment treatment can be imparted to the coated film. On the other hand, in a liquid crystal display element using a vertical alignment method such as a VA method or a PSA method, the formed coated film can be used as it is as a liquid crystal alignment film, or an alignment treatment can be performed on the coated film. As a method for aligning the liquid crystal alignment film, a rubbing treatment method and a photoalignment treatment method can be cited, and a photoalignment treatment method is more preferable. As the photoalignment treatment method, the following method can be cited: irradiating the surface of the above film-like material with radiation polarized in a certain direction, and performing a heat treatment as appropriate to impart liquid crystal alignment (also referred to as liquid crystal alignment energy). As the radiation, ultraviolet rays or visible light having a wavelength of 100 to 800 nm can be used. Among them, ultraviolet rays having a wavelength of 100 to 400 nm are preferred, and ultraviolet rays having a wavelength of 200 to 400 nm are more preferred.

[0220] The irradiation amount of the above radiation is preferably 1 to 10000 mJ / cm 2, more preferably 100 - 5000 mJ / cm 2 , further preferably 100 - 1500 mJ / cm 2 , particularly preferably 100 - 1000 mJ / cm 2 , even more preferably 100 - 400 mJ / cm 2 .

[0221] As the light source of the irradiation light, for example, the following can be used: low-pressure mercury lamp, high-pressure mercury lamp, deep ultraviolet (Deep UV) lamp, deuterium lamp, metal halide lamp, argon resonance lamp, xenon lamp, mercury-xenon lamp, excimer laser (e.g., KrF excimer laser), fluorescent lamp, LED lamp, halogen lamp (e.g., sodium lamp), microwave-excited electrodeless lamp, etc.

[0222] In addition, when polarized light is used as the irradiation light, the higher the extinction ratio of the polarized light, the higher the anisotropy can be imparted. For example, in the case of ultraviolet light, the extinction ratio of polarized ultraviolet light is more preferably 10:1 or more, and further preferably 20:1 or more.

[0223] In addition, when irradiating with radiation, in order to improve the liquid crystal alignment property, the substrate having the film-like substance can be irradiated while being heated at 50 - 250 °C. The liquid crystal alignment film thus produced can make the liquid crystal molecules stably align in a certain direction.

[0224] Moreover, in the above method, the liquid crystal alignment film irradiated with polarized radiation can be subjected to a contact treatment with water or a solvent, or the liquid crystal alignment film irradiated with radiation can be subjected to a heat treatment.

[0225] As the solvent for the above contact treatment, there is no particular limitation as long as it is a solvent that dissolves the decomposition products generated from the film-like substance by the irradiation of radiation. Specific examples include: water, methanol, ethanol, 2-propanol, acetone, methyl ethyl ketone, 1-methoxy-2-propanol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, methyl lactate, diacetone alcohol, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propyl acetate, butyl acetate, cyclohexyl acetate, etc. Among them, considering the versatility and the safety of the solvent, water, 2-propanol, 1-methoxy-2-propanol or ethyl lactate is preferred. More preferably, water, 1-methoxy-2-propanol or ethyl lactate. The solvent can be one kind or a combination of two or more kinds.

[0226] The film coated with radiation or the film subjected to the contact treatment can also be subjected to a heat treatment. The temperature of the heat treatment is preferably 50 - 300 °C, more preferably 120 - 250 °C. As the time of the heat treatment, it is preferably set to 1 - 30 minutes respectively.

[0227] <Liquid crystal display element>

[0228] The liquid crystal display element of the present invention includes the liquid crystal alignment film of the present invention.

[0229] The liquid crystal display element of the present invention can be manufactured, for example, by a method including the following step (4).

[0230] The liquid crystal display element of the present invention can preferably be manufactured by a method including the above steps (1) to (3) and the following step (4).

[0231] <Step (4): Step of manufacturing a liquid crystal cell>

[0232] As described above, two substrates formed with liquid crystal alignment films are prepared, and liquid crystal is disposed between the two substrates disposed opposite to each other. Specifically, the following two methods can be cited.

[0233] In the first method, first, two substrates are disposed opposite to each other with a gap (cell gap) therebetween in such a manner that their respective liquid crystal alignment films face each other. Then, the peripheral portions of the two substrates are bonded to each other using a sealant, and a liquid crystal composition is filled into the cell gap defined by the substrate surfaces and the sealant through an injection hole. After contacting the film surface, the injection hole is sealed.

[0234] The second method is a method called the ODF (One Drop Fill) method. For example, an ultraviolet curable sealant is applied to a predetermined portion on one of the two substrates formed with liquid crystal alignment films, and the liquid crystal composition is further dropped at several predetermined locations on the liquid crystal alignment film surface. Then, the other substrate is bonded in such a manner that the liquid crystal alignment films face each other, and the liquid crystal composition is spread over the entire surface of the substrate and brought into contact with the film surface. Then, ultraviolet light is irradiated onto the entire surface of the substrate to cure the sealant.

[0235] In any case of using the above methods, it is desirable to further heat to the temperature at which the liquid crystal composition used becomes an isotropic phase and then slowly cool to room temperature, thereby removing the flow alignment during liquid crystal filling.

[0236] It should be noted that in the case where the coating film has been subjected to a rubbing treatment, the two substrates are disposed opposite to each other in such a manner that the rubbing directions of the respective coating films form a predetermined angle, for example, an orthogonal or antiparallel angle.

[0237] As the sealant, for example, an epoxy resin containing a curing agent and alumina balls as spacers can be used.

[0238] The above liquid crystal composition is not particularly limited and is a composition containing at least one liquid crystal compound (liquid crystal molecule). Various liquid crystal compositions with positive or negative dielectric anisotropy can be used. It should be noted that hereinafter, a liquid crystal composition with positive dielectric anisotropy is also referred to as a positive-type liquid crystal, and a liquid crystal composition with negative dielectric anisotropy is also referred to as a negative-type liquid crystal.

[0239] Examples of the liquid crystal composition include a nematic liquid crystal composition, a smectic liquid crystal composition, and a cholesteric liquid crystal composition. Among them, a nematic liquid crystal composition is preferred.

[0240] The above liquid crystal composition may contain a liquid crystal compound having a fluorine atom, a hydroxyl group, an amino group, a fluorine atom-containing group (such as trifluoromethyl), a cyano group, an alkyl group, an alkoxy group, an alkenyl group, an isothiocyanate group, a heterocycle, a cycloalkane, a cycloalkene, a steroid skeleton, a benzene ring, or a naphthalene ring, or may also contain a compound having two or more rigid sites (mesogenic skeletons) exhibiting liquid crystallinity in the molecule (for example, a bis-mesogenic compound in which two rigid biphenyl structures or terphenyl structures are linked by an alkyl group).

[0241] From the viewpoint of improving liquid crystal alignment, additives may be further added to the above liquid crystal composition. Examples of such additives include compounds having a polymerizable group ((meth)acryloyl group, etc.) (hereinafter, also referred to as polymerizable compounds); optically active compounds (e.g., S-811 manufactured by Merck & Co., Inc.); antioxidants; ultraviolet absorbers; pigments; defoamers; polymerization initiators; or polymerization inhibitors, etc.

[0242] Examples of the positive-type liquid crystal include ZLI-2293, ZLI-4792, MLC-2003, MLC-2041, MLC-3019, or MLC-7081 manufactured by Merck & Co., Inc.; PA-1492 manufactured by DIC Corporation, etc.

[0243] Examples of the negative-type liquid crystal include MLC-6608, MLC-6609, MLC-6610, MLC-6882, MLC-6886, MLC-7026, MLC-7026-000, MLC-7026-100, or MLC-7029 manufactured by Merck & Co., Inc.

[0244] In addition, examples of the liquid crystal containing a compound having a polymerizable group include MLC-3023 manufactured by Merck & Co., Inc.

[0245] The liquid crystal aligning agent of the present invention is also preferably used for a liquid crystal display element (PSA method liquid crystal display element) manufactured through the following steps and having a liquid crystal layer between a pair of substrates provided with electrodes: A liquid crystal composition containing a polymerizable compound polymerized by at least one of active energy rays and heat is disposed between the pair of substrates, a voltage is applied between the electrodes, and the polymerizable compound is polymerized by at least one of irradiation with active energy rays and heating.

[0246] In addition, the liquid crystal aligning agent of the present invention is also preferably used for a liquid crystal display element (SC-PVA method liquid crystal display element) manufactured through the following steps and having a liquid crystal layer between a pair of substrates provided with electrodes: A liquid crystal alignment film containing a polymerizable group polymerized by at least one of active energy rays and heat is disposed between the above-mentioned pair of substrates, and a voltage is applied between the electrodes.

[0247] <Process (4-1): In the case of a PSA method liquid crystal display element>

[0248] Inject or drop a liquid crystal composition containing a polymerizable compound, and otherwise, carry out in the same manner as in the above (4). As the polymerizable compound, for example, compounds having one or more polymerizable groups such as acrylate groups and methacrylate groups in the molecule can be cited.

[0249] <Process (4-2): In the case of an SC-PVA method liquid crystal display element>

[0250] It is also possible to adopt a method of manufacturing a liquid crystal display element by carrying out in the same manner as in the above (4) and then through a process of irradiating ultraviolet rays described later. According to this method, similar to the case of manufacturing the above-mentioned PSA method liquid crystal display element, a liquid crystal display element excellent in response speed under a small light irradiation amount can be obtained.

[0251] The polymerizable compound may be a compound having one or more of the above-mentioned polymerizable groups in the molecule, and its content is preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass, based on 100 parts by mass of all the polymer components contained in the liquid crystal aligning agent.

[0252] In addition, the above-mentioned polymerizable group may also be present in the polymer used for the liquid crystal aligning agent. As such a polymer, for example, a polymer obtained by using a diamine component containing a diamine having the above-mentioned photopolymerizable group at the end for the reaction can be cited.

[0253] <Process (4-3): Process of irradiating ultraviolet rays>

[0254] While applying a voltage between the conductive films of a pair of substrates obtained in the above (4-1) or (4-2), the liquid crystal cell is irradiated with light. The voltage applied herein can be, for example, a direct current or an alternating current of 5 to 50 V. In addition, as the light for irradiation, for example, ultraviolet light and visible light including light having a wavelength of 150 to 800 nm can be used, and ultraviolet light containing light having a wavelength of 300 to 400 nm is preferably 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, etc. can be used. The irradiation amount of light is preferably 1000 to 200000 J / m 2 , more preferably 1000 to 100000 J / m 2 .

[0255] Moreover, a liquid crystal display element can be obtained by attaching a polarizing plate to the outer surface of the liquid crystal cell as needed. 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 cellulose acetate protective film; or a polarizing plate composed of the H film itself, which is formed by stretching and orienting polyvinyl alcohol and absorbing iodine.

[0256] [Examples]

[0257] Hereinafter, examples will be given to explain the present invention in more detail, but the present invention is not limited to these examples. The abbreviations of the following compounds and the measurement methods of each property are as follows.

[0258] (Organic solvent)

[0259] DMF: N,N-dimethylformamide.

[0260] THF: Tetrahydrofuran.

[0261] NMP: N-methyl-2-pyrrolidone.

[0262] BCS: Ethylene glycol monobutyl ether.

[0263] (Tetracarboxylic dianhydride)

[0264] CA-1 to CA-3: Compounds represented by the following formulas (CA-1) to (CA-3) respectively.

[0265]

[0266] Among the above tetracarboxylic dianhydrides, CA-1 is included in the range of specific tetracarboxylic acid (1').

[0267] (Diamine)

[0268] DA-1 to DA-13: Compounds represented by the following formulas (DA-1) to (DA-13) respectively.

[0269]

[0270] Among the above diamines, DA-3, DA-5, DA-6, and DA-11 are within the ranges of specific diamine (1) and specific diamine (1'), and DA-12 and DA-13 are within the range of specific diamine (1').

[0271] (Additive)

[0272] S-1: A compound represented by the following formula (S-1).

[0273] AD-1: A compound represented by the following formula (AD-1).

[0274]

[0275] <Measurement of Viscosity>

[0276] Measurement was carried out using an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.), with a sample volume of 1.1 mL, using a conical rotor TE-1 (1°34', R24), at a temperature of 25°C.

[0277] <Measurement of Molecular Weight>

[0278] Measurement was carried out using the following normal-temperature GPC (gel permeation chromatography) apparatus, and Mn and Mw were calculated in terms of polyethylene glycol and polyethylene oxide conversion values.

[0279] GPC apparatus: GPC-101 (manufactured by Showa Denko KK), chromatographic columns: GPC KD-803 and GPC KD-805 (manufactured by Showa Denko KK) in series, column temperature: 50°C, eluent: N,N-dimethylformamide (as an additive, lithium bromide monohydrate (LiBr·H2O) is 30 mmol / L, phosphoric acid·anhydrous crystal (o-phosphoric acid) is 30 mmol / L, tetrahydrofuran (THF) is 10 mL / L), flow rate: 1.0 mL / minute.

[0280] Standard samples for calibration curve preparation: TSK standard polyethylene oxide (molecular weights; approximately 900000, approximately 150000, approximately 100000, and approximately 30000) (manufactured by TOSOH Corporation) and polyethylene glycol (molecular weights; approximately 12000, approximately 4000, and approximately 1000) (manufactured by Polymer Laboratories).

[0281] [Synthesis of Monomer]

[0282] DA-3 was synthesized based on the method described in JP-A-61-130264.

[0283] DA-5, DA-11, and DA-12 are synthesized by the methods described below.

[0284] DA-6 and DA-13 are novel compounds not disclosed in the literature and the like. The synthesis methods are described in detail below.

[0285] The products described in the following Monomer Synthesis Examples 1 to 5 are identified by 1 H-NMR analysis (analysis conditions are as follows).

[0286] Apparatus: Fourier transform superconducting nuclear magnetic resonance apparatus (FT-NMR) "AVANCE III" (manufactured by BRUKER), 500 MHz.

[0287] Solvent: Deuterated dimethyl sulfoxide (DMSO-d6, standard substance: tetramethylsilane).

[0288] (Monomer Synthesis Example 1; Synthesis of DA-5)

[0289] DA-5 was synthesized according to the route shown below.

[0290]

[0291] Under a nitrogen atmosphere, 2-(4-nitrophenoxy)ethyl methanesulfonate (19.6 g, 75.0 mmol), 4-nitro-m-cresol (11.5 g, 75.0 mmol), potassium carbonate (25.9 g, 187 mmol), and DMF (293 g) were added to a 500 mL four-necked flask, and the mixture was stirred at 100 °C for 3 hours for reaction. After the reaction, it was cooled to 25 °C, 600 g of water was added, and the precipitated solid was filtered out. The precipitated solid was washed three times with water (200 g) in sequence as a filter cake, washed with methanol (200 g) as a filter cake, and the filtered solid was dried to obtain DA-5-1 (22.9 g, 71.9 mmol, yield 96%, white solid).

[0292]

[0293] Under a nitrogen atmosphere, the above-obtained DA-5-1 (22.9 g, 71.9 mmol), THF (457 g), and palladium on carbon (5% Pd carbon powder (50% water-containing product) K type, manufactured by N.E. CHEMCAT Corporation, 2.28 g) were added to a 500 mL four-necked flask. After replacing with a hydrogen atmosphere, the reaction was carried out at normal pressure and room temperature (25 °C). After the reaction was completed, palladium on carbon was removed by filtration, and the obtained filtrate was concentrated. Isopropanol (160 g) was added to the obtained crude product to filter out crystals, and the crystals were dried to obtain DA-5 (15.5 g, 59.8 mmol, yield 83%, white solid). According to the following shown 1The result of 1H-NMR confirmed that this solid was DA-5.

[0294] 1 1H-NMR (500 MHz, DMSO-d6): δ (ppm) = 6.67 (d, 2H), 6.60 (s, 1H), 6.53 - 6.49 (m, 4H), 4.06 (s, 2H), 4.37 (s, 2H), 4.07 (s, 4H), 2.02 (s, 3H).

[0295] (Monomer Synthesis Example 2; Synthesis of DA-6)

[0296] DA-6 was synthesized according to the route shown below.

[0297]

[0298] Under a nitrogen atmosphere, ethylene glycol (3.71 g, 59.8 mmol), 5-fluoro-2-nitroanisole (20.7 g, 121 mmol), potassium hydroxide (8.89 g, 158 mmol), and NMP (122 g) were added to a 500 mL four-necked flask, and the reaction was carried out with stirring at 80 °C for 5 hours. After the reaction was completed, it was cooled to 25 °C, water (100 g) was added, the precipitated solid was filtered out, and the precipitated solid was washed as a filter cake with water (100 g) three times in sequence, washed as a filter cake with methanol (78 g), and washed as a filter cake with acetonitrile (90 g). Acetonitrile (141 g) was added to the obtained solid, and it was stirred into a slurry state under reflux conditions for 2 hours, then cooled to 25 °C, and the obtained solid was filtered out and dried to obtain DA-6-1 (12.2 g, 33.5 mmol, yield 56%, yellow solid).

[0299]

[0300] Under a nitrogen atmosphere, the above-obtained DA-6-1 (12.2 g, 33.5 mmol), DMF (143 g), and palladium on carbon (5% Pd carbon powder (50% water-containing product) K type, manufactured by N.E. CHEMCAT Corporation, 1.10 g) were added to a 500 mL four-necked flask. After replacing it with a hydrogen atmosphere, the reaction was carried out at normal pressure and normal temperature (25 °C). After the reaction was completed, palladium on carbon was removed by filtration, the obtained filtrate was concentrated to obtain a crude product (24.0 g). Isopropanol (94.2 g) was added to the crude product, and then it was cooled to -18 °C to crystallize. After the crystals were filtered out, the filter cake was washed twice with isopropanol (20.0 g), and then dried to obtain DA-6 (4.68 g, 15.4 mmol, yield 46%, purple solid). According to the 1 The result of 1H-NMR confirmed that this solid was DA-6.

[0301] 1 H-NMR (500 MHz, DMSO-d6): δ (ppm) = 6.54 (d, 2H, J = 8.4 Hz), 6.49 (d, 2H, J = 2.6 Hz), 6.33 (dd, 2H, J = 8.4 Hz, 2.6 Hz), 4.25 (s, 4H), 4.12 (s, 4H), 3.74 (s, 6H).

[0302] (Synthesis Example of Monomer 3; Synthesis of DA-11)

[0303] DA-11 was synthesized according to the route shown below.

[0304]

[0305] Under a nitrogen atmosphere, dichloromethane (26.0 g, 97.0 mmol), 4-nitro-m-cresol (29.7 g, 194 mmol), potassium carbonate (26.8 g, 194 mmol), and DMF (300 g) were added to a 1 L four-necked flask, and the mixture was heated and stirred at 100 °C for reaction. After the reaction, 500 g of pure water was added, and the precipitated solid was filtered out. The precipitated solid was washed with pure water (140 g) as a filter cake, washed with methanol (140 g) as a filter cake, the filtered solid was obtained, and dried to obtain DA-11-1 (22.1 g, 69.5 mmol, yield 72%, brown crystals). According to the 1 results of H-NMR shown below, it was confirmed that this solid was DA-11-1.

[0306] 1 H-NMR (500 MHz, DMSO-d6): δ (ppm) = 8.07 (d, 2H), 7.21 (s, 2H), 7.20 - 7.16 (m, 2H), 6.10 (s, 2H), 2.54 (s, 6H).

[0307]

[0308] Under a nitrogen atmosphere, the above-obtained DA-11-1 (22.1 g, 69.5 mmol), THF (400 g), and palladium on carbon (5% Pd carbon powder (50% water-containing product) K type, manufactured by N.E. CHEMCAT Corporation, 2.21 g) were added to a 1 L four-necked flask. After replacing with a hydrogen atmosphere, the reaction was carried out at normal pressure and room temperature. After the reaction was completed, palladium on carbon was removed by filtration, and the obtained filtrate was concentrated. Methanol (150 g) was added to the obtained crude product, and the crystals were filtered out and dried to obtain DA-11 (17.0 g, 65.9 mmol, yield 94.9%, light peach solid). According to the 1The results of 1H-NMR confirmed that the solid was DA-11.

[0309] 1 1H-NMR (500 MHz, DMSO-d6): δ (ppm) = 6.68 (d, 2H), 6.67 - 6.62 (m, 2H), 6.53 (d, 2H), 5.44 (s, 2H), 4.48 (s, 4H), 2.02 (s, 6H).

[0310] (Monomer Synthesis Example 4; Synthesis of DA-12)

[0311] DA-12 was synthesized according to the route shown below.

[0312]

[0313] Under a nitrogen atmosphere, 1-(4-chlorobutoxy)-4-nitrobenzene (20.7 g, 90 mmol), 4-nitro-m-cresol (13.8 g, 90 mmol), potassium carbonate (31.1 g, 225.0 mmol), and DMF (200 g) were added to a 500 mL four-necked flask, and the mixture was heated and stirred at 100 °C for reaction. After the reaction, 300 g of pure water was added, and the precipitated solid was filtered out. The precipitated solid was washed with pure water (100 g) as a filter cake, washed with methanol (100 g) as a filter cake, the filtered solid was obtained, and dried to obtain DA-12-1 (19.3 g, 55.7 mmol, yield 61.9%, orange solid). According to the following shown 1 The results of 1H-NMR confirmed that the solid was DA-12-1.

[0314] 1 1H-NMR (500 MHz, DMSO-d6): δ (ppm) = 8.20 (d, 2H), 8.04 (d, 1H), 7.18 - 6.99 (m, 4H), 4.31 - 4.26 (m, 4H), 2.54 (s, 3H), 1.92 (m, 4H).

[0315]

[0316] Under a nitrogen atmosphere, into a 1 L four-necked flask, the above-obtained DA-12-1 (19.0 g, 55.0 mmol), THF (380 g), and palladium on carbon (5% Pd carbon powder (50% water-containing product), type K, manufactured by N.E. CHEMCAT Corporation, 1.90 g) were added. After replacing with a hydrogen atmosphere, the reaction was carried out at normal pressure and room temperature. After the reaction was completed, the palladium on carbon was removed by filtration, and the obtained filtrate was concentrated. Methanol (100 g) was added to the obtained crude product, and the crystals were filtered out and dried to obtain DA-12 (10.4 g, 36.2 mmol, yield 65.8%, yellow solid). According to the 1 results of the 1H-NMR shown below, it was confirmed that this solid was DA-12.

[0317] 1 1H-NMR (500 MHz, DMSO-d6): δ (ppm) = 6.65 - 6.49 (m, 7H), 4.57 (s, 2H), 4.34 (s, 2H), 3.85 (s, 4H), 2.02 (s, 3H), 1.78 - 1.73 (m, 4H).

[0318] (Monomer synthesis example 5; Synthesis of DA-13)

[0319] DA-13 was synthesized according to the route shown below.

[0320]

[0321] Under a nitrogen atmosphere, into a 500 mL four-necked flask, 1-propanol, 3-(4-nitrophenoxy)-1-methanesulfonate (17.9 g, 65 mmol), 4-nitro-m-cresol (9.9 g, 65 mmol), potassium carbonate (22.5 g, 162.5 mmol), and DMF (270 g) were added, and the reaction was carried out with heating and stirring at 100 °C. After the reaction, 750 g of pure water was added, and the precipitated solid was filtered out. The precipitated solid was washed with pure water (180 g) in sequence for cake washing, washed with methanol (180 g) for cake washing, and the obtained solid was filtered out and dried to obtain DA-13-1 (20.5 g, 61.6 mmol, yield 94.7%, white solid). According to the 1 results of the 1H-NMR shown below, it was confirmed that this solid was DA-13-1.

[0322] 1 1H-NMR (500 MHz, DMSO-d6): δ (ppm) = 8.20 (d, 2H), 8.04 (d, 1H), 7.18 - 6.99 (m, 4H), 4.31 - 4.26 (m, 4H), 2.54 (s, 3H), 2.25 (m, 2H).

[0323]

[0324] Under a nitrogen atmosphere, into a 1 L four-necked flask, the above-obtained DA-13-1 (20.5 g, 61.6 mmol), THF (200 g), and palladium on carbon (5% Pd carbon powder (50% water-containing product), type K, manufactured by N.E. CHEMCAT Corporation, 2.05 g) were added. After replacing with a hydrogen atmosphere, the reaction was carried out at normal pressure and room temperature. After the reaction was completed, palladium on carbon was removed by filtration, and the obtained filtrate was concentrated. Methanol (100 g) was added to the obtained crude product, and crystals were filtered out and dried to obtain DA-13 (13.5 g, 49.7 mmol, yield 80.8%, peach-white solid). According to the 1 results of 1H-NMR shown below, it was confirmed that this solid was DA-13.

[0325] 1 1H-NMR (500 MHz, DMSO-d6): δ (ppm) = 6.65 - 6.49 (m, 7H), 4.57 (s, 2H), 4.34 (s, 2H), 3.94 (m, 4H), 2.02 - 2.00 (m, 5H).

[0326] [Synthesis of Polymer]

[0327] <Synthesis Example 1>

[0328] Into a 50 mL four-necked flask equipped with a stirring device and a nitrogen inlet tube, DA-1 (0.487 g, 4.50 mmol), DA-2 (1.10 g, 4.50 mmol), DA-3 (0.817 g, 3.00 mmol), DA-4 (1.20 g, 3.00 mmol), and NMP (41.4 g) were added. While introducing nitrogen, it was stirred and dissolved at room temperature (23 °C). Then, after cooling to 15 °C, CA-1 (3.10 g, 13.8 mmol) and NMP (7.74 g) were added, and it was stirred at 40 °C for 20 hours to obtain a solution of polyamic acid (PAA-1) with a solid component concentration of 12% by mass (viscosity: 170 mPa·s). The Mn of this polyamic acid was 8708, and the Mw was 19802.

[0329] <Synthesis Example 2>

[0330] In a 50 mL four-necked flask equipped with a stirring device and a nitrogen inlet tube, DA-1 (0.259 g, 2.40 mmol), DA-2 (0.586 g, 2.40 mmol), DA-5 (0.413 g, 1.60 mmol), DA-4 (0.638 g, 1.60 mmol), and NMP (21.8 g) were added, and while introducing nitrogen, the mixture was stirred at room temperature until dissolved. Then, after cooling to 15 °C, CA-1 (1.65 g, 7.38 mmol) and NMP (4.24 g) were added, and the mixture was stirred at 40 °C for 24 hours to obtain a solution of polyamic acid (PAA-2) with a solid component concentration of 12% by mass (viscosity: 224 mPa·s). The Mn of this polyamic acid was 7976, and the Mw was 20395.

[0331] <Synthesis Example 3>

[0332] In a 50 mL four-necked flask equipped with a stirring device and a nitrogen inlet tube, DA-1 (0.324 g, 3.00 mmol), DA-2 (0.733 g, 3.00 mmol), DA-6 (0.609 g, 2.00 mmol), DA-4 (0.797 g, 2.00 mmol), and NMP (28.3 g) were added, and while introducing nitrogen, the mixture was stirred at room temperature until dissolved. Then, after cooling to 15 °C, CA-1 (2.08 g, 9.28 mmol) and NMP (5.01 g) were added, and the mixture was stirred at 40 °C for 24 hours to obtain a solution of polyamic acid (PAA-3) with a solid component concentration of 12% by mass (viscosity: 184 mPa·s). The Mn of this polyamic acid was 9245, and the Mw was 24564.

[0333] <Synthesis Example 4>

[0334] In a 50 mL four-necked flask equipped with a stirring device and a nitrogen inlet tube, DA-1 (0.422 g, 3.90 mmol), DA-2 (0.953 g, 3.90 mmol), DA-7 (0.708 g, 2.60 mmol), DA-4 (1.04 g, 2.60 mmol), and NMP (35.9 g) were added, and while introducing nitrogen, the mixture was stirred at room temperature until dissolved. Then, after cooling to 15 °C, CA-1 (2.65 g, 11.8 mmol) and NMP (6.52 g) were added, and the mixture was stirred at 40 °C for 20 hours to obtain a solution of polyamic acid (PAA-4) with a solid component concentration of 12% by mass (viscosity: 209 mPa·s). The Mn of this polyamic acid was 8745, and the Mw was 20201.

[0335] <Synthesis Example 5>

[0336] In a 50 mL four-necked flask equipped with a stirring device and a nitrogen inlet tube, DA-1 (0.292 g, 2.70 mmol), DA-2 (0.660 g, 2.70 mmol), DA-8 (0.905 g, 1.80 mmol), DA-4 (0.717 g, 1.80 mmol), and NMP (29.6 g) were added, and while introducing nitrogen, the mixture was stirred at room temperature until dissolved. Then, after cooling to 15 °C, CA-1 (1.90 g, 8.46 mmol) and NMP (3.23 g) were added, and the mixture was stirred at 40 °C for 24 hours, thereby obtaining a solution of polyamic acid (PAA-5) with a solid component concentration of 12% by mass (viscosity: 269 mPa·s). The Mn of this polyamic acid was 9940, and the Mw was 24082.

[0337] <Synthesis Example 6>

[0338] In a 50 mL four-necked flask equipped with a stirring device and a nitrogen inlet tube, DA-9 (2.69 g, 9.00 mmol), DA-10 (0.901 g, 6.00 mmol), and NMP (29.0 g) were added, and while introducing nitrogen, the mixture was stirred at room temperature until dissolved. Then, after cooling to 15 °C, CA-2 (2.82 g, 14.4 mmol) and NMP (7.31 g) were added, and the mixture was stirred at room temperature for 2 hours, thereby obtaining a solution of polyamic acid (PAA-6) with a solid component concentration of 15% by mass (viscosity: 740 mPa·s). The Mn of this polyamic acid was 10933, and the Mw was 28600.

[0339] <Synthesis Example 7>

[0340] In a 50 mL four-necked flask equipped with a stirring device and a nitrogen inlet tube, DA-1 (0.324 g, 3.00 mmol), DA-2 (0.733 g, 3.00 mmol), DA-11 (0.517 g, 2.00 mmol), DA-4 (0.797 g, 2.00 mmol), and NMP (27.3 g) were added, and while introducing nitrogen, the mixture was stirred at room temperature until dissolved. Then, after cooling to 15 °C, CA-1 (2.05 g, 9.13 mmol) and NMP (5.13 g) were added, and the mixture was stirred at 40 °C for 24 hours, thereby obtaining a solution of polyamic acid (PAA-7) with a solid component concentration of 12% by mass (viscosity: 192 mPa·s). The Mn of this polyamic acid was 9404, and the Mw was 21681.

[0341] <Synthesis Example 8>

[0342] In a 50 mL four-necked flask equipped with a stirring device and a nitrogen inlet tube, DA-1 (0.324 g, 3.00 mmol), DA-2 (0.733 g, 3.00 mmol), DA-12 (0.573 g, 2.00 mmol), DA-4 (0.797 g, 2.00 mmol), and NMP (27.9 g) were added, and while nitrogen was being fed, the mixture was stirred at room temperature until dissolved. Then, after cooling to 15 °C, CA-1 (2.04 g, 9.09 mmol) and NMP (4.83 g) were added, and the mixture was stirred at 40 °C for 24 hours, thereby obtaining a solution of polyamic acid (PAA-8) with a solid component concentration of 12% by mass (viscosity: 193 mPa·s). The Mn of this polyamic acid was 7745, and the Mw was 18827.

[0343] <Synthesis Example 9>

[0344] In a 50 mL four-necked flask equipped with a stirring device and a nitrogen inlet tube, DA-1 (0.324 g, 3.00 mmol), DA-2 (0.733 g, 3.00 mmol), DA-13 (0.545 g, 2.00 mmol), DA-4 (0.797 g, 2.00 mmol), and NMP (27.6 g) were added, and while nitrogen was being fed, the mixture was stirred at room temperature until dissolved. Then, after cooling to 15 °C, CA-1 (2.12 g, 9.45 mmol) and NMP (5.11 g) were added, and the mixture was stirred at 40 °C for 24 hours, thereby obtaining a solution of polyamic acid (PAA-9) with a solid component concentration of 12% by mass (viscosity: 230 mPa·s). The Mn of this polyamic acid was 9559, and the Mw was 24905.

[0345] <Synthesis Example 10>

[0346] In a 50 mL four-necked flask equipped with a stirring device and a nitrogen inlet tube, DA-5 (2.07 g, 8.00 mmol) and NMP (23.8 g) were added, and while nitrogen was being fed, the mixture was stirred at room temperature until dissolved. Then, after cooling to 15 °C, CA-1 (1.67 g, 7.44 mmol) and NMP (3.62 g) were added, and the mixture was stirred at 40 °C for 20 hours, thereby obtaining a solution of polyamic acid (PAA-10) with a solid component concentration of 12% by mass (viscosity: 200 mPa·s). The Mn of this polyamic acid was 9618, and the Mw was 20699.

[0347] <Synthesis Example 11>

[0348] In a 50 mL four-necked flask equipped with a stirring device and a nitrogen inlet tube, DA-13 (2.18 g, 8.00 mmol) and NMP (25.1 g) were added, and while nitrogen was being fed, the mixture was stirred at room temperature until dissolved. Then, after cooling to 15 °C, CA-1 (1.67 g, 7.44 mmol) and NMP (3.15 g) were added, and the mixture was stirred at 40 °C for 20 hours, thereby obtaining a solution of polyamic acid (PAA-11) with a solid component concentration of 12% by mass (viscosity: 78 mPa·s). The Mn of this polyamic acid was 7825 and the Mw was 16815.

[0349] <Synthesis Example 12>

[0350] In a 50 mL four-necked flask equipped with a stirring device and a nitrogen inlet tube, DA-5 (2.06 g, 7.97 mmol) and NMP (23.8 g) were added, and while nitrogen was being fed, the mixture was stirred at room temperature until dissolved. Then, after cooling to 15 °C, CA-3 (1.62 g, 7.45 mmol) and NMP (3.29 g) were added, and the mixture was stirred at 50 °C for 20 hours, thereby obtaining a solution of polyamic acid (PAA-12) with a solid component concentration of 12% by mass (viscosity: 203 mPa·s). The Mn of this polyamic acid was 8811 and the Mw was 18997.

[0351] The specifications of the polyamic acids obtained in the above synthesis examples are shown in Table 1. In Table 1, the values in parentheses for the tetracarboxylic acid component and the diamine component represent the amounts used (mole parts) of each tetracarboxylic acid component and each diamine component relative to 100 mole parts of the total amount of the diamine component used in each polymerization step.

[0352] [Table 1]

[0353]

[0354] [Preparation of Liquid Crystal Alignment Agent]

[0355] <Example 1>

[0356] To a solution (6.00 g) of the polyamic acid (PAA-1) obtained in Synthesis Example 1, NMP (8.40 g) and BCS (3.60 g) were added, and the mixture was stirred at room temperature (23 °C) for 2 hours, thereby obtaining a liquid crystal alignment agent (A1).

[0357] <Examples 2 - 3>

[0358] The solution of the polyamic acid used was replaced from (PAA-1) with (PAA-2) - (PAA-3), and otherwise the same procedure as in Example 1 was carried out, thereby obtaining liquid crystal alignment agents (A2) - (A3).

[0359] <Example 4>

[0360] To the solution (5.33 g) of the polyamic acid (PAA-2) obtained in Synthesis Example 2, the solution (6.40 g) of the polyamic acid (PAA-6) obtained in Synthesis Example 6, NMP (15.3 g), BCS (12.0 g), S-1 (3 mass% NMP solution, 0.530 g), and AD-1 (10 mass% NMP solution, 0.480 g) were added, and the mixture was stirred at room temperature for 2 hours to obtain a liquid crystal aligning agent (A4).

[0361] <Examples 5 to 7>

[0362] The solution of the polyamic acid used was replaced from (PAA-1) with (PAA-7) to (PAA-9), and otherwise the same procedure as in Example 1 was carried out to obtain liquid crystal aligning agents (A5) to (A7).

[0363] <Examples 8 to 10>

[0364] The solution of the polyamic acid used was replaced from (PAA-1) with (PAA-10) to (PAA-12), and otherwise the same procedure as in Example 1 was carried out to obtain liquid crystal aligning agents (A8) to (A10).

[0365] <Comparative Examples 1 to 2>

[0366] The solution of the polyamic acid used was replaced from (PAA-1) with (PAA-4) to (PAA-5), and otherwise the same procedure as in Example 1 was carried out to obtain liquid crystal aligning agents (B1) to (B2).

[0367] The specifications of the liquid crystal aligning agents obtained in the above Examples and Comparative Examples are shown in Table 2. In Table 2, the values in parentheses of the polymer components represent the contents (mass%) of the respective polymer components.

[0368] [Table 2]

[0369]

[0370] In the liquid crystal aligning agents (A1) to (A10) and (B1) to (B2) obtained as described above, no abnormalities such as turbidity and precipitation were observed, and they were confirmed to be homogeneous solutions. Using the obtained liquid crystal aligning agents, FFS-driven liquid crystal cells were fabricated and the liquid crystal alignment properties were evaluated. In addition, the liquid crystal alignment stability (AC residual image evaluation) of the FFS-driven liquid crystal cells using the liquid crystal aligning agents (A1) to (A3), (A5) to (A6), (A8) to (A10), and (B1) to (B2) was evaluated.

[0371] [Fabrication of FFS-driven Liquid Crystal Cell]

[0372] (Examples 1 to 7, Comparative Examples 1 to 2)

[0373] A liquid crystal cell having a structure of an FFS mode liquid crystal display element was fabricated.

[0374] First, a substrate with electrodes was prepared. The substrate used was a rectangular glass substrate with dimensions of 30 mm × 35 mm and a thickness of 0.7 mm. On the substrate, as the first layer, an ITO electrode having a pattern in a full-face shape and constituting a common electrode was formed. On the common electrode of the first layer, as the second layer, a SiN (silicon nitride) film formed by CVD (chemical vapor deposition) method was formed. The film thickness of the SiN film of the second layer was 300 nm, which functioned as an interlayer insulating film. On the SiN film of the second layer, as the third layer, a comb-shaped pixel electrode formed by patterning an ITO film was arranged to form two pixels, a first pixel and a second pixel. The size of each pixel was 6 mm in length and 5 mm in width. This substrate with electrodes had a structure in which the common electrode of the first layer and the pixel electrode of the third layer were insulated by the SiN film of the second layer.

[0375] The pixel electrode of the third layer had a comb shape in which electrode lines with a width of 3 μm and bent at an inner angle of 160° within the central portion were arranged in parallel at intervals of 6 μm. One pixel was formed by a plurality of electrode lines and had a first region and a second region with a line connecting the bent portions as a boundary.

[0376] Next, the liquid crystal aligning agents obtained in Examples 1 to 7 and Comparative Examples 1 to 2 above were filtered through a filter with a pore diameter of 1.0 μm and then coated on the above-mentioned substrate with electrodes (hereinafter referred to as the electrode substrate) and a glass substrate (hereinafter referred to as the counter substrate) having columnar spacers with a height of 4 μm and an ITO film formed on the back surface by spin coating. After drying on a hot plate at 80°C for 2 minutes, firing was performed in a hot air circulation oven at 230°C for 30 minutes to form a coating film with a film thickness of 80 nm. On the surface of this coating film, at 300 mJ / cm 2The substrate with a liquid crystal alignment film was obtained by irradiating polarized ultraviolet light with an exposure amount through a 254 nm band-pass filter and a polarizer, and further baking it in an infrared (IR) oven at 230 °C for 30 minutes to perform an alignment treatment. It should be noted that the liquid crystal alignment film formed on the electrode substrate was subjected to an alignment treatment in such a way that the direction bisecting the inner angle of the pixel bending portion was orthogonal to the liquid crystal alignment direction, and when manufacturing the liquid crystal cell, the alignment film formed on the counter substrate was subjected to an alignment treatment in such a way that the liquid crystal alignment direction on the electrode substrate was the same as the liquid crystal alignment direction on the counter substrate. The above two substrates were taken as a group, and a sealant (XN-1500T manufactured by Mitsui Chemicals, Inc.) was printed on the substrates using a dispenser, and the other substrate was bonded in such a way that the alignment directions of their respective liquid crystal alignment films were 0°. Then, the bonded substrates were pressed, and heated in a hot air circulation oven at 150 °C for 60 minutes to cure the sealant, thereby fabricating an empty cell. A positive liquid crystal PA-1492 (manufactured by DIC Corporation) was injected into the empty cell by a vacuum injection method, and the injection port was sealed, thereby obtaining an FFS-driven liquid crystal cell. Then, the obtained liquid crystal cell was heated at 120 °C for 1 hour, and left at 23 °C overnight for evaluation.

[0377] It was confirmed by visual observation that all the FFS-driven liquid crystal cells using the liquid crystal alignment agents (A1) to (A7) obtained in Examples 1 to 7 showed uniform liquid crystal alignment properties.

[0378] (Examples 8 to 10)

[0379] Using the liquid crystal alignment agents obtained in Examples 8 to 10 above, in the same manner as in Examples 1 to 7 and Comparative Examples 1 to 2, a coating film with a film thickness of 80 nm was formed on two substrates, namely the electrode substrate and the counter substrate. Then, the coating film was subjected to a rubbing alignment treatment using a rayon cloth (HY-5318 manufactured by Hyperflex Corporation) (roller diameter: 120 mm, roller rotation speed: 1000 rpm, moving speed: 20 mm / sec, pressing length: 0.2 mm). Then, it was cleaned by irradiating ultrasonic waves in pure water for 1 minute, the water droplets were removed by blowing air, and then dried on a hot plate at 80 °C for 15 minutes, thereby obtaining a substrate with a liquid crystal alignment film. The above two substrates were taken as a group, and an FFS-driven liquid crystal cell was obtained in the same manner as in Examples 1 to 7 and Comparative Examples 1 to 2.

[0380] It was confirmed by visual observation that all the FFS-driven liquid crystal cells using the liquid crystal alignment agents (A8) to (A10) obtained in Examples 8 to 10 showed uniform liquid crystal alignment properties.

[0381] [Evaluation of the stability of liquid crystal alignment]

[0382] This evaluation assesses the residual image (also known as AC residual image) caused by the degradation of the alignment performance of the liquid crystal alignment film during long-term AC driving.

[0383] For the FFS-driven liquid crystal cell fabricated above, an AC voltage of ±4.4 V is applied at a frequency of 30 Hz for 144 hours on a high-brightness backlight (light source: LED, brightness: 27000 cd / m 2 ) with a surface temperature of 50°C. Then, the pixel electrode and the common electrode of the liquid crystal cell are short-circuited and left at room temperature (23°C) for one day. For the liquid crystal cell that has undergone the above treatment, the deviation between the alignment directions of the liquid crystal in the first region and the second region of the pixel in the non-voltage-applied state is calculated in terms of an angle. Specifically, the liquid crystal cell is placed between two polarizing plates arranged with their polarization axes orthogonal, the backlight is lit, and the configuration angle of the liquid crystal cell is adjusted to minimize the transmitted light intensity in the first region of the first pixel. Then, the rotation angle required to minimize the transmitted light intensity in the second region of the first pixel is calculated as the angle Δ. The second pixel is also compared between the first region and the second region in the same way, and the same angle Δ is calculated. And the average value of the angle Δ of the first pixel and the second pixel is calculated as the rotation angle Δ of the liquid crystal cell. It can be said that the smaller the value of this rotation angle Δ, the better the stability of the liquid crystal alignment. The results are shown in Table 3. As an evaluation criterion, the case where the value of the rotation angle Δ of the liquid crystal cell obtained above is 0.09° or less is set as "good", and the case where the value of the rotation angle Δ of the liquid crystal cell obtained above is greater than 0.09° is set as "bad".

[0384] [Table 3]

[0385] Liquid crystal aligning agent Rotation angle △ [°] Example 1 A1 0.03 (good) Example 2 A2 0.04 (good) Example 3 A3 0.04 (good) Example 5 A5 0.06 (good) Example 6 A6 0.07 (good) Example 8 A8 0.02 (good) Example 9 A9 0.04 (good) Example 10 A10 0.01 (good) Comparative Example 1 B1 0.10 (bad) Comparative Example 2 B2 2.78 (bad)

[0386] Compared with the liquid crystal alignment agents (B1) and (B2) obtained in Comparative Examples 1 and 2, the residual images generated by long-term AC driving of the liquid crystal alignment agents (A1)-(A3), (A5)-(A6), (A8)-(A10) obtained in Examples 1-3, 5-6, 8-10 are slight.

[0387] These results show that in the case of using a liquid crystal alignment agent obtained from a specific diamine (1) or a liquid crystal alignment agent obtained from a specific diamine (1') and a specific carboxylic acid (1'), a liquid crystal alignment film with AC residual image suppressed at a higher level than before can be obtained.

[0388] Industrial Applicability

[0389] By using the liquid crystal aligning agent of the present invention, a liquid crystal alignment film capable of suppressing AC afterimages at a higher level than before can be obtained. Therefore, it can be expected to be used in liquid crystal display elements that require a high display quality level, particularly in liquid crystal display elements using the IPS driving method and the FFS driving method. Moreover, these elements are also useful in liquid crystal displays for display purposes, dimming windows that control light transmission and blocking, optical shutters, and the like.

[0390] Description of reference numerals:

[0391] 1: Transverse electric field liquid crystal display element, 2: Comb electrode substrate, 2a: Substrate, 2b: Linear electrode, 2c: Liquid crystal alignment film, 2d: Substrate, 2e: Surface electrode, 2f: Insulating film, 2g: Linear electrode, 2h: Liquid crystal alignment film, 3: Liquid crystal, 4: Opposite substrate, 4a: Liquid crystal alignment film, 4b: Substrate, L: Electric line.

[0392] It should be noted that the entire contents of the specification, claims, drawings, and abstract of Japanese Patent Application No. 2022-188380 filed on November 25, 2022 are incorporated herein by reference as the disclosure of the specification of the present invention.

Claims

1. A liquid crystal aligning agent, characterized in that, the liquid crystal aligning agent contains at least one polymer A selected from the group consisting of a polyimide precursor having a repeating unit a1 represented by the following formula (1) and a polyimide which is an imidized product of the polyimide precursor, X1 represents a tetravalent organic group, R1 and R2 each independently represent a hydrogen atom, a fluorine atom or a monovalent organic group having 1 carbon atom, and at least one of R1 represents a fluorine atom or a monovalent organic group having 1 carbon atom, L represents an alkylene group having 1 to 2 carbon atoms, R and Z each independently represent a hydrogen atom or a monovalent organic group, and a plurality of R1, R and Z each independently have the above definitions.

2. The liquid crystal aligning agent according to claim 1, wherein, in the formula (1), all R2 are hydrogen atoms.

3. The liquid crystal aligning agent according to claim 1 or 2, wherein, the divalent organic group *-(a benzene ring substituted by two R1 and two R2)-O-L-O-(a benzene ring substituted by two R1 and two R2)-* in the formula (1) is any structure among the following formulas (Y1-1) to (Y1-4), and the * represents a bonding bond, * represents a bonding bond.

4. The liquid crystal aligning agent according to claim 1 or 2, wherein, the polymer A is at least one polymer selected from the group consisting of a polyimide precursor further having a repeating unit a2 represented by the following formula (2) and a polyimide which is an imidized product of the polyimide precursor, in formula (2), R and Z have the same meanings as in formula (1), X2 represents a tetravalent organic group, Y2 represents a divalent organic group other than the divalent organic group *-(a benzene ring substituted by two R1)-O-L-O-(a benzene ring substituted by two R1)-* in formula (1), and * represents a bonding bond.

5. The liquid crystal aligning agent according to claim 4, wherein, Said Y2 is a divalent organic group derived from diamine, and the diamine is: phenylenediamine and its derivatives, biphenylenediamine and its derivatives, diamine represented by the following formula (d AL ), diamine having a tetracarboxylic diimide structure, diamine having a photo-orienting group, diamine having a urea bond, diamine having an amide bond, diamine having at least one nitrogen atom-containing structure selected from the group consisting of a nitrogen atom-containing heterocycle, a secondary amino group, and a tertiary amino group, semi-aromatic diamine having a primary amino group and a secondary amino group, semi-aromatic diamine having two primary amino groups, or diamine having a group "-N(D)-". wherein, D in the group "-N(D)-" represents a protecting group that is removed by heating and substituted with a hydrogen atom, the nitrogen atom-containing structure in the diamine having a nitrogen atom-containing structure is a functional group other than the two amino groups participating in the polycondensation reaction, The diamine represented by the formula (d AL ) does not include a diamine having a structure of -N(Z)-(a benzene ring substituted by two R1s and two R2s)-O-L-O-(a benzene ring substituted by two R1s and two R2s)-N(Z)- in the formula (1), wherein the definitions of R1, R2, L and Z are the same as those in the formula (1). Ar1 and Ar 1’ each represents a benzene ring, a biphenyl structure or a naphthalene ring, and one or more hydrogen atoms on the benzene ring, the biphenyl structure or the naphthalene ring are optionally substituted by a monovalent group, and L1 and L 1’ each represents a single bond, -O-, -C(=O)- or -O-C(=O)-, A represents -CH2-, an alkylene group having 2 to 12 carbon atoms or a divalent organic group in which at least any one of -O-, -C(=O)-O- and -O-C(=O)- is inserted between the carbon-carbon bonds of the alkylene group, and any hydrogen atom possessed by A is optionally substituted by a halogen atom one or more hydrogen atoms on the benzene ring, biphenyl structure or naphthalene ring are optionally substituted with a monovalent group, and examples of the monovalent group include: a halogen atom, an alkyl group having 1 to 3 carbon atoms, an alkenyl group having 2 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a fluoroalkyl group having 1 to 3 carbon atoms, a fluoroalkenyl group having 2 to 3 carbon atoms, a fluoroalkoxy group having 1 to 3 carbon atoms, an alkyloxycarbonyl group having 2 to 3 carbon atoms, a cyano group, a nitro group, etc.

6. The liquid crystal aligning agent according to claim 1 or 2, wherein, X1 is a tetravalent tetracarboxylic acid residue derived from an acyclic aliphatic tetracarboxylic dianhydride, a cycloaliphatic tetracarboxylic dianhydride, an aromatic tetracarboxylic dianhydride or a derivative of these substances.

7. The liquid crystal aligning agent according to claim 1 or 2, wherein, the polymer A contains 10 to 95 mol% of the total of the repeating unit a1 and the imidized structural unit of the repeating unit a1 based on all the repeating units of the polymer A.

8. A liquid crystal aligning agent, characterized in that the liquid crystal aligning agent contains at least one polymer A' selected from the group consisting of a polyimide precursor having a repeating unit a1' represented by the following formula (1') and a polyimide which is an imidized product of the polyimide precursor, X 1’ represents a tetravalent organic group selected from the following formulas (X-1) to (X-9), R 1’ and R 2’ each independently represents a hydrogen atom, a fluorine atom or a monovalent organic group having 1 carbon atom, and at least one of the Rs 1’ represents a fluorine atom or a monovalent organic group having 1 carbon atom L' represents an alkylene group having 1 to 12 carbon atoms, a cyclohexylene group, a phenylene group, a biphenyl structure or a naphthylene group, R' and Z' each independently represent a hydrogen atom or a monovalent organic group, Multiple Rs 1’ and R 2’ , R', and Z' each independently have the above definitions R1 to R4 each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, a monovalent organic group having 1 to 6 carbon atoms containing a fluorine atom or a phenyl group, and at least one of R1 to R4 represents a group other than a hydrogen atom as defined above, and * represents a bonding bond.

9. The liquid crystal aligning agent according to claim 8, wherein In the formula (1’), all Rs 2’ are hydrogen atoms, and L’ is an alkylene group having 1 to 12 carbon atoms.

10. The liquid crystal aligning agent according to claim 8 or 9, wherein the formula (x - 1) is selected from the group consisting of the following formulas (x1 - 1) to (x1 - 5), * represents a bonding bond.

11. The liquid crystal aligning agent according to claim 8, wherein The divalent organic group *-(benzene ring substituted by two Rs 1’ )-O-L'-O-(benzene ring substituted by two Rs 1’ )-* in the formula (1') has any structure among the following formulas (Y1'-1) to (Y1'-3). * represents a bonding bond.

12. The liquid crystal aligning agent according to claim 8, wherein the polymer A' is at least one polymer selected from the group consisting of a polyimide precursor further having a repeating unit a2' represented by the following formula (2') and a polyimide which is an imidized product of the polyimide precursor, in formula (2'), R' has the same meaning as R' in the above formula (1'), and Z' has the same meaning as Z' in the above formula (1'), X 2’ represents a tetravalent organic group, Y 2’ represents a divalent organic group, satisfying any one of the following conditions (i) or (ii), (i) In Y 2’ represents the divalent organic group *-(benzene ring substituted by two Rs 1’ -O-L'-O-(benzene ring substituted by two Rs 1’ )-* in the formula (1'), X 2’ represents a tetravalent organic group selected from any of the tetravalent organic groups represented by the following formulas (X-10) to (X-27), or a tetravalent tetracarboxylic acid residue derived from an aromatic tetracarboxylic dianhydride or its derivative (ii) In Y 2’ represents a divalent organic group other than the divalent organic group *-(benzene ring substituted by two Rs 1’ substituted benzene ring)-O-L'-O-(benzene ring substituted by two Rs 1’ substituted benzene ring)-*, X 2’ represents a tetravalent organic group, * represents a bonding bond, * represents a bonding bond.

13. The liquid crystal aligning agent according to claim 8, wherein the polymer A' contains 10 to 95 mol% of the total of the repeating unit a1' and the imidized structural unit of the repeating unit a1' based on all the repeating units of the polymer A'.

14. The liquid crystal aligning agent according to claim 1 or 2, wherein the liquid crystal aligning agent further contains at least one polymer B selected from the group consisting of a polyimide precursor having a repeating unit b1 represented by the following formula (3) and a polyimide which is an imidized product of the polyimide precursor, X3 is a tetravalent organic group, Y3 is a divalent organic group, R and Z each independently represent a hydrogen atom or a monovalent organic group, and a plurality of R and Z each independently have the above-defined meanings, wherein the formula (3) is different from the formula (1) and the formula (1').

15. The liquid crystal aligning agent according to claim 1 or 2, wherein the liquid crystal aligning agent is used for a liquid crystal alignment film for a photoalignment treatment method.

16. A liquid crystal alignment film obtained from the liquid crystal aligning agent according to claim 1 or 2.

17. A liquid crystal display element having the liquid crystal alignment film according to claim 16.

18. A method for manufacturing a liquid crystal alignment film, comprising the following steps (1) to (3), Step (1): A step of coating the liquid crystal aligning agent according to claim 1 or 2 on a substrate; Step (2): A step of firing the coated liquid crystal aligning agent; and Step (3): A step of subjecting the film obtained in step (2) to an alignment treatment as needed.

19. The method for manufacturing a liquid crystal alignment film according to claim 18, wherein the alignment treatment is a photo-alignment treatment.

20. The method for manufacturing a liquid crystal alignment film according to claim 18, wherein the liquid crystal alignment film is used for a liquid crystal display element of an IPS driving method or an FFS driving method.

21. A method for manufacturing a liquid crystal display element, which includes a step of forming the liquid crystal alignment film according to claim 16.

22. A diamine represented by the following formulas (DA-6) and (DA-13) 23. A polymer obtained from a diamine component containing the diamine according to claim 22.

24. A polyimide precursor or polyimide, wherein, The polyimide is an imidized product of the polyimide precursor, The polyimide precursor or polyimide is obtained by a polycondensation reaction of a diamine component containing the diamine according to claim 22 and a tetracarboxylic acid component.

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